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 Galaxias johnstoni

Clarence galaxias

Conservation Status

Galaxias johnstoni (Clarence galaxias) is listed as Endangered under the Environment Protection and Biodiversity Conservation Act 1999 (Cwlth) (EPBC Act) effective from 16 July 2000. The species was eligible for listing under the EPBC Act as on 16 July 2000 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 make the species eligible for listing in the Endangered category are that the Clarence galaxias had experienced past decline, it had a limited distribution in central Tasmania that was severely fragmented and continuing decline was inferred given the presence of introduced fish species in areas where some of the populations occur (TSS 2006).

Description

The Clarence galaxias, family Galaxiidae, is a small, stout freshwater fish, reaching a maximum length of approximately 140 mm (Allen et al., 2002; TSS 2006). Adults are dark brown in colour with irregular brown bars or blotches on the back and sides, tending to a yellow belly (Allen et al., 2002; TSS 2006). Numerous very small black spots are often present, but these are parasites in the skin rather than natural markings of the species (Fulton 1990).

The Clarence galaxias is quite similar in appearance to Galaxias brevipinnis (climbing galaxias), which occurs in the same general area (TSS 2006). Features of the Clarence galaxias which distinguish it from the climbing galaxias are: a rounded blunt head with jaws of approximately equal length unlike the flat wedge-shaped head with the distinctly shorter lower jaw of the climbing galaxias; the yellowish colour of the belly; and the smaller pectoral fins rather than the large, rounded, low-set fins of climbing galaxias (TSS 2006).

Distribution

The Clarence galaxias is endemic to central Tasmania, and occurs only in isolated parts of the upper Derwent River catchment, including the Nive, Clarence and Little River catchments (TSS 2006). There are seven known populations, with the largest being found in Clarence Lagoon and Johnsons Lagoon (TSS 2006), just to the northeast of the settlement of Derwent Bridge.

The Clarence galaxias occurs within the Tasmanian Central Highlands Interim Biogeographic Regionalisation for Australia (IBRA) Bioregion and the South Natural Resource Management Region.

Galaxias johnstoni (Clarence galaxias) Conservation Advice Page 1 of 5

The distribution of the Clarence 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 Clarence 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 Clarence galaxias is restricted to freshwater habitats, and is both a lacustrine (lake- dwelling) and stream-dwelling species (Crook & Sanger 1998; TSS 2006) in high altitude areas of approximately 1000 m above sea level. The species appears to prefer the shelter of rocks and boulders in lacustrine habitats, and adults have been observed moving from lagoons into inlet streams to spawn in spring (Allen et al., 2002; McDowall 2006). Juveniles shoal together in mid-water (McDowall 2006). All locations where populations of the species occur are free of other fish species except for Clarence Lagoon where a population of brook trout (Salvelinus fontinalis ) is maintained (TSS 2006; IFS 2014). Fisheries managers consider brook trout a more benign alternative to brown trout (Salmo trutta ) (TSS 2006).

Populations are prevented from re-establishing in areas downstream from where they currently occur due to the presence of brown trout across the Derwent River catchment area (TSS 2006). Current populations are protected from invasion or establishment by brown trout by some form of barrier (e.g. a waterfall or fluctuating water levels) (TSS 2006).

Adult Clarence galaxias primarily feed on benthic crustaceans, and juveniles on planktonic crustaceans and terrestrial insects (Crook and Sanger 1998). The species inhabits deep pools, although spreads into other areas when water levels are high enough (TSS 2006).

The Clarence galaxias spawns in spring (Fulton 1990; Allen et al., 2002; TSS 2006). Egg masses of the Clarence galaxias have been found adhering to rocks in the lower reach of a stream flowing into a Wentworth Hills Lagoon (Fulton 1990), likely representing habitat typically used for spawning. Females lay between 300 - 2000 eggs which are large (~1.6 mm diameter) and strongly adhesive (Crook & Sanger 1998). Eggs in captivity incubate for between 42 and 52 days, hatching at water temperatures of 4 - 12°C (Jackson 2002, cited in TSS 2006).

Threats

Competition and predation by the alien fish species, brown trout ( Salmo trutta ) and rainbow trout (Oncorhynchus mykiss ), is the primary threat to the Clarence galaxias, if these species were introduced into its remaining habitat (TSS 2006). Other threats may include competition and predation by brook trout (Salvelinus fontinalis ) (TSS 2006).

Galaxias johnstoni (Clarence galaxias) Conservation Advice Page 2 of 5

Table 1 – Threats impacting the Clarence 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 Clarence galaxias is not known from any areas containing and predation current brown trout, and its disappearance from the Brown Marsh by alien fish Creek type locality, where brown trout are present, indicates species that it cannot survive where trout become established (TSS 2006). In 2004, heavy predation on Clarence galaxias by introduced rainbow trout (Oncorhynchus mykiss ) was observed in Johnsons Lagoon (TSS 2006). Fortunately, the rainbow trout were discovered before establishing a breeding population, and given that the lagoon is relatively shallow and small, an eradication was undertaken (Jackson et al., 2004). The single main known threat to the species is competition and predation by alien fish species (TSS 2006).

Competition uncertain The impact of brook trout on Clarence galaxias stocked into and predation Clarence Lagoon is reported as relatively benign in by the alien comparison to impacts predicted if brown or rainbow trout fish species – established in the lagoon (Crook & Sanger 1997, cited in brook trout Jackson et al., 2004; TSU 1998; TSS 2006). The brook trout population has been present in Clarence Lagoon since 1963 and is reportedly reproducing within Clarence Lagoon (Crook & Sanger 1997, cited in Jackson et al., 2004; IFS 2014). Between 1963 and 2004, the Clarence galaxias population remained in the lagoon despite the presence of brook trout during this time (Jackson et al., 2004). Recommendations made by the Inland Fisheries Commission on Tasmania’s trout stocking policy in 1991 argued the importance of stocking brook trout in Clarence Lagoon to deter illegal introductions of brown or rainbow trout which would likely extirpate the species from this location (Crook & Sanger 1997, cited in Jackson et al., 2004; TSU 1998). However, no dietary analysis research studies of brook trout in Clarence Lagoon have been undertaken.

Galaxias johnstoni (Clarence galaxias) Conservation Advice Page 3 of 5

Conservation Actions

Conservation and management priorities

Invasive species

o Develop and implement a management plan for alien fish species impacting Clarence galaxias, including trout (brown and rainbow) and redfin perch.

o To provide expansion and refuge areas downstream from where current populations are located (such as in the Clarence River), cease stocking of alien salmonids in locations restricting connectivity between fragmented populations, and consider options for placing trout barriers so that alien salmonids cannot access these areas.

Stakeholder Engagement

o As all fish are on reserved land protected under the National Parks and Reserves Management Act 2002 (Tas), engage with the relevant land managers that are responsible for the reserves and national parks where the Clarence galaxias is naturally occurring to promote the importance of managing invasive alien fish species, such as trout (brown and rainbow) and redfin perch.

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

o Increase compliance effort to ensure that the use of Clarence galaxias as live or dead bait for trout is strictly prohibited.

Survey and monitoring priorities

• Continue to monitor of the species’ population annually in the locations that the species is known to occur, and assess the effectiveness of management actions and the need to adapt them if necessary.

• Survey areas where the species previously occurred to determine whether there is any recovery.

Information and research priorities

• Investigate levels of predation on Clarence galaxias by the brook trout population in Clarence Lagoon.

• Undertake genetic studies to inform decisions on population protection, translocation and captive breeding, to ensure that genetic structure and diversity is maintained, given that all naturally occurring populations are isolated from each other.

References cited in the advice

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

Crook, D., & Sanger, A. (1997). Recovery plan for the Pedder, Swan, Clarence, swamp and saddled galaxias . Inland Fisheries Commission, Hobart, Tasmania.

Galaxias johnstoni (Clarence galaxias) Conservation Advice Page 4 of 5

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

Fulton W (1990). Tasmanian Freshwater Fishes . Fauna of Tasmania handbook no. 7, University of Tasmania, Hobart. Inland Fisheries Service (IFS) (2002). Western Lakes – Fishery Management Plan . November 2002, Inland Fisheries Service, Tasmanian Government, Hobart.

Jackson, J.E., Raadik, T.A., Lintermans, M., & Hammer, M. (2004). Alien salmonids in Australia: impediments to effective impact management, and future decisions. New Zealand Journal of Marine and Freshwater Research 38 , 447 – 455.

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.

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

Other sources cited in the advice

Inland Fisheries Service (IFS) (2014). Brook trout – Inland Fisheries Service – Managing trout fishing in Tasmania . Inland Fisheries Service, Tasmanian Government. Last modified: 19 January 2014. Viewed: 24 February 2016 Available on the Internet at: http://www.ifs.tas.gov.au/publications/fish-fact-sheets/brook-trout

Threatened Species Unit (TSU) (1998). Listing Statement: Clarence Galaxias Galaxias johnstoni. Parks and Wildlife Service, Hobart, Tasmania. Viewed: 25 February 2016 Available on the Internet at: http://dpipwe.tas.gov.au/conservation/threatened-species/lists-of-threatened- species/threatened-species-vertebrates

Galaxias johnstoni (Clarence galaxias) Conservation Advice Page 5 of 5