The killer whale (Orcinus orca) is a large aquatic mammal that can measure nine meters long and weigh between 3,500 and 6,000 kg. Its coloration is black with large white spots on the face and belly. Males and females are distinguished, above all, because they have larger fins. It is also characterized by forming very stable herds and being very long-lived, living between 50 and 60 years.

The greatest threat that this species has in the world is poisoning by PCB pollutants, which despite being banned in Europe 30 years ago is still present in the environment, according to recent research. Likewise, the majestic mammal suffers a serious degradation of its habitat due to intense marine traffic and overfishing of its base food.

The populations of this mammal have different behaviors from each other depending on the region they inhabit. This is according to a recent study carried out by the CIRCE (Conservation, Information and Study on Cetaceans), which has concluded that the orcas of the Strait of Gibraltar have different habits and characteristics from those of the rest of Europe, that is, they are unique, so they need specific conservation measures. The project of this entity is generating a national catalog of orcas to improve the last inventory of this species, in which 60 specimens were identified. At the same time, it implements conservation and protection measures for these cetaceans in our country, where it is classified as vulnerable by the National Catalog of Threatened Species.

The project, which has the support of the Biodiversity Foundation of the Ministry of Agriculture, Food and the Environment, is part of the “Conservation Plan for killer whales in the Strait and Gulf of Cadiz”, which is currently pending publication.

In the case of the population of the Strait of Gibraltar, killer whales feed mainly on bluefin tuna (Thunnus thynnus), which means a great interaction with fishermen in the summer months of the year and which is currently being studied through satellite tagging of six specimens. In other regions, their diet may be based on seals, sea lions, birds, sea turtles, octopuses or cuttlefish that they hunt with very sophisticated attack strategies in which several specimens cooperate and communicate through waves to set the ambush.

In Spain, in addition to the Trafalgar area during the months of March to June, and in the western area of the Strait from June to August, specimens have been sighted in the cold waters of the Atlantic coast, especially in Cantabria and Galicia; although the killer whale is indifferent to living in warm or cold waters and only chooses its habitat for the abundance of food it can find in it.