Dolphins are members of the cetacean family, which also includes whales and porpoises. There are more than 30 species of dolphin but not all live in the oceans - river dolphins are found in many countries such as Brazil, India, China and Pakistan.


Lifestyle
Most dolphins are social animals - some live in groups (called pods) of several hundred. They hunt in a variety of ways, sometimes in teams, feeding on squid, shrimp, eels and a wide variety of fish.

After a gestation period (pregnancy) of a year, a dolphin normally gives birth to a single calf that is almost half the length of its mother. It is able to swim immediately and is fully weaned at 18 months. Many calves stay with their mother until the age of three. Mature dolphins generally give birth every two to four years.


Activities
Dolphins are very playful and acrobatic mammals. Some can swim at speeds of up to 14 knots. They sometimes "spy hop", revealing the whole head and body down to the flipper for three seconds or more. Dolphins are often seen hitching a ride, "bow riding" in the bow wave in front of a ship. Dolphins can dive to depths of more than 300 metres and can jump up to six metres in the air.

Dolphins are extremely vocal - they make two kinds of sound:

Dolphins use a series of high-pitched clicks to build up a "sound picture" of their surroundings by listening to the echoes bouncing off objects. This enables them to tell the position of their prey and even its size and shape. This is known as echolocation.

Dolphins also produce high-pitched whistles and squeals, which they use to communicate with each other.

Dolphins around the UK
More than 20 species of cetacean have been recorded in UK waters. There are at least three populations of bottlenose dolphins known to live in mainland UK waters - in the Moray Firth, Scotland, Cardigan Bay, Wales, and off the coasts of Dorset, Devon and Cornwall. The population in Scotland is the most northerly known population. Harbour porpoises, smaller cousins to the dolphin, are also resident in UK waters.


Current threats & problems

Fishing
One of the greatest threats to dolphins is being caught in fishing nets. Hundreds of thousands are killed every year as they follow their staple food supply of fish, become entangled in nets and drown when they can't reach the surface to breathe. Each year, an estimated 10,000 cetaceans are killed in fishing gear around UK every year.

Commercial fishing also causes long-term problems for dolphin populations because their food supply is over-fished.

Pollution
Pollution is also a major threat to dolphins. Because they are at the top of the marine food chain, dolphins are particularly susceptible to pollution through food stocks that have been contaminated with a variety of chemicals, some of which can interfere with their ability to breed.


What WWF is doing

WWF has supported many dolphin projects around the world, including the conservation of some of the rarest species. In the UK, we are working with the Hebridean Whale and Dolphin Trust on a current research project, and we have funded studies of bottlenose dolphins off the Welsh coast. We also research the effects of pollution on marine mammals in general.

WWF's Oceans Recovery Campaign (ORCA) will also contribute to the well-being of the dolphin and other marine species. ORCA is identifying the many threats facing the UK's marine wildlife, and is campaigning for an increase in the number of Marine Protected Areas for wildlife including dolphins and porpoises, and the introduction of Fishing-Free Zones to help fish stocks recover from over-fishing and pollution.

In the longer term, WWF wants to see the introduction of an Oceans Act to provide the best possible protection of the marine environment - for wildlife and for people.

With your support, WWF will continue its work on oceans management and on the conservation of wetlands, both of which contribute to the safekeeping of these friendly, threatened mammals.