Assessment of Population Characteristics and Genetic Origin of Muskellunge in a Section of the Mississippi River, Minnesota

摘要

Minnesota actively manages Muskellunge Esox masquinongy in 90 waters throughout the state. The vast majority of angling effort and subsequent assessments of these fisheries is focused within 80 lentic systems while relatively little is known about populations within lotic systems. As part of a collaborative effort with local volunteer anglers, a population assessment was conducted for the first time in a section of the Mississippi River known to support a self-sustaining fishery. In an effort to establish a complementary fishery in the section of river upstream, Leech-strain Muskellunge fingerlings were stocked annually beginning in 2006 and downstream migration was suspected. To evaluate the Muskellunge population within the downstream reach, boatelectrofishing and trained volunteer anglers were used to sample fish. Fish were genetically assigned as stocked (Leech strain) or local (Mississippi) origin fish using microsatellite DNA analyses. Subsequently, estimates of adult Muskellunge abundance were generated across 3 years of study for both local and stocked fish using a multiple census mark-recapture method. Abundance averaged 191 individuals or 0.44 fish/ha over 3 years, of which approximately 80% were determined to be of local origin. Anglers contributed data from 115 individual captures while 92 captures were by electrofishing; electrofishing captured a wider range and smaller average size than angling. The average growth for recaptured individuals was 12 mm/year total length. Integratingdata collected by trained volunteer anglers expanded the temporal and spatial breath of the sampling while helping verify the local fishery was relatively stable and similar to Minnesota lake fisheries.