Humpbacks inhabit all major oceans, in a wide band running from the Antarctic ice edge to 81°N latitude. The four global populations are North Pacific, Atlantic, Southern Ocean and Indian Ocean populations. These populations are distinct. Although the species has cosmopolitan distribution and is usually not considered to cross the equator line, seasonal observations at Cape Verde suggest possible interactions among populations from both hemispheres. Aside from the Arabian Sea group, year-round presences have been confirmed among British and Norwegian waters. Parts of wintering grounds around the globe have been poorly studied or being undetected, such as around Pitcairn Islands, Northern Mariana Islands (e.g. Marpi and CK Reefs vicinity to Saipan), Volcano Islands, Pasaleng Bay, Trindade and Martin Vaz, Mauritius, and Aldabra.