Growth and Size-Selective Mortality of Stocked Muskellunge: Effects on SizeDistributions

摘要

Sport fisheries for muskellunge Esox masquinongy are often sustained by stocking.Size-selective mortality has been identified as an important factor affecting stocked muskellunge. However, this mortality is difficult to assess because its effects on the population can be confounded by growth. To partition observed shifts in length frequencies of stocked muskellunge into growth and mortality effects, two lots each of approximately 1,000 hatchery-reared muskellunge fingerlings were sorted into 10-mm size-groups, marked with size-specific fin clips, and stocked into two northwestern Wisconsin lakes. Beginning 30 d after stocking, the authors used electrofishing to examine length distributions and estimate abundance of stocked fish.