Spawning lake sturgeon (Acipenser fulvescens Rafinesque, 1817) and their habitat characteristics in Rainy River, Ontario and Minnesota

摘要: Summary Lake Sturgeon (Acipenser fulvescens) spawning habitat in the Rainy River was studied light of ongoing review rules governing water levels upstream that affect discharge rates through International Falls dam. The objectives this study were to assess current status Lake below dam by: (i) evaluating weight–length relationships, condition, age and growth; (ii) identifying locations characterizing its physical attributes; and, (iii) effects surface elevation on availability habitat. Spawning confirmed with use egg mats, targeted sampling individuals completed using gillnets electrofishing. Physical attributes locations, including temperature, depth velocity collected at a range an Acoustic Doppler Current Profiler representative sediment sampling. Biological characteristics timing events consistent those previously reported for Sturgeon. However, wider depths (0.3–10.5 m) velocities (0.01–1.9 m3/s) than most single site studies found here, ranges encompassing what is literature as whole. prefer coarse substrates dominated by bedrock, boulder or cobble. preferred varied significantly changing observed during eventually limited higher river channel form. Because implications dewatering nest sites, keeping flows constant critical success.