The diet of an adult harbour porpoise is made up of various pelagic and demersal fish, as well as invertebrates. In the Southern North Sea, it consists mainly of small benthic fish, herring, cephalopod, whiting and cod. A daily meal would normally consist of about 5 kilos fish (around 10% of the body

• is a stocky, rotund animal with a broad-based, low, triangular dorsal fin and small, oval pectoral flippers.
• has a short-beaked head with a dark line that runs from the back of the mouth to the leading edge of the dorsal fin.
• has a comparatively thick layer of blubber which varies in thickness over the body. Blubber thickness can also be affected by nutritional status.
• are very dark grey to black on their back, becoming speckled/intermediate on their sides and white on their underside.
• has straight mouth-line slopes upwards towards the eye (Jefferson et al, 2008).
• tail flukes are defined by a deep median notch, have concave trailing edges and rounded tips (Watson, 1981).
• has 19-28 teeth in each tooth row (Jefferson et al, 2008). Each tooth has a cylindrical ‘neck’, flattened into a spatulate form at the tip.
• tongue has finger-like extensions around its edge known as marginal lingual papillae. These are age-related structures helping to seal the mouth during suckling and then aiding the eating of solid food whilst excluding seawater following weaning (Natural History Museum, 2002).

• Phocoena. p. phocoena in the North Atlantic
• Phocoena. p. vomerina, in the eastern North Pacific
• Phocoena. p. relicta in the Black Sea (Reeves and Notarbartolo di Sciara 2006)
• An un-named subspecies in the western North Pacific (Rice, 1998)

The harbour porpoise is listed on Appendix II of CITES and Appendix II of the Bern Convention and Annexes II and IV of the EC Habitats Directive. It is also on Appendix 2 of the Bonn Convention (Anon, 1999z). All species of cetaceans are given protection under the Wildlife and Countryside Act 1981 and the Wildlife (Northern Ireland) Order 1985 (Anon, 1999z). All cetacean species are listed on Annex IV (Animal and Plant Species of Community Interest in Need of Strict Protection) of the EC Habitats Directive (Anon, 1999x). All whales are listed on Annex A of EU Council Regulation 338/97 and therefore treated by the EU as if they are on CITES Appendix I thus prohibiting their commercial trade (Anon, 1999x). Whaling is illegal in UK waters (Fisheries Act 1981), but neighbouring countries maintain the right to hunt (Anon, 1999x). An 'Agreement on the Conservation of Small Cetaceans in the Baltic and North Seas' (ASCOBANS), formulated in 1992, has now been signed by seven European countries, including the UK. Under the Agreement, provision is made for protection of specific areas, monitoring, research, information exchange, pollution control and heightening public awareness. Although aimed primarily at dolphins and porpoises, ASCOBANS includes all toothed whales except the sperm whale (Anon, 1999x).

In the Baltic Sea area the historic range apparently included all of the Kattegat/Skagerrak area, the Gulfs of Riga, Finland, and Bothnia, and much of the Baltic Sea proper. However, in the latter half of the 1900s, the range was reduced considerably, and currently porpoises are considered to be virtually absent in the north-eastern Baltic (Koschinski 2002).

Found in coastal regions of the North Atlantic, Arctic, and North Pacific Oceans; also the Mediterranean and Black Sea regions. They are found in bays, estuaries, river mouths, and sometimes ascend further up rivers.

Biogeographic Regions: nearctic (Native ); palearctic (Native ); arctic ocean (Native ); atlantic ocean (Native ); pacific ocean (Native ); mediterranean sea (Native )

Other Geographic Terms: holarctic

occurs (regularly, as a native taxon) in multiple nations

Canada

Origin: Native

Regularity: Regularly occurring

Currently: Present

Confidence: Confident

Type of Residency: Year-round

United States

Origin: Native

Regularity: Regularly occurring

Currently: Present

Confidence: Confident

Type of Residency: Year-round

Global Range: (>2,500,000 square km (greater than 1,000,000 square miles)) Temperate and ice-free boreal zone of northern hemisphere; summer visitor to the productive fringes of the Arctic Ocean (Gaskin 1992; Suydam and George, 1992, Can. Field-Nat. 106:489-492); isolated population in the Black Sea; south to Senegal in the eastern Atlantic. Has disappeared from parts of the Baltic Sea, the southern North Sea, and portions of the central California coast (see Read et al. 1993). See also IUCN (1991) for distribution information.

Phocoena phocoena, also known as the "Common" or "Harbor" Porpoise, is a small cetacean that is 1.5 to 2 meters long and weighs from 45 - 65 kilograms. The female of the species is usually slightly larger than the male. The color of the animal varies from individual to individual, but the most common coloration pattern is a dark dorsal surface that shifts to a lighter colored hue ventrally. Although the dark color is usually black or deep gray, albinos have been reported in which the dark segments are completely or partially white. The flippers, dorsal fin, and tail are all dark in color, and there is a black stripe that runs from the edge of the mouth or eye to the flipper on either side. There is no noticeable forehead or beak on this species, and the snout is short, giving the head a somewhat cone-like shape. P. phocoena has two pectoral flippers, a single dorsal fin, and a tail with two partially separated flukes. All of these appendages are short and not very sharp, with the dorsal fin being triangular shaped and usually around 15 - 20 cm tall. There is a noticeable keel located near the all dark tail flukes, with the tail itself spanning anywhere from 30-65 cm. Inside the slightly upturned mouth there are rows of 16-28 spade-shaped teeth. There is no variance in the shape or type of teeth in P. phocoena.

Range mass: 45 to 60 kg.

Range length: 1.5 to 2 m.

Sexual Dimorphism: female larger

Average basal metabolic rate: 107.675 W.

Length: 1800 cm

Weight: 54000 grams

• Marine

• Marine

Found in both salt and fresh water areas, Phocoena phocoena require a shallow coastal body of water. In the Western Atlantic, they also move far out to sea near the end of summer and reappear in spring. Other regional populations move south or farther away from shore to avoid ice buildups.

Habitat Regions: temperate ; polar ; saltwater or marine ; freshwater

Aquatic Biomes: pelagic ; rivers and streams; coastal ; brackish water

Other Habitat Features: estuarine

Habitat Type: Marine

Comments: Coastal waters and adjacent offshore shallows; also inhabits inshore areas such as bays, channels, and rivers. Mothers and young tend to move into sheltered coves and similar sites soon after parturition.

Non-Migrant: Yes. At least some populations of this species do not make significant seasonal migrations. Juvenile dispersal is not considered a migration.

Locally Migrant: Yes. At least some populations of this species make local extended movements (generally less than 200 km) at particular times of the year (e.g., to breeding or wintering grounds, to hibernation sites).

Locally Migrant: No. No populations of this species make annual migrations of over 200 km.

May make seasonal inshore (summer) - offshore (winter) or north (summer) - south (winter) migrations, though movements often are related to movements of prey species (IUCN 1991).

Diet consists mainly of smooth, non-spiny fish, and cephalopods. Herring, pollack, hake, sardines, and cod are commonly eaten. Other sea creatures such as squid and shrimp are also consumed. P. phocoena produces click-like sounds similar to those used by other cetaceans as a means of echolocation in order to locate food.(Johnston(1999), Nowak(1999))

Animal Foods: fish; mollusks; aquatic crustaceans

Primary Diet: carnivore (Piscivore )

Comments: Eats various fishes, squid, and crustaceans. In summer in the Bay of Fundy, adults fed mainly on clupeid and gadid fishes while euphausiids were the most common prey of calves (Can. J. Zool. 70:1629).

10,000 to >1,000,000 individuals

Comments: Total population for the Gulf of Maine/Bay of Fundy was estimated at 37,500 in 1991, 67,500 in 1992, and 74,000 in 1995 (NMFS 1999). In the 1980s, population from California to Washington was estimated at about 50,000 (Barlow 1987, cited by IUCN 1991). See IUCN (1991) for population estimates for other parts of the range.

Social; travels in groups of 2-10, sometimes up to 50 individuals; may segregate by sex and/or age.

Comments: Active day/night.

Average lifespan

Status: wild: 13.0 years.

It is not clearly known how extensive the mating season is in P. phocoena, but it seems that mating mainly occurs from June to September with births occurring from May to August. It is commonly noted that gestation lasts 11 months with nursing following for another 7 or 8 months. A female will give birth to one calf per year, with the birth size of the calf being 6-8kg and 70-100cm long. Sexual maturity is reached by the fifth year, if not before, and the life span of P. phocoena is believed to be anywhere from 6 to 20 years. (Johnston(1999), Nowak(1999))

Breeding interval: A female will give birth to one calf per year

Breeding season: Mating mainly occurs from June to September

Average number of offspring: 1.

Average gestation period: 11 months.

Range weaning age: 7 to 8 months.

Range age at sexual or reproductive maturity (female): 5 (high) years.

Range age at sexual or reproductive maturity (male): 5 (high) years.

Key Reproductive Features: iteroparous ; seasonal breeding ; gonochoric/gonochoristic/dioecious (sexes separate); viviparous

Average birth mass: 7000 g.

Average gestation period: 320 days.

Average number of offspring: 1.

Breeds in summer. Following a gestation of 10-11 months, a single calf is born between May and early August. Females breed each year. Young weaned in 8 months. In Bay of Fundy, sexually mature in 3-4 years (5-6 years in north Sea). Few live beyond 7-8 years.

Blubber between the porpoise's dorsal fin and tail flukes decreases amount of metabolic energy needed to swim because it is crosshatched with elastic fibers.

Although fishing of P. phocoena is now illegal in most areas, the species is still in danger. Deliberate and accidental deaths still occur because modern fishing nets are almost undetectable to porpoises. Since these nets are commonly used in nearshore areas, in the natural range of P. phocoena, they probably kill large numbers of porpoises. Various measures are being taken in the United States and other nations in an attempt to limit deaths of this kind. In addition to deaths related to fishing, porpoises also suffer from chemical and noise pollution. (Dollinger(1988), Johnston(1999), McWilliam(1999), Nowak(1999))

CITES: appendix ii

IUCN Red List of Threatened Species: critically endangered

Canada

Rounded National Status Rank: N3 - Vulnerable

United States

Rounded National Status Rank: N4 - Apparently Secure

Rounded Global Status Rank: G4 - Apparently Secure

Comments: Mortality due to entanglement and entrapment in commercial fishing gear may contribute to depletion of local populations in western Greenland, Gulf of St. Lawrence, Newfoundland, Bay of Fundy, and Gulf of Maine (Read and Gaskin 1988, Read et al. 1993, Caswell et al. 1998, NMFS 1999), as well as in other parts of the world (IUCN 1991). The average annual mortality estimate for 1992-1997 for U.S. Atlantic fisheries was 1,749 individuals (NMFS 1999). Bycatch in the Bay of Fundy in Canada was estimated at approximately 100-425 porpoises per year in the early 1990s (Trippel et al. 1996). Bycatch reduction efforts are in operation, and NMFS (1999) regarded these as sufficient to reduce the bycatch to sustainable levels. Habitat modification and environmental contaminants do not appear to be a significant threat in the Gulf of Maine/Bay of Fundy (NMFS 1999).

Management Requirements: Harbor porpoises in the Gulf of Maine and Bay of Fundy appear to comprise a relatively discrete population unit that can be managed as a separate stock (NMFS 1999).

Needs: Protection from excessive mortality in commercial fisheries is an important consideration (IUCN 1991, NMFS 1999); regulate and monitor fisheries to maintain bycatch at sustainable levels. January 1994). A variety of local stocks should be protected, since there seems to be relatively little gene flow among populations (Gao and Gaskin 1996).

Taken heavily in various areas, the meat is used for human and animal consumption, and its oil is used in lamps and as a lubricant.

Comments: See IUCN (1991) for information on historical and present harvest; Greenland is the only country presently reporting large direct catches; use is mainly for human consumption; there is no longer a major commerical harvest, though resumption of commercial harvest may occur in Turkey (IUCN 1991).

Comments: Various data indicate that four distinct populations exist in the western North Atlantic Ocean: Gulf of Maine/Bay of Fundy; Gulf of St. Lawrence; Newfoundland; and Greenland (NMFS 1999). Patterns of morphological variation in metric skull characters suggest that gene flow among populations is restricted to some degree even among closely adjacent geographical units (Gao and Gaskin 1996).