Ultrasonic Telemetry of Age-0 Summer Flounder, Paralichthys dentatus, Movements in a Southern New Jersey Estuary

Abstract

estuary. We captured, tagged, and released nine fish (210-254 mm TL) in a 1.2 km subtidal creek. We used stationary and mobile hydrophone systems to monitor fish movements for a cumulative total of 131 days and 1567 locations of individual fish during Aug. and Sept. 1990. Four fish immediately migrated down the creek, stopped at the creek mouth, did not return up the creek, and left the creek mouth within five days. The other five fish also initially moved down the creek and stopped at the mouth but subsequently migrated up and down the creek over periods of eight to 33 days. We estimated an average creek residence of 14 days for all fish. Between high and low tides, fish moved mostly in the same direction as the tidal current (57%), stayed in the same place (34%), and occasionally moved against the tide (9%). We detected significant (P _ 0.05) tide height, diel periodicity, and tide-diel interaction effects on fish position in the creek. Though fish were found in a wide range of temperatures, salinities, and dissolved oxygen concentrations, they generally stayed within narrow limits of these parameters as indicated by similar means and small standard deviations for these parameters. All tagged fish moved out of the creek by Oct., presumably as part of a seasonal migration of age-0 P. dentatus into the Atlantic Ocean. Because several age-0 P. dentatus used the creek for long periods during a time of fast growth, the present data supports earlier studies suggesting that subtidal creeks are important nurseries for this species.