Archived page, Submission to Fisheries Management Paper 174: The Translocation of Golden Perch, Murray Cod and Australian Bass, into and within Western Australia, for the Purposes of Recreational Stocking, Domestic Stocking and Commercial and Non-Commercial Aquaculture

Recfishwest is Western Australia's peak recreational and sportfishing body. It represents the interests of an estimated 645,000 Western Australians who go fishing and is recognised in this capacity by the Government of Western Australia, the WA Department of Fisheries and other government departments and authorities. Recfishwest has an interest in maintaining fishing experiences in inland freshwater systems and impoundments however we are extremely mindful of the need to ensure the integrity of the environment is not compromised.

General comments
Recfishwest believes that the overall tone of Fisheries Management Paper 174 attempts to nullify any endeavour to consider the introduction of the three species of fish discussed, while excluding key scientific information concerning historical introductions of these species into Western Australia.

Recfishwest considers the ecological risk of translocating Murray cod and Australian bass into Western Australian waters too high. Our submission therefore focuses on issues associated with the translocation of golden perch only. Also please note that Recfishwest has only ever advocated the introduction of golden perch into highly modified and contained impoundment environments and not river systems.

Recfishwest is concerned that scientists with significant experience assessing the impacts of non endemic species in dams in the South-West have not been incorporated into the Paper. There is no doubt that information resulting from these studies would have contributed to a more objective assessment of the risks.

The omission of the ornamental fish trade from the discussion paper particularly given the already significant impact of these species for similar consideration is a concern. As an already demonstrated avenue for possible disease introduction and exotic species introduction, the lack of policy with respect to the aquarium trade in effect compromises the holistic controls that such a policy wishes to manage.

The lack of a comprehensive assessment of all known translocations involving the species in question in Western Australia is a significant omission from the Paper. To merely list past introductions without exploring the impacts of these introductions is misleading. The three species have been stocked into WA waters for decades and there is a need to look to earlier research into the predicted impacts, or carry out the research if it hasn't been done.

A four-year study funded by the Natural Heritage Trust and the WA Department of Fisheries, titled Human impacts on marron populations in the South-West, was developed and conducted to quantify the impact of past translocations (Whisson 2003). Several sites were selected and the ecology of each system described biannually over four years. Macro invertebrates and finfish (introduced and native) were extensively sampled and population characteristics recorded.


Golden Perch
Records and historical accounts of stocking of these Murray-Darling species exist and should be collated. For example; Roughley (1961) states that: In 1893 and 1894 several hundred callop (golden perch), from ¼ to ½ pound in weight, were transported by ship from Adelaide to Western Australia where they were released in the upper reaches of the Swan River and in a lake near Albany and became successfully acclimatised. Note however that these fish did not establish reproductively viable populations.

Other accounts of past stockings exist - locals in Waroona recall golden perch being stocked into Lake Moyanup (Drakesbrook Weir) many years ago. Extensive sampling of this site over four years by Dr Glen Whisson (2003) revealed no evidence of golden perch, supporting scientists who believe that this species will not breed in closed impoundments. Every effort should be made to verify these accounts/records and quantify the nature of the resulting impact.

Recfishwest believes that a significant issue not dealt with conclusively was the capacity of golden perch to establish a viable population in Western Australia. We know golden perch were stocked 20 years ago so there seems an obvious opportunity to determine whether breeding has taken place. There is however no evidence whatsoever that they have successfully bred.

Claiming that the golden perch have been bred in farm dams and water supply impoundments necessitates further explanation. There is a considerable difference between cues for breeding opposed to cues for ovulation. Having eggs that are negatively buoyant and take 20+ hours to hatch makes breeding in still-water impoundments highly improbable, however ovulation due to a summer rainstorm is quite conceivable.

It is mentioned that golden perch require live food like small redfin perch and yabbies. An experimental stocking at a closed impoundment (Drakesbrook Weir?) may be useful given the extensive data accumulated at this site over four years as part of Dr Whisson's NHT sponsored research. This research would provide a valuable baseline from which to monitor a trial stocking of golden perch.

The statement on page 40 "Introductions should be seen as irreversible, with eradication almost impossible" obviously refers to species that can breed in the environment that they are translocated to. If the receiving environment does not include the conditions necessary for a species to breed, it would die. This is supported by recognition within the Management Paper of the limited success of stock enhancement in Western Australia, as species such as golden perch will not breed in still waters. Recfishwest believes there is a need to quantify past translocation experiences to investigate whether golden perch have established breeding populations. If they have not bred in Western Australia, then we are in an ideal situation to enhance impoundment-based fisheries.

Conclusion
Recfishwest does not support the conclusions drawn on the risk of golden perch for stocking impoundments in the south-west base on our more objective assessment of the risk. According to the Recfishwest policy on translocation, we believe that golden perch are more correctly a level four rather than a level two risk as portrayed by the paper and thus worthy of further investigation. (See attached Recfishwest Translocation Policy) This is based upon the Western Australian work of Dr Glen Whisson and the widely cited work of Rowland and Reynonlds as well as the experience of our Executive Director who was in charge of the New South Wales stocking program in the past.



This page last updated on April 2004.