The Great Lakes are facing invasive species that originated in homes across the United States. Common goldfish (Carassius auratus) released into lakes, rivers, and ponds by pet owners have been wreaking havoc for decades and scientists are trying to follow the fish to solve the problem. The species of freshwater fish native to Asia is usually only about five inches long in a home aquarium, but can grow to up to 19 inches long and tip the scales at nine pounds when they swim freely.
[Related: Whatever you do, don’t set your pet goldfish free in a stream.]
In the Great Lakes, they’re an invasive species that will “eat anything and everything,” Fisheries and Oceans Canada aquatic research biologist Christine Boston told The New York Times. These seemingly benign household pets can harm native marine wildlife, uproot plants, contribute to harmful algal blooms, and eat vegetation in the environmentally and economically sensitive region.
According to The Ohio State University College of Food, Agricultural, and Environmental Sciences, invasive goldfish will eat the eggs of native fish species. They will also take over the spaces that other fish will use for reproduction and shelter. The goldfish are even able to reproduce with the native common carp to create bigger hybrid species that are equally harmful.
A study published in November in the Journal of Great Lakes Research details how an invasive population of goldfish in Hamilton Harbour has been changing the area. The harbor in Lake Ontario southwest of Toronto is one of the most environmentally degraded areas of the Great Lakes due to industrial activity and building. The team captured 19 adult goldfish between June 2017 and October 2018. They implanted transmitters in the fish that the scientists used to track where the goldfish swam.
The team saw that the goldfish spent time in the same area over the winter and returned to the same places to spawn every year. They…
Read the full article here