Long-finned pilot whales occur in temperate and subpolar zones (Olson and Reilly 2002). They are found in oceanic waters and some coastal waters of the North Atlantic Ocean, including the Mediterranean Sea and North Sea. In the North Atlantic, the species occurs in deep offshore waters, including those inside the western Mediterranean Sea (where it is thought to be the only species of pilot whale found), North Sea, and Gulf of St. Lawrence (Abend and Smith 1999). Long-finned pilot whales were previously found in the western North Pacific as well but appear to be absent there today. The circum-Antarctic subpopulation(s) in the Southern Hemisphere occur as far south as the Antarctic Convergence, sometimes to 68°S. They are apparently isolated from those of the Northern Hemisphere (Bernard and Reilly 1999).