Freshwater Crayﬁ sh Surveys of Jamison and Leura Falls Creeks€¦ · The pest control operators...

Freshwater Crayfi sh Surveys of

Jamison and Leura Falls Creeks

12th and 13th May 2016

AustralianAquatic Biological

FreshwaterCrayfishSurveysofJamison&LeuraFallsCreeks2016

AustralianAquaticBiologicalP/L Page1

Report to Blue Mountains City Council

Freshwater Crayfish Surveys of Jamison and Leura Falls Creeks

12th and 13th May 2016

Prepared by Robert B McCormack

Cover photos: Background: The Giant Spiny Crayfish Euastacus spinifer Site 1 (trap 1) Jamison Creek, Wentworth Falls, 12th May 2016. Foreground: The Sydney Crayfish Euastacus australasiensis, tributary Leura Falls Creek, Katoomba 13th May 2016. © Australian Aquatic Biological P/L

www.aabio.com.au



AcknowledgementsAquatic Survey of Jamison and Leura Falls creeks was funded by Blue Mountains City Council, who are gratefully thanked for their support and interest in this project. A special thanks to Amy St Lawrence, Aquatic Systems Officer, Blue Mountains City Council for assisting with the aquatic surveys and reviewing the draft report. We would like to acknowledge Christina Day and Cecil Ellis who assisted with field surveys.

AbbreviationsAB Aberrant (Not normal, neither male nor female but both genitals) AABio Australian Aquatic Biological P/L a.s.l. Above sea level ACP Australian Crayfish Project B Box trap BMCC Blue Mountains City Council F Female M Male O Opera house trap OCL Occipital carapace length; measured from the posterior margin of the orbit to the dorsal posterior of carapace (Morgan 1986). Document Information

Citation: McCormack 2016. Freshwater Crayfish Surveys of Jamison and Leura Falls Creeks. Final Report prepared for Blue Mountains City Council by Australian Aquatic Biological P/L.

Version: 1st Draft Report issued: 23rd May 2016 Final Report issued: 21st June 2016

Recipient:

Amy St Lawrence Aquatic Systems Officer Blue Mountains City Council Locked Bag 1005 Katoomba NSW 2780

Copies issued:

Disclaimer. Every effort has been taken to provide accurate information. The information supplied reflects the status of the knowledge base to-date;

future research will likely increase this knowledge. The author accepts no liability for errors and omissions.



Contents

TableofContentsAcknowledgements .................................................................................................................... 2 Abbreviations ............................................................................................................................. 2 Contents ..................................................................................................................................... 3 Table of Figures ......................................................................................................................... 3 Executive Summary ................................................................................................................... 4 Introduction ................................................................................................................................ 4 Method ....................................................................................................................................... 5 Results ........................................................................................................................................ 6

Site 1 Jamison Creek downstream of Darwins Bridge .......................................................... 6 Site 2 Jamison Creek upstream of Armstrong Street ............................................................. 8 Site 3 Wentworth Falls Lake................................................................................................ 10 Site 4 Leura Falls Creek downstream Cascades .................................................................. 11 Site 5 Leura Falls Creek upstream of Cliff Drive ................................................................ 13 Site 6 Tributary Leura Falls Creek downstream of Stormwater Treatment System ............ 14

Discussion ................................................................................................................................ 15 Summary & recommendations ................................................................................................ 20 Further Research & Investigation ............................................................................................ 21 References ................................................................................................................................ 22 Appendices ............................................................................................................................... 23

Appendix A Site 1 Jamison Creek April 2013..................................................................... 23 Appendix B Site 2 Jamison Creek April 2013 ..................................................................... 25 Appendix C Site 3 Leura Falls Creek April 2013 ................................................................ 27

TableofFiguresFigure 1 Jamison Creek, downstream of Darwins Bridge ......................................................... 6 Figure 2 Jamison Creek upstream of Armstrong Creek............................................................. 8 Figure 3 Euastacus spinifer captured by baited Opera House Trap .......................................... 9 Figure 4 Wentworth Falls Lake ............................................................................................... 10 Figure 5 Leura Falls Creek downstream of Cascades .............................................................. 11 Figure 6 Female Euastacus australasiensis with eggs (berried) ............................................. 12 Figure 7 Leura Falls Creek upstream of Cliff Drive ................................................................ 13 Figure 8 Tributary of Leura Falls Creek .................................................................................. 14 Figure 9 Jamison Creek Euastacus spinifer with sperm deposits ............................................ 17 Figure 10 A dead and decomposing Euastacus australasiensis .............................................. 19 Figure 11 Another dead Euastacus australasiensis ................................................................. 19



ExecutiveSummaryAustralian Aquatic Biological P/L was engaged by Blue Mountains City Council to undertake aquatic biological surveys, targeting freshwater crayfish at three sites in both Jamison Creek, Wentworth Falls and Leura Falls Creek, Katoomba in May 2016. Jamison Creek at Wentworth Falls was subject to a termiticide, Bifenthrin contamination incident in July 2012. Over 1000 dead Giant Spiny Crayfish (Euastacus spinifer) were found in a two kilometre reach of Jamison Creek. In April 2013, (9 months post incident) aquatic biological surveys were conducted by Australian Aquatic Biological within Jamison Creek to gauge the recovery if any of Euastacus spinifer within the creek. At the same time the next creek west Leura Falls Creek, which is of a similar size, flow rate and height above sea level was also surveyed to provide baseline information on a similar creek unaffected by the Bifenthrin contamination incident. The May 2016 freshwater crayfish surveys of Jamison Creek, Wentworth Falls, indicated another significant improvement of the Giant Spiny Crayfish Euastacus spinifer population. The animals collected seemed healthy and abundant with the identification of adult female breeders within the stream indicating a stable, reproducing and growing creek population. This was a positive result. The May 2016 freshwater crayfish survey of Leura Falls Creek, Katoomba, indicated a significant decline of the Sydney Crayfish Euastacus australasiensis within the creek. The number of animals collected during the surveys was significantly less than the 2013 surveys. Additionally, dead adult crayfish were observed within the creek. This was a negative result. Full details of the May 2016 survey together with discussions and recommendations are presented in the following report.

IntroductionIn July 2012, over 1000 dead Giant Spiny Crayfish (Euastacus spinifer) were found in a two kilometre reach of Jamison Creek, Wentworth Falls, including within the Greater Blue Mountains World Heritage Area. A multi‐agency investigation discovered the crayfish were killed by a termiticide, Bifenthrin, and that the effects extended beyond the crayfish to the entire aquatic macroinvertebrate community. The contaminant entered the creek via a conventional stormwater drainage system of pits and pipes, which provided a direct connection between the property at which the pesticide was over‐applied and the creek 300m away. The pest control operators involved were prosecuted (St Lawrence et al. 2014). Initial impacts of the July 2012 Bifenthrin incident were catastrophic, with most aquatic macroinvertebrate families previously recorded at the creek (pre‐incident average of 17 families including 5 sensitive Ephemeroptera, Plecoptera and Trichoptera (EPT) taxa) absent from the July 2012 (post‐incident) survey. In the eighteen months since the contamination, steady improvements in aquatic macroinvertebrate diversity and abundance were observed



(by 2014 similar to pre‐incident results) and E. spinifer have recolonised the creek (St Lawrence et al. 2014). As well as having implications for the pest control industry, the incident demonstrates the dangers of having urban areas directly connected to natural waterways via conventional stormwater infrastructure (i.e. catchments with high levels of effective imperviousness) and highlights the importance of best practice water sensitive urban design, stormwater management and related education as protection for waterways (St Lawrence et al. 2014). In April 2013, (9 months post incident) aquatic biological surveys were conducted by Australian Aquatic Biological within Jamison Creek, Wentworth Falls, New South Wales (NSW). These biological surveys were targeted towards freshwater crayfish to ascertain the current condition of the Euastacus spinifer population as to whether or not it has recovered, or if other invasive non endemic species have taken advantage of the mass mortality event and infested the stream. At the same time an additional survey was conducted within Leura Falls Creek, Katoomba. This is the next creek west (approx. 5 km), of similar size and unaffected by the Bifenthrin contamination incident. The 2013 survey provided baseline information, identifying the current populations and distributions of freshwater crayfish (Family: Parastacidae) within Jamison and Leura Falls Creeks, NSW. Full results of the April 2013 aquatic surveys were presented to BMC in April 2013 (Appendix A‐C). In May 2016 broader surveys of both Jamison and Leura Falls Creeks were conducted to document the condition of the creeks and their Parastacidae populations.

MethodBaited traps are very effective at attracting freshwater crayfish and were utilized for these surveys. Traps are baited with fresh fish (pilchard) and left for approximately three hours. Five opera house and five box traps were utilized at each site and set consecutively approximately five metres apart or as ponds and pools allowed. All traps have a 90 mm steel ring entrance to prohibit air breathing animals entering; any aquatic animals captured will stay alive and can be returned to the water after identification. Animals were examined at the collection site and released after identification and documentation (sex, weight, OCL, condition). Each trap was individually labelled with a research tag numbered in series from 1‐10. Each trap position was recorded by a Garmin 64S handheld gps. All collections were authorized by the NSW DPI Fisheries under Scientific Collection Permit P05/0077‐5.0. All collections were authorized by the National Parks and Wildlife Service, under Scientific License SL100138.



ResultsAquatic biological surveys identified three species of freshwater crayfish (Family: Parastacidae) occurring in the area. Two species of freshwater crayfish, Euastacus spinifer (Heller 1865) and Euastacus australasiensis (Milne Edwards 1837) are endemic in the region. The yabby Cherax destructor (Clark 1936) is a non indigenous invasive species. In April 2013 (9 months post mass mortality incident) two sites in Jamison Creek were surveyed each with 10 baited traps/site. A total of 14 E. spinifer were captured at site 1 (appendix A) and a total of 5 E. spinifer were captured at site 2 (appendix B). In May 2016 (46 months post mass mortality incident) the same 2 sites in Jamison Creek were resurveyed. This time a total of 27 E. spinifer were captured at site 1 and a total of 15 E. spinifer were captured at site 2 (see survey results below).

Site1JamisonCreekdownstreamofDarwinsBridge

Figure 1 Jamison Creek, downstream of Darwins Bridge

Site 1 Jamison Creek downstream of Darwins Bridge 10 am-1.30 pm 12/05/2016

Trap No.

Species Sex OCL mm

Weight gram

Comment

Latitude: S33°42.789' Longitude: E150°22.471' Height: 858 m a.s.l 1 O Euastacus spinifer F 26.31 9.12 1 O Euastacus spinifer M 53.21 74.0 1 O Euastacus spinifer F 90.91 281.0 Mature sperm deposit (Photo) 1 O Euastacus spinifer F 70.79 166.0 Mature sperm deposit (Photo)



1 O Galaxias olidus 1 only Latitude: S33°42.767' Longitude: E150°22.461' Height: 859

2 B Euastacus spinifer M 32.66 18.47 2 B Euastacus spinifer F 45.5 46.16 2 B Euastacus spinifer M 45.83 47.9 Fresh moult 2 B Euastacus spinifer F 56.07 74.93

Latitude: S33°42.759' Longitude: E150°22.458' Height: 859

3 O Euastacus spinifer F 40.06 31.07 3 O Euastacus spinifer F 40.18 32.58 3 O Euastacus spinifer M 39.05 30.03 3 O Euastacus spinifer AB 27.66 38.18 Fresh moult 3 O Euastacus spinifer F 48.86 48.75 Fresh moult 3 O Euastacus spinifer F 39.91 30.70 3 O Euastacus spinifer M 28.9 10.9 Fresh moult 3 O Galaxias olidus 3 only (Scoop)

Latitude: S33°42.754' Longitude: E150°22.458' Height: 860 m

4 B Euastacus spinifer M 53.07 71.0 4 B Galaxias olidus 2 only


5 O NOTHING Latitude: S33°42.748' Longitude: E150°22.464' Height: 864 m

6 B Euastacus spinifer F 31.04 15.17 6 B Galaxias olidus 1 only


7 O Euastacus spinifer F 50.66 63.0 7 O Euastacus spinifer AB-M 61.01 115.0 7 O Euastacus spinifer F 41.23 31.84 1 regenerating claw




9 O Euastacus spinifer F 62.52 107.0 9 O Euastacus spinifer M 65.5 134.0


10 B Euastacus spinifer F 47.21 52.11 10 B Euastacus spinifer M 38.96 24.93 10 B Euastacus spinifer M 47.91 46.94 10 B Euastacus spinifer M 20.55 4.55 10 B Galaxias olidus 10 only



Site2JamisonCreekupstreamofArmstrongStreet

Figure 2 Jamison Creek upstream of Armstrong Creek

Site 2 Jamison Creek upstream of Armstrong Street 10.30 am – 2.30 pm 12/05/2016 Trap No.

Species Sex OCL mm

Weight gram

Comment

Latitude: S33°42.915' Longitude: E150°22.500' Height: 846 m 1 O Euastacus spinifer F 85.56 265.0 Mature, clean, ready to breed


2 B NOTHING Latitude: S33°42.910' Longitude: E150°22.503' Height: 847 m

3 O Euastacus spinifer F 38.24 26.56 3 O Galaxias olidus 7 only





5 O Euastacus spinifer AB 45.07 39.16 5 O Euastacus spinifer M 50.53 63.80 Fresh moult 5 O Euastacus spinifer M 37.37 38.76 5 O Euastacus spinifer F 34.40 29.69 5 O Galaxias olidus 6 only




7 O Euastacus spinifer F 63.45 109.0 Fresh moult 7.O Euastacus spinifer M 65.29 138.0




9 O Euastacus spinifer M 37.90 28.25 9 O Euastacus spinifer F 63.11 114.0 Fresh moult 9 O Euastacus spinifer F 52.83 67.0 9 O Euastacus spinifer F 58.98 1O6.0 9 O Euastacus spinifer M 39.78 33.40


10 B NOTHING

Figure 3 Euastacus spinifer captured by baited Opera House Trap



Site3WentworthFallsLake

Figure 4 Wentworth Falls Lake

Site 3 Wentworth Falls Lake 11.30 am – 3.30 pm 12/05/2016 Trap No.

Species Sex OCL mm

Weight gram

Comment

Latitude: S33°42.350' Longitude: E150°21.959' Height: 873 m 1 O Cherax destructor 6 only 92 total


2.B Cherax destructor 6 only 97 total Latitude: S33°42.354' Longitude: E150°21.946' Height: 873 m

3 O Cherax destructor 1 only 12 Latitude: S33°42.355' Longitude: E150°21.935' Height: 874 m

4 O Euastacus australasiensis

M 61.69 134.00


5 B Cherax destructor 1 only 7.00 5 B Euastacus

australasiensis Juv 12.00


6 B NOTHING







10 O Cherax destructor F 35.78 27.6 Hand-under root ball Additional surveys in 2016 identified both Euastacus australasiensis and non indigenous Cherax destructor in Wentworth Falls Lake above Jamison Creek. Additional broader surveys of Leura Falls Creek were also conducted.

Site4LeuraFallsCreekdownstreamCascades

Figure 5 Leura Falls Creek downstream of Cascades

Site 4 Leura Falls Creek downstream Cascades 10 am-1.30 pm 13/05/2016 Trap No.

Species Sex OCL mm

Weight gram

Comment





2 B Galaxias olidus 1 only Latitude: S33°43.220' Longitude: E150°19.372' Height: 892 m

3 O Galaxias olidus 1 only Latitude: S33°43.203' Longitude: E150°19.388' Height: 894 m

4 B Euastacus australasiensis

M 15.95 2.32 Juvenile



F 62.84 124.6 Berried-burnt orange in colour




F 65.39 130.7 Soft shell





F 24.34 7.81

Figure 6 Female Euastacus australasiensis with eggs (berried)



Site5LeuraFallsCreekupstreamofCliffDrive

Figure 7 Leura Falls Creek upstream of Cliff Drive

Site 5 Leura Falls Creek upstream of Cliff Drive 10.30 am – 2.45 pm 13/05/2015 Trap No.

Species Sex OCL mm

Weight gram

Comment

Latitude: S33°43.139' Longitude: E150°19.471' Height: 911 m 1 O Euastacus

australasiensis AB 40.33 30.85



F 40.0 25.75 1 Claw - soft shell



M 50.41 68.34


F 41.44 33.20 Fresh moult




M 47.24 56.42






M 37.88 29.17




F 35.98 21.33


10 B NOTHING

Site6TributaryLeuraFallsCreekdownstreamofStormwaterTreatmentSystem

Figure 8 Tributary of Leura Falls Creek



Site 6 Tributary Leura Falls Creek Downstream of Stormwater Treatment System 11.15 am – 3.15 pm 13/05/2016 Trap No.

Species Sex OCL mm

Weight gram

Comment

Latitude: S33°42.905' Longitude: E150°19.009' Height: 958 m 1 B NOTHING



3 NOTHING Latitude: S33°42.915' Longitude: E150°19.054' Height:954 m

4 NOTHING Latitude: S33°43.019' Longitude: E150°19.141' Height: 941 m

5 Euastacus australasiensis

M 61.37 138


6 NOTHING At site 5 Leura Falls Creek upstream of Cliff Drive in 2013 a total of 22 Euastacus australasiensis were captured. The repeat survey of same site in 2016 captured a total of only 7 crayfish indicating a significant reduction in the total population.

Water Quality Test Results

Date Site Crayfish survey site

Temp ˚C

Conductivity (ms/cm)

DO mg/L

pH Salinity PSS

DO % Turbidity NTU

12/5/2016 Jamison Creek @ Darwin Bridge

1 - first set of traps at Jamison

10.61 0.057 8.14 6.28 0.03 81.7 7

12/5/2016 Wentworth Falls Lake @ western inflow channel

3 - Wentworth Falls Lake

10.25 0.06 4.41 5.86 0.03 43.8 7.1

13/5/2016 Leura Falls Creek @ above Cliff Drive

5 - Leura Falls Creek

11.98 0.085 8.59 6.88 0.04 88.5 9.7

13/5/2016 Trib Leura Falls Creek @ cnr Vale & York Streets

6 - Trib Leura Falls Creek

13.12 0.127 5.51 6.19 0.06 58.1 8

DiscussionJamison Creek above Wentworth Falls can be divided into 3 separate habitat types. Smaller feeder streams and swamps above Wentworth Falls Lake, Wentworth Falls Lake and Jamison Creek below the dam wall. The 2016 survey indicates the following distribution of freshwater crayfish within this system.



Euastacus australasiensis in the smaller feeder streams and swamps above the Lake

Cherax destructor within Wentworth Falls Lake

Euastacus spinifer in the main trunk of Jamison Creek below the Lake

Euastacus australasiensis seems restricted to the smaller feeder streams and swamps feeding Wentworth Falls Lake. This is a relatively small area with the population density unknown at this time.

Cherax destructor seems restricted to Wentworth Falls Lake. The blue claw yabby Cherax destructor is a native of the Murray Darling drainage basin in the interior of south‐eastern Australia. In New South Wales (NSW) the species naturally occurs west of the Great Dividing Range but recently, it has become established in eastern parts of NSW, outside of its natural range. The potential threats and translocation of this species into eastern NSW was first documented at 20 sites by Coughran et al. (2009). McCormack, R.B., 2014, documents a further 52 translocation sites recorded to 2014 and supplies information on interactions with eastern Euastacus species warning of the danger this invasive species poses.

Unlike the endemic freshwater crayfish species, C. destructor grows fast, matures early, breeds frequently and has a shorter gestation period. These are traits that equip it to potentially out‐compete the endemic freshwater crayfish. Their rapid proliferation, aggressive disposition and invasive habits tend to rapidly displace the endemic eastern crayfish (McCormack 2014). The NSW Fisheries Scientific Committee has listed ‘The introduction of fish to fresh waters within a river catchment outside their natural range’ as a Key Threatening Process (KTP) under the Fisheries Management Act 1994 (FM Act). The yabby, C. destructor is included in the definition of ‘fish’ under the FM Act and hence the impact on native freshwater crayfish would be covered by the existing KTP. (Leishman pers. comm. 2012: Gilligan pers. comm. 2012).

The translocated Cherax destructor population within the Lake pose a significant threat to the endemic Euastacus species. There were grave concerns that the July 2012 Bifenthrin incident resulting in a mass mortality of the Jamison Creek Euastacus population would result in allowing an opportunistic invasive species like C. destructor to establish a viable population preventing the re‐establishment of an endemic Euastacus population. These fears have, however, fortunately proved to be unfounded.

Results of the April 2013 survey (9 months post incident) of Jamison creek indicated the re‐establishment of Euastacus spinifer downstream of the Bifenthrin contamination source, without the presence of any C. destructor.

Factors believed to have assisted recovery include the presence of good‐condition, pesticide‐unaffected tributary streams, allowing for rapid re‐recruitment into the main trunk of Jamison Creek. Unaffected populations above the incident input site, allowing downstream colonization post incident. Inputs to the creek and its tributaries of high quality groundwater (via Blue Mountains Swamps and Wentworth Falls Lake) are also believed to have offset ongoing urban impacts and facilitated the re‐establishment of a ‘healthy’ assemblage of aquatic biodiversity (St Lawrence et al. 2014).



Euastacus spinifer is placed within the giant spiny crayfish group and can attain a large size of 116 mm occipital carapace length (OCL) and weight of 1000 grams (McCormack 2012). The species prefers flowing water and is widely distributed in NSW being a robust and prolific species but relatively slow growing taking a minimum of 8 years for females to reach sexual maturity at lower altitudes (350 m) (Turvey, P and Merrick, J.R. 1997). In Jamison Creek at higher altitude and cooler water would see female sexual maturity occurring at approximately 9‐10 years of age.

Most of the streams in the region have Euastacus australasiensis as the dominant species at the top of the catchment and further downstream as the flow and depth increases Euastacus spinifer occurs. This was not the case with Jamison Creek which was an unexpected result. Typically juvenile Euastacus spinifer only occur within 200 m of sexually mature females. These females have strict habitat requirements, demanding permanent, deep pools <1 m. Jamison Creek is supplied by swamps and groundwater plus a lake (Wentworth Falls Lake) in the upper catchment providing a constant environmental flow into Jamison Creek.

Wentworth Falls Lake was created by the damming of Jamison Creek to supply water for the steam railway. The Lake is now home to native and introduced waterfowl, native fish such as Gudgeons, and water bugs including freshwater crayfish, freshwater shrimp and dragonfly nymphs. It is also a popular picnic spot, with barbeque facilities and children’s play equipment (BMC 2016).

Jamison Creek has a number of deep pools (< 1 m) suitable for breeding females. The May 2016 survey captured mature females post breeding with sperm deposits (spermataphores) attached to their fourth pereopods indicating they would lay eggs within the next 24 hours or so. This was an excellent result indicating a stable population currently within the stream.

Figure 9 Jamison Creek Euastacus spinifer with sperm deposits



Jamison Creek survey results from 2013 and 2016 indicate a steady increase in the Euastacus spinifer population after the 2012 mass mortality event.

At site 1 Jamison Creek in 2013 a total of 14 Euastacus spinifer were captured. The repeat survey of same site in 2016 captured a total of 27 indicating a significant growth in the total population.

Site 2, Jamison Creek in 2013 a total of 5 Euastacus spinifer were captured. The repeat survey of same site in 2016 captured a total of 15, again indicating a growth in the total population

Healthy populations of Mountain Galaxias Galaxias olidus were observed and collected in Jamison Creek.

Leura Falls Creek at Katoomba is the next creek west (approximately 5 km) from Jamison Creek, it is of a similar size, height and flow. Euastacus spinifer were absent within this creek, only Euastacus australasiensis was present. The Sydney Crayfish Euastacus australasiensis is an intermediate group crayfish that is shy and elusive (McCormack 2012). Unlike E. spinifer their burrow systems are extensive and intricate, extending well back from the stream edge into the forest floor. A large percentage of their burrow system is unflooded and unconnected to the flowing creek waters.

This creek although of similar size, flow and height above sea level does not have any deep pools suitable for Euastacus spinifer adults. Additionally, its flow rate is subject to fluctuation being more dependent on rainfall with smaller groundwater inflows.

At site 5 Leura Falls Creek upstream of Cliff Drive in 2013 a total of 22 Euastacus australasiensis were captured. The repeat survey of same site in 2016 captured a total of only 7 crayfish indicating a significant reduction in the total population.

This result was unexpected and alarming. Surveys of the greater Leura Falls Creek system on the 13/05/2016 discovered two dead adult Euastacus australasiensis. Death of adult crayfish are rare events and to find 2 mortalities on the same day in a relatively small section of stream is exceptional. Mortality of juvenile Euastacus has been documented after storm events (Furse et al. 2012) but adult crayfish are usually unaffected, additionally, no storm events have been recorded in the area for several weeks.

One female Euastacus australasiensis carrying eggs (berried) was captured in the creek which was a good sign (fig 6). However, the brood she was carrying was relatively small. This could be caused by any number of problems but bottom line, it indicates that something went wrong and the breeding process was only 50% successful. Conclusions can’t be drawn from one poor breeding result, but another anecdotal question mark for this stream.



Figure 10 A dead and decomposing Euastacus australasiensis

One dead large adult Euastacus australasiensis was found near trap 9 at site 4. This crayfish was decomposing (fig 10) so death had occurred sometime prior. The second mortality was discovered on the stream bank between trap 3 & 4 at site 5 (fig 11). This was a fresh crayfish and death had occurred within the last 12 hours or so. The carcass had been partly eaten but whether this was the cause of death or occurred after death is unknown.

Figure 11 Another dead Euastacus australasiensis



Unlike Jamison Creek where large schools of both Galaxias olidus (Mountain galaxias) and Retropinna semoni (Australian Smelt) were captured and observed, Leura Falls Creek seemed mostly absent of these native fish species with only the odd Galaxias olidus being observed.

Leura Falls Creek is a well known habitat area for E. australasiensis, being listed in the species redescription by Morgan 1997. Morgan also makes specific mention of specimens from Wentworth Falls and Katoomba as being readily distinguishable, lacking thoracic spines, while they are usually present on coastal specimens. Overcollection of specimens by collectors and recreational fishers is a major threat to this species.

Leura Falls Creek is a high tourist area with tens of thousands of people walking the tracks beside the creek each year or tramping through the stream, this human activity is having a noticeable impact on the local fauna of the fragile creek ecosystems. Footprints, broken vegetation, disturbed rocks and logs plus litter were all observed during our creek surveys and the problem was most prominent around the cascades where one of the dead crayfish was discovered.

Freshwater crayfish have the potential to act as a rapid bioindicator of human impacts (Hardiman & Burgin, 2010). Blue Mountains City Council currently conducts regular sampling of macroinvertebrates, based on the AUSRIVAS protocol for collecting and processing samples in NSW (Department of Environment and Conservation, 2004). It would be interesting to review macroinvertebrate records for Leura Falls Creek.

Freshwater Euastacus crayfish are long lived compared to other freshwater invertebrates that are currently used to gauge stream health (Honan & Mictchell 1995, Turvey & Merrick 1997, McCormack 2012). Euastacus australasiensis require 7‐10 years to reach sexual maturity and then lives for another 10‐30 years or more.

Although tourist and recreational activity can be allocated as an impact on E. australasiensis populations around the Cascades, this is not the case at Site 5 above Cliff Drive. Here there is little or no human interaction.

Upper Leura Fall Creek catchment is a highly urbanized one. Leura Falls Creek flows through Blue Mountains City Council lands and into the Greater Blue Mountains National Park which was inscribed on the World Heritage List in 2000. Water from the creek ultimately flows downstream through the Park to Sydney’s drinking water supply, Warragamba Dam. Anything that impacts the Euastacus population within the creek ultimately impacts Sydney’s drinking water supply.

Summary&recommendationsThere is a desperate need to better understand the Leura Falls Creek Euastacus australasiensis population decline and ascertain the current threat to a species that up till now was thriving.

Further investigation of the water quality in Leura Falls Creek is essential.



Contamination of Leura Fall Creek that could impact on Euastacus populations could occur from any number of sources, stormwater inflows, raw sewage overflow, leaking or overflowing septic tanks or leaking sewer lines. We recommended more intensive water testing to determine if sewer contamination with associated chemicals and detergents is impacting the creek.

Investigation of the termiticide Bifenthrin contamination incident in Jamison Creek revealed there had been a number of prior incidents (with no reported fish or crayfish kills) from different parts of the Jamison Creek catchment and raised questions about how frequently this pesticide is polluting natural waterways (St Lawrence 2014). We recommend additional testing of Leura Falls Creek for Bifenthrin contamination.

Ongoing regular monitoring and surveying of the creek to document mortalities is essential.

Erection of signage advising visitors of the natural wonder of these amazing crayfish, their presence and advising of their protected status.

Micro chipping of the Euastacus population would also provide long term information or the species movement, growth and survival. Small microchips similar to those used to identify dogs and cats can be inserted into freshwater crayfish. This would be a long term project with information on individual crayfish collected and update over the next 10, 20, 30 or more years as these are a very long lived species. Microchipped animals also provide valuable information even in death as the chips are still functional so animals that have died well upstream and washed down by storm events can be checked and information is available on where they normally habitate, etc.

FurtherResearch&InvestigationAfter issue of the draft report investigation into historical water quality records for Leura Falls Creek revealed the following. A study conducted during October and November 2015 by WaterNSW and the Centre for Aquatic Pollution Identification and Management found a range of contaminants in the water and sediment of Leura Falls Creek, indicating pollution from a variety of sources. A total of 8 pesticides were detected at Leura Falls Creek, including two synthetic pyrethroid insecticides (bifenthrin and permethrin) found at levels that may cause toxicity to aquatic life. Other toxicants including PAHs, TPHs and trace metals were also found at concentrations potentially toxic to aquatic life. Evidence of sewer leaks was recorded, with high E. coli and human Bacteroides levels found in some samples (Sharp et al, 2016).



ReferencesBlue Mountains City Council 2016. Website – Wentworth Falls Lake. http://www.bmcc.nsw.gov.au/sustainableliving/environmentalinformation/wentworthfallslake/

Department of Environment and Conservation (DEC) NSW. (2004). NSW Australian River Assessment System (AUSRIVAS) Sampling and Processing Manual, DEC, Sydney.

Furse, J.M., Wild, C. and Coughran, J. 2012. Report of a mass mortality of Euastacus valentulus (Decapoda: Parastacidae) in southeast Queensland, Australia, with a discussion of the potential impacts of climate change induced severe weather events on freshwater crayfish species. Crustacean Research, Special Number 7: 13–22.

Gilligan, D. 2012. Member NSW Fisheries Scientific Committee. Personal communication.

Hardiman, N., & Burgin, S. (2010). Preliminary assessment of freshwater crayfish as environmental indicators of human impacts in canyons of the Blue Mountains, Australia. Journal of Crustacean Biology, 30(4), 770‐777

Honan, J. A., and B. D. Mitchell. 1995. Growth of the large freshwater crayfish Euastacus bispinosus Clark (Decapoda:Parastacidae). Freshwater Crayfish 10: 118‐131.

Leishman, M. 2012. Chairperson, NSW Scientific Committee, personal communication

McCormack, R.B. (2014). New records and review of the translocation of the yabby Cherax destructor into eastern drainages of New South Wales, Australia. Australian Zoologist. Volume 37 (1) 85 – 94. ISSN 0067‐2238 (Print). http://doi.org/10.7882/AZ.2014.006.

McCormack, R.B. 2012. A guide to Australia’s Spiny Freshwater Crayfish. CSIRO Publishing, Collingwood, Victoria. ISBN 978 0 643 10386 3

Morgan, G. J. 1997. Freshwater crayfish of the genus Euastacus Clark (Decapoda: Parastacidae) from New South Wales, with a key to all species of the genus. Records of the Australian Museum Supplement 23.

Sharp, S., MacMahon, D., Sharley, D. and Pettigrove, V. (2016) WNSW Pilot Study, Centre for Aquatic Pollution Identification and Management, Technical Report No. 64, University of Melbourne, Victoria, Australia.

St Lawrence, A., Wright, I.A., McCormack, R.B., Day, C., Smith, G. and Crane, B. (2014). Bifenthrin pesticide contamination: impacts and recovery at Jamison Creek, Wentworth Falls, in Vietz, G; Rutherfurd, I.D, and Hughes, R. (editors), Proceedings of the 7th Australian Stream Management Conference. Townsville, Queensland, Pages 558‐567.

Turvey, P and Merrick, J.R. (1997). Growth with age in the freshwater crayfish, Euastacus spinifer (Decapoda: Parastacidae), from the Sydney region, Australia. Proceedings of the Linnean Society of New South Wales 118, 205‐215.



Appendices

AppendixASite1JamisonCreekApril2013 SITE 1 Jamison Creek beside Charles Darwin Walk, Wentworth Falls (Kedumba-Cox-

Nepean-Hawkesbury Rv) Date: 13/ 04 /2013 Researchers RB McCormack GPS 33.71253S 150.37388E Elevation 868m Habitat description

Steep earthen banks, fern lined, loose rock, bedrock, course sand.

Stream condition

Fast flowing, clear, small crk - pools and riffles

Water Quality Time Water flow yes DO ppm 9.8 ppm Start Finish pH 7.86 DO% 96.4 % 6.30 am 9.42 am Temp 13.8 Conductivity 70.2 us Methods Salinity 34.8 ppm TDS 49.9 ppm 5 box traps Visibility 800 mm Other 5 x opera house traps

Survey Site Species RecordQty Order Family Genus Species Common name 2 Osmeriformes Galaxiidae Galaxias olidus mountain galaxias

14 Decapoda Parastacidae Euastacus spinifer spiny crayfish

Comments

SITE 1 BIOLOGICAL RECORD

ID Qty Species Sex OCL/mm Weight Comment Voucher/release A10 1 E. spinifer f 48.5 58 opera



A9 1 E. spinifer m 38.27 27 box A9 1 E. spinifer aber 46.63 45 Box – spec 4597 A8 1 E. spinifer F 58.82 108 Opera 1 E. spinifer f 61.12 92 Opera – 1 claw A7 nothing Nothing – box trap A6 E. spinifer M 65.52 127 Opera A5 nothing Nothing-box A4 1 E. spinifer F 50.4 49 1 claw -opera 1 E. spinifer m 69.86 163 1 E. spinifer Observed under trap A3 nothing A2 nothing A1 1 E. spinifer M 55.41 box 1 E. spinifer F 52 1 E. spinifer F 62.04 1 E. spinifer F 60.2 1 E. spinifer Observed beside trap 1 E. spinifer F 59.7 107 Spec 4596 2 G. olidus 45 ol Spec 4595 version creator lat lon ns1:ele ns1:name7 ns1:cmt

1.1 MapSend Lite ‐33.71258 150.374237 888.27 WP t19 A10 SITE 1 JAMISON CK

1.1 MapSend Lite ‐33.712616 150.374245 883.86 WP t20 A9











AppendixBSite2JamisonCreekApril2013 SITE 2 Jamison Creek beside Charles Darwin Walk, upstream Armstrong Rd, Wentworth

Falls (Kedumba-Cox-Nepean-Hawkesbury Rv) Date: 13/ 04 /2013 Researchers RB McCormack GPS 33.71462S 150.37477E Elevation 864 m Habitat description

Steep earthen banks, fern lined, loose rock, bedrock, course sand. Small shallow pools and riffles.

Stream condition

Fast flowing, clear, small crk,

Water Quality Time Water flow yes DO ppm 9.8 ppm Start Finish pH 7.86 DO% 94.6 % 7.30 am 11.15 am Temp 13.8 Conductivity 70.2 us Methods Salinity 34.8 ppm TDS 49.9 ppm 5 box traps Visibility 800 mm Other 5 x opera house traps

Survey Site Species RecordQty Order Family Genus Species Common name 69 Osmeriformes Galaxiidae Galaxias olidus mountain galaxias

5 Decapoda Parastacidae Euastacus spinifer spiny crayfish

12 Salmoniformes Retropinnidae Retropinna semoni Aust smelt

Comments


ID Qty Species Sex OCL/mm Weight Comment Voucher/release B10 1 E. spinifer M 34.55 21 opera B9 27 G. olidus mix box



B9 5 G. olidus mix Box – spec 4598 B9 6 R. semoni mix Box – B9 2 R. semoni mix Box – spec 4599 B8 1 E. spinifer F 57.11 Opera B7 3 G. olidus mix box B7 1 E. spinifer m 33.28 17 box trap B6 nothing Opera B5 9 G. olidus mix box B5 1 E. spinifer aber 49.91 46 box B4 nothing B3 21 G. olidus mix Box – B3 2 R. semoni mix Box – B2 nothing B1 1 E. spinifer M 56.95 82 box B1 4 G. olidus mix box B1 2 R. semoni mix box version creator lat lon ns1:ele ns1:name7 ns1:cmt

1.1 MapSend Lite ‐33.715142 150.374967 853.65 WP t29

B10 SITE 2 JAMISON CREEK

1.1 MapSend Lite ‐33.715078 150.375008 861.76 WP t30 B9











AppendixCSite3LeuraFallsCreekApril2013 SITE 3 Leura Falls Creek, upstream Cliff Drive Leura (Kedumba-Cox-Nepean-Hawkesbury

Rv) Date: 13/ 04 /2013 Researchers RB McCormack GPS 33.71875S 150.32495E Elevation 907 m Habitat description

fast flowing, clear, small crk, steep rock/concrete banks, fern lined, loose rock, bedrock, course sand. Mixture of shallow pools and riffles with some cascades above and below site.

Stream condition

Fast flowing, clear, small crk,

Water Quality Time Water flow yes DO ppm 10.6 ppm Start Finish pH 7.65 DO% 104.1 % 8.30 am 12.30 pm Temp 13.5 Conductivity 86.7 us Methods Salinity 42 ppm TDS 61.6 ppm 5 box traps Visibility 900 mm Other 5 x opera house traps

Survey Site Species RecordQty Order Family Genus Species Common name 22 Decapoda Parastacidae Euastacus australasiensis spiny crayfish

Comments


ID Qty Species Sex OCL/mm Weight Comment Voucher/release F1 1 E. australasiensis F 47.86 60 opera F1 1 E. australasiensis M 64.75 143 Opera – Spec 4600 F1 1 E. australasiensis aber 45.63 50 opera



F1 1 E. australasiensis M 47.39 52 Opera- 1 regen claw F1 1 E. australasiensis M 46.13 52 opera F1 3 E. australasiensis Mix Observed outside trap F2 nothing box F3 1 E. australasiensis mix Observed outside trap F4 nothing Box – F5 1 E. australasiensis M 42.19 39 opera F5 1 E. australasiensis F 48.45 57 Opera F5 3 E. australasiensis M 39.43 31 opera F5 1 E. australasiensis m 33.28 17 opera F6 nothing box F7 1 E. australasiensis F 52.36 75 opera F7 1 E. australasiensis M 45.43 51 opera F7 E. australasiensis F 50.77 69 opera F8 1 E. australasiensis mix Box –observed outside F9 1 E. australasiensis F 52.43 69 opera F9 1 E. australasiensis mix Observed outside trap F10 1 E. australasiensis mix Box –observed outside 1 E. australasiensis M 24.65 8 Under rock-spec 4601

version creator latitude longitude elevation ns1:name7 ns1:cmt

1.1 MapSend Lite ‐33.718925 150.324606 919.33 WP t39 F1 ‐ SITE 3 Leura Creek

1.1 MapSend Lite ‐33.718916 150.32461 919.29 WP t40 F2








1.1 MapSend Lite ‐33.718653 150.325252 922 WP t48 F10

Freshwater Crayﬁ sh Surveys of Jamison and Leura Falls Creeks€¦ · The pest control operators...

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