Evaluation of sampling techniques for ago-0 juvenile lake sturgeon in the lower Peshtigo River, Wisconsin, and nearshore waters of Green Bay
juvenile, lake sturgeon, sturgeon, Great Lakes, active, survey, Fyke nets, night
Journal or Book Title
North American Journal of Fisheries Management
Rehabilitation of lake sturgeon (Acipenser fulvescens) in the Great Lakes would benefitfrom a greater understanding of early life stage attributes. The objectives of this study were todetermine the efficacy of active and passive sampling gears for capturing age-0 lake sturgeonand evaluate whether the most effective gear types were size selective. Fish were collected bymeans of active (i.e., wading, haul-seine, backpack electrofishing, snorkelling surveys, andbottom trawls) and passive (i.e., gill nets, set lines, and fyke nets) sampling gears from June toNovember of 2002 and 2003 in the lower Peshtigo River, Wisconsin, and nearshore waters ofGreen Bay. Mean catch per unit effort (CPUE) was greatest for day wading (0.036 fish/min),followed by day haulseine surveys (0.029 fish/min), night wading (0.020 fish/min), and night haulseine surveys (0.015 fish/min). Night wading surveys captured the greatest number of fish (N 5118). Day and night electrofishing (CPUE 5 0.008 and 0.013 fish/min, respectively), snorkelling(CPUE 5 0.010 fish/min), and gill nets (CPUE 5 0.026 fish/d) were less effective gear types, whilebottom trawls, set lines, and fyke nets did not capture fish. Smaller fish were captured during daywading and haulseine surveys (median 5 71 and 68 mm, respectively) than during night wadingand haul-seine surveys (median 5 120 and 133 mm, respectively). Based on these results, werecommend the use of wading and haul-seine surveys to collect age-0 lake sturgeon in shallowlotic and lentic systems, such as the lower Peshtigo River and Green Bay, that are characterizedby low current velocity and high water clarity.