Seco de Palos is an undersea mountain range 30 sea miles off the Murcia coast, at a depth of between 100 and 3,000 m. Many pelagic species, such as pilot whales, sea turtles, sea birds, swordfish, and sunfish live temporarily or permanently in the area.

Until a few years ago, there was hardly any information on the Seco de Palos species and habitats, except for some studies of its geology and the knowledge of local fishermen. In2007, Oceana was the first organisation to take images of it. To do so, it used an ROV (Remotely Operated Vehicle), and carried out new expeditions in later years.

Thus, Oceana has documented communities of environmental interest, many of which are extremely sensitive to the impact of pollution and some fishing gears, such as trawling and bottom-set longlines, which can be very aggressive against some kinds of habitats and species. Of particular interest are the gorgonian gardens and the fields of soft coral in the areas closest to the top, as well as the crinoid fields in the deeper bathyal areas.

In 2012, samples were taken of an organism which, after being analysed by CSIC, was identified as a new species for science: Spiculosiphon oceana. This is a giant foraminifer that mimics a carnivorous sponge, and the first species discovered by Oceana.

HABITATS AND SPECIES

The images taken by Oceana show a profusion of gorgonian gardens in Seco del Palos. They are found on rocky layers at the top, from 100 m deep, with dominance of the species Paramuricea clavata, a beautiful Medierranean red gorgonia. Viminella flagellum, the whip gorgonian, is found in deeper areas, down to -160 m, and, even though its density is lower, it also constitutes thick gardens. At a greater depth the deep-sea species Callorgorgia verticilata and Swiftia pallida prevail – smaller species that constitute habitats very characteristic of these seabeds.

Soft coral fields are areas with a high number of invertebrates, such asAlcyonium palmatum and Paralcyonium spinulosum. In Seco de Palos they constitute large fields at a depth ranging between 110 and 150 m, in rocky areas.

Finally, rocky areas characterised by the presence of the crinoid Leptometra phallangium in high densities have been found. In certain areas of the Mediterranean this species serves as a crucial habitat for commercial species such as hake (Merluccius merluccius), blue whiting (Micromesistius poutassou) and Norway pout (Trisopterus minutus capelanus). Here it has been found at depths of more than 350 m. In this case, even though the typical habitat for this species is soft seabeds, it has been found mainly on rocky bottoms.

Other interesting species that constitute communities of interest can also be highlighted, such as the tube-building worm Lanice conchilega, very frequent in the soft seabeds in Seco, in a wide range of depths, from the shallowest parts to seabeds that are -600 m deep.