Implication of translocated fishes in the apparent extinction in the wild of the Lake Eacham rainbowfish, Melanotaenia eachamensis

Abstract

The Lake Eacham rainbowfish, M. eachamensis, has been recorded from only Lake Eacham, a small crater lake in northern Queensland. Colonisation by four Australian fishes not native to the lake and the concomitant decline of the rainbowfish prompted a detailed survey in 1987. Intensive sampling failed to reveal any rainbowfish. It appears that the Lake Eacham rainbowfish no longer exists in its natural habitat. Although the cause of the demise of the Lake Eacham rainbowfish cannot be proven, temporal and trophic evidence implicated the translocated species. Aquarium stocks are being maintained to make feasible the consideration of a restocking programme in the future. This case study indicates the need for strict adherence to scientifically responsible policies on fish translocation programmes.