Habitat associations and dispersal of black sea bass from a mid-Atlantic Bight reef

Abstract

We examined habitat associations of 122 adult black sea bass Centropristis striata at a temperate reef off the coast of New Jersey, USA. The study site, located within the Historic Area Remediation Site, encompassed 46.1 km 2 and included areas of rocky bottom and highly variable bathymetry. Factors influencing dispersal and habitat use were determined from acoustic tele - metry data collected between May and December 2003 from a grid of 72 moored receivers. About 2.7 times as many black sea bass used the site in summer as in fall. Fish were associated with rel- atively shallow, complex habitats characterized by previously placed, coarse-grain material that may have provided food, shelter, or both. Deep areas (>27.5 m) with coarse-grain material were rarely used. Dispersal of black sea bass was not a pulse event, but rather a steady movement of individuals away from the site as inshore bottom water temperatures declined between late Sep- tember and mid-December. Both temperature and photoperiod may serve as cues to the initiation of offshore movements of fish to wintering grounds near the edge of the shelf. Some black sea bass resided at the reef for periods of up to 6 mo encompassing the spawning period; as such, these habitats may be important to the continued production of the stock. In the mid-Atlantic Bight, sur- veys to estimate the relative abundance of this species during their inshore residency period should be conducted in July-August in structurally complex habitats and in waters <28 m deep.