Speaker: Charles Bangley (SERC postdoctoral fellow)

Summary: Estuaries function as important nursery and foraging habitat for many coastal species, including highly migratory sharks. Pamlico Sound, North Carolina, is one of the largest estuaries in the continental United States and is situated at a break between major marine biogeographic regions, creating a variety of potential habitats for sharks. In order to identify and spatially delineate shark habitat within Pamlico Sound, shark catch and environmental data from the 2007-2014 North Carolina Division of Marine Fisheries gillnet and longline surveys within the estuary were analyzed. Principal species in the Pamlico Sound shark assemblage were identified, and environmental data recorded at survey sites (depth, temperature, salinity, dissolved oxygen, SAV distance, and inlet distance) were interpolated across Pamlico Sound to create seasonal environmental grids with a 90-m² cell size. Boosted regression tree analysis was used to identify the most important environmental factors and ranges associated with presence and abundance of each principal species, and the resulting models were used to predict shark abundance based on the values within the environmental grid cells.  Temperature had a strong effect on the presence of all principal shark species in Pamlico Sound, while salinity was an important environmental factor affecting abundance within the estuary.  Species-specific abundance predictions showed potential associations with particular geographic features and habitat types.  Pamlico Sound hosts a diverse assemblage of sharks, and these predators are likely an important component of the estuarine community.