Sharks on the Catalan coasts: are there more now?

BarcelonaIn July 2023, in Portbou, two fins made an appearance on the beach, very close to the sand, and swimmers didn't think twice. Some swam quickly towards the shore. Shouts and nerves. Others, about fifteen, opted to temporarily take refuge on a large platform floating in Portbou bay. The scare was significant: they were two blue sharks, popularly known as "tintoreras," calmly swimming near the beach. Some bathers even managed to record the two specimens from the sand. And once again, the videos went viral on social media.

It is not the first time that sharks have been spotted off the Catalan coast this summer. At the end of June of the same year, the Alcanar City Council, in Tarragona, also ended up closing the Martinenca, Maricel and Marjal beaches to bathing due to the presence of two sharks, which led to the red flag being raised. In 2024, they were also spotted in El Masnou and, in 2025, on Arrabassada beach in Tarragona. In fact, practically every summer, some of these specimens are seen on the Catalan coasts. But, are there more now than before? Are they attracted by the high temperatures and warmer waters?

The biologist from Empordà, Josep Maria Dacosta, assures that not.Quite the opposite."We come from years of overfishing and now the fish on the coast is small and scarce", a scenario that has also affected sharks as part of the ecosystem, assures Dacosta. "The appearance of two blue sharks is absolutely occasional and does not mean there are more," he assures. "In fact, it is good news, because it means that the Mediterranean Sea remains alive in a very complicated global change scenario, with less rain, and therefore less organic matter reaching the sea; higher water temperatures, and a thousand and one recreational activities that pollute the sea," he adds.

From the Wildlife and Flora Service of the Generalitat de Catalunya, biologist Santiago Palacios agrees. "They are not attracted by the warm waters, because this type of fish lives in the open sea. If any reach the coast, it is because they are young, disoriented, injured, or sick; they are out of their habitat and in no case are they looking for prey," he states. According to the two experts, the perception that "there are more of them now" is a consequence of the viralization of these videos. "Social networks turn what a few years ago was a conversation among fishermen into a global spectacle," jokes Dacosta.

How to act

Blue sharks or tope sharks (Prionace glauca), which are the most common to see in the Mediterranean near the coast, are a type of cartilaginous fish that measures between one and a half and three meters long. They have rough skin and, as a general rule, do not attack people. They feed on other smaller fish and cephalopods, such as squid, and also crustaceans. "If they are spotted, what must be done is to remain calm and keep in mind that they are not toys: do not approach them, do not disturb them, do not corner them," explains Dacosta. "There are animals that are curious by nature and might approach simply to look: if we stay still, they will surely do nothing, they will swim by and leave," he insists. The best thing, he points out, is not to shout and to move discreetly towards the coast.

Once out of the water, the most appropriate thing would be to inform the lifeguards, agrees Palacios. "They are the ones who will decide if the beach needs to be evacuated and will call the appropriate authorities," adds this biologist from the Department of Climate Action. "If necessary, the authorities will send a boat to examine the specimens and redirect them further out to sea," he explains. In the event that there is no lifeguard on the beach, bathers can inform via the emergency telephone number 112.

Currently, there is no official census of the sharks that inhabit the Mediterranean Sea. "There have always been sharks and not just dogfish – admits Palacios–. White sharks also live in the Mediterranean, which are more aggressive, for example". "Although there are now research institutes that are beginning to conduct studies, we cannot know exactly if there are more sharks now than before, because there are no records from 10 or 20 years ago", admits the expert. What does seem evident, according to the two biologists, is that it is most likely that overfishing has caused their population to decrease.

Therefore, faced with a sighting like these, Dacosta is clear: "Once we are in a safe place where we don't bother them, the best we can do is enjoy them: they have a beautiful blue color and a hydrodynamic shape", he concludes.