Response of fish sound production to short‐term ocean upwelling events at the LEO‐15 (Long‐term Ecosystem Observatory at 15 m depth) ocean observatory.

Abstract

Understanding factors controlling the distribution and reproduction of fishes is crucial for developing ecosystem models of fish populations. Yet these observations are difficult to make on physically relevant time and space scales. A hydrophone was used to record fish sound production associated with reproduction at the LEO‐15 ocean observatory to determine the relationship between variation in fish calling behavior and oceanographic variation. Sound production was dominated by Atlantic croaker (Micropogonias undulatus), weakfish (Cynoscion regalis), and striped cusk‐eel (Ophidion marginatum). Striped cusk‐eels called with a crepuscular pattern, with a strong peak at dusk, less sound production during the night, and a lesser peak in sound production at dawn. Sciaenids called mostly at dusk and night. Nine advection events bringing colder waters to the LEO‐15 site were correlated with greatly reduced levels of sound production in Atlantic croaker and weakfish on daily time scales. Our results show how ocean observatories with passive acoustics can study tightly coupled physical oceanographic influences on fish behavior on daily time scales.