Monitoring Lake Sturgeon Behavior Patterns Using Radio-Telemetry

A critical need associated with sturgeon rehabilitation is to have a better understanding of post-stocking behavior and movement of fish as a function of age, season (temperature), habitat, food and strains.  Fingerlings, yearlings and juvenile lake sturgeon from the Lake Winnebago system were stocked in May, June, August, November and December.  Captive and wild lake sturgeon fingerlings, yearlings and juveniles were surgically implanted with radio transmitters, 1.0 g to 25g.  Radio telemetry tracking was conducted 8-10 hours per day for the first 3 weeks.  Subsequent tracking was bi-weekly using piloted aircraft.  Most river releases resulted in rapid distribution and movement downstream during May-August.  The movement response for November-December for all ages exhibited slow distribution and limited movement downstream.  Some fish remained in the river system and exhibited seasonal movement.  The behavior of sturgeon released into lake systems exhibited more diverse movement patterns.  Fish captured several years after stocking showed a tendency to be more limited in their movement especially in lake systems.  Although lake sturgeon movement was the most common behavior exhibited, stationary patterns were displayed by some of the fish.  These fixed patterns would exist for 7-10 months.  We believe this non-activity was related to habitat and/or food.