The 2020 biennial Commission meeting of the IWC will be held at the Grand Bernardin Resort, Portoroz, Slovenia
The 2021 meeting of the IWC Scientific Committee will be held in Bled, Slovenia
Common dolphins are, as the name suggests, widely distributed throughout tropical and temperate waters, and can be found in both nearshore and offshore environments. They are easily recognizable by their striking hourglass or criss-cross pattern that includes a yellowish or tan patch, when almost all other dolphins are limited to shades of black, white and grey. For a time common dolphins were divided into two species – short-beaked common dolphins (Delphinus delphis) and long-beaked common dolphins (D. capensis). However, in 2015 genetic studies determined that all populations examined to date would be more logically grouped under one species (D. delphis) with four recognized subspecies of common dolphins throughout the species’ range: The common dolphin (D. d. delphis); Eastern North Pacific long-beaked common dolphin (D. d. bairdii ); the Black Sea common dolphin ( D. d. ponticus ); and the Indo-Pacific common dolphin ( D. d. tropicalis).1,2 Common dolphins can occur in nearshore or offshore environments, and while they are regularly seen in some areas, in others they are observed only as an added bonus to whale or dolphin watching tours that are focused on more predictable species.
Common dolphins are found in warm temperate and tropical waters around the world ranging from approximate latitudes between 50°S and 50°N3,4. They are found both in deep open ocean waters and nearshore habitats.
Common dolphins are native to the following countries**: Albania; Algeria; Argentina; Australia; Belgium; Bosnia and Herzegovina; Brazil; Bulgaria; Canada; Chile; China; Colombia; Costa Rica; Croatia; Cyprus; Denmark; Ecuador; Egypt; El Salvador; France; Gabon; Gambia; Georgia; Germany; Gibraltar; Greece; Guatemala; Guinea; Guinea-Bissau; Honduras; Ireland; Israel; Italy; Japan; Korea, Democratic People's Republic of; Korea, Republic of; Lebanon; Libya; Malta; Mauritania; Mexico; Monaco; Montenegro; Morocco; Namibia; Netherlands; New Caledonia; New Zealand; Nicaragua; Norway; Palestinian Territory, Occupied; Panama; Peru; Poland; Portugal; Romania; Russian Federation; Saint Barthélemy; Senegal; Slovenia; South Africa; Spain; Syrian Arab Republic; Tunisia; Turkey; Ukraine; United Kingdom; United States; Western Sahara China; Djibouti; Egypt; Eritrea; Hong Kong; India; Indonesia; Iran, Islamic Republic of; Japan; Korea, Democratic People's Republic of; Korea, Republic of; Kuwait; Madagascar; Malaysia; Mauritania; Oman; Pakistan; Saudi Arabia; Senegal; South Africa; Sri Lanka; Sudan; Suriname; Taiwan, Province of China; Thailand; United Arab Emirates; Vietnam
Because common dolphins occupy a wide range of habitats, from nearshore areas to open ocean, their prey also varies. While some populations feed in productive offshore zones and concentrate on fish and squid species associated with the deep scattering layer,5 others eat a variety of schooling fishes like anchovies, sardines, and mackerel, more common to continental shelf or coastal areas4,6-8. Common dolphins are known to form large mixed- species groups with spinner, striped, and spotted dolphins in areas where their ranges overlap9. This is the case in the Indian Ocean, particularly off the coast of South Africa where common dolphins are observed feeding with other cetacean species during the annual ‘sardine run’. Common dolphins are also known to associate with tuna when both species are feeding on schooling fish.
Common dolphins can form groups of hundreds, or even thousands of individuals. Gestation is estimated to last 10-12 months, and females produce calves once every two to three years. Calves are weaned at between 5 and 6 months in the Black Sea, but possibly later in other areas. The maximum estimated age for the species is 30 years4.
As with other dolphin species, killer whales and large sharks are the most likely natural predators of common dolphins, although they may also be preyed on by false killer whales, or pilot whales in some areas.
In the Eastern Tropical Pacific, the Atlantic and the Indian Oceans, common dolphins’ association with yellowfin tuna brings the species into contact with tuna fisheries and puts them at risk of by-catch, 4,10 particularly in gillnet or purse seine fisheries11-14. While bycatch is pervasive throughout the species’ range, habitat degradation, contamination, disease, and overfishing are thought to play a bigger role in the documented population declines in the Black Sea and Mediterranean subpopulations15-18.
There have been directed hunts for common dolphins in Japan and off the coast of Peru where they are used for bait shark fisheries as well as for human consumption19. Globally, common dolphins are designated as Least Concern on the IUCN Red List of Threatened Species20, but the Mediterranean subpopulation is listed as Endangered15, and the Black Sea subspecies is listed as Vulnerable17. These latter two are listed on Appendix II of the Convention on Migratory Species (CMS).
Please see the IWC Whalewatching Handbook