Whales and dolphins exhibit some of the most fascinating adaptations to aquatic life of any animal. Hunted to near extinction in the 1800s many species of whale are at dangerously low levels despite a moratorium on commercial whaling. Fishing, pollution, habitat destruction and disturbance pose growing threats to all cetaceans.

fact file: bottlenose dolphin
Tursiops truncatus
A lively grey dolphin found around the world, some of the largest specimens are found around the UK.
Behaviour: Lively, acrobatic, intelligent.
Food: fish, crustaceans and squid.
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fact file: harbour porpoise
Phocoena phocoena
The smallest cetacean regularly seen around the UK, often close inshore.
Age: To 12 years – short-lived relative to other cetaceans
Threats:  entanglement in fishing nets, pollution.
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factfile: northern bottlenose whale
Hyperoodon ampullatus
The memorable visitor to the Thames in Spring 2006, usually a deep-sea diver in distant Atlantic waters
Weight: to 7,500 kg
Threats: occasional whaling, underwater noise

• Whales, dolphins and porpoises are warm-blooded marine mammals which belong to the Order Cetacea.
• Cetaceans are totally independent of land - they are mammals that have become aquatic and adapted to life in the ocean.
• Cetaceans range in size from the smallest dolphins and porpoises at a metre or so in length. to the enormous blue whale - the largest animal on earth - which can grow to more than 30m in length.
• Cetaceans have streamlined, hydrodynamic bodies.
• All cetaceans must breathe air. Their blow hole allows them to expel air quickly at the surface.
• Cetaceans are warm-blooded mammals and must maintain a stable body temperature (36°-37°C), for which they have an insulating layer of fat or blubber of up to 50cm thick.
• Baleen whales. including the blue. fin. humpback right. sei. Bryde’s. bowhead. minke and grey whales feed on plankton. Toothed whales include the sperm. beaked. beluga. narwhal. killer and pilot whales. and the dolphins and porpoises. They feed on larger fish. squid and other marine animals.

threats
All cetaceans are affected by man’s activities. Some have been hunted to the verge of extinction - commercial whaling has been responsible for the near demise of many species, including the blue and humpback whales. Others, particularly the river dolphins, suffer from the degradation of their habitat. Still others become entangled and drown in fishing gears, whilst all are affected by pollution.

Factsheets & books about whales and dolphins can be ordered from the MCS shop