Two porpoises approached us and we could even determine the sex of one of them.
The Burmeister’s porpoise inhabits the entire Chilean coast and has a beakless head like the Chilean dolphin. It can be distinguished easily by its backward-leaning dorsal fin that is also further back on the body (more than any other porpoise or dolphin) while the Chilean dolphin has a rounded dorsal fin. Burmiester's porpoises are incredibly difficult to spot at sea. They appear very dark and cause little disturbance of the water when they surface.
Attentive eyes can sometimes see the 2-7 rows of small tubercles that this porpoise has along the entire leading edge of its dorsal fin, hence it scientific name “spinipinnis” meaning spiny/thorny (“espinosa” in Spanish).
Can it be a sign that they are becoming more “human-friendly”? And would it be a good or a bad change for them? Since they are so susceptible to entanglement one would rather have them away from boats, but having them near allows scientists to gather more data from this elusive species.
In fact, this last time we could record some nice footage from the two porpoises that approached us and we could even determine the sex of one of them, an inquisitive female. Unfortunately we can't really identify the porpoises individually as we can with dolphins, because they don't seem to have the same stable and visible marks at their small dorsal fins.
We’ll see how the rest of the season goes and what more we can learn from them!
Herman Karl Burmeister, a famous German naturalist, was the first to ever describethe species in 1865, hence their name “Burmeister’s Porpoise”. At the time he was responsible for the Buenos Aires National Museum when the first specimen was collected from Río de la Plata.
According to IUCN Red List of Threatened Species the Burmeister’s Porpoise is a data deficient species, so its conservation status is still unknown. Based on sightings it seems that this porpoise is more abundant on the Pacific coast.
MORE INFORMATION ABOUT THIS SPECIES: http://www.yaqupachachile.com/#!burmeister-porpoise/c1jep
MÁS INFORMACIÓN SOBRE ESTA ESPECIE: http://www.yaqupachachile.com/#!marsopa-espinosa/c1qft
Bastida R., Rodríguez D. (2009) Mamiferos Marinos de Patagonia y Antartida (2nd Ed.). (pp 183-184). Buenos Aires: Vázquez Mazzini Editores.
Carwardine M. (2000) Porpoises. In Whales, Dolphins and Porpoises (2nd Ed.). (pp. 236-247). London: Dorling Kindersley.
Hammond, P.S., Bearzi, G., Bjørge, A., Forney, K.A., Karkzmarski, L., Kasuya, T., Perrin, W.F., Scott, M.D., Wang, J.Y. , Wells, R.S. & Wilson, B. (2012). Phocoenaspinipinnis. The IUCN Red List of Threatened Species. Version 2016.1. <www.iucnredlist.org>.
Shirihai H., Jarret B. (2006) Porpoises – Burmeister’s Porpoise. In Whales, Dolphins and Seals – A Field Guide to the Marine Mammals of the World (pp. 255-257). London: A&C Black Publishers.