On-board Diary: The last day of the campaign
Author: Ricardo Aguilar
Date: September 30, 2007
We begin the last day with calm seas and practically no wind. We are east of Columbretes at seven in the morning, profiling the canyon that is located there with the sonar. The surface is at approximately 120 meters depth, falling to 600-700 meters from there, and the walls are almost vertical in some parts.
We choose an area where there is a little of everything: sharply sloping walls and some with softer slopes. We submerge the ROV and watch the lights disappear as we descend to 100, 200, 300 and 304 meters; a record for us. A steep wall appears in front of us, completely covered by sediments, forming strange, crest-like shapes. As if they were hanging, we spot some megrims (Lepidorhombus boscii) upside down, as well as various species of pandalid shrimp.
There are also some small valleys that habour lobsters (Palinurus elephas), greater forkbeards (Phycis blenoides), gadellas (Gadella maraldi), blue ling (Molva dypterigia) and bluemouth rockfish (Helicolenus dactylopterus), etc.
The large amounts of sedimentation make it almost impossible to find species fixed to the substrate. We find neither corals nor gorgonians and only a few sponges.
In the afternoon, we carry out two dives, or better said, three dives, because the second one had to be suspended when we found a net, and the third dive, although it was a bit longer, also had to be suspended for the same reason. We better not take any risks on the last day.
The sea bed is comprised of mud in the northern part of Columbretes, with a large quantity of suspended sediment and barely any visibility. In spite of this, the rocks we find scattered here are full of life including yellow gorgonians (Eunicella cavolini), various species of sponges, bryozoans, hydrozoans and a wide variety of fauna. Flora is not abundant due to the depth, approximately 90 meters, and the lack of sunlight.
We carried out the next dives in the west, around the banks at 50-60 meters depth. Here, the queen is the red gorgonian (Paramuricea clavata) and we see some spectacular specimens, as well as wing shells (Pteria hirundo) and other species living on top of them. There are some yellow and pink gorgonians (Eunicella verrucosa), although they are less common. Amongst the hydrozoans, the large sea beards (Nemertesia sp.) dominate the sandy sea bed along with the maerl.
We decided to finish our work as soon as the nets surrounded us and night fell, setting sail towards Sagunto. Now we must prepare our work for the upcoming months.
The campaign for this year has ended and, once again, the Ranger has behaved wonderfully.