Availability of Northern Pike Breeding Habitat in Rainy Lake and Namakan Reservoir, Minnesota

This study investigates effects of water level changes due to International Joint Commission rule curves on northern pike breeding habitat in Rainy Lake and Namakan Reservoir, Minnesota. The main objective is to compare predicted northern pike spawning and nursery habitat, using water level, temperature, and aquatic macrophyte Arc GIS data to field data to verify larval and young-of-the-year (YOY) habitat use.  A second objective is to compare sampling efficiency of electrofishing, trap netting, and seining for YOY to determine the most effective method.  This study will expand larval light trapping, YOY sampling, and aquatic plant stem density sampling within Rainy Lake and Namakan Reservoir to identify specific characteristics for highly productive breeding habitat.  Light trapping data from Dove Bay and Sullivan Bay, 2011 suggests that high breeding success is associated with mean water levels ≥ 337.4 meters in Dove Bay and ≥ 340.5 meters in Sullivan Bay.  Preliminary comparisons of seining and trap netting data for YOY sampling suggests that trap netting is the most effective method, with 1.25 mean YOY per seine haul (121 YOY per 92 seine hauls from 1969-1986) and 2.5 mean YOY per trap net (75 YOY per 30 trap nets from 2011).