Microalgae ostreopsis in Biarritz: swimming authorized again at Port-Vieux

Swimming is permitted again this Sunday at the Port Vieux in Biarritz. Rates of the microalgae ostreopsis ovata are on the decline again.

It comes and goes. This Sunday, July 20, swimming is once again permitted at Port Vieux in Biarritz. For the past week, the beach has been closing and reopening as samples are collected. The cause is the high concentration of ostreopsis ovata, a toxic microalgae that can cause coughing, sore throat, fever, vomiting, or respiratory problems after exposure.

The results of the measurements estimated by the city are mixed. After peaking at 600,000 cells per liter of water on Tuesday, July 15, the concentration decreased before rising again this Friday. No regulatory concentration threshold exists for ostreopsis ovata. The authorities banned swimming on Thursday, then again on Saturday, with a brief reopening in between.

Tests conducted on Saturday revealed a drop to 33,800 cells per liter. Swimming is now permitted again. More information is available on the Kalilo app and the city's website.