Stygofauna Values at the Lake Disappointment Potash Project · 2019-02-01 · Stygofauna Values at...

October 2018

Final Report

Prepared for:

Reward Minerals Limited

Stygofauna Values at the Lake

Disappointment Potash Project

Lake Disappointment Stygofauna Reward Minerals Limited

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Report Version Prepared by Rev iewed by Submitted to Client

Method Date

Draft Anton Mittra Stuart Halse email 7 July 2017

Final Anton Mittra Stuart Halse email 27 July 2017

Final V2 Anton Mittra Stuart Halse email 22 September 2017

Final V3 Anton Mittra email 25 October 2017

Final V4 Stuart Halse Anton Mittra email 15 October 2018

BEC_Lake Disappoint m ent Stygofauna Final_V4_8x18.docx This document has been prepared to the requirements of the Client and is for the use by the Client, its agents, and Bennelongia Env ironmental Consultants. Copyright and any other Intellectual Property associated with the document belongs to Bennelongia Environmental Consultants and may not be reproduced without written permission of the Client or Bennelongia. No liability or responsibility is accepted in respect of any use by a third party or for purposes other than for which the document was commissioned. Bennelongia has not attempted to verify the accuracy and completeness of information supplied by the Client. © Copyright 2015 Bennelongia Pty Ltd.

Bennelongia Pty Ltd 5 Bishop Street

Jolimont WA 6014

P: (08) 9285 8722 F: (08) 9285 8811

E: [email protected]

ABN: 55 124 110 167

Report Number: 304

Stygofauna Values at the Lake Disappointment Potash Project


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EXECUTIVE SUMMARY

Reward Minerals Limited is currently seeking approval to develop the Lake Disappointment Potash Project (the Project), approximately 138 km south of Telfer and 285 km east of Newman in the northern Little Sandy Desert. The Project will require groundwater abstraction from two proposed borefields and therefore has the potential affect any stygofauna habitat, as well as species and communities, that occur there.

Desktop review of a 100 km by 100 km area surrounding the Project found no records of stygofauna, but also no evidence of any survey having occurred, so the search area of the review was expanded to include the nearest known stygofauna communities. At least 97 species of stygofauna have been recorded in the extended search area, including nematodes, rotifers, gastropod molluscs, annelid worms, crustaceans (ostracods, copepods, syncarids, amphipods, isopods) and hexapods.

Potential stygofauna habitats in the vicinity of the Project are alluvial, colluvial, fractured sandstone and calcrete aquifers. There are two proposed process water supply borefields: the Cory Borefield will target the Gunanya sandstone fractured rock aquifer and the Northern Borefield will target the deeper units of the Tertiary cover sequence of sands, clays and sandy clays that overlies the Proterozoic basement. Regional calcretes will not be targeted for groundwater abstraction and are unlikely to be affected by drawdown.

A field survey that collected 30 samples from 15 sites (10 in proposed borefields and five from the surrounding region) confirmed the occurrence of stygofauna in the Project area, with 300 specimens of 13 species being collected. Sixteen out of 30 samples and 13 out of 15 sites yielded stygofauna, although two regional sites yielded only rotifers, nematodes and a very widespread cyclopoid copepod. Major groups recorded include oligochaetes, amphipods, syncarids, cyclopoid and harpacticoid copepods, and ostracods. The Cory Borefield appears to host more stygofauna than the Northern Borefield and the assemblages in the two borefields appear to be distinct from one another.

Overall, the documented stygofauna community at Lake Disappointment is modest compared with many areas of the Pilbara and Yilgarn. Neither borefield appears rich in stygofauna. Six of the stygofauna species collected are currently known only from the Lake Disappointment area. The distributions of two of the six species, Tubificidae sp. B03 (LD) and nr Pilbarus sp. B07, are locally extensive and include areas outside the proposed borefields and predicted zones of groundwater drawdown. While the other four species are known only from inside the proposed borefields and/or zones of predicted drawdown, it is likely that they also have more extensive ranges because of likely habitat connectivity.

The locally extensive ranges of species such as the worm Tubificidae sp. B03 (LD) and amphipod nr Pilbarus sp. B07 support the notion that other species known only from the boefields are likely to be locally widespread.


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CONTENTS Executive Summary ................................................................................................................. iii 1. Introduction .......................................................................................................................... 1 2. Background .......................................................................................................................... 1

2.1. Project Description......................................................................................................... 1 2.2. Subterranean Fauna ..................................................................................................... 1

2.2.1. Stygofauna ............................................................................................................... 4 2.3. Conservation Framework.............................................................................................. 4

3. Desktop Review ................................................................................................................... 5 3.1. Stygofauna Records ...................................................................................................... 5 3.2. Habitat Assessment........................................................................................................ 5

3.2.1. Cory Borefield ........................................................................................................... 5 3.2.2. Northern Borefield .................................................................................................... 7

4. Field Survey ........................................................................................................................... 8 4.1. Sampling Effort................................................................................................................ 8 4.2. Methods .......................................................................................................................... 8

4.2.1. Field Methods ........................................................................................................... 8 4.2.2. Laboratory Methods .............................................................................................. 10

4.3. Personnel ....................................................................................................................... 10 5. Results .................................................................................................................................. 10

5.1. Sampling Efficiency ..................................................................................................... 10 5.2. Species Distributions..................................................................................................... 13 5.3. Stygofauna Values....................................................................................................... 16

6. Potential Impacts on Stygofauna.................................................................................... 16 7. Conclusions......................................................................................................................... 19 8. References .......................................................................................................................... 20 9. Appendices ........................................................................................................................ 22 Appendix 1. Stygofauna species previously recorded in the vicinity of the Project identified through desktop review. ..................................................................................... 22 Appendix 2. Details of holes sampled for stygofauna around Lake Disappointment between 2016 and 2017. ...................................................................................................... 24 Appendix 3. Stygofauna species recorded at Lake Disappointment from October 2016 to March 2017, including collection locations of each species. ........................... 25

LIST OF FIGURES Figure 1. Location of the Project............................................................................................ 2 Figure 2. Geology (Gunanya 1:100,000 map sheet) and proposed borefield locations. ................................................................................................................................... 3 Figure 3. Conceptual hydrological model of the Cory Borefield (from Strategic Water Management 2018). .................................................................................................... 6 Figure 4. Conceptual hydrological model of the Northern Borefield (from Strategic Water Management 2018). .................................................................................................... 7 Figure 5. Locations of sites sampled for stygofauna in and around Lake Disappointment from October 2016 to June 2017.............................................................. 9 Figure 6. Collection locations of stygofauna species at Lake Disappointment between 2016 and 2017. ...................................................................................................... 14


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Figure 7. Collection locations of stygofauna species known only from within the extent of 2 m drawdown associated with the Cory Borefield. ....................................... 17 Figure 8. Collection locations of stygofauna species known only from within the extent of 5 m drawdown associated with the Northern Borefield. ................................ 18

LIST OF TABLES Table 1. Reports included in the desktop assessment. ....................................................... 5 Table 2. Summary of sampling effort for stygofauna at Lake Disappointment. ............. 8 Table 3. Stygofauna species recorded at Lake Disappointment (including regional bores) from 2016 to 2017....................................................................................................... 11

LIST OF PLATES Plate 1. Exemplar stygofauna specimens collected from Lake Disappointment and regional bores. ............................................................................................................... 12


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1. INTRODUCTION Reward Minerals Limited (Reward) is currently seeking approval to develop the Lake Disappointment Potash Project (the Project), approximately 138 km south of Telfer and 285 km east of Newman in the northern Little Sandy Desert IBRA bioregion (Trainor subregion; Figure 1). Proposed developments will involve extracting and concentrating naturally occurring potassium-rich brines underlying the Lake system to produce potassium sulphate (potash). Additional fresher water will be abstracted from subterranean aquifers to support resource production. This report combines the results of desktop review and field survey to examine the likely conservation significance of stygofauna species that may occur in the vicinity of the Project or within two proposed borefields that will supply processing water. The specific aims of the report are to:

• Describe the available stygofauna habitat; • Characterise stygofauna communities that may occur at the Project; • Determine the distributions and conservation statuses of stygofauna species collected in the

vicinity of the Project; and • Determine whether the Project will threaten the persistence of any stygofauna species.

2. BACKGROUND

2.1. Project Description Key components of the Project include brine abstraction trenches; solar evaporation ponds; salt harvesting and brine recovery facilities; and support infrastructure including roads, an airstrip, accommodation, administration offices, water supply and water treatment facilities, drainage and flood protection, power supply and telecommunication facilities. There will also be borefields to provide groundwater for resource production. The overall Project footprint, including the depth and area of potential groundwater drawdown, has not yet been finalised. Exploration has identified two prospective areas to the north of Lake Disappointment for groundwater abstraction, the Northern Borefield and the Cory Borefield (Figure 2). These areas are referred to as the proposed borefields. Up to 3.4 GL per year of fresh-to-brackish groundwater will be required for brine processing and other operations associated with the Project. Potash will be produced at a nominal rate of 400,000 tonnes per year from 63 GL per year of potash brine. The area of direct surface impacts is likely to be in the order of 3,500 ha comprising a series of solar evaporation ponds to be established on the playa surface of Lake Disappointment. The Project will have a nominal mine life of 20 years.

2.2. Subterranean Fauna Subterranean fauna comprise two groups of animals: aquatic stygofauna and air-breathing troglofauna. Both groups typically lack eyes and are poorly pigmented due to lack of light. Other characteristic morphological and physiological adaptations such as vermiform bodies, elongate sensory structures, loss of wings, increased lifespan, a shift towards K-selection breeding strategy and decreased metabolism reflect low inputs of carbon and nutrients in subterranean habitats occupied by subterranean species and their requirement to navigate enclosed spaces (Gibert & Deharveng 2002). With the exception of a few species of fish, all stygofauna species in Western Australia are invertebrates.


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Geology influences the presence, richness and distribution of subterranean fauna through its influence on lithology and, consequently, the different types of subterranean spaces in which animals may occur (Eberhard et al. 2005; Hose et al. 2015). Highly transmissive or vuggy geologies support greater assemblages of subterranean fauna, both in terms of abundance and diversity, than consolidated ones. Alluvial deposits may host subterranean fauna in interstitial spaces between sand and gravel, and these coarser sediments tend to host richer assemblages than silty or clay-rich substrates (Korbel and Hose 2011). Physical and chemical weathering of consolidated strata can also provide prospective niches for subterranean animals, including those in fissures, vugs and caves. Fluctuating groundwater levels and resulting precipitation of carbonates along the internal palaeoriver system of Western Australia has resulted in the formation of many areas of calcrete. Although classical karst formations are absent from most of the Western Australian landscape, the re-working of calcrete as a result of changing water levels has led to calcretes displaying karstic characteristics and providing excellent habitat for both stygofauna and troglofauna (Humphreys 2001). There is a very high incidence of short-range endemism amongst the Western Australian subterranean fauna owing to the poor dispersal capacity within the subterranean environment. As more work is done on subterranean fauna, it is shown many species have smaller ranges than first thought because of the existence of cryptic (or near cryptic) species within a lineage that was originally considered to be a single species.

2.2.1. Stygofauna Stygofauna commonly include earthworms, beetles, crustaceans (amphipods, isopods, copepods, ostracods and syncarids), water mites and snails. In Western Australia, surveys of alluvial and calcrete aquifers have revealed rich and endemic stygofaunal assemblages. Less transmissive geologies such as banded iron formations (BIF), saprolite, mafic and ultramafic tend not to support rich stygofaunal communities, although small numbers of species are often present (Ecologia 2009; GHD 2009). Stygofauna occur in varying salinities but are mostly found in water with conductivity of less than 25,000 mg L-1 TDS (Humphreys 2009; Hose et al. 2015).

2.3. Conservation Framework The Environmental Protection Authority (EPA) stipulates consideration of subterranean fauna as part of environmental impact assessment in Environmental Factor Guideline: Subterranean Fauna (EPA 2016a). This concern for subterranean fauna fits within the wider context of state and federal conservation legislation protecting Australia’s biota. In addition to general protection of all species, at the state level, the Wildlife Conservation 1950 and Biodiversity Conservation Act 2016 provide for the listing of species as Threatened or Priority following recommendations by the Threatened Species Scientific Committee and the Department of Biodiversity Conservation and Attractions (DBCA). Threatened species are specially protected because they are considered to be under identifiable threat of extinction, rare, or otherwise in need of protection. Priority species are possibly threatened species that do not meet survey criteria or are otherwise data deficient. Species may also be listed as Threatened at the national level, under the Environmental Protection and Biodiversity Conservation Act 1999 (EPBC Act). In addition to individual species, ecological communities may be listed as being in need of special protection at both the state and national levels. At the state level, the Minister for Environment may lis t an ecological community as being Threatened if the community is at risk of becoming totally destroyed. Ecological communities with insufficient information available to be considered as a Threatened Ecological Community, or which are rare but not currently threatened, are placed on a DBCA list and referred to as Priority Ecological Communities (PECs). Ecological communities may also be listed at the national level under the EPBC Act.


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3. DESKTOP REVIEW A previous desktop review by Bennelongia (2016) compiled habitat information and previous records of stygofauna to determine the likelihood that stygofauna occur in the vicinity of the Project. The findings of desktop review are summarised here, with additional comment on potential stygofauna habitat.

3.1. Stygofauna Records Records of subterranean fauna were compiled from the Western Australian Museum (WAM) and Bennelongia databases for a search area of 10,000 km2 surrounding the Project (defined by 22.467°S, 121.612°E and 24.748°S, 124.101°E). This search retrieved no results owing to the lack of previous stygofauna survey in the vicinity of the Project. Subsequently, a list of species from stygofauna communities nearest to the Project was compiled from published research papers and publically available environmental reports (Table 1). The full list of species recovered through desktop review is presented as Appendix 1. Table 1. Reports included in the desktop assessment.

Reference Description Company Location Relative to the Project

Bennelongia 2012 Subterranean fauna assessment for Kintyre Uranium Deposit Cameco Australia Pty Ltd 130 km NNW

Bennelongia 2014 Stygofauna monitoring at Telfer Gold Mine Newcrest Mining Ltd 190 km NNW

Halse et al. 2014 Biodiversity Survey of the Pilbara DBCA 140-300 km NW

Phoenix 2009 Subterranean fauna survey for the Davidson Creek Iron Ore Project FerrAus Ltd 210 km W

Unpublished. Ad hoc survey at Lake Carnegie DBCA 240 km S At least 97 species of stygofauna have been recorded in the extended search area, including nematodes, rotifers, gastropod molluscs, annelid worms, crustaceans (ostracods, copepods, syncarids, amphipods, isopods) and insects. Several higher order identifications were not included in the final count of species as they may belong to other recorded species, while some higher-order identifications may contain multiple species. Crustaceans were the most diverse group with at least 73 species, including 16 ostracods, 35 copepods, five syncarids, 14 amphipods and three isopods. At least 18 species of annelid worm have been recorded, as well as at least two insects, two rotifers, one snail and one nematode. The numbers of species recorded in each respective study (Table 1) were 16 at Kintyre, 39 at Telfer, 23 at Davidson Creek, 56 in the eastern section of the Pilbara Biodiversity Survey and seven at Lake Carnegie, where minimal sampling occurred.

3.2. Habitat Assessment Geological mapping at the 1:100,000 scale shows that some calcrete, alluvial and colluvial deposits occur in the area surrounding Lake Disappointment, although the proposed process water borefields do not target aquifers in these geologies. Depending on hydrological profile and water quality, the aforementioned units, particularly calcrete, are likely to provide good stygofauna habitat. Rich and distinct stygofauna communities have been recorded in calcrete aquifers throughout the Yilgarn, with species normally confined to individual calcrete bodies or clusters. Rich stygofauna assemblages have also been recorded in alluvium and colluvium in the Yilgarn and Pilbara, although the species in these geologies tend to be more widespread as a result of the more extensive and better connected nature of alluvium and colluvium.

3.2.1. Cory Borefield The Cory Borefield (Figure 2) lies within the regionally significant fractured rock aquifer of the Gunanya sandstone. The Gunanya sandstone outcrops extensively over an area of approximately 60 km2 while the proposed borefield covers approximately 11 km2. Groundwater movement within the aquifer occurs via joints and fractures that have developed as a result of several stages of deformation. Static water level (SWL) in the Cory Borefield is approximately 7.5 mbgl and salinity is approximately


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2,500 mg L-1. This shallow watertable and fresh (or subsaline) water are favourable for stygofauna, so that the porosity of the habitat is likely to be the main determinant of stygofauna occurrence. The lithological profile is dominated by the arkosic, medium-grained Gunanya sandstone with intermittent quartz veining. The basal sequence comprises sandstone with local beds of conglomerate, grit and siltstone, although this was not encountered by drilling. Sandstone and fractured sandstone strata extend to depths of 100 mbgl or more. At the northern fringe of the Cory Borefield in diamond core holes LDCH1701 and LDCH1702 (not sampled for stygofauna), a thin sequence of vuggy, poorly cemented to well cemented breccia was encountered to a depth of 16 mbgl, representing Quaternary and Tertiary fluvial activity. A conceptual model of the Cory Borefield provided in the hydrogeological assessment (Strategic Water Management 2018) is shown in Figure 3. Rapid post-rainfall recharge observed in bores LDRC1605 (not sampled for stygofauna) and LDRC1601 indicates that vertical hydraulic conductivity in the Cory Borefield is high. The responses of monitoring bores to both rainfall recharge and test pumping indicate that the connection of fractures is regional in nature and it is inferred that stygofauna habitat in the Gunanya sandstone will also be regionally continuous. Fractured rock aquifers do not typically provide prospective stygofauna habitat, tending to yield poorly in terms of both abundance and species richness (Bennelongia 2017; ecologia 2009; GHD 2009; EPA 2016c), although previous assessments of stygofauna communities in fractured rock in inland WA have predominantly been in BIF, mafic, ultramafic and granitoid geologies rather than sandstone. A hydrogeological assessment based on test pumping (Strategic Water Management 2018; SRK 2018) has predicted that, in the absence of recharge, long-term (~30 year) drawdown depths below SWL in the Corey Borefield may be up to3 m at a distance of approximately 0.5 km from each production bore, 2 m (at 2.5 km), 2.1 m (at 3 km) and 1.8 m (at 5 km). Bores in the Cory Borefield that were sampled for stygofauna are LDRC1601, LDRC1602, LDRC1602MB and Camp Bore.

Figure 3. Conceptual hydrological model of the Cory Borefield (from Strategic Water Management 2018). Geological codes: PUu = Gunanya Sandstone; Pus = sandstone, fine to medium grained, cross-bedded, local beds of quartz pebble conglomerate; and Czz = silcrete, siliceous caprock with angular quartz grains.


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3.2.2. Northern Borefield The Northern Borefield is situated approximately 27 km north of Lake Disappointment, covers an area of approximately 19 km2 (Figure 2) and targets an aquifer within the Quaternary and Tertiary sequence overlying the Broadhurst unit of the Throssell group and the Connaughton terrain. Core logs indicate three broad zones within the Quaternary and Tertiary sequence:

• Layer 1 - the upper aquifer zone (up to 26 m in thickness) comprising rounded sands and fine gravel in a clay and silt matrix that is weakly cemented in places, forming a vuggy conglomerate;

• Layer 2 - a confining layer of dense clay that according to a hydrogeological assessment (SRK 2018) effectively separates the upper and lower aquifers; and

• Layer 3 - the lower, principle target aquifer in a matrix of sands, clays and some quartzite.

SWL (upper aquifer) across the Northern Borefield is around 12 mbgl. Subsequent layers are damp from 15–20 mbgl and more significant water intersections in the target aquifer occur in the vicinity of 90 mbgl. A conceptual model of the Northern Borefield provided in the hydrogeological assessment (Strategic Water Management 2018; SRK 2018) is shown in Figure 4.

Figure 4. Conceptual hydrological model of the Northern Borefield (from Strategic Water Management 2018). The Northern Borefield will target a different aquifer to that of the Cory Borefield. Holes LDHC1701 and LDHC1702 (Figure 2) drilled for geological control across the borefields, showed poor aquifer connection and exploration drilling between the two borefields resulted in predominantly low-flow bores. Abstraction from one borefield is unlikely to impact water levels in the other. Groundwater electrical conductivity across the Northern Borefield varies with depth from about 400–600 µS cm-1 in the upper aquifer to about 14,000 µS cm-1 in the target aquifer. Conductivities recorded during stygofauna field survey were 310–3,370 µS cm-1. This is well within the salinity range in which stygofauna are abundant. Bores in and around the Northern Borefield that were sampled for stygofauna are P26, P31, P32, P50, P54 and P60. Stygofauna habitat within the Northern Borefield is probably limited to relatively small saturated zones of sand and fine gravel in the upper aquifer layer. Due to the aquitard clay layer separating the upper


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and target aquifers, and the considerable depth to the target aquifer, energy inflow to the target aquifer is probably very low and it is considered unlikely that stygofauna exist in the target aquifer. Test pumping and groundwater modelling suggest that, within the Northern Borefield, there will be minimal drawdown of the upper aquifer because of the underlying clay layer (SRL 2018). Drawdown of the target aquifer will be up to 30 m in the centre of the borefield. In the absence of any recharge to offset water extraction, drawdown of the target aquifer will decrease to 2 m at approximately 7–8 km from the centre of the borefield. It is considered that potential stygofauna habitat exists only in the surficial detritals.

4. FIELD SURVEY Field survey for stygofauna was undertaken because of the relatively large number of species recorded in the broader area around Lake Disappointment, the presence of potential stygofauna habitat in the borefields, and the need to provide more certainty about stygofauna occurrence in the Project area.

4.1. Sampling Effort Survey for stygofauna occurred across rounds: October 2016, March 2017 and June 2017. Sampling was undertaken by Zootopia Environmental Services (rounds 1 and 2) and Bennelongia (round 3). Sampling effort is summarised in Table 2 and sampling site details are given as Appendix 2. Sampling sites are mapped in Figure 5. In total, 30 samples were collected from 15 bores. Four bores were within the Cory Borefield, six bores were within the Northern Borefield and five bores were in regional (reference) areas. All bores were uncovered except LDRC1602MB. The regional site Cumara Soak is an open soak approximately 3 m in diameter whose connection to groundwater is unknown. Table 2. Summary of sampling effort for stygofauna at Lake Disappointment.

Round Cory Borefield Northern Borefield Regional Total Net Pump Net Pump Net Pump

Round 1 2 4 2 8 Round 2 2 6 8 Round 3 2 1 6 2 3 14

Total 6 1 16 0 2 5 30

4.2. Methods

4.2.1. Field Methods Stygofauna sampling methods were based on Technical Guidance: Subterranean fauna survey (EPA 2016b), although varied slightly according to bore structure. Stygofauna were sampled using weighted plankton nets. Six hauls were taken at most sites, three with a 50 µm mesh net and three with a 150 µm mesh net. The net was lowered to the bottom of the hole, jerked up and down to agitate the benthos (increasing chances of collecting benthic species) and slowly retrieved. Nets were washed between holes to minimise cross-contamination. Where pumping equipment prevented net hauling, samples were collected by filtering pump outflow through a 50 µm haul net. The volume of water filtered varied (Appendix 1) according to the effectiveness of pumping infrastructure. For example, the motorised pump at Camp Bore allowed a relatively large volume of water to be filtered compared with other sites, which had to be manually pumped. Previous work suggests that results from pumping and net hauling are likely to be similar (Eberhard et al. 2009; Hancock et al. 2009). Cumara Soak was sampled by dragging a stygofauna net horizontally through the water column. All samples were preserved in 100% ethanol and refrigerated. In round 3, in situ water quality parameters [temperature, electrical conductance (EC) and pH] were measured at each site with a TPS WP-81 field meter. For bores where equipment could be deployed (i.e. holes where net haul sampling was possible), static water level (SWL) and hole depth were also measured using a water level meter. Water quality, SWL and hole depth were not measured in rounds 1 and 2.


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4.2.2. Laboratory Methods Samples from rounds 1 and 2 were processed by Alacran Environmental Science; those from round 3 were processed by Bennelongia and specimens from all three rounds of sampling were identified by Bennelongia. Samples processed by Bennelongia were elutriated to separate out heavy sediment particles and sieved into size fractions using 250, 90 and 53 µm screens, which were sorted under a dissecting microscope. Stygofauna specimens were identified to species, where possible, using available taxonomic literature and in-house expertise. Identification mostly required dissection and then examination of animal parts under a differential interference contrast compound microscope. If stygofauna did not represent a described species, they were assigned a species/morphospecies code.

4.3. Personnel Samples in round 1 and 2 were collected by Greg Harewood and sorted by Erich Volschenk. and round 3 samples were collected by Michael Curran and sorted by Jim Cocking, Mike Scanlon and Heather McLetchie. Specimens were identified by Jane McRae, Mike Scanlon (oligochaetes) and Stuart Halse (ostracods). Maps were compiled by Mike Scanlon, Michael Curran and Anton Mittra. Reporting was done by Anton Mittra.

5. RESULTS A total of 300 specimens belonging to at least 13 species of stygofauna were recorded in the three sampling events, with 198 specimens from nine species recorded in Rounds 1 and 2 and 102 specimens from eight species recorded in Round 3 (Table 3). Exemplar specimens are shown in Plate 1. Some specimens could not be identified to species level and were removed from the final list to avoid artificial inflation. A full list of recorded taxa including higher-order identifications is given in Appendix 3. Major groups recorded were oligochaetes, amphipods, syncarids, cyclopoid and harpacticoid copepods, and ostracods. Additionally, a rotifer and seven nematode specimens were recorded, although the extent of reliance of these species on stygal habitats is uncertain (the rotifer is a widespread species that has been recorded from surface water). One troglofaunal species, the dipluran Projapygidae sp. B20, was recorded as a singleton at LDRC1601 in Round 3. This specimen is not considered likely to indicate the presence of a significant troglofauna assemblage.

5.1. Sampling Efficiency Across the three sampling events, 16 out of 30 samples and 13 out of 15 sites yielded stygofauna. This included White Gum Bore, a regional bore approximately 15 km east of the proposed Northern Borefield, which only yielded nematodes and Cumara Soak, a regional bore located approximately 50 km east-northeast of the proposed Cory borefield, which yielded only the cyclopoid copepod Mesocyclops brooksi and the rotifer Eosphora ehrenbergii. Both Mesocyclops brooksi and Eosphora ehrenbergii are widespread and have been recorded commonly in surface water. Thus, the species recorded in regional bores White Gum Bore and Cumara Soak are of limited significance in the context of stygofauna. Bores P31 and P50 in the Northern Borefield did not yield stygofauna. Average number of specimens collected per sample (mean ± SE) was greater for pump samples (17.67 ± 10.28) than for net samples (8.08 ± 3.47), although this is probably an artefact of pump samples having been taken in only regional areas and the Cory Borefield, where yields of stygofauna were higher than the Northern Borefield. Average abundances per sample were 16.43 ± 8.74 in regional bores and 19.14 ± 10.37 in the Cory Borefield, as opposed to just 3.19 ± 1.94 in the Northern Borefield. It is not considered likely that sampling methods (pump vs. net) significantly affected yields. Sites with the highest number of recorded species were LDRC1602 (Cory Borefield) and Georgia Bore (regional), which both had four species. Average richness per site was 2.0 at both regional sites and within the Cory Borefield and 1.0 in the Northern Borefield.


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Table 3. Stygofauna species recorded at Lake Disappointment (including regional bores) from 2016 to 2017. Values shown are abundance (number of sites). Higher Classification Lowest Identification Round 1-2 Round 3 Total Comments on Distribution

Nematoda Nematoda sp. 7 (1) 7 (1) Not assessed in EIA. Rotifera

Eurotatoria Monogononta

Ploima Notommatidae Eosphora ehrenbergii 1 (1) 1 (1) Widespread species also known from surface water1; not assessed in EIA.

Annelida Clitellata

Enchytraeida

Enchytraeidae Enchytraeidae sp. B18 (LD) 17 (3) 17 (3) Potentially new species recorded from three sites in and around the Northern borefield.

Enchytraeidae sp. B19 (LD) 3 (1) 3 (1) Potentially new species recorded from one site in the Northern borefield. Haplotaxida

Tubificidae Tubificidae sp. B03 (LD) 1 (1) 3 (1) 4 (2) Potentially new species recorded from one site in the Northern borefield and at Georgia Bore (known linear range ca. 16 km).

Arthropoda Crustacea

Malacostraca Amphipoda

Paramelitidae nr Pilbarus sp. B07 47 (2) 18 (2) 65 (3) Potentially new species recorded from three regional sites (known linear range ca. 32 km).

Syncarida Parabathynellidae Atopobathynella sp. B27 1 (1) 1 (1) 2 (2) Potentially new species recorded from two sites in the Cory borefield.

Maxillopoda Cyclopoida

Cyclopidae Mesocyclops brooksi 2 (1) 2 (1) Widespread across southern Australia2. Orbuscyclops westaustraliensis 3 (1) 3 (1) Widespread throughout Australia3

Pilbaracyclops frustratio 102 (2) 46 (3) 148 (4) Widespread across the Pilbara3, 4. Pilbaracyclops sp. B03 (nr frustratio) 26 (1) 26 (1) Widespread across the Pilbara3, 4.

Harpacticoida Parastenocarididae Dussartstenocaris sp. B08 12 (1) 12 (1) Potentially new species recorded from one site in the Cory borefield.

Ostracoda Popocopida

Cyprididae Cypridopsis sp. BOS920 1 (1) 1 (1) Widespread across the Pilbara. Also known from Andy Well, 500 km southwest of Lake Disappointment.

Total Richness 9 8 13 1ABRS 2009; 2Holynska 2003; 3Karanovic 2006; 4Bennelongia unpublished data.


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Plate 1. Exemplar stygofauna specimens collected from Lake Disappointment and regional bores. A) Tubificidae sp. B03 (LD); B) Cypridopsis sp. BOS920; C). nr. Pilbarus sp. B07; D) Pilbaracyclops frustratio; and E) Atopobathynella sp. B27. All four bores in the Cory Borefield yielded stygofauna, with samples containing between one and 68 specimens and one to four species. (The lowest yielding site within this area, Camp Bore, was only sampled in round 3; Appendix 2.) In contrast, two of six bores in the Northern Borefield failed to yield (P31 and P50), while the other four bores in this area produced between three and 31 specimens and one or two species. While it is noted that comparisons of yields should take into account variation in sampling effort at each site (Section 4.2.1), the higher proportion of non-yielding bores in the Northern Borefield is consistent with inferences based on average and absolute yields. It appears that the Cory Borefield hosts a richer and more abundant community than the Northern Borefield. It is also likely that the assemblages in each borefield are distinct from one another, with only one species, Pilbaracyclops frustratio, which is widespread outside the survey area, recorded in both borefields. The presence of distinct assemblages is consistent with the low level of hydraulic connectivity between the proposed borefields as inferred from test pumping (Section 3.2.2).


13

5.2. Species Distributions The collection locations of the different stygofauna species are shown in Figure 6. Nematoda sp. Nematode roundworms are ubiquitous and are commonly collected from groundwater habitats in stygofauna samples, although the taxonomy and ecology of species is largely undefined. Nematodes are therefore not typically assessed in stygofauna impact assessments. At Lake Disappointment, nematodes were recorded at White Gum Bore, a regional bore located approximately 70 km west-northwest of the proposed Northern borefield. Eosphora ehrenbergii This rotifer is widespread, having also been collected in surface water in the Pilbara and in eastern Australia (ABRS 2009; Pinder et al. 2010). Rotifers are not typically considered during stygofauna impact assessments and this species, which is regarded as primarily a surface species, is not of conservation concern. Oligochaetes Three species of oligochaete have been recorded at Lake Disappointment. Enchytraeidae sp. B18 (LD) was recorded in low to moderate abundance at holes P26 and P60 in the Northern Borefield and P32 just outside the Northern Borefield (Figure 6), resulting in an inferred minimum linear range of approximately 3 km, although this is likely to be a substantial underestimation of the actual species range. Similarly, Enchytraeidae sp. B19 (LD) was recorded in low abundance at a single site (P54) in the Northern Borefield (Figure 6) but is considered likely to occur more widely. Potential s tygofauna habitat in the Northern Borefield consists of the upper aquifer in surficial alluvial and colluvial deposits, which likely extends beyond the proposed borefield in association with McKay Creek (Figure 4). While there is some genetic information from assessment reports that can be interpreted as suggesting enchtraeids have small ranges, stygofaunal oligochaetes in general, including enchytraeids, tend to have catchment-scale distributions (i.e. tens to hundreds of kilometres in the Pilbara and, by analogy, elsewhere; see Brown et al. 2015). Considering the likely connectivity of the habitat north of Lake Disappointment, particularly detritals that comprise stygofauna habitat in the Northern Borefield and also occur in regional areas, it is considered likely that Enchytraeidae sp. B19 (LD) will be moderately widespread. The third oligochaete species, Tubificidae sp. B03 (LD), was recorded at P60 in the Northern Borefield and at Georgia Bore, a regional bore located approximately 15 km east of the proposed Northern Borefield (Figure 6). These sites are inside and outside the proposed borefield area, respectively, and their separation suggests a minimum linear range of about 15 km. Again, due to habitat continuity, this is likely to underestimate the species’ actual distribution. The collection locations of this species suggest habitat continuity between the Northern Borefield and wider regional areas. The relatively large linear range of Tubificidae sp. B03 (LD) and inferred habitat connectivity further suggest that both enchytraeid species are also likely to be widespread. nr Pilbarus sp. B07 This amphipod of the family Paramelitidae is locally widespread, having been recorded from the regional sites CRA Airstrip Bore, Georgia Bore and Lizard Bore, resulting in an inferred minimum linear range of more than 34 km. These collection sites are between eight and 20 km outside the proposed Northern Borefield (Figure 5) and are unlikely to be significantly impacted by drawdown (Section 6). Whether the widespread distribution of nr Pilbarus sp. B07 indicates historical or current habitat connectivity in areas surrounding the proposed Northern borefield is unclear.


15

Elsewhere in the Pilbara, increasing aridity is suggested to have led to population fragmentation (and subsequent speciation) within paramelitid lineages, with connectivity between aquifers lost due to the lowering of the water table (Finston et al. 2007). While amphipod species in the Pilbara are typically restricted to single sub-regions, with a median distribution of three sub-catchments (Halse et al. 2014), species of Pilbarus for which there are more than two records have mean linear ranges of approximately 120 km (Bennelongia unpublished data), although species that occur in calcretes are likely to be more tightly restricted. The distribution of nr Pilbarus sp. B07 is almost certainly underestimated and could be interpreted as suggesting that other stygofauna species in the area may also be more widespread than records indicate. Indeterminate fragments of a paramelitid amphipod, shown as Paramelitidae sp. in Figure 6, were recorded in the Cory Borefield (Appendix 3). It is not possible to determine whether these fragments belong to nr Pilbarus sp. B07 based on morphology or DNA analysis (tissue degeneration had occurred). Atopobathynella sp. B27 Single specimens of this syncarid species were recorded at both Camp Bore and LDCR1602 (Figure 6), resulting in an inferred minimum linear range of approximately 0.5 km. Considering the apparent extent and connectivity of aquifers within the Gunanya Sandstone, as well as the wider ranges of some other species in proposed borefields (e.g. nr Pilbarus sp. B07), this probably underestimates the species’ actual range. Cyclopoid copepods Four species of cyclopoid copepod were recorded during field survey. Mesocyclops brooksi was recorded in low abundance at Cumara Soak, a regional site approximately 50 km east-northeast of the proposed Northern borefield (Figure 6). This very common species has been recorded across southern Australia in both subterranean and surface water habitats (Holynska et al. 2003) and is not of conservation significance in the context of the Project. Orbuscyclops westaustraliensis was recorded in low abundance at Georgia Bore (Figure 6). This species has been recorded from subterranean samples across the Pilbara region but appears to be one of the few stygobitic, rather than stygophilic, cyclopoid species in Australia (Karanovic 2006). Given its wide distribution across the region, this species is not of conservation significance in the context of the Project. Pilbaracyclops frustratio was recorded in low to high abundance at LDRC1601, LDRC1602, LDRC1602 MB and P26 (Figure 6). This species has been recorded throughout the central and eastern Pilbara (Karanovic 2006; Bennelongia unpublished data) and is not of conservation significance in the context of the Project. It is the only species to be recorded in both the proposed Cory borefield and the proposed Northern borefield, although given its large distribution across the Pilbara, its occurrence in both areas is not considered to be a reflection of habitat connectivity between the proposed borefields. A fourth cyclopoid species, Pilbaracyclops sp. B03 (nr frustratio), was recorded outside the proposed borefields at CRA Airstrip Bore (Figure 6) where it was relatively abundant. This species differs from Pilbaracyclops frustratio by lacking an inner seta on the first exopod of pleopods 2 and 3. Pilbaracyclops sp. B03 (nr frustratio) is widespread through the central Pilbara. Dussartstenocaris sp. B08 This harpacticoid copepod was recorded in moderate abundance at LDRC1601 at Corey Borefield, while a single congeneric female specimen (Dussartstenocaris sp.) was recorded also in the Corey Borefield at LDRC1602 (Figure 6). Male specimens are normally required to identify members of Parastenocarididae to species-level using morphology, so it was not possible to determine whether


16

specimens from the two bores were conspecific (although it is considered highly likely). Many of the stygal harpacticoid species that have been reported as widespread have been shown, after DNA analysis, to comprise species complexes, with each species having a relatively small range (Karanovic and McRae 2013). It is considered probable, however, that Dussartstenocaris sp. B08 occurs more widely throughout the Gunanya Sandstone and possibly throughout the Lake Disappointment area due to the likely extent and connectivity of habitat surrounding the proposed Cory borefield (Figure 2). Cypridopsis sp. BOS920 This ostracod of the family Cyprididae was recorded as a singleton at Georgia Bore, where several indeterminate damaged congeneric specimens were also recorded on different sampling occasions. These indeterminate specimens are considered to belong to Cypridopsis sp. BOS920 because of the relatively rare occurrence of subterranean Cypridopsis in Western Australia. Cypridopsis sp. BOS920 is not considered to be of conservation significance in the context of the Project because it has also been recorded by Bennelongia approximately 300 km southwest of Lake Disappointment.

5.3. Stygofauna Values In overview, the stygofauna community at Lake Disappointment does not appear to be notably speciose. Results from the two proposed borefields suggest that the Cory Borefield (and possibly the wider Gunanya Sandstone) contains a modest stygofauna community, while the Northern Borefield is less rich. Sampling at the limited number of regional sites that were available also produced low to moderate yields. Sampling of regional calcretes may show that richer communities occur in the wider landscape, though such calcretes will be unaffected by dewatering. While a considerable proportion of recorded species are known to be widespread and have been recorded elsewhere in the Pilbara, neighbouring regions or across the continent, some specimens appear to belong to new species that have not been recorded outside the Lake Disappoint area. Three of these species are crustaceans and belong to groups with adequate taxonomic frameworks for the recognition of species: the paramelitid amphipod nr. Pilbarus sp. B07; the syncarid Atopobathynella sp. B27; and the harpacticoid copepod Dussartstenocaris sp. B08. The other three species are oligochaetes [Enchytraeidae sp. B18 (LD), Enchytraeidae sp. B19 (LD) and Tubificidae sp. B03 (LD)] that, particularly in the case of the enchytraeids, belong to groups with relatively poorly developed frameworks for recognising species in a consistent way. Based on available hydrogeological information, it is considered likely that all six new species have at least locally extensive ranges around Lake Disappointment. In the cases of Tubificidae sp. B03 (LD) and nr Pilbarus sp. B07, sampling has already demonstrated locally extensive ranges. The habitat connectivity that supports the extensive occurrence of these species is also likely to support locally widespread occurrences of the other four species.

6. POTENTIAL IMPACTS ON STYGOFAUNA The primary factor that could potentially threaten the persistence of any restricted stygofauna species at the Project is the abstraction of groundwater. Depending on the amount of drawdown, the depth of the aquifer and component of the aquifer occupied by the species, abstraction has the potential to significantly reduce the habitat available to such species. Four species are known only from locations inside the proposed borefields and/or inside the areas of drawdown predicted by hydrogeological modelling (SRK 2018). These species are Atopobathynella sp. B27 and Dussartstenocaris sp. B08 in the Cory Borefield (Figure 7) and Enchytraeidae sp. B18 (LD) and Enchytraeidae sp. B19 in the Northern Borefield (Figure 8).


19

The actual distributions of both Atopobathynella sp. B27 and Dussartstenocaris sp. B08 are considered to be greater than shown by field survey because of (a) the likely connectivity of available stygofauna habitat throughout the Gunanya Sandstone (Section 3.2.1), and (b) the locally extensive ranges of other stygofauna species recorded during survey. Sampling effort was relatively low owing to the limited availability of bores throughout the study area. Increased sampling over a larger area, particularly to the northwest of the Cory Borefield in the Gunanya Sandstone aquifer and potentially to the southwest in calcrete and paleovally deposits, is likely result in range extensions for these species beyond the influence of predicted drawdown. Similarly, the two enchytraeid species (Enchytraeidae sp. B18 (LD) and Enchytraeidae sp. B19) known only from in and around the Northern Borefield are probably more widespread than collections show. The connectivity of suitable habitat outside the Northern Borefield has been demonstrated by both hydrogeology and the ranges of other species. Further sampling would be likely to increase known ranges for these species. The occurrence of another oligochaete, Tubificidae sp. B03 (LD) both inside the Northern Borefield [including the same collection location as Enchytraeidae sp. B18 (LD)] and 15 km to the east at Georgia Bore shows the potential for larger ranges of both enchytraeid species. Regardless of species ranges, information in the borefield assessment suggests that minimal drawdown of primary stygofauna habitat will occur in the upper aquifer and therefore the level of impact of groundwater abstraction on stygofauna is likely to be low. In addition to the likely wider occurrence of the species known only from the two borefields, the extent of drawdown in Cory Borefield will be small in relation to the 100 m or so thickness of fractured Gunanya Sandstone that offers habitat for stygofauna, with drawdown in most of the borefield being less than 4 m (see SRK 2018). The extent of drawdown that might affect stygofauna was modelled as 2 m (Figure 7), although the homogeneity of the aquifer suggests much greater drawdown is likely to be tolerated. The extent of drawdown in the Northern Borefield is more significant, given there is likely to be only a thin band of moisture supporting stygofauna. The extent of drawdown that might affect stygofauna was modelled as 5 m and it is likely that no stygofauna habitat at all will remain within this modelled zone of drawdown. However, as already explained, this borefield supports a depauperate fauna of species that are likely to be locally widespread. It is although worth noting that numerical modelling of drawdown for both borefields assumed a project duration of 30 years and no groundwater recharge throughout the operation phase.

7. CONCLUSIONS This report aims to characterise stygofauna habitat and communities in the vicinity of the Project, determine the distributions of species and assess the likelihood that the Project would threaten stygofauna species. The main potential stygofauna habitats in the vicinity of the Project are aquifers in the Gunanya Sandstone that will be targeted by the proposed Cory Borefield and upper aquifers in surficial alluvial and colluvial deposits in the Northern Borefield. Test pumping suggests that aquifers in the Gunanya Sandstone, where the Cory Borefield is proposed, are well connected regionally and, by inference, stygofauna habitat probably occurs throughout this sandstone. The Northern Borefield will abstract from relatively deep aquifers that are regarded as being separated from the upper aquifers (potential stygofauna habitat) by a confining clay layer. Due to depth and the confining clay layer it is unlikely that stygofauna occur in the target aquifer. Field survey showed the proposed borefields and surrounding areas to host a modest stygofauna community of 13 species, seven of which are known to be widespread (i.e. they have been recorded outside the study area) and the remaining six known only from the Lake Disappointment area. Two of


20

these species – nr Pilbarus sp. B07 and Tubificidae sp. B03 – were collected from outside the expected extent of groundwater drawdown associated with the borefields. Four species are known only from inside proposed borefields and/or areas of predicted drawdown – Atopobathynella sp. B27, Dussartstenocaris sp. B08, Enchytraeidae sp. B18 (LD) and Enchytraeidae sp. B19 (LD). Due to the extent and connectivity of habitat and the wider distributions of other species in the area, it is considered unlikely that any of the four species is confined to collection locations in the proposed borefields or to areas inside predicted drawdowns.

8. REFERENCES ABRS (2009) Australian Faunal Directory. Australian Biological Resources Study, Canberra.

http://www.environment.gov.au/biodiversity/abrs/online-resources/fauna/afd/index.html Achurra, A., Rodriguez, P., and Reynoldson, T.B. (2015) Is the Cantabrian region of northern Spain a

biodiversity hotspot for obligate groundwater fauna? The case of oligochaetes (Annelida, Clitellata). Hydrobiologia 745, 151-166.

Bennelongia (2012) Subterranean fauna assessment of the Kintyre Uranium deposit. Report 2012/147. Bennelongia Pty Ltd, Jolimont, 37 pp.

Bennelongia (2013) Stygofauna Monitoring: Telfer Gold Mine, October 2012. Report 2013/192. Bennelongia Pty Ltd, Jolimont, 31 pp.

Bennelongia (2016) Lake Disappointment Subterranean Fauna Desktop Assessment. Report 269/2016. Bennelongia Pty Ltd, Jolimont, 19 pp.

Bennelongia (2017) Yangibana Rare Earth Project: Subterranean Fauna Assessment. Report 293/2017. Bennelongia Pty Ltd, Jolimont, 39 pp.

Brown, L., T. Finston, G. Humphreys, S. Eberhard, A. Pinder. (2015) Goundwater oligochaetes show complex genetic patterns of distribution in the Pilbara region of Western Australia. Invertebrate Systematics 29, 405-420.

Eberhard, S.M., Halse, S.A. and Humphreys, W.F. (2005) Stygofauna in the Pilbara region, north-west Western Australia: a review. Journal of the Royal Society of Western Australia, 88, 167-176.

Eberhard, S.M., Halse, S.A., Williams, M.R., Scanlon, M.D., Cocking, J., and Barron, H.J. (2009) Exploring the relationship between sampling efficiency and short-range endemism for groundwater fauna in the Pilbara region, Western Australia. Freshwater Biology 54, 885–901.

ecologia Environment (2009) Tropicana Gold Project - Stygofauna Survey Report. ecologia Environment, West Perth, 40 pp.

EPA (2016a) Environmental Factor Guideline: Subterranean fauna. EPA, Western Australia. EPA (2016b) Technical Guidance: Subterranean fauna survey. EPA, Western Australia. Finston, T.L., Johnson, M.S., Humphreys, W.F., Eberhard, S.M., and Halse, S.A. (2007) Cryptic speciation

in two widespread subterranean amphipod genera reflects historical drainage patterns in an ancient landscape. Molecular Ecology 16, 355-365.

GHD (2009) Report for Jack Hills expansion project regional stygofauna phase 1 survey. GHD, Perth. Gibert, J., and Deharveng, L. (2002) Subterranean ecosystems: a truncated functional biodiversity. .

BioScience 52, 473-481. GSWA (2012) 1:250 000 Digital Data Package – Regolith and ASTER maps of Western Australia 2012.

Geological Survey of Western Australia, CSRIO, Perth. Halse, S.A., Scanlon, M.D., Cocking, J.S., Barron, H.J., Richardson, J.B., and Eberhard, S.M. (2014) Pilbara

stygofauna: deep groundwater of an arid landscape contains globally significant radiation of biodiversity. Records of the Western Australian Museum Supplement 78, 443-483.

Hancock, P., Hunt, R., and Boulton, A. (2009) Preface: hydrogeoecology, the interdisciplinary study of groundwater dependent ecosystems. Hydrogeology Journal 17, 1-3.

Holynska, M., Mirabdullayev, I.M., Reid, J.W., and Ueda, H. (Eds) (2003) 'Copepoda: Cyclopoida. Genera Mesocyclops and Thermocyclops.' Guides to the identification of the microinvertebrates of the continental waters of the world (Backhuys: Leiden)

http://www.environment.gov.au/biodiversity/abrs/online-resources/fauna/afd/home


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Hose, G.C., J. Sreekanth, O. Barron and C. Pollino (2015) Stygofauna in Australian Groundwater Systems: Extent of knowledge. CSIRO, Australia.

Humphreys, W. (2009) Hydrogeology and groundwater ecology: Does each inform the other? Hydrogeology Journal 17, 5-21.

Humphreys, W.F. (2001) Groundwater calcrete aquifers in the Australian arid zone: the context to an unfolding plethora of stygal biodiversity. Records of the Western Australian Museum Supplement 64, 63-83.

Karanovic, T. (2004) Subterranean copepods (Crustacea: Copepoda) from arid Western Australia. Crustaceana Supplement 3, 1-366.

Karanovic, T. (2006) Subterranean copepods (Crustacea, Copepoda) from the Pilbara region in Western Australia. Records of the Western Australian Museum Supplement 70, 1-239.

Karanovic, T., and McRae, J. (2013) The genus Schizopera (Copepoda, Harpacticoida) in the Pilbara region of Western Australia, with description of a new species and its molecular and morphological affinities. Records of the Western Australian Museum 119, 28.

Korbel, K., and Hose, G. (2011) A tiered framework for assessing groundwater ecosystem health. Hydrobiologia 661, 329-349.

Phoenix (2009) Davidson Creek Iron Ore Project Short-range Endemic Invertebrate Fauna Survey. Draft Report. Phoenix Environmental Science, Northbridge, WA, 37 pp.

Pinder, A.M., Eberhard, S.M., and Humphreys, W.F. (2006) New phallodrilines (Annelida: Clitellata: Tubificidae) from Western Australian groundwater. Zootaxa 1304, 31–48.

Pinder, A.M., Halse, S.A., Shiel, R.J., and McRae, J.M. (2010) An arid zone awash with diversity: patterns in the distribution of aquatic invertebrates in the Pilbara region of Western Australia. Records of the Western Australian Museum Supplement 78, 205-246.

SRK (2018) Project Memo: Lake Disappointment groundwater review, 28 September 2018. SRK Consulting, West Perth.

Strategic Water Management (2018) Hydrogeological assessment of the Impact of Process Water Abstraction from the Cory Bore Field. An H2 Level Assessment for 2 GL/year. Unpublished technical report to Reward Minerals Ltd, June 2018.


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9. APPENDICES Appendix 1. Stygofauna species previously recorded in the vicinity of the Project identified through desktop review.

Higher Classification

Lowest Identification Kintyre1 Telfer2 Davidson

Creek3 Eastern Pilbara4

Carnegie5

Nematoda Nematoda sp. x x x Rotifera Bdelloidea sp.* x Bdelloidea sp. 3:2 x Dissotrocha sp.* x Filinia sp. x Mollusca

Gastropoda Hydrobiidae sp. B02 x Annelida

Aphanoneura Aeolosoma sp. 1 (PSS) x Aeolosoma sp. 2 (PSS) x Polychaeta Namanereis sp. B01 x Namanereis pilbarensis x Clitellata

Oligochaeta Oligochaeta sp.* x Pristina aequiseta x x Pristina longiseta x x Enchytraeidae sp.* x x x Enchytraeidae sp. 3 (PSW) Pilbara x Enchytraeus sp. 1 (PSS) Pilbara x Enchytraeus sp. 2 (PSS) Pilbara x Insulodrilus sp. x Phreodrilid with dissimilar ventral chaetae x x x Phreodrilid with similar ventral chaetae x x Tubificidae sp. stygo morphotype 2 (PSS) x

Tubificidae sp. stygo type 1 (imm Ainudrilus ?WA25/26) (PSS)

x

Tubificidae sp. stygo type 4 x

Tubificidae stygo type 1 (imm. Ainudrilus WA25/26?) (PSS)

x

Tubificidae stygo type 5 x Tubificoid Naididae stygo type 5 x Arthropoda

Crustacea Ostracoda ?Candoninae sp.* x

Areacandona iuno x Areacandona scanlonii x Candonopsis `tuccamunna ̀ x Candonopsis cf. tenuis x Candonopsis dedeckkeri x Humphreyscandona `yandagoogeae ̀ x Leicacandona jula x Leicacandona n. sp. (IK) x Leicacandona pinkajartinyi x Leicacandona quasihalsei x Cypretta seurati x x Cyprinotus kimberleyensis x Sarscypridopsis ochracea x Stenocypris bolieki x Gomphodella sp. BOS354 x Darwinulidae sp. x

Maxillopoda Copepoda

Calanoida Eudiaptomus lumholtzi x Cyclopoida ‘Bryocyclops’ sp. 1 (PSS) x

Diacyclops cockingi x x Diacyclops humphreysi humphreysi x x x Diacyclops scanloni x x Diacyclops sobeprolatus x Diacyclops sp.* x Fierscyclops (Fierscyclops) sp. B04 x Goniocyclops sp. B07 x Halicyclops calm x Halicyclops kieferi x Halicyclops sp. x Metacyclops sp.* x x


23

Higher Classification

Lowest Identification Kintyre1 Telfer2 Davidson

Creek3 Eastern Pilbara4

Carnegie5

Mesocyclops brooksi x Mesocyclops sp. x Microcyclops varicans x x x x Orbuscyclops westaustraliensis x Pescecyclops sp. B02 (nr kimberleyi) x Pilbaracyclops frustratio x x Cyclopoida sp.* x x

Harpacticoida Harpacticoida sp.* x

Harpacticoida sp. B01 x

Abnitocrella sp. 1 (TOK) x Abnitocrella sp. B02 (nr obesa)* x Megastygonitocrella bispinosa x Megastygonitocrella sp. B03 (nr ecowisei) x Megastygonitocrella unispinosa x Nitocrella sp. B03 (nr trajani)* x Nitocrella sp. B04 (nr obesa) x Nitocrella sp. B05 x Ameridae (nr Gordonnitocrella) sp. B01 x Australocamptus sp. B02 x Elaphoidella humphreysi x Canthocamptidae sp.* x x Parastenocaris sp.* x x Parastenocaris sp. B07 x x Parastenocaris sp. B09 x Parastenocaris sp. B10 x Parastenocaris sp. B11 x Parastenocaris sp. B12 x Parastenocaris sp. B20 x

Malacostraca Syncarida Atopobathynella sp. x x

nr Billibathynella (Brevisomabathynella) sp. B08 x Hexabathynella sp. A (PSS) x Notobathynella sp. B06 x Parabathynellidae sp. x

Amphipoda Bogidiellidae sp.* x Bogidiellidae sp. 1 (PSS) x Bogidiellidae sp. B02 x x Melitidae sp. x Chydaekata sp. x Molina cf. pleobranchos (PSS) x Paramelitidae sp. x Paramelitidae sp. 2 (PSS) x Paramelitidae sp. B06 x x Paramelitidae sp. B07 x x Paramelitidae sp. B10 x Paramelitidae sp. B11 x Paramelitidae sp. B28 x Paramelitidae sp. B30 x Pilbarus sp. x Pilbarus sp. S01 (PSS) x

Isopoda Microcerberidae sp.* x x Microcerberidae sp. B04 x Adoniscus sp. B01 x Pygolabis weeliwolli x

Hexapoda Insecta Insecta sp.* x

Diptera Tanypodinae sp. x Diptera sp.* x Coleoptera Limbodessus harleyi x

Total Richness 16 39 23 56 7 *Higher-order identifications not included in final estimate of richness. 1Bennelongia 2012; 2Bennelongia 2014; 3Phoenix 2009; 4Halse et al. 2014; 5DPaW unpublished data.


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Appendix 2. Details of holes sampled for stygofauna around Lake Disappointment between 2016 and 2017. All data for water levels, hole depth and water chemistry were recorded in Round 3 (June 2017).

Hole Round(s) Area Sample Method SWL (mbgl) End of Hole (m) Temperature (°C) EC (µS cm-1) pH Comments

White Gum Bore 3 Regional Net 9 14 27.3 105.5 5.07 Slotted

CRA Airstrip Bore 1, 3 Regional Pump 27.3 930 6.61 ~90 L filtered in Round 3

Lizard Bore 3 Regional Pump 28.9 970 6.79 ~150 L filtered in Round 3

P54 1, 2, 3 Northern Borefield Net 14 70 24.7 3370 6.78 Three hauls using two nets (⌀= 45 mm and 90 mm) simultaneously

P60 2, 3 Northern Borefield Net 13 95 25.4 1439 6.83 Four hauls using two nets (⌀= 45 mm and 90 mm) simultaneously

P50 1, 2, 3 Northern Borefield Net 13 120 22.9 1598 7.08 Four hauls using two nets (⌀= 45 mm and 90 mm) simultaneously

P31 1, 2, 3 Northern Borefield Net 13 100 1184 7.06

P32 1, 2, 3 Northern Borefield Net 10 43 1055 7.28

P26 2, 3 Northern Borefield Net 10 96 21 310 6.02

Georgia Bore 1, 3 Regional Pump 21.5 1051 7.37 ~310 L filtered in Round 3

Cumara Soak 3 Regional Net 17.9 2340 6.4 Open soak, ⌀~ 3 m; three horizontal hauls with 50 µm net.

LDRC1601 1, 2 Cory Borefield Net

LDRC1602 1, 2, 3 Cory Borefield Net 9 90 25.2 325 7.05

LDRC1602 MB 3 Cory Borefield Net 9 108 25.4 4510 6.6 Two hauls with haul nets (⌀= 45 mm)

Camp Bore 3 Cory Borefield Pump (motorised) 25.5 4780 7.18 Pumped for 20 min (~600 L)


25

Appendix 3. Stygofauna species recorded at Lake Disappointment from October 2016 to March 2017, including collection locations of each species. Regional Cory Borefield Northern Borefield

Higher Classification Lowest Identification

CRA

Airs

trip

Bo

re

Cum

ara

Soak

Geo

rgia

Bor

e

Liza

rd B

ore

Whi

te G

um

Bore

LDRC

1601

LDRC

1602

LDRC

1602

MB

Cam

p Bo

re

P26

P32

P54

P60

Round 1-2 Annelida

Clitellata Enchytraeida

Enchytraeidae Enchytraeidae sp. B18 (LD) 1 11 5 Enchytraeidae sp. B19 (LD) 3

Haplotaxida Tubificidae Tubificidae sp. B03 (LD) 1

Arthropoda Crustacea

Malacostraca Amphipoda

Paramelitidae nr Pilbarus sp. B07 41 6 Paramelitidae sp.* 1

Syncarida Parabathynellidae Atopobathynella sp. B27 1


Cyclopidae Pilbaracyclops frustratio 51 51 Pilbaracyclops sp. B03 (nr frustratio) 26

Harpacticoida Parastenocarididae Dussartstenocaris sp.* 1

Dussartstenocaris sp. B08 12 Ostracoda

Popocopida Cyprididae Cypridopsis sp. BOS920 1

Round 1-2 Total 67 7 63 54 1 11 3 6

Round 3 Nematoda Nematoda sp. 7 Rotifera

Eurotatoria Monogononta

Ploima Notommatidae Eosphora ehrenbergii 1

Annelida


26

Regional Cory Borefield Northern Borefield

Higher Classification Lowest Identification

CRA

Airs

trip

Bo

re

Cum

ara

Soak

Geo

rgia

Bor

e

Liza

rd B

ore

Whi

te G

um

Bore

LDRC

1601

LDRC

1602

LDRC

1602

MB

Cam

p Bo

re

P26

P32

P54

P60

Clitellata Haplotaxida

Tubificidae Tubificidae sp. B03 (LD) 3 Arthropoda

Crustacea Malacostraca

Amphipoda Paramelitidae nr Pilbarus sp. B07 6 12

Syncarida Parabathynellidae Atopobathynella sp. B27

1


Cyclopidae Mesocyclops brooksi 2 Orbuscyclops westaustraliensis 3 Pilbaracyclops frustratio 14 2 30

Ostracoda Popocopida

Cyprididae Cypridopsis sp.* 7 Round 3 Total 3 19 12 7

14 2 1 30

Total abundance 67 3 26 12 7 63 68 2 1 31 11 3 6 Total richness 2 2 4 1 1 2 4 1 1 2 1 1 2 *Indicates higher-order identifications that were not included in final estimate of richness unless no other species from the same taxonomic unit was present.

Stygofauna Values at the Lake Disappointment Potash Project · 2019-02-01 · Stygofauna Values at...

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