We left early to reach the canyons before the wind picked up so we could work comfortably, without the boat moving too much. We reached the Potera Arrechu seamount and surveyed the area but did not find any significant changes in depth. A group of 15 common dolphins (Delphinus delphis) appeared directly over the seamount and played with the bow.
Taking advantage that we were close to the canyon facing Ondarroa, we went there to survey the area and study its morphology, in order to identify possible areas were we could work with the ROV once we installed it and submerged it to 300 meters depth. Like the rest of the canyons where we’ve worked in the Cantabrian, we were impressed by the sharp vertical drops and slopes that, in this case, dropped from 137 meters to 500 meters depth.
In the afternoon, we returned to the coastal area to dive off a seamount E of the Ea Point, in a rocky area comprised of slabs. The seabed, covered by Cystoseira algae, harboured rich biodiversity. Similar to other days, we documented an abundance of certain species, including conger eels (Conger conger), ocean sunfish (Mola mola), moray eels (Muraena helena), rainbow wrasse (Coris julis), cuckoo wrasse (Labrus bimaculatus), seabass (Serranus cabrilla), Ballan wrasse (Labrus mergylta), bogues (Boops boops), pouts (Trisopterus luscus) and a few specimens of red blenny (Parablennius gattorugine), corkwing wrasse (Symphodus melops) and yellow-headed goby (Gobius xanthocephalus).
Amongst the crustaceans, we found Galatea strigosa, in bright red and blue, and a slipper lobster (Scyllarus arctus), as well as an abundance of mysids swimming in the water column close to the seabed.