Western North Atlantic Coastal Morphotype Stocks STOCK DEFINITION AND GEOGRAPHIC RANGE Stock Structure of the Coastal Morphotype

• Other Authors: The Pennsylvania State University CiteSeerX Archives
• Format: Text
• Language: English
• Subjects: Long Island; North Atlantic
• Online Access: http://citeseerx.ist.psu.edu/viewdoc/summary?doi=10.1.1.174.5098; http://www.nefsc.noaa.gov/publications/tm/tm205/pdfs/173BottlenoseD.pdf

A. Latitudinal distribution and structure along the coast The coastal morphotype of bottlenose dolphin is continuously distributed along the Atlantic coast south of Long Island, around the Florida peninsula and along the Gulf of Mexico coast. Based on differences in mitochondrial DNA haplotype frequencies, nearshore animals in the northern Gulf of Mexico and the western North Atlantic represent separate stocks (Curry 1997; Duffield and Wells 2002). On the Atlantic coast, Scott et al. (1988) hypothesized a single coastal migratory stock ranging seasonally from as far north as Long Island, NY, to as far south as central Florida, citing stranding patterns during a high mortality event in 1987-88 and observed density patterns. More recent studies indicate that the single coastal migratory stock hypothesis is incorrect, and there is a complex mosaic of stocks (NMFS 2001; McLellan et al. 2003). Genetic analyses of samples from northern Florida, Georgia, central South Carolina (primarily the estuaries around Charleston), southern North Carolina, and coastal Virginia, using both mitochondrial DNA and nuclear microsatellite markers indicate that a significant amount of the overall genetic variation can be explained by differences between these areas (NMFS 2001). These results indicate a minimum of five stocks of coastal bottlenose dolphins along the US Atlantic coast and reject the null hypothesis of one homogeneous population. Photo-identification studies also support the existence of multiple stocks (NMFS 2001). A coastwide