Atlantic white-sided dolphin pictures and facts

The Atlantic white-sided dolphin (Lagenorhynchus acutus) is one of two white-sided dolphin species, the Pacific white-sided and the Atlantic white-sided. While its English name emphasizes its white coloration, the dolphin stands out because of an unusual pale yellow patch behind its dorsal fin. The remainder of its coloring – a blend of white, gray, and black – is shared with other dolphin species. The Atlantic white-sided dolphin’s chin, throat, and abdomen are white; its pointy dorsal fin, back, and flippers are mostly gray to black; and a light gray stripe runs from its beak to its tail.

The Atlantic dolphin is noticeably more robust than its Pacific cousin. In fact, it’s among the largest of the 32 known dolphin species. The Atlantic dolphin is approximately a meter long at birth. Females grow to be 2.5 meters (8.2 feet) long, and males grow to be 2.8 meters (9.2 feet) long. Adult weights range from 200 to 230 kilograms (440-506 pounds). The dolphins have a lifespan of about 25 years and reach sexual maturity between ages 6 and 12. Females tend to give birth to a single calf every other year.

The dolphin is a social animal, traveling in groups of up to 500 members. Its friendliness is often extended to human visitors; Atlantic white-sided dolphins are known to approach boats in order to interact with humans and to play in boat wakes. Humans enjoy the animals' acrobatics, and many tours are scheduled for the sole purpose of watching the dolphins breach during migration. The dolphins occasionally venture into coastal waters, but they generally migrate along the continental shelf in waters that are 40-270 meters (181-885 feet) deep.

Historically, human influences seriously harmed the dolphin population. Fisherman from Norway, Newfoundland, and the Faroe Islands hunted the mammal for its meat and blubber. Thanks to the Marine Mammal Protection Act of 1972, today the species is protected throughout its natural habitat, the North Atlantic Ocean. Between 60,000 and 300,000 Atlantic white-sided dolphins inhabit the North Sea and waters along the northeastern coast of the United States, the coast of Newfoundland, and the water between the United Kingdom, Iceland and Greenland.

However, accidental entrapment in fishnets and deliberate hunting for dolphin meat remain threats. Furthermore, several mass strandings of dolphins have been reported in the northeastern United States. The strandings have puzzled humans, but they seem to be related to dolphins’ interactions with fisheries. Dolphins and other marine life are also threatened by increasing concentrations of toxins in the ocean. Their natural predators include sharks and killer whales.

Analyses of Atlantic white-sided dolphins’ stomach contents indicate that the mammal feeds on squid, shrimp, and fish such as herring and smelt.

Drawing of the Atlantic white-sided dolhpin licensed under GNU Free Documentation License