On-board Diary: Seco de los Olivos. Dolphins and gorgonians

Author: Ángeles Sáez
Date: June 22, 2010



LIFE+ INDEMARESFirst substitution of "galley slaves". Eva and Nati disembark and I come on board along with Soraya. And I couldn’t be any luckier. I was assigned the videographer's “suite-cabin" and the seas are calm, the sky is blue and visibility is excellent. The excitement begins 15 minutes after we set sail: a group of roughly one hundred common dolphins (Delphinus delphis) (link) appears and stays with the Oceana Ranger for a few minutes. Not long after, a smaller group of bottlenose dolphins (Tursiops truncatus) makes an appearance. We identify concentrations of a brownish-orange substance on the surface of the sea in some areas of the crossing. Samples are taken and, with the help of a microscope, we realize the substance contains a bloom of Noctiluca scintillans, a very peculiar dinoflagellate, known by nighttime swimmers for the glowing light it gives off upon contact.

We dive with the ROV on a peak west of the main seamount. The high definition camera shows images of seabeds with Asconema setubalense sponges, schools of swallowtail seaperch (Anthias anthias), sea urchins (Cidaris cidaris) and quite a few holothurians (Parastichopus regalis). As well as many abandoned lines and remnants of fishing gear.

After lunch, we dive off the main seamount. Ricardo's predictions were correct and we find rocks covered by gorgonians Paramuricea clavata and Eunicella singularis. Later on we also identify an Elisella parapleaxauroides gorgonian, colonizing ascidians (Diazona violacea), more swallowtail seaperch, rainbow wrasse (Coris julis), corals , the enigmatic basket stars (Astropartus mediterraneus), remnants of mollusc shells, dead corals, a small-spotted catshark, bluemouth rockfish, and a cuttlefish. And the constant appearance of marks left by the trawlers on the seabed. After our work in the sea is finished, it’s time to organise and analyse. Ricardo and Silvia observe the different samples using binocular magnifying glasses. Fleta organises the video footage and images recorded by the ROV. There’s so much to see and I don’t know where to look, so I go back and forth.

Galley slave? My first day is over and I haven’t even touched an oar. I came onboard prepared to sing the Song of the Volga Boatmen