Releasing Tropical Fish in the Wild

In the Great Lakes of Canada and the St Lawrence River, there is already an ecological disaster. As part of a study done by Great Lakes Institute for Environmental Research and Redpath Museum, McGill University, a poll of pet owners was taken in Montreal. Over 7% admitted to releasing their fish into local lakes because they have become bored with them or they grew too large and or turned too aggressive.

Altogether Montrealers release over 10,000 fish yearly into the Great lakes or the St Lawrence Seaway. Most of these tropical fish could not survive cold Canadian winters and soon die off as the water begins to get chilled.

Non-Native Fish Species in the Great Lakes

Among the few species that can adapt to the cold winters, two species have become well established in local water ways. They are the Koi carp and Goldfish. Another other species is the White Cloud Minnow where over 200 species are released each year in the Montréal region alone. Scientists at McGill University say that there is more than enough White Cloud Minnows species to breed and to become a permanent invasive species in the region.

Another fish that can survive the cold Canadian winters is the Hog Choker but it is too rare to have sufficient numbers released to become established in the area and to propagate.

Non-Native Fish Species in Vancouver

Where Montreal experiences long, cold winters, other parts of Canada have shorter and milder winters such as Vancouver and Victoria. Based on the same study by Great Lakes Environmental Research and Redpath Museum, McGill University, researchers have found over nine different species of commonly discarded tropical aquarium fish in lakes and ponds in the Vancouver area.

Non-Native Fish Species in Lake Okeechobee

Florida’s Lake Okeechobee is being overrun by non-native fish. Over 55 species of tropical fish are released yearly by Miami residents. The tepid water of the lake enables fish to survive, as opposed to the colder waters in Canada.

What to do with Unwanted Fish

First of all, do not release them into local lakes and rivers. Most fish don’t survive and the ones that do survive can kill other fish that are native to the waters. The best thing to do is to give or sell the fish to people who are willing to raise them. Some pet stores will allow fish trade-ins or donations. Some public aquariums will accept rarer species.

With thousands of fish released annually, it takes very little time for a breeding colony to establish and eventually overtake rivers and lakes.

Sources:

Biodiversity and Conservation: Great Lakes Institute for Environmental Research, University of Windsor and Redpath Museum, McGill University

White Cloud Mountain Minnow

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