Pollution in Argentina’s Rivers Causes Dolphins to Turn Green, Dead Fish to Float

On February 13, dolphins with hair dyed bright green appeared along the Uruguay River north of Buenos Aires, Argentina, with a putrid odor and a large number of dead fish on the banks. The annual cyanobacterial layer covering the river around the Salto Grande hydroelectric dam has been getting worse in recent years, and the green tide occurred at a time when at least 15 municipalities in the province of Buenos Aires issued health alerts. A week earlier, creeks near Buenos Aires had also turned blood-red and emitted a foul odor, which residents suspected was linked to the discharge of waste from the plant and which was being investigated by environmental authorities.