It sounds like a tabloid concoction: goldfish the size of dinner plates! But Canadian media outlets such as the National Post are trumpeting headlines of that variety—and they happen to be true. Biologists in Alberta are asking people to stop flushing their cute little goldfish, because they're apparently breeding like rabbits in the province's waterways, reports the CBC. And freed from the confines of their aquariums, they're growing to impressive sizes, as one biologist found out when he spotted kids fishing in a stormwater pond in Fort McMurray and investigated further. “They removed 40 goldfish from that one pond and they were finding four different age classes, which suggests they’re breeding in the wild," an Alberta environmental official tells the Edmonton Journal.
"The smallest one was the size of half your pinky and the biggest one was the size of a dinner plate," she says. It's part of the reason Alberta is pushing a "Don't Let It Loose" campaign warning people about the potential danger to natural habitats of flushing their fish. Alberta also is apparently unique in North America in having a big problem with a small fish called the Prussian carp. As in, hundreds of thousands of the non-native fish are now estimated to be in the province. One theory is that they've been introduced by new arrivals who traditionally fish for them back home. Either way, "something weird is happening," says the Alberta official. (Goldfish invasions happen in the US, too.)