Next
Previous
Australian Capital Territory Implementation Report 2004–2005
Driving Action 5: Protecting Threatened Native Fish Species
Highlights
New conservation strategy for aquatic and riparian species
ACT Action Plans for five threatened fish species (Trout cod, Macquarie perch, Silver perch, Two-spined blackfish, and Murray River crayfish) are to be amalgamated into a single Aquatic Species and Riparian Zone Conservation Strategy. Drafting of the strategy was largely completed in 2004–2005 with public consultation to be conducted in 2005–2006.
Monitoring of threatened fish abundance
Monitoring of fish populations in the Cotter River in early 2004 revealed that the abundance of the threatened Two-spined blackfish recovered substantially from the declines after the 2003 bushfires. Young of year and juvenile fish dominated the population, indicating successful recruitment despite large instream sediment loads. However, monitoring in 2005 indicated that numbers of this species were substantially lower than the 2004 levels, and had almost returned to the post-fire levels of 2003.
Management of threatened fish
View enlargementAs part of the post-fire review of Canberra’s water supply, Cotter Reservoir was brought back on-line as a component of the long-term domestic water supply infrastructure for the ACT. This reservoir had not been used since the late 1960s, and contains the last remaining viable population of the threatened fish Macquarie perch in the ACT. As part of the recommissioning of Cotter Reservoir, the potential impacts on Macquarie perch of use of the reservoir are being investigated. Of concern were the potential draw-down levels for the reservoir, which could present significant issues for fish passage through accumulated sediment beds at the top of impoundment, and alienation of macrophyte beds (important habitat for adult fish). An adaptive management approach is being pursued, with monitoring of the impacts of draw-down levels to be conducted over future years.
Workshop on fish virus
A workshop on Epizootic Haematopoietic Necrosis Virus (EHNV) and its ramifications for future water supply options for the ACT was held in Canberra in August 2004. Representatives from NSW Fisheries, Victorian Department of Primary Industries, University of Sydney, Commonwealth Department of Environment and Heritage, ActewAGL, ACTEW Corporation and Environment ACT attended. EHN virus has adverse impacts on a range of native fish species, including the nationally endangered species Silver perch and Macquarie perch. The virus is known to be carried by two alien species, Redfin perch and Rainbow trout. The lack of recent research into the virus, particularly into the impacts of the virus on wild fish populations was highlighted and a funding proposal will be prepared in 2005–2006.
