Between March 17 and 31 the INCOGEO0310 oceanographic campaign was conducted by the Spanish Institute of Oceanography (Instituto Español de Oceanografía). The campaign’s aim was the multibeam bathymetric survey and high-resolution seismic scouting of the scarcely studied Conception Bank. This area qualified as a candidate for marine IBA (Important Bird Area) in the recently published inventory Areas Important for the Conservation of Marine Birds in Spain, which was the fruit of a LIFE project carried out by SEO/BirdLife and co-financed by the MARM. The difficulty involved in accessing the Bank and surveying the water in detail prevented data of adequate quality from being collected in order to confirm the area as a marine IBA.

Because of this, an observer from SEO/BirdLife participated in the present campaign with the aim of obtaining detailed information about marine birds that use this enclave in the spring. Given the characteristics of the boat (Vizconde de Eza) and the work plan, which involved sailing at speed and with a constant route for the purposes of the bathymetric survey, the campaign was ideal for carrying out transect censuses of marine birds. So censuses were conducted both in the study area and in the outward trip from the port of Santa Cruz de Tenerife to Lanzarote. In addition, as a complementary activity, all observations of turtles and cetaceans were recorded.

The sea conditions were generally good, although there were several moments when the swell and the wind made it inadvisable to enter the work area, which was situated on the external deck of the boat’s bridge. In total, a census was taken throughout 547 nautical miles, covering a surface of some 602 km2 with an effective census time of 58.3 hours.

Among the species of marine birds observed, the Cory’s shearwater clearly stood out in terms of numbers, representing almost 90% of the total specimens recorded. This fact highlights how important the area is for this species. Other species notable for their abundance were the sandwich tern and the white-faced storm-petrel, although we should bear in mind that most observations of the latter were made on the outward trip to the Bank. Indeed, the low number of white-faced storm-petrels detected strictly in waters of the Bank is worthy of note, as is the case with other target species (the little shearwater and the Madeiran storm-petrel). Other species, such as Bulwer’s petrel (of which only one specimen was observed, near Tenerife) and the European storm-petrel, could feed themselves in these waters during the summer months, which coincide with their reproductive period in the Canary Islands.

According to the censuses conducted, the cetaceans are represented in the Bank by at least six species. Among these, three species of dolphins are notable for their abundance (the spotted, common bottlenose and common dolphins) and to a lesser extent also the short-finned pilot whales, which use the neighbouring areas of the Bank. The sperm whale and three specimens of rorqual (Balaenoptera sp.), which could not be precisely identified, complete the list of cetaceans. To this we must add various specimens of Risso’s dolphin observed to the north-east of Tenerife outside the area of study and another fourteen specimens of loggerhead sea turtle in the waters targeted by the study.

At first glance we can see the importance of the area for the Cory’s shearwater, and several species of cetaceans and turtles are also evident. In the case of the cetaceans, the presence of a good number of bottlenose dolphins is worth noting, as it is one of only two species of Spanish cetaceans included in Appendix II of the Habitats Directive. All of these results support the inclusion of the area as a candidate for the marine IBA and the Natura 200 Network (ZEPA and LIC), making it important to continue the surveys in order to finish profiling the area’s significance and complete the information regarding birds, cetaceans and turtles that use the area at other times of the year.