Associació Cetàcea is pleased to present the >technical report in which we analyse the results of the Project Photo-Identification: Whales and dolphins along the Catalan coast. The project, which began in 2014, aims to deepen the knowledge of the cetacean communities that frequent the central Catalan coast, either temporarily or seasonally, as more or less permanently. During the year 2017 we made a total of 25 sighting trips, covering 943 nautical miles and we made a total of 52 sightings in which we could observe up to six species of different cetaceans, the fin whale (Balaenoptera physalus), bottlenose dolphin (Tursiops truncatus), the striped dolphin (Stenella coeruleoalba), the Risso’s dolphin (Grampus griseus), the common dolphin (Delphinus delphis) and the sperm whale (Physeter macrocephalus).

The results obtained confirm, once again that, as has been seen in other Mediterranean areas, the different species observed have a differential distribution within the study area marked by depth. In this way, the striped dolphin, the sperm whale and the gray pilot whale would have a distribution farther from the coast. The sightings of both species usually occur in waters deeper than 400 meters, often located on the continental slope or underwater canyons. On the other hand, the bottlenose dolphin would have a much more coastal distribution, in less deep waters of 200 meters, located on the continental shelf. Finally, the common whale would have an intermediate distribution, with depths varying between 117 and 1233 meters.

The report also presents the first assessment of the photo-identification catalogs of the bottlenose dolphin and the Risso’s dolphin, which currently contain 45 individuals and which have served to verify that some of them have been observed repeatedly and in different years, suggesting a certain residence in the area studied. In addition, the comparison with other catalogs from other regions of the western Mediterranean has shown that, at least one of the bottlenose dolphin individuals cataloged, had been previously observed in areas near the Strait of Gibraltar, and at least another 21 were registered in the coasts of the Gulf of León, in France. This fact suggests the great mobility that individuals of this species can have.

You can access the full content of the report through this link.