On-board Diary: Es Vedra and Sa Bota

Author: Ricardo Aguilar
Date: September 12, 2006



The day starts off a little cloudy, but the sea is fairly calm. We head towards the south-west of Ibiza to document some coralligenous and rocky sea beds in this area. At Es Vedra we want to take a look at the state of the red gorgonians (Paramuricea clavata). On approaching the area, we admire the beauty of the two little islands and their steep cliffs where some Eleanor’s falcons are breeding (Falco eleonorae). We need to dive to below 35 metres to get a good look at the largest gorgonians. Because of the clarity of the water around the Balearic Islands, gorgonians tend to congregate below 35-40 metres as it is a species that prefers the shade.

As far down as 30 metres, the water temperature is still very high (around 25 ºC), while further down the thermocline disappears and the temperature drops rapidly. Our diving session achieves its objective and we find the gorgonians. There is a very high concentration of colonies and they seem to be in a good state.

A little further to the north is the Bajo de Sa Bota. This little seamount has two very distinct sides: one that slopes gently and another which almost plunges down to a depth of 60-70 metres. The combination of rocky zone and sandy bottom gives rise to all kinds of fish. There is also a significant mass of the brown alga Dictyopteris membranacea and, on the walls, a lovely seascape of sponges and small colonial and solitary corals such as Caryophilla sp. and Policyathus muellerae. We’re in luck, and are able to see some examples of the threatened long-spined sea urchin (Centrostephanus longispinus).

Further away, to the west of Formentera, we can see a small tornado forming. In the afternoon it starts raining, developing into a heavy downpour with a lot of lightning. We’ve only had a few drops of rain all day, and now it seems as if the sky is dissolving.