The round goby is invading Great Lakes tributaries.
The goby, an aquatic invasive that spawns aggressively and competes with native fish for habitat and food, has been in the lakes for a couple of decades.
But new research from the University of Toronto, the Ontario Ministry of Natural Resources and the University of Guelph has identified "a drastic invasion of round goby into many Great Lakes tributaries," including several areas of the Thames, Sydenham, Ausable and Grand rivers in Ontario, scientists said in a news release.
A number of the affected areas are known as "species-at-risk" hot spots.
Gobies came into the lakes likely through ballast water from ocean-going ships. It's been thought that the gobies wouldn't survive in high diversity areas like tributaries. Not anymore.
By the way: If you catch a round goby, don't re-release it or use it as bait.
The goby study has been published in the journal Biological Invasions.