At least 15 whales have been found dead in the last 10 days off the coast of Chubut province, 1,400 kilometers south of Buenos Aires. The first was found floating on September 24 in Punta Pardelas, at the entrance to the Valdés Peninsula, a gulf that encompasses six natural areas where the southern right whale reproduces and gives birth during the austral spring. Scientists have not yet found the cause of death. According to a report by the Whale Conservation Institute (ICB), which is responsible for monitoring its population on the Argentine Patagonian coast, the unusually high number of dead whales in a short period of time “may be an indicator of local environmental variables.”
Researchers’ main hypothesis is that the deaths could have been caused by red tide, an unusually high bloom of toxic algae in a given area. The ICB assumes this hypothesis as one of the main ones after warning that none of the whales that they have been able to evaluate until this Thursday shows evidence of injuries. “All were found to be in very good nutritional status, with evidence of intestinal content in some specimens, indicating their recent feeding within the gulf,” says the coordinator of the field program, Agustina Donini, in the institution’s statement.
Chubut has experienced days of alarm over the presence of toxic algae on the peninsula in the last week. This Tuesday, the Provincial Directorate of Environmental Health of the provincial government raised a four-day alert in which it asked the population to avoid consuming the drinking water in the area for fear that the toxins have been filtered by the desalination plant that takes water from sea. The deaths have put the Chubut government on alert, which has already intervened in the investigation and awaits studies on other species after ruling out high levels of toxins in drinking water. “Until now, removing some penguins whose studies must be determined, there are no other species affected or reported,” explained the province’s director of fauna, Fernando Bersano, in a radio interview.
Whale deaths in the area are not unusual, especially during mating season. According to the ICB report, 45 mammals were found dead in 2021 on the same coasts, but, as explained by the institute’s scientific director, Mariano Sironi, “although the number of dead adult whales this season is still less than the season past, it is worrying that the deaths have been recorded in such a short period of time.”
The southern right whale, protected in Argentina as a National Natural Monument, is one of the main tourist attractions in the area. An adult whale can measure up to 16 meters, and its curious nature that brings it closer to the surface means that its sighting is not uncommon on the Argentine coast during this time. It is a species that has managed to recover from extinction after a century of commercial hunting. Inhabitant of the southern seas, its sighting is also common in Chile, Uruguay, South Africa, Australia, New Zealand. A third of its world population – which is estimated at around 6,000 specimens – comes each year between April and December to the protected bays of the Valdés Peninsula, where the calm and warmth of the water is ideal for them to give birth. and mate. The Whale Conservation Institute recorded 1,420 whales off the Patagonian coast just a month ago, the highest number since it began counting them in 1971. Despite having avoided extinction, the southern right whale is still a vulnerable species: its period Gestation lasts almost three years and, although hunting is prohibited, plastic garbage, maritime traffic and the effect of global warming on the crustaceans that serve as food are a permanent threat.
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