Burmeister’s Porpoise Project


Between 1998 and 2000, Fundación Cethus began a systematic study over three seasons on the presence of Burmeister’s porpoise in the Beagle Channel, Ushuaia, Tierra del Fuego. The main objectives were to carry out sightings in zones of the Channel where the species had been reported, to identify areas where long term studies and follow ups could be undertaken, in order to obtain data on the biology, ecology and behaviour of this rare and very little-known cetacean species.

Getting to know the Burmeister’s Porpoise
The Burmeister’s porpoise (Phocoena spinipinnis) is one of the six species of porpoise belonging to the Phocoenidae family. It exclusively inhabits the temperate surface waters of the coasts of South America, being endemic to the region. Its name is derived from “spina” for spine and “pinna” for fin, referring to the rows of small blunt tubercles in front of its small dorsal fin. Its common name in English refers to Hermann Burmeister who was the first to scientifically describe the species in 1865.

Physical characteristics
This species has the characteristically sturdy body of the porpoise with a conical head and no distinctive beak. Its back is usually dark grey with some variations towards dark brown.  The head, throat and stomach region is slightly paler with the exception of the eye which is surrounded by a dark patch. It differs from the rest of the phocoenids by the shape and position of its dorsal fin which is situated well behind the mid-back area, is small in size, and is very characteristic in being triangular. It presents 10-22 pairs of teeth in its upper jaw and 16-25 in the lower, the same shaped teeth as the other members of this family.
This species shows marked sexual dimorphism, the males being longer than the females.

Distribution
Although there are no precise details as to distribution, it is found only in South American waters and its distribution area is believed to extend from southern Brazil (28º-29ºS) on the Atlantic, up to the north of Peru (5ºS approx) on the Pacific, including Tierra del Fuego and Cape Horn.

Biology and Ecology
It is a species of mainly coastal habits although it is also found in open waters up to 60m in depth. They are nervous and timid in nature and usually swim rapidly without breaking the surface of the water. They are distinguished mainly by their backward-sloping dorsal fin situated in the rear third of its body and which does not exceed 6cm in height, and it is because of this that they often slip by totally unseen. Groups comprising two or three individuals are the most commonly observed. They rarely leap and show very little of their body when they come up to breathe, diving for between 1 and 3 minutes and swimming an erratic course usually avoiding any encounter with boats.
Because of its colouring and behaviour it is extremely difficult to spot in open water.
It mainly feeds on Fuegian spratt (Sprattus fuegensis), Argentine anchovy (Engraulis anchoita), squid (Loligo sp.), longtail hake (Macruranus magellanicus) and krill (Euphasia sp.).

Conservation
Some of the dangers this species faces, as with the majority of cetaceans, are being captured in fishing nets, over-fishing and pollution. It is believed that it is still caught for human consumption and for use as bait.
As it is a little-known species, and because of its distribution range, the IUCN considers there is insufficient information about it to correctly assess whether it is at risk of extinction based on it population status or distribution, therefore it is classified in the IUCN’s Red Book in the Data Deficient (DD) category. It is also included in Appendix II of CITES.