This conservation advice was approved by the Minister/Delegate to the Minister on: 26/3/2008

A statement for the purposes of approved conservation advice (s266B of the Environment Protection and Biodiversity Conservation Act 1999) Approved Conservation Advice for Ophisternon candidum (Blind Cave Eel)

This Conservation Advice has been developed based on the best available information at the time this conservation advice was approved.

Description

Ophisternon candidum, Family Synbranchidae, commonly known as the Blind Cave Eel, is a pure-white fish growing to 40 cm, with an eel-like body, no eyes, and a thin rayless membrane around the tip of the tail. Conservation Status The Blind Cave Eel is listed as vulnerable. This species is eligible for listing as vulnerable under the Environment Protection and Biodiversity Conservation Act 1999 (Cwlth) (EPBC Act) as, prior to the commencement of the EPBC Act , it was listed as vulnerable under Schedule 1 of the Endangered Species Protection Act 1992 (Cwlth). This species is also listed as rare under the Wildlife Conservation Act 1950 (Western Australia) and on the Wildlife Conservation (Specially Protected Fauna) Notice 2006(2) (Western Australia). Distribution and Habitat The Blind Cave Eel is known to occur on the Cape Range peninsula in the north-west of Western Australia (Humphreys, 1999a; Romero & Vanselow, 2000). It occurs within the Rangelands (Western Australia) Natural Resource Management Region. The species inhabits the caves and underground waters of the narrow coastal plain of the peninsula and the foothills of Cape Range (Humphreys & Feinberg, 1995; Humphreys, 1999a). These waters are markedly stratified, (Humphreys, 1999b; Seymour et al., 2007), ranging from freshwater at the surface to full seawater salinity at depth. While affected by marine tides, the waters lack surface connection with the sea (termed anchialine ecosystems: Humphreys, 1999b). The fish traverse this range of salinity (Humphreys et al., 2006). The Blind Cave Eel is the world's longest and one of only two vertebrate known from Australia that are restricted to subterranean waters, the other occurring in the same waters (Humphreys, 2001). Owing to its length and bottom living habit, the Blind Cave Eel is unlikely to be taken by trapping or netting and all records have been derived from sites large enough for people to access groundwater, such as caves and pastoral wells. Records have, therefore, been limited to the upper part of the anchialine system. At most three individuals are known from any given site. The distribution of this species is not known to overlap with any EPBC Act-listed threatened ecological communities. Threats The main identified threats to the Blind Cave Eel include sedimentation from mining and construction, canal development, water abstraction, point source pollution from sewage, landfill, dumping and mining; and diffuse pollution from urban development (Humphreys, 2001, 2002). Open sites may serve to permit the invasion by feral fish, especially guppy’s (Poecilia sp.) (Plath et al., 2007).

Ophisternon candidum Conservation Advice – Page 1 of 2 This conservation advice was approved by the Minister/Delegate to the Minister on: 26/3/2008

Research Priorities Research priorities that would inform future regional and local priority actions include: • Determine the pattern of genetic variation within the range of the Blind Cave Eel. • More precisely assess population size distribution, ecological requirements and the relative impacts of threatening processes. Regional and Local Priority Actions The following regional and local priority recovery and threat abatement actions can be done to support the recovery of the Blind Cave Eel. Habitat Loss, Disturbance and Modification • Monitor known populations to identify key threats. • Monitor the progress of recovery, including the effectiveness of management actions and the need to adapt them if necessary. • Manage any changes to hydrology that may result in changes to the water table levels, increased run-off, sedimentation or pollution. • Manage any disruptions to water flows. • Minimise adverse impacts from land use within the range of the groundwater ecosystem. • Prevent point source pollution of groundwater by petrochemicals, leachates and sewage. • Ensure sediments do not enter groundwater ecosystem. • Investigate formal conservation agreements such as the use of covenants, conservation agreements or inclusion of habitat in reserve tenure. Predation or Competition • Manage known sites to exclude/control introduced fish species, and the associated introduction of disease/parasites. Conservation Information • Raise awareness of the species within the local community.

Information Sources Humphreys, WF 1999a, ‘The distribution of the Australian cave fishes’, Records of the Western Australian Museum vol.19, pp. 469-472. Humphreys, WF 1999b, ‘Physico-chemical profile and energy fixation in Bundera Sinkhole, an anchialine remiped habitat in north-western Australia’, Journal of the Royal Society of Western Australia vol.82, pp. 89-98. Humphreys, WF 2001, ‘ veritas Whitley 1945 (), a remarkably versatile cave fish from the arid tropics of northwestern Australia’, Environmental Biology of Fishes vol.62, pp. 297-313. Humphreys, WF & Feinberg, MN 1995, ‘Food of the blind cave fishes of northwestern Australia’, Records of the Western Australian Museum vol. 17, pp. 29-33. Humphreys, WF, Shiao, JC, Iizuka, Y & Wann-NianTzeng, W-N 2006 ‘Can otolith microchemistry reveal whether the blind cave gudgeon, (Eleotridae), is diadromous within a subterranean estuary?’, Environmental Biology of Fishes vol. 75, pp. 439-453. Plath, M, Hauswaldt, JS, Moll, K, Tobler, M, Garciadeleon, FJ, Schlupp, I & Tiedemann, R 2007, ‘Local adaptation and pronounced genetic differentiation in an extremophile fish, Poecilia Mexicana, inhabiting a Mexican cave with toxic hydrogen sulphide’, Molecular Ecology, vol. 16, pp. 967-976. Romero, A &Vanselow, PBS 2000, ‘Threatened fishes of the world: Ophisternon candidum (Mees) (Synbranchidae)’, Environmental Biology of Fishes vol. 58, pp. 214. Seymour, JR, Humphreys, WF & Mitchell, JG 2007, ‘Stratification of the microbial community inhabiting an anchialine sinkhole’, Aquatic Microbial Ecology, vol 50, pp. 11-24.

Ophisternon candidum Conservation Advice – Page 2 of 2