Australians have found instances of the bacterium Edwardsiella ictaluri in imported fish and aquariums in Australia and are taking measures to test for it in the wild. The disease causes Enteric Septicemia of catfish and is often found in cultured channel catfish in the United States. Murdoch University’s Freshwater Fish Group and Fish Health Unit will survey wild populations of Australian catfish to ensure the disease hasn’t made the jump to Australian waterways in Queensland, the Northern Territory, and Western Australia’s Kimberley region.
Although the disease is mostly confined to catfish, it has also been found in other freshwater fish species in the United States, China, Vietnam, and Japan, according to Murdoch University Associate Professor Alan Lymbery. Lymbery did say that there has not yet been any evidence that the disease is found in wild populations of fish in Australia. Symptoms of the disease include fish hovering with their head up and tail down in a vertical fashion, swimming in circles, and chasing their tails.
“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,” Lymbery said. He also reiterated the importance of not releasing aquarium fish, including goldfish, into any bodies of water in Australia. The study will be overseen by Murdoch University with collaboration from the Western Australian Department of Agriculture and Food, the Northern Territory Department of Resources, CSIRO and James Cook University.