On-board Diary: Seco de Palos. Problems with the ROV

Author: Silvia García
Date: July 17, 2010



What was supposed to be three intense days of work in Seco de Palos, a seamount in front of the coasts of Murcia, turned into a quick, two-way trip more than 30nm from the coast.

We reached the area at 7am, having sailed from Almerimar non-stop to be able to start working early and take advantage of the day. We submerged the ROV twice, the first time on a sandy seabed and the second on a rocky seabed with gorgonians and sponges that we already documented during previous expeditions, but we wanted to film it again in HD. But the ROV comes back up from the second dive with a problem. The technicians decide we have to return to port to order and receive a part as soon as possible, because we have no support out here.

We take samples with the dredge of the sandy seabed before we leave and after some level-headed maneuvering, patience and some luck, we are able to disentangle it from an abandoned net, at almost 150m. There's a surprise in store for us.  What we thought was sand is actually fish otoliths (calcareous structures found inside the hearing canal of fish). About 60 to 70% of the seabed is made up of otoliths!! Later on we’ll identify to what species these belong.