Native freshwater fish in habitats over 700,000 square kilometres from Busselton to Geraldton to Northam will be surveyed for the first time by researchers at The University of Western Australia and the Department of Fisheries.
The massive survey, which includes species listed as critically endangered and vulnerable to extinction, will determine if there is a serious large-scale decline in freshwater fish biodiversity in WA, as research suggests.
UWA researcher Dr Craig Lawrence said native fish played an important role in the ecosystem. As they eat mosquito larvae, the most immediate concern is the impact that their loss could have on Ross River virus and Barmah Forest virus in humans. In the longer term with climate change, dengue fever and malaria could become a concern if the natural predators of mosquitoes (native fish) are no longer present in water bodies.
The survey will be carried out as part of an $850,000 research grant from the State Government and will also involve UWA researcher Associate Professor Phil Vercoe.
Dr Lawrence said $150,000 of the funding would be used to undertake DNA testing of native fish to determine genetic variation among populations. "This will support our restocking efforts and enable us to focus on those populations at greatest risk of extinction," he said.
The researchers will work with native freshwater species such as minnows, pygmy perch, night fish and Balston's perch. An artificial stream will be built at the Department of Fisheries' Pemberton Freshwater Research Centre.
"This funding will enable significant infrastructure modifications to our lab to increase native fish breeding/production and environmental control. We will also be constructing an artificial wetland for teaching and research at the Aquaculture and Native Fish Breeding Laboratory at the UWA Shenton Park Field Station," Dr Lawrence said.
"Native fish are endemic to the south west of the State but populations on the Swan coastal plain are now fragmented and a recent honours project by UWA student Jenny Major showed they were absent from many of the 30 waterbodies in Perth that she sampled.
"Is this result due to the small sample size, or is it indicative of a serious large scale decline in freshwater fish biodiversity in WA? This funding will be used to undertake the survey to answer this question."
UWA has been working with the Department of Fisheries since the late 1990s to develop techniques for breeding and rearing several species of native fish. This includes the development of the UWA Shenton Park collaborative facility (Aquaculture and Native Fish Breeding Laboratory) since 1994, the largest facility of its type in Australia.
Existing departmental and University facilities will be modified to increase freshwater native fish production for restocking water bodies.