Atlantic White-sided Dolphin

Lagenorhynchus acutus

The Dolphin most likely to be spotted on inshore trips in the Gulf of Maine is the Atlantic White-sided Dolphin. The Harbor Porpoise may actually be more common, but it is certainly harder to see due to its avoidance of boats and small size.

 Photographed on Jeffreys Ledge in July 2001 by Steve Mirick and used with his permission.

Some people are surprised to learn that Dolphins are whales and Killer Whales are closely related to Dolphins.

Dolphins and porpoises along with Pilot, Sperm and Killer Whales are toothed whales as opposed to the larger baleen whales.  The toothed whales and dolphins  have 1 blow hole. Baleen Whales have 2.  This is clearly seen in this picture of the Atlantic White-sided Dolphin by Leonard Medlock.

The White-sided Dolphin has a short beak and the tall falcate dorsal fin is located in the center of the back.

The back is black and the belly white as in most marine animals. Most distinctive are the three color stripes on the sides. The Atlantic White-sided Dolphin has a gray ribbon like strip that extends from above the eye to the tail (A) . In the middle of the body the gray ribbon appears to be covered by the white patch (B). There is a gold or yellow strip above the gray ribbon to the tail (C). The colors do not show up well in this photograph by Steve Mirick.  The white patch shows up clearly even at a distance.

Notice the gray ribbon from the eye to the tail and the dark beak.
 

Two photos of Atlantic White-sided Dolphin by Len Medlock. The dolphin above is a baby. 

Adult White-sided  Dolphin slapping  tail on the water. Photo taken on the 9/8/09 NH pelagic.  The yellow strip and the white patch show clearly in this photo by Len Medlock.

If you take enough whale watches to Stellwagen Bank of Jeffreys Ledge you will eventually experience a pod of Atlantic White-sided Dolphin.

Even when the dolphins are not leaping from the water, you can see the white oval on the side followed by the golden stripe.