On-board Diary: In Columbretes

Author: Ricardo Aguilar
Date: July 4, 2007



Finally, we left Palma de Mallorca at 1:00 in the morning and set sail towards El Placer de la Barra Alta. It was good sailing and at some point, with the jib hoisted, we reached 10 knots.

At some 25 miles east of Columbretes we see a flock of shearwaters feeding on a bank of small pelagic fish that look like sardines or round sardinella. Later on we see another bank were small tuna are feeding. Finally, the striped dolphins appear (Stenella coeruleaolba), playing with the ship’s bow for a while.

At around 13:00, we were in the area surrounding la Barra. We began working with the ROV immediately, sampling areas up to 95 meters depth.

Below 70 meters, everything is quite torn up. In the southern area, first we find a sandy mud floor then quickly come upon an area that used to be maerl bed, but is now completely destroyed.

At approximately 50 meters, the floors are extensively covered in Peyssonnelia. Immediately after, there is a rocky area that extends up to the surface of the mound, where we find brown and red algae, especially Dictyopteris membranacea. Also, the maerl here is in good condition and is mainly made up of Phymatolithon calcareum.

The slopes are in better condition on the mound, except after 70 meters depth where the marks left by the trawlers are abundant. There are maërl beds, Peyssonelia, rocks and many sponges, although most of them are small, except for some Axinella polypoides that are quite large. There is also considerable diversity in this area. In the deeper area, we find an isolated gorgonian (it also looks like Paramuricea macrospina), and another area harbors fish nests that cover an extensive area. Further ahead, there is sandstone and then mud full of holes similar to the ones made by Norwegian lobsters.

Before it gets dark, we head towards Columbretes where we will spend the night because the day was quite complicated due to the weather that has made it difficult to work. Tomorrow, we will verify the state of the area we visited last year and, if we have time, we’ll take samples of some hollows there.