Does an increase in light penetration affect how predators in lake food chains find their prey?
Yes, says Dr. Lars Rudstam, Associate Professor in the Department of Natural Resources at Cornell University. Increased predation is one consequence of the illumination of the food web associated with the increasing water clarity in the Great Lakes. In several New York Sea Grant funded projects, Rudstam, along with his colleagues and students at Cornell, the USGS Great Lakes Science Center, and the Canadian Centre for Inland Waters, has been examining the interaction of forage fish and invertebrates in Lake Ontario and predicting trends in their populations. The main forage fish of economically-important sportfish species such as Chinook salmon and other salmonids in Lake Ontario is the alewife. The relatively high abundance of alewife is the reason for the faster growth of Lake Ontario salmon compared to those in other Great Lakes. Alewife may be switching from a diet consisting primarily of zooplankton to one that also includes the opossum shrimp, Mysis relicta, a small shrimp that f
