Movement and habitat of juvenile lake sturgeon (Acipenser fulvescens) in the Sturgeon River/Portage Lake system, Michigan

The Portage Lake/Sturgeon River system in Michigan contains one of the last self-sustaining stocks of lake sturgeon (Acipenser fulvescens) in the Great Lakes without barriers to impede natural movement of juveniles. We conducted visual surveys in the Sturgeon River and collected young-of-the-year and juvenile lake sturgeon from 1997 to 2000. Twenty-four fish, 9.8 to 28.8 cm total length (TL), were found predominately over pea gravel 16 to 26 km below the spawning site. With gillnets and trotline we collected an additional 24 fish (22–83 cm TL) and one sub-adult (103.5 cm TL) lake sturgeon in Portage Lake; four juveniles and the sub-adult were fitted with radio transmitters. Average daily linear movement of lake sturgeon varied from 0.3 to 1.6 km. Total linear distance traveled by sturgeon averaged 15.5 km over 83 days. Diel movements indicated that two juveniles moved into shallow ( \u3c 5 m) inshore areas at night and into deeper (\u3e 7.5 m) offshore areas as light intensified. © 2004, Copyright Taylor & Francis Group, LLC

Abiotic habitat assessment for arctic grayling in a portion of the big Manistee river, Michigan

© American Fisheries Society 2017. Arctic Grayling Thymallus arcticus were once the dominant salmonid in the Big Manistee River, Michigan, but were extirpated from the watershed around 1900 and from the state of Michigan by 1936, likely due to overfishing, biotic interactions with introduced fish species, and habitat loss occurring largely around the turn of the 20th century. An interest in reestablishing native species by the Little River Band of Ottawa Indians led to an assessment of environmental conditions in a portion of the watershed encompassing 21 km of the Big Manistee River to determine whether suitable Arctic Grayling habitat remains. During summer in 2011–2013, abiotic habitat metrics, including water characteristics, substrate composition, channel profile, channel geomorphic unit, and stream velocity, were assessed across eight tributaries within the watershed. To assess whether abiotic conditions in these tributaries might support Arctic Grayling, the environmental conditions were compared to literature values from rivers where current or historical Arctic Grayling populations have been reported. This comparison, in conjunction with an assessment using a habitat suitability index for Arctic Grayling, indicated that important abiotic conditions were within ranges consistent with those associated with current and past populations of Arctic Grayling in North America. The results of this study will guide potential future reintroductions and indicate that suitable Arctic Grayling habitat does exist in portions of the Big Manistee Rive