Striped Dolphin

Latin: Stenella coeruleoalba

Physical Description

The striped dolphin is a streamlined oceanic dolphin, similar in shape and size to the common dolphin and measuring up to 2.6 metres in length. It has a long beak, a large curved dorsal fin and short tapered pectoral fins. Striped dolphins have a distinct colour pattern: the beak, melon, back, dorsal and pectoral fins are dark grey whilst the throat and belly are very pale; there are usually three dark grey stripes running from the eye to the anus, one to the pectoral fin and a third short stripe between the other two; the eyes are normally outlined by a dark patch; starting above the eye, a blaze of pale grey sweeps along each flank.

Habitat and Distribution

The striped dolphin is wide ranging throughout tropical and temperate waters. Sightings in UK coastal waters normally occur during the warmer summer months. Overall sightings of striped dolphins off the west coast of Scotland are rare and records also include stranded animals.

Behaviour

Striped dolphins can be very acrobatic, making them fairly conspicuous at the sea surface. Group size varies but they are renowned for travelling in large groups of several hundred animals, although this has not been recorded in the Hebrides. Capable of reaching speeds of up to 23 mph, striped dolphins frequently bow ride boats.

Food and Foraging

The diet of the striped dolphin is varied and may include fish, squid, octopus, krill and crustaceans. They feed anywhere within the water column where prey is concentrated and they can dive to depths of 700 metres to hunt deeper-dwelling species.

Status and Conservation

Globally, striped dolphins are considered common within their range; they are uncommon in UK waters. The most notable threats to striped dolphins include entanglement in fishing nets, reduction in prey availability due to overfishing and contamination from pollutants. In Japan the striped dolphin is the subject of intensive drive hunts: large groups of dolphins are driven towards the shore and killed for meat. Striped dolphins are protected under UK and EU law, principally under Schedule 5 of the Wildlife and Countryside Act 1981, the Nature Conservation (Scotland) Act 2004 and by the 1992 EU Habitats and Species Directive.