Or, as the CBC notes: "Goldfish the size of dinner plates are multiplying like bunnies."
"It's quite a surprise how large we're finding them and the sheer number," Kate Wilson, aquatic invasive species coordinator at Alberta Environment and Parks, told the broadcaster.
In one case, the municipality of Wood Buffalo pulled 40 of the domestic fish species from a stormwater pond.
"That's really scary because it means they're reproducing in the wild, they are getting quite large and they are surviving the winters that far north," said Wilson.
Forty! That does seem bad, doesn't it? And I'd like to remind you that these goldfish are surviving (and growing) in Canada, where it's cold.
"Their size is limited in the tank, but when you release it into the wild, that doesn't exist anymore," Wilson told The Post.
Like other species of carp, the domestic goldfish Carassius auratus will basically keep growing as long as water temperatures and food resources support it. There are obviously limits -- you're not going to accidentally create fishzilla if you overfeed your goldfish -- but given a big body of water with tons of food and warm summers, a fish is bound to get supersized.
Then you end up with a bunch of goldfish bruisers competing with local fish for resources, and you better believe the fish you flushed will give native species a run for their money. Plus, some scientists say, goldfish feces might help support certain types of algae, leading to algal blooms that further disrupt the eco-system.
The CBC reports that a campaign designed to curb this trend, called Don't Let It Loose, will "focus on educating Albertans about the dangers of releasing domestic fish into nature."
If people are dumping their aquariums, Wilson explained, they're also dumping the water it holds, which can carry disease and parasites. What's more, the goldfish can survive in poor water conditions, she said, and "could be competing with our native species for both food and habitat."
Canadians aren't the first to encounter a problem like this, of course. Consider the following reports:
In early 2013, a fisherman on Michigan's Lake St. Clair caught a goldfish that weighed a staggering three pounds and measured about 15 inches in length.
"I thought I had a big perch on," the man recalled. "Um, definitely not a perch."
He added: "Everybody wants to just dump them out ... and let them be free, and this is what they turn into."
He told Detroit's NBC affiliate that he planned to mount the giant goldfish on his wall.
Earlier this year, Colorado Parks and Wildlife officials said goldfish were taking over Teller Lake in Boulder.
"These are fish from a store I imagine," fish and wildlife spokesperson Jennifer Churchill told Denver's KUSA. "They can out-compete the native fish."
Still, aquatic biologist Ken Kehmeier told the Daily Camera, the presence of goldfish where they shouldn't have been "is an issue that anyone concerned with our environment should know about."
"It seems to be an emerging issue in our society and culture, that releasing pets into the wild is the humanitarian thing to do," Wilson, the Canadian invasive species expert, told Fort McMurray Today. "If a species as benign as a goldfish can survive winters in Alberta, that is a serious cause for concern."