How Will Invasive Species Impact the Future of Fisheries?
D. Andrew R. Drake and Nicholas E. Mandrak
A good way to determine how invasive species will impact the future of fisheries is to learn from the past. The Laurentian Great Lakes ecosystem has one of the best documented histories of fisheries and biological invasions. The earliest known exotic fish, Common Carp Cyprinus carpio, was intentionally introduced into the Great Lakes in the mid-1800s to establish a fishery for European settlers who desired a familiar species for food and sport. Subsequently, similar intentional introductions of a variety of species, such as Brown Trout Salmo trutta and Pacific salmons Oncorhynchus spp., have repeatedly occurred and continue to this day. Unintentional introductions also played a role in the introduction of nonnative species. Alewife Alosa pseudoharengus, a small forage fish, invaded the Great Lakes during the 1930s through newly constructed canals that provided connections between the Great Lakes and to watersheds beyond the basin. Ruffe Gymnocephalus cernua, another small species, invaded the Great Lakes years later through ballast water in ships that used the canals.