How Many Dolphin Species Are There?

The 10,000 Islands Dolphin Study Project is the only team that monitors the daily activity of the bottlenose dolphin population of the Marco Island area. Data is collected on board the Dolphin Explorer to document the travel range, feeding habits, social behavior, genealogy, survival rate and overall health of the local population and has a longevity of 18 years of information. The study continues…

For those who have followed our articles over the years, you know that discussions focus primarily on the bottlenose dolphin population found in our area waters of Marco Island. Stories of rescue, survival, habits and habitat have dominated the columns in the Coastal Breeze News.

Today, we are spreading our wings to learn more about the worldwide population of dolphins and how they differ. So, how many different species of dolphins are there in the world? Depending upon the source, there are 40 to 42 species still roaming the global waters.

Of these species, five are classified as “river” dolphins, while the rest are “oceanic” species. The river dolphins are freshwater inhabitants by nature living in the Amazon, Ganges, Indus, Yangtze and rivers of Argentina and Brazil. Most of these river dolphins are endangered, critically endangered, or vulnerable. Most are on this list because of habitat loss, primarily due to human expansion into their natural living areas.

Of the oceanic species, the White Beaked Dolphin is found northernmost, dwelling in the cold North Atlantic waters that include Iceland, Greenland and parts of Europe. In the southern hemisphere, the Southern Right Whale dolphin calls those cold waters home. Also, in Antarctica, you can find the Hourglass Dolphins. The majority of the other species patrol tropical, sub-tropical and temperate climates to call home.

Now, the largest dolphin species is actually misnamed. Known as the “Killer Whale,” the Orca is an apex predator with no other predators of its own. These are, indeed, the largest of the dolphins and, fully grown, can get as big as 31 feet long and weigh up to six tons! They are not the only “whales” that are actually dolphins. You can include Pilot Whales and Melon-headed Whales in that category as well.

The smallest dolphins on the planet are called Hector’s dolphins, found in the New Zealand waters and discovered by Sir James Hector. Mature adults will only grow to four to five feet long with a high weight of about 130 pounds. Maui dolphins are a subspecies of the Hector dolphins, found off the west coast of New Zealand’s North Island. They are one of the rarest and smallest subspecies on the planet, with a population less than 50 dolphins.

Very interesting information! However, the most populous species and most familiar is the Bottlenose dolphin. They are found throughout the world along coastlines and in the offshore deeper waters. They are widely studied because of their coastal habitation and ease to observe.

The scientific name for the Common Bottlenose dolphin is Tursiops truncatus. In 1865, a species of Common Bottlenose dolphins called Tursiops erebennus was named but became blended with the Truncatus species. Recent morphological studies have concluded that coastal bottlenose in the Atlantic is different from the larger offshore bottlenose, so don’t be surprised if a new species makes the list in the near future.

So, lots of dolphins are out there worldwide, and each species is different in looks and habitats. No matter where you go, keep a good lookout for the fin rising from the water. You could be seeing something special!