The dangerous Portuguese man o’ war jellyfish has now spread south from the southern stretch of the La Mata beaches across Torrevieja, Orihuela Costa and Pilar de la Horadada, with councils being forced to raise red flags prohibiting any bathing or swimming.

In Orihuela Costa, swimming on La Caleta beach (Cabo Roig) has been banned after two Portuguese caravels were seen this morning (Monday). The councillor of beaches, Luisa Boné, said that the lifeguard service has raised the red flag as a matter of extreme caution.

The Department of Beaches has also published a notice on social networks warning those who plan to go to the beach to be careful and not to touch the jellyfish if they see them, as “their sting can be extremely dangerous.”

In Pilar de la Horadada the red flag has been flying throughout the day on all municipal beaches due to the appearance of the jellyfish. The Department of the Environment has decided to prohibit bathing across the whole of its coastline. They say that once the danger is gone, they will all reopen their beaches.

Guardamar del Segura was the first municipality to alert bathers of the danger. At the end of April, the City Council recorded at least six of the invertebrates and monitoring work was intensified on the Guardamarenco coast.

It was decided to ask the local residents and tourists to avoid swimming on the beaches although they were not closed due to the lack of a lifeguard service.

Local fishermen say that they have sighted several specimens, “but it is very difficult to close 11 kilometres of linear coastline as we have, although we were among the first to initiate warnings and ask people going to the beach to take extreme precautions and avoid bathing”, said the mayor, José Luis Sáez.

The Portuguese caravel has a more potent toxin than the Mediterranean species and its sting is much greater. It could require attention ranging from treatment with antihistamines to hospital admission, depending on the individual.

The tentacles of this invertebrate can be 30 metres long and the most vulnerable to their stings are children, the elderly and people with heart problems. They can even cause death by anaphylactic shock or a severe allergic reaction, so all measures must be taken in order to avoid contact, even when they are stranded on the beach as their bite is still effective.