1000s Of Tons Of Invasive Brown Algae Buries Beaches In Spain, Around Strait Of Gibraltar
Ed. - NOTE - the Guardian refers throughout to the invasive as algae and seaweed, which is confusing. Using Teh Google, I discovered that Rugulopteryx is considered an algae, though it looks plant-like. Anyway . . .
Thousands of tonnes of an aggressive invasive seaweed from south-east Asia are piling up on the beaches of the strait of Gibraltar and Spain’s southern coast in what local environmentalists say is a major threat to the region’s biodiversity.
Since May, the local authority in Cádiz has removed 1,200 tonnes of the alga Rugulopteryx okamurae from La Caleta, the city’s most popular beach, including 78 tonnes in a single day. “We’re completely overwhelmed. This is an environmental catastrophe,” said José Carlos Teruel, responsible for Cádiz city council’s beaches. “Whenever the wind is westerly, we know we’re in for another wave of seaweed.”
As with many other invasive marine species, the alga is thought to arrive in the ballast tanks of ships which pass through the Suez canal and then discharge their tanks in the Mediterranean. In little more than a decade the species has colonised the strait of Gibraltar, much of Spain’s southern coast, the Canary Islands, the Azores, and, farther north, the Cantabrian sea and the Basque Country.
“It was first spotted 10 years ago in Ceuta, Spain’s north African enclave, by a researcher from Málaga university, but the authorities are always too slow to react,” said Juan José Vergara, a professor of biology at the University of Cádiz. “In the first phase of an invasion such as this it can be controlled. It’s like catching cancer early on before it spreads,” Vergara said, adding that what washes ashore is a fraction of what is underwater. “But now the scale of it makes it impossible to control. In other seaweed invasions we’ve seen things revert to normal after a period of 10-15 years but many scientists say they’ve never seen an invasion on this scale.”
EDIT
https://www.theguardian.com/environment/2025/jul/27/thousands-of-tons-of-invasive-seaweed-overwhelming-spanish-beaches