On-board Diary: Emile Baudot, day one. Fields of rhodoliths and concentrations of Gryphus vitreus.

Author: Silvia García
Date: August 8, 2010



Third and last day in the seamounts of the Channel of Majorca that we will explore during this campaign. On this seamount, because of the distance that separates it from the coast -more than 40 nm, both from the Pitiusas and Majorca- fishing has been reduced in recent years to barely some recreational fisherman in search of big trophies. This raises the possibilities of finding ecosystems that are still well-preserved.

 

We have performed three ROV submersions, two of them starting from depths of over 600 m and another near the peak, about 150 m, to document the rhodolith and coralline expanses that exist at its peak. Due to the clarity of the Balearic Islands’ waters, sunlight penetrates the water. This enables coralline to exist down to 150 m. The normal scenario is for it to disappear at 80-90 m, or in very clear waters, down to 100-110 m. This makes its existence at these depths into an exceptional occurrence. This is a spectacular rhodolith field where the variety of sponges we found is huge. These invertebrates know how to perfectly make use of the scarcity of food. They have perfectly developed here.

 

In the deeper areas, we have found a marked presence of brachiopods of the species Gryphus vitreus. This form is considered to be a sensitive habitat by European fishery experts. Therefore, protecting them is of great interest to fishery management because their presence and good condition is important for numerous species of commercial interest.