The first interactions of various killer whale (Orcinus orca) specimens with boats in the Strait of Gibraltar and on the Galician coast were detected in July 2020. Since then they have only increased and prompted the Ministry of Ecological Transition to appeal to mark Is. These cetaceans. At the moment, one specimen is already being tracked and the pilot project intends to install a satellite tracking device for five other conflicting orcas in the strait area. So far this year, the Orca Atlantica organization has detected 53 interactions in the region: 12 have reported damage to ships and 31 have been sightings. A higher figure than in other years at the same time, although it is too early to draw conclusions.
In their interactions, orcas approach different types of boats, “but it is the sailboats that suffer the most because they pry the hull and manage to break it,” says Renaud D., coordinator of the Conservation, Information and Studies Organization Stephanies says. Cetaceans (CIRCE), which collaborates with the Ministry in marking killer whales. The monitoring will allow us to know the location of the samples in the last hours and to prepare a weekly map of the approximate area in which they are moving, Teresa Ribera’s department said in a statement. This information will be shared with the competent administrations, who will disseminate it for the knowledge of seafarers in order to try to reduce the risk of interactions, avoid or reduce navigation through the said areas.
Since first contact three years ago, there have been 744 meetings between North Africa and French Brittany. Of these, 239 were distant sightings of orcas and 505 were interactions in which these animals came close with or without physical contact with sailboats, the data from Orca Atlantica indicate. There are 60 orcas living in the Strait of Gibraltar distributed in several families, some of which are promiscuous and have been selected to establish tagging. A month ago, CIRCE trailed one of them. “The device is set up by shooting a titanium dart from an air rifle, which is attached to the fin, and we expect it to last for about two months,” says De Stefanis. On Wednesday they plan to mark the second copy.
The device provides information in real time and “in this way you can inform where the mammal is”, explains the CIRCE coordinator. Their exact position cannot be determined because they are constantly moving, but the data allows predictive models to predict where they are. The conservation organization has had data on orcas in the strait for 25 years. “We know what they are,” De Stefanis continues. But with their size – they can measure up to seven meters – they are capable of causing serious damage, even to shipwrecks. This May 4, one of the most violent events ever recorded led to the sinking of the Champagne sailboat, in which its four occupants were rescued just in time. Furthermore, “they are learning from each other; They push the rudder with leverage until it breaks. The interactions take place in the spring and summer because at that time they are waiting for tuna in shallow water. “We have realized that the conflict zone is very small and can be avoided,” he says.
Alfredo López, a marine biologist and member of the Atlantic orca group, explains that this year’s interactions have been higher than in previous years at this time, “but we can’t say that they are evaluated until the end of the year, because orcas The area and intensity are changing over time. López avoids using the word assault because it’s a “vague” term, preferring to talk about interactions. The group calculates that 20% of encounters turn serious. and disrupt the navigation of ships. The team has spent years trying to find the key to the initiation of these interactions, and they have even published a scientific publication on the matter in the specialized journal Marine Mammal Science. Considering that an earlier specimen had a traumatic encounter with a boat or a combination of factors, such as a lack of fisheries or disturbance caused by boats, coupled with the curiosity and intelligence of orcas, enabled knowledge to be transmitted social learning.
The marking work, indicates the ministry, provides continuity to the scientific study carried out by the Coordinator for the Study of Marine Mammals (CEMMA) and the Atlantic Orca Working Group (GTOA) on the episode of population interactions in late 2021. Orcas accompanying sailboats in the waters of Galicia and the Strait of Gibraltar. Among its findings, there was an urge to test techniques for minimizing interactions and to deepen knowledge about the species’ habits. The purpose of this pilot project is to show different techniques to give clear guidelines for action, especially for sailboats, that allow their navigation to be safe. Also, the development of actions aimed at preventing orcas from approaching boats will be sought.
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