Those affected reported the first attacks by orcas on sailing boats in July 2020 in the Strait of Gibraltar. Then there were more killer whale attacks off Portugal and most recently off the northwest coast of Spain, in the Bay of Biscay. Which is obviously no coincidence, because the “crime scenes” are pretty much exactly on the migration route of the animals: In summer, orcas catch tuna off the coast of Andalusia, then they migrate past Portugal to the Galician coast – always chasing the prey.

Altogether there are about 50 orcas, 16 of which cause problems for the sailors. What could be behind the phenomenon? Thomas Käsbohrer compiled and tested all the theories currently under discussion for his new book “The Orcas’ Riddle”.

WORLD: How do sailboats up to 15 meters differ from boats that are 20 meters and longer?

Thomas Käsbohrer: Only in their dimensions, nothing else.

WORLD: Nevertheless, the orcas in the Strait of Gibraltar and in the Gulf of Cadiz mainly attack small and medium-sized boats. From this one could conclude that larger yachts are safe from orca attacks.

Käsbohrer: Whale protectors prefer to talk about interactions rather than attacks. And as for the larger boats, while they are safer because of the stronger construction, they are by no means immune to experiencing orca interaction.

WORLD: Have there already been attacks or interactions on larger boats?

Käsbohrer: Yes, a few even 35 meter yachts were attacked. However, about 80 percent of sailing boats between eight and 13 meters in length are actually affected. Catamarans account for the remaining 20 percent, followed by fishing boats, motorized inflatable boats and motor yachts.

WORLD: For your book you spoke to over 40 skippers who had unpleasant encounters with orcas. Many interviewees stressed that they personally did not feel threatened by the killer whales, but had the impression that the attacks were directed solely against the boat. It almost sounds as if the skippers wanted to protect the marine mammals.

Käsbohrer: In fact, many sailors said to me: “I don’t want you to write anything negative about the orcas.” However, there is not the slightest indication that the sailors are the orcas’ target, the animals always want to destroy the orcas oars. This was clearly visible on the cell phone videos. Because I chose my conversation partners according to whether they also have films of the interactions with the whales, because I wanted to compare the descriptions with the image material.

A sailor came very close to the animals; she was seasick and vomited at the stern just as an orca, only an arm’s length away from her, tried to tear away the rudder. It was a frightening situation – and yet she was sure that the orcas’ destructive actions were only aimed at the rudder and not at her and the other sailors on the boat.

WORLD: If big sharks attacked the boats, the skipper’s reaction would undoubtedly be different.

Käsbohrer: That may be the case, but orcas don’t eat humans and there is no evidence that an orca would have attacked a human in the wild, while shark attacks are rare but do occur.

WORLD: Orcas are at the top of the food chain in the sea. If they attack as a team, even blue whales don’t stand a chance. If orcas were to target a human, there would probably be nothing left of them. And since the animals are under protection almost everywhere, the contents of their stomachs rarely come to light. Why are you so sure that humans don’t have to fear orcas?

Käsbohrer: Whale experts and marine biologists that I was able to interview agreed that humans do not fit into the killer whales’ prey pattern. They basically never learned that humans could be their prey. What for? As you rightly said, orcas are extremely successful hunters in all oceans. Because the animals know how to adapt perfectly to their respective habitat by specializing in one or two prey groups.

Those orcas that live off the coast of Australia, for example, hunt 30-meter-long blue whales, off the southern tip of Africa they are after great white sharks, in the Antarctic the orcas have specialized in seals, which they get from ice floes or even from the beach. And the Orca group of 50 animals living off the Iberian Peninsula feeds mainly on tuna.

The Jaws has had a reputation as a merciless killer since the film classic of the same name at the latest. Orcas are apparently even more dangerous. New footage off the coast of South Africa documents an attack with an announcement.

Source: WORLD

WORLD: If there is no danger from the orcas, why does the Spanish coast guard explicitly advise the skippers to hide in the cabin during interactions?

Käsbohrer: The animals are not “frenzy”, as they say in English, not in a frenzy. They swim slowly towards the boats. But when they then use all their physical strength against the boat, turning it in circles or pushing it back and forth, finally diving down and trying to tear the oar away, no sailor can stop them – not with good persuasion and not with threatening gestures.

One of the people I interviewed tried to communicate with the killer whales; in his video you can see how he addresses the animals, how they react and actually become calmer. Nevertheless, the orcas also damaged his rudder system.

WORLD: Do the marine mammals follow a certain pattern in these interactions?

Käsbohrer: Almost all interactions that ended in rudder damage followed the pattern: approach, nudge boat, dive, damage rudder.

WORLD: It’s really strange that the orcas are so hot for oar blades. You talked about it with a lot of marine biologists and behavioral scientists…

Käsbohrer: … and really everyone gave a different answer. The range of explanations ranged from “Orcas want to disable the boats and prevent them from moving on”, to “Orcas nibble off the oars to practice tearing off shark, blue whale and tuna fins” to “infection-related or triggered by parasites Behavioral changes, since many pollutants accumulate in the animals over the course of a long orca life”.

WORLD: And the narrative of animal revenge, as described by Frank Schätzing in his bestseller “The Swarm”?

Käsbohrer: Not just Schätzing, think of Moby Dick and Captain Ahab! I checked the Moby Dick sources cited in the books and compared the descriptions with the current video material. I believe less in the motive of revenge as a common motive of the animals involved. In a team, the orcas are extremely willing to experiment, playful, varied and quite well planned, but not cold, calculating loners like Moby Dick.

I find Frank Schätzing’s theory more obvious, according to which the orcas could have “learned” their behavior under the influence of others. Marine biologists have found that mice infected with the parasite Toxoplasma gondii, i.e. suffering from toxoplasmosis, lose their natural fear of cats. Orcas could also have contracted the parasite from cat droppings in the harbor water and lost their fear of boats.

WORLD: To come back to the revenge theory: You yourself write in your book that orcas in the Strait of Gibraltar “occasionally interact in an aggressive manner with the boats of Moroccan fishermen” and damage them.

Käsbohrer: There are a lot of stress factors for orcas in the Strait of Gibraltar: the fight for the scarce resource of tuna, which orcas and fishermen alike are after, ship noise, extremely toxic industrial waste and a high risk of injury from ship propellers and fishing nets.

My own boat was mauled by a dolphin once in the middle of the night; he kept rubbing himself against my anchor chain. I couldn’t explain it at first until I discovered that someone had tied a rope around its tail fin, causing the animal excruciating pain. It was obvious that the dolphin was rubbing against the boat to get rid of the leash. But many apparent causal relationships are not so clear cut.

WORLD: Can you give an example?

Käsbohrer: Dolphins love to show tricks at a short distance in front of the running bow of a sailing yacht. I have often observed that during their artistic performances they regularly turn on their side and look up at me as if to say: “Look what I can do!”

But this behavior can just as well be a way of making sure that the one up there isn’t up to no harm. There can be many causes behind the behavior of marine mammals, and we know very few of them, I learned that during my research.

WORLD: And what else?

Käsbohrer: That the number of orca attacks will most likely continue to rise and that they will be more and more severe in terms of damage to the boats.

WORLD: I read in a sailing forum that sand poured into the sea next to the ship’s side could prevent orcas from interacting. Because the marine mammals avoid suspended matter in the water that could get stuck in their blowhole. The majority of sailors in the forum thought that scattering sand would be better than trying to drive the animals away with noise.

Käsbohrer: Whether with sand or noise – whale protectors reject human resistance as a matter of principle. According to my research, active resistance only seems to focus the animals more consistently on their goal. Marine biologist Renaud De Stephanis told me the Spanish government is giving him financial support to find out how to convert yachts so that killer whales can get off the helm.

I really hope he succeeds. Within two and a half years, between 400 and 500 steering gears were lost off the coast of Western Europe and two yachts were sunk. This emerges from the statistics of “Iberian Orca”, a newly founded initiative of researchers that documents the events. The problem can no longer be ignored, otherwise the affected sailors, fishermen and coastal residents will take matters into their own hands. Just like here, where the successful settlement of wolves obviously means that animals are shot “accidentally” more and more frequently.

WORLD: You are a skipper yourself. What did the research for the book do to you?

Käsbohrer: It’s like always when you get to the bottom of things. At the beginning of my journey I said: “I will not let my boat be demolished and I will defend myself”. Today I think that everything the orcas do is also related to each of us. That the orcas hold up a mirror to us. They do what they do because they can and because no one sets a limit to them. You are no different than us. But we humans are even more immoderate in our activities than they are. The orcas destroy yacht rudders. We are destroying the nature around us.

Before Thomas Käsbohrer made the sea his home, the historian managed a publishing house. And he still can’t stop reading books; in the last five years, the 63-year-old has published six travelogues and non-fiction books. In his recently published book he deals with the attacks of killer whales on boats:

Thomas Käsbohrer: “The Riddle of the Orcas. How orcas take back the sea. Why they attack boats”, Verlag millemari, Bibliothek der Extreme, 210 pages, 24.95 euros.