Spain has ordered small boats to steer clear of a stretch of the country’s southern coast after reports of more than 50 encounters with boisterous orcas, including as many as 25 incidents in which boats had to be towed to shore. A two-week prohibition bars most vessels of 15 metres or less from sailing near the coast between Cape Trafalgar and the small town of Barbate. It is the second time in 13 months that Spain’s ministry of transport has taken action to address a spate of extraordinary orca encounters that have baffled scientists. Last year’s ban applied to an area several hundred miles north. At the time the ministry said the measure was prompted by the orcas involvement in “several incidents in the coastal area of Galicia, mainly involving sailboats”. Authorities did not release the exact figure of how many boats had been affected. The most recent order was aimed at preventing “further incidents with orcas” the ministry said in a statement. “Since 27 March – the date of the first encounter [this year] – the cetaceans have had 56 interactions with small sailboats, at times causing rudder failure. Up to 25 cases required the services of Spain’s maritime rescue to tow vessels into port.” The order to give the area a wide berth came one day after three separate encounters with orcas were reported in the area within five hours. Two of the vessels suffered damage to their rudders and had to be towed into port, according to Spain’s maritime rescue service. Reports of run-ins with the highly sentient cetaceans along the coast of Spain and Portugal began surfacing in July and August of last year, with sailors sharing stories of rudders that had been rammed and boats that had been spun 180 degrees or tipped sideways. Describing the behaviour as highly unusual, scientists have struggled to explain the encounters. “These are very strange events,” cetacean researcher Ezequiel Andréu Cazalla told the Guardian last year. “But I don’t think they’re attacks.” Scientists have been cautious in characterising the encounters, given that the accounts have not come from trained researchers. Several of the scientists pointed to the stress on the endangered Gibraltar orcas as they navigate life in a major shipping route. Food scarcity, injuries and pollution have left the population on a knife’s edge, reduced to fewer than 50 individuals. The timing of the encounters, which appeared to begin as marine traffic picked up after two months of reduced noise during the pandemic, has led one marine biologist to speculate that the orcas could be expressing anger as big game fishing, whale watching and fast ferries returned to the water. Others have linked the encounters to several rowdy orcas who may have gotten carried away while playing. “We’re not their natural prey,” Bruno Díaz, a biologist at the local Bottlenose Dolphin Research Institute, told the Associated Press last year. “They’re having fun – and maybe these orcas have fun causing damage.” In October a working group of Spanish and Portuguese experts said it had identified three orcas present in 61% of incidents and suggested that the “unprecedented” behaviours may be linked to an earlier “aversive incident” between the orcas and a vessel. “For the moment, we have no clear evidence of when it happened, nor can we say for sure what kind of boat may have been involved, nor whether the incident was accidental or deliberate,” it noted in a statement.