In late August fishermen in the Gibraltar Strait reported some strange and aggressive activity from pods of orcas. These have continued to happen over the last two months, and now researchers believe there are killer whales orchestrating revenge attacks from altercations back in June. (1)
Killer Whales Orchestrating Revenge Attacks
Scientists believe that the killer whales orchestrating revenge attacks on fishing boats and yachts are doing so because of injuries they sustained from rudders back in the summer. Crews sailing in the Galicia region of Spain reported 22 attacks since August 10. While no one has gotten hurt, the orcas have done severe damage to many of the boats. (1)
Three Main Orcas Identified
The Spanish and Portuguese scientists used underwater photography and video footage to identify three whales that have been involved in 61% of the attacks. Each of these whales, nicknamed Black Gladis, White Gladis, and Grey Gladis, are showing wound marks. The researchers believe they sustained these wounds between June and August. (1)
The wounds may have occurred while trying to take tuna off of fishing lines, but they also could be from accidental contact with the boats. (1)
Speed May Have Been a Factor
As of now, the researchers don’t have clear evidence as to what exactly happened and what type of boat was involved, however, they believe that speed may have been a factor. (1)
“The trigger for this strange and novel behaviour could have been an aversive incident that the orcas had with a boat, and in which the speed of the boat could have been a critical factor,” they said in a statement. (1)
After the incident, they believe the orcas may have felt compelled to attack the rudders of boats in order to slow them down so that no other members of their pod would get hurt. This is why they have been specifically attacking the boats’ rudders. (1)
A Ban on Boats
Spanish maritime authorities banned boats less than 15 meters long from the strait for one week at the end of September. The purpose of the ban was to keep small, more easily damaged boats out of the strait while the orcas make their annual trip up the gulf in pursuit of tuna.
Not Just Boats
Over the last three years, orcas in South Africa have been attacking great white sharks at an alarming rate. The pods are ripping the sharks open just below the throat so that their nutrient-rich livers, hearts, and other organs will just slide out. (2)
Seven gill sharks in the area were killed in the same manner. Scientists linked the attacks to two orcas in the area, who performed these attacks in a very precise and deliberate way. (2)
“Just under the surface of the skin is the perfect place to open up the shark and access and extract the liver. I think two of the animals had both the heart removed and one male had his testes removed. Because they’re very close there in the body cavity.” says marine biologist Allison Towner. “We think the two killer whales were learning to get hold of the pectoral fins. We don’t know for sure. It’s like a ripping motion. The liver … it’s oily, very slippery, it would naturally slide out so they could come along and share it.” (2)
Killer Whale Revenge?
Though the whales have not been actually harming humans, they are sending us a clear message: Don’t mess with them. These are strong animals that weigh up to six tonnes. We must give them both respect and space.