It may look like an otherworldly phenomenon from an alien planet, but a lagoon in Argentina that has turned bright pink is the result of very human activities.
The body of water in Argentina's Southern Patagonia region turned pink last week, in a striking but worrying development that experts and activists are blaming on pollution. The discolouration of the water is believed to be caused by the chemicals used by nearby factories to preserve prawns and seafood for export.
Sodium sulphite is an antibacterial compound commonly used in fish factories. By law, it should be treated before being dumped, but it is being blamed for contaminating the Chubut River that feeds the Corfo lagoon and other water sources in the region.
"Those who should be in control are the ones who authorise the poisoning of people," said environmental activist Pablo Lada.
The lagoon, which is not used for recreation, receives run-off from the Trelew industrial park and has changed colour before. Residents of the area have long complained of unpleasant smells and other environmental issues around the river and lagoon.
In recent weeks, residents of Rawson, in neighbouring Trelew, blocked roads used by lorries carrying processed fish waste through their streets to treatment plants on the city's outskirts. "The reddish colour does not cause damage and will disappear in a few days," environmental control chief for Chubut province, Juan Micheloud, said last week.
Sebastian de la Vallina, planning secretary for the city of Trelew disagreed. "It is not possible to minimise something so serious."