[ad_1]
A group of three juvenile killer whales may be responsible for boating incidents that have occurred along the Portuguese and Spanish coasts since the summer, cetacean experts told Lusa.
“We were able to identify three people, all young, who may be in a game attitude. The boats attract the animals, who touch them, provoking reactions and even moving the boat, which is curious to them, ”said marine biologist Rute Esteban.
With a doctorate in killer whales (Orcinus orca) in Gibraltar, the Spanish specialist said that there are “old reports” of animals that “came into contact with ships”, but the difference now is that “it is a repetitive behavior”.
The meetings began in summer and there are about thirty reports on almost the entire Iberian Atlantic coast, from Gibraltar (in the south) to A Coruña (in the north), the last of which was registered in the early morning of November 14 against to Sines. when a boat with three crew members on board had to be towed by the Maritime Police after a group of killer whales damaged the rudder, while sailing 30 nautical miles (about 55 kilometers) from the coast.
Rute Esteban stressed that the rudder “is one of the most fragile elements on ships”, it is easily damaged, and that only with the collection of quality images can it be understood what really happened under water.
The biologist Francisco Martinho makes a comparison of the behavior of young killer whales with “the dogs that chase the cars”, so the recommendation is “stop the engine, lower the sails, which ends the” chase “. by the National Maritime Authority.
According to the biologist, the images “with a certain quality” obtained in the area of Galicia, allowed the identification and naming of the three specimens: two more active, the “Branca” and the “Negra” -which presents “a monumental cut on the head” – and “Gray”, who “seems to be older, acting as a mere accomplice.” Francisco Martinho said it was not possible to assess “the age, nor the origin” of the three animals, believing that they may be part of one of the groups in Gibraltar.
Elio Vicente, head of the Zoomarine Refuge Port, told Lusa that the recorded incidents “are not predatory behavior” and recalled that the “biosonar” of these animals “allows them to know perfectly well that the object is not food.”
For the marine biologist, the hypothesis of being a “negative reaction”, since some of these animals could have been “rammed by boats” when they were on the surface, “is very unlikely”.
The encounters between orcas and boats led to the creation of an informal group of biologists and cetacean scholars from different research groups seeking to exchange information and find an explanation for these incidents.
Sara Magalhães, owner of a whale watching company and one of the group’s members, referred to the existence of “five well-known” families of killer whales that feed on tuna in Gibraltar, the annual spawning gate for tuna. in the Mediterranean Sea. The migration of their main food makes the area a “spectacular place” for the orcas to feed and then follow the schools along the Atlantic coast, the biologist said.
Despite being “well-studied” populations, there is no certainty about the origin of the three individuals that specialists consider responsible for the incidents with boats.
Sara Magalhães said that there were incidents in 2018 and 2019 in the Sagres area with “two hatchlings that became entangled in cables” marking the trap lines (fishing traps) and that they had to be rescued because they were at risk of drowning, which may indicate “behavior of great curiosity.”
Elio Vicente reinforced the need to “continue following” the reports and obtain images that allow us to see “the fluidity of behavior, the approach and the way in which the different animals are organized in interaction with the rudder” or other structures of the boats.
In case of a possible encounter, the expert recommends “caution, avoid negative interactions, warn the authorities, do not enter the water and minimize the motivation of the animals to continue the interactions, adopting the most passive attitude possible”, to reduce In the as much as possible sound and visual stimuli that can arouse the animals’ curiosity, he concluded.
Orcas, mammals of the dolphin family, reach adult sizes of between five and eight meters in length and are social animals with highly cohesive family structures.
