The yacht Grazie Mamma II transported her crew along the coasts and archipelagos of the Mediterranean. Its latest adventure took place last week off the coast of Morocco when it encountered a pod of orcas.

The sea creatures struck the yacht’s rudder for 45 minutes, causing extensive damage and a leak. according to Morskie Mile, the Polish operators of the boat. The crew managed to escape and rescuers and the Moroccan navy tried to bring the yacht to safety, but it sank near the port of Tanger Med, the operator said on its website.

The report of the sinking adds to the concerns of many sailors on the west coast of the Iberian Peninsula, where marine biologists are investigating a mysterious phenomenon: Orcas jostle and ram boats in interactions that have disrupted dozens of trips and caused at least four boats decreased in the last two years.

Orcas, the largest of the dolphin family, are playful predators that hunt sharks, whales and other prey, but in general they are friendly to people in the wild. The orcas that hunt in the Strait of Gibraltar are considered such endangeredand researchers have noticed an increase in unusual behavior since 2020: A small group of the marine animals have attacked boats on busy routes around Portugal, Spain and Morocco.

While most interactions occur in the waters of southwest Europe and North Africa, An orca also reportedly rammed According to The Guardian, a yacht about 2,000 miles north off the coast of Scotland.

“Orcas are complex, intelligent and very social,” said Erich Hoyt, research associate at Whale and Dolphin Conservation and author of “Orca: The Whale Called Killer.” “We are still in the early stages of understanding this behavior.”

Researchers have rejected the idea that orcas attack ships. Instead, they suspect that boat oars have become toys for curious young orcas, and that the behavior has become a learned fad that has spread throughout the population. Another hypothesis, according to biologists who published a study A study of the population last June said ramming was an “undesirable behavior” due to a bad experience between an orca and a boat – although researchers tend to favor the former.

It’s unclear what will stop the ramming, playful or otherwise, a point that has led concerned captains traveling in these areas to share advice Facebook groups dedicated to tracking such interactions.

“It’s been an interesting summer hiding in shallow waters,” said Greg Blackburn, a Gibraltar-based skipper. Orcas crashed into a boat he was captaining in May and chewed on the rudder, he said, even though the ship was able to return to land.

The encounter left an impression: On a recent trip to Barcelona, ​​Mr. Blackburn had to cross an area where orcas had been spotted the week before. “I felt really sick for about three hours,” he said, “I kept watching the horizon for a fin to appear.”

Conservationists, sea rescue groups and yacht clubs are there We work together to overcome the challenge It’s about protecting a vulnerable population and helping seafarers avoid disaster. The Cruising Association, a club that supports sailors, has recommended safety protocols for orca encounters, such as turning off the boat’s autopilot and remaining silent. The captains have given each other anecdotal advice on deterring attacks, including throwing sand into the water and banging loudly on the boat.

Sailors can also seek advice before leaving the shore digital platforms which is now tracking reported orca sightings and interactions in the region. This can help them avoid the animals or find a route closer to shore, said Bruno Díaz López, a biologist and director of the Bottlenose Dolphin Research Institute based in Galicia, Spain.

“We suggested that the boats stay in shallow waters,” he said, adding that they noticed more boats changing their routes. “Maybe the journey will take longer, yes. But it’s worth it.”

Mr Blackburn, the captain, said he had heard of people throwing fireworks into the sea to scare away the animals, adding that the boats served as homes for people at sea. “What will you ultimately do if you protect your home?”

But the sea is home to orcas, and conservationists say scaring the animals away is not a solution.

“It’s not about winning a battle because this is not a war,” Mr. López said. “We have to be respectful.”