The rocky beach of El Calafín, in the state of Baja California Sur, became a graveyard for dolphins on May 25.
Elements of the Federal Attorney for Environmental Protection ( Profepa ), in coordination with the Network of Attention to Stranding of Marine Mammals, went to the beach located about 40 kilometers north of the city of La Paz after receiving reports of the dead dolphins.
There they counted at least 30 specimens out of the water; None showed visible marks of blows or tears, so an attack by killer whales or other marine predators was ruled out as the cause of death, according to Francisco Javier Gómez, leader of the mammal rescue operations in the lower part of the peninsula.
"Almost three dozen corpses were counted, 27 in that area and three more a couple of kilometers from the place."
He pointed out that most of them reached the shore lifeless or in very poor condition for more than 48 hours, although there is no report of a red tide in the waters of Baja California Sur.
“The death did not occur in the area, the theory is that the currents washed them to the area. When live animals are stranded, they are all fresh, here some of them do not even have their eyes […] The vast majority of dolphins show signs of having a few days without life, however, it is possible that a couple of them have less than 24 hours of death."
Faced with the mystery, the authorities decided to transfer the freshest specimens to the laboratories of the Museo de La Ballena in order to perform an autopsy to determine the cause of death. So far, neither Profepa nor the Ministry of the Environment and Natural Resources ( Semarnat ) have ruled on the matter.
This is not the first time that dolphins have been found stranded on a beach in the region. In 2017, about 50 dolphins were recorded on Pichilingue beach, 60 kilometers east of El Calafín. However, on that occasion, the vast majority of organisms were able to be returned to the sea alive.
According to environmental authorities, there are various causes for the stranding of these animals, which can be natural ( due to old age, intoxication, predators, or environmental factors) or anthropic (entanglement in nets, pollution, oil spills, or capture).
The common dolphin is a gregarious mammal that can live in colonies of up to 500 specimens, measures between 1.7 to 2.4 meters, and can weigh between 70 and 110 kilos.
