[ad_1]
In recent days, about 450 pilot whales, cetaceans of the dolphin family but up to seven meters long, have run aground on a beach on the island of Tasmania, south of Australia: 380 have died, about fifty have been rescued and returned to the sea, and about thirty are still stranded. It is one of the largest such episodes ever recorded and the worst in Australian history.
It happened in Macquarie Harbor, a shallow bay on the west coast of the island. Initially, only half of the pilot whales were sighted, stranded near the town of Strahan, but another 200 cetaceans were discovered about 10 kilometers away thanks to an aerial survey on Wednesday. They are likely to have entered the bay with the others, and are believed to be all dead. Even if they had been seen earlier, rescuers said, rescue operations would still have focused on the still-living pilot whales in the first group.
The approximately thirty specimens that were left alive on the beach are still being rescued, which before being returned to the sea were equipped with a small locator to keep them under control: pilot whales are actually social animals, and there is a risk that they will return to the group stranded once released. It has happened twice before, including those rescued at Macquarie Harbor.
Nic Deka, from the regional service that deals with natural parks and animals, said, however, that the focus is already on the elimination of the hundreds of dead pilot whales. The options are to put them in a landfill or take them out to sea and use ocean currents to push them out to sea. It is not possible to leave them where they are due to the strong odor that would cause their slow decomposition. Some sixty people, including state personnel and volunteer fishermen, are already gathering them into large nets.
The causes of stranding remain a mystery, as is often the case in these cases. Similar phenomena can depend on many factors, mainly natural and generally related to loss of orientation. They have always happened, especially with pilot whales, who live in large groups and have a very cohesive social structure. Over the years, theories have also been put forward linking strandings to man-made causes, such as the use of sonar by ships and rising sea temperatures, but there are still no real certainties. Kris Carlyon, a biologist with a marine animal conservation program, said “there is nothing to indicate that this stranding has human causes.”
We know that similar episodes occurred long before the presence of man, thanks to the fossil record that we have. Given that we have reliable evidence on the subject, it appears that the most extensive stranding of cetaceans occurred in 1918 in New Zealand, when 1,000 pilot whales died. In Tasmania, about 300 stranded in 1935, while before these days the most serious similar episode had involved more than 400 pilot whales at Farewell Spit, New Zealand, in 2017.
[ad_2]
