A year on from one of El Salvador's most devastating environmental catastrophes, Lake Suchitlán remains shrouded in mystery. The once-thriving freshwater body, a Ramsar site and vital hydroelectric reservoir, was ravaged by thousands of dead fish washing ashore and an infestation of invasive water lettuce that covered nearly 70% of its 135 sq km surface. This ecological disaster has left local communities reeling, as well as the livelihoods of those dependent on fishing and tourism.
The scenes from July 2025 will be etched in the memories of villagers like Copapayo's residents for years to come: dead fish littering the shores, followed by an alarming proliferation of water lettuce. By August 2025, the lake was choked with plastic waste, more fish were dying, and those who made a living from fishing and tourism saw their incomes drastically decline.
Despite the severity of this crisis, the Salvadorian authorities under President Nayib Bukele's government have offered no official explanation for the collapse. Local fishers, typically earning around £11 per day, are struggling to adapt; many are joining clean-up crews or relying on family support. The deployment of military personnel to assist with the clean-up efforts underscores the scale of this environmental disaster.
The pollution has had a devastating impact on local tourism. Boat operators and guides in towns such as Suchitoto report a significant drop in visitors, who once flocked to Lake Suchitlán for boat tours, birdwatching, and lakeside dining. The water's opaque and foul-smelling state is deterring tourists, forcing many tourism workers to seek alternative employment and often earning significantly less than their previous income.
Scientists and environmental organisations had warned of the lake's decline for years, attributing it to untreated sewage, agricultural runoff, and lax enforcement of water quality regulations. Biologists point to severe nutrient overload, with high levels of nitrogen and sulphates from fertilisers entering the lake via the Lempa River. These conditions create an ideal environment for invasive plants like water lettuce to thrive, depleting oxygen, leading to fish die-offs, increased mosquito populations, and persistent foul odours.
Researchers from the University of El Salvador's toxicology laboratory (Labtox) were asked to analyse water samples weeks after the initial die-off. Their findings showed no anomalies in nutrient levels or active cyanobacterial blooms detected; however, they do not test for pesticides or herbicides, including highly poisonous chemicals such as paraquat. This raises questions about the scope of the investigation and whether crucial contaminants may have been overlooked.