When goldfish and koi are swimming around in small bowls and aquariums they don’t seem like ferocious, ecosystem-destroying sorts, but it turns out that they are.
Researchers at Australia’s Murdoch University have discovered that what were once likely quiet, tiny pets are wreaking havoc in rivers throughout the western parts of the country.
Part of the problem is that after they’re set free in the wild, they don’t stay quite so little. The size of their environment is a very large factor in how big they end up being, so once they make it to spacious waters they expand exponentially.
As they become huge, they develop appetites to match, and, who would have guessed, they’re very aggressive about getting the nourishment they need. Often times, that happens at the expense of the wellness of species native to the waterways.
Also posing a significant threat to the aquatic beings that are indigenous to the environment are the diseases and parasites their new, super-fish neighbors can spread.
Further complicating the problem is that goldfish and koi are such skilled survivors, eradicating them is a very tough job. Thus, said one of the researchers, the seemingly benign pets are, “one of the major global threats to aquatic biodiversity.”
