Rare venomous ‘blue dragons’ wash up on Spain’s beaches, triggering warnings and closures

Rare venomous ‘blue dragons’ wash up on Spain’s beaches (Image: Canva)

Visitors expecting calm seas in Spain last week were surprised. Tiny blue sea dragons, both striking and venomous, washed ashore and forced beach closures. Authorities raised red flags to protect swimmers.

Venomous blue dragon warning
Known as Glaucus atlanticus, the creatures are rare in the Mediterranean. Their silver-grey bellies hide them from above, while streaks of blue shine below. Though beautiful, officials warned they are dangerous to touch. The three-centimetre sea slugs absorb venom from their prey, including Portuguese Man-O’-war jellyfish. Contact can cause burns, nausea, vomiting, pain, or even severe allergic reactions in humans.

Spain beaches on alert
The first sightings were reported in Guardamar del Segura. Mayor José Luis Sáez confirmed their numbers were increasing daily. He ordered closures on 24 August after more of the creatures were found on beaches. Police warned locals not to touch them, even if washed onto sand.

Why are they here?
The animals normally thrive in tropical waters, raising questions about their sudden arrival in Spain. Scientists suspect warmer seas linked to climate change may be driving them north. For now, the unusual visitors remain a danger, keeping swimmers away until the fleet drifts on.