MEPS prepress abstract  -  doi: 10.3354/meps07391

ABSTRACT: A comprehensive understanding of habitat use for economically and ecologically important species in estuaries is lacking. This research, based on passive and active ultrasonic telemetry, focuses on temporal and spatial patterns of juvenile and adult (total length = 268–535 mm range) summer flounder, Paralichthys dentatus, habitat use during years, seasons, tides, and diel periods, from 2003–2005, in the Mullica River-Great Bay estuary in southern New Jersey. Annual site fidelity was demonstrated by tagged fish that returned to the study estuary and frequented locales within 550 m or less of the sites where they were located in previous year(s). Fish resided within the estuary for a mean of 86 days (range: 1–217 days) during summer 2004, the year of the most comprehensive tracking. Fish primarily utilized the lower bay close to the ocean inlet. Several more mobile individuals moved along the channel of the Intracoastal Waterway numerous times in a single season, while others moved up the bay and into the river in a year when salinity was higher than average. Tagged fish typically used deeper areas of the estuary correlated with high, stable levels of dissolved oxygen and temperature. Over diel and tidal periods, fish resided within small (0.18 km²) areas for 3 – 6 hours but were in motion 74% of that time. Together, these observations indicate habitat use patterns that are stable over long periods (years) but dynamic within shorter time periods (seasons, hours).