On-board Diary: Seco de los Olivos (day 1 and 2)

Author: Ricardo Aguilar
Date: July 28, 2007



Once in Almeria, we’ve made the port of Almerimar our base for operations in order to work in Seco de los Olivos between Punta Entinas and Punta Elena.

On the first day, we head out to Seco to see one of the small elevations there are towards the east and to look around the top of the main seamount in the afternoon.

The summit of the small elevation east of Seco is at approximately 90 meters. From there, an area of rockfalls extends to 130 meters and then we reach the sandy sea floors.

We analyse the two slopes and while whip gorgonians occur frequently on one side (Viminella flagellum), on the other side the deep-sea gorgonians Callogorgia verticillata are more frequent. But what is most abundant in the area are remnants of abandoned fishing tackle that make the place look like a cemetery of nets, lines, ropes, etc., and a very difficult place in which to move the undersea robot without getting tangled.

This place harbours some grey groupers (Epinephelus caninus) that are in the habit following the robot. A few of these have battle scars from numerous battles they've fought. Sometimes it's a cloud of swallowtail seaperch (Anthias anthias) and mackerel (Trachurus trachurus), along with some scale-rayed wrasse (Acantolabrus palloni), that swim around the robot.

During the afternoon dive on the main seamount, the surface between 80 and 129 meters depth is mainly uniform. The slope is not pronounced and has sandy areas with small and medium-sized rocks where a multitude of gorgonians can be found (Eunicella verrucosa, Paramuricea clavata, Bebryce mollis, Viminella flagellum, Elisella paraplexauroides, and we believe we have identified some Villogorgia brebycoides) and yellow tree corals (Dendrophyllia cornigera). The solitary coral Caryophyllia cyathus appears on some rocks.

The next day, we concentrate on the area in front of the immense sea of plastics in Almeria, between Roquetas de Mar and El Ejido. The developments are surrounding this natural spot little by little, but there is still a stretch that is undeveloped. Here, on the sea floors, there is an area of high ecological value that harbours mixed meadows of Posidonia oceanica and Cymodocea nodosa, maerl beds and Mesophyllum alternans reefs. Some of these areas are plagued by violet sea urchins (Sphaerechinus granularis).

After the first transect with the ROV to limit the area and see the state of conservation, the divers are going to inspect the sea floor where we’ve found the densest population of red algae reefs.

A common eagle ray (Myliobatis aquila) takes off when it sees us approaching. Underneath us, rainbow wrasse (Coris julis), damselfish (Chromis chromis) and different types of blennies are the first to appear before our eyes. Then we spot some nudibranchs, molluscs, polychaetes, anemones and a couple of spider crabs (Maja crispata).

In the western area, the meadow is comprised only of Posidonia oceanica and seems to have suffered a severe recession. First, we find some dispersed shafts and it is not until we reach 16 meters depth that the coverage is more considerable, although the meadow is very fragmented even there. And to think that years ago, the seagrass meadows reached down to almost 40 meters depth from the surface of the water.

Tomorrow, we will return to the Seco de los Olivos to sample the other small elevations.