Close relatives to whales and porpoises, dolphins have provided inspiration for art and fables since people first spotted them. Curious, intelligent, and friendly, these sleek marine mammals live in waters from Antarctica to the Arctic. A few species can be found in fresh water environments, but most need clean ocean water to survive. Worldwide, there are almost forty known dolphin species. Let’s take a closer look at some of the most often encountered.
The Common Dolphin
Not a very exciting name; yet, encountering one of these dolphins is always a thrill. There are two species of common dolphin: the Short-Beaked Common Dolphin, and the Long-Beaked Common Dolphin. Not to be confused with the common Dolphinfish, or Mahi-Mahi, both species can be found in tropical to warm-temperate environments throughout the world. Short-Beaked Dolphins prefer deeper waters along shelves, particularly in areas where bottom topography offers dramatic peaks and valleys. Long-Beaked Dolphins prefer warm, shallow coastal areas and can sometimes be seen from shore. Both species are fond of riding boats’ bows, and have even been seen riding baleen whale wakes. Sometimes aggregating by the thousands, these dolphins are often found in the company of other cetaceans.
Bottlenose Dolphin
Although Bottlenose Dolphins are sometimes referred to as “common dolphins”, they are a separate, though closely related group of species. Captive Bottlenose and Common Dolphins have bred with one another, producing fertile hybrid offspring. It is not known whether this behavior occurs in wild populations, however another hybridization, the Wolphin, which is a hybrid between a false killer whale and a bottlenose, has been seen in the past. While pods of bottlenose dolphins are usually comprised of 10-30 individuals, they are sometimes encountered in groups of up to 1,000 members. With unmistakable grey coloring, these animals are found in warm and temperate seas worldwide.
False Killer Whale
The third largest of all dolphin species, this dark grey dolphin looks nearly black and has a pronounced but much shorter fin than its distant cousin, the Orca. Like Orcas, False Killer Whales attack and kill other dolphins; but no attacks on divers have ever been recorded. Usually encountered in shallow waters from Scotland to Argentina, and in the Mediterranean and Red Seas, the Lakshadweep Islands and coastal areas in the Indian Ocean, and in the Pacific Ocean from New Zealand to the Sea of Japan and to Hawaii, the species is quite rare and scientists estimate that only ten major populations remain.
Atlantic Spotted Dolphin
Distributed only in the Atlantic Ocean, and living in pods, these dolphins are medium sized, reaching an average length of about two meters. Born grey, the dolphins’ spots become more pronounced with age. Like bottlenose dolphins, common dolphins, and several other species, they have white bellies which make them hard for predators to see from below. And, like their close cousins, they are very friendly and sometimes seek human contact; the Bahamian population has become extremely habituated to humans. You’ll find these dolphins around the Canary Islands and Azores, in Florida and the Gulf of Mexico, and as far north as Cape Cod. They have been encountered in Brazil’s Rio Grande do Sul area, and even in West Africa.
Spinner Dolphin
While all spinner dolphins inhabit warm tropical and subtropical waters throughout the world, and while all have several features in common, there are actually four distinct subspecies. In general though, spinner dolphins are small, ranging in size from 1.25 to just over 2 meters. Pods tend to move from one place to another, with some families preferring to inhabit deep offshore waters, and others preferring shallow areas. Often hunting in packs, circling schools of fish, and herding them into tight balls or “donuts” for easy feeding, these animals are extremely athletic and gregarious. They’re often seen in Hawaiian waters, with friendly populations around the Big Island’s Kona Coast and offshore from Oahu. Named for their tendency to spin rapidly while leaping in fantastic acrobatic displays, they are always fun to watch.
White Sided Dolphin
There are two distinct white sided dolphin species: the Atlantic White Sided Dolphin, and the Pacific White Sided Dolphin. Both species are dark grey to black with distinct white shading along their sides. Atlantic White Sided Dolphins can be found in cool to temperate North Atlantic Ocean locations as well as in the North Sea and Baltic Sea. At a length averaging 2.5-2.8 meters, they’re larger than many other species. This species is still subject to hunting in some areas; even so, the animals are plentiful and are of “Least Concern” status, according to the IUCN. Pacific White Sided Dolphins are also plentiful, and like their Atlantic cousins, prefer colder waters than most other species do. Distributed from the Bering Sea all the way to the Baja Peninsula, and throughout the Sea of Japan and the Sea of Okhotsk, these are very friendly dolphins which have a tendency to approach boats and divers. British Columbia, the Washington and Oregon coasts, and Alaska are all very good places to encounter them.
Commerson’s Dolphin
With a distinct black and white pattern, this stocky little 1.5 meter dolphin is extremely active and social. Living mostly off the southern coast of South America around the Falkland Islands, Argentina, and the Strait of Magellan, and found in the Kerguelen Islands in the southern Indian Ocean as well, they put on incredible acrobatic displays both above and beneath the water’s surface. They will interact with divers and also greet boats eagerly, riding bow waves and even spinning as they leap through the air.
Dusky Dolphins
Only found in the Southern Hemisphere, with most being around New Zealand and off the coast of South America and Africa, the Dusky Dolphin can be found around many oceanic islands and off Tasmania and southern Australia as well. Often living in large groups numbering 50-100 individuals, they have a tendency to separate into nursery groups, in which mothers and calves stay in shallow water, and in breeding groups, which also come together near shore but which sometimes can be encountered in shallow water. Social and playful, with a tendency to perform flips and high, graceful leaps, these dolphins are protected throughout their range and seem to enjoy interacting with humans.
Almost all dolphins communicate with one another via a series of clicks, whistles, and squeaks, which you might hear while you are diving. They have a tendency to watch divers from a distance before coming up for a closer look, sometimes zooming straight up to people in the water and stopping just inches away. Remember, if you’re diving with dolphins, you are visiting them in their homes. Never harass them, and allow them to set the tone for the encounter. By giving them their space and respecting their territory, you’ll allow them to feel more comfortable; and in turn, they will be more likely to interact with you.