Off the east coast of Formentera there are areas where we can find a combination of walls full of sponges, rocky zones and sandy areas with Posidonia oceanica. Here we can see bigscale scorpionfish (Scorpaena scrofa), cardinal fish (Apogon imberbis), peacock wrasse (Symphodus tinca) and red mullet (Mullus barbatus). There is also a wide range of sponges, with species from the genera of Tenacior, Crambe, Sarcotragus, Cacospongia, Chondrosia, Oscarella, etc. There are also anthozoa such as Parazoanthus axinellae and bryozoa such as Miriapora truncata.
In the afternoon we decide to visit a couple of small seamounts to map their bathymetry, as we will be coming to work here later with the robot submarine. The summit of one of them, Auxias Marc, comes up to 80 metres below the surface before dropping to depths of more than 400 metros. The other, Las Olivas, is even deeper.
No sooner have we arrived at the second seamount than a group of eight bottlenose dolphins (Tursiops truncatus) appear to welcome us. Seamounts tend to congregate a huge range of fauna and, as we saw on the Seco de los Olivos seamount in Almeria, bottlenose dolphins are very frequent visitors.
Night falls, and we start sailing among thousands of purple jellyfish (Pelagia noctiluca). There are incredibly high numbers of them, and as the light disappears their bioluminescence becomes more and more evident.