(BV / 04-05-10)  The main fear of bathers is back. Although it feeds on crustaceans and fish larvae, likes also to human skin. It prefers the cold waters of the Atlantic but, judging by recent sightings, it seems it is happy in the Mediterranean. We are talking about the the Portuguese Man o' War (Physalia physalis), a kind of colony of jellyfish (animals related to jellyfish) whose presence last year in the costs caused great alarm, and which has seen again in the waters of Murcia and Valencia coasts.

Although these are specific sightings, as Oceana stresses, some experts say it will shift to the Balearics. To prevent the alarm occurred last year, the Spanish Ministry of Environment has already organised special operations to monitor and record all sightings of the Portuguese Man o' War occurring anywhere in the country. To this, technicians, Civil Guard and fishermen will work together and will notify it in case they see a specimen.

Silvia García, marine scientist from Oceana, ensures that at the moment "they are single sightings, but after the social alarm last year, it has been launched a surveillance campaign that implies that anyone who sees the Portuguese Man o' War has to notify the 112.” Although it had not appeared for a decade in the Mediterranean, this is the second consecutive year that it is detected on the Spanish coasts.

However, García ensures that “now its presence is more controlled, before it went unnoticed and so it was not documented, although now the number of specimens in Spanish waters is unknown.”

In this sense, Silvia García considers that the presence of these animals related to jellyfish is unpredictable. Air currents move them to the Mediterranean and also other factors favour its arrival, such as climate change, overfishing or the abundance of food.

“Very important” mass coming from the Atlantic

The ICM/CSIC post-doctoral researcher Dacha Atienza considers that from February there is a “very important” mass of these animals coming from the Atlantic Ocean stranding in the Andalusian coasts. They are moved by currents and it is foreseen that, according to this movement, they will be going to the Balearic Archipelago.

According to data, the phenomenon is similar to the one occurred last year, when these specimens were found in Malaga and then in Formentera, according to the natural circulation of sea water which enters through the Strait of Gibraltar and moves through eastern Andalusia and Murcia to the Balearic Islands.

Portuguese Men o' War are easy to identify because they have a very big blue float and move over water surface thanks to a gas-filled bladder that looks like a ship and which is named after. Its bluish balloon shape hides stinging tentacles 30 meters long.