ANSES warns of the proliferation of Ostreopsis on French beaches. This microalgae has already caused several hundred poisonings…
Ostreopsis. Remember the name of this microalgae and above all learn to recognize it in order to distance yourself from it. In a communicated of June 20, the National Agency for Health and Food Security (Anses) issued an alert on its proliferation on the french beaches and recommends a set of measures to protect against it. According to the authority, Ostreopsis would have caused nearly 900 poisonings since 2021. It is by inhaling sea spray that one can be intoxicated and “just be a few meters from the sea” only.
What is Ostreopsis?
Ostreopsis is a microscopic algae of tropical origin who arrived in Mediterranean twenty years ago. In France, the distribution area of this microalga extends, with a presence on the Basque coast for a few years. It proliferates especially in summerwhen the water reaches a temperature of more than 20°C. She can then accumulate on the surface of the water For form “water flowers”. These blooms can create brown tablecloths which can reach several square meters.
What symptoms should alert?
The inhalation of microalgae by sea spray leaves “the feeling of a metallic taste in the mouth, even if it was only inhaled and not ingested” details ANSES. Ostreopsis produces toxins which, in the event of poisoning, lead to flu-like symptoms, skin irritations and stomach upset. The signs appear a few hours after contact with the microalgae or its toxins and disappear within a few days. Prolonged exposure can lead to a lengthening of symptom duration. “THE people with breathing problems are most at risk of developing symptomssays Carole Catastini of ANSES. They should avoid being near the coast when there is a proliferation of Ostreopsis.” THE professionals working on or near the beach. (lifeguards, restaurateurs, for example) are also more at risk of poisoning.
What to do ?
If Ostreopsis bloom is confirmed, a prohibition of nautical activities and the closure of beaches can be decided. People with symptoms of poisoning should report them to their doctor. For professionals at risk of exposure “an arrangement of working time could be considered in order to limit their duration of presence”. ANSES also recommends wearing protective equipment for people in charge of water sampling, in particular masks and gloves. Finally, the authority considers that it would be necessary adapt the frequency of water withdrawals depending on the concentration of the microalgae. THE health checks of bathing water are usually carried out every 15 days. This frequency could become weekly or even daily when Ostreopsis is detected “in order to closely monitor the situation which can evolve in a few days”.