The harbor porpoise(Phocoena phocoena) is a small toothed whale that lives in cold water, and can often be found in small pods of 2-5 porpoises.
The harbor porpoise is sometimes called the "puffing pig" - in fact, the name porpoise comes from porcus, which is the Latin word for pig. They are also known as the common porpoise.
Harbor porpoises are 4-6 feet long and weigh 110-130 pounds. Females are larger than males. These porpoises have a robust body and a blunt snout.
Harbor porpoises have a dark gray back, and white chin and belly. The white coloration on the belly turns into a mottled coloration on the porpoise's flanks. They have a gray stripe that runs from the back of the mouth to the flippers. Harbor porpoises have a small, triangular-shaped dorsal fin, that has tubercles (bumps) on its leading edge.
Harbor porpoises have thick blubber, which helps them conserve heat in cold water. They have 19-28 spade-shaped teeth on each side of their upper and lower jaw (click here to see a picture of harbor porpoise teeth).
- Kingdom: Animalia
- Phylum: Chordata
- Subphylum: Vertebrata
- Superclass: Gnathostomata, Tetrapoda
- Class: Mammalia
- Subclass: Theria
- Order: Cetartiodactyla
- Suborder: Cetancodonta
- Suborder: Odontoceti
- Infraorder: Cetacea
- Superfamily: Odontoceti
- Family: Phocoenidae
- Genus: Phocoena
- Species: phocoena
The Society for Marine Mammalogy lists 4 subspecies of harbor porpoise:
- Phocoena phocoena phocoena: Atlantic harbor porpoise
- Phocoena phocoena vomerina: Eastern Pacific harbor porpoise
- Phocoena phocoena relicta: Black Sea harbor porpoise
- Phocoena phocoena un-named subspecies: Western Pacific harbor porpoise
Habitat and Distribution:
Harbor porpoises may be found in the open ocean, but also in estuaries, bays, harbors and fjords. They inhabit temperate and sub-arctic waters in the North Pacific and North Atlantic Oceans, and the Black Sea.
Harbor porpoises eat fish (both schooling fish and bottom-dwelling fish) and squid.
Harbor porpoises find their prey using echolocation, which is similar to sonar and involves the emission of high-frequency sound waves that bounce off objects around the porpoise and are received back into its lower jaw. They are then transmitted to the inner ear and interpreted to determine the size, shape, location and distance of prey.
Harbor porpoises are sexually mature at 3-4 years of age, and are physically mature when they are 5 (males) to 7 (females) years. Mating occurs in the late summer, and the female gives birth to a calf that is about 2 feet long at birth after a 10.5 month gestation period. The calves can eat small prey when they are a few months old, and are weaned before they turn one year old. In some areas, females have calves every year.
Harbor porpoise males are said to be "sperm competitors" - they produce huge quantities of sperm and likely mate with multiple females during each mating season. The testes of a male harbor porpoise normally weigh about 1/2 pound, but weigh more than a pound and a half during mating season.
The maximum known lifespan of a harbor porpoises is thought to be 20 years, although the average is thought to be 8-10 years.
Threats to harbor porpoises include interaction with fishing gear, pollution, noise and ship traffic. Entanglement of porpoises in gillnets have led to the formation of Take Reduction Teams for the Gulf of Maine and Mid-Atlantic, gillnet area closures, and the requirement to use "pingers" - acoustic deterrents - on gillnets.
References and Further Information:
- Bjorge, A. and K. A. Tolley, "Harbor Porpoise". In Perrin, W.F., Wursig, B. and J.G.M. Thewissen, Eds. 2002. Encyclopedia of Marine Mammals. Academic Press.
- Hammond, P.S., Bearzi, G., Bjørge, A., Forney, K., Karczmarski, L., Kasuya, T., Perrin, W.F., Scott, M.D., Wang, J.Y., Wells, R.S. & Wilson, B. 2008. Phocoena phocoena. In: IUCN 2012. IUCN Red List of Threatened Species. Version 2012.2.
. Accessed October 30, 2012.
- NOAA Fisheries: Office of Protected Resources. Harbor Porpoise (Phocoena phocoena). Accessed October 30, 2012.
- OBIS-SEAMAP. Harbor Porpoise - Phocoena phocoena. Accessed October 30, 2012.
- Perrin, W. 2012. Phocoena phocoena (Linnaeus, 1758). In: Perrin, W.F. (2012) World Cetacea Database. Accessed through: World Register of Marine Species. Accessed October 30, 2012.
- Wahlberg, M. . Harbor porpoise (P. phocoena). Society for Marine Mammalogy, Accessed October 30, 2012.