Habitat Research: Natural Muskellunge in Wisconsin, Factors Affecting Self-sustaining Populations

Objectives of this research project are to identify and describe life history characteristics of self-sustaining muskellunge populations and their macro- and micro-habitat requirements.

Background

Muskellunge natural reproduction has declined or ceased in many waters. Stocking is costly, and survival rates of stocked fish are often low. Also, such stocking may jeopardize genetic fitness of the local populations by introducing new allele combinations (i.e., genetic variation).

The decline of natural muskellunge reproductive success has been explained in several ways. Competition with northern pike for food resources and spawning grounds has been suggested when the species occur together. Other explanations include overharvest, quantity and size of food available to muskellunge fry, and water temperature and water level at the time of spawning. Predation of the muskellunge fry by other fish and invertebrates has also been suggested. Reproductive failure may also be the result of loss or alteration of spawning habitat.

Defining requirements for natural reproduction of muskellunge is important for effective management. This study will further define self-sustaining muskellunge populations and biological parameters for their perpetuity. Identifying sensitive areas will help protect critical habitat. Quantifying watershed characteristics holds promise in identifying land use practices not compatible with successful muskellunge reproduction. Such information may prove useful to management programs addressing issues pertaining to shoreline development or nonpoint pollution sources.