Wally, la gray whale spotted several times in recent weeks along the Tyrrhenian ridge and in the Ligurian Sea, it is a young specimen, of about 7.7 meters in length, most likely born in the Pacific in January last year. And it arrived as far as the Mediterranean after a long crossing of the Atlantic, where this cetacean has long been considered extinct. He was able to access it thanks to an ice-free passage in the Arctic Circle, this is the conclusion reached by the researchers of the scientific association. Tethys that thanks to a drone and telemetry measurements made with the Coast Guard they were able to accurately establish the size of the animal, which until now had only been measured “by eye”.
Size matters
The length is an important data, because it is essential to estimate the age. The migratory habits of gray whales are known and the combination of this knowledge has allowed scholars to answer questions about its origin. The area in which she was spotted during her most recent movements encompasses the whole Santuario Pelagos, enclosed between the Argentario, Liguria, Corsica and the Principality of Monaco, where cetaceans of at least eight species live, including whales and dolphins. But not the gray whale, which is currently only in the Pacific census. And that is why the sightings have aroused great interest in the scientific world. At the beginning it was assumed, but perhaps it is better to say hoped, that his presence could be a signal of return to the species also from this part of the globe. But everything suggests that the hypothesis of fortuitous transit is more probable.
Prolonged fasting
“The images from the drone made it possible to obtain a much more precise measurement – he explains Sabina Airoldi, project manager of Tethys, who was part of the team that operated -, comparing the whale with a boat that ran alongside it. The most accepted hypothesis now is that it is an individual of just over a year, probably born in the Pacific in January 2020“. A thesis on which they also agree Robert Brownell of the US National Oceanic and Atmospheric Administration e Jorge Urbàn Ramírez Autonomous University of Baja California, Mexico, involved in the evaluation of the case. “It is an individual a little smaller than the average – he adds Madalena Jahoda, researcher of the association -, who perhaps ate little during the long anomalous route from the Pacific to the Mediterranean. In line with this, the underwater images obtained yesterday confirm that he is extremely thin and this raises a lot of concern for his fate ».
Sightings in the Mediterranean
Wally has been in the Mediterranean waters since at least March, when the first sightings were recorded off the coast of Morocco andAlgeria. In April, it was revealed near the Italian coast: a Ponza, in Gulf of Naples, again in Lazio, at the mouth of the Tiber and then back up to Castiglione della Pescaia e Viareggio and, again, up to Sestri Levante and al Western Liguria. It has always fearlessly approached the coasts and certainly did not take care not to be noticed. “It is often an alarm signal for marine mammals, which when they are sick sometimes move to die on the beach – emphasizes Jahoda – but in this case it could also mean that it’s just trying to feed itself. In fact, gray whales have a peculiarity: they usually do not filter the plankton from the water, as for example the fin whales of the Mediterranean, but they sift small crustaceans and other animals from the mud, and they typically do so close to the shore, on the shallows ».
Risks along the way
Over the past two weeks, Wally has traveled further 800 kilometers moving in Italian waters, from Ponza to Imperia, where it was examined yesterday by Tethys. «Precisely this season it urgently needs to stock up on food – says Sabina Airoldi -: the hope is that it will be able to feed itself even in our unknown waters. It is therefore essential not to cause him further stress ». The Coast Guard is escorting the whale during its movements, also to prevent the risk of collisions with boats or one accidental capture in nets and other fishing gear, two of the dangers that usually run cetaceans living in the sanctuary, which is more so on paper than in reality given the intense tourist and commercial navigation activity. And a code of conduct has been issued for anyone who meets her offshore, with the recommendation of keep a distance of at least 100 meters, avoiding the gatherings of boats of onlookers (legitimate curiosity, given the exceptionality of the presence, but certainly not optimal for the animal). Also for this reason its position is not disclosed in real time.
The extermination of 700
The gray whale, scientific name Eschrichtius robustus, has long been present also in the Atlantic Ocean and probably also in the Mediterranean, according to the findings of some fossils from the Roman era. But in 700 the population was completely exterminated. There whaling it has long been a profitable business, conducted on a large scale, because the animals supplied not only meat but also and above all fat, from which an oil was obtained that was widely used in pre-industrial times as a fuel. A withdrawal so intense that in the end there is none left. But even on the other side of the world, where exploitation has been less intense, things are not better: there has been no extinction, explain from Tethys, but only the shoals that migrate along the American coast between Mexico and Alaska, where they stock up on food – this is probably another piece of Wally’s journey – have shown signs of recovery, while they continue to be abundant on the Asian side.
The first time in Italy
These days is the first sighting of this species in Italian waters; the only other in the Mediterranean dates back to May 2010 off the coast of Israel and, a few weeks later, near Barcelona. Only one animal has so far been documented in the Atlantic: it was in 2013, near the coast of Namibia. Even for these cases, certainly different, larger individuals, it was hypothesized that they had found an ice-free passage in the Arctic.
April 29, 2021 (change April 30, 2021 | 19:46)
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