Since Spring 2005, a number of die-offs have occurred in the Great Lakes area, including muskellunge, freshwater drum, round goby, yellow perch, smallmouth bass, bluegill, crappie, gizzard shad and other fish species (Table 1). Some of these die-offs reportedly involved large numbers of fish. VHS virus has been isolated and confirmed from these die-offs. VHS has also been detected in samples of walleye, white bass, and silver redhorses and shorthead redhorse suckers that were not part of a die-off and were not symptomatic. It is not known how VHS virus was transferred to the Great Lakes , or how long it has been in the ecosystem; however, one possible scenario is that the virus may have mutated from a marine form and become newly pathogenic to naïve freshwater fish species. (full read here)
