Since early July 2025, beaches of the Basque, Cantabria, Asturias and Galicia have recorded a significant increase in the presence of the Portuguese caravel, forcing authorities to lift red flags in bathing areas such as La Concha and Ondarreta in Guipusan. The phenomenon, which directly affects swimmers and tourists during the high season, is being investigated by experts that point to multiple causes for the emergence of this species, besides global warming.
Physalia Physalis, known as the Portuguese caravel, is an ordinary open sea colonial organism, especially in temperate Atlantic waters. However, according to the Spanish newspaper 20minutos, its presence on the northern beaches of Spain has been increasing in recent years, reaching particularly high levels this summer. According to Lourdes González, biologist and sub -director of the Cantabric Maritime Museum, this species already appeared occasionally on the songs, but the current frequency and number raise additional concerns.
Chains, winds and warmer waters drive the advance
Among the most cited factors to explain this occurrence is the change in the direction of the winds. As Diego de Vallejo explained, environmental disseminator quoted by the same means, the atmospheric currents are blowing more intensely towards the song, which favors the transport of these floating organisms to the coastline.
Another relief factor is the water temperature. Josep M. Gili, researcher at the Institute of Sea Sciences (ICM-CSIC), stresses that water heating is modifying the usual scenario. According to the same source, temperatures have been persistently high, with registrations of 22 degrees in Cantabria and 23 in the Basque country. These values favor the permanence of colonies by the coast and increase the probability of contact with bathers.
Impact of human activity on the marine ecosystem
Although global warming plays a central role in this phenomenon, it is not solely responsible. According to Gili, it would be a mistake to ignore the cumulative effects of human activity on marine ecosystems. The reduction of natural predatory species, such as turtles, moonwords, sea snails and sea bumps, has unbalanced the system, allowing the increase of organisms such as the Portuguese caravel.
According to biologist Lourdes González, the loss of biodiversity, caused in part by pollution and overweight, contributes to this imbalance. The decrease of direct predators reduces natural control over Physalia Physalis populations, favoring their expansion.
Dangerous but rare lethal
The Portuguese caravel is known for its particularly painful and dangerous bite. Its tentacles, which can reach up to 30 meters in length, have hives with powerful poison. As Gili explains, symptoms may include intense irritation, itching, sweating and tear. In rarer cases, it can cause severe reactions, although most situations do not pose life -threatening.
In case of contact, it is recommended to wash the affected area with salt water and apply local cold to mitigate the effects of poison. It is also advised to use freshwater, which can aggravate toxins release.
Prevention and warning signs for bathers
One of the characteristics of this species that facilitates its detection is the visible presence of the floating candle with bluish tones and purple. According to Gili, this aspect allows bathers to avoid water when they see the body. However, it also warns of residual risk: Loose tentacles may remain active for hours, and it is recommended to avoid bathing up to 24 hours after last sighting.
The use of sunscreen may slightly reduce the impact of the bite, creating a layer of protection on the skin, although this measure does not replace the precaution of not entering water when there is warning of the authorities.
Similar effects on the Mediterranean
The same phenomenon has been observed in other coastal areas, namely in the Mediterranean. As referred to in, Medusa Rhizostoma pulmknown as white medusa, is reproducing itself early and prolonging its presence in the coastal waters, sometimes until October. This change is also linked to rising sea temperature, which alters the natural development cycles of the species.
While ten years ago there was only one annual reproduction cycle of this jellyfish, at least two cycles per year are now observed, indicating a structural change in ecological dynamics.
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