THREATENED SPECIES SCIENTIFIC COMMITTEE Established under the Environment Protection and Biodiversity Conservation Act 1999

The Minister’s delegate approved this Conservation Advice on 16/12/2016

Conservation Advice pedderensis

Pedder galaxias

Conservation Status

Galaxias pedderensis () is listed as Extinct in the Wild under the Environment Protection and Biodiversity Conservation Act 1999 (Cwlth) (EPBC Act) effective from 7 July 2005. The Pedder galaxias was uplisted in 2005 in the EPBC Act threatened species list from the Endangered category to the Extinct in the Wild category. Before 2005, the species was eligible for listing under the EPBC Act as Endangered from 16 July 2000 as it was listed as Endangered under Schedule 1 of the preceding Act, the Endangered Species Protection Act 1992 (Cwlth).

Species can also be listed as threatened under state and territory legislation. For information on the current listing status of this species under relevant state or territory legislation, see http://www.environment.gov.au/cgi-bin/sprat/public/sprat.pl

The main factors that are the cause of the species being eligible for listing in the Extinct in the Wild category are that the information to date suggests that the Pedder galaxias is likely to be extinct in its natural habitat in (TSSC 2005). There are translocated populations at Strathgordon Dam and Lake Oberon, which are areas outside its natural historical range (TSSC 2005). Despite extensive surveying, the Pedder galaxias has not been recorded in Lake Pedder since 1996 (TSSC 2005). The species has no particular life-cycle characteristics which may explain why it remained undetected throughout surveys, and given that the species lives for around six years, it is considered unlikely that the species still exists in the area (TSSC 2005).

Description

The Pedder galaxias, family , is a small, slender freshwater , reaching a maximum length of approximately 170 mm (TSS 2006). Adults are light grey-brown in colour with irregular dark blotches and spots on the back and sides, tending to a whitish belly (McDowall & Frankenberg 1981; Fulton 1990; Allen et al., 2002; TSS 2006). Gold iridescence is often present on the back and sides, with a conspicuous gold patch on the operculum (Andrews 1976; TSS 2006). The irregular blotches and spots are also found on the head and extend up the fleshy bases of the dorsal, caudal and anal fins (Fulton 1990; Allen et al., 2002). The species is distinguished from other galaxiids by its slender body shape and slightly downwards facing mouth, given that the lower jaw is distinctly undercut (Allen et al., 2002; TSS 2006).

Distribution

The Pedder galaxias is endemic to southwestern , and naturally occurred only in Lake Pedder and inflowing streams and tributaries of the Serpentine River and Wedge River, and swampy pools near the lake (Frankenberg 1968; Andrews 1976). It shared this restricted range with another galaxiid, Galaxias parvus (swamp galaxias) (Frankenberg 1968; Andrews 1976). Lake Pedder was inundated and enlarged after the completion of Edgar Dam, Serpentine Dam Galaxias pedderensis (Pedder galaxias) Conservation Advice Page 1 of 6

and Dam in the early 1970s, and the Pedder galaxias was still considered to be abundant in the enlarged lake until 1980 (McDowall & Frankenberg 1981; TSS 2006). However, the species declined rapidly after 1980 (Lake 1998, cited in TSS 2006).

The initial colonisation by brown ( Salmo trutta ) of Lake Pedder was bolstered by a single stocking of 350 000 hatchery-raised brown trout fry in 1972 to provide a recreational fishery in the newly dammed water body (IFC 1973; Hamr 1992, both cited in Chilcott et al., 2013). The flooding of Lake Pedder and the introduction of alien fish species, which consequently led to competition and predation, appear highly likely to have had the significant detrimental impact which led to the extirpation of Pedder galaxias from its natural distribution (Chilcott et al., 2013). Since 1996, no survey has detected the species in Lake Pedder or its upstream tributaries, despite intensive annual electrofishing surveys between 1996 and 2002 (IFS unpubl. data, cited in Chilcott et al., 2013).

Between 1991 and 1997, 34 Pedder galaxias were released into Lake Oberon, a glacial cirque lake about 10 km south of the southernmost shore of the enlarged Lake Pedder (Chilcott et al., 2013). Situated at an altitude of 851 m in the Western Arthurs Range given that it was devoid of other fish species, had inflowing streams, food sources and suitable habitats for Pedder galaxias (Chilcott et al., 2013). Since then, numbers of Pedder galaxias in Lake Oberon have increased rapidly and further translocation of 353 individuals from Lake Oberon to Strathgordon Dam occurred between 2001 and 2007 (Chilcott et al., 2013). The Strathgordon Dam population is now considered well established (Chilcott et al., 2013).

The Pedder galaxias occurs within the Interim Biogeographic Regionalisation for (IBRA) Bioregion and the South Natural Resource Management Region.

The distribution of the Pedder galaxias is not known to overlap with any EPBC Act-listed threatened ecological community.

The Department of the Environment has prepared survey guidelines for the Pedder galaxias. The survey guidelines are intended to provide guidance for stakeholders on the effort and methods considered appropriate when conducting a presence/absence survey for species listed as threatened under the EPBC Act. http://www.environment.gov.au/epbc/publications/threatened-fish.html

Relevant Biology/Ecology

The Pedder galaxias is restricted to freshwater habitats, and is both a lacustrine (lake-dwelling) and stream-dwelling species (TSS 2006) preferring high altitudes. It is thought that the lacustrine environment of the original Lake Pedder served as a nursery habitat for pelagic larvae and juveniles, with adults requiring stream habitats for spawning (TSS 2006). The lacustrine preference of the species’ larvae may have made it vulnerable to trout predation (McDowall 2006). In comparison, the congeneric swamp galaxias does not have a lacustrine life stage and still persists in the enlarged Lake Pedder (McDowall 2006). The two locations where Pedder galaxias have now established are free from trout (family ) (TSS 2006; Chilcott et al., 2013).

The Pedder galaxias is an opportunistic carnivore and feeds on terrestrial and aquatic , including terrestrial , aquatic larvae, aquatic and (Hamr 1995; TSS 2006). It is considered that when adults of the species moved into the inflowing streams of Lake Pedder, it preferred the forested sections of stream with deep pools, relatively slow flow, sandy bottom and abundant cover (Hamr 1995). The species is an active

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mid-water swimmer and both adults and juveniles can be observed swimming mid-water in pools (TSS 2006).

The Pedder galaxias spawns in spring (October) when water temperatures begin to rise (Hamr 1995). Maturity is reached at two years of age and they live to at least six years (TSS 2006). Females produce between 200 - 1200 eggs (2.2 - 2.5 mm in diameter) which are deposited under flat rocks, aquatic vegetation or submerged driftwood (Hamr 1995). Eggs artificially fertilised in captivity after stripping took 22 - 30 days to hatch at 15 - 16°C (TSS 2006). Larvae are approximately 10 mm long on hatching (Hamr 1992, cited in TSS 2006).

Threats

Competition and predation by the alien fish species, brown trout ( Salmo trutta ), is the primary threat to the Pedder galaxias (TSS 2006). It is likely that the habitat loss also severely impacted the Pedder galaxias, caused by the inundation of Lake Pedder and its critical habitats after it was dammed (TSS 2006; Chilcott et al., 2013).

Table 1 – Threats impacting the Pedder galaxias in approximate order of severity of risk, based on available evidence.

Threat factor Threat Evidence base type and status

Invasive species

Competition known The introduction of brown trout ( Salmo trutta ) and subsequent and predation current establishment of the species in Lake Pedder are likely to have by alien fish significantly impacted on the Pedder galaxias. Anecdotal species reports indicate that trout preyed heavily upon the species in the late-1970s and the species was commonly used as live bait for trout (Terry 1994, cited in Chilcott et al., 2013).

A presence of trout in Lake Pedder prevents recolonisation of the Pedder galaxias into its original, natural habitat.

Up until 2013, Lake Oberon and Strathgordon Dam, where the two translocated populations of the Pedder galaxias exist, have had no trout introduced (Chilcott et al., 2013). However, there were recently two Galaxias brevipinnis () individuals detected at Strathgordon Dam (Chilcott et al., 2013). The climbing galaxias is the largest galaxiid species in Australia, and also occurs in , and is known to prey on smaller galaxias species (Allen et al., 2002). The climbing galaxias is thought to have displaced some of the non-migratory galaxiid species from selected New Zealand waterways (McDowall & Allibone 1994; Allibone 1999).

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Any attempt to reintroduce Pedder galaxias to Lake Pedder will need to monitor for any invasion of redfin perch (Perca fluviatilis ) into the lake from elsewhere, such as from the close by , which water from Lake Pedder drains into via the McPartlan Canal (Chilcott et al., 2013). Lake Gordon has an abundant, self-sustaining population of redfin perch. Redfin perch have been implicated in the decline of other galaxiid species (Crook & Sanger 1998; Hardie et al., 2006) and represent a potential threat to Pedder galaxias if they established in areas where the galaxiid occurs.

Habitat loss, disturbance and modifications

Loss of the suspected Before Lake Pedder was dammed and inundated, the original original past habitat in which the Pedder galaxias thrived was within a Lake Pedder relatively small lake (9 km 2 surface area) and the meandering habitat streams which flowed into the lake (TSS 2006). The original Lake Pedder was shallow, with maximum depths of approximately 3 m with an extensive pinkish white quartzitic sand beach on its eastern shoreline (Tyler et al., 1996, cited in Chilcott et al., 2013; Wilson et al., 2012). The post-dammed and inundated Lake Pedder had a surface area of 235 km 2 and a maximum depth of 43 m, with greatly different biophysical characteristics compared with the natural lake (Chilcott et al., 2013). Lacustrine galaxiids, such as the Pedder galaxias, rely on littoral zones to provide critical habitats and these zones would have been greatly disturbed by the inundation of Lake Pedder (Chilcott et al., 2013).

Conservation Actions

Conservation and management priorities

Invasive species

o Develop and implement a management plan designed to prevent the introduction of alien fish species to Lake Oberon and Strathgordon Dam that impact upon the Pedder galaxias, including trout (brown and rainbow) and redfin perch.

o Cease further stockings of salmonids into Lake Pedder.

Habitat loss disturbance and modifications

o Translocate individuals to a suitable water body that contains no other fish species.

o Create refuge zones for Pedder galaxias, free of brown trout and climbing galaxias, by installing a fish barrier across one of the tributary streams to Lake Pedder and exclude alien and fish not-native to the area.

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Stocking

o Establish a captive-breeding program for the Pedder galaxias to provide juveniles for conservation stocking over a sufficient time period.

Stakeholder Engagement

o Engage with recreational fishers about the importance of not-moving or translocating trout, and other alien fish species, around inland waters.

o If Pedder galaxias were to be reintroduced to the Lake Pedder system, increase compliance effort to ensure that the use of Pedder galaxias as live or dead bait for trout is strictly prohibited, noting that historically there was a strong preference of trout fishers for using the species as bait.

Survey and monitoring priorities

• Monitor the translocated species’ populations annually at the locations that the species is known to occur.

Information and research priorities

• Undertake a genetic study on the translocated populations to gather information on genetic diversity in the populations now that may inform future studies on the species’ genetic diversity. Non-lethal fins clips are probably most suitable.

References cited in the advice

Allen, G.R., Midgley, S.H., & Allen, M. (2002). Field Guide to the Freshwater of Australia . Western Australian Museum, Perth.

Allibone, R.M. (1999). Impoundment and introductions: Their impacts on native fish of the upper Waipori River, New Zealand. Journal of the Royal Society of New Zealand 29(4) , 291–299.

Andrews, A.P. (1976). A revision of the family Galaxiidae (Pisces) in Tasmania. Australian Journal of Marine and Freshwater Research 27 , 297 – 349.

Chilcott, S., Freeman, R., Davies, P.E., Crook, D.A., Fulton, W., Hamr, P., Jarvis, D., & Sanger, A.C. (2013). Extinct habitat, extant species: lessons learned from conservation recovery actions for the Pedder galaxias ( Galaxias pedderensis ) in south-west Tasmania, Australia. Marine and Freshwater Research 64 , 864 – 873.

Crook, D.A., & Sanger, A.C. (1998). Threatened fishes of the world: Galaxias johnstoni Scott, 1936 (Galaxiidae). Environmental Biology of Fishes 53 , 154.

Frankenberg, R. (1968). Two new species of Galaxiid fishes from the Lake Pedder region of southern Tasmania. Australian Zoologist 14(3) , 268 – 274.

Fulton, W. (1990). Tasmanian Freshwater Fishes . Fauna of Tasmania handbook no. 7, University of Tasmania, Hobart.

Hardie, S.A., Jackson, J.E., Barmuta, L.A., & White, R.W.G. (2006). Status of galaxiid fishes in Tasmania, Australia: conservation listings, threats and management issues. Aquatic conservation: Marine and Freshwater Ecosystems 16 , 235 – 250.

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Hamr, P. (1992). Conservation of Galaxias pedderensis. Report to the Endangered Species Unit, Australian National Parks and Wildlife Service. Inland Fisheries Commission, Occasional Report 92-01, Hobart, Tasmania.

Hamr, P. (1995). Threatened fishes of the world: Galaxias pedderensis Frankenberg, 1968 (Galaxiidae). Environmental Biology of Fishes 43 , 406.

Inland Fisheries Commission (IFC) (1973). Inland Fisheries Commission report for the year ending 30 June 1973 . Inland Fisheries Commission, Hobart, Tasmania.

Lake, P.S. (1998). After the inundation: long-term changes in the fauna of Lake Pedder, Tasmania, Australia. In: McComb, A.J. (ed.) (1998). Wetlands for the Future . Gleneagles Publishing, . pp. 565 – 578.

McDowall, R.M. (2006). Crying wolf, crying foul, or crying shame: alien salmonids and a biodiversity crisis in the southern cool-temperate galaxioid fishes?. Reviews in Fish Biology and Fisheries 16 , 233 – 422.

McDowall, R.M., & Allibone, R.M. (1994). Possible competitive exclusion of ( Galaxias vulgaris ) by koaro ( G. brevipinnis ) following impoundment of the Waipori River, Otago, New Zealand. Journal of the Royal Society of New Zealand 24(2) , 161–168.

McDowall, R.M., & Frankenberg, R.S. (1981). The galaxiid fishes of Australia (Pisces: Galaxiidae). Records of the Australian Museum 33(10) , 443 – 605.

Terry, N. (1994). The Great Trout of Lake Pedder . Artemis Publishing & Marketing Consultants: Hobart.

Threatened Species Section (TSS) (2006). Recovery Plan: Tasmanian Galaxiidae 2006–2010 . Tasmanian Department of Primary Industries and Water, Hobart, Tasmania.

Tyler, P.A., Sherwood, J.E., Magilton, C.J., & Hodgson, D.A. (1996). Limnological and geomorphological considerations underlying Pedder 2000 – the campaign to restore Lake Pedder. Archiv für Hydrobiologie 136 , 343 – 361.

Wilson, G.D.F., Osborn, A.W., & Forteath, G.N.R. (2012). Two new species of Colubotelson Nicholls, 1944 Tasmania’s Lake Pedder: persistence of Phreatoicidae (Crustacea, Isopoda) therein. Zootaxa 3406 , 1 – 29.

Other sources cited in the advice

Threatened Species Scientific Committee (TSSC) (2005). Commonwealth Listing Advice on Pedder galaxias ( Galaxias pedderensis ). Australian Government Department of Environment and Heritage, Canberra, Australian Capital Territory. Viewed: 26 February 2016 Available on the Internet at: http://www.environment.gov.au/cgi-bin/sprat/public/publicspecies.pl?taxon_id=26169

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