Three-dimensional Habitat Occupancy of Wild Juvenile and Stocked Adult Lake Trout in Lake Champlain
February 1, 2020 to January 31, 2022
Lake trout are a native cold-water species and a top predator in Lake Champlain. The species was extirpated from Lake Champlain by 1900 but reintroduced in the early 1970s through stocking. Despite decades of stocking, establishment of a self-sustaining population has remained an elusive goal.
Lake trout eggs and fry have been sampled in high densities at several sites throughout the Main Lake, but limited sampling occurred for juveniles prior to 2015 and no wild lake trout were collected. Fish survival after the first winter of life is generally high, and lake trout stocked in fall at age-0 (at the size of wild age-1 lake trout) reach maturity and maintain the current lake trout fishery. Therefore, there appears to be a bottleneck between June, when wild young-of-year (YOY) individuals leave spawning reefs, and survival to age-1.
Researchers will examine factors that affect early survival, recruitment, and behavior of wild juvenile and adult lake trout that may be critical for establishment of a self-sustaining population in Lake Champlain. Researchers will surgically implant wild and stocked lake trout with acoustic telemetry tags. The data obtained will include the spatial location of tagged individuals for two successive spawning years in the central basin of the Main Lake and will provide insight into important spawning grounds for both stocked and wild fish as well as a three-dimensional (latitude, longitude, and depth) representation of year-round habitat selection.