Adult Pacific Lamprey Migration Behavior and Escapement in the Bonneville Reservoir and Lower Columbia River Monitored Using the Juvenile Salmonid Acoustic Telemetry System (JSATS), 2011

Abstract

Abstract : In 2011, we continued our evaluation of the Juvenile Salmon Acoustic Telemetry System (JSATS) for monitoring the migration and final fates of adult Pacific lampreys in Bonneville Reservoir and the Bonneville Dam tailrace, two areas with high unaccounted loss in past telemetry studies. We tagged adult Pacific lamprey (Entosphenus tridentatus) with Juvenile Salmon Acoustic Telemetry System (JSATS) tags and half-duplex (HD) PIT tags and monitored their upstream passage and migration behaviors. Our objectives were to calculate lamprey travel times, to estimate escapement past the monitored sites, and to evaluate JSATS detection efficiency. We tagged 85 adult Pacific lamprey collected at Bonneville Dam with both JSATS and HDPIT transmitters from 11 June through 3 September. We used two types of JSATS transmitters: a 60 day battery life type and a 400 day battery life type. All fish were trapped and tagged at the Adult Fish Facility at Bonneville Dam and were released at either the Hamilton Island boat ramp (rkm 232) in the Bonneville Dam tailrace or the Stevenson boat ramp (rkm 242.7) in Bonneville Reservoir. We deployed 16 JSATS autonomous receivers between Bonneville and The Dalles Dam tailraces, including one in the Klickitat River 300 m from the mouth. Receivers were deployed singly or in pairs as detection gates allowing us to calculate travel times and determine distribution and final fates for multiple reaches within Bonneville Reservoir. Estimated detection efficiencies for most of our acoustic receiver gates were 85% or greater, and release site receiver efficiencies ranged from 50% in the Bonneville Dam tailrace to 97% at Stevenson. The escapement estimate for lampreys released into the Bonneville Dam tailrace past the dam was 35%, lower than estimates from previous HD-PIT studies (41-53%).