Burmeister's Porpoise
Encyclopedia
Burmeister's Porpoise is a species
of porpoise
endemic to the coast of South America
. It was first described by Hermann Burmeister
, for whom the species is named, in 1865. Locally it is known as marsopa espinosa (thorny porpoise) and chancho marino (sea pig).
in the Pacific
round Tierra del Fuego
and up to southern Brazil
in the Atlantic
. The total population is at least in the tens of thousands. While usually described as staying very close to the shore, individuals have been spotted as far as 50 km from the shore and in the freshwater Valivia River in southern Chile
.
is unusual for a cetacean—it is triangular rather than curved and points backwards more than upwards. It is located about three quarters of the way along the back—further back than any other dolphin or porpoise. These features are sufficient to distinguish the porpoise from the similar-sized Chilean Dolphin
which is found in the porpoise's Pacific range.
such as anchovies
, hake
and mackerel
.
, Peru
and Chile
. The annual estimated catch is largest in Peru, at 2000 individuals [5]. Burmeister's are also harpooned deliberately for food and for use as shark bait.
In severe El Nino events, the ecosystem of the Humboldt current
is disrupted. Anchovies either perish or leave the area, and it appears that many porpoises and other marine mammals starve as a result.[6]
The IUCN lists the animal as data deficient in its Red List of Threatened Species. The long-term prognosis for the species is unknown.
The Burmeister's porpoise is listed on Appendix II of the Convention on the Conservation of Migratory Species of Wild Animals (CMS
). It is listed on Appendix II as it has an unfavourable conservation status or would benefit significantly from international co-operation organised by tailored agreements.
Species
In biology, a species is one of the basic units of biological classification and a taxonomic rank. A species is often defined as a group of organisms capable of interbreeding and producing fertile offspring. While in many cases this definition is adequate, more precise or differing measures are...
of porpoise
Porpoise
Porpoises are small cetaceans of the family Phocoenidae; they are related to whales and dolphins. They are distinct from dolphins, although the word "porpoise" has been used to refer to any small dolphin, especially by sailors and fishermen...
endemic to the coast of South America
South America
South America is a continent situated in the Western Hemisphere, mostly in the Southern Hemisphere, with a relatively small portion in the Northern Hemisphere. The continent is also considered a subcontinent of the Americas. It is bordered on the west by the Pacific Ocean and on the north and east...
. It was first described by Hermann Burmeister
Hermann Burmeister
Karl Hermann Konrad Burmeister was a German zoologist, entomologist, and herpetologist.Burmeister was born in Stralsund and became a professor of Zoology at the Martin Luther University of Halle-Wittenberg from 1837 to 1861...
, for whom the species is named, in 1865. Locally it is known as marsopa espinosa (thorny porpoise) and chancho marino (sea pig).
Population and distribution
While Burmeister's Porpoise seems to be relatively common in its range, little work has been done to survey the species. Its range appears to be continuous in coastal waters from northern PeruPeru
Peru , officially the Republic of Peru , is a country in western South America. It is bordered on the north by Ecuador and Colombia, on the east by Brazil, on the southeast by Bolivia, on the south by Chile, and on the west by the Pacific Ocean....
in the Pacific
Pacific Ocean
The Pacific Ocean is the largest of the Earth's oceanic divisions. It extends from the Arctic in the north to the Southern Ocean in the south, bounded by Asia and Australia in the west, and the Americas in the east.At 165.2 million square kilometres in area, this largest division of the World...
round Tierra del Fuego
Tierra del Fuego
Tierra del Fuego is an archipelago off the southernmost tip of the South American mainland, across the Strait of Magellan. The archipelago consists of a main island Isla Grande de Tierra del Fuego divided between Chile and Argentina with an area of , and a group of smaller islands including Cape...
and up to southern Brazil
Brazil
Brazil , officially the Federative Republic of Brazil , is the largest country in South America. It is the world's fifth largest country, both by geographical area and by population with over 192 million people...
in the Atlantic
Atlantic Ocean
The Atlantic Ocean is the second-largest of the world's oceanic divisions. With a total area of about , it covers approximately 20% of the Earth's surface and about 26% of its water surface area...
. The total population is at least in the tens of thousands. While usually described as staying very close to the shore, individuals have been spotted as far as 50 km from the shore and in the freshwater Valivia River in southern Chile
Chile
Chile ,officially the Republic of Chile , is a country in South America occupying a long, narrow coastal strip between the Andes mountains to the east and the Pacific Ocean to the west. It borders Peru to the north, Bolivia to the northeast, Argentina to the east, and the Drake Passage in the far...
.
Physical description
Most photographs of Burmeister's Porpoises are taken of dead specimens and show the animal to be coloured black. This phenomenon gave rise to the earlier common name, the Black Porpoise. However live individuals are typically a dark grey color. They turn black in just a few minutes after death. The underside varies in colour but is usually a lighter grey. Burmeister's are about 150 cm long when fully mature and weigh 50–75 kg. The maximum recorded weight is that of a female at 105 kg. They have a shallow indentation at their blowhole set just in front of the eyes. The shape and placement of the dorsal finDorsal fin
A dorsal fin is a fin located on the backs of various unrelated marine and freshwater vertebrates, including most fishes, marine mammals , and the ichthyosaurs...
is unusual for a cetacean—it is triangular rather than curved and points backwards more than upwards. It is located about three quarters of the way along the back—further back than any other dolphin or porpoise. These features are sufficient to distinguish the porpoise from the similar-sized Chilean Dolphin
Chilean Dolphin
The Chilean Dolphin , also known as the Black Dolphin, is one of four dolphins in the Cephalorhynchus genus. The dolphin is only found off the coast of Chile, it is commonly referred to in the country as Tunina....
which is found in the porpoise's Pacific range.
Behaviour
Burmeister's Porpoise is difficult to observe. It appears to be shy, shows little of its body when surfacing and will move quickly away from approaching boats. They are typically seen alone or in pairs with occasional larger groups. One report from Chile saw a group of 70 in number. The porpoise feeds on various pelagic fishPelagic fish
Pelagic fish live near the surface or in the water column of coastal, ocean and lake waters, but not on the bottom of the sea or the lake. They can be contrasted with demersal fish, which do live on or near the bottom, and reef fish which are associated with coral reefs.The marine pelagic...
such as anchovies
Anchovy
Anchovies are a family of small, common salt-water forage fish. There are 144 species in 17 genera, found in the Atlantic, Indian, and Pacific Oceans. Anchovies are usually classified as an oily fish.-Description:...
, hake
Hake
The term hake refers to fish in either of:* family Phycidae of the northern oceans* family Merlucciidae of the southern oceans-Hake fish:...
and mackerel
Mackerel
Mackerel is a common name applied to a number of different species of fish, mostly, but not exclusively, from the family Scombridae. They may be found in all tropical and temperate seas. Most live offshore in the oceanic environment but a few, like the Spanish mackerel , enter bays and can be...
.
Conservation
Like all porpoises, Burmeister's is vulnerable to accidental capture in fishing nets. This is common in UruguayUruguay
Uruguay ,officially the Oriental Republic of Uruguay,sometimes the Eastern Republic of Uruguay; ) is a country in the southeastern part of South America. It is home to some 3.5 million people, of whom 1.8 million live in the capital Montevideo and its metropolitan area...
, Peru
Peru
Peru , officially the Republic of Peru , is a country in western South America. It is bordered on the north by Ecuador and Colombia, on the east by Brazil, on the southeast by Bolivia, on the south by Chile, and on the west by the Pacific Ocean....
and Chile
Chile
Chile ,officially the Republic of Chile , is a country in South America occupying a long, narrow coastal strip between the Andes mountains to the east and the Pacific Ocean to the west. It borders Peru to the north, Bolivia to the northeast, Argentina to the east, and the Drake Passage in the far...
. The annual estimated catch is largest in Peru, at 2000 individuals [5]. Burmeister's are also harpooned deliberately for food and for use as shark bait.
In severe El Nino events, the ecosystem of the Humboldt current
Humboldt Current
The Humboldt Current , also known as the Peru Current, is a cold, low-salinity ocean current that flows north-westward along the west coast of South America from the southern tip of Chile to northern Peru. It is an eastern boundary current flowing in the direction of the equator, and can extend...
is disrupted. Anchovies either perish or leave the area, and it appears that many porpoises and other marine mammals starve as a result.[6]
The IUCN lists the animal as data deficient in its Red List of Threatened Species. The long-term prognosis for the species is unknown.
The Burmeister's porpoise is listed on Appendix II of the Convention on the Conservation of Migratory Species of Wild Animals (CMS
Bonn Convention
The Convention on the Conservation of Migratory Species of Wild Animals aims to conserve terrestrial, marine and avian migratory species throughout their range...
). It is listed on Appendix II as it has an unfavourable conservation status or would benefit significantly from international co-operation organised by tailored agreements.