In the past few days, at least six orcas have been stranded on the coasts of Mar del Plata, Argentina, two of which died despite the efforts of rescuers and experts to save them. The marine specialists do not have a clear explanation of the phenomenon that surprises by the amount of stranded specimens in such a short time.
Scientists have already warned that the extinction of different types of whales is increasing, not only by the indiscriminate hunting of these but by the strandings. In the past, they happened in Australia and South Africa, but for some time, they have occurred on any beach.
One of the most alarming cases of massive stranding occurred in 2009, on the beach of Naracoopa, Australia’s King Island, where 200 pilot whales were stranded.
Although what happened on the beaches of Argentina cannot be considered a massive stranding, specialists agree that the succession of strandings is at least striking.
To investigate, before returning them to the sea, the scientists of the Aquarium Foundation have taken blood and fat samples to learn about the reasons that led them to run aground on the beach.
The chronology of the stranding of the last days
The first stranding was reported two weeks ago, to the Rescue Center of the Mundo Marino Foundation. It was near the coast, at Punta Rasa, at the southern end of the Bay of Samborombón, there was a stranded marine animal. It was a young humpback whale almost 10 meters long. He was in a swampy area of very strong winds and had a fishing net tangled in his caudal fin that forced him to keep 70% of his body out of the water. It was rescued and returned to the open sea.
A second call occurred on August 24, reported three orcas stranded on the beaches of Nueva Atlantis, 50 kilometres from San Clemente del Tuyú. When the rescue team of the Mundo Marino Foundation came to her aid, she found one animal in a critical situation and another died. Rescuers worked for almost 20 hours at very low temperatures to return the sea to which they still had life.
The third warning, according to speculation, is about another specimen that appeared dead on the beaches of Villa Gesell.
On the morning of Sunday, August 26, two other young specimens were rescued near the coast of Mar del Plata: one in Punta Mogotes and another in the port that the Prefectura boats took to the open sea, by the Aquarium and Prefectura Foundation.
During the rescue of the orcas, there were several difficulties. The low waves and the low tide made the work difficult and delayed the return of the orcas to the sea, but fortunately, they managed to return four to the waters.
Possible causes of strandings
The marine biologist Alejandro Saubidet, scientific director of the Oceanarium Aquarium of Mar del Plata, says that this type of grounding is common and believes that it is unlikely that these six cases are due to global warming, pollution or any influence of man.
Aminta Jauregui Romero and Nataly Morales Rincon, professors and researchers from the Jorge Tadeo Lozano University, explained that the leader, who is usually a male, directs the entire herd, but if he is sick or disoriented he can lead the group to his death. There may also be the possibility that, due to climate changes and the variation of tidal movement, changes will be generated in the coastal topography, turning some areas into muddy sandbanks.
“Other causes can be due to the echolocation confused possibly to other emitters of noise that distort the path affecting the wavelength so that it can be interpreted by the animal. On other occasions stranding occurs due to the monitoring of old migratory routes that for some reason no longer exist, “the researchers affirm.
Sea pollution could also affect because waste and chemicals when ingested, can intoxicate and lead to disorientation.
There are those who believe that military radars and sonars emit signals that whales can follow. In addition, maritime traffic could also be changing its routes.
We must wait for the results of the examinations taken by the team of researchers, to have a light about the possible causes.
Source: BL es Mundo