El Salvador Lagoon Turns Bright Turquoise | Scientists Link Rare Bloom to Heatwave Conditions | WION

Added: 2026-05-27

[00:00:00]A lagoon in central El Salvador has turned a bright turquoise color drawing tourists and attention from a scientist and officials say the unusual transformation is linked to a bloom of cyanobacteria caused by high temperatures and intense sunlight. The Pacific Lagoon around 70 km east of San Salvador has recently changed from its usual shades of green and brown to a vivid turquoise.

[00:00:27]El Salvador's environment ministry says the color shift is being caused by cyanobacteria, microscopic organisms also known as blue-green algae. Experts say strong sunlight, high temperatures, and alkaline water conditions helped trigger the bloom. Now while no health alert has been issued, officials warn that some cyanobacteria can produce toxins that may cause skin irritation or respiratory problems and despite concerns the lagoon has become a tourist spot. With visitors arriving to photograph and explore the unusual water, researchers from the University of El Salvador say the striking color comes from the interaction between sunlight and the microorganism in the water. And scientists also confirm that the lagoon is a volcanic crater like a lake around 44 m deep with no signs of mineral irregularities or external contamination. Locals say fish in the lagoon remain healthy while boat operators report a rise in tourism. The turquoise lagoon is now boosting local businesses while scientists continue monitoring the rare environmental phenomenon.