Description of wetland ecological character · maintaining the ecological character of the site....

Description of wetland ecological character

Yanga National Park

© Copyright State of NSW and the Office of Environment and Heritage, Department of Premier and Cabinet

With the exception of photographs, the Office of Environment and Heritage, Department of Premier and Cabinet (OEH) and State of NSW are pleased to allow this material to be reproduced in whole or in part for educational and non-commercial use, provided the meaning is unchanged and its source, publisher and authorship are acknowledged. Specific permission is required for the reproduction of photographs.

This publication has been compiled in good faith, exercising all due care and attention. No representation is made about the accuracy, completeness or suitability of the information in this publication for any particular purpose. OEH shall not be liable for any damage which may occur to any person or organisation taking action or not on the basis of this publication. Readers should seek appropriate advice when applying the information to their specific needs.

This project was funded by the Rivers Environmental Restoration Program which is jointly funded by the NSW Government and the Australian Government’s Water for the Future Program. It aims to arrest the decline of wetlands through water recovery, effective management of environmental water and the sustainable management of our wetlands.

The authors would like to thank the following people who contributed to this report: Paul Childs: Wetland Ecologist, OEH James Maguire: Senior Wetlands and Rivers Conservation Officer, OEH Russell Hampton, Paul McInnes and Narelle Jones: Yanga National Park, OEH Tom Davy: State Water Corporation Jennifer Spencer, Jordan Iles, Lisa Knowles and others: Rivers and Wetlands Unit, OEH

Wen L, Saintilan N and Ling J 2011. Description of wetland ecological character: Yanga National Park. Rivers and Wetlands Unit, Office of Environment and Heritage, Department of Premier and Cabinet. Sydney, Australia.

Cover photographs Main: Two Bridges Swamp – J Kelleway/OEH Right: top: Pococks Swamp, centre: River red gums at Two Bridges Swamp,

bottom: Azolla at Pococks Swamp – L Wen/OEH

Published by:

Office of Environment and Heritage Department of Premier and Cabinet 59–61 Goulburn Street, Sydney PO Box A290, Sydney South 1232

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Phone: (02) 9995 5000 (switchboard) Phone: 131 555 (environment information and publications requests) Phone: 1300 361 967 (national parks, climate change and energy efficiency information and publications requests) Fax: (02) 9995 5999 TTY: (02) 9211 4723 Email: [email protected] Website: www.environment.nsw.gov.au

ISBN 978 1 74293 398 6 OEH 2012/0165

Published February 2012, based on information compiled in 2009

SummaryYanga National Park forms part of the Lowbidgee floodplain which is listed in the Directory of Important Wetlands in Australia. This description of ecological character focuses on the national park with reference to the broader Lowbidgee floodplain. It is based on the national framework and guideline for describing the ecological character of Australia’s Ramsar wetlands and has identified ecosystem benefits and services, ecological components and processes and their limits of acceptable change at its current state.

Yanga National Park meets five of the six criteria for determining nationally important wetlands. There are 12 wetland types according to Ramsar classification (10 according to Environment Australia) in the park. The dominant wetland type, river red gum (Eucalyptus camaludensis) forest/woodland, forms one of the largest stands in Australia. Other significant wetlands include Yanga Lake, Piggery Swamp and seasonal flooded lignum (Muehlenbeckia florulenta) woodland.

Approximately 17 vegetation communities have been identified in Yanga National Park ranging from river red gum riparian open forest, old man saltbush (Atriplexnummularia), lignum shrub to spike rush (Eleocharis sphacelata) swamp. Over time, 303 vascular plant species, including four endangered and one vulnerable, have been recorded within these communities. The diverse ranges of vegetation provide habitats for various animals. There are 269 fauna species (excluding fish) which have been recorded in the site, including 25 mammals, 24 reptiles, 11 amphibians and 210 birds.

Yanga National Park supports the populations of a number of internationally and nationally threatened species included in the global ‘red list’ of the International Union for Conservation or listed under the Commonwealth Environment Protection and Biodiversity Conservation Act 1999. There is a total of 21 endangered and vulnerable species, 12 of which are waterbirds, which have been recorded in Yanga National Park, such as Australasian bittern (Botaurus poiciloptilus), freckled duck (Stictonettanaevosa) and blue-billed duck (Oxyura australis). The southern bell frog (Litoriaraniformis), which is considered to be endangered at state level, has been recorded in Piggery Swamp, Mercedes Swamp and Twin-bridge Swamp.

There are 61 species of waterbirds observed using the site as roosting, feeding and nesting/breeding habitat. Important areas include Tarwillie Swamp, Shaw’s Swamp, Piggery Lake, Two-Bridge Swamp located between Redbank Weir and Lambing Down Hill, and river red gum forests within 10 km of Redbank Weir along the Murrumbidgee River.

The site also supports a broad range of recreational, educational and scientific activities, and has a high social and cultural value. The site has become a major national focus for floodplain ecological research activities since 2007 when it was gazetted as a national park. Substantial levels of scientific study and investigation have been undertaken in the park, particularly relating to natural heritage values. Sites of Aboriginal and European heritage are also found within the area.

Currently, the site is highly stressed as evidenced by large scale degradation of vegetation condition, sharp decrease in the abundance of waterbirds, and wide dispersion of the exotic European carp. Hydrological alteration due to upstream water division and fragmentation caused by engineering works within the floodplain are identified as the major threatens. The geological setting of the site means that

environmental water provision is the most practical method for recovering and maintaining the ecological character of the site.

There are a number of knowledge gaps and monitoring requirements regarding the important components and critical processes of the site which limit the current capacity to establish benchmarks, detect changes and set ‘limits of acceptable change’ for ecological character. Flow path and inundation pattern, extent of aquatic vegetation communities, number of waterbird species and abundance, and condition of river red gum forest are given high priorities.

Management (D)EWAs

Re-snaggingDam removalLevee breach

Weed and pest controlErosion control

Climate (D)Rainfall

TemperatureEvaporation

WindSolar radiationExtreme events

Geomorphology (D)Fractures and faults

Surface geology (bedrock & soil types)Topography

Aquifers

Human disturbance (D)River regulationWater diversion

Drainage networkInfrastructure

GrazingClearingBurning

Agricultural runoffHydrogeologic Settings (D)

Wetland Ecosystem

Hydrological regimes (C)Frequency, duration and depth of inundation

Groundwater recharge/dischargeDry-wet cycles

Soil (sediment) Chemistry (C/P)

N, P, Ca, Si etc availabilityNutrient cycleCarbon cycle

Soil type and distribution

Physical forms (C/P)Erosion

SedimentationWetland size and distribution

Habitat availability Habitat connectivity

Water Chemistry (C/P)Salinity

NutrientsTurbidity

Water quality

Primary Production and Trophic Structure (C)

Producers (C)Phytoplankton

PeriphytonVegetation

Tertiary consumers (C)Reptile and mammals

FishLand bird and Waterbird

Amphibians

Primary / secondary (C)consumers

ZooplanktonMacroinvertebrates

Invertebrates

Services and BenefitsBiodiversity conservation: unique wetland types, diverse habitats, ecological communities, drought refuge

Nature observation: education and scientific researchRecreation and tourism

Cultural

Decomposers (C)

Fungi

Bacteria

Management (D)EWAs



Climate (D)Rainfall





Aquifers





Wetland Ecosystem










NutrientsTurbidity

Water quality






Amphibians



Invertebrates



Cultural

Decomposers (C)

Fungi

Bacteria

The overall ecological conceptual model developed for the description of ecological character of Yanga National Park. Feedback from biota to their environment and interactions among biological communities were omitted for simplicity. D, Driver; C, Component; P, Process.

��

� �� 1.1 Brief description of Yanga National Park ........................................................... 11.2 Objectives of description of ecological character ............................................... 31.3 Concepts applied and approaches for description of ecological character ........ 3

1.3.1 Ecological character............................................................................... 31.3.2 Approaches taken in a description of ecological character .................... 5

1.4 Policy framework................................................................................................ 6

� �� 2.1 Site location and its catchment .......................................................................... 9

2.1.1 Site location and boundary..................................................................... 92.1.2 Murrumbidgee catchment ...................................................................... 9

2.2 Climate............................................................................................................. 122.3 Geology............................................................................................................ 142.4 Landform.......................................................................................................... 152.5 Land tenure...................................................................................................... 15

2.5.1 Land use before dedication as a national park .................................... 152.6 Wetland types within Yanga National Park ...................................................... 192.7 Ecosystem services ......................................................................................... 19

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4.1 Regulating services.......................................................................................... 234.1.1 Maintaining regional water quality........................................................ 234.1.2 Replenish groundwater ........................................................................ 234.1.3 Flood control ........................................................................................ 254.1.4 Regulate climate .................................................................................. 25

4.2 Supporting services ......................................................................................... 264.2.1 Provides a combination of wetland types, which is typical in the

NSW Riverina Bioregion ...................................................................... 264.2.2 Supports biota species that maintain biodiversity of the NSW

Riverina Bioregion................................................................................ 264.2.3 Supports two endangered ecological communities.............................. 274.2.4 Supports 21 threatened fauna species ................................................ 294.2.5 Supports four endangered and vulnerable plant species..................... 294.2.6 Supports at least one threatened fish species ..................................... 314.2.7 Supports an abundance of waterbirds ................................................. 314.2.8 Supports eleven migratory species covered in migratory bird

agreements .......................................................................................... 344.2.9 Supports large stands of primary producers ........................................ 344.2.10 Provides important feeding, spawning and nursing grounds for

native fish ............................................................................................. 354.3 Cultural services .............................................................................................. 36

4.3.1 Aboriginal heritage ............................................................................... 364.3.2 European heritage................................................................................ 364.3.3 Scientific research................................................................................ 36

5 Description of specified components that support selectedecosystem services................................................................................................ 375.1 Physical components of Yanga National Park ................................................. 37

5.1.1 Important wetlands............................................................................... 375.1.2 Large woody debris.............................................................................. 455.1.3 Fire ....................................................................................................... 46

5.2 Chemical components ..................................................................................... 465.2.1 Soil chemistry....................................................................................... 465.2.2 Water quality ........................................................................................ 47

5.3 Biological component of Yanga National Park ................................................. 505.3.1 Important plant communities ................................................................ 505.3.2 Waterbirds............................................................................................ 575.3.3 Fish ...................................................................................................... 605.3.4 Frogs .................................................................................................... 605.3.5 Reptiles ................................................................................................ 625.3.6 Mammals.............................................................................................. 62

6 Critical ecosystem processes ............................................................................... 656.1 Hydrological processes.................................................................................... 65

6.1.1 Natural overbank flows......................................................................... 656.1.2 Artificial Watering ................................................................................. 70

6.2 Geomorphologic processes ............................................................................. 716.2.1 Sedimentation ...................................................................................... 71

6.3 Nutrient cycling and trophic dynamics.............................................................. 74

7 Limits of acceptable change to key ecological components ............................. 758 Actual and likely threats to the ecological character of Yanga National Park.. 80

8.1 Alteration to the natural flow regimes............................................................... 808.2 Habitat loss and fragmentation ........................................................................ 818.3 Introduced and problematic species ................................................................ 858.4 Climate change ................................................................................................ 85

8.4.1 Higher temperatures ............................................................................ 868.4.2 Changes to rainfall patterns and intensity ............................................ 86

8.5 Other issues..................................................................................................... 86

9 Knowledge gaps ..................................................................................................... 8810 Recommended monitoring program..................................................................... 90

10.1 Monitoring objectives ....................................................................................... 9010.2 Recommended monitoring framework ............................................................. 90

11 Communication, education and public awareness messages........................... 9411.1 Major CEPA activities for Yanga National Park ............................................... 9411.2 Important CEPA messages.............................................................................. 95

Appendix 1 Plant species in Yanga National Park .............................................. 96Appendix 2 Bird species in Yanga National Park............................................�� 103References .........................................................................................................��108

TablesTable 1: Details of the description of wetland ecological character of

Yanga National Park ....................................................................................... 2Table 2: Major land use in the Murrumbidgee catchment ........................................... 11Table 3: Description of soil landscapes in Yanga Nation Park.................................... 15Table 4: Detailed land use in Yanga National Park before purchase by DEC ............ 17Table 5: Wetland types found within Yanga National Park in order of dominance ..... 20Table 6: Ecosystem benefits and services.................................................................. 24Table 7: Fauna and flora records in Yanga National Park and the NSW

Riverina Bioregion......................................................................................... 27Table 8: Endangered and vulnerable fauna found within Yanga National Park.......... 30Table 9: Endangered and vulnerable plant species found in Yanga National Park .... 30Table 10: Waterbird species of national, state and regional importance recorded

in the 1989–90 survey in Yanga National Park ............................................. 32Table 11: Migratory birds protected under international treaties................................... 34Table 12: Ecosystem components of Yanga National Park .......................................... 38Table 13: Important wetlands within Yanga National Park............................................ 40Table 14: Soil chemistry characteristics in Yanga National Park, average values

for a 1-m soil profile...................................................................................... 47Table 15: Plant communities found within Yanga National Park................................... 52Table 16: Major bird surveys in Lowbidgee region which have sites in

Yanga National Park ..................................................................................... 58Table 17: Waterbird species recorded in Yanga National Park and

surrounding floodplains................................................................................. 58Table 18: Fish species in the Lowbidgee region, including the

Murrumbidgee channel ................................................................................. 61Table 19: Frog species in Yanga National Park and surrounding floodplains............... 62Table 20: Reptiles recorded in Yanga National Park and surrounding floodplains ....... 63Table 21: Mammal species in Yanga National Park and surroundings......................... 64Table 22: Hydrological processes in Yanga National Park ........................................... 66Table 23: Major developments on the Murrumbidgee River 1855–1982 ...................... 68Table 24: Changes in selected hydrological indicators in the Murrumbidgee

downstream of Redbank Weir....................................................................... 69Table 25: Limits of acceptable change for critical components and processes of

Yanga National Park ..................................................................................... 76Table 26: Summary of actual and likely threats to the ecological character of the

Lowbidgee floodplain .................................................................................... 82Table 27: Key knowledge gaps and recommended monitoring and actions................. 89Table 28: Recommended monitoring program for Yanga National Park ...................... 91

FiguresFigure 1: Relationship of the ecological character description to other documents ....... 4

Figure 2: Relationships among ecological components, processes and services that comprise the ecological character of a wetland ecosystem..................... 4

Figure 3: Yanga National Park and the main waterways ............................................. 10

Figure 4: The Murrumbidgee catchment and main land use........................................ 11

Figure 5: Monthly rainfall distribution at Balranald, average for 119 years from 1889 to 2006 ................................................................................................. 12

Figure 6: Mean monthly radiation and evaporation at Balranald, average of 118 years from 1889 to 2006 ........................................................................ 13

Figure 7: Mean maximum and minimum temperatures at Balranald, average for 118 years from 1889 to 2006 ........................................................................ 13

Figure 8: Soil landscape in Lowbidgee ........................................................................ 16

Figure 9: Land use in Yanga National Park before dedication as a national park........ 18

Figure 10: Overall ecological conceptual model for Yanga National Park ..................... 22

Figure 11: Schematic of the conceptual model for groundwater, illustrating the major recharge areas in the floodplain.................................................................... 24

Figure 12: The effect of wetlands on peak stormwater flows ......................................... 25

Figure 13: Twin-bridges Swamp, a freshwater wetland in Yanga National Park, which accommodates the threatened aquatic ecological community including the southern bell frog ..................................................................... 28

Figure 14: Important waterbird feeding and breeding sites in Yanga National Park identified during the 1989–90 survey ............................................................ 33

Figure 15: Floodplain wetlands as fish feeding, spawning and nursery habitat ............. 35

Figure 16: Yanga homestead......................................................................................... 36

Figure 17: Locations of the 23 wetlands listed in Table 13 ............................................ 39

Figure 18: The early development of saltbush at Yanga Lake in 2007 .......................... 43

Figure 19: Tala Lake in 2007, showing dead river red gums caused by permanent inundation before it dried out in 2001............................................................ 43

Figure 20: Piggery Lake when inundated and dry.......................................................... 44

Figure 21: Two Bridges swamp before (left) and after (right) receiving environmental water allocation...................................................................... 44

Figure 22: Mercedes Swamp before (left) and after (right) receiving environmental water allocation ............................................................................................. 44

Figure 23: Piles of river red gum branches which provide habitat for amphibians, reptiles, birds and small mammals................................................................ 45

Figure 24: A fallen tree in the Murrumbidgee River channel downstream from Redbank Weir providing a surface for algae, microscopic plants and animals ............ 46

Figure 25: Soil sampling sites at Yanga National Park .................................................. 48

Figure 26: Vegetation distribution in Yanga National Park............................................. 51

Figure 27: Condition of river red gums in 2005 based on aerial photography................ 55

Figure 28: Lignum swamp at the Fingerboards in Lowbidgee with black box in the background ................................................................................................... 56

Figure 29: Lignum swamps, which provide important waterbird breeding habitat in the Lowbidgee floodplain .......................................................................... 56

Figure 30: Relationships between hydrological cycle and other floodplain ecological processes under a natural flood regime........................................................ 67

Figure 31: Monthly flow distribution before and after 1970 ............................................ 69

Figure 32: Irrigation water distribution pattern in Yanga National Park .......................... 70

Figure 33: Water diverted to Yanga National Park from the Murrumbidgee River ......... 71

Figure 34: Sediment erosion and deposition processes in the river–floodplain system. 73

Figure 35: The three geomorphic regions of the Murrumbidgee catchment .................. 73

Figure 36: Limits of acceptable change ......................................................................... 75

Figure 37: Conceptual ecological model of risks in Yanga National Park ...................... 84

Figure 38: Linkages between climate change and ecosystem responses ..................... 86

AbbreviationsCAMBA China–Australia Migratory Bird Agreement CEPA communication, education and public awareness DECC Department of Environment and Conservation NSW DLWC Department of Land and Water Conservation NSW DO dissolved oxygen EEC endangered ecological community EPBC Act Environment Protection and Biodiversity Conservation Act 1999 (Cwlth) ESP exchangeable sodium percentage EWA environmental water allocation FCID Flood Control and Irrigation District JAMBA Japan–Australia Migratory Bird Agreement MEA Millennium Ecosystem Assessment MIA Murrumbidgee Irrigation Area NPW Act National Parks and Wildlife Act 1974 (NSW) NPWS NSW National Parks and Wildlife Service OEH Office of Environment and Heritage, Department of Premier

and CabinetRERP Rivers Environmental Restoration Program ROKAMBA Republic of Korea – Australia Migratory Bird Agreement TP Total phosphorus TSC Act Threatened Species Conservation Act 1995 (NSW)

Yanga National Park 1

1 IntroductionThis project seeks to define the ecological character of wetlands on the lower Murrumbidgee (Lowbidgee) floodplain with the focus on the newly designated Yanga National Park. The sustainable management of the region’s wetlands is contingent upon a sound understanding of the key ecological components, the processes which sustain those values, and the natural variability primarily driven by a variable hydrological regime. Detailed knowledge is essential to understand a wetland’s water requirement and how a wetland will response to water management change, and thus can greatly enhance the ability to manage environmental water allocations (EWAs). The report also identifies the actual and potential threats to the existence and integrity of a region’s wetlands and identifies and recommends indicators for monitoring change in ecological character. The report developed for the region should also identify management actions that could be incorporated within management plans.

This report was compiled by the Department of Environment and Climate Change NSW, now the Office of Environment and Heritage (OEH), following the Australian national framework and guideline for describing the ecological character of Ramsar wetlands (DEWHA 2008). While this report is not an ecological character description (ECD) within the Ramsar context, the Commonwealth guidelines for Ramsar wetlands provides a sound basis for a literature review, recognition of key ecological assets, definition of natural variability, and identification of key indicators of change and knowledge gaps. Although the Lowbidgee area doesn’t contain Ramsar sites, wetlands of regional, state, and national importance are widespread (Pressey et al. 1984; Maher 1990; Kingsford and Thomas 2001).

The project is a component of the NSW Rivers Environmental Restoration Program (RERP) subprogram, Better use of environmental water. This subprogram is a joint NSW and Commonwealth Government initiative aimed at maximising the environmental benefit for the investment of water through market based water recovery. The Lowbidgee floodplain has been identified as one of a limited number of sites within this program where detailed ecological investigations will contribute to the efficient and targeted delivery of environmental water. The overall objective of this wetland description of the Lowbidgee is to review and systematise available information in support of the sustainable management of the key wetland sites.

1.1 Brief description of Yanga National Park

Yanga National Park is part of the Lowbidgee floodplain. Recognised for its regional ecological values and conservation importance, the site was purchased by the NSW Government in 2005, and Yanga National Park was gazetted in February 2007. The newly created national park also includes Yanga Nature Reserve (1932 ha) created in 1974 under the National Parks and Wildlife Act 1974 (NSW) (NPW Act).

The Lowbidgee floodplain is renowned for its wetlands as critical fish and waterbird habitats and refuge for biodiversity in arid and semi-arid Australia (Maher 1990; Kingsford and Thomas 2001; Watts et al. 2001; Gilligan 2005). In their natural state, many of the wetlands in the region are characterised by variable and unpredictable patterns of high and low flows and water levels. The natural morphology of the river system includes deep channels, deep pool areas, sandy–muddy banks, terraces formed by floods, suspended load depositional ‘benches’, higher floodplain benches, paleochannels, flood runners, anabranches, billabongs and lakes. The complex river–floodplain morphology provides an array of habitats that play a critical role in the life cycles of the many fish and waterbird species. Over the last 50–100 years the wetlands on the Lowbidgee floodplain have changed significantly from their natural state. The

2 Description of wetland ecological character

ecosystem is experiencing degradation due to instream regulation structures (e.g. dams and weirs), upstream water diversions, flood prevention structures (e.g. levees), deterioration of water quality, clearing of riparian vegetation and grazing, and the presence of exotic species (Pressey et al. 1984; Maher 1990; Hillman et al. 2000; Kingsford and Thomas 2001; Frazier and Page 2006; Wen et al. 2009).

Table 1 provides basic information about the site regarding the preparation of the description of wetland ecological character.

Table 1: Details of the description of wetland ecological character of Yanga National Park

Site name Yanga National Park

Location Yanga National Park is located in the floodplain of the lower reach of the Murrumbidgee River between Maude and Balranald Weir, approximately 110 kilometres west of Hay, inland NSW.

Area 66,734 ha, includes 1932 ha of Yanga Nature Reserve

Geographic coordinates 34° 39’S, 143° 35’E

Altitude 0–70m ASL

Date of listing as a Ramsar site Not listed.

Year of listing as national important wetland 1991

Date for which the description of ecological character applies February 2009

Management authorities Office of Environment and Heritage Department of Premier and Cabinet

Status of description This is the first description of the ecological character of Yanga National Park.

Name of compiler

Wen L, Ling JE and Saintilan N Rivers and Wetlands Unit Water and Catchments Science Division Office of Environment and Heritage Department of Premier and Cabinet

Date of compilation February 2009

Reference for Information Sheet

A Directory of Important Wetlands in Australia: Lowbidgee Floodplain Wetland

Department of Environment and Water Resources, http://deh.gov.au/water/wetlands/database/index.html

Reference for management plan OEH is developing a plan of management.


1.2 Objectives of description of ecological character

Investigating, understanding and documenting ecological character is the cornerstone to maintaining and protecting the values of wetland ecosystems. The description of ecological character underpins the development of a wetland management plan by providing baseline information about the components and processes, services and benefits, risks and threats of the site. It also identifies the key knowledge gaps and helps the development of a monitoring, evaluation and reporting framework. Figure 1 shows the relationships between the description of ecological character and other planning and management processes and documents.

The wetland ecological description will form the reference for: � development (or update) and implementation of an environmental management

plan designed to maintain the ecological character of the region � development (or update) and implementation of monitoring programs to detect

changes in ecological character � assessment of the effectiveness of management actions, especially environmental

water allocation � regular evaluation of the results of monitoring programs to assist adaptive

management.

This description of ecological character contributed to the RERP subprogram Betteruse of environmental water through enhancing the knowledge of water requirements to maintain the ecological character of wetlands within Lowbidgee, particularly in Yanga National Park, in terms of: � identifying and describing key ecological assets and their values and services � identifying key ecological components and critical ecological processes that sustain

these ecological values � providing conceptual models describing relationships between processes and

populations of plants and animals – resident and itinerant � identifying key actual and potential threats to the site � identifying key knowledge gaps and making recommendations for key monitoring

needs� benchmarking and tracking changes in ecological character in recent decades.

1.3 Concepts applied and approaches for description of ecological character

The main concepts in this description of ecological character were adapted from the Ramsar Convention and its associated documents such as the Millennium Ecosystem Assessment report to the Ramsar Convention (MEA 2005). The steps taken to describe the ecological character are adapted from those outlined in the Nationalframework and guideance for describing the ecological character of Australian Ramsar wetlands (DEWHA 2008).

1.3.1 Ecological character Wetlands are by their very nature both productive and dynamic systems, and the Ramsar Convention definition of ecological character as ‘the combination of the ecosystem components, processes and benefits/services that characterise the wetland at a given point in time’ (Ramsar Convention 2005, Resolution IX.1 Annex A) acknowledges these attributes. The definition emphasises the links between the ecological components, their processes or interactions and the benefits or services they support (Figure 2).

Other key definitions of associated terms are outlined below.


Wetland Information Sheet

Ecological Character

Description (ECD)

Environment Management Plan

Environmental Water Management Plan

Framework and Guidance for ECD

Natural Resource Management and

PlanningOther land use planning(e.g. Local Government)

Condition reporting

Communication and awareness raising

Research

Monitoring

Environmental Impact Assessment

EPBC Act Regulatory Role

e.g. Compliance action under the EPBC Act

Wetland Information Sheet


Description (ECD)

Environment Management Plan

Environmental Water Management Plan

Framework and Guidance for ECD

Natural Resource Management and

PlanningOther land use planning(e.g. Local Government)

Condition reporting

Communication and awareness raising

Research

Monitoring

Environmental Impact Assessment

EPBC Act Regulatory Role

e.g. Compliance action under the EPBC Act

Source: modified from Lambert and Elix (2006)

Figure 1: Relationship of the ecological character description to other documents

System Drivers

• Climateo Rainfallo Evaporationo Temperatureo Solar radiationo Windo Extreme weather

• Hydrogeomorphologyo Topographyo Soilo Aquifero Hydrology

• Management o Conservation

• Natural and human disturbance

o Floodo Fireo Clearingo Recreation

Component and Processes

Services and Benefits

• Provisioningo Fisheryo Timber

• Regulatingo Water qualityo Flood controlo Local climate

• Supporting o Biodiversityo Naturalnesso Unique landscape

• Cultural o Aboriginal heritageo Historical siteso Recreation and

educationo Scientific studies

• Salinity, DO & pH fluctuations

• Inundation dynamics• Hydrological regimes• Sedimentation• Nutrient cycling• Primary production• Biological interactions

• Vegetation community• Phytoplankton• Birds• Fish• Reptile, amphibian and

mammals• Invertebrates• Water chemistry• Soil chemistry


System Drivers

• Climateo Rainfallo Evaporationo Temperatureo Solar radiationo Windo Extreme weather

• Hydrogeomorphologyo Topographyo Soilo Aquifero Hydrology

• Management o Conservation

• Natural and human disturbance

o Floodo Fireo Clearingo Recreation

Component and Processes

Services and Benefits

• Provisioningo Fisheryo Timber

• Regulatingo Water qualityo Flood controlo Local climate

• Supporting o Biodiversityo Naturalnesso Unique landscape

• Cultural o Aboriginal heritageo Historical siteso Recreation and

educationo Scientific studies

• Salinity, DO & pH fluctuations

• Inundation dynamics• Hydrological regimes• Sedimentation• Nutrient cycling• Primary production• Biological interactions

• Vegetation community• Phytoplankton• Birds• Fish• Reptile, amphibian and

mammals• Invertebrates• Water chemistry• Soil chemistry


Source: after Philips et al. (2005)

Figure 2: Relationships among ecological components, processes and services that comprise the ecological character of a wetland ecosystem


Ecosystems are described in the Millennium Ecosystem Assessment (MEA 2003) as the complex of living communities (including human communities) and non-living environment (ecosystem components) interacting (through ecological processes) as a functional unit which provides a variety of benefits to people (ecosystem services) (Ramsar Convention 2005).

Ecosystem components include the physical, chemical and biological parts of a wetland (from large scale to very small scale, e.g. habitat, species and genes) (MEA 2003, 2005; Resolution IX.1 Annex A).

Ecosystem processes are the dynamic forces within an ecosystem. They include all those processes that occur between organisms and within and between populations and communities, including interactions with the non-living environment, which result in existing ecosystems and bring about changes in ecosystems over time (Australian Heritage Commission 2002). They may be physical, chemical or biological (Ramsar Convention 1996, Resolution VI.1 Annex A).

Benefits/services are defined in accordance with the Millennium Ecosystem Assessment definition of ecosystem services as ‘the benefits that people receive from ecosystems’ (MEA 2005; Ramsar Convention 2005, Resolution IX.1 Annex A). However, in the context of the Ramsar Convention this term also refers to products, functions, and attributes as defined in Ramsar Resolution VI.1 and includes both material and non-material cultural values, benefits and functions as outlined in CoP8 DOC.15: Cultural aspects of wetlands (Ramsar Convention 2005, Resolution IX.1 Annex A).

Change in ecological character is defined as the human-induced adverse alteration of any ecosystem component, process, and/or ecosystem benefit/service (Ramsar Convention 2005, Resolution IX.1 Annex A).

1.3.2 Approaches taken in a description of ecological character

The Ramsar Convention has defined ecological character and change in ecological character, and provided frameworks and guidelines for management planning, establishing monitoring programs and undertaking risk assessments. However, definitive guidance on how to describe ecological character has not been forthcoming from the Convention to date despite recognition that it is needed.

The main steps in writing this report (DEWHA 2008) were as follows. 1 Prepare an introduction to the description: site details, purpose of the description,

relevant legislation, and methods. 2 Describe the site: location, climate, maps and images, tenure, wetland criteria

and types. 3 Identify and describe the critical components, processes and services. 4 Develop a conceptual model for the wetland: depict the critical components and

processes of the wetland and their relationships. 5 Set limits of acceptable change: determine limits of acceptable change for critical

components, processes and services of the site. 6 Identify threats to the ecological character of the site using information from

steps 3–5. 7 Describe changes to ecological character if appropriate. This step refers to

changes in ecological character since the time of listing of a site as a Ramsar


wetland. As this is not relevant in the case of the lower Lachlan River, a summary of documented changes in ecological character is provided instead.

8 Summarise the knowledge gaps using information from steps 3–7. 9 Identify site monitoring needs.

10 Identify communication and education messages. 11 Compile the ecological character description. 12 Prepare or update the Ramsar Information Sheet (not applicable).

1.4 Policy framework

There are numerous treaties, national and state legislation and regulations that are relevant, and these include the following.

International treaties

Japan–Australia Migratory Bird Agreement (JAMBA, 1974) is a bilateral agreement between the Australian Government and the Government of Japan that requires both parties to protect and conserve habitats important to the conservation of migratory birds and to cooperate with regards to the protection of threatened birds.

China–Australia Migratory Bird Agreement (CAMBA, 1986) is a bilateral agreement between the Australian Government and the People’s Republic of China that requires both parties to protect and conserve habitats important to the conservation of migratory birds.

Republic of Korea – Australia Migratory Bird Agreement (ROKAMBA) is a bilateral agreement between the Australian Government and the Republic of Korea commencing in 2007 that requires both parties to protect and conserve migratory bird species.

Convention on the Conservation of Migratory Species of Wild Animals (Bonn Convention, 1983) is an agreement that obliges countries to cooperate to prevent any species with a distribution within their jurisdiction from becoming endangered. Australia’s obligations under this treaty mostly refer to migratory bird species.

National legislation

Environment Protection and Biodiversity Conservation Act 1999 (EPBC Act): This is the Australian Government’s major legal framework governing the management and protection of Australia’s environment. The objectives of the EPBC Act include the protection of the environment on matters of national significance, conservation of Australian biodiversity, protection and management of significant natural and cultural places, control of movement of plants, wildlife and wildlife derived products, and promotion of ecologically sustainable development.

Australian Heritage Council Act 2003: This Act guides the actions of the Australian Heritage Council whose role is to advise the Australian Government on heritage matters and to maintain the Register of the National Estate.

Water Act 2007: This Act makes provision for the management of the water resources of the Murray–Darling Basin, to ensure that these water resources are managed in an integrated and sustainable way.and to make provision for other matters of national interest in relation to water and water information.


NSW State legislation

Aboriginal Land Rights Act 1983: This Act allows for the return to Aboriginal people of vacant crown land not required for essential or residential purposes.

Catchment Management Act 1989: This presents a framework for catchment management allowing for greater community involvement in particular.

Contaminated Land Management Act 1997: This Act legislates for the investigation and remediation of polluted land and water on contaminated sites.

Crown Lands Act 1989: This Act governs the ownership and management of crown land.

Environment Planning and Assessment Act 1979: This Act provides a framework for environmental impact assessments and the development of policies and plans. In the lower Lachlan, particular consideration is to be given to impacts of developments on the ecological community which is listed as an endangered ecological community (EEC) under the Fisheries Management Act 1994.

Fisheries Management Act 1994: This Act aims to conserve and promote the ecologically sustainable use of the state’s fisheries. The listing under this Act of the lower Lachlan aquatic community as an EEC has considerable legal implications including penalties (up to a $220,000 fine and/or up to two years imprisonment) for harming species or causing damage (e.g. dredging riverbeds or constructing in-stream or floodplain barriers to fish passage) without appropriate authorisation.

Heritage Act 1977: This act affords protection to natural heritage features.

Local Government Act 1993: This specifies approval requirements for building, waste management, and sewerage and stormwater drainage.

Mining Act 1992: This provides a framework for the responsible development, management and use of mineral resources.

National Parks and Wildlife Act 1974: This Act protects all areas reserved as national parks, historic sites, nature reserves, Aboriginal areas, state recreation areas and regional parks as well as all native birds, reptiles, amphibians and mammals (except the dingo) in NSW.

Native Vegetation Management Act 2003: This Act allows for the management of native vegetation clearing through the development consent and planning process. Vegetation clearing may be permitted under authorised property vegetation plans approved under the Act. Clearing that constitutes a routine agricultural management activity or certain routine farming practices (other than clearing) may also be permitted.

Noxious Weeds Act 1993: This outlines landholder responsibilities for the control of noxious weeds and licence requirements for the use of herbicides.

Protection of the Environment Administration Act 1991: This Act affords protection and the capacity to restore and enhance the general quality of the environment in NSW through the principles of ecologically sustainable development.

Protection of the Environment Operations Act 1997: This outlines the requirements for licensing of activities that pollute water and the penalties for unlicensed pollution.


Soil Conservation Act 1938: This Act provides for the conservation of soil resources and farm water resources and for the mitigation of erosion.

Threatened Species Conservation Act 1995 (TSC Act): This Act provides a framework for the classification and protection of endangered species and critical habitats. Numerous species in the Yanga National Park are listed in the schedules of this Act.

Water Management Act 2000: This is the central state legislation governing the development, management and use of water resources throughout NSW.

Water Sharing Plan for the Murrumbidgee Regulated River Water Source 2003: A statutory water sharing plan developed under the provisions of the Water Management Act 2000 (DSNR 2003).

NSW State policy

NSW Fisheries Policy and Guidelines – Aquatic Habitat Management and Fish Conservation (1999): This gives background on fish habitats and resources and identifies activities impacting on aquatic habitats, compliance activities, guidelines for mitigating impacts, conservation and environmental assessment.

NSW Groundwater Policy Framework (1997), NSW Groundwater Dependent Ecosystems Framework (2002) and NSW Groundwater Quality Policy (1998): These documents provide a framework for the improved management of groundwater resources in NSW.

NSW Salinity Strategy (2000): The state policy to reduce the occurrence and impacts of salinity in NSW.

NSW State Rivers and Estuaries Policy (1993): This policy provides for the improvement in management of rivers and their floodplains through principles of sustainable management.

NSW Water Conservation Strategy (2000): This outlines strategies to promote the conservation of water resources in NSW.

NSW Weirs Policy (1997): This allows for the reduction and remediation of environmental impacts of weirs.

NSW Wetlands Management Policy (1996): This is the state policy on the management of wetlands and overseen by the NSW State Wetland Action Group.

Local Environmental Control Plans and Development Control Plans: These control local development and activities permitted in wetlands.


2 Overview of Yanga National Park

2.1 Site location and its catchment

2.1.1 Site location and boundary

Yanga National Park lies less than two kilometres east of the township of Balranald on the south bank of the Murrumbidgee River (Figure 3). The park has about 150 km Murrumbidgee River frontage running north-east to south-west from downstream of the confluence of the Lachlan and Murrumbidgee rivers to Balranald Weir. The national park includes: � four significant lakes – Yanga Lake, Tala Lake, Piggery Lake, and Irrigation Lake � extensive river red gum forest along the Murrumbidgee River (south) � black box (Eucalyptus largiflorens) and lignum (Muehlenbeckia florulenta) woodland

along the Sturt Highway � hundreds of waterways including canals and creeks (e.g. Uara Creek).

2.1.2 Murrumbidgee catchment

The Murrumbidgee catchment is the fourth largest in the Murray–Darling Basin, draining an area of over 84,000 km2 (Figure 4). The catchment consists of 6 749 km of streams (Norris et al. 2002), of which around 1500 km are the main channel of the Murrumbidgee River. The Murrumbidgee River starts in the Fiery Range of the Snowy Mountains, 1600 m above sea level, and flows into the Murray River at Boundary Bend at an altitude of 60 m.

There are more than half a million people living in the Murrumbidgee catchment. Australia's capital, Canberra, with a population of 314,000 and NSW's largest inland city, and Wagga Wagga, with a population of 57,000, are both situated within the catchment (Murrumbidgee CMA 2006). Other major urban centres in the catchment include Balranald, Coleambally, Cooma, Cootamundra, Griffith, Gundagai, Hay, Henty, Junee, Leeton, Narrandera, Queanbeyan, Yass and Tumut.

Agricultural production in the Murrumbidgee catchment is worth in excess of $1.9 billion a year, more than 16% of Australia’s total agricultural production (DSNR 2003). The agricultural industry, with more than 10,000 km of irrigation channels (Khan et al. 2004), provides 25% of NSW fruit and vegetable production, 42% of the state’s grapes and half of Australia's rice production. Other major industries in the catchment include dryland agriculture, including beef production, intensive poultry production, sheep and wool, cropping and softwood plantations (RRDB 2004).

The Murrumbidgee catchment has one of the most diverse climates in NSW, varying from the cooler high alpine in the east to the hot plains of the west. Its annual rainfall varies from more than 1500 mm in the high country to less than 400 mm on the western plains. The annual evaporation averages about 1000 mm to 1800 mm, respectively. Under average climatic conditions about 24% of the rainfall in the 28,000 km2 river catchment above Wagga Wagga appears as runoff, contributing the majority of the river flow. Below Wagga Wagga, the runoff coefficient is less than 2% (Khan et al. 2004).

Under natural conditions the river flows have a very strong seasonal pattern, with peak winter and spring flows driven by the reliable winter and spring rainfall and snow melt from the Great Dividing Range, and low flows in summer (Kingsford and Thomas 2001). The natural yearly flows in the Murrumbidgee average about 3800 GL, two thirds of that in the five months from June to October (Murrumbidgee CMA 2006).


Figure 3: Yanga National Park and the main waterways


The Murrumbidgee River is a highly regulated system and has 14 dams and 8 large weirs on its main course. The large dams include Burrinjuck Dam near Yass, with a capacity of 1026 GL, and Blowering Dam near Tumut, holding 1628 GL. These dams control water for the Murrumbidgee Irrigation Area (MIA) and the Coleambally Irrigation Area situated in the lower Murrumbidgee catchment (Murrumbidgee CMA 2006).

The majority of land use in Murrumbidgee catchment is agricultural production, including cropping and grazing (Table 2; Figure 4). Approximately 10% of the catchment is managed for conservation, including national parks, nature reserves and forest reserves.

Figure 4: The Murrumbidgee catchment and main land use

Table 2: Major land use in the Murrumbidgee catchment

Land use Area (ha) Percentage ACT 235,743 2.89 Cropping 25,042 0.31Cropping and grazing 2,467,162 30.28 Flood irrigation 439,350 5.39 Forestry and forest reserves 247,025 3.03 Grazing native/improved pasture 3,992,705 49.01 Horticulture 13,877 0.17Limited grazing 367,496 4.51 Nature conservation and recreation 311,345 3.82Urban 1353 0.02Vacant 22,807 0.28Water storage/lakes 23,356 0.29Total 8,147,261 100

Source: OEH


2.2 Climate

Climate in Yanga National Park is classified as warm persistently dry grassland based on a modified Köppen classification system.1 The area has a semi-arid climate with low rainfall and hot summers.

Climatic data are recorded at a number of sites within the Murrumbidgee catchment. The nearest weather station is at Balranald, run by the Bureau of Meteorology (site no. 049002). The following information is extracted from 1889 to 2006 data. The average annual rainfall is about 320 mm. The average monthly rainfall distribution at Balranald is given in Figure 5 and other average monthly weather parameters – radiation and evaporation, maximum and minimum temperatures – are given in Figure 6 and Figure 7, respectively. Note that data are missing for some years.

Evaporation is an important factor in the water cycle of temperate climate regions, with high values in the summer months (daily average 7.44 mm) and lower values in winter months (daily average 2.54 mm). Mean monthly evaporation exceeds monthly rainfall throughout the year (by a factor of 10 or more during summer months).

Mean Monthly Rainfall at Balranald (BOM site No 049002)

15

17

19

21

23

25

27

29

31

33

Jan Feb Mar Apr May Jun Jul Aug Sep Oct Nov DecMonth

Ave

rage

Rai

nfal

l for

119

yea

rs (1

889-

2007

) (m

m)

Data source: Bureau of Meteorology

Figure 5: Monthly rainfall distribution at Balranald, average for 119 years from 1889 to 2006

1 Bureau of Meteorology, www.bom.gov.au/iwk/climate_zones/index.shtml


Mean monthly radiation and evaporation at Balranald

0

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400

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900


Rad

iatio

n (M

J/m

2)

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Evap

orat

ion

(mm

)

Mean Monthly RadiationMean Monthly Evaporation


Figure 6: Mean monthly radiation and evaporation at Balranald, average of 118 years from 1889 to 2006

Mean daily maximum and minimun temperature at Balranald

0

5

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15

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35


Tem

pera

ture

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ree

Mean Daily MaxMean Daily Min


Figure 7: Mean maximum and minimum temperatures at Balranald, average for 118 years from 1889 to 2006


2.3 Geology

The lower Murrumbidgee lies within the eastern Riverine Plains province of the Murray Geological Basin, a large saucer-shaped structure which extends into three states and covers about 300,000 km2 of south-eastern Australia (Lawson and Webb 1998). The Murray Basin consists of a sequence of mostly semi-consolidated to unconsolidated flat lying sedimentary deposits which began accumulating about 50 million years ago. They have a maximum thickness of about 600 m in the central area near Mildura and, within the lower Murrumbidgee, a maximum of about 400 m near Balranald. The maximum thickness at Narrandera, where the Murrumbidgee River enters the Murray Geologic Basin, is about 170 m (Kumar 2002).

In the low salinity area of the lower Murrumbidgee, the sedimentary deposits can be subdivided into three main units or layers. These layers are not actually separate, distinct aquifers. The three layers, in order of youngest (uppermost) to oldest (lowermost) are:� Shepparton Formation � Calivil Formation � Renmark Group.

The Shepparton Formation extends from ground surface down to depths of 50–70 m, and is characterised by yellow and brown poorly sorted sands and clays. The proportion of sand is highly variable but mostly about 10–30%, with most occurring in the top 30 m. These sands are often referred to as ‘shallow aquifers’.

The Calivil Formation was deposited from 15 to 5 million years ago and is dominated by pale grey, coarse quartz sand with lenses of pale grey to white kaolinitic clay. The proportion of sand is typically 50–70%, making it the most productive layer not only within the low salinity area but also the entire eastern Murray Basin. Its thickness is generally 50–70 m. It is this layer (and the upper sand beds of the Renmark Group) that is generally referred to when the term ‘deep aquifer’ is used.

The Renmark Group sediments, which are the oldest deposits in the profile and hence began accumulating about 50 million years ago, are characterised by dark grey to black carbonaceous clay and dark brown lignite (a young form of coal). Coal and lignite deposits generally have significant amounts of sulfur associated with them, and the lignite could be a source of hydrogen sulfide (‘rotten egg gas’) emanating from some bores. The Renmark Group also contains thick sequences of grey, medium grained quartz sand which commonly comprises 30–50% of the entire unit. Many production bores extend into, and obtain groundwater from, Renmark Group sands. The Renmark Group thickness varies considerably in relation to the underlying bedrock surface, but has a maximum thickness of about 280 m in the lower Murrumbidgee low salinity area (Kumar 2002).


2.4 Landform

Six soil landscapes occur in Yanga National Park (Walker 1991; Figure 8). Description of the six landforms and associated vegetation is given in Table 3.

2.5 Land tenure

The site is crown land dedicated as a national park under the NPW Act. Surrounding lands are primarily freehold. Before it was purchased by the Department of Environment and Conservation NSW (DEC) in 2005, the site was mostly freehold except for the 1932 ha of crown land of Yanga Nature Reserve.

2.5.1 Land use before dedication as a national park

Before being purchased by DEC, the majority (over 90%) of the land was used for grazing (Table 4; Figure 9).

Table 3: Description of soil landscapes in Yanga Nation Park

Landscape Description of soils and vegetation Riverland Plains with grey cracking and non-cracking clays, levees with texture-contrast

soils, lunettes of deep calcareous sands; sparse to moderate river red gum, black box and river cooba along channels and in bends; moderate to dense lignum and nitre goosefoot; abundant grasses and forbs.

Lowbidgee Plains with yellow-grey cracking clays, isolated brown and red texture-contrast soils; sandy solonised brown soils on prior streams; dense lignum, scattered bladder saltbush and cotton bush; depressions with canegrass and Dillon bush; isolated to clumped bluebushes; abundant forbs throughout.

Murrumbidgee Plains with grey cracking and non-cracking clays; lunettes and rises of deep brownish sands; backplains of scalded yellow texture-contrast soils; moderate to dense black box, lignum, old man saltbush and nitre goosefoot; rises, lunettes and backplains with clumped mallee, white cypress pine, prickly wattle and scattered shrubs; abundant forbs and grasses.

Yanga Loamy to sandy solonised brown soils and red texture-contrast soils; scattered belah, white cypress pine and mallee; scattered Dillon bush; abundant annuals.

Victoria Lake beds, margins and channels of grey cracking clays and brownish sands; lunettes of deep, cemented sands; scattered to dense black box, lignum and nitre goosefoot along margins and channels; sparse prickly wattle and bluebushes on lunettes; copperburrs, forbs and annual grasses.

Marma Levees of red and yellow texture-contrast soils and grey cracking clays; sandplains and lunettes of solonised brown soils and red texture-contrast soils; floodplains of grey cracking clays; scattered to dense bluebushes, bladder saltbush and old man saltbush; canegrass in swamps; abundant forbs, copperburrs and annual saltbushes.


Reproduced from Walker (1991)

Figure 8: Soil landscape in Lowbidgee


Table 4: Detailed land use in Yanga National Park before purchase by DEC

Land use type Area (ha) Area (%)

Conservation area – National Park 1932.32 3.89 Cropping – continuous or rotation 238.65 0.48 Cropping – within controlled flood system 0.64 0.00 Cropping irrigated – rice 145.77 0.29 Grazing – irrigated pastures 381.28 0.77 Grazing – volunteer and naturalised and native or improved pastures 24,011.35 48.39 Grazing – volunteer and naturalised and native or improved pastures – with fixed irrigation system not used at the time of mapping 626.39 1.26 Grazing – wide road reserve or travelling stock route and with some grazing 24.87 0.05 Grazing – within controlled flood system (evidence of previous cropping) 1010.04 2.04 Grazing within bed of an ephemeral lake (evidence of previous cropping) 178.30 0.36 Low level forestry production and grazing 18,924.43 38.14 River and drainage system – flood chute 22.70 0.05 River and drainage system – flood or irrigation structure 0.12 0.00 River and drainage system – irrigation supply channel 13.02 0.03 River and drainage system – river and creek or other incised drainage feature 411.99 0.83 River and drainage system – waterway associated with controlled flooding/opportunistic cropping systems 43.64 0.09 Transport and other corridors – road or road reserve 23.12 0.05 Tree cover – native forest 182.99 0.37 Water body – reservoir 1130.78 2.28 Wetland – floodplain swamp – backswamp 196.33 0.40 Wetland – floodplain swamp – billabong 15.36 0.03 Wetland – swamp 104.41 0.21 Total 49,618.49 100.00

Data source: ABARES, http://adl.brs.gov.au/mapserv/landuse/


Data source: ABARES, http://adl.brs.gov.au/mapserv/landuse/ Areas marked ‘no data’ are mostly grazing land, and are not included in Table 4.

Figure 9: Land use in Yanga National Park before dedication as a national park


2.6 Wetland types within Yanga National Park Yanga National Park covers an area of 66,743 ha and incorporates 12 different wetland types according to the Ramsar Convention classification system (Table 5) as a mosaic of permanent lakes and ponds to seasonal inundated woodland variously interconnected across time (driven by hydrology) and space (determined by geomorphology).

According to the wetland classification system adopted by the ANZECC Wetlands Network (now known as the ANZECC Wetlands and Migratory Shorebirds Taskforce), which was modified from the Ramsar Convention classification system to suit the Australian situation, Environment Australia identified 10 types of wetland occurring within the Lowbidgee Floodplain (EA 2001). All 10 types occur in Yanga National Park.

Inland wetlands 1 Permanent rivers and streams: includes waterfalls. 2 Seasonal and irregular rivers and streams. 3 Riverine floodplains: includes river flats, flooded river basins, seasonally flooded

grassland, savanna and palm savanna. 4 Seasonal/intermittent freshwater lakes (>8 ha), floodplain lakes. 5 Permanent freshwater ponds (<8 ha), marshes and swamps on inorganic soils, with

emergent vegetation waterlogged for at least most of the growing season. 6 Seasonal/intermittent freshwater ponds and marshes on inorganic soils: includes

sloughs, potholes; seasonally flooded meadows, sedge marshes. 7 Shrub swamps; shrub-dominated freshwater marsh, shrub carr, alder thicket on

inorganic soils. 8 Freshwater swamp forest; seasonally flooded forest, wooded swamps; on inorganic

soils.

Human-made wetlands 1 Water storage areas; reservoirs, barrages, hydro-electric dams, impoundments

(generally >8 ha).2 Irrigated land and irrigation channels: rice fields, canals, ditches.

2.7 Ecosystem services When listed as nationally important wetlands (code NSW021) in 2000, the Lowbidgee floodplain met five of the seven selection criteria (EA 2001). Brief justifications for each of these criteria are given below. 1 It is a good example of a wetland type in a biogeographic region in Australia. 2 As mentioned before, there are 12 (10 according to Environment Australia) wetland

types in Yanga National Park. The dominant wetland type, river red gum forest (tree-dominated freshwater wetlands) is one of the largest stands in Australia (AHC 1998). Other significant wetlands include Yanga Lake, Piggery Swamp, and seasonal flooded lignum woodland.

3 It is a wetland which plays an important ecological or hydrological role in the natural functioning of a major wetland system/complex. The wetland comprises the floodplain of the lower Murrumbidgee River, including Tala and Yanga lakes. During major floods, the system services as a large water retention basin absorbing the flood peak. Yanga National Park supports a diverse range of native flora and fauna species and vegetation types of biodiversity significance to the NSW Riverina Biogeographic Region.


4 It is a wetland which is important as the habitat for animal taxa at a vulnerable stage in their life cycles, or provides a refuge when adverse conditions such as drought prevail. In the arid and semi-arid inland, periodic drought is a prevailing feature. Yanga National Park has an array of permanent water bodies, including lakes, swamps, creeks and irrigation canals. They provide important drought refuges for biota, especially for waterbirds (Maher 1990; Kingsford and Thomas 2001).

5 The wetland supports 1% or more of the national populations of any native plant or animal taxa.At the time of listing, the Lachlan–Murrumbidgee confluence met the 1% population criterion for two migratory waterbirds: black-winged stilt (Himantopus himantopus)and red-necked avocet (Recurvirostra novaehollandiae) (Smith 1990). Yanga National Park alone may not meet this criterion, as the principal habitat for the two species is flooded cropland along the Pollen/Carira Creek (Maher 1990).

6 The wetland supports native plant or animal taxa or communities which are considered endangered or vulnerable at the national level. Yanga National Park supports the populations of a number of internationally and nationally threatened species included in the global red list of the World Conservation Union (IUCN) or listed under the EPBC Act. There are 12 vulnerable species, all of which are waterbirds, recorded in Yanga National Park over time, such as the Australasian bittern, freckled duck and blue-billed duck. The southern bell frog (Litoria raniformis), which is considered to be endangered at state level, has been recorded in Piggery Swamp, Mercedes Swamp and Twin-bridge Swamp.

Table 5: Wetland types found within Yanga National Park in order of dominance

Ramsar code Description Area

(ha)* Inland wetlands

Xf Freshwater, tree-dominated wetlands; includes freshwater swamp forests, seasonally flooded forests, wooded swamps on inorganic soils >30,000

W Shrub-dominated wetlands; shrub swamps, shrub-dominated freshwater marshes, shrub carr, alder thicket on inorganic soils >10,000

P Seasonal/intermittent freshwater lakes (>8 ha); includes floodplain lakes >1600 M Permanent rivers/streams/creeks; includes waterfalls 411

TpPermanent freshwater marshes/pools; ponds (<8 ha), marshes and swamps on inorganic soils with emergent vegetation waterlogged for at least most of the growing season

<100

N Seasonal/intermittent/irregular rivers/streams/creeks 22

Ts Seasonal/intermittent freshwater marshes/pools on inorganic soils;includes sloughs, potholes, seasonally flooded meadows, sedge marshes >150

Human-made wetlands

4 Seasonally flooded agricultural land (including intensively managed or grazed wet meadow or pasture) 425

3 Irrigated land; includes irrigation channels and rice fields 159

6 Water storage areas; reservoirs/barrages/dams/impoundments (generally >8 ha) 126

9 Canals and drainage channels, ditches 222 ^ Ponds, includes farm ponds, stock ponds, small tanks (generally <8 ha) #* Data sources: NPWS; McCosker (2008) ^ Not listed in EA (2001) # No information, or less than 10 ha


3 Overall conceptual ecological modelAn ecological model is a conceptual or mathematical representation of a natural phenomenon. Ecological models are abstractions or simplifications of the real world that portray the dominant components and key processes. Typically, models define relationships among states (components of the ecosystem) and transitions (processes that change the states). These relationships are the basis on which to predict changes in the ecological character over time depending upon trajectories of, or perturbations to, key processes. Ecological models are excellent tools for generating questions about the system behaviour and guiding decision making for planning and management. In addition, models also document and record major assumptions and current understanding of the system.

Wetland ecosystems are dynamic in space and time, with the given components and processes being primarily determined by the hydrogeologic settings, which are in turn determined by the climate and geomorphology (Figure 10). Climate, through precipitation, evaporation and transpiration, influences surface and groundwater flows and the hydrology and hydrological variability of wetlands. Geomorphology determines the size, shape and location of wetlands within the landscape, and the water sources, physico-chemical properties and soils as well. The natural drivers are strongly affected by human activities on the landscape, such as land use and water diversion, which will be addressed in the section on major threats to the sites (section 8). Following DEWHA (2008), the human interventions and disruptions (referred to as pressures, stressors or levers in some literature, such as Phillips et al. 2005) are treated as system drivers in the model.

The hydrogeologic setting of the landscape is the master variable driving wetland form and function. Hydrogeologic setting is defined by topography, soils, subsurface geology and climate, and drives groundwater and surface water movement patterns. The formation, distribution, and biogeochemistry of individual wetlands are based on the interaction between these groundwater and surface water movement patterns and climate.

Models of critical processes, such as hydrological regimes and nutrient cycling, will be developed and presented in section 6 when describing those processes.


Modified from Wetlands and Waterbirds Taskforce (2007).

Feedback from biota to their environment and interactions among biological communities were omitted from the model for simplicity.

D = Driver, C = Component, P = Process.

Figure 10: Overall ecological conceptual model for Yanga National Park

Management (D)EWAs



Climate (D)Rainfall





Aquifers





Wetland Ecosystem










NutrientsTurbidity

Water quality






Amphibians



Invertebrates



Cultural

Decomposers (C)

Fungi

Bacteria

Management (D)EWAs



Climate (D)Rainfall





Aquifers





Wetland Ecosystem










NutrientsTurbidity

Water quality






Amphibians



Invertebrates



Cultural

Decomposers (C)

Fungi

Bacteria


4 Ecological services and benefits The ecosystem services that support the ecological character of Yanga National Park have been described below in detail. These services are closely related. A summary of selected services, their condition and trend are shown in Table 6, which adapted the classification system of the Millennium Ecosystem Assessment (MEA 2005).

4.1 Regulating services

4.1.1 Maintaining regional water quality

Yanga National Park lies at the downstream end of the Lowbidgee floodplain, which is characterised by meandering channels and wide floodplains. The land is generally flat to gently sloping and vegetated. During floods, up to 85% of the water in the Murrumbidgee River flows through the floodplain (DWR 1991). As water flows through the floodplain, the system effectively retains, recycles and removes suspended solids, organic and inorganic nutrients, and other pollutants from the water through several mechanisms, including (Sather and Smith 1984, cited by Mitsch and Gosselink 2000): � a reduction in water velocity favouring sedimentation � a variety of anaerobic and aerobic processes promoting denitrification, chemical

precipitation, and other chemical reactions that remove certain chemicals from water � a high rate of productivity that leads to high rates of mineral uptake by vegetation and

subsequent burial in sediments when plants die � a diversity of decomposers and decomposition process in sediments � a large contact surface of water with sediment because of the water’s shallowness,

leading to significant sediment–water exchange � an accumulation of organic peat that causes the permanent burial of chemicals.

Currently, there are no data to quantify this service.

4.1.2 Replenish groundwater

In general, the shallow aquifers (e.g. Upper Shepparton Formation aquifer) underlying the floodplain are continually being recharged by rainwater that infiltrates the ground, by floods, by interconnected water bodies, and by leakage from nearby aquifers (Figure 11). The critical components in maintaining the level of groundwater recharge are indicated below. However, there is no quantitative information on the relationship between groundwater recharge and the components that maintain the service.

As mentioned in section 2.2, the mean annual rainfall and evaporation is 320 mm and 1814 mm, respectively. In such a dry environment, the recharge from rainwater to replenish groundwater is minimal. In the semi-arid lower Murray–Darling region, recharge from rainwater is generally less than 1 mm/yr (DIPNR 2003).

The major groundwater recharging corresponds to floods. During floods, the over-bank flows are retained by an array of land features in the floodplain, including ephemeral wetlands (e.g. Lake Yanga and Piggery Lake), creeks (e.g. Uara Creek), irrigation storages and depressions. The retained floodwater provides the major water input which percolates to aquifers.


Table 6: Ecosystem benefits and services

MEAcategory Ecosystem service Ramsar

criteria Condition

Maintain regional water quality 1 Losing Replenish groundwater 1 Declining Flood control 1 Maintained

Regulating

Regulate climate 1 Declining Provides a combination of wetland types and habitats 1 Losing Support populations of biota species for maintaining the

biodiversity of the NSW Riverina Bioregion Support 20 threatened faunal species Support four threatened flora species Support at least one threatened fish species Support three endangered ecological communities Supporting eleven migratory bird species protected by

international agreements

3

2, 3, 4 3, 4 3, 4 3,43,4

Declining

Provide an important source of food, spawning ground and nursery for fishes

8 Declining

Supports large stands of primary producers 1, 8 Declining

Supporting

Provide drought refuge for waterbirds and other fauna 4 Losing Aboriginal heritage Sustained European historical sites Sustained Recreation and tourism: camping, touring, bushwalking Increasing

Culturalservices

Nature observation, research site for ecology, natural resources, biodiversity conservation

Increasing

Modified from Jolly and Walker (1995)

Figure 11: Schematic of the conceptual model for groundwater, illustrating the major recharge areas in the floodplain


In a study of the irrigation and groundwater interactions in the MIA, Khan et al. (2004) found that hydrographs of groundwater piezometers showed a cyclic response indicating a periodic recharge and discharge during the irrigation and non-irrigation periods. The irrigation practices (e.g. irrigated pasture, rice paddy) within the national park and adjacent areas would have similar effects on the groundwater.

Vegetation cover is unlikely to influence the rate of recharge significantly as most recharge occurs when excess water is available during floods. However, transpiration by river red gums is thought to be a factor in maintaining lower groundwater levels in the Upper Shepparton Formation in semi-arid regions (such as Yanga National Park) relative to those in the aquifer in adjacent cleared dryland and irrigation areas (Thorburn and Walker 1994). River red gums have some roots (‘sinkers’) that penetrate more than 10 m into the subsoil to reach sandy aquifers (Bacon et al. 1993). A significant change in river red gum distribution is unlikely unless there are major bush fires. It is suggested that it is more appropriate to continuously monitor groundwater tables in the river red gum forest and adjacent areas than to monitor groundwater recharge or the components that maintain this service. A change in the ecological character for this service would be signalled by a significant change in the depth of the water table.

4.1.3 Flood control

The floodplain within Yanga National Park (and the adjacent Lowbidgee Irrigation District) acts as a large water retention basin, intercepting storm runoff and storing storm water, thereby changing the sharp runoff peaks to slower discharges over a longer period of time (Figure 12). For example, Yanga Lake has a capacity of around 6 GL(R Hampton 2008, pers. comm.). Because it is the peak flows that usually produce flood damage, the effect of the floodplain system is to reduce the danger of flooding.

4.1.4 Regulate climate

Yanga National Park is most likely to influence the local and global climate through land cover and biologically mediated processes, for instance, carbon sequestration. However, there does not appear to be sufficient data and a generally accepted method to quantify this service.

Storm

Time

Flow R

ate

Wetlands

Without Wetlands

Storm

Time

Flow R

ate

Wetlands

Without Wetlands

Source: Kusler (1983)

Figure 12: The effect of wetlands on peak stormwater flows


4.2 Supporting services

4.2.1 Provides a combination of wetland types, which is typical in the NSW Riverina Bioregion

The NSW Riverina Bioregion lies in south-west NSW, extending into central northern Victoria. The bioregion is approximately 9,576,964 ha, with 7,090,008 ha or 74.03% of it lying in NSW (IBRA 5.1). The NSW portion of the bioregion occupies approximately 8.86% of the state (Eardley 1999; IBRA 5.1).

The Riverina Bioregion extends from Ivanhoe in the Murray–Darling Depression Bioregion south to Bendigo, and from Narrandera in the east to Balranald in the west. Major towns within the boundaries include Hay, Coleambally, Deniliquin, Leeton, Mossgiel, Hillston, Booligal, Balranald and Wentworth. The bioregion also includes outlying remnants of the Murray–Darling Depression Bioregion on its western boundary, and the Victorian Midlands Bioregion in the south.

The Murray and Murrumbidgee rivers and their major tributaries, the Lachlan and Goulburn rivers, flow from the highlands in the east, westward across the Riverina plain.

Yanga National Park is part of the Murrumbidgee–Lachlan confluence, one of eight wetland systems identified as having bioregional significance in the Riverina (NLWRA 2002). Prior to 2000, the wetlands of the Riverina Bioregion were described as being in fair to degraded condition (NLWRA 2002). Changed hydrology is a key threat to all of these wetlands, but there are also impacts from feral animals, exotic weeds, water extraction, regulation and diversion, altered nutrient levels, salinity, grazing pressure, reduced flows and water storage use. As a newly gazetted national park, a wide range of measures aiming to preserve and enhance the area for nature conservation have been commenced, including the preparation of a management plan.

Wetland types in Yanga National Park include freshwater forested wetlands, shrub swamps and seasonal marshes (Table 5).

4.2.2 Supports biota species that maintain biodiversity of the NSW Riverina Bioregion

Yanga National Park is one of the most biologically diverse areas in the NSW Riverina Bioregion, especially for avifauna (nearly 60% of birds recorded in the NSW Riverina Bioregion can be found in Yanga National Park: Table 7; Appendix 2). The site’s rich natural heritage – landforms and substrate types, animal and fish habitat, vegetation cover and distribution, faunal and floral species – provides the basis for maintaining the biodiversity of the bioregion, and the state’s economy and standard of living.

The floodplain, characterised by vegetation mosaics changing from high ground saltbush (Atriplex nummularia) shrubland and prickly wattle (Acacia victoriae)woodland, to black box woodland, river red gum forest and aquatic marshes, hosts more than 300 vascular plant species (Appendix 1). The diverse range of vegetation provides habitat for various animals. There are 269 fauna species (excluding fish) reported from Yanga National Park – these would contribute significantly to the biological diversity of the NSW Riverina Bioregion (see section 5.3.3 for fish species). Of these 269 species, 210 are birds (Appendix 2), 11 are amphibians, 24 are mammals (of which nine are introduced species), and 24 are reptiles (Table 7; species lists in sections 5.3.4, 5.3.5 and 5.3.6).


Table 7: Fauna and flora records in Yanga National Park and the NSW Riverina Bioregion

Group Riverina NSW Yanga National Park Occurrence (%)

Bird 362 210 58.0

Mammal 89 25 27.0

Reptile 86 24 27.9

Amphibian 27 11 40.7

Plant 1,894 303 16.0

Fish* 18

Data sources: Pressey et al. (1984); Maher (1990); Robertson et al. (1994); Bales (1999); Atlas of NSW Wildlife; Spencer and Allman (2008); Wassens et al. (2008a)

* Including the Murrumbidgee channel. Data source: Baumgartner (2004). No fish species are recorded in the Atlas of NSW Wildlife for NSW Riverina Bioregion.

4.2.3 Supports two endangered ecological communities

There are two ecological communities within Yanga National Park which are listed as endangered under the TSC Act: Myall woodland, and an aquatic ecological community in the natural drainage system of the lower Murray River catchment.

Aquatic ecological community in the natural drainage system of the lower Murray River catchment

The lower Murray ecological community includes all native fish and aquatic invertebrates within all natural creeks, rivers and associated lagoons, billabongs and lakes of the regulated portions of the Murray River below the Hume Weir, the Murrumbidgee River below Burrinjuck Dam, and the Tumut River below Blowering Dam, as well as all their tributaries and branches (Fisheries Scientific Committee 2001). These tributaries and branches include Billabong Creek, Yanco Creek, Colombo Creek and their tributaries, the Edward River and the Wakool River and their tributaries, Frenchmans Creek, the Rufus River and Lake Victoria. Excluded from the definition are the Lachlan River and the Darling River and their tributaries. Artificial canals, water distribution and drainage works, farm dams and off-stream reservoirs are also excluded. The community includes 23 native fish species and over 400 recorded native invertebrate species.

In Yanga National Park, diverse habitats accommodate this EEC (Figure 13), including permanent and intermittent river channels, intermittent swamps, and billabongs. The modification of natural river flows as a result of river regulation (dams, weirs) was identified as the main threat to this EEC. The changed river flow regimes lead to reduced habitat quality, loss of spawning cues, and reduced opportunities for dispersal and migration. Grazing also contributes to the degradation; however, the exclusion of livestock after gazettal as a national park should ease this pressure.


Photo: L Wen/OEH

Figure 13: Twin-bridges Swamp, a freshwater wetland in Yanga National Park, which accommodates the threatened aquatic ecological community including the southern bell frog

Myall woodland in the Darling Riverine Plains, Brigalow Belt South, Cobar Peneplain, Murray–Darling Depression, Riverina and South Western Slopes bioregions

This ecological community is scattered across the eastern parts of the alluvial plains of the Murray–Darling River system. Typically, it occurs on red-brown earths and heavy textured grey and brown alluvial soils within a climatic belt receiving between 375 and 500 mm mean annual rainfall. The structure of the community varies from low woodland and low open woodland to low sparse woodland or open shrubland, depending on site quality and disturbance history. The tree layer grows up to a height of about 10 m and invariably includes weeping myall or boree (Acacia pendula) as one of the dominant species or the only tree species present. The understorey includes an open layer of chenopod shrubs and other woody plant species and an open to continuous groundcover of grasses and herbs (NSW Scientific Committee 2005).

There are currently about 30 ha of Myall woodland in Yanga National Park (McCosker 2008) located north of Yanga Lake. While land clearing and overgrazing by feral and domestic animals were the major threats prior to 2005, grazing by rabbits is an ongoing risk to the community.


4.2.4 Supports 21 threatened fauna species

Historically, 21 endangered or vulnerable fauna have been recorded within Yanga National Park and in its vicinity (Table 8). The endangered species include three birds, one amphibian and one reptile, while the vulnerable species include 14 birds and two mammals. One waterbird species, the little bittern (Ixobrychus minutus), is not included in Table 8 because it is not listed as threatened in the EPBC Act or TSC Act. However, it is listed as threatened in the Victorian Flora and Fauna Guarantee Act 1988 and as endangered in the Advisory list of threatened vertebrate fauna in Victoria – 2007(DSE 2007).

The threatened square-tailed kite (Lophoictinia isura) was recorded in 1989/1990 and 2005/2006 waterbird surveys (Maher 1990, 2006), and on a number of other occasions (Atlas of NSW Wildlife). The species breeds in south-western Australia and in wetter parts of southern and eastern Australia, with birds from southern Australia probably overwintering in the tropics (Debus 1983; Blakers et al. 1984; Debus and Silveira 1989; Johnstone and Storr 1998). Square-tailed kites require a large area of open forest to support a single pair as they feed mainly on nestling birds and eggs (Barnes et al. 1999), and appear to prefer a landscape that is structurally diverse (Debus and Czechura 1989). The diverse vegetation types ranging from river red gum forest, black box woodland and old man saltbush shrubland in Yanga National Park (section 5.3.1) provide a regular breeding habitat for the species.

It should be pointed out that there are only a few systematic fauna surveys in Yanga National Park, especially for nocturnal species; therefore it is highly possible that other threatened species occupy the park. For example, three bat species – inland forest bat (Vespadelus baverstocki), little pied bat (Chalinolobus picatus) and large-footed myotis (Myotis adversus) – are known to be associated with inland riverine forests and freshwater wetlands in the Murrumbidgee catchment (Churchill 1998). Although there are no records in the Atlas of NSW Wildlife for Yanga National Park, it is likely that the three threatened species inhabit the park.

The loss, fragmentation and degradation of habitats were identified as major threats for a majority of the species listed by the NSW Scientific Committee. Yanga National Park contains suitable breeding, nursing, and foraging/hunting habitats that can support the persistence of those threatened species.

4.2.5 Supports four endangered and vulnerable plant species

Two endangered and two vulnerable flora species were recorded in Yanga National Park (Table 9). The austral pipewort (Eriocaulon australasicum) was last seen in 1853. The other three species were recorded recently (1990s). Thirteen threatened plant species are known or predicted to occur in the lower Murrumbidgee region, such as lanky buttons (Leptorhynchos orientalis) and silky swainson-pea (Swainsona sericea).2As there has been no systematic flora survey in Yanga National Park, more threatened flora species are likely to occur in the park.

2 www.threatenedspecies.environment.nsw.gov.au


Table 8: Endangered and vulnerable fauna found within Yanga National Park

Class Family Scientific name Common name Legal status Last sighting

Amphibian Hylidae Litoria raniformis Southern bell frog E January 2009 Aves Acanthizidae Pyrrholaemus

brunneus Redthroat V 18/09/1991

Accipitridae Lophoictinia isura Square-tailed kite V 22/12/2005 Anatidae Oxyura australis Blue-billed duck V 21/12/2005

Stictonetta naevosa Freckled duck V 22/12/2005 Anseranatidae Anseranas

semipalmata Magpie goose V 19/11/1989

Ardeidae Botaurus poiciloptilus Australasian bittern

V 12/01/2006

Burhinidae Burhinus grallarius Bush stone-curlew

E 31/12/1981

Cacatuidae Cacatua leadbeateri Major Mitchell's cockatoo

V 20/10/2000

Climacteridae Climacteris picumnus Browntreecreeper

V 22/01/2008

Eupetidae Cinclosoma castanotus Chestnut quail-thrush

V 31/12/1981

Meliphagidae Grantiella picta Paintedhoneyeater

V 1/02/1997

Petroicidae Melanodryas cucullata Hooded robin V November 1998 Pomatostomidae Pomatostomus

temporalis temporalis Grey-crowned babbler

V December 2005

Psittacidae Polytelis anthopeplus monarchoides

Regent parrot (eastern subsp.)

E 1/02/1997

Polytelis swainsonii Superb parrot V 7/11/1977 Rostratulidae Rostratula

benghalensis australis Painted snipe E 10/01/1990

Strigidae Ninox connivens Barking owl V 31/12/1981 Mammalia Dasyuridae Dasyurus maculatus Spotted-tailed

quoll V 30/06/2004

Vespertilionidae Myotis Macropus Large-footed bat V March 2009 Reptilia Elapidae Echiopsis curta Bardick E 31/12/1974

E = Endangered, V = Vulnerable. Data sources: Bales (1999); Maher (1990, 2006); Atlas of NSW Wildlife; Spenser and Allman (2008); M Pennay (2009, pers. comm.)

Table 9: Endangered and vulnerable plant species found in Yanga National Park

Family Scientific name Common name Status Sightings Eriocaulaceae Eriocaulon

australasicum Austral pipewort E 1

Brassicaceae Lepidium monoplocoides Winged peppercress E 1 Solanaceae Solanum karsense Menindee nightshade V 1 Fabaceae/Faboideae Swainsona murrayana Slender darling pea V 1

Data source: Atlas of NSW Wildlife


4.2.6 Supports at least one threatened fish species

Historically, four threatened fish species – Murray hardyhead (Craterocephalusfluviatilis), silver perch (Bidyanus bidyanus), olive perchlet (Ambassis agassizii) and southern purple-spotted gudgeon (Mogurnda adspersa) – are known to occur in the lower Murrumbidgee (Gilligan 2005). However, a catchment-scale fish survey (Gilligan 2005) and river reach scale survey (Baumgartner 2004) only detected silver perch. Gilligan (2005) concluded that the other three species were likely to be extinct locally.

4.2.7 Supports an abundance of waterbirds

In the past the Lowbidgee has regularly supported more than 50,000 waterbirds, and sometimes more than 100,000, including some of the largest breeding colonies of straw-necked ibis (Threskiornis spinicollis) in Australia (DWR 1994). In the wet year of 1983, the swamps in the Lowbidgee supported more than 100,000 waterbirds (Kingsford and Thomas 2001). The most abundant species include grey teal (Anasgracilis), pink-eared duck (Malacorhynchus membranaceus) and Eurasian coot (Fulicaatra) (Pressey et al. 1984).

Floodplain wetlands within Yanga National Park, including riparian river red gum forests, vegetated swamps (such as Shaw’s Swamp, Breer, Twin-bridges, Narkungerie) and open water lakes (Tala Lake, Yanga Lake, Piggery Lake), creeks (Monkem Creek, Uara Creek), historically support large numbers of waterbird colonies. A comprehensive waterbird survey in the Lachlan–Murrumbidgee confluence in 1989–90 covered nine significant wetlands in Yanga National Park (Maher 1990). The survey recorded a total of 61 waterbird species. Most of these species were found in Yanga National Park. Those of national, state and regional importance are listed in Table 10.

Maher (1990) identified four wetlands as important breeding areas for colonial nesting and other waterbirds – Tarwillie Swamp, Shaw’s Swamp, Piggery Lake and Waugorah Creek – where large numbers of nests were located (Figure 14). For example, at Shaw’s Swamp, 500 little pied cormorant (Phalacrocorax melanoleucos) nests were recorded. In Tarwillie Swamp, 800 little pied cormorant, 400 little black cormorant and 200 great egret nests were recorded. Particularly important are the river red gum forests, which are the traditional nesting habitat for egrets in south-eastern Australia, and the species shows a reluctance to breed away from these areas (Maher 1990; Briggs et al. 1997).

Important feeding areas in Yanga National Park include Tarwillie Swamp, Shaw’s Swamp, Piggery Lake, Two-Bridge Swamp between Redbank Weir and Lambing Down Hill, and river red gum forests within 10 km of Redbank Weir along the Murrumbidgee River (Figure 14).

A long-term waterbird monitoring program covering the Lowbidgee floodplain is the Aerial Surveys of Waterbirds in Eastern Australia (Kingsford and Porter 2006) managed by the University of NSW and OEH, which started in 1983. The survey produced a series of occasional papers and annual summary reports (Kingsford et al. 2008).

Although not specific for Yanga National Park, these reports indicate that the floodplain supported large numbers of waterbird species and colonial birds, such as egrets, spoonbills and ibis, in the 1980s and early 1990s. However, the survey found that waterbird numbers collapsed by 90%, from an average of 139,939 (1983–86) to 14,170 (1998–2001) in the Lowbidgee (Kingsford and Thomas 2001). Similar declines occurred across all functional groups: piscivores (82%), herbivores (87%), ducks and small grebe species (90%), large wading birds (91%) and small wading birds (95%).


The decline in waterbird populations was evidenced throughout Australia (Kingsford 2003; Kingsford and Thomas 2004; Phillips and Muller 2006; Nebel et al. 2008), and worldwide (Wetland International 2006). For example, between the 1980s and 2006, Nebel et al. (2008) estimated that the mean number of migratory shorebirds declined by 73% while the Australian resident waterbird population fell by 81% in eastern Australia. In this sense, the Lowbidgee floodplain still remains as significant breeding, feeding and nestling habitat contributing to sustaining the waterbird population, especially in inland Australia, regardless of the low numbers of waterbirds recorded recently.

Table 10: Waterbird species of national, state and regional importance recorded in the 1989–90 survey in Yanga National Park

Family name Scientific name Common name Importance levelCircus approximans Swamp harrier State Accipitridae Haliastur sphenurus Whistling kite Regional Anas castanea Chestnut teal Regional Anas gracilis Grey teal State Anas rhynchotis Australasian shoveler State Anas superciliosa Pacific black duck State Aythya australis Hardhead State Biziura lobata Musk duck State Cygnus atratus Black swan State Oxyura australis Blue-billed duck State

Anatidae

Stictonetta naevosa Freckled duck National Anhingidae Anhinga melanogaster Darter State

Ardea alba Great egret National Ardea intermedia Intermediate egret National Ardea pacifica White-necked heron State Botaurus poiciloptilus Australasian bittern National Egretta garzetta Little egret National Ixobrychus minutus Little bittern National

Ardeidae

Nycticorax caledonicus Nankeen night heron State Charadriidae Erythrogonys cinctus Red-kneed dotterel State

Phalacrocorax carbo Great cormorant Regional Phalacrocorax melanoleucos Little Pied cormorant State

Phalacrocoracidae

Phalacrocorax sulcirostris Little Black cormorant State Podicipedidae Podiceps cristatus Great crested grebe State

Fulica atra Eurasian coot State Gallinula ventralis Black-tailed native-hen Regional Gallirallus philippensis Buff-banded rail State Porphyrio porphyrio Purple swamphen Regional

Rallidae

Porzana pusilla Baillon's crake State Recurvirostridae Himantopus himantopus Black-winged stilt State

Platalea flavipes Yellow-billed spoonbill State Threskiornithidae Platalea regia Royal spoonbill National

Data source: Maher (1990)


Data source: Maher (1990)

Figure 14: Important waterbird feeding and breeding sites in Yanga National Park identified during the 1989–90 survey


4.2.8 Supports 11 migratory species covered in migratory bird agreements

The Lachlan–Murrumbidgee confluence was identified as an important migratory waterbird habitat (Pressey et al. 1984) in NSW and was covered in the Wildlife Conservation Plan for Migratory Shorebirds (DEH 2006) based on the population size of black-winged stilts (Himantopus Himantopus) and red-necked avocets (Recurvirostranovaehollandiae).

There are 11 migratory species covered by the international agreements for migratory birds (JAMBA, CAMBA, and ROKAMBA) recorded in Yanga National Park and adjacent areas. Most of the species recorded are listed in Table 11 and were considered uncommon or rare in the 1989–90 bird survey, except glossy ibis (Plegadis falcinellus), over 1000 nests of which were located in Suicide Swamp (Maher 1990).

Thirty-six species of migratory shorebirds regularly visit Australia, five of which have been recorded in Yanga National Park (Table 11), such as the sharp-tailed sandpiper (Calidris acuminate) and fork-tailed swift (Apus pacificus) (DEH 2006).

4.2.9 Supports large stands of primary producers

The Yanga floodplain is very productive, and was used extensively for agriculture and farming prior to 2005.

Currently, the majority of the national park is vegetated. In particular, there are over 21,000 ha of river red gum forests and about 12,000 ha of black box woodlands (McCosker 2008) which fuel river productivity though litter fall (Robertson et al. 1999; Gawne et al. 2007). The annual litter production of river red gum forest is amongst the highest in Australia (Briggs and Maher 1983). Although primary productivity has not been investigated for any of the vegetation community in Yanga National Park, using the range measured by Briggs and Maher (1983) in the same region the river red gum forests alone produce 78,378–123,195 tonnes of litter (leaf, fruit, flower, twigs and bark) annually.

Table 11: Migratory birds protected under international treaties

Family Common name Scientific name Legal status Apodidae Fork-tailed swift * Apus pacificus C, J, K Ardeidae Great egret Ardea alba C, J

Cattle egret Ardea ibis C, JAccipitridae White-bellied sea eagle Haliaeetus leucogaster CThreskiornithidae Glossy ibis Plegadis falcinellus CRostratulidae Painted snipe Rostratula benghalensis CScolopacidae Black-tailed godwit Limosa limosa C, J, K Sharp-tailed sandpiper * Calidris acuminate C, J, K

Latham's snipe * Gallinago hardwickii J Greenshank * Tringa nebularia C, J, K

Marsh sandpiper * Tringa stagnatilis C, J, K

C = CAMBA, J = JAMBA, K = ROKAMBA * Listed in DEH (2006)


4.2.10 Provides important feeding, spawning and nursing grounds for native fish

An extensive part of Yanga National Park can be inundated and is hydrologically linked with the Murrumbidgee River during overbank flow and flooding. Under flooding conditions, the national park provides extremely diverse habitats for fish. When inundated, many animals emerge from eggs, cysts and burrows in the soil, and become extremely productive (Baldwin and Mitchell 2000). A variety of aquatic fauna, including fish and reptiles, move from the main channel to floodplain habitats during overbank flows to take advantage of the rich food resources (Figure 15).

Fish use floodplain habitats for a variety of reasons, including shelter, feeding, spawning and recruitment (Junk et al. 1989). These habitats provide shelter during floods, away from the fast flows of the main channel. The low water velocity and high productivity of floodplain habitats makes them important feeding and nursery areas. Spawning in floodplain habitats can provide larvae and juveniles with safer conditions (e.g. protection from predation) and more food than the main waterway channel. Many south-eastern fish (see Table 18), such as silver perch (Bidyanus bidyanus), golden perch (Macquaria ambigua) and bony herring (Nematalosa ereb), spawn and shelter in floodplain habitats. The Murray hardyhead (Craterocephalus fluviatilis), an endangered species in the Murray–Darling Basin, lives along the edges of slow-flowing lowland rivers and in lakes, billabongs and backwaters. Although these species use floodplain habitats, there has been little research done on the importance of these habitats for them. Fish movement during flooding is generally unknown, and the dependence on the floodplain has not been thoroughly researched.

As the floodplain becomes more isolated from the Murrumbidgee River due to catchment-scale regulation and reach-scale development, Yanga National Park and the Lowbidgee floodplain are losing this service. For example, according to the latest fish survey, the introduced European carp dominated the majority of sampled habitats (Spencer and Allman 2008).

Based on Mussared (1997)

Figure 15: Floodplain wetlands as fish feeding, spawning and nursery habitat


4.3 Cultural services

4.3.1 Aboriginal heritage

Yanga National Park lies within the traditional tribal areas of both the Muthi Muthi and Wathi Wathi peoples, and has a rich Aboriginal heritage including associations with creation stories (Roberts 2005). Sites on the property already listed on the Aboriginal sites register include mounds, scarred trees, historic sites, burials and middens. Such sites and artefacts are highly valued by the Aboriginal community, as well as by the broader community. It is important that these sites are conserved as fragile and irreplaceable Aboriginal heritage, and the need to protect this heritage is recognised in legislation. The NSW National Parks and Wildlife Service (NPWS) has a statutory role in the protection and preservation of Aboriginal sites. The concern is essentially the need to reinforce the importance of this heritage, and ensure that Aboriginal sites and artefacts are reported to NPWS.

4.3.2 European heritage

Yanga National Park is an area of significance for early European settlement of the NSW Western plains. Yanga Station covered approximately 210,000 acres and was the largest privately owned station in the southern hemisphere. Yanga homestead was built around 1870 by the new owner, Dr (Sir) Charles Nicholson, for the station manager. Located 10 km south-east of Balranald, the homestead is of Georgian bungalow style with typically 1830s and 1840s features (Figure 16). It is situated on a rise looking eastward over terraced gardens and Yanga Lake. Yanga Station is recorded as being the first private property in Australia to have a telephone. The property also contains evidence of early horse and coach transport, early 20th century rail transport and soldier settlement blocks.

4.3.3 Scientific research

Yanga National Park has, since its gazettal, become a focus of inland floodplain wetland research. A number of studies covering hydrology, geomorphology, ecology, botany and zoology are underway at Yanga National Park and the broader Lowbidgee floodplain.

Photo: NPWS

Figure 16: Yanga homestead


5 Description of specified components that support selected ecosystem services

Ecosystems consist of various non-living, abiotic and living biotic components. The Ramsar Convention (2005) defines ecosystem components as the physical, chemical and biological parts of a wetland.

The abiotic components of an ecosystem include various physical and chemical factors. The physical factors that have the greatest effect on the ecological character of Yanga National Park are: � climate (section 2) � wetland size and connectivity � woody debris � soil and sediment (structure, texture, and profile) � fire.

The chemical factors include: � soil and sediment chemical properties (organic content, salt, nutrient level, pH) � water chemistry (total and bioavailable nutrient levels, salinity, pH, dissolved

oxygen, toxic substance concentration).

Organisms that make up the biotic component of an ecosystem are usually classified as autotrophs and heterotrophs, based on how they get the food or organic nutrients they need to survive, and include: � autotrophs (producers): terrestrial vegetation communities, aquatic plants and

phytoplankton, and periphytyes � heterotrophs (consumers): zooplankton, macroinvertebrates, vertebrates (fish,

amphibians, reptiles, waterbirds, and other mammals) � detritivores (decomposers and detritus feeders) and benthic microorganisms:

various bacteria and fungi.

Ecosystem components included in the description of wetland ecological character for Yanga National Park are summarised in Table 12.

5.1 Physical components of Yanga National Park

5.1.1 Important wetlands

The important wetlands (and wetland systems) and their basic features are listed in Table 13. Their locations are mapped in Figure 17.

Yanga Lake is about 8 km west of Balranald and at 1247 ha is the largest ‘permanent’ lake in the Balranald region. When full, it has about 24 km of shoreline. As early as the 1920s its environmental services and conservation values were noticed. For example, in 1909 the lake was noted as a reserve ‘for the reservation of Game’. In 1922, it was noted as a ‘sanctuary for birds and animals’. In 1923, the Australasian newspaper stated Lake Yanga was ‘an immense sheet of fresh water which had never been known to fail.’

However, as water development in the Murrumbidgee catchment progressed, especially the completion of Burrinjuck Dam and expansion of the MIA in the late 1920s (see Table 23 for major developments), Yanga Lake has had less chance to be flooded. In addition, Yanga Lake was not included in the area gazetted as the


Lowbidgee Flood Control and Irrigation District (FCID) in the 1940s. As a result, artificial floods to assist the Lowbidgee are unlikely to reach Yanga Lake. Consequently, the ‘permanent’ lake dried up in 2001 and has stayed dry since then. The long-term dry period eradicated the aquatic biota, and saltbush has developed (Figure 18).

Tala Lake used to be a vast expanse of deep open water with river red gums scattered around its periphery. It was used as an irrigation water storage. Before it dried up in 2001, the water level was maintained at an artificial high level resulting in the death of some old river red gums (Figure 19).

Piggery Lake is a large shallow lake with mean depth of about 1.5 m and can hold water for up to 18 months (Pressey et al. 1984). It is surrounded by river red gums and has extensive beds of common water milfoil (Myriophyllum propinquum) and water primrose (Ludwigia peploides) when inundated (Figure 20). A series of banks has been constructed to hold water in the lake.

Shallow marshes include Two Bridges Swamp (Figure 21) and Mercedes Swamp (Figure 22). Tall spike rush (Eleocharis sphacelata) is the dominant aquatic plant in these swamps. It can grow as understorey in sparse river red gum forest or form dense single species stands.

Table 12: Ecosystem components of Yanga National Park

Category Components Condition and trend Important wetland Stressed and declining Wood debris Increasing

Physical

Fire Increased fire risk Organic content Generally low, high at river red gum

forest/woodland Nutrient level General low, more information needed

Soil

Exchange capacity High Salinity Variable, can be very high in lakes due to

evaporationNutrient level High to very high in terms of phosphorus,

especially in fresh inundated lakes and swamps pH Variable, can be low because of tannic acid

Water chemical

Dissolved oxygen Variable, can be very low due to accumulated organic matter

Vegetationcommunities

Majority in poor to very poor condition and declining

Waterbirds Evidence of collapsed waterbird population and declining

Fish Some species may locally extinct. Population of native fish is declining but more data and information are needed.

Frogs Population size declining particularly for the endangered southern bell frog mainly due to habitat loses and fragmentation

Other animals Maintained but some populations are decreasing

Biota

Plant species Maintained either in living stands or seedbank, but more data and information are needed.


Data source: Childs (2009)

Figure 17: Locations of the 23 wetlands listed in Table 13

40

Description of wetland ecological character

Tabl

e 13

: Im

porta

nt w

etla

nds

with

in Y

anga

Nat

iona

l Par

k

Nam

e#A

rea

(ha)

Vo

lum

e(M

L)Fe

edin

g ch

anne

lLa

st fl

ood^

Ec

olog

ical

sig

nific

ance

Sha

w’s

Sw

amp

200

3200

M

urru

mbi

dgee

20

05–0

6

Sha

w’s

Sw

amp

cons

ists

of a

rive

r red

gum

and

tall

spik

e ru

sh

vege

tatio

n co

mm

unity

and

is a

n im

porta

nt n

estin

g si

te fo

r col

onia

l w

ater

bird

spe

cies

.W

augo

rah

Lake

60

96

0 W

augo

rah

Cre

ek

2000

–01

Riv

er P

addo

ck

Sw

amp

40

640

Mur

rum

bidg

ee

2000

–01

Wau

gora

h La

ke a

nd R

iver

Pad

dock

Sw

amp

are

natu

ral

depr

essi

ons

that

rece

ive

wat

er a

fter S

haw

’s S

wam

p is

com

plet

ely

fille

d an

d w

ere

once

dev

elop

ed fo

r cro

ppin

g by

Yan

ga S

tatio

n.

Wau

gora

h La

ke is

fille

d w

ith d

omes

tic a

nd s

tock

wat

er a

nd n

ever

dr

ies.

B

oth

wet

land

s ar

e co

nsid

ered

to b

e in

tegr

al fo

ragi

ng s

ites

for

wat

erbi

rds

nest

ing

in S

haw

’s S

wam

p an

d N

orth

Sta

llion

Sw

amp.

H

oble

rs L

agoo

n 10

16

0 M

urru

mbi

dgee

P

erm

anen

tly

linke

d w

ith th

e M

urru

mbi

dgee

This

is o

ne o

f few

wet

land

s w

ithin

Low

bidg

ee th

at h

as m

aint

aine

d co

nnec

tivity

to th

e riv

er, a

nd th

us p

rovi

des

unim

pede

d pa

ssag

e fo

r nat

ive

fish

to e

nter

and

spa

wn.

N

orth

Sta

llion

Sw

amp

100

1600

W

augo

rah

Cre

ek

2000

–01

This

sw

amp

com

pris

es a

div

ersi

ty o

f veg

etat

ion

type

s in

clud

ing

river

red

gum

, bla

ck b

ox, l

ignu

m a

nd ri

ver c

ooba

(Aca

cia

sten

ophy

lla).

Top

Cre

ek

Sw

amp

150

2400

To

p C

reek

20

05–0

6 Th

is is

an

impo

rtant

nes

ting

site

for c

olon

ial w

ater

bird

spe

cies

.

Mer

cede

s S

wam

p 75

56

3 M

urru

mbi

dgee

20

08–0

9 M

erce

des

Sw

amp

is d

omin

ated

by

tall

spik

e ru

sh a

nd fr

inge

d by

la

rge

river

red

gum

s. It

is a

n im

porta

nt s

outh

ern

bell

frog

recr

uitm

ent s

ite (W

asse

ns e

t al.

2008

a), a

nd is

fille

d by

the

Mur

rum

bidg

ee R

iver

via

the

Mer

cede

s re

gula

tor.

Poc

ocks

Sw

amp

18

207

Ove

rflow

from

M

erce

des

Sw

amp

2008

–09

The

vege

tativ

e st

ruct

ure

of th

e w

etla

nd c

ompr

ises

rive

r red

gum

fo

rest

with

a m

acro

phyt

ic u

nder

stor

ey th

at c

onta

ins

spar

se b

eds

of ta

ll sp

ike

rush

, com

mon

reed

and

cum

bung

i(Ty

pha

orie

ntal

is).

The

wet

land

per

imet

er c

ompr

ises

a ri

ver r

ed g

um fo

rest

and

a

dens

e gr

ound

laye

r of w

arre

go s

umm

er g

rass

(Pas

palid

ium

ju

biflo

rum

).La

rge

num

bers

of c

orm

oran

ts u

tilis

e th

e riv

er re

d gu

ms

to ro

ost,

and

duck

s, h

eron

s an

d eg

rets

are

com

mon

ly o

bser

ved

fora

ging

on

the

swam

p. T

he s

truct

ural

div

ersi

ty o

f the

sw

amp

and

its

mar

gins

als

o su

ppor

t a d

iver

se c

omm

unity

of l

and

bird

s.


Nam

e#A

rea

(ha)

Vo

lum

e(M

L)Fe

edin

g ch

anne

lLa

st fl

ood^

Ec

olog

ical

sig

nific

ance

Top

Nar

ockw

ell

Sw

amp

500

6000

O

verla

nd fl

ow

2004

–05

This

is a

n im

porta

nt n

estin

g si

te fo

r col

onia

l wat

erbi

rd s

peci

es.

The

Ave

nue

(Tw

o B

ridge

s)

300

2550

Y

anga

regu

lato

r ch

anne

l 20

08–0

9 Th

e m

ain

flood

way

whe

re E

WA

ent

ers

Yan

ga N

atio

nal P

ark.

D

iver

se v

eget

atio

n co

mm

unity

. K

ey s

outh

ern

bell

frog

recr

uitm

ent s

ite (W

asse

ns e

t al.

2008

a).

Fora

ging

are

a fo

r col

onia

l nes

ting

wat

erbi

rds

(Mah

er 1

990)

. P

igge

ry L

ake

and

Li

ttle

Pig

gery

15

0 22

88

Ove

rland

flow

20

04–0

5 K

ey s

outh

ern

bell

frog

recr

uitm

ent s

ite (W

asse

ns e

t al.

2008

a).

Impo

rtant

bre

edin

g an

d fo

ragi

ng a

rea

for w

ater

bird

s (M

aher

199

0,

2006

). La

rge

open

wat

er a

rea

whe

n fil

led.

N

arku

nger

ie

Sw

amp

200

2300

O

verla

nd fl

ow

2004

–05

Impo

rtant

fora

ging

site

wat

erbi

rds.

Riv

er S

myt

hs

150

1725

O

verla

nd fl

ow

2004

–05

Im

porta

nt n

estin

g, b

reed

ing

and

fora

ging

site

.

Bre

er S

wam

p 50

0 60

00

Ove

rland

flow

20

04–0

5 Im

porta

nt n

estin

g, b

reed

ing

and

fora

ging

site

.

Bre

er C

reek

S

wam

p10

00

12,0

00

Ove

rland

flow

20

04–0

5 Th

e on

ly s

ite w

ith s

igni

fican

t siz

e w

ithou

t con

stru

cted

ban

ks

(Mah

er 1

990)

. Im

porta

nt fe

edin

g si

te fo

r wat

erbi

rds.

E

gret

Sw

amp

150

1800

O

verla

nd fl

ow

2004

–05

Im

porta

nt n

estin

g, b

reed

ing

and

fora

ging

site

. Ta

rwilli

e S

wam

p 20

0 24

00

Ove

rland

flow

20

04–0

5 A

maj

or c

olon

ial w

ater

bird

rook

ery.

Ta

la S

wam

p 80

0 15

,200

O

verla

nd fl

ow

and/

or N

imm

ie–

Cai

ra s

yste

m (v

ia

Tala

Lak

e)

1999

–200

0 W

ater

bird

fora

ge s

ites.

Dev

ils C

reek

S

wam

p20

0 24

00

Ove

rland

flow

an

d/or

Nim

mie

–C

aira

sys

tem

(via

Ta

la L

ake

and/

or

Uar

a C

reek

)

1999

–200

0 A

n im

porta

nt b

reed

ing

habi

tat f

or g

reat

cre

sted

gre

bes

(Pod

icep

s cr

ista

tus)

and

an

impo

rtant

nes

ting

and

feed

ing

area

for o

ther

w

ater

bird

s, p

artic

ular

ly c

orm

oran

ts.


Nam

e#A

rea

(ha)

Vo

lum

e(M

L)Fe

edin

g ch

anne

lLa

st fl

ood^

Ec

olog

ical

sig

nific

ance

Yan

ga L

ake

1324

35

,086

Y

anga

Cre

ek

1999

–200

0 O

ne o

f the

larg

est l

akes

in w

este

rn N

SW

. Im

porta

nt w

ater

bird

hab

itat b

efor

e it

drie

d ou

t in

2001

. Im

porta

nt fi

sh h

abita

t, a

NS

W fi

sher

ies

stoc

king

site

in

Mur

rum

bidg

ee c

atch

men

t to

boos

t nat

ive

fish

popu

latio

n be

fore

it

drie

d ou

t in

2001

. Fi

nger

boar

d*

1402

14

,015

U

ara

Cre

ek

1989

–90

An

impo

rtant

ana

bran

ch o

f the

Mur

rum

bidg

ee R

iver

bef

ore

Eur

opea

n se

ttlem

ent.

How

ever

, flo

ws

are

curre

ntly

reta

ined

with

in

the

Low

bidg

ee F

CID

by

a se

ries

of e

arth

en b

lock

ban

ks, a

nd

ther

e ha

s be

en n

o flo

w in

to Y

anga

Nat

iona

l Par

k si

nce

the

early

19

90s.

P

rovi

des

habi

tat f

or a

div

erse

rang

e of

faun

a, in

clud

ing

smal

l m

amm

als

such

as

the

com

mon

dun

nart

(Sm

inth

opsi

s m

urin

a) a

nd

fat-t

aile

d du

nnar

t (S

min

thop

sis

cras

sica

udat

a), a

nd w

oodl

and

bird

sp

ecie

s in

clud

ing

the

thre

aten

ed re

dthr

oat (

Ser

icor

nis

brun

neus

)an

d ho

oded

robi

n (M

elon

adry

as c

ucul

lata

).Y

anga

Nat

ure

Res

erve

* 28

92

28,9

19

Fidd

lers

Cre

ek

<10%

of t

he

area

rece

ived

w

ater

in 1

989–

90

His

toric

ally

rece

ivin

g w

ater

in la

rge

flood

s (1

in 5

–7 y

ears

). N

o flo

w s

ince

the

early

199

0s.

Flor

al d

iver

sity

.

Con

doup

le

Cre

ek*

403

4026

Y

anga

Lak

e 19

89–9

0 Fl

oral

div

ersi

ty.

Dat

a so

urce

: Chi

lds

(200

9)

# W

etla

nds

liste

d fro

m n

orth

-eas

t to

sout

h-w

est.

* It

is m

ore

appr

opria

te to

be

man

aged

as

terre

stria

l eco

syst

em c

onsi

derin

g th

e lo

ng d

ry p

erio

d an

d th

e lo

w p

roba

bilit

y of

rece

ivin

g w

ater

in th

e fu

ture

.

^ Th

e m

ajor

ity o

f wet

land

s w

ere

artif

icia

lly in

unda

ted

as th

e Lo

wbi

dgee

has

not

rece

ived

nat

ural

ove

rban

k flo

ws

sinc

e th

e 19

90s.


Photo: J Kelleway

Figure 18: The early development of saltbush at Yanga Lake in 2007

Photo: J Kelleway

Figure 19: Tala Lake in 2007, showing dead river red gums caused by permanent inundation before it dried out in 2001


Photo: J Maguire, 2001 Photo: J Kelleway, 2007

Figure 20: Piggery Lake when inundated (left) and dry (right)

Photo: Li Wen/OEH, Devember 2007 Photo: Li Wen/OEH, April 2008

Figure 21: Two Bridges swamp before (left) and after (right) receiving environmental water allocation

Photo: Li Wen/OEH, December 2007 Photo: Li Wen/OEH, April 2008

Figure 22: Mercedes Swamp before (left) and after (right) receiving environmental water allocation


5.1.2 Large woody debris

Woody debris refers to whole trees or piles of twigs and branches that are deposited on a floodplain (Figure 23) or in a river channel (Figure 24) during a flood. It has a number of important functions in the river–floodplain system, one of which is the provision of regeneration sites for floodplain forest species. Where woody debris is deposited, it creates an obstacle to river flow. Depressions are scoured upstream of the debris and then become filled with fine sediments creating a moist microsite suitable for the regeneration of riparian species such as river red gums. In addition, large amounts of fine sediment are deposited at the downstream end of the woody debris forming another type of microsite rich in trapped nutrients, organic matter and seeds. These slightly raised, semi-protected sites tend to support dense patches of riparian species seedlings as well as aquatic plants, such as common reed (Phragmites australis).

Woody debris in streams can also function directly as ‘nurse logs’ for the colonisation of certain aquatic species providing surfaces for organisms to attach to, shelter for breeding and protection against predators. In the lower Murrumbidgee River, which has muddy beds and banks, woody debris is particularly important as it is the only stable surface to which microscopic plants and animals can attach.

In the floodplain, falling trees and branches also provide microhabitats for terrestrial biota including amphibians, reptiles and woodland birds during the dry phase (Mac Nally et al. 2001; Tockner et al. 2006).

Photo: Li Wen/OEH

Figure 23: Piles of river red gum branches which provide habitat for amphibians, reptiles, birds and small mammals


Photo: H Smith/OEH

Figure 24: A fallen tree in the Murrumbidgee River channel downstream from Redbank Weir providing a surface for algae, microscopic plants and animals

5.1.3 Fire

As a natural element, fire has not only helped shape the environment, it has also been one of the driving forces in the evolution of native fauna and flora in Australia generally (Abbott and Burrows 2003). Prior to 2005, controlled fires were set deliberately to increase the prevalence of grasses (for grazing) and clearing floodways (for irrigation) in Yanga (R Hampton 2008, pers. comm.). Although it is generally agreed that natural fire plays an important role in determining the diversity, distribution and abundance of flora and fauna in floodplain ecosystems, there is no information about the fire regime (type, frequency, season and intensity of a fire) in Yanga National Park.

5.2 Chemical components

5.2.1 Soil chemistry

In 2008 the Department of Environment and Climate Change (DECC) completed a detailed soil survey in Yanga National Park (EAS 2008). The following information is a summary of data collected by the Yanga Soil Survey project (Table 14), which sampled 13 sites in Yanga National Park (Figure 25).

� Soil exchange capacity is high (generally greater than 30 meq/100 g) throughout the park, corresponding to the high soil clay content. The soil has a high ability to hold nutrients, minerals and water.


� The top layer (0–30 cm) of soil has a generally low salinity level (EC1:5 <0.3 dS/m), except for one site on red soil with chenopod shrubland, which has an elevated EC level (EC1:5 >3.5 dS/m). However, soil salinity levels generally increase with depth.

� The top soil generally has a low sodicity value (exchangeable sodium percentage, ESP <5) except the chenopod shrubland site, which is strongly sodic. However, ESP generally increases with depth in two lakes (Yanga and Piggery) which have a relatively low value for the whole soil profile.

� Soil pH varies from slightly acid (6.2< pH1:5 <6.7) to strongly alkaline (>8.5).

� The organic carbon is low (<1%) throughout the park, with a relatively higher value at river red gum forest/woodland.

5.2.2 Water quality

The NSW Department of Land and Water Conservation (DLWC) commenced a comprehensive valley-wide water quality monitoring program in the Murrumbidgee River in 1990, continued regularly at four key sites in Yanga National Park (Kneebone 1995). In addition, in 1998–2000 the catchment monitoring services of DLWC carried out a water quality and flow assessment program for the Redbank Irrigation District, which included nine addition field sites in Yanga National Park (Cawley 2000). After 2000, the majority of wetlands within the Yanga floodplain have been dry, and there has been no systemic water quality monitoring. The following description of selected water chemical parameters is summarised from the water quality and flow assessment program (Kneebone 1995; Cawley 2000).

Table 14: Soil chemistry characteristics in Yanga National Park, average values for a 1-m soil profile

Site1 CEC2 ESP3 EC pH OC4 Soil type and vegetation Ya02 48.3 8.4 0.3 9.29 0.73 Black box woodland on grey soil Ya03 35.2 7.4 0.2 7.30 0.90 River red gum forest on grey soil Ya04 44.2 13.1 0.9 6.73 0.90 River red gum forest on grey soil Ya11 36.1 7.1 0.2 7.62 0.90 River red gum forest on grey soil Ya13 39.5 0.9 1.0 7.06 0.90 River red gum woodland on grey soil Ya20 38.4 7.7 0.2 7.61 0.90 River red gum woodland on grey soil Ya21 26.3 3.7 0.1 8.71 0.73 Black box woodland on brown soil Ya27 28.6 8.9 0.3 6.29 0.90 River red gum woodland on grey soil Ya43 29.7 6.2 0.2 6.87 0.90 Lignum swamp on grey soil Ya54 38.8 13.3 0.3 8.44 0.90 River red gum woodland on brown soil Ya108 62.5 40.9 3.9 8.58 0.73 Chenopod shrubland on red soil Ya119 29.1 5.2 0.2 7.21 0.68 Piggery Lake Ya111 36.3 2.9 0.2 7.60 0.68 Yanga Lake

Data source: EAS (2008) 1 Refer to Figure 25 for site location; 2 CEC = exchange capacity (meq/100 g) 3 ESP = exchangeable sodium percentage (%) 4 OC = Organic carbon content (5%)


725000 730000 735000 740000 745000 750000 755000 760000 765000 770000 775000

6135000

6140000

6145000

6150000

6155000

6160000

6165000

6170000

6175000

6180000

6185000

6190000

6195000

6200000

6205000

Ya02

Ya03Ya04

Ya108

Ya11

Ya111

Ya119

Ya13

Ya20Ya21

Ya27

Ya43

Ya54

Figure 25: Soil sampling sites at Yanga National Park


Generally, water quality in water bodies (swamps, creeks and canals, lakes and water storages) within the Yanga floodplain is affected by a range of factors. These factors include source water (the Murrumbidgee vs Nimmie–Caira FCID), distance from source water (travel time), physical features of the water body (open water vs vegetated) and flow path (channelled vs overland).

Salinity level is generally low and within the ANZECC guidelines for freshwater ecosystems (ANZECC & ARMCANZ 2000). However, in lakes (such as Yanga Lake and Tala Lake) and isolated pools, salinity could exceed the guidelines due to condensation due to evaporation.

Total phosphorus concentration (TP) in the Murrumbidgee River from Hay to Balranald is poor and exceeds the ANZECC lowland river trigger value of 50 μg/L (DLWC 1995). Once water enters the floodplain, TP concentration increases as it flows across the land, suggesting that phosphorus is being released from the topsoil. Because there is little relationship between TP and turbidity in the floodplain, the decay of litter and vegetation is thought to be the main contributor.

Total nitrogen concentration was not measured in the DLWC programs. In a study to investigate the pollution sources in the lower Murrumbidgee River, the State Pollution Control Commission had a sampling site at the centre of the Murrumbidgee River at Balranald Pumping Station No 2 (SPCC 1976). The results indicated that the nitrogen concentration was very low (50–110 μg/L) compared to the ANZECC guideline of 500 μg/L.

pH is generally neutral to slightly alkaline in the river channel and most of the time is within ANZECC guidelines. In the floodplain, pH is lower (less alkaline) reflecting the influence of tannic acid and the breakdown of plant materials.

Dissolved oxygen (DO) concentrations should be 80–120% for lowland rivers and 90–120% for freshwater wetlands according to the ANZECC guidelines (ANZECC & ARMCANZ 2000). Water in the Murrumbidgee River at Redbank and Balranald Weir was assessed as poor (DO concentration 20–80%) (DLWC 1995) and variable (Cawley 2000). However, DO levels in the Murrumbidgee channel were more consistent and within the ANZECC guidelines at most times. In the floodplain waters, DO levels were generally lower than the 90% saturation threshold, except in larger open waters (such as Yanga Lake and Tala Lake). The lower DO level was possibly due to bacterial oxygen demand to break down accumulated organic matter.

Turbidity at Redbank and Balranald weirs was normally within the ANZECC guidelines (6–50 NTU). In Lake Yanga and Tala Lake, turbidity was much higher than in other waters due to wind mixing and lake-bed load. In other shallow swamps, turbidity was low and normally under 100 NTU. In irrigation canals, flowing water could be very turbid.

Tannic acid, which gives water a dark brown colour, is a polyphenol and is present in trees like river red gum and black box. The concentration of tannic acid is low in the Murrumbidgee (0.2 mg/L: Cawley 2000). When water enters the floodplain and comes into contact with litter, tannin is released and the tannic acid concentration increases. Because of its relatively stable chemical structure, the concentrations appear to be cumulative in the short term (they tend to continuously increase with increased exposure to litter); thus, the receiving waters in the drainage basins normally have greater concentrations. In Yanga Lake and Tala Lake, however, tannic acid concentrations were lower than in the source waters suggesting the breakdown of tannin under conditions associated with the lakes (very long residence time, high turbidity, alkaline).


5.3 Biological component of Yanga National Park

5.3.1 Important plant communities

The assemblages of plant species that often grow at the same location are known as plant communities. The distribution of different plant communities across landscapes is influenced by various factors, such as climate, position in the landscape, biological interactions and site history (for example bushfires, floods, human activities such as land clearing and logging).

Scott (1992) mapped nine communities in Yanga National Park. A rapid field inspection in 2005 by NPWS revealed a further three localised vegetation types (Benson et al. 2006). In 2008, DECC committed a project to map the historic vegetation extent and condition in Yanga National Park which identified 17 vegetation classes from five formation groups (McCosker 2008) (Table 15). The distribution of vegetation communities in Yanga National Park at 2005 is shown in Figure 26.

The boundaries of major plant communities remain relatively unchanged from the 1960s (McCosker 2008). However, the canopy cover and condition for each community are generally poor to very poor, with the exception of small areas receiving regular controlled flooding (irrigation), which are in good condition (Table 15). These areas include Two Bridge Swamp and surrounds, Shaw’s Swamp and surrounds, and Waugorah Creek and Pee Vee Creek (McCosker 2008).

Of the 17 vegetation types in McCosker (2008), river red gum forest/woodland, black box woodland, lignum/nitre goosefoot (Chenopodium nitrariaceum) shrubland, and spike rush (Eleocharis spp.) dominated sedgeland are identified as important and described in detail here.

River red gum community

River red gum forest/woodland occurs along rivers, creeks, levees and adjacent flats, channelled plains and other areas subject to frequent or periodic flooding. It is usually on heavy grey, brown and red clays (Porteners 1993).

In Yanga National Park there are over 22,000 ha of river red gum forests/woodlands which cover the majority of the section north of Yanga Lake (Figures 24 and 25). The community was further classified into four sub-classes by Benson et al. (2006) and McCosker (2008):

� river red gum tall gallery forest (1083 ha) which lines the main channel of the Murrumbidgee, including levees

� river red gum forest with a dense sedge understorey dominated by common spike rush (Eleocharis acuta) (4622 ha) which occurs on flats of black, self-mulching clay and the bed of intermittent lakes

� river red gum woodland with grassy understorey (3689 ha)

� river red gum forest with a shrubby lignum understorey (11,926 ha).


Data source: McCosker (2008), based on 2005 aerial photography

Figure 26: Vegetation distribution in Yanga National Park


Table 15: Plant communities found within Yanga National Park

Formation Class Characteristic species Structure Condition+ Threat * Area (ha)^

Yarran shrubland

Acacia melvillei; Eremophila sturtii; Enchylaena tomentosa; Dissocarpus paradoxus; Sclerolaena obliquicuspis

Openshrubland

Fair – poor 1 and 5

720

Acacia Woodlands andShrublands of the Inland Slopes and Plains

Prickly wattle shrubland

Acacia victoriae subsp. arida; Dodonaea viscosa subsp.angustissima; Enchylaena tomentosa; Dissocarpus paradoxus

Openshrubland

Poor 5, 3, 7

14

Black bluebush low openshrubland

Maireana pyramidata; Rhagodia spinescens; Maireana georgei; Atriplex vesicaria sens lat.; Scleroleana obliquicuspis; Enchylaena tomentosa; Austrostipa nitida; Calotis hispidula

Open/sparse chenopod shrubland

1 and 5

Pearlbluebush low openshrubland

Maireana sedifolia; Maireana pyramidata; Atriplex vesicaria sens lat.; Maireana sclerolaenoides; Enchylaena tomentosa; Sclerolaena obliquicuspis; Sclerolaena patenticuspis; Austrostipa nitida


Poor – very poor

5 5086

Bladder saltbush shrubland

Atriplex vesicaria sens lat.; Pachycornia triandra; Sclerostegia tricuspis; Disphyma crassifolium subsp. clavellatum; Sclerolaena brachyptera; Dissocarpus biflorus var. biflorus; Chloris truncata

Openchenopod shrubland

1, 5, 9, 10

Old man saltbush shrubland

Atriplex nummularia; Rhagodia spinescens; Maireana microcarpa; M. pyramidata; A. vesicaria sens lat.; Dissocarpus biflorus; Osteocarpum acropterum var.acropterum; A. lindleyi; Chloris truncata


Poor

5, 1, 6, 8,4

32

Nitregoosefoot shrubland

Chenopodium nitrariaceum; Sclerolaena muricata sens lat.; S.stelligera; Malacocera tricornis

Openchenopod shrubland

1, 9, 2, 4, 5

Cotton bush openshrubland

Maireana aphylla; Sclerolaena tricuspis; Calocephalus sonderi; Rhodanthe corymbiflora; Austrodanthonia caespitosa


Poor – very poor

2, 5, 8, 9 6064

Chenopod (Halophytic) Shrublands of the Inland

Dillon bush shrubland

Nitraria billardierei; Rhagodia spinescens; Sclerolaena tricuspis; Austrostipa scabra subsp. scabra

Sparsechenopod shrubland

Poor – very poor

8, 5, 6 13,521

Cypress Pine (Callitris) Woodlands Mainly of the Inland

Slender cypress pine – sugarwood – western rosewoodopenwoodland

Callitris gracilis subsp. murrayensis;Myoporum platycarpum subsp.platycarpum; Alectryon oleifolius subsp. canescens; Dodonaea viscosa subsp. angustissima; Maireana pentagona; Sclerolaena obliquicuspis; Zygophyllum apiculatum; Austrostipa nodosa

Openwoodland, isolated trees

Poor 1, 3, 8, 6

4827


Formation Class Characteristic species Structure Condition+ Threat * Area (ha)^

River red gum riparian open forest

Eucalyptus camaldulensis subsp.camaldulensis; Eleocharis acuta-Centipeda cunninghamii-Ranunculus inundatus-Pseudoraphis spinescens

Open forest Good – fair 4, 3, 2, 5, 6

1083

River red gum woodland with sedge groundcover

Eucalyptus camaldulensis subsp.camaldulensis; Eleocharis acuta, Paspalidium jubiflorum; Wahlenbergia fluminalis; Senecio quadridentatus; Carex tereticaulis

Open forest Poor – very poor, smallstands in goodcondition

4, 3, 2, 5, 6

4622

River red gum woodland with grass groundcover

Eucalyptus camaldulensis subsp.camaldulensis; Austrodanthonia caespitosa; Juncus flavidus; Carex inversa

Woodland Poor – very poor, dead tree stands

4, 1, 2, 3, 5, 6 3689

River red gum forest with shrubbyunderstorey

Eucalyptus camaldulensis subsp.camaldulensis; Acacia stenophylla; Muehlenbeckia florulenta; Paspalidium jubiflorum; Cyperus gymnocaulos; Einadia nutans subsp. nutans

Open forest woodland

Poor – very poor, dead tree stands

4, 1, 2, 3, 5, 6

11,926

Black box - lignumwoodland

Eucalyptus largiflorens; Muehlenbeckia florulenta; Chenopodium nitrariaceum; Einadia nutans subsp. nutans; Paspalidium jubiflorum; Sclerolaena muricata var. muricata; Austrodanthonia caespitosa

Woodland, openwoodland

Poor – very poor

1, 2, 4, 5, 6

3020

Eucalyptus Communities of Inland Watercourses and Inner Floodplains

Black box open wood-land with chenopod understorey

Eucalyptus largiflorens; Chenopodium nitrariaceum; Maireana pyramidata; Einadia nutans subsp. nutans; Sclerolaena divaricata; Atriplex semibaccata

Openwoodland, woodland

Poor – very poor, dead tree stands

1, 2, 4, 5, 6

9044

Shallowmarsh of regularly floodeddepressions

Eleocharis acuta; Pseudoraphis spinescens; Persicaria hydropiper; Lachnagrostis filiformis; Ludwigia peploides subsp. montevidensis; Myriophyllum crispatum

Forbland Poor – very poor, someareas excellent

4, 5, 6 650

Lignumshrubland of the semi-arid (warm) plains

Muehlenbeckia florulenta; Chenopodium nitrariaceum; Sclerolaena tricuspis; Senecio cunninghamii var. cunninghamii; Einadia nutans subsp. nutans

Openshrubland, chenopod shrubland

Very poor 1, 2, 4, 5 1336

Freshwater Wetlands: InlandAquatic,Swamp and Shrubland Communities

Permanent and semi-permanent freshwater lakes

Eleocharis sphacelata; Bolboschoenus medianus; Carex fascicularis; Lemna disperma; Azolla filiculoides; Myriophyllum crispatum; Potamogeton tricarinatus

Forbland, openforbland,opensedgeland

Poor – very poor, someareas excellent

1, 2, 4, 7, 8, 6

1900

Data sources: Benson et al. (2006); McCosker (2008) + Based on field assessment made in 2007 and 2008 * 1 = Land clearing, 2 = Cropping; 3 = Logging; 4 = Hydrology disruption; 5 = Grazing;

6 = Introduced species; 7 = Eutrophication; 8 = Erosion; 9= disease; 10 = Fire. ^ McCosker’s (2008) vegetation mapping based on 2005 aerial photography. In the vegetation

map, one class – scald areas with scattered blue bush, dillon bush grassland (5086 ha) – was not included.


The majority of river red gum communities are severely stressed except the small areas of riparian forest lining the Murrumbidgee River and Pee Vee Creek, which deliver irrigation water to Tala Lake, and other patches which have been regularly irrigated. The stands of river red gum in good condition are general located along the floodway from Yanga regulator to upstream of Piggery Lake. Downstream of Piggery Lake to upstream of Yanga Lake the communities are either severely stressed or dead (Figure 27).

Black box woodland

Black box woodland typically occurs on the less frequently flooded areas of the floodplain above the level of the adjacent river red gum forest. The understorey of the black box woodlands is variable and may include nitre goosefoot, thorny saltbush (Rhagodia spinescens), old man saltbush and lignum.

The extent of black box woodland has remained constant at about 12,000 ha since 1965 (McCosker 2008). However, black box in most areas displayed symptoms of stress, with bare branches (dieback) and epicormic shoots evident. The patches of dead mature cooba in black box woodland is not uncommon throughout Yanga National Park.

Lignum/nitre goosefoot shrubland

Lignum forms a kind of shrubland adjacent to major creeks and rivers and in low-lying swampy areas on heavy grey cracking clays (Porteners 1993). It can withstand infrequent but prolonged flooding and can form dense, almost impenetrable, stands (Porteners 1993; Cunningham et al. 1981). It commonly occurs on channelled plains and depressions with impeded drainage and is often associated with river red gum and black box as an understorey (Figure 28).

Lignum swamps that have been subject to regular inundation become dense and tall and are favoured breeding sites for many waterbird species (Figure 29). These types of lignum swamp are quite rare and the lignum swamps around the Lowbidgee floodplains were identified in 1990 as supporting the best stands in NSW and possibly eastern Australia (Maher 1990). Nitre goosefoot is co-dominant with lignum in some locations with an inconsistent ground cover, depending on flooding history.

There are currently around 7000 ha lignum/nitre goosefoot shrublands in Yanga National Park. Their condition has deteriorated over the 40 years of sampling (1965–2005) (McCosker 2008).

Spike rush dominated sedgeland

This general term covers many shallow low-lying areas scattered throughout the better-watered parts of the floodplain. Under a natural flow regime, these areas are subjected to irregular but frequent (once every 2–3 years) inundation (Maher 1990), but regularly refilled by divisions via Yanga regulator and Waugorah regulator after gazettal as the Lowbidgee FCID in 1944. They are generally small, ranging in size from less than one to several hundreds of hectares, and have different geomorphic histories.

In Yanga National Park, these areas are generally dominated by common spike-rush and occasionally cohabit with tall spike-rush (E. sphacelata) in standing water or recently wet areas. Associated water plants include common nardoo (Marsileadrummondii), smooth nardoo (Marsilea mutica), water milfoils (Myriophyllum spp.),wavy marshwort (Nymphoides crenata), water couch (Paspalum distichium), common joyweed (Alternanthera nodiflora) and buttercups (Ranunculus spp.); lagoon saltbush


(Atriplex suberecta) and black rolypoly (Sclerolaena muricata subsp. muricata) grow in wetland margins. Common reed is regenerating in places, particularly where it is protected from grazing by fallen logs and windrows left by logging operations.

Data source: McCosker (2008)

Figure 27: Condition of river red gums in 2005 based on aerial photography


Photo: J Maguire/OEH, 2005

Figure 28: Lignum swamp at the Fingerboards in Lowbidgee with black box in the background

Photo: J Maguire/OEH, 2005

Figure 29: Lignum swamps, which provide important waterbird breeding habitat in the Lowbidgee floodplain


5.3.2 Waterbirds

A number of bird surveys have been undertaken in the region which includes part of Yanga National Park (Pressey et al. 1984; Maher 1990, 2006; Magrath 1992; Bales 1999; Kingsford and Porter 2006; Spencer and Allman 2008). A summary of these surveys is presented in Table 16.

Pressey et al. (1984) identified 114 bird species. They noted that the range of birds observed was generally similar to what had been recorded by a number of observers in 1923, 1940 and 1961. However, they also noted that a number of ground-living birds, notably the plains wanderer (Pedionomus torquatus), southern stone-curlew (Burhinusgrallarius), Australian bustard (Ardeotis australis) and the brolga (Grus rubicunda), had either declined or become locally extinct. They attributed this to the effect of feral animals or grazing practices. They also suggested that, at the time of the survey, the number of wetland species observed may have been depressed by the dry conditions, and the number of honeyeater species by the lack of flowering trees.

Maher (1990) recorded a total of 164 species of birds during his survey. These consisted of 61 species which were classified as waterbirds and 103 which were land birds. Sixteen of the waterbirds were colonial nesting species. Results were presented for the habitat preference of the birds. River red gum forested wetlands, in conjunction with adjacent reed or rush dominated swamps, were identified as the most important habitat for waterbird breeding. Of 42 species found in the river red gum forest 30 were confirmed as breeding and this habitat was the main breeding habitat for 11 of the colonial nesting bird species. The presence of the reed/rush habitat within a reasonable proximity to the colonial nesting sites was considered important in providing feeding grounds.

The highest number of waterbirds were found in shallow marsh/reed/rush habitats (Maher 1990). A total of 53 waterbird species were observed, of which 17 were confirmed as breeding. The second most popular habitat for waterbirds was found to be lignum/nitre goosefoot dominated swamps where 50 species were observed, 21 of which were breeding. The lowest number of waterbirds, 36, of which 10 were breeding, were observed in black box swamps. Open water was an important breeding ground for a small number of species, in particular gull-billed terns (Gelochelidon nilotica) and silver gulls (Chroicocephalus novaehollandiae), but was more important as a major feeding area particularly as floodwaters receded. Flooded cropland was considered to provide an important feeding ground but provided little benefit for breeding purposes.

Magrath (1992) undertook a study specifically of waterbirds of the lower Lachlan and Murrumbidgee valleys. This study included three wetland areas within Yanga National Park, namely Redbank Swamp (including Mercedes and Pococks swamps), Tarwillie Swamp, and Egret Swamp. Redbank Swamp, a river red gum dominated swamp, was found to support sizeable populations of a number of waterbirds, including three egret and two cormorant species, and rufous (nankeen) night heron (Nycticorax caledonicus). It was suggested that the swamp was inundated annually and could support colonies in most years. Tarwillie Swamp was found to have supported one of the largest great egret colonies recorded in Australia. Large colonies of egrets and cormorants were observed on Egret Swamp.

A total of 64 waterbird species from 14 families were recorded by these surveys (Table 17).


Table 16: Major bird surveys in Lowbidgee region which have sites in Yanga National Park

Year Location Totalspecies

Waterbird species Reference Comments

1982 Lowbidgee–Lachlan confluence

114 42 Pressey et al. (1984)

Severe drought in 1982–83

1989–90 Lowbidgee–Lachlan confluence

164 61 Maher (1990) Major flood during 1989 resulting in breeding

1990–91 Lower Lachlan and Murrumbidgee valleys

? Magrath (1992)

This survey was specifically for waterbirds. Major flood occurred during sampling period

1998–99 Redbank District 142 44 Bales (1999) Recorded 15 species that had not been recorded in previous surveys

1983–2008

Lowbidgee floodplain 54 Kingsford and Thomas (2001)

Total species detected in the annual aerial survey

2005–2006

Yanga National Park 36 Maher (2006) Following the release of large volume of EWA. Twelve colonial nesting species were recorded breeding

2008 Lowbidgee 27 Spencer and Allman (2008)

RERP ecological investigation. The majority of the park was dry; a few sites received EWA.

Table 17: Waterbird species recorded in Yanga National Park and surrounding floodplains

Family Common name Scientific name Swamp harrier Circus approximans White-bellied sea eagle Haliaeetus leucogaster

Accipitridae

Whistling kite Haliastur sphenurus Chestnut teal Anas castaneaGrey teal Anas gracilisAustralasian shoveler Anas rhynchotisPacific black duck Anas superciliosaHardhead Aythya australisMusk duck Biziura lobataAustralian wood duck Chenonetta jubataBlack swan Cygnus atratusPlumed whistling duck Dendrocygna eytoniPink-eared duck Malacorhynchus

membranaceusBlue-billed duck Oxyura australisFreckled duck Stictonetta naevosa

Anatidae

Australian shelduck Tadorna tadornoidesAnhingidae Darter Anhinga melanogasterArdeidae Great egret Ardea alba


Family Common name Scientific name Little egret Ardea garzetta Cattle egret Ardea ibis Intermediate egret Ardea intermedia White-faced heron Ardea novaehollandiaePacific heron Ardea pacificaAustralasian bittern Botaurus poiciloptilus Little bittern Ixobrychus minutus Rufous night heron Nycticorax caledonicusBlack-fronted plover Charadrius melanops Red-fneed dotterel Erthrogonys cintus Masked lapwing Vanellus miles

Charadriidae

Banded lapwing Vanellus tricolor Caspian tern Hydroprogne caspiaSilver gull Larus novaehollandiaeWhiskered tern Sterna hybrida

Laridae

Gull-billed tern Sterna niloticaPelecanidae Australian pelican Pelecanus conspicillatus

Great cormorant Phalacrocorax carboLittle pied cormorant Phalacrocorax melanoleucosLittle black cormorant Phalacrocorax sulcirostris

Phalacrocoracidae

Pied cormorant Phalacrocorax variusGreat-crested grebe Podiceps cristatusHoary-headed grebe Poliocephalus poliocephalus

Podicipedidae

Australasian grebe Tachybaptus novaehollandiae Eurasian coot Fulica atra Dusky moorhen Gallinula tenebrosaBlack-tailed native-hen Gallinula ventralisPurple swamphen Porphyrio porphyrioAustralian crake Porzana fluminea Baillon’s crake Porzana pusilla Spotless crake Porzana tabuensis

Rallidae

Buff-banded rail Rallus philippensis Banded stilt Cladorhynchus leucocephalusBlack-winged stilt Himantopus himantopus

Recurvirostridae

Red-necked avocet Recurvirostris novaehollandiaeRostratulidae Painted snipe Rostratula benghalensis

Sharp-tailed sandpiper Calidris acuminate Latham's snipe Gallinago hardwickii Black-tailed godwit Limosa limosa Greenshank Tringa nebularia

Scolopacidae

Marsh sandpiper Tringa stagnatilis Yellow-billed spoonbill Platalea flavipesRoyal spoonbill Platalea regiaGlossy ibis Plegadis falcinellusAustralian white (sacred) ibis Threskiornis aethiopica

Threskiornithidae

Straw-necked ibis Threskiornis spinicollis

Data sources: Pressey et al. (1984); Maher (1990, 2006); Magrath (1992); Bales (1999); Kingsford and Thomas (2001); Spencer and Allman (2008)


5.3.3 Fish

Very little systematic work has been undertaken on the fish in Yanga National Park or surrounding wetlands. Fish were not included in the studies undertaken by Pressey et al. (1984) or Robertson et al. (1994). Maher (1990), whilst predominantly reporting on birds of the Lachlan–Murrumbidgee confluence, referred to fish which were observed during the study. These were European carp (Cyprinus carpio), bony bream (Nematalosa eribi) and mosquito fish (Gambusia affinis). The carp were said to be abundant in all swamps, particularly those used as water storages and in the Lachlan and Murrumbidgee rivers. Bony bream were observed in large numbers in Tala Creek during a period of rising floodwater. Mosquito fish were observed to be common in shallow floodwater (Maher 1990).

A number of fish surveys have been conducted in the Murrumbidgee catchment by NSW Fisheries (cf. Baumgartner 2004; Gilligan 2005). These studies focused on instream habitats and did not include any sites on the Lowbidgee floodplain. Therefore these studies provide little information about fish usage of floodplain habitats.

Bales (1999) sampled a range of fish habitats in Yanga National Park, including small and large irrigation channels, lakes and deep waters, and shallow wetlands. Eight species were recorded; however, the fish community was dominated by introduced species, notably European carp, in all habitats. In addition, two hardy freshwater species – yabby (Cheerax destructor) and long-necked turtle (Chelodina longicollis) – were also abundant in these habitats except the lakes.

As part of the RERP ecological investigation, Spencer and Allman (2008) sampled nine sites (four in Yanga National Park) in the spring breeding season in Lowbidgee including irrigation channels, temporary wetlands, water storages and the Murrumbidgee channel. A total of 12 species (eight native and four introduced) were recorded. Again, the introduced European carp dominated most of the sampled sites.

Table 18 lists all fish species known to occur in Yanga National Park (including the Murrumbidgee channel).

5.3.4 Frogs

Limited historical information is available on frogs in Yanga National Park. Pressey et al. (1984) recorded four species for the Lachlan–Murrumbidgee confluence area: brown froglet (Crinia parinsignifera), spotted-marsh frog (Limnodynastes tasmaniensis),barking marsh frog (Limnodynastes fletcheri) and Peron’s tree frog (Litoria peronii).Based upon knowledge about the general distribution of frog species Pressey et al.(1984) predicted that a further seven species could be expected to occur within the area.

Maher (1990) also recorded a number of frog species. Peron’s tree frog, barking marsh frog and spotted-marsh frog were all recorded in the Redbank Weir area. One individual of the southern bell frog was also recorded in this area.

Robertson et al. (1994), in their study of the Nimmie–Caira system, reported that frogs were abundant at many of the wetter sites investigated. Five species were described as being ‘detected too numerous to tabulate’. These include two species of brown froglet (Crinia signifera, C. parasignifera), spotted marsh frog, barking marsh frog and Peron’s tree frog. A number of southern bell frogs were also located by the authors following extensive searching.


Table 18: Fish species in the Lowbidgee region, including the Murrumbidgee channel

Family Scientific name Common name Clupeidae Nematalosa erebi Bony bream Galaxiidae Galaxias brevipinnis ^ Climbing galaxias Retropinnidae Retropinna semoni Australian smelt Plotosidae Tandanus tandanus + Freshwater catfish

Craterocephalus fluviatilis + Murray hardyhead Atherinidae Craterocephalus stercusmuscarum fulvus Unspecked hardyhead

Melanotaeniidae Melanotaenia fluviatilis + Murray–Darling rainbowfish Macquaria ambigua ambigua Golden perch Percichthyidae Maccullochella peelii peelii + Murray cod Bidyanus bidyanus Silver perch Terapontidae Leiopotherapon unicolor Spangled perch Philypnodon grandiceps Flat-headed gudgeon Eleotridae Hypseleotris spp Western carp gudgeon Cyprinus carpio * Carp Cyprinidae Carassius auratus * Goldfish

Cobitidae Misgurnus anguillicaudatus * Oriental weatherloach Poecilidae Gambusia holbrooki* Eastern gambusia Percidae Perca fluviatilis * Redfin perch

* Exotic species, + Likely to be locally extinct., ^ trans-located native species. Data sources: Bales (1999); Baumgartner (2004); Gilligan (2005); Spencer and Allman (2008)

Bales (1999) recorded 10 species in Yanga National Park. Brown froglet (Criniasloanei), eastern pobblebonk (Limnodynastes dumerilii), painted burrowing frog (Neobatrachus sudelli) and desert tree frog (Litoria rubella) were not reported by the above surveys.

Although targeting the endangered southern bell frog, Wassens et al. (2008a) recently recorded six frog species in Yanga National Park; the giant banjo frog (Limnodynastes interioris) has not been reported before.

A search of the Atlas of NSW Wildlife for Yanga National Park produced a record of eight frog species. Collating all the records, a total of 12 species from three families has been recorded in Yanga National Park (Table 19).

The southern bell frog was once widespread and abundant throughout south-eastern Australia (Wassens et al. 2008b). Since the early 1980s its population and distribution have been reduced to a critical level (Lunney et al. 2000) and, for this reason, it is listed as endangered on the schedules of the TSC Act.

In the Lowbidgee, the southern bell frog occupies two different habitats: river red gum forest and black box/lignum woodland (Bales 1999; Wassens 2008b). In river red gum swamps in Yanga National Park the species is associated with emergent macrophytes such as tall spike rush (Eleocharis sphacelata) and water primrose (Ludwigiapeploides). In contrast, the black box/lignum wetlands within the Nimmie–Caira system contain abundant floating and submerged macrophytes such as nardoo (Marsileadrummondii) and common milfoil (Myriophyllum variifolium) (Wassens et al. 2008a). As there is no long-term monitoring data, it is not clear exactly when southern bell frog populations began to decline within the Lowbidgee. However, like many amphibians, the southern bell frog is thought to be particularly vulnerable to habitat loss and fragmentation (Wassens et al. 2008b).


5.3.5 Reptiles

Only limited studies have been undertaken that cover the reptiles of Yanga National Park. Pressey et al. (1984) recorded reptiles as part of their survey of the wetlands of the Lachlan–Murrumbidgee confluence. As part of a flora and fauna survey for Redbank Riparian Landcare group, Bales (1999) targeted likely habitats such as tree hollows, under logs, woody debris and tree bark. Eighteen species, including four geckos, two goannas, two dragons, five skinks, two snakes and two turtles, were sampled in this survey.

Combining all records including those in the Atlas of NSW Wildlife, a total of 24 reptile species have been recorded as occurring in Yanga National Park and its surroundings (Table 20).

5.3.6 Mammals

Information for mammals in Yanga National Park is scattered and limited. Some information is available from a number of studies which have been undertaken on the wetlands of the Murrumbidgee–Lachlan confluence. These include Pressey et al. (1984) and Robertson et al. (1994). Mammals were included in the Redbank flora and fauna survey by Bales (1999). Recently, a total of 11 bat species was recorded in a bat survey in Yanga National Park (M Pennay 2009, pers. comm.). Table 21 presents a list of 33 (seven introduced) mammal species that were recorded in these surveys and species recorded in the Atlas of NSW Wildlife.

Table 19: Frog species in Yanga National Park and surrounding floodplains

Family Scientific name Common name Reference

Crinia parinsignifera Eastern sign-bearing froglet 1, 3, 4, 5, 6 Crinia signifera Common eastern froglet 3, 4, 5 Crinia sloanei Sloane's froglet 4 Limnodynastes dumerilii Eastern banjo frog 4, 5 Limnodynastes fletcheri Long-thumbed frog 1, 2, 3, 4, 5, 6 Limnodynastes interioris Giant banjo frog 6 Limnodynastes tasmaniensis Spotted grass frog 1, 2, 3, 4, 5, 6

Myobatrachidae

Pseudophryne bibronii Bibron's toadlet 5 Neobatrachus Neobatrachus sudelli Burrowing frog 4,

Litoria peronii Peron's tree frog 1, 2, 3, 4, 5, 6 Litoria raniformis Southern bell frog 2, 3, 4, 5, 6

Hylidae

Litoria rubella Desert tree frog 4

Data sources: 1: Pressey et al. (1984); 2: Maher (1990); 3: Robertson et al. (1994); 4: Bales (1999); 5: Atlas of NSW Wildlife; 6: Wassens et al. (2008a)


Table 20: Reptiles recorded in Yanga National Park and surrounding floodplains

Family Scientific name Common name Pygopodidae Aprasia inaurita Mallee worm lizard

Chelodina longicollis Eastern long-necked turtle Chelidae Emydura macquarii Murray turtle Christinus marmoratus Marbled gecko Diplodactylus tessellatus Tessellated gecko Underwoodisaurus milii Thick-tailed gecko Gehyra variegata Tree dtella

Gekkonidae

Strophurus intermedius Southern spiny-tailed gecko Pogona barbata Bearded dragon Agamidae Pogona vitticeps Central bearded dragonVaranus gouldii Gould's goanna Varanidae Varanus varius Lace monitor Ctenotus atlas Southern mallee ctenotus Cryptoblepharus carnabyi Spiny-palmed shinning-skink Egernia striolata Tree skink Lerista muelleri Wood mulch-slider Lerista punctatovittata Eastern robust slider Morethia boulengeri South-eastern morethia skink

Scincidae

Tiliqua rugosa Shingle-back Echiopsis curta Bardick Notechis scutatus Tiger snake Pseudechis porphyriacus Red-bellied black snake Pseudonaja textilis Eastern brown snake

Elapidae

Suta suta Curl snake

Data sources: Pressey et al. (1984); Maher (1990); Bales (1999); Atlas of NSW Wildlife


Table 21: Mammal species in Yanga National Park and surroundings

Family Scientific name Common name Canidae Vulpes vulpes * European red fox Cervidae Cervus elaphus * Red deer

Dasyurus maculatus Spotted-tailed quoll Sminthopsis crassicaudata Fat-tailed dunnart

Dasyuridae

Sminthopsis murina Common dunnart Felidae Felis catus * Feral cat

Lepus capensis * Brown hare Leporidae Oryctolagus cuniculus * Rabbit Macropus fuliginosus Western grey kangaroo Macropus giganteus Eastern grey kangaroo

Macropodidae

Macropus rufus Red kangaroo Molossidae Mormopterus planiceps Little mastiff-bat

Hydromys chrysogaster Water-rat Mus musculus * House mouse

Muridae

Notomys mitchellii Mitchell's hopping-mouse Peramelidae Chaeropus ecaudatus Pig-footed bandicoot

Trichosurus sp. Brushtail possum Phalangeridae Trichosurus vulpecula Common brushtail possum

Suidae Sus scrofa * Feral pig Tachyglossidae Tachyglossus aculeatus Short-beaked echidna

Chalinolobus gouldii Gould's wattled bat Chalinolobus morio Chocolate wattled bat Nyctophilus geoffroyi Lesser long-eared bat Nyctophilus gouldi Gould’s long-eared bat Scotorepens balstoni Inland broad-nosed bat Myotis Macropus Large-footed myotis (fishing bat) Eptesicus vulturnus Small forest eptesicus Vespadelus darlingtoni Large forest bat Vespadelus regulus Southern forest bat

Vespertilionidae

Vespadelus vulturnus Little forest bat Mormopterus ridei Eastern freetail bat Mormopterus ‘species 4’ Southern freetail bat

Molossidae

Austronomus australis White-striped freetail bat

Data sources: Pressey et al. (1984); Robertson et al. (1994); Bales (1999); Atlas of NSW Wildlife, M Pennay (2009, pers. comm.)

* Introduced species


6 Critical ecosystem processes Ecosystem processes are the physical, chemical and biological actions or events that link organisms and their environment. They include decomposition, production, nutrient cycling and fluxes of nutrients and energy (MEA 2005). Rather than describing all ecosystem processes (an impractical task), this section will focus on those critical processes that most strongly influence or determine the ecological character of Yanga National Park, in particular hydrological and geomorphologic processes.

6.1 Hydrological processes

The ‘flood pulse’, a term used for the floodwater input to floodplains, is commonly perceived as the main factor that controls the existence and productivity of floodplain ecosystems of major world rivers (Junk et al. 1989; Junk 1997; Lewis et al. 2000). In the Lowbidgee, where evaporation greatly exceeds rainfall, floodwater is vital to sustain functioning ecosystems in the floodplain, and the inundation regime (extent, frequency, duration and timing) is the governing process for other critical processes (Figure 30).

In Yanga National Park the natural inundation regime is primarily governed by flow in the Murrumbidgee River. However, the construction of Redbank and Maude weirs in 1939 and the subsequent introduction of the Lowbidgee FCID in the 1940s greatly modified the distribution and retention of water within the floodplain resulting in smaller inundated areas with longer residence time (Table 22).

6.1.1 Natural overbank flows

Yanga National Park experiences natural flooding during high flows. Kingsford and Thomas (2001) provided a detailed description of how overbank flows disperse in the Lowbidgee floodplain, as cited below.

Overbank flows are distributed throughout the floodplain by a series of distributaries (Fiddlers, Uara, Caira, Nimmie, Pollen, Waugorah, Talpee, Monkem, Kietta, Yanga, Paika and other unnamed small creeks), which form a highly complex interconnected network of braided creeks on the Lower Murrumbidgee floodplain. Most of these convey water to the south but some small creeks also take water to the north where the Lachlan River terminates in the Great Cumbung Swamp. Flows from the Lachlan River rarely reach the Murrumbidgee River except in major floods. Flows leave the Murrumbidgee River first at Fiddlers Creek (previously known as Gum Creek). This creek system is shallow and provided water to the south. The floodplain of this creek system includes Yanga Nature Reserve (1772 ha), an area recognised for its stands of Black Box woodland. Anastomosing channels of Fiddlers Creek eventually form the Uara Creek that forms a channel and conveys water to Yanga Lake and the Murrumbidgee River near the town of Balranald. The next creeks to leave the Murrumbidgee River are the Caira and Nimmie Creeks that also convey water to the southwest. Neither has well defined channels from the river. The river used to flow over the banks to these systems of anastomosing channels. Water from the Caira Creek flowed south before bifurcating to the north to form Pollen Creek and to the south to continue as Caira Creek. Nimmie Creek water joined up with Pollen Creek but also flowed to the northwest to inundate areas near the river. Between Nimmie Creek and Waugorah Creek, conveying water to the south, smaller channels take water to the floodplain. Waugorah Creek flows southwest to fill channels and floodplains and links up with Monkem and Talpee Creeks that similarly flow to the south to join up with the main channel of the Murrumbidgee River. The Murrumbidgee River also has many small channels that convey water to the south. North and west of the Murrumbidgee River, the Redbank system is a large floodplain dissected by channels with no defined distributary creeks. This area is primarily reliant on overbank flows caused by a constriction in the main channel capacity of the river.


Flood regimes (time, frequency and duration) and patterns (spatial distribution of the water) in the Lowbidgee floodplain have changed dramatically due to upstream development as well as the management of the Lowbidgee Scheme (Table 23; Eddy 1992; Kingsford 2003; Page et al. 2005). Kingsford (2003) summarised the development of the area since European settlement and distinguished three major periods: before 1912, 1939–80, and after 1980 when most of the development was completed. As flow records are available only after 1936 for both Maude and Redbank gauging stations, the natural flow regime (i.e. before 1912) for the Lowbidgee floodplain cannot be restructured without complicated modelling. However, comparison of river discharges before and after 1970 (1937–70 and 1971–2007) downstream of Redbank Weir(Figure 31) indicates that the frequency of overbank flow decreased by more than 50%,

Table 22: Hydrological processes in Yanga National Park

Process Description

Overbank flows

Overbank flow is an infrequent, high-flow event that breaches riverbanks. Overbank flow occurs when river discharge reaches 7500 ML/day, 9500 ML/day and 20,000 ML/day at Balranald, Redbank Weir and Maude Weir, respectively. The Lowbidgee was flooded naturally in 15–20% of the years before European settlement (Pressey et al. 1984). As the hydrological records at Redbank and Maude weirs began in the late 1930s, the pattern of natural overbank flow cannot be restructured without complicated modelling. Nevertheless, the investigation of available river discharge records (1937–2007) at Redbank Weir reveals that while the median duration of floods (defined as the consecutive days of overbank flow) has not changed significantly, the frequency of overbank flow at Redbank Weir has been halved from 18.5% (1937–70) to less than 9% (1970–2007) (Wen et al.2009). Furthermore, Yanga National Park has not experienced natural overbank flow since 1997 (Wen et al. 2009).

Artificial watering (including environ-mental water allocation)

To compensate the reduction in natural overbank flows due to upstream water extraction that resulted in a decrease in agricultural productivity, Maude and Redbank weirs were constructed primary for diverting water (’surplus flow’) to the Lowbidgee FCID. Surplus flows to Yanga National Park are primarily via Yanga regulator, and the delivery of water follows the natural network of waterways with relatively minor assistance or guidance from constructed channels or levees. The volume of diversion depends on the available flow in the Murrumbidgee and on climatic conditions with a median of 38.7 GL/yr (Figure 31), and the timing of diversion generally follows the demand for agriculture (autumn and winter).

Rainfall and evaporation

Rainfall in Lowbidgee is highly erratic with slightly more rainy days and higher rainfall in winter (Figure 5, section 2.2). Evaporation is high, ranging from 190 to 200 cm/yr.

Groundwater exchange

There is no detailed study investigating the interactions between surface water and groundwater. A study conducted for the river reach between Hay and Maude estimated high transmission loss (0.5% per km) (WRC 1982) suggesting a high rate of groundwater recharge. However, the recorded river discharges at Maude and Balranald suggest a much lower loss at this reach. The topsoil (to 1 m) at Yanga National Park has low saturated hydraulic conductivity (less than 2 mm/hr), except for the higher ground, less flooded, areas (EAS 2008).


Riv

er h

ydro

grap

h

Ban

k fu

ll le

vel

Floo

d se

ason

Dry

sea

son

Floo

dpla

in fo

rest

and

woo

dlan

ds

1.W

ater

and

ass

ocia

tes

mat

eria

l (d

ispo

res,

sed

imen

t, nu

trie

nt)

inpu

ts

2.Te

rres

tria

l fau

na e

scap

e or

dr

owne

d or

pre

yed

3.N

utrie

nt re

leas

e fr

om li

ve

unde

rsto

rey

vege

tatio

n, li

tter a

nd

tops

oil

4.Pr

imar

y pr

oduc

tion

boom

s 5.

Rec

harg

ing

aqui

fers

Upw

ard

limb

Dow

nwar

d Li

mb

Con

nect

ed to

rive

r and

flo

odpl

ain

1.O

rgan

ic m

atte

r exp

orts

Fi

shes

mov

e to

rive

r2.

Peak

phy

topl

ankt

on g

row

th3.

Plan

kton

, aqu

atic

pla

nt

inve

rteb

rate

drif

t to

river

4.A

bund

ance

of w

ater

bird

re

ache

s m

axim

um5.

Col

onia

l wat

erbi

rd

bree

ding

com

plet

ed.

6.Fl

edge

d yo

ung

feed

in

surr

ound

ing

flood

plai

n

Lake

s an

d w

etla

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Con

nect

ed to

rive

r and

floo

dpla

in1.

Nut

rient

, sed

imen

t and

org

anic

m

atte

r inp

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Seed

/egg

ban

k em

erge

3.

Rap

id g

row

th o

f aqu

atic

pla

nts

and

inve

rteb

rate

s 4.

Fish

es e

nter

, spa

wn,

and

rapi

dly

grow

on

floo

dpla

in

5.N

umbe

r of w

ater

bird

s in

crea

se a

s fo

od s

ourc

es in

crea

se6.

Larg

e flo

od e

vent

s in

itiat

e co

loni

al w

ater

bird

bre

edin

g

Riv

ers

and

anab

ranc

hes

1.Fo

rmat

ion

of v

arie

ty o

f site

s w

ith d

iffer

ent s

edim

ent t

ypes

(e

.g. f

ine

and

coar

se, o

rgan

ic d

ebris

) pro

vidi

ng v

arie

d ni

ches

fo

r reg

ener

atio

n 2.

Reg

ener

atio

n of

tree

(e.g

. Riv

er re

d gu

m)

3.W

ater

tabl

es re

cede

4.Se

edlin

g es

tabl

ishm

ent

5.En

croa

chm

ent a

nd c

olon

isat

ion

of te

rres

tria

l gra

ss s

peci

es

6.Es

tabl

ishm

ent o

f ter

rest

rial f

auna

pop

ulat

ion

7.A

ccum

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of o

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atte

r as

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imal

was

te, a

nd

tops

oil

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ated

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al/p

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anen

t aqu

atic

hab

itats

1.W

ater

leve

l dec

reas

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pora

tion

and

grou

ndw

ater

in

filtr

atio

n2.

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rient

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inity

, tur

bidi

ty in

crea

se3.

Con

cent

ratio

n of

org

anis

ms

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ying

and

avi

an p

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of th

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rand

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sh

5.In

crea

se in

alg

al a

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ance

and

drif

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spec

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com

posi

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6.Pr

edat

ion

and

com

petit

ion

amon

g bi

ota

incr

ease

7.R

ezon

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of v

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mm

unity

8.A

quat

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vert

ebra

tes

eith

er fi

nd re

fuge

or g

o on

per

sist

ent

stag

es (e

gg b

ank)

9.W

ater

bird

s di

sper

se to

oth

er w

etla

nds;

oth

er a

reas

with

gr

eate

r pre

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sour

ces

10.L

imite

d w

ater

bird

bre

edin

g. R

ooke

ries

usua

lly s

mal

l and

co

nfin

ed to

per

man

ent w

ater

hole

s11

.Con

solid

atio

n of

sed

imen

t

Con

fined

to c

hann

els

1.M

ain

mat

eria

l inp

uts

from

ups

trea

m2.

May

con

nect

to th

e flo

odpl

ain

thro

ugh

subs

urfa

ce fl

ow.

Con

nect

ed to

floo

dpla

in1.

Fish

and

pla

nt p

ropa

gule

sen

ter f

lood

plai

n.2.

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rient

, org

anic

mat

ter (

fine/

coar

se/la

rge

woo

d de

bris

) and

oth

er

mat

ters

(e.g

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t) e

nter

rive

r 3.

Fish

and

inve

rteb

rate

s m

ove

from

floo

dpla

in to

rive

r 4.

Smal

l num

bers

of w

ater

bird

s ro

ost a

nd fe

ed a

long

cha

nnel

edg

e.

1.W

ater

flow

s ba

ck to

rive

r 2.

Coa

rse

mat

eria

ls (l

itter

), di

ssol

ved

nutr

ient

(DO

C, N

, P)

, and

sal

ts e

xpor

t to

river

3.Fi

sh a

nd o

ther

aqu

atic

fa

una

mov

e to

rive

r4.

Sedi

men

t exp

orts

to ri

ver

as b

ank

and

soil

eros

ion

5.M

aint

ain

high

pro

duct

ivity

6.R

echa

rgin

g aq

uife

rs

Riv

er h

ydro

grap

h

Ban

k fu

ll le

vel

Floo

d se

ason

Dry

sea

son

Floo

dpla

in fo

rest

and

woo

dlan

ds

1.W

ater

and

ass

ocia

tes

mat

eria

l (d

ispo

res,

sed

imen

t, nu

trie

nt)

inpu

ts

2.Te

rres

tria

l fau

na e

scap

e or

dr

owne

d or

pre

yed

3.N

utrie

nt re

leas

e fr

om li

ve

unde

rsto

rey

vege

tatio

n, li

tter a

nd

tops

oil

4.Pr

imar

y pr

oduc

tion

boom

s 5.

Rec

harg

ing

aqui

fers

Upw

ard

limb

Dow

nwar

d Li

mb

Con

nect

ed to

rive

r and

flo

odpl

ain

1.O

rgan

ic m

atte

r exp

orts

Fi

shes

mov

e to

rive

r2.

Peak

phy

topl

ankt

on g

row

th3.

Plan

kton

, aqu

atic

pla

nt

inve

rteb

rate

drif

t to

river

4.A

bund

ance

of w

ater

bird

re

ache

s m

axim

um5.

Col

onia

l wat

erbi

rd

bree

ding

com

plet

ed.

6.Fl

edge

d yo

ung

feed

in

surr

ound

ing

flood

plai

n

Lake

s an

d w

etla

nds

Con

nect

ed to

rive

r and

floo

dpla

in1.

Nut

rient

, sed

imen

t and

org

anic

m

atte

r inp

ut2.

Seed

/egg

ban

k em

erge

3.

Rap

id g

row

th o

f aqu

atic

pla

nts

and

inve

rteb

rate

s 4.

Fish

es e

nter

, spa

wn,

and

rapi

dly

grow

on

floo

dpla

in

5.N

umbe

r of w

ater

bird

s in

crea

se a

s fo

od s

ourc

es in

crea

se6.

Larg

e flo

od e

vent

s in

itiat

e co

loni

al w

ater

bird

bre

edin

g

Riv

ers

and

anab

ranc

hes

1.Fo

rmat

ion

of v

arie

ty o

f site

s w

ith d

iffer

ent s

edim

ent t

ypes

(e

.g. f

ine

and

coar

se, o

rgan

ic d

ebris

) pro

vidi

ng v

arie

d ni

ches

fo

r reg

ener

atio

n 2.

Reg

ener

atio

n of

tree

(e.g

. Riv

er re

d gu

m)

3.W

ater

tabl

es re

cede

4.Se

edlin

g es

tabl

ishm

ent

5.En

croa

chm

ent a

nd c

olon

isat

ion

of te

rres

tria

l gra

ss s

peci

es

6.Es

tabl

ishm

ent o

f ter

rest

rial f

auna

pop

ulat

ion

7.A

ccum

ulat

ion

of o

rgan

ic m

atte

r as

litte

r, an

imal

was

te, a

nd

tops

oil

Isol

ated

eph

emer

al/p

erm

anen

t aqu

atic

hab

itats

1.W

ater

leve

l dec

reas

es d

ue to

eva

pora

tion

and

grou

ndw

ater

in

filtr

atio

n2.

Nut

rient

, sal

inity

, tur

bidi

ty in

crea

se3.

Con

cent

ratio

n of

org

anis

ms

4.D

ying

and

avi

an p

reda

tion

of th

e st

rand

ed fi

sh

5.In

crea

se in

alg

al a

bund

ance

and

drif

t in

spec

ies

com

posi

tion

6.Pr

edat

ion

and

com

petit

ion

amon

g bi

ota

incr

ease

7.R

ezon

ing

of v

eget

atio

n co

mm

unity

8.A

quat

ic in

vert

ebra

tes

eith

er fi

nd re

fuge

or g

o on

per

sist

ent

stag

es (e

gg b

ank)

9.W

ater

bird

s di

sper

se to

oth

er w

etla

nds;

oth

er a

reas

with

gr

eate

r pre

y re

sour

ces

10.L

imite

d w

ater

bird

bre

edin

g. R

ooke

ries

usua

lly s

mal

l and

co

nfin

ed to

per

man

ent w

ater

hole

s11

.Con

solid

atio

n of

sed

imen

t

Con

fined

to c

hann

els

1.M

ain

mat

eria

l inp

uts

from

ups

trea

m2.

May

con

nect

to th

e flo

odpl

ain

thro

ugh

subs

urfa

ce fl

ow.

Con

nect

ed to

floo

dpla

in1.

Fish

and

pla

nt p

ropa

gule

sen

ter f

lood

plai

n.2.

Nut

rient

, org

anic

mat

ter (

fine/

coar

se/la

rge

woo

d de

bris

) and

oth

er

mat

ters

(e.g

. sal

t) e

nter

rive

r 3.

Fish

and

inve

rteb

rate

s m

ove

from

floo

dpla

in to

rive

r 4.

Smal

l num

bers

of w

ater

bird

s ro

ost a

nd fe

ed a

long

cha

nnel

edg

e.

1.W

ater

flow

s ba

ck to

rive

r 2.

Coa

rse

mat

eria

ls (l

itter

), di

ssol

ved

nutr

ient

(DO

C, N

, P)

, and

sal

ts e

xpor

t to

river

3.Fi

sh a

nd o

ther

aqu

atic

fa

una

mov

e to

rive

r4.

Sedi

men

t exp

orts

to ri

ver

as b

ank

and

soil

eros

ion

5.M

aint

ain

high

pro

duct

ivity

6.R

echa

rgin

g aq

uife

rs

Fi

gure

30:

R

elat

ions

hips

bet

wee

n hy

drol

ogic

al c

ycle

and

oth

er fl

oodp

lain

eco

logi

cal p

roce

sses

und

er a

nat

ural

floo

d re

gim

e


from about 18.5% to less than 9%. The year 1970 (rather than 1980 as in Kingsford and Thomas 2004) was chosen as a benchmark because the reduction of river discharge at Hay became significant only after the late 1960s (Wen 2009). The dramatic decrease in the frequency of overbank flows may be the single most important factor contributing to the continuous deterioration of river red gum condition in Yanga National Park.

There have been dramatic changes in hydrology downstream of Redbank Weir since 1970 (Figure 31). The annual median flow decreased by more than 60% from 2727.0 ML/day to 1048.5 ML/day (Table 24), with a reduction observed for every month. The biggest reduction (up to 90%) is in November, when the natural spring peak flow occurs. The peak flows are in September, when the demand for irrigation is at its lowest.

Table 23: Major developments on the Murrumbidgee River 1855–1982

Period Development Relevant particulars 1855–1902

Deepening of Yanco Creek opening to increase water diversions from the Murrumbidgee

1880–present

River pumps used to take water from the Murrumbidgee for irrigation, town water supply, domestic and livestock use

During 1979–90, an average 301.6 GL was taken annually for irrigation, 36.0 GL for other uses.

1907–27 Burrinjuck Dam stage 1 Total capacity of 951.9 GL 1912–27 MIA developed Receives up to 780 GL per year diverted

from the Murrumbidgee River; licensed irrigation area about 150,000 ha.

1914–57 Burrinjuck Dam stage 2, capacity increased by 400 GL

Total capacity of Burrinjuck Dam is 1026 GL; first supply water to MIA in 1912. From 1979–90, annual mean division is 1143.5 GL.

1928 Yanco weir constructed Capacity of diverting 700 ML/day to irrigation areas and properties along Yanco Creek

1936–40 Maude Weir constructed Diverts water to Lowbidgee Irrigation Area. Mean annual diversion (1970–82) is 100.4 GL.

1937–40 Redbank Weir constructed Diverts water from the Murrumbidgee to Lowbidgee Irrigation Area. Mean annual diversion (1970–82) is 77.7 GL.

1956– 62 Main expansion of Coleambally Irrigation Area

Received up to 600 GL per year from Murrumbidgee River. Licensed irrigation area approximately 80,000 ha.

1958–68 Snowy–Tumut Hydroelectricity Scheme

Diverts up to 600 GL per year from Snowy River to Tumut River

1965–68 Blowering Dam built Capacity 1626.0 GL, storing water diverted from the Snowy River system and regulating flow in Tumut River

1982 Hay Weir constructed Capacity 13.5 GL. Mean annual division (1979–90) is 7.7 GL.

Data sources: DWR (2001); Pressey et al. (1984); Kingsford and Thomas (2001)


Both the 30-day maximum and minimum flows decreased, and the duration and frequency of extreme low flows increased 33.3% and 300%, respectively. One direct impact of the decreased flow is the reduction of floodplain inundation, which depends on the overbank flows. The frequency of bankfull river discharge declined by 53.0% from 18.5% to 8.7% (Table 24), which may be the single most important factor contributing to the continuous deterioration of river red gum condition in Yanga National Park.

Table 24: Changes in selected hydrological indicators in the Murrumbidgee downstream of Redbank Weir

Indicator * 1936–70 1971–2007 Change (%)

Annual median flow (ML/day) 2727.0 1048.5 –61.6 30-day maximum flow (ML/day) 10,368.0 7430.4 –28.3 30-day minimum flow (ML/day) 691.2 259.2 –62.5 Extremely low flow^ duration (days/yr) 7.5 10.0 33.3 Extremely low flow frequency 1.0 4.0 300.0 Rate of change (m3/s/day) 1.6 0.6 –62.5Frequency of bankfull flows (%) 18.5 8.7 –53.0

Data source: Wen et al. (2009)* Median values except for overbank flow frequency ^ Flows fall below the 10% percentile during the corresponding period

Monthly flow distribution at downstream of Redbank Weir

0

50

100

150

200

250

Jan Feb Mar Apr May Jun Jul Aug Sep Oct Nov Dec

Mea

n m

onth

ly fl

ow (G

L/da

y)

Before After

Data source: Wen et al. (2009)

Figure 31: Monthly flow distribution before and after 1970


6.1.2 Artificial watering

Following the completion of Redbank and Maude weirs, surplus river flows were diverted to Yanga National Park through three pathways (Figure 32): a) Yanga regulator, where the majority of diversions to Yanga take place, b) Waugorah regulator, c) the Nimmie–Caira FCID. The distribution of water within Yanga National Park is primarily overland flow, following natural flood runners. The diversion from Nimmie–Caira FCID (via Maude) fills Tala Lake (a major irrigation storage, part of which is in Yanga National Park) via Talpee Creek. The historical records of diversion to Yanga National Park through Yanga and Waugorah regulators (Figure 30) were estimated by eye, thus only provided a best guess for water supply to the floodplain.

Murrum

bidgee River

WaugorahBlock

Irrigation Block

Yanga CropRedbank

/NarrockweelBlock

Piggery LakeBlock

BreerSwamp

Block

TarwillieSwamp

Block

Creek BreerBlock

Tala Creek

Yanga Creek

TalpeeC

reek

TalaLake

South Tala Block

Uara Block

YangaLake

Nim

mie-C

airaFlood And Irrigation district

WaugorahRegulator

Yanga Regulator

Woolshed Regulator

NunkungerieRegulator

BreerRegulator

White Elephant Channel

MonkenCreek

Deadman’sCreek

Bottle GateCreek

Pee VeeCreek

KieetaRegulator

Redbank Weir

Balranald Weir

Channel flow

Overland flow

Floodplain

Ephemeral Waterbody

Murrum

bidgee River

WaugorahBlock

Irrigation Block

Yanga CropRedbank

/NarrockweelBlock

Piggery LakeBlock

BreerSwamp

Block

TarwillieSwamp

Block

Creek BreerBlock

Tala Creek

Yanga Creek

TalpeeC

reek

TalaLake

South Tala Block

Uara Block

YangaLake

Nim

mie-C

airaFlood And Irrigation district

WaugorahRegulator

Yanga Regulator

Woolshed Regulator

NunkungerieRegulator

BreerRegulator

White Elephant Channel

MonkenCreek

Deadman’sCreek

Bottle GateCreek

Pee VeeCreek

KieetaRegulator

Redbank Weir

Balranald Weir

Channel flow

Overland flow

Floodplain

Ephemeral Waterbody

Channel flow

Overland flow

Floodplain

Ephemeral Waterbody

Based on Clarkson (2000)

Figure 32: Irrigation water distribution pattern in Yanga National Park


Over the years a complex bank system has been developed in Yanga National Park to maximise the value of diverted water for livestock. For example, Piggery Lake was artificially divided into three sections with different water levels separated by banks and broad spillways. Other significant alterations include banking up water in Tala Lake with a weir, diverting water to Yanga Lake by blocking the effluent channel, and stopping southern flow from Tala Lake by the Woolshed regulator.

As there is no volumetric allocation for Lowbidgee FCID, the district is dependent on unregulated flows in the Murrumbidgee for water diversion. There is a marked seasonal pattern in the operation of Redbank Weir, most diversions being made in the late winter and early spring months reflecting crop water requirements. Large variations occur from year to year (Figure 33) as the operations depend on natural flooding, the available water and, to lesser degree, local rainfall. The values were a ‘best guess’ by Department of Water and Energy staff.

In 2007, a gauge was installed at the Yanga regulator to record the environmental flow allocations into Yanga National Park as part of the RERP subprogram Better use of environmental water. The gauge will improve the accountability of environmental water usage.

6.2 Geomorphologic processes Geomorphologic processes are key drivers of floodplain ecology. Sediment erosion and deposition and episodic avulsion are dominant geomorphologic processes within lowland floodplains.

6.2.1 SedimentationSediments are mineral particles that are transported by flowing water. These typically include fine silts, coarser sands, gravels and larger cobbles that are progressively eroded and transported by flowing water. During floods, sediments enter and deposit on the floodplain (Figure 34) and create a variety of geomorphic features which provide principal nursery sites for colonisation by riparian plants.

Annual diversions to Yanga

0

20

40

60

80

100

120

140

160

81/8

2

82/8

3

83/8

4

84/8

5

85/8

6

86/8

7

87/8

8

88/8

9

89/9

0

90/9

1

91/9

2

92/9

3

93/9

4

94/9

5

95/9

6

96/9

7

97/9

8

98/9

9

99/0

0

00/0

1

01/0

2

02/0

3

03/0

4

04/0

5

05/0

6

06/0

7

Water Year

GL

Data source: DWE operational data

Figure 33: Water diverted to Yanga National Park from the Murrumbidgee River


Different sediments provide different physical properties, including the capacity to retain water, which is essential to sustain vegetation in semi-arid regions. Fine sediments drain more slowly and have increased capillarity – the capacity to draw water upwards to create a moist zone above the water table (the capillary fringe). This unsaturated zone is especially important for providing water to floodplain plants and the extent of the capillary fringe varies substantially with sediment texture (particle size), ranging from being only a few centimetres above coarse gravel to more than a metre above silty-sand (Hughes 2003). Therefore, as well as being critical for the formation of new nursery sites, alluvial sediments are also critical for the retention and provision of moisture during dry periods.

Sedimentation processes in the river-floodplain system

Geomorphic features formed from valley sediments are diverse, but some are common to all river systems. Their development can be associated with general links between sediment storage sites and erosion processes that occur within floodplain and channel areas, as shown in Figure 34 and described below.

Gradually accumulated rock and soil (colluviums) and mass-movement deposits are generally located at the valley margins. These sediments are put in motion by sheets of running water (sheet erosion). Depending on the local topography, the sediments move slowly over gradual slopes (soil creep), and rapidly over steep terrain (debris slides and flows), and are carried to the floodplain, channel margin, or stream channel. Deposits on the floodplain (overbank deposits) have various forms such as vertical build-up (vertical accretion) and local, fan-shaped slopes (splays). This area may be eroded by slides cutting into banks (slide-scarp erosion), gradual slides of a wider expanse of land (slide-sheet erosion), or debris slides and flows that move sediments to the channel margin during floods. Point and marginal bars (lateral accretion deposits) are formed in the channel margin. These sediments enter the channel by erosion of gully walls or stream banks. The sediments may accumulate in the channel (channel fills), be deposited and resuspended (transitory channel deposits), or form sand bars and islands when the deposit is not so transitory (lag deposits). Sediments may be taken up again by erosion of the stream bed or island banks and redeposited in the channel margin or in the floodplain as overbank deposits.

Sediment sources

In terms of geomorphology, the Murrumbidgee catchment can be divided into three distinct regions (Figure 35): the upper, middle and lower Murrumbidgee (Olley and Scott 2002, p 1994). The hilly upper region is the principal area from which dissolved solids and sediments are derived. However, the two large dams, Blowering and Burrinjuck, effectively cut off the upper catchment from the middle and lower river, and trap most of the sediment (Murray et al.1992; Olley and Scott 2002). The middle catch-ment is featured by undulating terrain dissected by numerous gully networks (Olley and Wasson 2003). Most of the major tributaries join the Murrumbidgee in this region (Olley and Scott 2002). This is the major source of fine-grained sediment transported to the lower Murrumbidgee (Olive et al. 1994). There is essentially no input (runoff, therefore suspended solids) from the catchment downstream of Wagga Wagga (Murray et al. 1992). Bank erosion is the main process contributing to in-stream turbidity in this region. While 15% of bank length was considered as unstable between Berembed Weir and Hay, it was estimated that 8% of bank length was classified as unstable downstream of Hay (DLWC 1995). Bed mobilisation in this reach is of little significance except at weirs where downstream scouring occurs over short distances (DWLC 1995).


Boxes contain storage locations with example sediments and erosion processes. Arrows represent the links between the various storage sites largely driven by water movement and gravity.

Figure 34: Sediment erosion and deposition processes in the river–floodplain system

From Olley and Scott (2002)

Figure 35: The three geomorphic regions of the Murrumbidgee catchment


Along the river reach from Hay to Balranald, bank erosion occurs as a result of meander movement. When water recedes, bank slumping contributes a major proportion of sediment in the river.

River regulation, such as the construction and operation of dams and weirs, has an inevitable impact on sedimentation patterns and thus on the water retention capacity of the floodplain. All but the finest sediments settle out in the slow-moving reservoirs and weir-pools and, consequently, the released water is typically depleted of sediments and sometimes referred to as ‘hungry water’. Without sediment transport, the riparian zones and floodplains downstream of major dams and weirs lack areas of sediment deposition and new nursery sites become deficient. Further, the sediment-depleted outflow water has substantial capacity to erode and remove the sediments that were present. Over time there is the progressive depletion of alluvial sediments with corresponding loss in suitability for floodplain vegetation and reduction in primary productivity as well.

Few data exist to quantify sediment dynamics within the Lowbidgee floodplains, partly due to the episodicity of transport events and, more importantly, the lack of long-term monitoring data. However, a palaeoecological study by Gell and Little (2006), which took cores at Balranald Weir and Waugorah Lagoon, estimated that the sedimentation rate was as high as 8.8 mm/yr at weir pools contrasting to around 1 mm/yr (low) to 20 mm/yr (relatively high) in the floodplain swamps.

6.3 Nutrient cycling and trophic dynamics

Although a multitude of concepts, principles and methodologies exist to assist in understanding the biological interactions in floodplain wetlands, the level of knowledge is still relatively rudimentary: very little quantitative information is available on primary productivity, and even less on secondary production. This is particularly true for Yanga National Park: the effects of primary productivity, herbivory, competition and predation on Yanga National Park biota are largely unknown although these processes have an important role in structuring the biological community in aquatic and forest ecosystems. Two current projects will greatly increase the knowledge and understanding of food web structure and trophic dynamics in Yanga National Park:

� Trophic dynamics and ecosystem function of the lower Lachlan and Murrumbidgee (Rivers and Wetlands Unit, OEH)

� Examination of organic matter dynamics and secondary production in floodplain wetlands of the lower Murrumbidgee River (Murray–Darling Freshwater Research Centre).


7 Limits of acceptable change to key ecological components

The concept of limits of acceptable change (LACs), illustrated in Figure 36, is a useful tool, widely used to identify and set limits within which change may be tolerated (Ramsar Convention 1993). It may be applied to long-term or operational objectives. Once these limits are exceeded there will be a need for immediate remedial action.

After Phillips and Muller (2006)

Figure 36: Limits of acceptable change

It is essential to have the knowledge and long-term data and information to assess the range of natural variations in order to set LACs for the components and processes under consideration. This is particularly important for Australian wetlands given that they often have a large range in natural variability (Finlayson and Mitchell 1999; Thoms and Sheldon 2002; Sheldon 2005). However, due to the lack of long-term monitoring programs for this site, the information and data available for setting LACs for most of the ecosystem components, processes, and services presented in the previous sections are less than ideal. Consequently, the proposed LACs are based on a range of information such as specific research, information from similar sites, national and state guidelines and standards, and knowledge of site managers and local residents while considering the site-specific characteristics. Some of the given LACs should be considered as interim.

Another difficulty in setting definite LACs for some ecosystem components and processes is that changes may not be caused by site management. For example, the species composition, distribution, and abundance of migrant birds are known to be highly variable. This may reflect annual differences (changes) in habitat availability elsewhere, variation in climatic conditions, annual variation in the period of peak migration, or annual fluctuations in sizes of bird populations. Thus, exceeding a LAC may send a false alert to wetland and park managers. In this case, a precautionary approach was adopted, especially for threatened species.

Table 25 provides a summary of LACs for the critical components and processes of Yanga National Park. Where appropriate, information required to set definite LACs was identified.

Limits of acceptable

change

Naturalvariability

Long-term variation in a parameter (e.g. salinity,

population)


Tabl

e 25

: Li

mits

of a

ccep

tabl

e ch

ange

for c

ritic

al c

ompo

nent

s an

d pr

oces

ses

of Y

anga

Nat

iona

l Par

k

Inte

rim li

mits

of a

ccep

tabl

e ch

ange

C

ritic

al e

colo

gica

l co

mpo

nent

s an

d pr

oces

ses

Bas

elin

e co

nditi

on a

nd ra

nge

of n

atur

al v

aria

tion

whe

re

know

n S

hort-

term

(1–5

yea

rs)

Long

-term

(10–

100

year

s)

Hyd

rolo

gica

l In

unda

tion

frequ

ency

H

ighl

y va

riabl

e. H

igh

flow

s ar

e ev

ent d

riven

, and

larg

e na

tura

l flo

odin

g oc

curs

in 1

5–20

% o

f yea

rs. T

he im

pact

s of

clim

ate

chan

ge a

re li

kely

to re

duce

the

high

flow

freq

uenc

y. R

iver

re

gula

tion

has

dram

atic

ally

redu

ced

the

low

and

med

ium

flo

ws

sinc

e th

e 19

70s,

and

ther

e ha

s be

en n

o na

tura

l ov

erba

nk fl

ow s

ince

199

6.

Inun

datio

n ar

ea

Hig

hly

varia

ble.

Flo

ods

with

retu

rn p

erio

ds m

ore

than

20

year

s (e

.g. 1

974)

cov

er m

ore

than

90%

of Y

anga

Nat

iona

l Par

k.

Floo

ds w

ith 5

–10

year

s re

turn

per

iods

inun

date

aro

und

60%

of

the

area

. The

cur

rent

inun

datio

n m

appi

ng p

roje

ct w

ill pr

ovid

e m

ore

deta

iled

data

. In

unda

tion

dura

tion

Hig

hly

varia

ble

both

tem

pora

lly a

nd s

patia

lly. N

o qu

antit

ativ

e da

ta. T

he c

urre

nt h

ydro

dyna

mic

mod

ellin

g pr

ojec

t and

hy

drol

ogic

al m

onito

ring

netw

ork

in Y

anga

Nat

iona

l Par

k m

ay

prov

ide

info

rmat

ion

to fi

ll th

e ga

p.

Gro

undw

ater

inpu

ts

Gro

undw

ater

mon

itorin

g da

ta a

re s

patia

lly a

nd te

mpo

rally

in

suffi

cien

t to

draw

any

con

clus

ion

abou

t sur

face

/gro

undw

ater

re

latio

nshi

ps.

Hig

h co

nser

vatio

n ar

eas

(e.g

. Tw

o B

ridge

s S

wam

p, M

erce

des

Sw

amp

and

Pig

gery

La

ke) a

re in

unda

ted

once

eve

ry tw

o ye

ars.

Adv

ice

is n

eede

d to

ad

dres

s th

e im

pact

s of

cl

imat

e ch

ange

.

60%

of t

he a

rea

is

inun

date

d at

leas

t onc

e ev

ery

10 y

ears

.A

dvic

e is

nee

ded

to

addr

ess

the

impa

cts

of

clim

ate

chan

ge.

Env

ironm

ent w

ater

al

loca

tion

Dep

ends

on

wat

er a

vaila

bilit

y as

set

out

in th

e W

ater

Sha

ring

Pla

n fo

r the

Mur

rum

bidg

ee R

egul

ated

Riv

er W

ater

Sou

rce

2003

.3

An a

dequ

ate

shar

e of

w

ater

is a

lloca

ted

to th

e en

viro

nmen

t suc

h th

at

targ

eted

are

as (e

.g. T

wo

Brid

ges

Swam

p, S

haw

s Sw

amp,

Mer

cede

s Sw

amp,

Pig

gery

Lak

e)

are

flood

ed fo

r six

mon

ths

ever

y th

ree

year

s

Targ

eted

are

as g

et th

e en

title

d al

loca

tions

.

3 ww

w.a

ustli

i.edu

.au/

au/le

gis/

nsw

/con

sol_

reg/

wsp

ftmrrw

s200

3648


Inte

rim li

mits

of a

ccep

tabl

e ch

ange

C

ritic

al e

colo

gica

l co

mpo

nent

s an

d pr

oces

ses

Bas

elin

e co

nditi

on a

nd ra

nge

of n

atur

al v

aria

tion

whe

re

know

n S

hort-

term

(1–5

yea

rs)

Long

-term

(10–

100

year

s)

Phys

ical

and

che

mic

al

Sed

imen

tatio

n ra

te

(mm

/yr)

S

patia

lly v

aria

ble.

No

field

mea

sure

men

ts a

vaila

ble.

A

pala

eoec

olog

ical

stu

dy e

stim

ated

that

the

sedi

men

tatio

n ra

te

was

up

to 1

0 m

m/y

r at w

eir p

ools

but

rang

ed fr

om 1

mm

/yr

(ver

y lo

w) t

o 20

mm

/yr (

quite

hig

h) in

the

flood

plai

n sw

amps

. A

curre

nt p

roje

ct to

est

ablis

h th

e be

nchm

ark

and

traje

ctor

y of

se

dim

enta

tion

will

prov

ide

data

to fi

ll th

e ga

p.

2–20

mm

/yr i

n sw

amps

2–

20 m

m/y

r in

swam

ps

Ban

k er

osio

n 8%

of b

ank

leng

th is

uns

tabl

e. H

isto

ric a

eria

l pho

togr

aphy

sh

ows

little

cha

nnel

mov

emen

t.

Adv

ice

need

ed.

Adv

ice

need

ed.

Nut

rient

load

ings

(to

nne/

yr)

No

data

. N

o da

ta to

set

lim

it.

No

data

to s

et li

mit.

Wat

er q

ualit

y (M

urru

mbi

dgee

cha

nnel

at

Red

bank

)

Sal

inity

: goo

d (1

00–3

00 μ

S/cm

). pH

: exc

elle

nt (6

.5–8

.0).

TP: p

oor (

50–8

0μg/

L), o

ccas

iona

lly v

ery

poor

. Tu

rbid

ity: f

air (

16–3

0 N

TU).

DO

: gen

eral

ly p

oor,

but i

nsuf

ficie

nt d

ata.

With

in th

e A

NZE

CC

&

AR

MC

ANZ

(200

0)

guid

elin

es fo

r inl

and

river

s.

With

in th

e A

NZE

CC

&

AR

MC

ANZ

(200

2)

guid

elin

es fo

r inl

and

river

s.

Wat

er q

ualit

y

(floo

dpla

in w

ater

s)

Hig

hly

varia

ble

spat

ially

and

tem

pora

rily.

Lim

ited

data

sug

gest

w

ater

qua

lity

is li

kely

to b

e ve

ry p

oor f

ollo

win

g flo

ods

espe

cial

ly

afte

r a lo

ng d

ry p

erio

d.

Insu

ffici

ent d

ata

to s

et

limit.

Insu

ffici

ent d

ata

to s

et

limit.

Bio

logi

cal

Wat

erbi

rd s

peci

es *

Littl

e is

kno

wn

befo

re w

ater

reso

urce

dev

elop

men

t. A

num

ber

of b

ird s

urve

ys in

the

regi

ons

afte

r the

198

0s b

ut n

o su

rvey

w

as u

nder

take

n in

Yan

ga N

atio

nal P

ark.

Up

to 6

1 sp

ecie

s w

ere

reco

rded

in 1

989

by M

aher

(199

0), w

hich

was

a w

et

year

. 42

spec

ies

wer

e re

cord

ed b

y P

ress

ey e

t al.

(198

4)

durin

g se

vere

dro

ught

(198

2–83

). C

ontin

uous

ly a

eria

l sur

vey

from

198

3 su

gges

ts th

e nu

mbe

r of w

ater

spe

cies

var

ies

cons

ider

ably

with

a ra

nge

of 2

1–40

in th

e Lo

wbi

dgee

regi

on,

and

a ge

nera

l dec

linin

g tre

nd w

as o

bser

ved.

Falli

ng b

elow

21

in tw

o co

nsec

utiv

e ye

ars

base

d on

the

ongo

ing

aeria

l su

rvey

.

Bel

ow 4

2 in

two

cons

ecut

ive

year

s ba

sed

on g

roun

d su

rvey

.

No

net r

educ

tion

in th

e nu

mbe

r of w

ater

bird

sp

ecie

s re

cord

ed.

Wat

erbi

rd a

bund

ance

* Th

ere

is n

o da

ta b

efor

e th

e 19

80s.

The

aer

ial s

urve

y su

gges

ts th

at th

e ab

unda

nce

is h

ighl

y va

riabl

e ra

ngin

g fro

m

21,7

00 to

139

,000

, and

sho

ws

a st

rong

dec

linin

g tre

nd in

the

Low

bidg

ee re

gion

.

Less

than

the

min

imum

(a

bout

22,

000)

cou

nt fo

r tw

o co

nsec

utiv

e ye

ars

base

d on

aer

ial s

urve

y.

No

net r

educ

tion

in

abun

danc

e.


Inte

rim li

mits

of a

ccep

tabl

e ch

ange

C

ritic

al e

colo

gica

l co

mpo

nent

s an

d pr

oces

ses

Bas

elin

e co

nditi

on a

nd ra

nge

of n

atur

al v

aria

tion

whe

re

know

n S

hort-

term

(1–5

yea

rs)

Long

-term

(10–

100

year

s)

Nat

ive

fish

(Mur

rum

bidg

ee

chan

nel)

S

ome

stud

ies

sam

pled

the

low

er M

urru

mbi

dgee

cha

nnel

. N

ine

spec

ies

wer

e re

cord

ed in

200

0–01

. D

ata

insu

ffici

enta

t thi

s tim

e.N

o ne

t los

s in

nat

ive

fish

spec

ies.

N

ativ

e fis

h

(floo

dpla

in w

ater

bod

ies)

In

form

atio

n be

fore

the

1990

s is

sca

rce

and

unsy

stem

atic

. Fiv

e sp

ecie

s w

ere

sam

pled

in 1

999

and

eigh

t wer

e re

cord

ed in

20

08.

Nat

ive

fish

abun

danc

e w

as lo

w c

ompa

red

to in

trodu

ced

spec

ies

in a

ll ty

pes

of h

abita

ts.

Dat

a in

suffi

cien

tat t

his

time.

LA

Cs

for n

ativ

e fis

h sp

ecie

s ar

e cl

osel

y lin

ked

with

the

Mur

rum

bidg

ee R

iver

ch

anne

l.

No

net l

oss

in n

ativ

e fis

h sp

ecie

s.

Num

ber o

f inv

erte

brat

es

spec

ies

and

abun

danc

e N

o in

form

atio

n an

d da

ta. L

ikel

y re

duce

d in

div

ersi

ty a

nd

abun

danc

e be

caus

e of

hab

itat l

oss.

D

ata

insu

ffici

enta

t thi

s tim

e.N

o ne

t los

s of

spe

cies

.

Abu

ndan

ce a

nd

dist

ribut

ion

of s

outh

ern

bell

frog

The

sout

hern

bel

l fro

g w

as a

bund

ant a

nd w

idel

y di

strib

uted

(r

iver

red

gum

fore

sts

and

blac

k bo

x/lig

num

sw

amps

) th

roug

hout

Low

bidg

ee fl

oodp

lain

unt

il th

e ea

rly 2

000s

. It i

s un

clea

r whe

n th

e po

pula

tion

bega

n to

dec

line.

Cur

rent

ly,

ther

e ar

e lo

w n

umbe

rs o

f sou

ther

n be

ll fro

gs in

key

site

s (M

erce

des,

Tw

o B

ridge

s).

No

loss

of p

opul

atio

n in

ke

y si

tes.

A

dvic

e ne

eded

.

Oth

er th

reat

ened

spe

cies

Th

ere

are

22 e

ndan

gere

d an

d vu

lner

able

spe

cies

reco

rded

. N

o ch

ange

s in

div

ersi

ty.

No

net l

oss

of s

peci

es.

Hab

itats

La

rge

flood

plai

n la

kes

Yan

ga L

ake

and

Tala

Lak

e ha

ve b

een

dry

sinc

e 20

01. N

o hi

stor

ical

dat

a do

cum

ents

the

varia

tions

in o

pen

wat

er a

rea

of

the

lake

s.

Dry

to fu

ll In

unda

ted

at le

ast o

nce

in

10 y

ears

.

Sha

llow

mar

shes

A

roun

d 15

00 h

a, in

clud

es P

igge

ry L

ake,

Tw

in B

ridge

Sw

amp,

M

erce

des

Sw

amp.

N

o lo

ss o

f wet

land

s.

No

net l

oss

in a

rea

of

wet

land

s.

The

area

of r

iver

red

gum

s re

mai

ns a

t 22,

000

ha fo

r the

last

5–

6 de

cade

s ba

sed

on a

eria

l pho

togr

aphy

. N

o lo

ss o

f riv

er re

d gu

m

fore

st/w

oodl

and.

A

dvic

e ne

eded

. R

iver

red

gum

fo

rest

/woo

dlan

d Th

e co

nditi

on o

f riv

er re

d gu

m fo

rest

/woo

dlan

d ha

s be

en

decl

inin

g si

nce

the

1970

s. C

urre

ntly

, the

re a

re o

nly

abou

t 20

00 h

a of

rive

r red

gum

in g

ood

cond

ition

. The

rem

aini

ng

fore

sts

are

in p

oor t

o ve

ry p

oor c

ondi

tion.

Aro

und

1350

ha

are

dead

tree

sta

nds.

Con

ditio

n of

ripa

rian

vege

tatio

n at

key

site

s (T

wo

Brid

ges,

Bre

er

Sw

amp,

Tal

pee

Cre

ek,

Pig

gery

Lak

e) is

m

aint

aine

d.

Adv

ice

need

ed.


Inte

rim li

mits

of a

ccep

tabl

e ch

ange

C

ritic

al e

colo

gica

l co

mpo

nent

s an

d pr

oces

ses

Bas

elin

e co

nditi

on a

nd ra

nge

of n

atur

al v

aria

tion

whe

re

know

n S

hort-

term

(1–5

yea

rs)

Long

-term

(10–

100

year

s)

Ther

e ar

e ab

out 1

2,00

0 ha

of b

lack

box

in Y

anga

Nat

iona

l P

ark.

The

ext

ent o

f bla

ck b

ox w

oodl

and

has

rem

aine

d co

nsta

nt fo

r the

last

50

year

s, b

ased

on

aeria

l pho

togr

aphy

.

No

loss

of b

lack

box

w

oodl

and.

A

dvic

e ne

eded

. B

lack

box

woo

dlan

d

The

cond

ition

of b

lack

box

woo

dlan

d ha

s be

en d

eclin

ing

sinc

e th

e 19

70s.

A

dvic

e ne

eded

A

dvic

e ne

eded

Ther

e ar

e ab

out 1

300

ha o

f lig

num

sw

amps

in Y

anga

Nat

iona

l P

ark.

In th

e N

imm

ie–C

aira

cou

ntry

, lar

ge a

reas

of l

ignu

m

swam

p w

ere

clea

red

or a

re b

eing

dis

plac

ed b

y cu

mbu

ngi a

s a

resu

lt of

pro

long

ed in

unda

tion.

No

loss

in a

rea

of li

gnum

sh

rubl

ands

. N

o lo

ss in

are

a of

lign

um

shru

blan

ds.

Lign

um s

wam

p

Poo

r to

very

poo

r con

ditio

n.

Adv

ice

need

ed.

Adv

ice

need

ed.

Oth

er te

rrest

rial w

oodl

and

and

bush

land

M

ore

than

30,

000

ha.

No

net l

oss.

N

o ne

t los

s.

* A

s th

e ae

rial b

ird s

urve

y is

the

only

ava

ilabl

e lo

ng-te

rm m

onito

ring

data

, LA

Cs

for s

peci

es a

nd a

bund

ance

of w

ater

bird

s ar

e ba

sed

on a

eria

l sur

vey.

H

owev

er, i

f lon

g-te

rm g

roun

d-ba

sed

bird

mon

itorin

g pr

ogra

m is

to b

e im

plem

ente

d, L

AC

s sh

ould

be

base

d on

gro

und-

base

d da

ta.


8 Actual and likely threats to the ecological character of Yanga National Park

The aim of this section is to identify the threats to ecological character, i.e. those that cause adverse changes in the ecological character of Yanga National Park. The threats are summarised in Table 26 using the threat classification hierarchy developed by the International Union for the Conservation of Nature and the Conservation Measures Partnership (IUCN-CMP),4 and detailed in the following sections. Because of the geographic settings and agricultural history, the threats identified for the Lowbidgee floodplain are also applicable to Yanga National Park.

Based on Table 26, a conceptual model (Figure 37) was developed specifically for risk management for Yanga National Park. Because of the land tenure change, and thus the development of a management strategy, many threats identified in Table 26 (e.g. agriculture) were not included in Figure 37. Furthermore, climate change and a mitigation and adaptation strategy should be addressed at global, national and regional scales; therefore these are not included in the model. The model illustrates the ecological linkages among the major threats (distinguished as external pressures and system-wide stressors), effects and ecological characters. The cause and effect relationships explain the important consequences of system-wide stressors on the major ecological attributes of Yanga National Park. These stressors, which include flood reduction, loss and shift of natural discharge variability, floodplain loss and fragmentation, are further discussed below.

8.1 Alteration to the natural flow regimes

Alteration to natural flow regimes refers to reducing or increasing flows, altering seasonality of flows, changing the frequency, duration, magnitude, timing, predictability and variability of flows, altering surface and subsurface water levels, and changing the rate of rise or fall of water levels (NRC 1992). In the lower Murrumbidgee downstream major irrigation areas, the alteration is realised principally as reduction in river flows (Page et al. 2005; Wen 2009). Alteration to natural flow regime and water resource development is directly related. In Lowbidgee, like elsewhere in the Murray–Darling Basin, natural flow regimes have been interrupted through three human processes due to water resource development pressure: river regulation (dam and weir), water diversion (includes groundwater pumping), and alteration of flows within floodplains with levees and structures (such as bank enforcement).

Alteration to the natural flow regimes of rivers and streams and their floodplains and wetlands is listed as a key threatening process on Schedule 3 of the TSC Act. A direct and most significant consequence of alteration to the natural flow regimes in the Lowbidgee floodplain is the dramatic reduction in frequency and duration of overbank flows, which in turn is recognised as a major factor contributing to loss of biological diversity and ecological function (Briggs et al. 1997; Sherman et al. 1998; Kingsford and Thomas 2004; Gilligan 2005; Wen et al. 2009). Impacts associated with reduced flooding relevant to Yanga National Park include: � loss of lateral connectivity with the Murrumbidgee � loss of persistent soil moisture levels � loss of ecological function � increased fire risk � ultimately, degradation of floodplain habitat.

4 http://iucn.org/about/work/programmes/species/red_list/resources/technical_documents/new_classification_schemes/


8.2 Habitat loss and fragmentation

Together with the reduction of flooding, floodplain development, which includes the construction and enforcement of banks, levees and regulators, clearing of lignum, and creation of water storages, accelerated the loss and fragmentation of floodplain habitats in the Lowbidgee floodplain. While the development of floodplains for agricultural production in Yanga National Park ceased in 2005, existing infrastructure in the Nimmie–Caira system has management implications for Yanga National Park. For example, the blockages along Fiddlers Creek prevent water entering Yanga Nature Reserve.

Using historical floodplain maps and satellite imagery, Kingsford and Thomas (2001) investigated floodplain loss in Lowbidgee from the turn of the 20th century. They found that 127,688 ha (58%) of wetlands have been lost to developed land in the lower Murrumbidgee region. In Yanga National Park, the loss was 37,253 ha (41%).

In the developed area of the lower Murrumbidgee floodplain, particularly in the Nimmie–Caria FCID, a water delivery and retaining network, which has about 2,100 km of banks and 394 km of constructed channels (Kingsford and Thomas 2001), has been developed since the completion of Redbank and Maude weirs. The main purpose of the network is to deliver water efficiently and quickly. However, besides distributing floodwater, the natural floodway network, including streams and flood runners, also provides hydrological continuity for nutrients and aquatic animals such as fish, amphibians and waterbirds. Consequently, the development and operation of the modified network has increased habitat isolation through preventing water reaching some floodplain areas and prolonging inundation of targeted areas. For example, the Southern Caira channel was built to bypass the floodway and allow more efficient transmission to irrigated areas downstream and key habitat areas (DLWC 1997). In the meantime, the channel bank also isolated the southern part of the floodplain from flood flows because it was constructed above the estimated 1956 flood level (one in 100 years) at the site and did not allow passage of floodwater, so the levee needed to be breached during floods (DWR 1994).

The diversion of water from Redbank and Maude weirs is generally beneficial for the flora and fauna on the Lowbidgee floodplain as it compensates the reduction of overbank flow due to upstream water extraction. For example, bank construction and water storages have enhanced waterbird breeding, particularly ibis, in the Telephone and Eulimbah swamps (Maher 1990). However, water storages, which have artificially enhanced wet periods (more than two years), may be of lower quality as waterbird (Maher 1990) and fish habitat. Furthermore, the prolonged inundation favours the spread of cumbungi (Typha domingensis) (Pressey et al. 1984; Maher 1990; Eddy 1992; DLWC 1997; Kingsford and Thomas 2001). In more permanent water habitats, cumbungi tends to dominate over lignum and becomes a major cause of decline in lignum areas in the Lowbidgee (DLWC 2000). In April 1997 the Nimmie–Caira floodway system was infested with approximately 3530 hectares of cumbungi, representing some 15% of the total floodway vegetation (DLWC 1997).


Tabl

e 26

: S

umm

ary

of a

ctua

l and

like

ly th

reat

s to

the

ecol

ogic

al c

hara

cter

of t

he L

owbi

dgee

floo

dpla

in

Thre

at th

eme

(thre

at c

lass

: lev

el 1

) Th

reat

act

ivity

(th

reat

cla

ss: l

evel

2)

Thre

at a

gent

(th

reat

cla

ss: l

evel

3)

Tim

efra

me

Like

lihoo

d

Ups

tream

sur

face

wat

er e

xtra

ctio

n

Imm

edia

te–m

ediu

m

Hig

h S

truct

ures

, inc

ludi

ng fl

oodg

ates

, cu

lver

ts, l

evee

s, ro

ad c

ross

ings

Im

med

iate

–med

ium

M

ediu

m

Dam

s an

d w

ater

div

ersi

on

Irrig

atio

n sa

linity

M

ediu

m

Low

Lo

ss o

f ope

n w

ater

Im

med

iate

–med

ium

H

igh

Hab

itat c

hang

e M

ediu

m–l

ong

Hig

h H

abita

t shi

fting

and

alte

ratio

n S

heet

ero

sion

Im

med

iate

–med

ium

Lo

w

Nat

ural

fire

Im

med

iate

–med

ium

M

ediu

m

Nat

ural

sys

tem

m

odifi

catio

ns

Fire

and

fire

sup

pres

sion

A

rson

Im

med

iate

–med

ium

Lo

w

Agr

icul

ture

C

lear

ing

Imm

edia

te–m

ediu

m

Low

Ann

ual n

on-ti

mbe

r cro

ps

Irrig

ated

pas

ture

s an

d cr

oppi

ng

Imm

edia

te–m

ediu

m

Med

ium

Li

vest

ock/

nativ

e an

imal

gra

zing

G

razi

ng

Imm

edia

te–m

ediu

m

Med

ium

A

gric

ultu

re

Fish

ing

and

harv

estin

g aq

uatic

re

sour

ces

Rec

reat

ion

Imm

edia

te–m

ediu

m

Low

Illeg

al ta

ke

Imm

edia

te–m

ediu

m

Low

B

iolo

gica

l res

ourc

e us

e H

untin

g of

wat

erbi

rds

Rec

reat

ion

Imm

edia

te–m

ediu

m

Low

D

roug

ht

Dro

ught

M

ediu

m–l

ong

Hig

hS

torm

s an

d flo

odin

g Fl

ood

Imm

edia

teLo

wS

trong

win

d W

ind

eros

ion

Imm

edia

teM

ediu

mC

limat

e ch

ange

and

se

vere

wea

ther

Tem

pera

ture

ext

rem

es

Wat

er te

mpe

ratu

re c

hang

e M

ediu

m–l

ong

Med

ium

D

eter

iora

tion

of v

eget

atio

n he

alth

M

ediu

m–l

ong

Hig

h E

cosy

stem

/com

mun

ity

stre

sses

E

cosy

stem

deg

rada

tion

Enc

roac

hmen

t of c

heno

pod

into

se

dge

M

ediu

m–l

ong

Hig

h


Thre

at th

eme

(thre

at c

lass

: lev

el 1

) Th

reat

act

ivity

(th

reat

cla

ss: l

evel

2)

Thre

at a

gent

(th

reat

cla

ss: l

evel

3)

Tim

efra

me

Like

lihoo

d

Inap

prop

riate

con

serv

atio

n m

easu

res

Allo

catio

n of

env

ironm

enta

l wat

er

Imm

edia

te–m

ediu

m

Med

ium

Hun

ting

Imm

edia

te–m

ediu

m

Low

Hum

an in

trusi

ons

and

dist

urba

nce

Rec

reat

iona

l act

iviti

es

Eco

tour

ism

M

ediu

m

Low

Eur

opea

n ca

rp

Imm

edia

te–m

ediu

m

Hig

h Fe

ral p

ig

Imm

edia

te–m

ediu

m

Med

ium

R

ed d

eer

Imm

edia

te–m

ediu

m

Low

Fe

ral c

at

Imm

edia

te–m

ediu

m

Med

ium

R

abbi

t Im

med

iate

–med

ium

Lo

w

Eur

opea

n re

d fo

x Im

med

iate

–med

ium

M

ediu

m

Lipp

iaIm

med

iate

–med

ium

M

ediu

m

Inva

sive

exo

tic s

peci

es

Oth

er p

lant

s Im

med

iate

–med

ium

Lo

w

Inva

sive

and

oth

er

prob

lem

atic

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cies

and

ge

nes

Oth

er p

robl

emat

ic s

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nd

gene

s To

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alga

e

Imm

edia

te–m

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m

Hig

h

Her

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Imm

edia

te

Low

Nut

rient

s Im

med

iate

M

ediu

mA

gric

ultu

ral e

fflue

nt

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imen

ts

Imm

edia

te–m

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m

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Toxi

ns

Imm

edia

te

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d su

lfate

soi

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ium

Low

Nut

rient

s Im

med

iate

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ium

Lo

w

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lutio

n

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ourc

es

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ticid

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edia

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Low

Thre

ats

hier

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m IU

CN

-CM

P, h

ttp://

iucn

.org

/abo

ut/w

ork/

prog

ram

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/spe

cies/

red_

list/r

esou

rces

/tech

nica

l_do

cum

ents

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Figu

re 3

7:

Con

cept

ual e

colo

gica

l mod

el o

f ris

ks in

Yan

ga N

atio

nal P

ark


The development plan for the lower Murrumbidgee floodplain (DWR 1989, 1994) emphasised the conservation needs of identified special habitat areas or rookeries (e.g. Avalon Swamp, Nap Nap Swamp, Telephone Banks Rookery), while development was permitted elsewhere on the floodplain. Consequently, a constricted distribution of floodways (through enforcement of natural levees) and isolated rookeries (targeted artificial watering) would be maintained, reflecting the narrow definition of ecosystem function applied.

8.3 Introduced and problematic species

The Atlas of NSW Wildlife contains records of 58 introduced plant species in Yanga National Park, of which the majority are small ground plants, and some of these are widespread and abundant, such as Paterson’s curse (Echium plantagineum),horehound (Marrubium vulgare), onion weed (Romulea rosea var. australis) and spear thistle (Cirsium vulgare (Savi) Ten.). The wide spread of introduced small ground plants (some are valued as stock feed, e.g. medics – Medicago spp.) reflects the agricultural history of the site. The prolonged dry period in water-plant dominated areas (i.e. shallow temporary swamps) and lake beds increases the risk of exotic plant invasion.

As mentioned in section 8.2, cumbungi infestation of lignum swamps and permanent water ways is common at Lowbidgee, especially at Nimmie–Caria FCID due to the artificially enhanced inundation.

A number of surveys found that introduced fish species, in particular European carp, goldfish (Carassius auratus) and eastern gambusia, dominate waterways (including the Murrumbidgee channel and wetlands) (Bales 1999; Baumgartner 2004; Wassens 2008a; Spencer and Allman 2008; J Kelleway 2009, pers. comm.). Introduced fish species pose a threat to native fish species as predators, competitors, disease carriers and through modification of habitat (Fisheries Scientific Committee 2001) and are thought to be a significant contributor to reductions in native fish species abundance in the Murrumbidgee catchment (Gilligan 2005). Predation by European carp may also contribute to the decline in the southern bell frog population in Lowbidgee (Wassens 2008a). The introduction of fish to fresh waters within a river catchment outside their natural range has been listed as a key threatening process in Schedule 6 of the Fisheries Management Act (Fisheries Scientific Committee 2008).

Other introduced animals of concern include feral pigs, cats and European red foxes. These animals predate on small native animals (e.g. lizards, frogs and ground-nesting birds). They are all listed as key threatening processes in NSW by the NSW Scientific Committee because of their impacts on native animals (DECC 2008).

8.4 Climate change

Changes in global climate – warming temperatures, rising sea level and variations in rainfall and storm patterns – could have tremendous human and ecological impacts (Figure 38).

The resilience of many ecosystems is likely to be exceeded this century by an unprecedented combination of climate change, associated disturbances (e.g. flooding, drought, wildfire, insects, ocean acidification) and other global change drivers (e.g. land-use change, pollution, overexploitation of resources) (IPCC 2007).


8.4.1 Higher temperatures

Increasing temperatures globally are likely to result in a warming of water in lakes and rivers. Increases in water temperature will cause a shift in the thermal suitability of aquatic habitats for resident species. The metabolic rates of organisms and the overall productivity of ecosystems are directly regulated by temperature. Projected increases in temperature are expected to disrupt present patterns of plant and animal distribution in aquatic ecosystems.

8.4.2 Changes to rainfall patterns and intensity

Some climate change models predict possible increases in the intensity and rainfall on fewer rainy days (Kattenberg et al. 1995), as has already been observed in precipitation data in Australia. The implications for streams and rivers and the water bodies are significant. A direct result of these is an increase in flood frequency and changes in flood magnitude. Because the transport and storage of nutrients and pollutants depend on flow, an increase in floods would probably result in more silt and pollutants entering streams and rivers and their receiving water bodies. The corresponding degradation in water quality could lead to a loss of sensitive stream species (Meyer et al. 1999). Further, floods scour the stream bed and displace stored organic carbon (food resources for many species), bottom-dwelling organisms and larval fish.

8.5 Other issues

Prior to 2005, numerous land management practices occurred in Yanga National Park, including grazing, clearing, logging and burning. Although all these practices have been stopped since gazettal as a national park in 2007, some of them have long lasting impacts on the ecological character of the site. Furthermore, these land management activities are practised in the surrounding areas, and have direct or indirect effects on Yanga National Park.

CO2

Air temperature

Water temperature

Sea level

Runoff regime-Magnitude-Frequency-Timing-Duration

Rainfall pattern and intensity

Ecosystem responses-Biota metabolism-Species distribution-Habitat availability and quality-Habitat connectivity-Nutrient availability, productivity-Lake mixing-Water chemistry

Human responses

CO2CO2

Air temperatureAir temperature

Water temperatureWater temperature

Sea levelSea level



Rainfall pattern and intensityRainfall pattern and intensity

Ecosystem responses-Biota metabolism-Species distribution-Habitat availability and quality-Habitat connectivity-Nutrient availability, productivity-Lake mixing-Water chemistry

Human responses

Solid arrows indicate very likely impacts and dashed arrows indicate likely impacts (IPCC 2007).

Figure 38: Linkages between climate change and ecosystem responses


Grazing by livestock and native or other introduced animals has been observed to have a significant impact on the condition of vegetation communities in the Lowbidgee (Beadle 1948; Cunningham et al. 1981; Pressey et al. 1984; Scott 1992; Benson et al. 2006). Grazing has direct impacts on vegetation community structure by altering the relative abundance of floodplain plants. For example, more tolerant species, such as water couch (Paspalum distichum), are likely to become increasingly abundant as a result of intensive grazing, which may prevent the regeneration of river red gums (Jacobs 1955). Other impacts associated with grazing include puddling, trampling, reducing plant biomass and altered nutrient cycling.

Clearing, in particular the clearing of lignum communities, has occurred in the lower Murrumbidgee for decades, and 60% of the estimated 40,000 ha of lignum in Lowbidgee was cleared by 1988 (Cross et al. 1991, cited in Kingsford and Thomas 2001).

The river red gum forests of Yanga National Park have been logged to varying degrees over the past 150 years, and some areas have been extensively logged until very recently (Maher 1999). Large-scale logging could change the landscape from scattered, mature tree stands with patches of younger trees to dense even-aged regrowth; consequently, these areas would lose value as fauna habitats. For instance, apart from the general faunal values, hollows in river red gums are particularly important for breeding and sheltering of a range of species (e.g. grey teal, bats).

Small-scale burning has occurred in Yanga National Park to control the growth of common reed. Burning would have an impact on floodplain flora and fauna; however, the impact is likely to be localised and temporary. Burning in patches may even enhance the ecological values by diversifying the vegetation structure and breaking down soil organic matter, consequently accelerating nutrient cycling.


9 Knowledge gaps There are substantial knowledge gaps that limit the optimisation of Yanga National Park management. These knowledge gaps are an ongoing problem for describing ecological character, setting LACs, identifying potential and actual threats, and initiating management actions to address the threats. Table 27 summarises the fundamental knowledge gaps and recommended actions to address the gaps. Many of these relate to the monitoring program recommended in section 10.

A number of scientific research projects, mainly under RERP, are currently underway in Lowbidgee (many focus on Yanga National Park) to investigate the relationships between floodplain ecology and hydrology. Three major components of the program are particularly valuable for filling the knowledge gaps identified in Table 27:

� Physical settings � digital elevation models based LiDAR Survey � bathymetric for significant wetlands and lakes � soil surveys.

� Hydrological drivers � hydrodynamic modelling � hydrological modelling � Yanga flow gauging network � groundwater monitoring network � inundation mapping.

� Ecological responses � trophic dynamics based on isotopic analysis of keystone species and trophic

levels� maps of current and historical vegetation extent and condition � tree health survey � seedbank and eggbank investigation � Lowbidgee frog monitoring � waterbird and fish surveys � palaeoecological studies in key sites � land-use and organic matter study.

The majority of these projects are currently at the phase of data collection; therefore findings and conclusions have yet to be incorporated in the description of ecological character. Nevertheless, the current vision of the description has integrated the most up-to-date data and information collected by the program, such as frog monitoring and historic vegetation mapping. It is strongly recommended that an updated vision which integrates the findings from these studies should be developed before the end of the RERP in 2011.


Table 27: Key knowledge gaps and recommended monitoring and actions

Category Component and process

Identified knowledge gaps Recommendations Priority

Heritage Aboriginal and European heritage

Most of the Aboriginal sites have been destroyed.

Liaising with Aboriginal representatives to identify heritage items and areas of spiritual significance

Mediumto high

Surface/groundwater interaction

No quantified data to estimate the surface/ groundwater interaction

Monitoring groundwater levels

Low to medium

Floodwater including EWA distribution patterns

Preferential flow paths Distribution of temporary wetlands

Digital elevation model and terrain model

High

Hydrological

Inundation patterns for key wetlands

Distribution, extent, duration and timing of inundation of key wetlands

Installation of gauges in key wetlands

High

Temporary wetlands Macrophytes species and abundance

River red gum forest /woodland

Age class and current conditionResponse to inundation

Lignum swamp Current condition Response to inundation

Habitatabundance and quality

Black box woodland Current condition Response to inundation

Vegetationsurvey(prior to, during and post inundation) in key wetlands

Permanent transects in representative vegetationcommunities

High

Waterbirds Understanding the causes of declining trends in diversity and abundance

Long-term monitoring High

Macroinvertebrates No comprehensive macroinvertebrate surveys

Annual survey of macroinvertebrates in key sites (including river channels)

Medium

Threatened fauna No information about the population trend of threatened species (other than the southern bell frog).

Targeted survey High

Other fauna Lack of fauna surveys Fauna survey, especially for bats, small mammals and reptiles

Low to medium

Fish Fish usage of floodplain Fish survey across the floodplain

Medium

Fauna

Introduced species Impacts of feral predators on waterbirds and small native mammal populations

Scats and remains analysis

Low to medium


Category Component and process

Identified knowledge gaps Recommendations Priority

Sedimentation rate There is little or inconclusive information about the relationship between the rate of sedimentation rate and hydrological regimes.

Targeted study Low to medium

Physical and chemical

Water quality No systematic water quality data (DO, pH, nutrients, salinity, turbidity)

Monthly water quality at gauging sites when water present

Mediumto high

EWA Distribution and volume Installation of flow gauges

Mediumto high

Human disturbances

Park visitors Medium

10 Recommended monitoring program

10.1 Monitoring objectives

The objectives of the monitoring program are as follows: � to gather information to provide or improve the understanding and description of the

ecological character of Yanga National Park � to obtain data and information about the natural variation range of critical ecosystem

drivers, components and processes for setting LACs � to detect change, or likely change, in the ecological character of the site as set out in

sections 2–8 of this report � to assess the efficiency of management actions and conservation efforts.

10.2 Recommended monitoring framework

The recommended monitoring framework for Yanga National Park is presented in Table 28. These recommendations are based on the knowledge gaps identified in section 8 and particularly those required for setting LACs as highlighted in section 7.


Tabl

e 28

: R

ecom

men

ded

mon

itorin

g pr

ogra

m fo

r Yan

ga N

atio

nal P

ark

Ecol

ogic

alch

arac

ter

Mon

itorin

gco

mpo

nent

O

bjec

tives

In

dica

tor/M

easu

re

Freq

uenc

y Pr

iorit

y

Cul

tura

lAb

orig

inal

site

s Es

tabl

ish b

asel

ine

cond

itions

. Lo

catio

n an

d co

nser

vatio

n st

atus

of A

borig

inal

sit

es.

Surv

ey o

nce

Hig

h

Rive

r flo

ws

Impa

ct a

sses

smen

t. Es

tabl

ish re

quire

men

ts o

f wet

land

co

mm

unitie

s w

ithin

the

Low

bidg

ee

and

how

this

rela

tes

to d

ischa

rge

at

Mau

de a

nd R

edba

nk w

eirs

. C

hang

e de

tect

ion.

Wat

er le

vel a

nd d

ischa

rge

at M

aude

Wei

r.

Wat

er le

vel a

nd d

ischa

rge

at R

edba

nk W

eir.

Disc

harg

e at

Yan

ga re

gula

tor.

Con

tinuo

usly

Con

tinuo

usly

Con

tinuo

usly

per e

vent

Hig

hH

igh

Hig

h

Gro

undw

ater

Es

tabl

ish b

asel

ine

cond

itions

. Se

t lim

its o

f cha

nge

Gro

undw

ater

leve

l.

Con

tinuo

usly

Med

ium

H

ydro

logi

cal

Flow

pat

hs a

nd

dist

ribut

ion

Esta

blish

requ

irem

ents

of w

etla

nd

com

mun

ities

Im

pact

ass

essm

ent.

Cha

nge

dete

ctio

n.

Wat

er le

vel a

t key

site

s.

Flow

at k

ey s

ites.

C

ontin

uous

ly pe

r eve

nt

Hig

h

Hab

itat

abun

danc

e

and

qual

ity

Vege

tatio

n ty

pes,

flo

ral s

truct

ure,

di

strib

utio

n an

d ex

tent

Esta

blish

the

wat

er re

quire

men

ts o

f ke

y co

mm

unitie

s.

Set L

ACs.

D

etec

t cha

nges

. As

sess

impa

ct.

Map

ping

ext

ent o

f mai

n ve

geta

tion

type

s (p

riorit

ies

give

n to

rive

r red

gum

com

mun

ities

and

sedg

e sw

amps

). C

ondi

tion

of ri

ver r

ed g

um tr

ee s

tand

s.

The

age

stru

ctur

e of

rive

r red

gum

fore

st.

Ever

y 3

year

s

Ever

y 3

year

s O

nce

Hig

h

Hig

hLo

w

Biol

ogica

l:fa

una

Wat

erbi

rds

Esta

blish

the

habi

tat r

equi

rem

ents

of

wat

erbi

rds.

Se

t LAC

s.

Asse

ss im

pact

s.

Esta

blish

the

depe

nden

ce o

f w

ater

bird

s on

hab

itat i

n th

e Lo

wbi

dgee

.

Pres

ence

or a

bsen

ce o

f wat

erbi

rd s

pecie

s Pr

esen

ce o

r abs

ence

of t

arge

t spe

cies

Num

bers

of b

reed

ing

pairs

N

umbe

r of n

ests

N

umbe

r of f

ledg

es

Annu

ally

in

sprin

g (w

eekly

for

targ

eted

spec

ies

durin

g EW

A)

Hig

h


Ecol

ogic

alch

arac

ter

Mon

itorin

gco

mpo

nent

O

bjec

tives

In

dica

tor/M

easu

re

Freq

uenc

y Pr

iorit

y

Nat

ive fi

sh

Esta

blish

the

habi

tat r

equi

rem

ents

of

nat

ive fi

sh.

Iden

tify

refu

gia

for f

ish in

the

Mur

rum

bidg

ee s

yste

m fr

om w

hich

th

ey c

an m

igra

te.

Set L

ACs.

D

etec

t cha

nges

. As

sess

impa

cts.

Pres

ence

or a

bsen

ce a

nd a

bund

ance

of

nativ

e sp

ecie

s.

Pres

ence

or a

bsen

ce a

nd a

bund

ance

of

intro

duce

d sp

ecie

s.

Annu

ally

in

sprin

g H

igh

Mac

roin

verte

brat

es

Esta

blish

bas

elin

e co

nditio

n.

Set L

ACs.

D

etec

t cha

nges

. As

sess

impa

cts.

Taxa

pre

senc

e or

abs

ence

. Ab

unda

nce.

O

bser

ved

or e

xpec

ted

scor

e (if

ava

ilabl

e).

Qua

rterly

M

ediu

m

Sout

hern

bel

l fro

g Se

t LAC

s.

Asse

ss im

pact

s.

Det

ect c

hang

es.

Popu

latio

n siz

e.

Hab

itat c

ondi

tions

. N

umbe

r of t

adpo

les

and

met

amor

phos

es.

Annu

ally

(wee

kly d

urin

g EW

A)

Hig

h

Thre

aten

ed s

pecie

s Es

tabl

ish b

asel

ine.

As

sess

impa

cts.

N

umbe

r of s

pecie

s.

Popu

latio

n siz

e.

Hab

itat c

ondi

tions

.

Ever

y 3

year

s H

igh

Oth

er fa

una

Esta

blish

bas

elin

e.

Set L

ACs.

N

umbe

r of s

pecie

s.

Popu

latio

n siz

e.

Ever

y 3

year

s Lo

w

Biol

ogica

l:ph

ytop

lank

ton

Phyt

opla

nkto

n Se

t LAC

s.

Esta

blish

bas

elin

e co

nditio

ns.

Blue

-gre

en a

lgae

spe

cies

and

biov

olum

e.

Phyt

opla

nkto

n sp

ecie

s.

Mon

thly

Low

Lo

w

Wat

er Q

uality

Phys

ico-c

hem

ical

para

met

ers

Se

t LAC

s.

Esta

blish

bas

elin

e co

nditio

ns.

Turb

idity

. N

utrie

nts

(nitr

ogen

and

pho

spho

rus)

. Sa

linity

.D

O.

pH.

Mon

thly

M

ediu

m

Sedi

men

tatio

n ra

te

Esta

blish

bas

elin

e co

nditio

ns.

Set L

ACs.

Se

dim

enta

tion

rate

tren

d.

Onc

e M

ediu

m

Sedi

men

tSe

dim

ent q

uality

Es

tabl

ish b

asel

ine

cond

itions

. Se

t LAC

s.

Gra

in s

ize

Tota

l org

anic

carb

on a

nd n

utrie

nt le

vels

Onc

e M

ediu

m


Ecol

ogic

alch

arac

ter

Mon

itorin

gco

mpo

nent

O

bjec

tives

In

dica

tor/M

easu

re

Freq

uenc

y Pr

iorit

y

Rec

reat

ion

activ

ity

Asse

ss im

pact

s.

No

of to

urist

s.

No

of v

ehicl

es.

No

of c

amps

ites

or te

nts.

Ong

oing

M

ediu

m

Intro

duce

d w

eed

inva

sion

Det

ect c

hang

e.

Asse

ss im

pact

s.

Exte

nt.

Rat

e of

spr

ead

over

with

in h

abita

t. Bi

annu

ally

Lo

w

Nut

rient

load

ing

Det

ect c

hang

e.

Asse

ss im

pact

s.

Tota

l pho

spho

rus.

To

tal n

itrog

en.

Der

ive fr

om

hydr

olog

ical

and

wat

er

qual

ity

Low

Envir

onm

enta

l wat

er

allo

catio

nAs

sess

impa

ct.

Fulfil

l lega

l obl

igat

ions

. W

ater

vol

ume.

D

elive

ry ti

me.

In

unda

tion

exte

nt, d

epth

and

dur

atio

n.

Even

t bas

ed

Hig

h

Hum

an

inte

rven

tion

Envir

onm

enta

l wat

er

allo

catio

nAs

sess

impa

ct.

Fulfil

l lega

l obl

igat

ions

. W

ater

vol

ume.

D

elive

ry ti

me.

In

unda

tion

exte

nt, d

epth

and

dur

atio

n.

Even

t bas

ed

Hig

h


11 Communication, education and public awareness messages

The only way to maintain the ecological character of Yanga National Park and other parts of the Lowbidgee floodplain (by reducing the loss of biodiversity and protecting habitats) is to gain the collaboration and cooperation of individuals, organisations and community groups to act on threats to the sites. Communication, education and public awareness (CEPA) plays an important role in developing and forging this collaboration and change in society. The multisectoral nature of conservation and management issues has led to the development of complex and often fragmented programs and action plans, with many agencies responsible for different parts of the problem. Responsible government departments require collaboration from other government organisations at national, state, regional and local level, and even internationally.

CEPA is the means to set up enabling conditions for collaboration so that policies, incentives and regulations across sectors encourage wetland conservation and wise use. CEPA develops the relationships and learning processes underpinning innovation in institutions and organisations. This process of change entails much more than releasing information through reports and memos. Aside from other government departments, wetland conservation needs support at varying times and places from NGOs, Indigenous peoples, business and industry, scientists, farmers and fishing associations, women’s groups, youth, consumer associations and community-based groups. To work with these different groups, CEPA is crucial to building trust, understanding and shared agreements for action and to reduce conflict.

11.1 Major CEPA activities for Yanga National Park

A number of CEPA activities in Yanga National Park in recent years have greatly increased public awareness of the environmental significance of the site:

� the acquisition of Yanga Station in 2005 by the NSW Government and subsequent gazettal as a national park in 2007

� the evolution of Yanga National Park as a major focus for research on lowland floodplain ecology in NSW; major projects include:

� response of the southern bell frog to EWA

� historical extent and condition of major vegetation types in Yanga National Park

� hydrodynamic and hydrological modelling for the Lowbidgee floodplain

� waterbirds and fish survey and their responses to EWA

� trophic dynamics and organic matter and response to EWA

� surface water and groundwater gauging network.

� a number of infrastructure projects to improve EWA management, including the construction of a new bridge and regulator at Two Bridges Swamp

� a series of workshops bringing together park managers, river managers, wetland scientists and local landowners

� the employment of local people in Yanga National Park.


11.2 Important CEPA messages � Yanga National Park is a biodiversity hotspot within the arid and semi-arid south-

eastern Australia region providing a mosaic of habitats made up of lowland floodplain forests and woodlands, large lakes and temporary wetlands for 20 threatened animal species and four threatened plant species.

� Yanga National Park contains one of the largest river red gum forests in the Murray–Darling Basin, comprising around 22,000 hectares and providing a unique opportunity to maintain a connected, organised and functioning ecosystem within the NSW Riverina bioregion where fragmentation and isolation are the major stressors for biological conservation.

� Historically, the Yanga floodplain supported a large number of waterbird colonies. Considering the widespread and dramatic decline in waterbird numbers in the Murray–Darling Basin in recent years, Yanga and other parts of the Lowbidgee floodplain provide important waterbird breeding sites.

� The natural attractions and terrain in Yanga National Park make it ideal for recreational opportunities such as camping, walking, cycling, driving tours and wildlife observation.

� Alteration of flood regimes is the single most significant factor contributing to the degradation of Yanga National Park; re-establishing natural flood regimes is the key to the maintenance, rejuvenation and rehabilitation the ecosystem function of the floodplain.


Appendix 1 Plant species in Yanga National Park

Family Scientific name Common name StatusAizoaceae Mesembryanthemum nodiflorum* Small ice plant Aizoaceae Disphyma crassifolium subsp. clavellatum Aizoaceae Psilocaulon tenue* Wiry noon-flower Alismataceae Damasonium minus StarfruitAmaranthaceae Alternanthera denticulata Lesser joyweed Amaranthaceae Ptilotus nobilis Yellowtails Amaranthaceae Alternanthera spp.Amaranthaceae Ptilotus exaltatus var. exaltatus Tall mulla mulla P Anacardiaceae Schinus areira* Pepper tree Apiaceae Daucus glochidiatus Native carrot Anthericaceae Thysanotus baueri Asphodelaceae Bulbine bulbosa Bulbine lily Asphodelaceae Bulbine semibarbata Wild onion Asteraceae Acroptilon repens* Creeping knapweed Asteraceae Angianthus brachypappus Spreading cup-flower Asteraceae Aster subulatus* Wild aster Asteraceae Brachyscome ciliaris Variable daisy Asteraceae Brachyscome basaltica var. gracilis Swamp daisy Asteraceae Brachyscome dentata Asteraceae Brachyscome lineariloba Hard-headed daisy Asteraceae Calocephalus sonderi Pale beauty-heads Asteraceae Calotis cuneifolia Purple burr-daisy Asteraceae Calotis hispidula Bogan flea Asteraceae Calotis scabiosifolia Rough burr-daisy Asteraceae Calotis scabiosifolia var. scabiosifolia Asteraceae Calotis hispidula Bogan flea

Asteraceae Carduus tenuiflorus* Winged slender thistle

Asteraceae Centaurea melitensis* Maltese cockspur Asteraceae Centipeda crateriformis subsp. compacta

Asteraceae Centipeda cunninghamii Common sneezeweed

Asteraceae Centipeda minima Spreading sneezeweed

Asteraceae Centipeda thespidioides Desert sneezeweed Asteraceae Chrysocephalum apiculatum Common everlasting Asteraceae Chrysocephalum semipapposum Clustered everlasting Asteraceae Cirsium vulgare* Spear thistle Asteraceae Cotula coronopifolia* Water buttons Asteraceae Cynara cardunculus subsp. cardunculus* Asteraceae Cynara cardunculus subsp. flavescens* Asteraceae Gnephosis tenuissima Asteraceae Eclipta platyglossa Asteraceae Euchiton sphaericus


Family Scientific name Common name StatusAsteraceae Helminthotheca echioides* Ox-tongue Asteraceae Hypochaeris glabra* Smooth catsear Asteraceae Leiocarpa websteri Asteraceae Leucochrysum albicans var. tricolor Asteraceae Minuria leptophylla Asteraceae Minuria cunninghamii Asteraceae Minuria integerrima Asteraceae Olearia lepidophylla Asteraceae Onopordum acaulon* Stemless thistle Asteraceae Picris hieracioides* Hawkweed picris Asteraceae Picris spp.Asteraceae Pycnosorus pleiocephalus P Asteraceae Rhodanthe corymbiflora Small white sunray

Asteraceae Rhodanthe floribunda Common white sunray P

Asteraceae Rhodanthe pygmaea Pigmy sunray Asteraceae Rhodanthe stuartiana Asteraceae Rhodanthe tietkensii Asteraceae Senecio cunninghamii Asteraceae Senecio cunninghamii var. cunninghamii Asteraceae Senecio glossanthus Asteraceae Senecio lautus subsp. dissectifolius Asteraceae Senecio runcinifolius Tall groundsel Asteraceae Sonchus asper subsp. glaucescens* Prickly sowthistle Asteraceae Sonchus oleraceus* Common sowthistle Asteraceae Vittadinia cuneata var. hirsuta Asteraceae Vittadinia gracilis

Asteraceae Xanthium occidentale* Noogoora (cockle) burr

Asteraceae Xanthium spinosum* Bathurst burr Azollaceae Azolla filiculoides Boraginaceae Echium plantagineum* Patterson's curse Boraginaceae Halgania andromedifolia Smooth halgania Boraginaceae Heliotropium curassavicum* Smooth heliotrope Boraginaceae Heliotropium europaeum* Common heliotrope Boraginaceae Heliotropium supinum* Prostrate heliotrope Boraginaceae Plagiobothrys plurisepaleus Brassicaceae Alyssum linifolium* Flax-leaf alyssum Brassicaceae Brassica tournefortii* Mediterranean turnip Brassicaceae Cuphonotus humistratus Brassicaceae Harmsiodoxa blennodioides Brassicaceae Lepidium fasciculatum Brassicaceae Lepidium monoplocoides Winged peppercress E Brassicaceae Sisymbrium irio* London rocket Brassicaceae Phlegmatospermum cochlearinum Oval-podded cress Brassicaceae Rorippa eustylis


Family Scientific name Common name StatusBrassicaceae Rorippa laciniata Brassicaceae Sisymbrium erysimoides Smooth mustard Brassicaceae Stenopetalum sphaerocarpum Cactaceae Opuntia stricta* Campanulaceae Wahlenbergia fluminalis River bluebell Campanulaceae Wahlenbergia luteola Campanulaceae Wahlenbergia spp.Caryophyllaceae Spergularia diandra* Lesser sandspurry Caryophyllaceae Spergularia moorei* Caryophyllaceae Spergularia rubra* Sandspurry Casuarinaceae Casuarina cristata BelahCasuarinaceae Casuarina pauper BelahChenopodiaceae Atriplex eardleyae Chenopodiaceae Atriplex leptocarpa Slender-fruit saltbush Chenopodiaceae Atriplex lindleyi Chenopodiaceae Atriplex nummularia Old man saltbush Chenopodiaceae Atriplex pseudocampanulata Chenopodiaceae Atriplex pumilio Chenopodiaceae Atriplex semibaccata Creeping saltbush Chenopodiaceae Atriplex spp.Chenopodiaceae Atriplex suberecta

Chenopodiaceae Chenopodium desertorum subsp.desertorum

Chenopodiaceae Chenopodium nitrariaceum Nitre goosefoot Chenopodiaceae Chenopodium pumilio Small crumbweed Chenopodiaceae Dissocarpus paradoxus Cannonball burr Chenopodiaceae Einadia nutans Climbing saltbush Chenopodiaceae Enchylaena tomentosa Ruby saltbush Chenopodiaceae Maireana astrotricha Low bluebush Chenopodiaceae Maireana brevifolia Chenopodiaceae Maireana erioclada Chenopodiaceae Maireana georgei Chenopodiaceae Maireana pentagona Hairy bluebush Chenopodiaceae Maireana pyramidata Black bluebush Chenopodiaceae Maireana sedifolia Pearl bluebush Chenopodiaceae Maireana spp.Chenopodiaceae Malacocera tricornis Soft horns Chenopodiaceae Osteocarpum acropterum Chenopodiaceae Osteocarpum acropterum var. deminuta Chenopodiaceae Osteocarpum spp.Chenopodiaceae Rhagodia spinescens Thorny saltbush Chenopodiaceae Rhagodia ulicina Chenopodiaceae Salsola kali var. kali Chenopodiaceae Sclerolaena brachyptera Chenopodiaceae Sclerolaena birchii Galvinized burr Chenopodiaceae Sclerolaena diacantha Grey copperburr


Family Scientific name Common name StatusChenopodiaceae Sclerolaena muricata Black rolypoly Chenopodiaceae Sclerolaena muricata var. villosa Chenopodiaceae Sclerolaena obliquicuspis Chenopodiaceae Sclerolaena obliquicuspis Chenopodiaceae Sclerolaena tricuspis Giant redburr Chenopodiaceae Sclerostegia tenuis Convolvulaceae Cressa australis Crassulaceae Crassula colorata Cyperaceae Carex appressa Tall sedge Cyperaceae Cyperus gymnocaulos Cyperaceae Eleocharis acuta Common spike rush Cyperaceae Eleocharis pusilla Cyperaceae Eleocharis sphacelata Tall spike rush Cyperaceae Eleocharis spp.Eriocaulaceae Eriocaulon australasicum Austral pipewort E Euphorbiaceae Chamaesyce dallachyana Euphorbiaceae Chamaesyce drummondii Caustic weed Euphorbiaceae Phyllanthus lacunarius Fabaceae Senna form taxon 'zygophylla' Fabaceae Astragalus hamosus* Yellow milk-vetch Fabaceae Cullen pallidum Fabaceae Daviesia genistifolia Broom bitter pea Fabaceae Lotus cruentus Red-flowered lotus Fabaceae Medicago minima* Woolly burr medic Fabaceae Medicago polymorpha* Burr medic Fabaceae Medicago spp.*Fabaceae Medicago truncatula* Barrel medic Fabaceae Melilotus indicus Hexham scent Fabaceae Swainsona murrayana Slender Darling pea V Fabaceae Swainsona phacoides Fabaceae Acacia melvillei Yarran Fabaceae Acacia oswaldii MiljeeFabaceae Acacia pendula BoreeFabaceae Acacia salicina Cooba Fabaceae Acacia stenophylla River cooba Fabaceae Acacia victoriae subsp. victoriae Elegant wattle Fumariaceae Fumaria spp.*Gentianaceae Centaurium spicatum Spike centaury Geraniaceae Pelargonium australe Native storksbill Goodeniaceae Goodenia fascicularis Goodeniaceae Goodenia glauca Goodeniaceae Goodenia heteromera Goodeniaceae Goodenia pusilliflora Goodeniaceae Goodenia spp.Haloragaceae Haloragis aspera


Family Scientific name Common name StatusHaloragaceae Myriophyllum caput-medusae Cat-tail

Haloragaceae Myriophyllum propinquum Common water milfoil

Haloragaceae Myriophyllum verrucosum Red water milfoil Iridaceae Romulea rosea var. australis* Onion grass Hydrocharitaceae Vallisneria gigantea Eelweed Juncaceae Juncus acutus subsp. acutus* Sharp rush Juncaceae Juncus aridicola Juncaceae Juncus articulatus* Juncaceae Juncus flavidus Juncaceae Juncus radula Juncaceae Juncus spp.Lamiaceae Ajuga australis Austral bugle Lamiaceae Marrubium vulgare* Horehound Lamiaceae Westringia rigida Stiff westringia Lobeliaceae Pratia concolor Poison pratia Loranthaceae Amyema quandang var. quandang Loranthaceae Amyema spp.Lythraceae Lythrum hyssopifolia Hyssop loosestrife Malvaceae Hibiscus sturtii var. sturtii Malvaceae Lawrencia squamata Malvaceae Malva australiana Native hollyhock Malvaceae Malva nicaeensis* Mallow of Nice

Malvaceae Malva parviflora* Small-flowered mallow

Malvaceae Malva spp.*Malvaceae Sida corrugata Malvaceae Sida intricata Malvaceae Sida trichopoda Marsileaceae Marsilea costulifera Marsileaceae Marsilea drummondii Common nardoo Menyanthaceae Nymphoides crenata Wavy marshwort Myoporaceae Eremophila deserti Turkeybush Myoporaceae Eremophila longifolia Emu bush Myoporaceae Myoporum platycarpum subsp. platycarpumMyrtaceae Eucalyptus camaldulensis River red gum Myrtaceae Eucalyptus dumosa White mallee Myrtaceae Eucalyptus gracilis subsp. gracilis Myrtaceae Eucalyptus largiflorens Black box Myrtaceae Eucalyptus oleosa subsp. oleosa Red mallee Myrtaceae Eucalyptus socialis Red mallee Myrtaceae Melaleuca lanceolata Nitrariaceae Nitraria billardierei Dillon bush Nyctaginaceae Boerhavia dominii TarvineOleaceae Jasminum lineare Desert jasmine Onagraceae Epilobium hirtigerum


Family Scientific name Common name StatusOnagraceae Ludwigia peploides subsp. montevidensis Water primrose Oxalidaceae Oxalis perennans Plantaginaceae Plantago drummondii Plantaginaceae Plantago turrifera Plumbaginaceae Limonium lobatum* Winged sea lavender

Plumbaginaceae Limonium sinuatum* Perennial sea lavender

Poaceae Alopecurus geniculatus* Marsh foxtail Poaceae Amphibromus spp.Poaceae Austrodanthonia caespitosa Ringed wallaby grass Poaceae Austrostipa drummondii Poaceae Austrostipa nitida Poaceae Austrostipa nodosa Poaceae Austrostipa scabra subsp. scabra Poaceae Bromus catharticus* Praire grass Poaceae Bromus rubens* Red brome Poaceae Chloris truncata Windmill grass Poaceae Dactyloctenium radulans Button grass Poaceae Elymus scaber Poaceae Enneapogon avenaceus Bottle washers Poaceae Enteropogon acicularis Poaceae Eragrostis australasica Canegrass Poaceae Eragrostis cilianensis* Stinkgrass Poaceae Eragrostis dielsii Mallee lovegrass Poaceae Eragrostis setifolia NeverfailPoaceae Hordeum leporinum* Barley grass Poaceae Hordeum marinum* Sea barley grass Poaceae Lachnagrostis filiformis Poaceae Lamarckia aurea* Goldentop Poaceae Lolium perenne* Perennial ryegrass Poaceae Paspalidium jubiflorum Warrego grass Poaceae Paspalum distichum Water couch Poaceae Phalaris minor* Lesser canary grass Poaceae Phalaris paradoxa* Paradoxa grass Poaceae Phragmites australis Common reed Poaceae Poa fordeana Poaceae Polypogon monspeliensis* Annual beardgrass Poaceae Schismus barbatus* Arabian grass Poaceae Sporobolus caroli Fairy grass Poaceae Triodia scariosa Porcupine grass Poaceae Vulpia myuros f. megalura* Polygonaceae Muehlenbeckia florulenta LignumPolygonaceae Muehlenbeckia horrida Polygonaceae Persicaria decipiens Slender knotweed Polygonaceae Persicaria lapathifolia Pale knotweed Polygonaceae Persicaria orientalis* Princes feathers


Family Scientific name Common name StatusPolygonaceae Persicaria prostrata Creeping knotweed Polygonaceae Persicaria spp.Polygonaceae Polygonum arenastrum* Wireweed Polygonaceae Polygonum plebeium Small knotweed Polygonaceae Rumex crispus* Curled dock Polygonaceae Rumex spp.Polygonaceae Rumex crystallinus Shiny dock Potamogetonaceae Potamogeton crispus Curly pondweed Potamogetonaceae Potamogeton sulcatus Potamogetonaceae Potamogeton tricarinatus Floating pondweed Proteaceae Hakea leucoptera Needlewood Proteaceae Hakea leucoptera subsp. leucoptera Proteaceae Hakea tephrosperma Hooked needlewood Ranunculaceae Ranunculus inundatus River buttercup Ranunculaceae Ranunculus lappaceus Common buttercup Ranunculaceae Ranunculus pentandrus Ranunculaceae Ranunculus pentandrus var. platycarpus Ranunculaceae Ranunculus sceleratus* Celery buttercup Ranunculaceae Ranunculus spp.Ranunculaceae Ranunculus undosus Rubiaceae Asperula conferta Common woodruff

Sapindaceae Alectryon oleifolius Western rosewood, bonaree

Scrophulariaceae Gratiola pedunculata Scrophulariaceae Stemodia florulenta Bluerod Solanaceae Datura inoxia* Downy thornapple Solanaceae Lycium ferocissimum* African boxthorn Solanaceae Nicotiana glauca* Tree tobacco Solanaceae Solanum esuriale Quena

Solanaceae Solanum karsense Menindee nightshade V

Solanaceae Solanum nigrum* Black-berry nightshade

Solanaceae Solanum spp.Thymelaeaceae Pimelea microcephala subsp. microcephala

Typhaceae Typha orientalis Broad-leaved cumbungi

Urticaceae Urtica urens* Small nettle Zygophyllaceae Zygophyllum ammophilum Sand twinleaf Zygophyllaceae Zygophyllum aurantiacum Shrubby twinleaf Zygophyllaceae Zygophyllum crenatum Lobed twinleaf Zygophyllaceae Zygophyllum glaucum Pale twinleaf Zygophyllaceae Zygophyllum iodocarpum Violet twinleaf

* Exotic species

P, protected; E, endangered; V, vulnerable


Appendix 2 Bird species in Yanga National Park

Family Scientific name Common name StatusMeliphagidae Acanthagenys rufogularis Spiny-cheeked honeyeater P Acanthizidae Acanthiza apicalis Inland thornbill P Acanthizidae Acanthiza chrysorrhoa Yellow-rumped thornbill P Acanthizidae Acanthiza nana Yellow thornbill P Acanthizidae Acanthiza uropygialis Chestnut-rumped thornbill P Accipitridae Accipiter cirrocephalus Collared sparrowhawk P Accipitridae Accipiter fasciatus Brown goshawk P Sylviidae Acrocephalus australis Australian reed-warbler P Aegothelidae Aegotheles cristatus Australian owlet-nightjar P Alcedinidae Alcedo azurea Azure kingfisher P Anatidae Anas castanea Chestnut teal P Anatidae Anas gracilis Grey teal P Anatidae Anas rhynchotis Australasian shoveler P Anatidae Anas superciliosa Pacific black duck P Anhingidae Anhinga melanogaster Darter P Anatidae Anser sp.* Domestic goose U Anseranatidae Anseranas semipalmata Magpie goose V Meliphagidae Anthochaera carunculata Red wattlebird P Motacillidae Anthus australis Australian pipit P Acanthizidae Aphelocephala leucopsis Southern whiteface P Apodidae Apus pacificus Fork-tailed swift P Accipitridae Aquila audax Wedge-tailed eagle P Ardeidae Ardea alba Great egret P Ardeidae Ardea intermedia Intermediate egret P Ardeidae Ardea pacifica White-necked heron P Ardeidae Ardea/Egretta sp. Unidentified egret P Artamidae Artamus cinereus Black-faced woodswallow P Artamidae Artamus cyanopterus Dusky woodswallow P Artamidae Artamus leucorynchus White-breasted woodswallow P Artamidae Artamus personatus Masked woodswallow P Artamidae Artamus superciliosus White-browed woodswallow P Anatidae Aythya australis Hardhead P Psittacidae Barnardius zonarius barnardi Mallee ringneck P Anatidae Biziura lobata Musk duck P Ardeidae Botaurus poiciloptilus Australasian bittern V Ardeidae Bubulcus ibis Cattle egret P Burhinidae Burhinus grallarius Bush stone-curlew E Cacatuidae Cacatua galerita Sulphur-crested cockatoo P Cacatuidae Cacatua sanguinea Little corella P Scolopacidae Calidris acuminata Sharp-tailed sandpiper P Cuculidae Chalcites basalis Horsfield's bronze-cuckoo P Cuculidae Chalcites osculans Black-eared cuckoo P Charadriidae Charadrius ruficapillus Red-capped plover P


Family Scientific name Common name StatusAnatidae Chenonetta jubata Australian wood duck P Hirundinidae Cheramoeca leucosterna White-backed swallow P Ptilonorhynchidae Chlamydera maculata Spotted bowerbird P Laridae Chlidonias hybridus Whiskered tern P Sylviidae Cincloramphus cruralis Brown songlark P Sylviidae Cincloramphus mathewsi Rufous songlark P Eupetidae Cinclosoma castanotus Chestnut quail-thrush V Accipitridae Circus approximans Swamp harrier P Accipitridae Circus assimilis Spotted harrier P Cisticolidae Cisticola exilis Golden-headed cisticola P Recurvirostridae Cladorhynchus leucocephalus Banded stilt P Climacteridae Climacteris picumnus Brown treecreeper V Pachycephalidae Colluricincla harmonica Grey shrike-thrush P Columbidae Columba livia* Rock dove U Campephagidae Coracina maxima Ground cuckoo-shrike P Campephagidae Coracina novaehollandiae Black-faced cuckoo-shrike P Campephagidae Coracina papuensis White-bellied cuckoo-shrike P Corcoracidae Corcorax melanorhamphos White-winged chough P Corvidae Corvus bennetti Little crow P Corvidae Corvus coronoides Australian raven P Corvidae Corvus mellori Little raven P Phasianidae Coturnix pectoralis Stubble quail P Phasianidae Coturnix ypsilophora Brown quail P Artamidae Cracticus nigrogularis Pied butcherbird P Cuculidae Cuculus pallidus Pallid cuckoo P Anatidae Cygnus atratus Black swan P Alcedinidae Dacelo novaeguineae Laughing kookaburra P Neosittidae Daphoenositta chrysoptera Varied sittella P Anatidae Dendrocygna eytoni Plumed whistling-duck P Dicaeidae Dicaeum hirundinaceum Mistletoebird P Casuariidae Dromaius novaehollandiae Emu P Ardeidae Egretta garzetta Little egret P Ardeidae Egretta novaehollandiae White-faced heron P Accipitridae Elanus axillaris Black-shouldered kite P Charadriidae Elseyornis melanops Black-fronted dotterel P Meliphagidae Entomyzon cyanotis Blue-faced honeyeater P Cacatuidae Eolophus roseicapillus Galah P Meliphagidae Epthianura albifrons White-fronted chat P Meliphagidae Epthianura tricolor Crimson chat P Charadriidae Erythrogonys cinctus Red-kneed dotterel P Caprimulgidae Eurostopodus argus Spotted nightjar P Falconidae Falco berigora Brown falcon P Falconidae Falco cenchroides Nankeen kestrel P Falconidae Falco longipennis Australian hobby P Falconidae Falco peregrinus Peregrine falcon P


Family Scientific name Common name StatusFalconidae Falco subniger Black falcon P Pachycephalidae Falcunculus frontatus Eastern shrike-tit P Rallidae Fulica atra Eurasian coot P Scolopacidae Gallinago hardwickii Latham's snipe P Rallidae Gallinula tenebrosa Dusky moorhen P Rallidae Gallinula ventralis Black-tailed native-hen P Rallidae Gallirallus philippensis Buff-banded rail P Columbidae Geopelia placida Peaceful dove P Acanthizidae Gerygone fusca Western gerygone P Dicruridae Grallina cyanoleuca Magpie-lark P Meliphagidae Grantiella picta Painted honeyeater V Artamidae Gymnorhina tibicen Australian magpie P Accipitridae Haliaeetus leucogaster White-bellied sea-eagle P Accipitridae Haliastur sphenurus Whistling kite P Accipitridae Hieraaetus morphnoides Little eagle P Recurvirostridae Himantopus himantopus Black-winged stilt P Hirundinidae Hirundo neoxena Welcome swallow P Ardeidae Ixobrychus minutus Little bittern P Campephagidae Lalage tricolor White-winged triller P Laridae Larus novaehollandiae Silver gull P Meliphagidae Lichenostomus leucotis White-eared honeyeater P Meliphagidae Lichenostomus ornatus Yellow-plumed honeyeater P Meliphagidae Lichenostomus virescens Singing honeyeater P Accipitridae Lophoictinia isura Square-tailed kite V Anatidae Malacorhynchus membranaceus Pink-eared duck P Maluridae Malurus cyaneus Superb fairy-wren P Maluridae Malurus lamberti Variegated fairy-wren P Maluridae Malurus leucopterus White-winged fairy-wren P Maluridae Malurus splendens Splendid fairy-wren P Meliphagidae Manorina flavigula Yellow-throated miner P Meliphagidae Manorina melanocephala Noisy miner P Sylviidae Megalurus gramineus Little grassbird P Petroicidae Melanodryas cucullata Hooded robin V Meliphagidae Melithreptus brevirostris Brown-headed honeyeater P Psittacidae Melopsittacus undulatus Budgerigar P Meropidae Merops ornatus Rainbow bee-eater P Petroicidae Microeca fascinans Jacky winter P Accipitridae Milvus migrans Black kite P Alaudidae Mirafra javanica Horsfield's bushlark P Dicruridae Myiagra inquieta Restless flycatcher P Psittacidae Neophema chrysostoma Blue-winged parrot P Strigidae Ninox boobook Southern boobook P Strigidae Ninox connivens Barking owl V Psittacidae Northiella haematogaster Blue bonnet P Ardeidae Nycticorax caledonicus Nankeen night heron P


Family Scientific name Common name StatusCacatuidae Nymphicus hollandicus Cockatiel P Columbidae Ocyphaps lophotes Crested pigeon P Pachycephalidae Oreoica gutturalis Crested bellbird P Oriolidae Oriolus sagittatus Olive-backed oriole P Anatidae Oxyura australis Blue-billed duck V Pachycephalidae Pachycephala pectoralis Golden whistler P Pachycephalidae Pachycephala rufiventris Rufous whistler P Pardalotidae Pardalotus punctatus Spotted pardalote P Pardalotidae Pardalotus punctatus Yellow-rumped pardalote P Pardalotidae Pardalotus striatus Striated pardalote P Passeridae Passer domesticus* House sparrow U Pelecanidae Pelecanus conspicillatus Australian pelican P Charadriidae Peltohyas australis Inland dotterel P Hirundinidae Petrochelidon ariel Fairy martin P Hirundinidae Petrochelidon nigricans Tree martin P Petroicidae Petroica goodenovii Red-capped robin P Petroicidae Petroica phoenicea Flame robin P Phalacrocoracidae Phalacrocorax carbo Great cormorant P Phalacrocoracidae Phalacrocorax melanoleucos Little pied cormorant P Phalacrocoracidae Phalacrocorax sulcirostris Little black cormorant P Phalacrocoracidae Phalacrocorax varius Pied cormorant P Columbidae Phaps chalcoptera Common bronzewing P Meliphagidae Philemon citreogularis Little friarbird P Meliphagidae Phylidonyris albifrons White-fronted honeyeater P Threskiornithidae Platalea flavipes Yellow-billed spoonbill P Threskiornithidae Platalea regia Royal spoonbill P Psittacidae Platycercus adscitus eximius Eastern rosella P Psittacidae Platycercus elegans Crimson rosella P Psittacidae Platycercus elegans flaveolus Yellow rosella P Meliphagidae Plectorhyncha lanceolata Striped honeyeater P Threskiornithidae Plegadis falcinellus Glossy ibis P Podargidae Podargus strigoides Tawny frogmouth P Podicipedidae Podiceps cristatus Great crested grebe P Podicipedidae Poliocephalus poliocephalus Hoary-headed grebe P

Psittacidae Polytelis anthopeplus monarchoides

Regent parrot (eastern subspecies) E

Psittacidae Polytelis swainsonii Superb parrot V Pomatostomidae Pomatostomus ruficeps Chestnut-crowned babbler P Pomatostomidae Pomatostomus superciliosus White-browed babbler P

Pomatostomidae Pomatostomus temporalis temporalis

Grey-crowned babbler (eastern subspecies) V

Rallidae Porphyrio porphyrio Purple swamphen P Rallidae Porzana fluminea Australian spotted crake P Rallidae Porzana pusilla Baillon's crake P Psittacidae Psephotus haematonotus Red-rumped parrot P Psittacidae Psephotus varius Mulga parrot P


Family Scientific name Common name StatusAcanthizidae Pyrrholaemus brunneus Redthroat V Recurvirostridae Recurvirostra novaehollandiae Red-necked avocet P Dicruridae Rhipidura albiscapa Grey fantail P Dicruridae Rhipidura leucophrys Willie wagtail P

Rostratulidae Rostratula benghalensis australis Painted snipe (Australian subspecies) E

Podicipedidae small grebe sp. Small grebe P Charadriidae small wader sp. Small waders P Acanthizidae Smicrornis brevirostris Weebill P Laridae Sterna caspia Caspian tern P Laridae Sterna nilotica Gull-billed tern P Anatidae Stictonetta naevosa Freckled duck V Glareolidae Stiltia isabella Australian pratincole P Artamidae Strepera versicolor Grey currawong P Corcoracidae Struthidea cinerea Apostlebird P Sturnidae Sturnus vulgaris* Common starling U Podicipedidae Tachybaptus novaehollandiae Australasian grebe P Anatidae Tadorna tadornoides Australian shelduck P Estrildidae Taeniopygia guttata Zebra finch P Threskiornithidae Threskiornis molucca Australian white ibis P Threskiornithidae Threskiornis spinicollis Straw-necked ibis P Alcedinidae Todiramphus pyrrhopygia Red-backed kingfisher P Alcedinidae Todiramphus sanctus Sacred kingfisher P Psittacidae Trichoglossus haematodus Rainbow lorikeet P Scolopacidae Tringa nebularia Common greenshank P Scolopacidae Tringa stagnatilis Marsh sandpiper P Muscicapidae Turdus merula* Eurasian blackbird U Turnicidae Turnix varia Painted button-quail P Turnicidae Turnix velox Little button-quail P Tytonidae Tyto alba Barn owl P Charadriidae Vanellus miles Masked lapwing P Charadriidae Vanellus tricolor Banded lapwing P

P, protected; E, endangered; U, introduced; V, vulnerable.


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