All united against Ostreopsis, present on the coast of the Basque Country. The “Ostreobila 2024-2026” project was officially launched on Thursday, April 11, 2024. three-year cross-border plan, mixing scientists, teacher-researchers, politicians, coastal managers, laboratories from the northern and southern Basque Country. After three years of preliminary research, their goal is to better understand the functioning of this microalgae and be able to establish health regulations to protect the population.
Identify the toxic variety
“There are currently no health regulations in the Basque Country because we have not set a threshold that allows us to set from what level of cells per liter of water we have a given level of risk of contamination. explains Elvire Antajan, director of the Lerar-Ifremer laboratory. It depends on the species present, its proportion and whether the strain is toxic or not.“The species that is toxic to humans is Ostreopsis ovata, except that molecular observations are not enough to know if it actually occurs in water.” he had to develop tools to analyze the sampleswhich provide results after 24 hours.
Nine places in the Basque Country, including four in the northern Basque Country, are closely monitored: Bidart, Saint-Jean-de-Luz, Biarritz and Hendaye. Bathing water is analyzed once or twice a month. The aim is especially to help town halls, explains Elvire Antajan: “Whether it is necessary to decide on the closure of the beaches or from what limit of Ostreopsis abundance we warn the residents. If only certain more sensitive populations need to be prevented, such as people who have asthma or young children.“Symptoms are quite broad: colds, throat irritation or, in extreme cases, headaches. They appear only a few hours after exposure, especially the “battery” or “metallic” taste in the mouth, which was reported by several affected people.
It is expected on our shores in early June
The authorities officially recorded 900 cases because they consulted a doctor, two of them were hospitalized. To date, scientists are not sure of the route of contamination, but it seems to be mostly aerosol. “The ANSES recommendation is new“according to Laetitia Jourdan, director of the Rivages Pro Tech laboratory in Bidart. National Agency for Food Safety, Environment and Occupational Health”sets a certain threshold in relation to experiences with this alga in the Mediterranean. For example, out of ten reports. Beach closure is recommended in this case.“. Regional Health remains the decision-maker according to the data available to him, therefore the importance of this research for a period of three years.
We also know that toxic microalgae thrive in waters above twenty degrees, so they should return to our shores in late May or early June.