Population Status of Lake Sturgeon in the Muskegon River, Michigan
Location
Hager-Lubbers Exhibition Hall
Description
The Muskegon River is a Lake Michigan tributary that supports a remnant population of lake sturgeon (Acipenser fulvescens), but the status of this population remains largely unknown. The purpose of this work was to assess the status of this population since 2008. Each spring, adult lake sturgeon were sampled by gill netting in Muskegon Lake and boat electrofishing in the Muskegon River. Juvenile lake sturgeon were sampled with gill nets at fixed sites in Muskegon Lake each fall. In fall 2013, we implemented stratified-random sampling in addition to fixed-site sampling to assess the effectiveness of our sampling design. We captured 108 unique adult lake sturgeon (range = 103.5 – 191.0 mm total length [TL]) during this study; captures ranged from 8 to 31 adults in any given year. Juvenile lake sturgeon were captured each year of the study (n = 165; range = 23.1 to 98.5 cm TL), but age analysis shows only two strong year classes (2007, 2009) truncated by several weak year classes. Age determination of lake sturgeon (n = 181) indicated 27 year classes were represented in our catch (mean age = 7.2). We captured significantly more (t10 = 4.078 P = 0.002) lake sturgeon at the fixed location than random locations in Muskegon Lake during fall 2013. Our results suggest spawning runs in the Muskegon River are small, survival of juveniles is highly variable, and fall gill netting at one highly occupied spatial area (i.e., fixed-site sampling) appears to be mostly effective.
Population Status of Lake Sturgeon in the Muskegon River, Michigan
Hager-Lubbers Exhibition Hall
The Muskegon River is a Lake Michigan tributary that supports a remnant population of lake sturgeon (Acipenser fulvescens), but the status of this population remains largely unknown. The purpose of this work was to assess the status of this population since 2008. Each spring, adult lake sturgeon were sampled by gill netting in Muskegon Lake and boat electrofishing in the Muskegon River. Juvenile lake sturgeon were sampled with gill nets at fixed sites in Muskegon Lake each fall. In fall 2013, we implemented stratified-random sampling in addition to fixed-site sampling to assess the effectiveness of our sampling design. We captured 108 unique adult lake sturgeon (range = 103.5 – 191.0 mm total length [TL]) during this study; captures ranged from 8 to 31 adults in any given year. Juvenile lake sturgeon were captured each year of the study (n = 165; range = 23.1 to 98.5 cm TL), but age analysis shows only two strong year classes (2007, 2009) truncated by several weak year classes. Age determination of lake sturgeon (n = 181) indicated 27 year classes were represented in our catch (mean age = 7.2). We captured significantly more (t10 = 4.078 P = 0.002) lake sturgeon at the fixed location than random locations in Muskegon Lake during fall 2013. Our results suggest spawning runs in the Muskegon River are small, survival of juveniles is highly variable, and fall gill netting at one highly occupied spatial area (i.e., fixed-site sampling) appears to be mostly effective.