Muskellunge Management: Fifty Years of Cooperation Among Anglers, Scientists, and Fisheries Biologists
How Might Changing Fishery Practices and Climate Affect the Lake St. Clair Muskellunge Fishery?
Jason B. Smith, Mary Tate Bremigan, Daniel B. Hayes, and Michael V. Thomas
Abstract.—The current Lake St. Clair Great Lakes Muskellunge Esox masquinongy fishery is entirely self-sustaining and dominated by a catch-and-release ethic. Catch rates of Lake St. Clair Muskellunge are among the highest documented for this species, and angler catches of trophy Muskellunge are considered relatively commonplace. The proximity of Lake St. Clair to many potential new Muskellunge anglers, interest among some anglers in restoring a long-prohibited winter spear fishery, and warming temperatures associated with climate change pose potential threats to the quality of this fishery. We developed an age-structured equilibrium yield model to project the likely effects of altered size and harvest limits, increased angling effort, establishment of a winter spearing season, or warming temperatures on open-water angling catch rates of three size-classes of Lake St. Clair Muskellunge (all fish ≥ age 1, legal-sized fish > 107 cm, and trophy-sized fish > 127 cm). Our modeling indicated that changes in regulations in the Lake St. Clair Muskellunge fishery were unlikely to result in substantial changes to catch rates of Muskellunge of any size-class. Similarly, the current high rate of voluntary release would largely buffer catch rates of all size-classes of Lake St. Clair Muskellunge from increases in fishing effort. Our simulation of a winter spearing fishery indicated that only high levels of spearing effort and harvest would reduce open-water catch rates to a degree that would likely be objectionable to anglers. In contrast, the predicted catch rates of legal-and trophy-sized fish were highly sensitive to modeled reductions in growth. As such, the major threat to this trophy Muskellunge fishery appears largely outside the traditional toolbox of fisheries managers, hastening the need for development of resilient management and monitoring plans for this valuable fishery.