In 2024, almost 700 animals were stranded on the Galician coast. The figure is at this level, which triples the average of the last three decades, for the second consecutive year. What is most abundant are cetaceans and, within these, the weight and increase of common dolphins is striking —common urchinsin Galician. In addition to the strong increase, another change has occurred: there is a peak in the months of July and August, so marked that in that period the records of the months that traditionally accumulated the most strandings, which were January, February and March.
“The jump is so enormous that we don’t know how to explain why,” says Pablo Covelo, biologist at the Coordinator for the Study of Marine Mammals (Cemma). This organization, financed by the Biodiversity Foundation, of the Ministry for the Ecological Transition, and the Xunta de Galicia, is the one that takes care of the specimens that appear on the Galician coast. The recently published balance for 2024 shows that 689 animals were stranded, including cetaceans, seals, turtles, sharks and otters. In 2023 they counted 697 and in 2022 there were 313. Covelo remembers that since they started working, in the 90s, the average was about 240 per year among cetaceans, seals and turtles. “The numbers from recent years are scary,” he says.
The biologist says that experts do not have an explanation for what is happening. When the bodies that arrive are not in poor condition, the samples taken from them rule out a specific disease that is affecting them. He explains that what is found are “expected” problems in wildlife and that they are specific to each individual: a spleen or heart problem or parasites in the lungs. Of the specimens that reach the coast – it is normal for the animal to die at sea and be dragged to shore by the winds and currents – around 60% are in a state of moderate or advanced decomposition and information can be obtained limited.
In the sea, says the expert, “something is happening.” He relates it to the search for food by cetaceans: “They have less food or they come to look for it more along the coast.” He gives the example of common dolphins, with increasing strandings and a habitual pattern: they enter to the bottom of the estuaries, despite the fact that it is a species that was rarely introduced into those waters, and, as they are not used to the tides, they They become trapped when the water level drops. In these cases, Cemma is usually able to care for the animals, which are alive. It is necessary to hydrate them and refloat them so that they return to the open sea. “What has been happening in recent years with this species is very strange,” he says.
“This is a manifestation that something is happening. Why do they now go to the bottom of the estuary to eat?” he reflects. Covelo points out that what is happening is “surely” some change in the food chain and, “as cetaceans are the last link” the effects on them can be seen. “We still don’t know how to interpret it reliably; “We would have to gather data from other branches that we do not have, such as oceanographic or fisheries data,” he adds.
Covelo remembers that not all animals that die at sea reach the coast. An experiment carried out years ago with the fishing sector suggests that around a quarter of them appear on beaches and rocks. That study was based on accidental captures – the main cause of death of cetaceans in Galicia – from fishing boats that fish near the coast. Several skippers collaborated to put an identifying bridle on the cetaceans that died in their nets and thus return them to the sea in the area where they had been captured. The biologist emphasizes that, if the current figure had to be multiplied by four, it would be “spooky.” But another hypothesis is that, if cetaceans get closer to the coast in search of food, it is also possible that, due to the proximity, their corpses appear in a percentage higher than the 25% calculated.
Dolphins, sharks, porpoises
Data from 2024 show that most of the stranded animals are cetaceans: 614 out of 689. Among these, the most frequent were common dolphins, with 455 cases. Below are the rice -bottlenose dolphin-, with 46 individuals; the striped dolphins, with 18; and the toniñas -porpoises-, with 14. The latter is a species in danger of extinction, one of the many for which the Xunta has not developed a recovery plan. There are also six whales of different types.
In addition to cetaceans, in 2024, 14 otters – a native species that is increasingly widespread on the coast -, 23 sharks and 32 turtles, arrived on the Galician coast. Among the latter, Covelo explains that the most frequent were the common turtles, which are born in the Caribbean and reach the other side of the Atlantic when they are still small and measure around 20 centimeters – they reach a meter. The biologist explains that it is easy to get them through with hot water and food. They usually suffer from respiratory problems and 95% have plastic in their stomach, although this is not an immediate risk to their life. “They are usually small pieces that they ingest thinking they are food and they eliminate them,” he points out. Another issue, currently being studied, is the possible toxicity of these plastics and their additives.
Plastics are a widespread problem in the oceans. According to Covelo, over 90% of small cetaceans have microplastics. The origin is usually the animals that eat in the sea. In the case of deep-diving cetaceans, such as the sperm whale or the beaked whale, cases of deaths due to intestinal obstruction have been found due to ingesting large plastics.
As for the seals, the biologist indicates that last year there were few (six) and none needed care. They were, he says, sightings on beaches of animals that had probably come out of the sea to sleep. In fact, Covelo explains that the problem with seals is that people are surprised when they see them and, out of ignorance, try to encourage them to return to the water, when what these specimens are looking for is to rest.
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