Seasonal Movement and Mesohabitat Usage of Adult and Juvenile Lake Sturgeon in the Grasse River, New York

Long‐term restoration efforts for lake sturgeon Acipenser fulvescens populations will benefit from better understanding of this species’ movements and habitat use in riverine systems. Radio transmitters were implanted in both juvenile and adult lake sturgeon in the Grasse River, New York, and individuals were relocated over a 2‐year period. Adult lake sturgeon demonstrated greater minimum daily distance moved, absolute distance moved, and mean home range size than juvenile lake sturgeon during the spring. During the course of the study, both adult and juvenile lake sturgeon exhibited movements upstream and downstream through a breached low‐head weir, and individuals did not necessarily remain resident on an annual basis in the Grasse River. Mesohabitat and substrate use patterns were determined based on comparisons of frequency distributions for relocated lake sturgeon and quantified mesohabitat and substrate over a 15‐km river reach. Lake sturgeon used pool mesohabitat and limited their use of run mesohabitat under both low‐ and mid‐flow conditions. During most of the year, adult and juvenile lake sturgeon were detected over silt substrate. This study illustrates behavioral differences and similarities between the movements and habitat use of adult and juvenile lake sturgeon in a riverine system.