Patterns of intra-estuarine movement of adult weakfish (Cynoscion regalis): evidence of site affinity at seasonal and diel scales


Turnure, Jason T., Kenneth W. Able, and Thomas M. Grothues
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Fine-scale movements of and use of habitat space by individual marine fishes can structure broader population dynamics, yet little is known about these traits. This lack of key information applies to the economically and ecologically important sciaenid weakfish (Cynoscion regalis), which is seasonally distributed in estuaries and coastal habitats along the Middle Atlantic Bight, where it feeds and spawns. We examined movements of adult weakfish in a southern New Jersey estuary using acoustic telemetry at both seasonal (n=29 fish) and diel (n=9 fish) scales. From June through November 2008, a majority of tagged and redetected weakfish (12 of 20; 60%) established areas of localized residency. Several fish made excursions of varying distances (1.0–5.9 km) from these regions before returning after 1–2 weeks. At the diel scale, most weakfish (7 of 9; 78%) resided as a local aggregation during the day and made nighttime excursions beginning around sundown (1930 hours). No fish were detected within 0.5 km of their area of localized daytime residency after 2230 hours. These findings are new evidence of the affinity of adult weakfish within specific localities across ecologically relevant timescales and offer further insight into the importance of estuaries in the life history of weakfish.