On-board Diary: East of Na Redona. Cabrera

Author: Ricardo Aguilar
Date: June 30, 2007



Spectacular. Today we worked with the divers east of Na Redona to see the transition from here to the more eastern area where we’re working with the ROV. It’s a wall that plunges 25 meters with some areas at just 14 meters, where we see barracudas (Sphyraena sp.), picarels (Spicara spp.) and many other fish. On the sea floor, apart from a few rocks, there is also some Posidonia oceanica.

I say spectacular, however, because of the difference between the two transects we have made with the robot at depths between 60 and 110 meters.

In the first one, the area was devastated by the continuous passing of the trawlers that has destroyed both the coralline and the maërl beds on the sea floor. Although this sea floor is made up of more sandy-mud than the area we visited in the afternoon, you could see many remnants of the concretions of red algae that had been destroyed. The marks left by the trawlers are a constant.

During the second dive with the ROV, we experienced just the contrary; we spotted a coralline platform in very good condition harboring tree sponges, especially large specimens of Axinella polypoides, many rocks full of cavities including lobsters (Palinurus elephas), rugose squat lobsters (Munida rugosa), swallowtail seaperch (Anthias anthias), poor cod (Trisopterus minutus), mullets (Mullus surmuletus), greater forkbeard (Phycis Phycis), cuckoo wrasse (Labrus bimaculatus), etc. If it weren’t for the lack of gorgonians, this spot would have been a paradise. And then the maërl began, mostly comprised of Lithothamnion valens. Atop the maërl, there were many species of ascidians including Pseudodistoma, Aplidium, Clavellina and Diazona, as well as various species of soft red algae such as Fauchea, Phyllopora, Sebdenia, etc.

But what impressed us more than anything else was an enormous kelp forest made up of Laminaria rodriguezii, an endangered species protected by the Barcelona Convention.

It extends various hectares, and some areas are very dense, growing on both coralline and rocks. This is possibly one of the most extensive Laminaria rodriguezii forests in the Mediterranean. I don’t think anyone has ever filmed a forest of this kelp species as dense and spectacular as this one, found between 55 and 80 meters depth.

It looks like the area is in good condition thanks to the large rocks surrounding it that make it difficult to fish in this area.

Once we move away from the rocks, we see the trawling marks again .

It’s one of the most well preserved places we’ve seen in the last few days, but it needs to be protected immediately in order for it to stay that way. This area needs to be preserved by any means...

Now we return to the port of Cabrera to sleep and tomorrow we’ll continue working in this area. In the afternoon, we set sail towards Palma and tie up at port before dark. On Monday, we have crew changes and shopping to do in order to get the boat ready for our next voyage.