Seasonal movements of reproducing winter flounder (Pseudopleuronectes americanus): connectivity between the ocean and estuary in the Middle Atlantic Bight

Abstract

Winter flounder ( Pseudopleuronectes americanus ) spawn demersal adhesive eggs in estuaries and on the continental shelf with patterns varying by climatic region. To identify habitat use and connectivity at the southern edge of their population during the spawning season, we telemetered adult winter flounder ingress, egress, and residence in and through the Barnegat Bay Estuarine Complex and adjacent coastal ocean. Some adults tagged in the ocean moved into the estuary in the winter of each year 2009 and 2010, while capture and tagging of individuals in late fall of the previous year indicated fall entry or residency. Ripeness and ocean residence suggest that some individuals may spawn in the ocean. Individuals utilizing the estuary occupied water of temperature as low as 0.5 °C and residency into August exposed individuals to temperature as high as 22.8 °C. Ingress to the estuary occurred all winter and spring into May in 2009, when all individuals caught were spent. Tagged individuals began estuarine egress in spring, with 43% of 17 winter 2009-tagged individuals that left doing so in April 2009, but egressing as late as July, and 100% of winter 2010-tagged individuals that left ( n = 9) doing so by April 2010, but starting earlier (March) than in 2010. Females tended towards warmer water occupancy but earlier egress than males. These findings can provide insights into the status of this declining population, especially relative to human activities such as dredging for estuarine channel maintenance, ocean beach nourishment, offshore wind development and climate change.

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