Analysis of a Long-Term Dataset to Determine Habitat Use and Spatial Variability of Species during Overwintering in Near-Shore Waters

The Cooperative Winter Tagging Cruise is representative of a long-term (1988-2013), fishery-independent dataset. This project analyzed the dataset for spatiotemporal patterns in habitat use and distribution, and to determine associating factors influencing the presence and absence of striped bass (Morone saxatilis), spiny dogfish sharks (Squalas acanthias), the endangered Atlantic sturgeon (Acipenser oxyrinchus oxyrinchus), summer flounder (Paralichthys dentatus), and members of the Clupeidae family (Alosa sapidissima, Alosa psuedoharengus, and Alosa aestivalis) in overwintering grounds within the shelf waters of North Carolina and Virginia. ArcGIS 10.1 was used to create maps of the CWTC trawl locations and catches, derived from the bridge and deck logs from each year. Habitat information not recorded during the trawling effort was obtained from the USGS usSEABED Atlantic Data files and layers were generated by kriging (encompassing depth and percent organic carbon) and Theissen polygons (encompassing sediment type). Habitat parameters also included were water temperature, time of day, and tidal stage. Overlaying the habitat layers generated with catch data allowed for the characterization of habitat types. Descriptive statistics allowed for the characterization of trawl captures and habitat types, and spatial analysis revealed patterns seen over time in the distribution of the species.