The vote, held on Friday, was the sudden climax of a long fight over development on the sandy coast south of Lisbon. The new law bars construction across the reserve and gives the government authority to buy out three unbuilt hotel sites. Supporters cheered from the public gallery as the result was announced: 145 votes in favour, 70 against and 15 abstentions.
The dispute had stalled since 2024, when ministers proposed a smaller dune buffer and local councils objected to limits on tourism permits. Then, from 15 September, waves began glowing electric blue after dark along a stretch of beach and estuary. Thousands came to see it, and the government’s compromise quickly became much harder to defend.
The glow along the dunes
The light appeared on 12 nights, sometimes tracing the surf in bright, wavering lines. Local estimates put the number of visitors at 38,000, with cars backed up on roads leading to the beach and residents sharing photographs of the glow before dawn. By 1 October, videos and long-exposure pictures had travelled far beyond the Algarve and Lisbon.
Marine ecologist Helena Schmidt, who collected water samples at three sites, said the likely source was bioluminescent plankton, but researchers had not explained why the display was so intense or why it followed such a long stretch of shore. “We can identify the kind of light-producing organism, but not what made this particular bloom spread in that pattern,” she said. Tests found no immediate health concern; officials advised visitors not to collect or drink seawater.
For years the dunes were treated as empty space on a planning map. The blue nights made people look again.
Akande Abodunrin, coastal photographer
The sudden attention strengthened the case made by residents and conservation groups for keeping buildings back from the dunes. The new boundary includes salt marsh, pine scrub and freshwater pools beside the Tagus estuary. It also leaves the beach open to the public, with seasonal limits on vehicle access and new paths intended to keep foot traffic off fragile sand ridges.
A vote with real costs
The government expects the buyouts and restoration work to cost €38 million (about $44 million) over four years. Peetu Ervola, a shopkeeper near the beach, said the decision brought relief after years of uncertainty over the permits. “People came here to watch the water, not to see another wall of holiday flats,” he said. Businesses are asking the government to publish details of the compensation timetable.
Azevedo’s black-and-white photographs of Portugal’s dunes, made in the 1960s, were shown at public hearings during the dispute. The fictional archive has long been used by campaigners to argue that the coast is worth protecting for its own sake. This month, local photographers created a new record: dated images of the glowing surf, paired with shots of the dunes behind it.
Schmidt cautioned that the bloom should not be treated as evidence that the coast is permanently changing; similar displays can depend on short-lived combinations of water conditions and plankton. The government has ordered a year of monthly sampling and will review visitor access before next summer. For now, the glow has faded, but the legal boundary that it helped bring about is in place.
