On-board Diary: Excitement

Author: Ricardo Aguilar
Date: August 2, 2007



Today has been an exciting day.

We had a good scare. The little seamount we went to sample turned out to be the most complicated one of all. The lines, nets, ropes and other fishing tackle abandoned here have transformed this seamount into a spider web. And to top it all off, the robot got tangled in a longline at 170 meters depth.

After a lot of hard work, and a good measure of luck, we were able to haul the equipment onboard. It was, however, covered in lines, buoys and hooks. Now we have to verify that nothing has been damaged.

But these abandoned remnants have not only affected the ROV, they have damaged the entire seamount. The rocks are almost barren and many gorgonians and sponges are broken.

As we haul the ROV onboard, we look around us and see the amount of recreational boats fishing in the area. Many of them use grapnels to anchor and, if they cannot recuperate them, simply abandon them in the area. I wouldn’t be surprised to see a few pirates camouflaged as recreational fishermen, setting longlines with hundreds of hooks or other "semi-professional" fishing tackle like the one that snared us. It wouldn't be a bad idea for the fishing patrol boats to come around this area on a regular basis and supervise all this illegal activity.

The positive part of the day was some of the species we've found here. Some large specimens of grey grouper (Epinephelus caninus), rugose squat lobsters (Munida rugosa), solitary corals (Caryophyllia spp.), yellow tree corals (Dendrophyllia cornigera) -many of them quite thin and with few polyps), brachipods and crinoids hidden amongst the rocks, various sponges and gorgonians and, best of all: carnivorous sponges (Asbestopluma hypogea). These animals are very rare and are usually found in caves or at great depths. Unlike other sponges, instead of filtering water to trap plankton, the carnivorous sponges feed like a carnivorous plant. They have long filaments in which small crustaceans and other organisms get caught.

This species was discovered in the Mediterranean in 1994, in a cave off the coast of Provence and then again in two other caves in Marseille and Croatia. All the specimens found to date have been located in submarine caves at 15-20 meters depth. Now we have proof that they also occur amongst rocks at almost 200 meters depth. And as far as we are aware, this is the first time this species is found in Spanish waters.

In the afternoon, and while tests were being run with the ROV, we continued our work with the divers on the Mesophyllum reefs. Many species can be found hiding in the large quantity of cavities found here. Now we must check that the photographs and film meet our expectations and identify the species.