Murdoch University’s Freshwater Fish Group and Fish Health Unit is undertaking a survey of freshwater catfish to provide further evidence that Australian wild fish populations are free of a bacterium found in imported aquarium fish.
The study, funded by the Australian Government Department of Agriculture through the Fisheries Research and Development Corporation, will see researchers examine wild catfish in rivers throughout Queensland, the Northern Territory and the Kimberley region of Western Australia.
They’ll be testing for the bacterium Edwardsiella ictaluri, which causes Enteric Septicemia of Catfish (ESC).
“ESC is a major disease of cultured channel catfish in the USA, and has also been found in other species of freshwater fish in the USA, China, Vietnam and Japan,” said Murdoch Associate Professor Alan Lymbery.
“Although it has been detected in imported fish and aquarium facilities in Australia, there has been no indication of the disease in wild fish populations.
“However, the fact that it has been detected suggests adopting a proactive approach is best, as we know from experience that an exotic disease entering the Australian ecosystem can have a hugely adverse environmental impact.”
Professor Lymbery said while ESC can be found in a wide range of freshwater fishes, it occurs most commonly in catfish.
Affected fish often swim in tight circles, chasing their tails, or hang in the water with their head up and tail down.
“ESC is a reportable disease, and the relevant state or territory should be notified if it is suspected in either wild or captive fish,” Professor Lymbery said.
Professor Lymbery said the presence of the bacterium was a timely reminder to the public to avoid releasing ornamental fish into natural waterways, including goldfish.
The study is a collaborative venture between Murdoch University, the Western Australian Department of Agriculture and Food, the Northern Territory Department of Resources, CSIRO and James Cook University.