Since 1991 it was begun to detect the expansion of an invading algae variety, Caulerpa racemosa, that origin of Australia entered in Mediterranean Sea through the Suez Chanel. It extended to the north and west: Greece, Croatia, Italy, France and Spain. It arrived to the Balearic Islands at ends of ’90 and began to colonize Mallorca and Ibiza. Even thought there were other varieties of these same algae introduced in the occidental Mediterranean Sea since ’30, this new variety is especially aggressive.

In waters of western Mediterranean Sea these variety of invading species can be favored by changes in the climatic models than preview the effects of changes climatic. And it could be perjudicial to certain species and natives habitats.

1. Caulerpa racemosa creats extensives prairies in areas occupied by natives species from Mediterranean Sea, like (Posidonia oceanica)’s meadows or algueró (Cymodocea nodosa). Also it’s able to colonize rocky substratum. Its great competitiveness to Posidonia and Cymodocea is due to its quick growth and that it can reproduce from small pieces, than can be transported easily by bouts. Besides there are very few enemie to these algae. Now it seems to be a few species of animales that eat these species of algae. The Caulerpa racemosa invasion has solely been able to stop in those cases in which it has been detected precociously.

2. One consequence of the climatic change will be the heating of seawater, and not only in surface, but also in depth, fact that could affect to the state of the marine prairies. We can’t forget that one of the habitats that are threatened by the invasion of Caulerpa is the prairies of posidonia, an important CO2 drain in the western Mediterranean. On the other hand, some studies indicate that in depths from 30 ms, C. racemosa can form a continuous and very dense carpet. It is therefore, it is to anticipate that its expansion could be greater of predicted thing. The work with ROV (Remote Operated Vehicle) within the campaign “the Caixa” in favor of the sea, the route of Vell Marí, tries to contribute to give new data on this invading species.  To know the limits of distribution of this invading species, not only in surface but also in depth, is fundamental to be able to anticipate and control its advance.

Date accomplishment: from 1 to 14 September
Location: Waters of Eivissa and Formentera

Watch the final report in PDF format:

Informe sobre la exploración (IN SPANISH) [Size 2,6 Mb] Note: This report contains 2 campaigns more form 2008.