STOCK DEFINITION AND GEOGRAPHIC RANGE

• Other Authors: The Pennsylvania State University CiteSeerX Archives
• Format: Text
• Language: English
• Published: 2005
• Subjects: Caldwell; Spotted Island; North Atlantic
• Online Access: http://citeseerx.ist.psu.edu/viewdoc/summary?doi=10.1.1.174.6088; http://www.nefsc.noaa.gov/publications/tm/tm201/pdfs/322-325.pdf

There are two species of spotted dolphin in the Atlantic Ocean, the Atlantic spotted dolphin (Stenella frontalis) and the pantropical spotted dolphin (S. attenuata) (Perrin et al. 1987). The Atlantic spotted dolphin occurs in two forms which may be distinct sub-species (Perrin et al. 1987, 1994; Rice 1998): the large, heavily spotted form which inhabits the continental shelf and is usually found inside or near the 200m isobath; and the smaller, less spotted island and offshore form which occurs in the Atlantic Ocean but is not known to occur in the Gulf of Mexico (Fulling et al. 2003; Mullin and Fulling 2003; Mullin and Fulling 2004). Where they co-occur, the offshore form of the Atlantic spotted dolphin and the pantropical spotted dolphin can be difficult to differentiate at sea. The Atlantic spotted dolphin is endemic to the Atlantic Ocean in temperate to tropical waters (Perrin et al. 1987, 1994). In the Gulf of Mexico, Atlantic spotted dolphins occur primarily from continental shelf waters 10-200m deep to slope waters <500m deep (Fulling et al. 2003; Mullin and Fulling 2004). Atlantic spotted dolphins were seen in all seasons during GulfCet aerial surveys of the northern Gulf of Mexico from 1992 to 1998 (Hansen et al. 1996; Mullin and Hoggard 2003). It has been suggested that this species may move inshore seasonally during spring, but data supporting this hypothesis are limited (Caldwell and Caldwell 1966; Fritts et al. 1983). In a recent study, Bero (2001) presented strong genetic support for differentiation between Gulf of Mexico and western North Atlantic management stocks using both mitochondrial and nuclear markers. However, this study did not