A massive outbreak of venomous purple jellyfish is swarming popular tourist areas in central and northern Greece, forcing authorities to issue urgent warnings to swimmers as the country’s peak holiday season gets underway.
Swarms of the jellyfish, known scientifically as Pelagia noctiluca, have been concentrated in the Pagasetic Gulf and have spread across the Sporades islands, including the major destinations of Skiathos, Skopelos, and Alonissos.
The bloom has alarmed scientists and tourism operators, who fear it could disrupt the summer season.
Though visually striking, the purple jellyfish carries a powerful and painful sting that can cause burning, skin irritation, and, in rare cases, more severe allergic reactions.
Officials are advising beachgoers to avoid contact with the jellyfish and are urging the public to help monitor the outbreak by reporting sightings to online biodiversity trackers.
Scientists say this year’s surge is part of a wider pattern across the Mediterranean.
They attribute the increasing frequency and intensity of these blooms to rising sea temperatures and the overfishing of natural predators like tuna and sea turtles, which allows the jellyfish populations to expand unchecked.
The Hellenic Biodiversity Monitoring Network has noted particularly high concentrations moving from the Pagasetic Gulf toward the open Aegean Sea, affecting the coast of northern Evia.
Health authorities advise that anyone stung by the jellyfish should immediately rinse the affected area with seawater, not fresh water, and carefully remove any remaining tentacles with a flat object like a credit card, not with bare hands.
Applying a paste of baking soda and seawater can help soothe the irritation.
The situation presents a new challenge for coastal communities already navigating the pressures of record tourism and a changing climate.