Impacts of recent Invasive species on nearshore fishes

Invasive species have impacted Lake Michigan's fisheries for 70 years. The passage through the Welland Canal by sea lamprey, after it invaded Lake Ontario, led to its establishment in Lake Michigan where it was first seen in 1936 (Christie and Goddard 2003). A combination of overfishing and sea lamprey predation led to the extirpation of lake trout (Coble et al. 1990; Hansen 1999) and to the extirpation or extinction of several deepwater ciscoes endemic to the Great Lakes (Coon 1999). Alewives, probably through interference with reproduction, likely caused the decline in abundances of deepwater sculpins and yellow perch during the 1960s and may have delayed the recovery of burbot in Lake Michigan until the 1980s (Madenjian et al. 2002). From 1959 to 1999, the rate of new introductions into the Great Lakes has increased to more than one species per year (Grigorovich et al. 2003), resulting in the establishment of numerous invaders during the past 20 years. In this report, we focus on (1) the status of six recent invasive species during 2000-2004, (2) the identity of other species that could invade in the near future, (3) examples of their impacts on the nearshore fish community, and (4) the implications for fishery management.