World Lake Day was marked on 27 August with a reminder of the challenges facing lakes worldwide, including El Salvador’s Lake Suchitlan. Once known for its biodiversity and as a hub for fishing and tourism, the country’s largest reservoir is now heavily overrun by an invasive aquatic plant.
Fed by the Lempa River and covering 13,500 hectares, the artificial lake was created in the 1970s to supply the Cerron Grande hydroelectric power station. But in recent years, its surface has been taken over by Pistia stratiotes, or water lettuce, a floating plant that thrives on chemical pollution carried into the reservoir by tributaries. Wind and heavy rains have accelerated its spread, leaving the lake looking more like a bright-green field than open water.
This Copernicus Sentinel-2 image, captured on 13 August 2025, shows Lake Suchitlan almost completely covered. The green colouring points to dense aquatic vegetation, whose presence disrupts habitats, harms fish populations, and impacts the many species that depend on the wetland.
The consequences have been severe for local communities. “The truth is that the (plant) has affected us every year, but now it has gone too far. Today it’s completely covered,” Julia Alvarez, a 52-year-old boat operator, told AFP. Fishing has stalled, boatmen have been left without income, and lakeside restaurants report dwindling visitors. “Today, people just come, look, and leave right away. They don’t enjoy the rides, they don’t stay to taste the dishes, because the attraction is the water, the lake,” said waiter Johnny Anzora.
Five dredging barges have been deployed to remove the vegetation, clearing about 6.3 hectares so far. Yet researchers warn that unless pollution flowing into the reservoir is curbed, efforts to eradicate the plant will only provide temporary relief.
Featured image credit: European Union, Copernicus Sentinel-2 imagery
