The short-beaked common dolphin (Delphinus delphis) in Ionian Sea, Greece. This dolphin has been in decline in the Mediterranean Sea since the 1960s. Between 1996 and 2007 numbers declined in the Ionian sea from 150 to 15 individuals. Overfishing in the area is thought to have reduced the amount of available prey.

Photograph: Chris & Monique Fallows /NPL/WWF