Atlantic white-sided dolphin

Lagenorhynchus acutus
Other names: 
  • Atlantic white-sided porpoise
  • Lag
  • Springer
  • Jumper
Maximum length: 
  • Male: 2.8m
  • Female: 2.5m
  • Calf: 1.2m
Maximum weight: 
  • Male: 235kg
  • Female: Unknown
  • Calf: Unknown
Diet: 
  • Small schooling fish (mackerel, hake, cod etc.)
  • Squid
  • Shrimp
Estimated population: 
175,000
IUCN Listing: 
LC
CITES Appendix: 
II
CMS Appendix: 
II (North and Baltic Sea populations)
Classification: 

The Atlantic white-sided dolphin was well known to early fishermen and whalers in the Atlantic Ocean. Its acrobatic nature earned it many names, including springer, jumper and springhval.

Appearance: 

The Atlantic white-sided dolphin is a stocky animal with a short stubby beak and a tall sickle-shaped dorsal fin. The black flippers have pointed tips and the tailstock is thick with a distinct keel. It has a black upper jaw and a black to dark grey cape with a broad grey lateral stripe. The Atlantic white-sided dolphin gets its name from the distinctive white stripe on its side, which starts just below the dorsal fin and runs into a yellow/ochre blaze continuing onto the tailstock which is easily seen when the animal is bow-riding or porpoising. It has a whitish lower jaw, throat, and belly to genital region, with a dark eye patch and face-flipper stripe. The Atlantic white-sided dolphin can be confused with both the white-beaked dolphin and the common dolphin, but differences in size and a good look at the bright yellow colouration pattern will avoid misidentification.

Behaviour: 

These cetaceans can be shy and less demonstrative than other dolphins, but are just as capable of performing impressive leaps and breaches. They are fast swimmers and will occasionally bow-ride and lobtail. They form pods of 30-150 individuals, but it is not uncommon to see some 500, or even occasionally low thousands, of animals associating over dense concentrations of food. Atlantic white-sided dolphins are known to associate with white-beaked dolphins, pilot whales and bottlenose dolphins as well as fin whales and humpback whales. In these congregations they may be feeding on similar prey items, or they may just be socialising. They are highly social animals and are known to individually and mass strand. The average life-span for an Atlantic white-sided dolphin is between 22 and 27 years.

Distribution: 

Atlantic white-sided dolphins are found in temperate and cold waters of the north Atlantic Ocean, usually over deep-slope continental shelves and canyon waters. The main threats facing this species are targeted hunts from drive fisheries in the Faroe Islands and Greenland, incidental entanglement in fishing gear (mid-water trawls are of most concern), climate change, and contamination from chemical pollution. The IUCN categorises this species as of Least Concern.

Distribution map: