A toxic microalgae, called ostreopsis algae, which can cause respiratory disorders and flu-like conditions, has appeared in recent days on the Basque Coast, forcing coastal towns such as Biarritz, Bidart or even Guétary to close their beaches on Sunday and prohibit swimming. “Today, this apparition, we cannot explain it to ourselves”, declared the water quality expert for the NGO Surfrider Foundation Sarah Hatimi, Tuesday August 10 on franceinfo. She talks about a “worrying phenomenon”, because it proves “the effects of climate change on the disruption of biodiversity”.
franceinfo: This alga is usually found in the Mediterranean. How can we explain its presence on the Basque coasts, in the Atlantic Ocean, in the heart of August?
These ostreopsis algae of the genus are rather tropical algae initially, and not Mediterranean algae, and indeed, in recent years, they have found the conditions to settle in the Mediterranean. We have therefore known them a little more in the Mediterranean for some time than on the Atlantic coast. Today, this appearance, we can not really explain it because the climatic conditions are neither met, nor really favorable to the appearance of this algae. It is really a phenomenon that today, it is difficult to understand and difficult to define since, as I said, the algae being tropical, it likes warm water, calm environments, little depth, this which are not really the characteristics of the Basque coast.
“The climatic conditions are not necessarily favorable, but climate change has a lot to do with it.”Sarah hatimi
Usually, do we talk about the effects of global warming to explain the appearance of these algae in the Mediterranean?
Indeed, in the Mediterranean, this is attributed to global warming and climate change. Here too, we will say that it is global parameters that cause biodiversity to go wrong and that there are changes that lead to this appearance today on the Basque coast.
How would you judge this appearance on the Atlantic coast?
Clearly, an appearance in these concentrations and with these effects on health, it is worrying. There have been a lot of testimonials from swimmers, lifeguards, surfers. This is worrying both since we are worried about the effects of climate change on the disruption of biodiversity on the one hand, and on the other hand, it is worrying for the health of users of the sea. , we had a direct effect on the users and their health, with evidence of irritation of the throat, skin reactions and sometimes flu-like symptoms.