The tubby, out-sized goldfish, which can weigh in at up to three kilograms, according to the government, is a highly invasive species that reproduces rapidly. It’s not known how it first entered Alberta’s waterways, although it has been there since at least 2015. It is able to survive out of water “for relatively long periods of time” and is also able to outcompete native fish species. “Many invasive carp were imported as pond or aquarium species or sold in Asian food markets,” says a government fact sheet from 2015 that was updated in 2018.