Harbour Porpoise (Phocoena phocoena) The Harbour Porpoise (Phocoena phocoena) is one of six species of porpoise, and so one of about eighty cetacean species. The Harbour Porpoise, as its name implies, stays close to coastal areas or river estuaries and as such is the most familar porpoise to whale-watching enthusiasts. This porpoise often ventures up rivers and has been seen hundreds of miles from the sea The species is sometimes known as the Common Porpoise in texts originating in the United Kingdom, though this usage appears to be dying out in favour of the American terminology. Population and distribution: The species is widespread in cooler coastal waters in the Northern Hemisphere, largely in areas with a mean temperature of about 15 °C. In the Atlantic, Harbour Porpoises may be present in a concave band of water running from the coast of western Africa round to the eastern seaboard of the United States, including the coasts of Spain, France, the United Kingdom, Ireland, Norway, Iceland, Greenland and Newfoundland. There is a similarly-shaped band in the Pacific Ocean running from Sea of Japan, Vladivostok, the Bering Strait, Alaska and down to Seattle and Vancouver. There are diminishing populations in the Black and Baltic Seas. Conservation: Harbour Porpoises are not and never have been actively hunted by whalers because they are too small to be of interest - an adult is about the same size and a little lighter than the average adult human. The global population is in the hundreds of thousands and the Harbour Porpoise is not under threat of widespread extinction. However a key concern is the large number of porpoises caught each year in gillnets and other fishery equipment. This problem has lead to a documented decrease in the number of Harbour Porpoise in busy fishing seas such as the Black and Baltic. It is known that the porpoises' echo location is sufficiently discriminating to detect the presence of the nets, however this does not stop porpoises from becoming trapped. Scientists have developed beacons to attach to the nets to try to deter curious porpoises. This are not yet in wide use and have not been widespread approval - some concerns have been raised about the value of adding more noise pollution to the seas.