Dolphin Species: Spectacled Porpoise
Phocoena dioptrica

Distribution and Habitat
Spectacled porpoises are found only in the temperate and sub-Antarctic waters of the Southern Hemisphere. Although the distribution of spectacled porpoise in these waters is beleived to be circumpolar in nature (see map), reliable sightings have only been made at these locations: Heard Island, Kerguelan Island, Macquarie Island, South Georgia, the Falkland Islands and Tierra del Fuego. Spectacled porpoises appear to prefer cold (5.5 ° C to 9.5 ° C), open oceanic waters.

Natural History
Spectacled porpoises are uniform black on their dorsal and dorso-lateral surfaces which are separated from the lighter ventral and ventro-lateral surfaces by a distinct line. They have a black eyepatch which is usually outlined with white, providing the basis for their common name (derived from the Greek word diopter = spectacled). The dorsal fins of spectacled porpoises are triangular in shape and are greatly enlarged in males. Males are, in general, larger than females. Very little is known about the ages of sexual maturity for this species; based on a very small sample size it has been estimated at around 4 years for males, and 2-3 years for females. Almost nothing is known about the food preferences of spectacled porpoises. A single stranded animal in Argentina had anchovy and small crustaceans in its stomach.

Status and Protection
There are no abundance estimates available for spectacled porpoises and IUCN lists it as a Data Deficient species in the Red List of Threatened Species.

Threats to the Species
Spectacled porpoises are taken in some fisheries including gillnet fishereies in Tierra del Fuego and southeastern Chile. They are also taken in some bottom and mid-water trawls in Argentina. The magnitude of the above listed bycatch is not well documented.

Sources
Brownell Jr., & Clapham, P.J. 1999. Spectacled porpoise (Phocoena dioptrica) In S.H. Ridgeway & R. Harrison [eds.], Handbook of Marine Mammals, Volume 6: The Second Book of Dolphins and Porpoises. Academic Press. San Diego.

Jefferson, T.A. et al. 1993. Marine Mammals of the World. FAO Species Identification Guide. United Nations Environment Programme. Rome.

Perrin, W.F., Donovan, G.P. and Barlow, J. 1994. Gillnets and Cetaceans. Report of the International Whaling Commission, Special Issue 15. Cambridge.