28th ANNUAL EASTERN FISH HEALTH WORKSHOP April 21-25, 2003 Recent Fish Health Issues in New York State’s Great Lakes Waters John H. Schachte New York State Department of Environmental Conservation, Fish Disease                   Control Unit, 8314 Fish Hatchery Road, Rome, NY 13440 During the period from 2000 to 2002 we have detected an increase in the appearance of certain health anomalies and systemic infection in several species of wild and free ranging species in New York’s Great Lakes waters of Lake Ontario and Lake Erie. In Lake Ontario, adult returning chinook salmon (Onchorynchus tshawytscha) have begun to exhibit an increasing incidence of nephrocalcinosis in the kidney. A new condition also began to appear in angler caught adult chinook presented at various fish cleaning stations along the Lake Ontario shoreline. This anomaly, with the gross appearance of a fluid filled cyst, has been tentatively associated with the presence of a slow pigmenting isolate of the bacterium, Aeromonas salmonicida. No systemic infection has been detected in such fish. We have also observed limited adult steelhead trout (Onchorynchus mykiss) with a dermal infection of A. salmonicida with no accompanying systemic infection. Finally in Lake Ontario chinook, and to some extent coho salmon (Onchorynchus kisutch) and steelhead, we continue to see an asymptomatic A. salmonicida systemic infection rate of approximately 10% in fish sampled at spawning. In Lake Erie walleye (Stizostedion vitreum), submissions of adult angler caught walleye, display signs of myofibrogranuloma. During the summer of 2002, an increasing number of such walleye were reported. Return to 28th Annual Eastern Fish Health Workshop Return to Leetown Science Center Home Page