January 2016 – Report prepared by Steven J. Kerr for Muskies Canada Inc. and Ontario Ministry of Natural Resources and Forestry
The Muskellunge (Esox masquinongy) is known as a voracious apex predator. In instances where muskellunge are extending their range, either through intentional or inadvertent introduction and natural range extension, concerns have been identified about the potential negative impacts on resident fishes and aquatic biota. This review has been conducted to assemble information on muskellunge predatory habits and diet as well as interspecific competition with other species.
Muskellunge prey on a wide variety of organisms but prefer other fishes. Predation is based largely on whatever species in available at the preferred size. There is a considerable amount of evidence to indicate that Muskellunge prefer soft-rayed fishes and the availability of soft-rayed prey cound determine the degree of predation on other species.
Generally, there a few definitive studies to quantify impacts (if any) of Muskellunge on other fish species. There is very little evidence to indicate that Muskellunge have a significant negative impact on populations of other popular sport fish species including Walleye, Largemouth Bass and Smallmouth Bass. In fact, there are numerous instances where these fish species successfully co-habit the same waterbody. Since Muskellunge seldom occupy coldwater habitats, their interactions with coldwater fishes (i.e. salmonids and coregonids) are poorly understood. This is an area which requires future study.
Potential negative impacts of Muskellunge on other fish species are probably related to the size of waterbody and the composition of the resident fish community. Larger waterbodies and those waters having a diverse forage fish community seem to be relatively unaffected by the presence of Muskellunge. The presence/abundance of soft-rayed fish species likely reduces the predation on other resident fish species.
Other fish species can have negative impacts on the Muskellunge. Northern Pike are known to have a competitive advantage over Muskellunge where they coexist. Young Muskellunge are also subject to predation by other fishes including Largemouth Bass, Yellow Perch, Rock Bass and Walleye.
Based on this literature review several recommendations are offered. These are related to initiating more quantified studies to document impacts (if any) when Muskellunge are introduced or become established in new waters, utilizing new state-of-the-art techniques to determine diets and predatory-prey relationships amongst a broader range of fish community types (including salmonids and species at risk), and developing efforts to improve the public perception of Muskellunge.
The full report is available by clicking the link below.