Determination of Dispersal Patterns and Characterization of Important Habitats for Lake Sturgeon Restoration in The Upper Tennessee River System

Lake Sturgeon, Acipenser fulvescens, are one of the slowest to reach sexual maturity and longest-lived freshwater fish species in North America. These fish are a species of special concern by the U.S. Fish and Wildlife Service, a vulnerable species by the American Fisheries Society (Jelks et al. 2008), and a threatened species in Tennessee (Chiasson et al. 1997; Williams et al. 1989). They have been reintroduced into the Upper Tennessee River system since 2000.

Since December 2013, 49 Lake Sturgeon have been implanted with ultrasonic acoustic transmitters, and 26 fixed-station receivers installed throughout the Upper Tennessee River System to monitor their movement. The objectives of this study were: 1) to determine dispersal and movement patterns of reintroduced Lake Sturgeon in the Upper Tennessee River system, 2) to identify water quality characteristics of seasonally important habitats, 3) to compare temperature and dissolved oxygen at summer refugia areas of known sturgeon concentrations, with other unused habitats, 4) to identify and assess potential spawning habitats in the Upper Tennessee River system, and 5) to determine if dams inhibit upstream and downstream movements.

Lake Sturgeon implanted with acoustic transmitters were detected and monitored throughout the study area in the Upper Tennessee (RM 427-632), Clinch (RM 0-5), Hiwassee (RM 5-501.9), Holston (RM 0-52.2), and French Broad Rivers (RM 0-32.3). There was a higher concentration of fish aggregating in Fort Loudoun Reservoir and smaller numbers in Watts Bar and Chickamauga Reservoirs. Movements varied with the majority of the fish traveling(>2 fish) were designated as “core use”. During the study, there were 1,130,809 individual transmitter detections recorded.

The temperatures and dissolved oxygen (DO) levels recorded fell within acceptable ranges for Lake Sturgeon with the exception of the summer season in Chickamauga Reservoir. Temperatures rose to >30 C and the DO levels dropped to/L June through August 2014. Gaining a better understanding of the factors affecting Lake Sturgeon recruitment and survival will be critical in designing restoration or reintroduction programs in the upper Tennessee River system and areas like it.