A yellow flag has been raised at Las Teresitas Beach in Santa Cruz de Tenerife after several Portuguese Man O' War were discovered on the shore. A special purple flag for marine fauna is also flying, alerting beachgoers to the potential danger. 

A Portugese Man O’ War (Physalia physalis) sting is not merely a mild irritation. It can cause intense pain, muscle spasms and, in extreme cases, neurological and cardiac complications. Although commonly referred to as a jellyfish by the general public, it is actually a siphonophore - a floating colony of polyps that work together and move, driven by wind and ocean currents.

In addition to the flags, the Red Cross is sending out a boat patrol to check for any more of these painful visitors in the swimming areas to ensure the water is safe for residents and tourists.

This is not the first time the Canary Islands have encountered these unwelcome visitors. In the summer of 2023, a six-year-old girl in San Sebastian, La Gomera was stung by a Portuguese Man O' War, leading to temporary beach closures and increased safety measures. They were also recently spotted at La Pinta Beach in Costa Adeje, Tenerife.

They have also recently appeared across much of the southern coast of mainland Spain in recent weeks. Hundreds have washed up on Los Lances beach in Tarifa, on the coast of Cadiz, while specimens of this animal have been located in Malaga, Marbella, Fuengirola, and Benalmádena.

In case of contact, it is advised not to rub the affected area, apply local cold treatment, and wash with saltwater, always avoiding fresh water as it can intensify venom release. The use of creams with antihistamines or corticosteroids is recommended and victims should seek medical attention if the pain is intense or symptoms persist.

Experts have warned that the increase in the number of sightings of these organisms is due to factors such as rising water temperatures, pollution, and the reduction of natural predators like sea turtles. 

“The Portuguese Man o' War is not native to the Mediterranean but to the Atlantic Ocean, where it inhabits tropical waters. However, under certain climatic conditions, it can be carried through the Strait of Gibraltar and reach Mediterranean coasts," explained sources from the Aula del Mar Mediterráneo foundation.

With sea temperatures continuing to rise and pollution and ever-present issue, holidaymakers to the Spanish coast and its islands may have to learn to live alongside these painful organisms.