Giant goldfish the size of dinner plates are taking over the ponds and lakes of Alberta, Canada, and environmental officials have taken matters into their own hands.

The Alberta Environment and Parks department is launching Don't Let It Loose, a campaign that aims to correct the misinformation that releasing pet goldfish into the wild is a humanitarian thing to do.

Goldfish are small and cute when kept as pets living in the restricted space of an aquarium and on food provided by their owners. However, when they are let out into the wild, goldfish are actually very sturdy and can survive the harsh winters and low-oxygen waters of Alberta.

Since they have no natural predators in the area, the goldfish compete for food and other resources with the native species in the area and win, eventually ballooning to monstrous sizes and upsetting the natural balance of the ecosystems they are invading.

In the regional municipality of Wood Buffalo in northeastern Alberta, for example, the department has discovered 40 goldfish taking over a small storm water pond alone. In Fort McMurray, just 275 miles north of Edmonton, each generation of goldfish becomes bigger and bigger until they become the predator and the smaller native fish become the prey.

"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 Kate Wilson, aquatic invasive species coordinator at the department. "It's quite a surprise how large we're finding them and the sheer number."

Environment officials believe there could be as many as "hundreds of thousands" of goldfish released into the lakes and rivers of the province and they are concerned that the people releasing the pets into the wild think it is the humanitarian thing to do. Wilson says about a third of invasive species that are released into native aquatic environments come from aquariums and the ornamental trade.

"We really need to correct misinformation," she said.

The Don't Let It Loose campaign is primarily targeted at pet stores and spiritual groups that purchase thousands of pets and release them into the wild, with the aim of educating the public about the consequences of letting loose an invasive species as an act of kindness toward the animals.

For people who no longer want to take care of their pet goldfish, the department recommends that they give the fish to another owner, return it to the pet store, donate it to a school, or ask a veterinarian about humane disposal.