I saw this article on the "Fishing News' News Wire; Thought Quinte anglers would be interested.
David aka Superdad
NEW: Alewife & Goby main diet of Cormorants in Hamilton Harbor, Lake Ontario
Mark Lamb -- Mon, Sep/26/05
Angler/commercial targeted fish species accounted for less than 1%.
Populations of the invasive round goby have expanded dramatically since their discovery in the Great Lakes in 1990. The abundance of these fish and possible competitive displacement of native species from aquatic food webs suggest that they will become an important prey item for predatory birds and sport fish. To date, there is very little information on the predation of round gobies by fish-eating birds in the Great Lakes.
Scientists used a manual massage technique to stimulate regurgitation by double-crested cormorant chicks in ground nests from colonies in Hamilton Harbor, western Lake Ontario, during the 2002 nesting season. They collected and
identified all fish species present in regurgitated mass. For tree-nesting birds, they collected fish that were regurgitated and fell to the ground as a result of targeted disturbance of particular nest trees. At all locations and times, alewife was the most abundant fish species present by a large margin. The second most abundant species was the round goby, which was present in the regurgitated stomach contents of chicks in a total of 18% of nests surveyed, and made up 2-11% of all individual fish specimens identified.
Their results show that the round goby is already an important food item for breeding cormorants in Hamilton Harbor, despite relatively recent establishment of goby populations in western Lake Ontario.
Fish species of sport or commercial interest were detected in samples with extremely low frequency (
Great Lakes Sport Fishing Council
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