Genetic analysis of sub-adult Atlantic sturgeon in the mid-Atlantic bight

The Atlantic sturgeon (Acipenser oxyrinchus) is currently a candidate for listing under the U.S. Endangered Species Act.  While recent genetic work has focused on identifying distinct population segment (DPS) units within spawning rivers, very little work has been done to understand the relative contribution of these DPS units to sturgeon living in the near-shore marine environment in different geographic regions.  Elucidating the distribution and movements of sub-adult fish is especially important because protecting this highly vagile demographic is critical in order to sustain recruitment.  From 2005-2009, we collected tissue samples from ~500 sub-adults captured along the Mid-Atlantic Bight and used mitochondrial control region DNA sequences to estimate the relative contribution of different DPS units to these fish. Our objectives are to (1) delineate the natal-origins of sub-adult fish utilizing specific aggregation areas in the Mid-Atlantic Bight, (2) elucidate any seasonal patterns and (3) determine whether the contribution of different DPS units has changed over the past two decades .These analyses will provide vital information to managers, relaying which Atlantic sturgeon DPS units are most vulnerable to incidental mortality of sub-adults within this especially heavily-fished region.