Once one of the most abundant cetacean species in the Mediterranean Sea, common dolphins have declined throughout the region since the 1960s. The causes of their generalised decline include prey depletion by overfishing and incidental mortality in fishing gear. At present, two species are recognized unanimously; the short-beaked common dolphin D. delphis and the long-beaked common dolphin D. capensis. Only short-beaked common dolphins inhabit the Mediterranean Sea, and therefore in a Mediterranean context most of the time their name is shortened and they are referred to as ‘common dolphins’.
The common dolphin has a distinctive creamy yellow hourglass pattern along the sides, with a dark grey back, tail and flippers and a cream coloured belly. The beak is relatively long and slender. Adult short-beaked common dolphins measure between 1.8 to 2.3 metres long and weigh about 100 kg. Lifespan is about 20 to 30 years.