Spring Capture Site Fidelity of Adult Muskellunge in Inland Lakes

Behaviors that affect the distribution of fish within aquatic systems are important considerations in the design of sampling programs. Although movements consistent with reproductive homing have been documented for muskellunge Esox masquinongy in relatively large, complex systems, quantitative data describing their distribution at the restricted spatial scale relevant to small lake fisheries are lacking. We sampled muskellunge by means of fyke netting over 2 years in each of four Wisconsin lakes with surface areas between 110 and 588 ha. Individual capture locations were recorded. Each muskellunge sampled during the first year was injected with a passive integrated transponder to allow identification of the individuals recaptured during the second year. The number of recaptures with functional transponders during the second year ranged from 15 to 43 per lake. Capture site fidelity, defined as the percentage of recaptured fish being found in the same spawning area in two consecutive years, varied from 55% to 93%. The results are relevant to population estimation and broodstock collection for artificial propagation. Population estimates need to include all spawning habitats because marked and unmarked fish are not well mixed throughout the lake during the spawning season. Because repeated netting effort at the same locations among years is likely to resample individuals used for broodstock collection, netting effort should be dispersed among spawning sites. Received October 21, 2010; accepted February 18, 2011