Bioluminescent 'Mar de Ardora' lights up Galicia's Rías Baixas

The coast of Galicia's Rías Baixas has experienced a striking bioluminescent display known locally as the "mar de ardora." The glow is caused by massive concentrations of the dinoflagellate Noctiluca scintillans, which emit light as a defensive response when the water is disturbed. Marine researcher Francisco Rodríguez of the Vigo Oceanographic Centre (IEO‑CSIC) explained that the phenomenon is most visible from late May to September, especially in spots such as the Cíes Islands, Aldán, O Grove and the beach of A Lanzada in Sanxenxo. When waves break or boats pass, the organisms light up, creating blue‑neon flashes that attract attention from tourists and locals alike.