There are two populations of Commerson's dolphins; the groups are separated by about 8500 km (Goodall et al, 1994). The northern limit of the South American population is the Rio Negro at 40 deg S. Commerson's dolphins are most common at the western South Atlantic along the eastern coast of South America from 41deg 30'S to 55deg S, at the Strait of La Maire (Goodall et al, 1988). The overall range in the South American region is along the Patagonian coast south to Cape Horn, east to central Strait of Magellan and the Falkland Islands. Several sightings have also been noted in Drake Passage and just north of the South Shetlands at 61deg 50'S 63deg 17'W (Goodall, 1994).

 

There is a disjunct population of Cephalorhynchus commersonii in the area of Kerguelen Island in the South Indian Ocean (Leatherwood and Reeves, 1983). The range extends from 48deg 30'S to 49deg 45'S. Commerson's dolphin is the only cetacean that can be called common in Kerguelen coastal waters (Goodall, 1994).

 

Biogeographic Regions: Indian Ocean; Indian Ocean :: Native; Atlantic Ocean; Atlantic Ocean :: Native