Overview

• Guardamar del Segura reinstated red flags on August 23 after rising numbers of Glaucus atlanticus, and bathing remained prohibited along affected Costa Blanca beaches on Monday.
• La Cantería beach in Órzola, Lanzarote, was temporarily closed this week following additional sightings of the species.
• The sea slug can deliver a painful sting that may cause nausea and, for people with severe allergies, dangerous reactions.
• Officials urge beachgoers to alert lifeguards or police if they spot the animals, avoid touching them, and follow local first-aid guidance such as rinsing with salt water before seeking care.
• The species is rarely seen in the Mediterranean, and experts have suggested warmer seas may be contributing to recent sightings in Spain.