FT: Venomous jellyfish-like creatures flood European beaches

Beaches along the Bay of Biscay in France and Spain are once again seeing an influx of Portuguese man o’ wars, jellyfish-like marine creatures with long, venomous tentacles, The Financial Times reports.

The report said the creatures get their name from their transparent blue, purple or pink inflated crests, which resemble the sails of 18th-century Portuguese warships.

Their venomous, stinging tentacles can extend up to 30 meters below the ocean’s surface.

Authorities along the Bay of Biscay in the Atlantic Ocean have warned in recent weeks that the species typically found in tropical waters has been appearing on European beaches that tourists and locals have used to cool down from a series of heatwaves.

Along France’s extensive Atlantic coastline, Portuguese man o’ wars have begun appearing every year rather than once every seven or eight years, said Elvire Antajan, who studies zooplankton at France’s national oceanographic institute Ifremer in Arcachon.

Warnings over jellyfish species traditionally seen in European waters are also in place along the Mediterranean coast, while in northern France an EDF nuclear reactor was still offline on Tuesday after a “massive arrival” of jellyfish clogged cooling pumps, following a similar incident last year.

Sightings of unwelcome jellyfish in Europe this year have coincided with a historic marine heatwave in the region and increased interest from researchers in the species’ ability to thrive in oceans warmed by climate change.

Scientists who collaborate on the World Weather Attribution project said on Wednesday that high temperatures in European oceans would have been “virtually impossible” without global warming.

Their modelling showed that climate change caused by the burning of fossil fuels last month added 2C to Mediterranean temperatures, 1.4C to a region centred on the Bay of Biscay and the Iberian Peninsula, and 1.3C to a Celtic region centred on the Irish Sea and the English Channel.

They also drew attention to the jellyfish phenomenon. John Bruno, a marine ecologist at the University of North Carolina at Chapel Hill who participated in the study, warned that extreme heat could lead to “mass mortality” events at sea for fish, birds and ocean mammals.

In contrast, jellyfish and related creatures could be more tolerant of temperature rises, leading them to “bloom” during some marine heatwaves even as other species decline, he said. The rubbery animals are also more resilient to low-oxygen or low-nutrient conditions triggered by warmer water, and benefit from overfishing of their predators.

By Bakhtiyar Abbasov