In article ,
says...
I keep goldfish in my outdoor pond, as well as in my aquarium. They can
live in lakes, rivers, etc... and as such, should never be released into the
wild. The can outcompete native species and do great damage to ecosystems.


I certainly agree they shouldn't be released into the wild, but
I seriously doubt the "outcompete" part. For one thing, their
extreme coloration would attract predators like ....
well, like a raccoon to a goldfish. You can't compete at all
if you're dead.

Gunther