Muskellunge Management: Fifty Years of Cooperation Among Anglers, Scientists, and Fisheries Biologists

Die-Off of Muskellunge in the Upper St. Lawrence River Caused by Viral Hemorrhagic Septicemia, 2005-2008 [Extended Abstract]

John M. Casselman, Tom Lusk, John M. Farrell, and Colin Lake

doi: https://doi.org/10.47886/9781934874462.ch33

Since the mid-1980s, Muskellunge Esox masquinongy populations in most water bodies in the province of Ontario have been specifically managed for large trophy size. It was agreed among fishing organizations, Muskies Canada, and fisheries researchers and managers that the growth potential warranted this special type of management designation. Through increased size limits in the 1980s and again in the 1990s, based on growth potential, and voluntary catch and release of legal-sized fish by dedicated Muskellunge anglers, the size structure of some populations increased dramatically, most notably those in large water bodies and river systems. The Muskellunge population of the St. Lawrence River responded most notably to the resulting decrease in exploitation, and a world-class trophy population and fishery of very large Muskellunge was established.

However, in the spring of 2005, large numbers of very large dead and dying Muskellunge were observed and reported throughout the Thousand Islands section of the upper St. Lawrence River. This widespread die-off was of special concern since this international population and fishery were world class, highly valued, and carefully managed internationally to achieve exceptional size and quality. Considerable effort was put forth in 2005 and 2006 to locate and collect all dead and dying Muskellunge found floating or on shore (Figure 1).