Cetaceans - Whales, Dolphins and Porpoises
Cetaceans evolved from land mammals having a common ancestor with pigs and hippopotamuses that adapted to marine life about 50 million years ago. They are the mammals most fully adapted to aquatic life. Their body is streamlined with the fore-limbs modified into flippers and the hind-limbs tiny and rudimentary and not attached to the backbone but hidden within the body. The tail has horizontal flukes. Cetaceans are nearly hairless, and are insulated by a thick layer of fatty blubber. Cetaceans are known to be highly intelligent.
There are ninety species of whales, dolphins and porpoises worldwide, of which 29 have been recorded in British waters. They vary widely in size and appearance : for help with identification, please visit this page .
Conservation status
All cetaceans are protected by law in the UK : the Whaling Industry (Regulations) Act 1934, amended by the Fishing Limits Act of 1981, prohibits the use of any ship for the whaling of any species of cetacean within United Kingdom Fishery Limits, and twenty-one species of cetaceans are named in the United Kingdom Biodiversity Action Plan (click on Access Species etc.) and are accorded special protection.
Despite a worldwide ban on commercial whaling in 1986, whales are even more threatened than before. Norway resumed whale hunting in 1993, and Iceland followed in 2003 whilst Japan never stopped hunting, citing "scientific research." More than 30,000 whales have been killed for commercial purposes since the ban on whaling began over 20 years ago. The Government of Japan announced plans to add 50 humpback whales to its annual whaling target list of Minke whales although its Antarctic whale hunt for 2007 was abandoned early after a fire on one of the whaling ships which caused the death of a crew member.
Besides hunting, whales also face a number of other man-made threats. These include ship strikes, accidental entanglement in fishing nets, pollution, habitat destruction and disturbance from noise of shipping, oil and gas production, underwater construction and military sonar (see this page.)