A deadly virus outbreak detected on the coast of Barcelona

On 7 September, a grouper found in waters near Barcelona revealed the presence of betanodavirus, also known as viral nervous necrosis. The specimen, handed in by a member of the Associació de Pesca Submarina, was analysed at the UAB, where a massive infection in its nervous system was confirmed.

This virus, which for years has caused severe mortality among groupers and other species throughout the Mediterranean, has spread from Baleares, Italia y Grecia to the Catalan coast, raising alarms in sensitive marine reserves such as Cap de Creus and the Illes Medes.

In response to the risk of new outbreaks, the UAB and the Instituto de Ciencias del Mar (ICM-CSIC) have launched an early warning network that combines science and citizen collaboration. Divers, recreational fishers and natural park technicians are taking part in the monitoring, becoming the first sentinels of a silent threat.

Experts stress that advanced diagnostic tools and experimental vaccines could help contain the impact. The case also shows how society’s involvement is key to protecting marine biodiversity against a fast-moving invisible enemy.