The spectacled porpoise gets its name from the dark circle surrounding its eyes. Little is known about this porpoise, and most knowledge has been collected from stranded animals. Despite the fact that the species is not often sighted at sea, biologists believe it to be more abundant than what is suggested. The markings of the robust body are very distinct, the top half is black and the bottom half is white. The dorsal fin is quite large and rounded and the length ranges from 1.3m-2.2m. Most sigthings are from the southern Atlantic coast of South America but confusingely enough, some records are from offshore islands which suggests that the species is curcumpolar in sub-Antarctic and low Antarctic waters. It has been seen off the cost of Brazil, the Falkland Islands, South Georgia, Auckland, Tasmania, south Australia, Heard Island and Kerguelen. The animal has rarely been observed in the open sea.
Every year around 2000 whales, dolphins and porpoises beach themselves, and little is known about why. Some species seem to be more inclined to strand in large numbers than others, and these are all toothed whales; sperm whales, pilot whales, killer whales, beaked whales and some oceanic dolphins. These species normally live in large, tightly knit groups and mostly in deep waters. Solitary species and those living in shallow waters are rarely victims of mass strandings.
When a single animal strands itself, it mostly has to do with it being injured or sick. Mass strandings, on the other hand, remains an unsolved mystery. It is believed that the strong social bonds between the whales might be a factor here, in the way that if one animal is in danger of stranding, the rest of the pod will follow it and subsequently beach themselves as well. Cetaceans have a complicated echolocation system and some scientists believe that the system may have difficulties detecting gently-sloping coastlines, so to the whales it might look as though they’re heading for open water.
If a beached animal doesn’t get back into open water again it might die from dehydration, drowning (if the tide covers the blowhole) or, for larger whales, by crushing its own organs due to its enormous weight.
If you ever come across a stranded cetacean, this is what you should do:
- Get expert help via the local police as quickly as possible, and while waiting for them:
- Keep the animal’s skin moist. - Erect a shelter to provide shade. - Keep the flippers and flukes cool. - Keep onlookers at a distance. - Make as little noise as possible. - Try to keep the animal upper side up.