The Portuguese Institute for the Sea and Atmosphere (IPMA) published an alert today about the sighting of Physalia physalis on Portuguese beaches “in unusual numbers” in recent days, in some cases more than 50 on a single beach.

The IPMA said that in recent days it has received sightings from Magoito beach, in the municipality of Sintra, to Terra Estreita beach, in the municipality of Tavira.

Among the species of this type that frequently occur in Portugal, the Portuguese man o' war “is the one that requires the most caution”, as it is “capable of causing serious burns” on the skin, the organisation says.

The Portuguese man o' war is often spotted off the Portuguese coast, influenced by winds and surface currents. It has a “balloon” shaped float that is blue and sometimes shades of lilac and pink, with tentacles that can reach over 30 metres in length. The purpose of these dangling tentacles is to catch fish for food.

The IPMA emphasises that “it is important not to touch” these specimens, “even when they appear to be dead on the beach”, as is often the case with jellyfish, which despite their similar appearance do not belong to the same family.

The IPMA’s GelAvista programme recalls the precautions to be taken in the event of inadvertent contact with a Portuguese Caravel, such as “cleaning the affected area thoroughly with sea water and removing any pieces of tentacles that may have become stuck in the skin with tweezers”.

Those who are affected can apply vinegar and warm compresses and avoid using alcohol and fresh water, warns the IPMA, warning that “in the event of extensive burns, a health professional should be sought”.

Running since 2016, GelAvista (gelavista.ipma.pt) has been inviting citizens to participate in the monitoring of these organisms in Portugal, stressing that any occurrence of this or other species of gelatinous organisms can be reported to the programme.

Information on each sighting (date, location, number of organisms and photograph with object to serve as a scale) should be sent to the email plancton@ipma.pt, or via the GelAvista app available for all mobile devices, says the IPMA.

The Portuguese man o' war is not a jellyfish, but a colony of organisms of the hydrozoan class, with genetically different and highly specialised individuals, but which appear to be a single animal.