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Abstract
The lake sturgeon was once abundant throughout Lake Michigan with an estimated 11 million fish prior to human exploitation. By the early 1900s, however, most populations had been decimated by severe over-fishing and habitat degradation. Despite recent interests in restoring the species in Lake Michigan, little is known about the current status of remnant populations. The primary objectives of this study were to estimate annual spawning stock abundance and to identify potential spawning habitat for lake sturgeon on the Muskegon River, Michigan. To capture adult lake sturgeon, I used large-mesh, bottom-set gill nets deployed at the mouth of the Muskegon River from mid-March through May, 2002-2005. Radio telemetry was used to monitor seasonal movements and to identify likely spawning habitats. Sampling for larval lake sturgeon was conducted in May of each year using D-frame drift nets anchored in the mainstream of the river channel. During the 4 years of the study, I expended more than 5000 gill-net hours and captured 59 individual adult lake sturgeon. Larval lake sturgeon were captured in 2 years, suggesting that at least some natural reproduction still occurs. Habitat analysis revealed that the lower Muskegon River likely contains extensive reaches of potential spawning habitat for lake sturgeon.