Up to the gills in goldfish: Large invasive fish a problem in B.C. waters: expert

KAMLOOPS, B.C. — A researcher says pet owners who dump their unwanted goldfish into British Columbia's waterways are putting native fish populations at risk.

Brian Heise, an associate professor in the department of natural resource sciences at Thompson Rivers University, says thousands of large, invasive goldfish — some as big as footballs — have multiplied in bodies of water around the province.

He says female goldfish can release 50,000 eggs at a time, three times a summer, they compete with native species for food and space, and carry diseases that can spread to other fish, including the salmon population.

Over the last decade, Heise says goldfish populations have spread from the Vancouver area to lakes in the northern and Interior parts of the province.

He says the province needs to continue funding an expensive practice called electrofishing where electric current is passed through the water to stun the fish, allowing them to be scooped out.

The researcher also says work needs to be done at pet stores so customers can return unwanted animals instead of dumping them.

This report by The Canadian Press was first published March 3, 2023.

The Canadian Press