‘Red tide’ leads to swimming ban between Faro and Vilamoura

A swimming ban is in place on all beaches between Faro and Vilamoura due to the potential dangers of microalgae which have been found in the water and have turned part of the Algarve’s coastline into a ‘sea of red’.

The microalgae were first detected on Sunday by the Portuguese Environmental Agency (APA) which has collected samples for testing. The results should only be known “in a few days”, says APA boss José Pacheco.

APA is concerned that the microalgae could “potentially have harmful effects on humans” and has advised beachgoers to stay out of the water until the results of the tests are known. Due to APA’s warning, the national maritime authority (AMN) placed a swimming ban on all beaches between Ilha de Faro and Praia da Rocha Baixinha.

Fishing is allowed but discouraged, with maritime authorities advising people to not eat fish or shellfish that has been captured in the affected waters.

Meantime, conflicting opinions are being reported in the national press about the risks to health of the microalgae.

Lígia Sousa, a researcher from the Faculty of Science and Technology of the University of Lisbon, told Observador newspaper that the microalgae can create “toxic substances which are harmful to humans” when they form colonies.

But according to Alexandra Teodósio, a marine biologist and vice-rector of the University of Algarve, the microalgae are harmless and should not be seen as a threat.

In fact, she told TSF radio that this kind of microalgae is an “attraction in some parts of the world, such as Thailand”, where people pay to see how the sea turns a bright red at night.

Red tides are common
Faro port captain Nuno Cortes Lopes has seen many of these ‘red tides’ before, although none of them has spanned such a large area as now.

Speaking to Observador newspaper, he explained that beach concessions were told to raise red flags on the affected beaches due to the recommendations made by APA and that a decision to maintain or lift the swimming ban will only be made when the test results are revealed.

He also explained that the microalgae can only have adverse effects if they are swallowed.

“They are harmless when in contact with the skin.”

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Photos: TIAGO DURO