Threatened Fishes Committee Report - May 2001
By David Crook
As promised in the last newsletter, a provisional list of threatened Australian fishes using the IUCN classification scheme has been prepared and is presented below. Due to the new listing of many marine threatened species, the number of listed species has dramatically increased from 91 to 210. This increase in numbers provides significant challenges for the committee in terms of keeping the list up to date, and increases the need for input from Society members with specialist knowledge of particular taxa. It is simply not possible for the committee members to keep fully up-to-date with the status of all 210 species.
The classifications for freshwater fish in the provisional list are based upon assessments conducted by Peter Jackson and Rob Wager in 1996. The conservation status of several of these species has been updated since then through the Threatened Fish Committee’s nomination process. The classifications for the marine and estuarine species are based upon the recommendations made in the draft “Conservation Overview and Action Plan for Australian Threatened and Potentially Threatened Marine and Estuarine Fishes” prepared by John Pogonoski, John Paxton and Dave Pollard. The provisional list is presented here to allow ASFB members an opportunity to raise any issues of concern prior to the list going before the committee for adoption at the annual conference in Perth.
Please take the time to go through the list so that any mistakes, misclassifications or opinions regarding the list are brought to the committee’s attention. Any changes to the provisional classifications will need to go through the normal nomination process (nomination forms are available from me on request). The new list is not perfect. However, it provides an opportunity for ASFB to present a relevant and up-to-date assessment of the conservation status of Australian fishes based upon the expertise of Society members. Any contribution of ideas or opinions regarding the new list will be greatly appreciated.
Lower Murray aquatic community nominated for listing in New South Wales
The Fisheries Scientific Committee is an independent group of scientists who advise the Minister for Fisheries in NSW of recommendations for listing of threatened species, populations and ecological communities, and of key threatening processes. The committee has proposed to list the aquatic community in the natural drainage system of the lower Murray River as an endangered ecological community. The proposal identifies the community as occupying the Murray, Murrumbidgee and Tumut rivers and all their tributaries in NSW downstream from the major dams of Hume, Burrinjuck and Blowering. The community includes all native finfish and aquatic invertebrates and is threatened by a number of common factors including river flow changes, river temperature changes, introduced fish species, clearing of riparian vegetation, removal of instream habitat, pollution, overfishing and salinisation. Seven out of the 23 native finfish species that are known to have occurred in this area are currently listed as threatened in NSW.
If the listing of the ecological community goes ahead, a recovery plan for the community will be prepared in consultation with major stakeholders and the general community. The recovery plan will seek to identify the current threats to the community and implement actions to reduce or remove those threats. The recovery plan will also identify who is responsible for recovery actions. There will be a number of management implications for State agencies, local government and so on that will ensure that the impact of any development on the ecological community must be taken into consideration in the approvals process. More information on the Fisheries Scientific Committee and its activities and current lists are available at www.fsc.nsw.gov.au
Pedder galaxias on the move!
Just a few years ago, Australia’s most endangered freshwater fish, the Pedder galaxias Galaxias pedderensis, was in danger of becoming the first Australian freshwater fish species to become extinct. It was threatened by loss of habitat as well as predation and competition from the introduced brown trout Salmo trutta and native climbing galaxias Galaxias brevipinnis. In 1991-92, to save the species, 31 fish were moved to Lake Oberon, a fish-free lake in the Western Arthur Range. As far as is known, Pedder galaxias no longer occur in what remains of their natural habitat (tributaries of Lake Pedder). However, recent population surveys by the Inland Fisheries Service and the University of Tasmania in January 2001 found that at least 500 adult Pedder galaxias are now present at Lake Oberon, with a large number of pelagic juveniles also observed. To further improve survival chances for the species, 52 adults from Lake Oberon were moved to a fish-free dam near Strathgordon in south-west Tasmania in March 2001. The dam had been modified by Hydro Tasmania and Inland Fisheries to be a suitable habitat for Pedder galaxias, with a weir-fed inflowing stream and barriers to fish invasion from the outflow. Additional moves to other sites will be considered if this one is successful.
What’s happened to Arthurs paragalaxias at Woods Lake?
The small Arthurs paragalaxias Paragalaxias mesotes is one of two native fish species that occur only in Arthurs Lake and Woods Lake on the Central Plateau. The other is the saddled galaxias Galaxias tanycephalus. Both species are threatened due to their very limited distribution and threats from trout predation and habitat changes in these Hydro Tasmania managed lakes. Arthurs paragalaxias is of particular concern as it hasn’t been seen in Woods Lake during several years of regular electrofishing surveys, and has therefore been listed on the Tasmanian Threatened Species Protection Act 1995 as Endangered. To determine whether the species was present but not seen by electrofishing because of the high turbidity in Woods Lake, fine-mesh fyke nets specially designed for catching galaxias were used. Several Arthurs paragalaxias were caught in Arthurs Lake, but none were collected in Woods Lake. These limited surveys need to be repeated more intensively, but further indicate that Arthurs paragalaxias may have disappeared from Woods Lake sometime between 1988 and 1998. A nomination is currently being prepared to have Arthurs paragalaxias listed as Endangered by the ASFB Threatened Fish Committee.
New populations of Oxleyan pygmy perch discovered
Jamie Knight, an honours student from Southern Cross University, recently discovered populations of the Endangered Oxleyan pygmy perch Nannoperca oxleyana in more than twenty new locations (Weekend Australian, 17-18 February 2001). According to the newspaper report, Jamie collected more than 500 fish from a series of creeks and waterholes around Broadwater National Park near the Queensland/NSW border. Wager and Jackson (1993) suggest that the major causes for the decline of the Oxleyan pygmy perch are negative interactions with introduced Gambusia and habitat degradation due to residential housing, forestry, mining and agriculture. Hopefully, the discovery of these new populations will lower the likelihood of losing this small, but unique fish.
Thanks to Andrew Sanger, Jean Jackson and Patricia Kailola for providing information used in this section.