For several decades, researchers at the University of Liège have been measuring different parameters of the waters of the Mediterranean. This long series of measurements carried out in a relatively pollution-free zone of the Mediterranean makes the STARESO research station in Corsica a reference site for all marine studies. This is the case with the phytoplankton studied by Anne Goffart.

Established by Rector Marcel Dubuisson, a renowned oceanologist, the underwater and oceanographic research station (STARESO) of the University of Liège is situated in the bay of Calvi, on the western side of Corsica. The site was chosen for the exceptional quality of its water and the surrounding environment. The site has kept its importance because of the variety of its ecosystems and also because the quality of the water is still very valuable to researchers today. Thanks to the policy of conservation led by the Corsican regional authorities, the waters around the STARESO site have always been protected and pollution of an anthropic nature is minimal. This fact, coupled with the continued conservation measures enacted over a period of more than thirty years makes STARESO a unique site: the development of the sea environment can be studied in a pollution-free zone, which allows researchers to monitor the changes brought about by global warming. The same goes for the study of phytoplankton, studied by Anne Goffart, research fellow at the oceanology laboratory of the University of Liège and scientific director of the university’s STARESO site.

The root of all sea life

The phytoplankton is made up of tiny microscopic algae almost always less than one millimetre and more exactly from one-tenth to one-hundredth of a millimetre. Its size is inversely proportional to its importance, as the phytoplankton constitutes the basis of the marine food-chain. It there weren’t any phytoplankton there wouldn’t be any zooplankton as the latter feeds on the former and consequently there would be no sea animals. The presence of phytoplankton in the oceans is thus vital. But it is not only important for its presence alone: its composition and the size of its component cells also play an essential role. «All things being relative, the components of phytoplankton are as different from each other as a cherry is from an apple or a melon. The animal that eats the cherry must have a different-sized mouth to the one that eats the melon. This size differential forms the basis for the food-chain. If there are only large cells which can only be eaten by animals that are relatively «big», for example, this poses a problem for smaller animals. The same would apply where there are only small cells. Whilst larger animals could certainly eat them, they would need more energy in order to do this: this situation would therefore not be ideal. Thus we can see that there is a direct relation between size of the components of phytoplankton and the way marine life has evolved and is organised», explains Anne Goffart.