Now that’s a big goldfish!
Unloved pet fish are flooding Australian waterways, introducing diseases and bullying native fish. In large waterways, goldfish and koi can grow to up to 10 times the size of native species and compete with them for habitat and food.
In Western Australia’s southwest, exotic fish bought for aquariums are continually being dumped in lakes and rivers, decimating native fish populations.
Dr Jeff Cosgrove, Swan River Trust’s river science environment officer, says it’s a massive environmental issue for the region.
According to Dr Cosgrove, aquarium owners get sick of their fish and dump them into areas they sees as having little environmental significance.
‘They’re dumping them into a man-made lake, say, in a housing estate, and they think, “What’s the harm?” At least it will have a nice home and I don’t have to look after it.”
‘Through the drainage system, these fish simply spread and they go out into our beautiful rivers.’