Movement patterns of the round stingray Urobatis halleri(Cooper) near a thermal outfall

摘要: Fine-scale movements and site fidelity of round stingrays Urobatis halleri at Seal Beach California, U.S.A., were examined using acoustic telemetry. Actively tracked fish generally exhibited limited nearshore movement, with greater distances travelled night when the tide was ebbing than during day tides. Increases in stingray activity associated increases ambient temperature. Passively showed seasonal patterns their presence Beach. Males left autumn, returned following spring, remained area until autumn. Females spent far less time Beach, remaining for a few weeks June July. recorded more often warm waters San Gabriel River mouth (the location thermal outfall from an electric-generating station) adjacent beaches, returning to after periods absence. Anthropogenic effects resulting coastal development may have created environmental conditions (i.e. warmer water finer sediments) that influence stingrays.