Larval trapping is conducted in the spring and is used to detect the presence or absence of egressing larval northern pike and/or other species originating in Program tributaries. The WDNR has used larval traps to successfully detect larval northern pike in Lake Michigan tributaries near Green Bay, WI. As such, the method was adopted and added to the ecological monitoring program subsequent to work plan development and finalization.
Two types of traps are used in our surveys, box traps and quatrifoils. Quatrifoil traps require a glow stick and are utilized in areas that have little to no stream flow.
Like visual surveys, larval trap netting filled a critical gap in the Program’s ecological monitoring and provided a reliable, consistent method for detecting northern pike spawning in Program tributaries.
Fyke nets were deployed in Program tributaries between April 8 and April 23, 2010 (i.e., shortly after spring thaw, immediately upon equipment receipt, and prior to impediment removals) to document the presence or absence of adult northern pike and other migratory fish species during the typical northern pike spawning season.