Sea canyons attract sperm whales
UNDERWATER canyons close to the French border – where the foothills of the Pyrenees meet the sea – are ‘of special importance for cetaceans’, according to Barcelona-based association Submon.
Situated off the rugged Cap de Creus and Palamós in Cataluña, they provide a habitat for ‘deep divers’ such as the sperm whale.
Submon noted that they have just finished their AHAB project, researching the northern area of the Mediterranean Cetacean Migration Corridor.
They set out to confirm that the underwater canyons are potential habitats for deep-diving cetaceans and that it is a feeding area for the sperm whale.
In the study area, the most sighted cetacean species was the striped dolphin followed by the Cuvier’s beaked whale, the sperm whale, the long-finned pilot whale and the Risso’s dolphin.
“On the other hand, the most acoustically detected have been the striped dolphin and the sperm whale with the same number of detections, followed by the Cuvier’s beaked whale, pilot whale and pilot whale,” they added.
Thanks to the acoustically obtained data, the first estimate of sperm whale abundance has been made in the area of the Cap de Creus and Palamós canyons, which is around 21 animals.
In addition, both groups of females with juveniles and young have been observed, as well as a solitary male.
A total of 12 sperm whales have been photo-identified, which have been compared with individuals identified in other areas of the Mediterranean, such as the Balearic Islands, the Strait of Gibraltar and the Gulf of León.
As a result it has been detected that some of the sperm whales observed by Submon both during this project and in a previous project, move through the area of the Gulf of León.
One of the individuals observed during the AHAB project was spotted a few days later in the north of the Gulf of León and an individual observed by Submon in the same area in 2010 was seen eight years later in the northern area of the Gulf canyons.
Both individuals are possibly male and the re-sighting eight years later supports the importance of the area for the movements of males in this part of the Mediterranean.
The Tursiops association has identified another possible re-sighting of another of the sperm whales sighted during the AHAB campaign – a male individual observed and identified in the waters of the Balearic Islands in several previous years.
“Thus, the underwater canyons of Cap de Creus and Palamós prove to be an area of special importance due to the presence of deep-diving cetaceans, and especially the sperm whale, given their high density,” they concluded.
“The presence of both males and groups of females would indicate this area as a feeding and breeding ground, giving a special value to these canyons.
“The continuation of this study is considered very important in order to increase the robustness of the results and thus be able to apply management measures in the area for the protection of these animals.”
They were able to confirm the connectivity of this species with other areas of importance for sperm whales, such as the Balearic Islands, Liguria or the south of the peninsula and, therefore, the use of the Cetacean Migration Corridor.
Submon work to preserve marine biodiversity and to reach a sustainable use of the marine environment ‘through promoting a change in the relationship between society and the ocean, conducting actions in situ and sharing knowledge’.