New populations of endangered fresh water fish found

Murdoch University researchers have discovered new populations of an endangered fresh water fish, the Little Pygmy Perch, near Denmark in Western Australia's south.

Dr David Morgan and Dr Stephen Beatty from Murdoch University's Freshwater Fish Group and Fish Health Unit (FFGFHU) first discovered the species in 2009 near Denmark in a 3km stretch of the Hay and Mitchell rivers.

Now, in conjunction with Dr Paul Close from the University of Western Australia's Centre for Excellence in Natural Research Management (CENRM), the research team have found the species in low numbers in two neighbouring catchments.

"This is an incredibly exciting discovery as it greatly enhances the future prospects of the Little Pygmy Perch surviving in the wild," Dr Beatty said.

The research study is also gaining valuable ecological information on the endangered Western Trout Minnow and the Balston's Pygmy Perch and has involved sampling more than 80 sites and the capture and identification of 45,000 fish.

"We undertook the first mark-recapture program of small endemic freshwater fishes in a south-west river which revealed that the summer population size of the Little Pygmy Perch in the Hay River pools was approximately 100 to 200 fish, compared with more than 14,500 common Western Pygmy Perch; so we had major concerns for its long-term survival," Dr Beatty said.

"While our group has already surveyed more than 2000 sites in Western Australia, this study has demonstrated that there is still much to learn about our native fish and obtaining this ecological information in natural environments is crucial to prioritising management actions for their long-term conservation."

The study is now determining the breeding habitats, spawning times, movement patterns and threats to all three populations of the Little Pygmy Perch and the other endangered species.