Biologist Ester Serrão, from the University of Algarve, warned today about the “very serious problem” that the invasive macroalgae “Rugulopteryx okamurae” can cause for tourism, rendering beaches unusable due to the large amount of biomass in the sand.
Currently, many beaches in the Algarve are only open to swimmers because municipal councils are rushing to clean them of the seaweed that remains on the sand. "If the councils didn't remove anything, it would be a total disaster," dhe assured.
The invasive species is also harming fishing. There are fishermen in the Algarve who don't go to sea, and others who bring in as much seaweed as fish in their nets, she said.
Ester Serrão, a professor at the University of Algarve and a researcher at CCMAR (Center for Marine Sciences) in the field of genetic diversity and the evolution of marine populations, from microorganisms to seaweed forests, spoke about the algae that has reached Portuguese shores in recent years and has already led the Government to approve a national strategy for managing the invasive species.
Ester Serrão and fellow biologist Rui Santos, also from the University of Algarve, were the first to detect “Rugulopteryx okamurae” on the mainland in 2001.
While monitoring algae on the Portuguese coast, following up on work from the previous year, they detected the algae on Dona Ana Beach in the Algarve. In large quantities. And the other algae species were no longer present.
According to the biologist, at that point, there was nothing that could be done. The proliferation of the invasive algae was such that the accumulating biomass left areas without oxygen. "The algae caused everything to die."
The biomass that accumulates on beaches, carried by currents, also damages the sand. Removing this accumulated biomass with machinery is the solution for now, but not the best, because the sand also goes with the algae. And then, she said, the problem is where to dispose of the biomass, if there are landfills that no longer accept algae.
Biomass—pieces of seaweed that break off—is found in protected areas of the beaches. According to Ester Serrão, "mountains" of it, taller than a person, have been created at Praia da Rocha.
In the Algarve, according to the biologist, there is a company that is looking for a way to remove the biomass while it is still at sea, which is not easy due to the large quantity throughout the body of water and the speed at which the algae reproduces.
“In calm water conditions, the spores cling to any hard structure, and when this happens, they cover everything, even corals, killing them, and they also kill other algae, taking up all the space and blocking out sunlight.”
Ester Serrão warns that the algae is spreading along the entire coast and has already reached Galicia. She says that the invasive species are often spread by fishing boats and even by aquaculture and maritime navigation. She guarantees that, compared to other invasive algae, the problem of this invasive species "is in fact very, very, very serious."
For now, she says there's nothing to do, just monitor and clean the beaches, as Spain has been doing for years, and there are no reports of toxic conditions for humans.
There is, she says, an investment in finding solutions, in understanding what to do with the biomass. However, he notes that because "Rugulopteryx okamurae" is classified by the European Union (EU) as an invasive species, the EU itself prohibits its economic use, although this does not prevent research.
The expert says, however, that based on current knowledge, the algae “does not have much use.”
