Can cormorants help control Great Lakes invaders?

By ERIC FREEDMAN
Capital News Service
LANSING — Double-crested cormorants are the bane of many Great Lakes anglers, devouring prize game fish and damaging the sport and commercial fishery. At least that’s a widely held belief about these birds — and a generally wrong one, Northern Illinois University researchers say. Cormorants’ fish-stealing rep may be a bum rap — and the truth is more complex, as the first dietary study of cormorants in southern Lake Michigan shows. Even better news: The cormorants are chowing down instead on invasive species — mainly alewife, round goby and white perch — which together accounted for 80 to 90 percent of their diet. “Because this is the first such study to be completed in southern Lake Michigan, its results will help to inform discussion among local stakeholders and will provide valuable data to other researchers studying cormorant diet in the region,” said lead author Patrick Madura, who led the study as a master’s student.