The Round Goby is a rapidly reproducing invasive fish native to the Black and Caspian seas in eastern Europe. A small, bottom dwelling fish, it was likely introduced to North America through the dumping of ballast water by ships from Europe. It was first observed in the St. Clair River north of Windsor in 1990 and has since spread to all of the Great Lakes and some inland water bodies. Round Gobies spawn multiple times per year and have reached densities of more than 100 per square metre in some areas.
Preferring water bodies with rocky and sandy bottoms, Round Gobies are voracious feeders that can eat as many as 78 Zebra Mussels per day. In addition, they eat Quagga Mussels, insects and other small organisms found on water bottoms and occasionally small fish and fish eggs. The Round Goby has a well-developed lateral line that detects water movement, which may help it to outcompete native fishes for food in murky water conditions.
No control methods exist at the present time, but research has been conducted on local control solutions involving fish poisons, pheromone from the urine of male Round Gobies and seismic guns.
Round Gobies are found in the Great Lakes and many of its tributaries, as well as some inland water bodies in southern Ontario, including Lake Simcoe, the Trent River, Rice Lake and parts of the Otonabee River.
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