Researchers are investigating a curious mass die-off of some 10,000 endangered frogs in Peru in a river near the border with Bolivia that local organizations claim suffers contamination that has long been ignored by authorities.
The giant frog species is endemic the Lake Titicaca—one of the largest bodies of water in South America, shared between Bolivian and Peruvian territory—and its surrounding river system. The rare water frogs were found dead by the thousands along more than 30 miles of the banks of the Coata River, which feeds into Titicaca.
Peru’s National Forest and Wildlife Service, known as Serfor, released information about the die-off last Friday and confirmed that the mysterious phenomenon is under investigation by experts.
Scientists and environmental defenders in the area suspect that the sudden die-off is linked to contamination in the water system. A local activist working against pollution in the region, Maruja Inquilla, reported the incident to Serfor, prompting further investigation.
“I was forced to bring in the frogs that died because the authorities don’t realize the what we are living, they have no idea of the magnitude of the contamination,” Inquilla, a member of the local Committee Fighting Against Contamination of the Coata River, told AFP. “The situation is desperate.”
Researchers have collected samples to pinpoint the cause of death of the frogs. By the time scientists got to the frogs to conduct an official count, birds such as gulls were already feasting on the thousands of dead amphibians, according to Serfor.
Robert Elias, Peru program manager for U.S.-based Denver Zoo and one of the researchers involved in the investigation after having studied the frogs since 2010, told the Guardian that such “high mortality so quickly” could have been caused by contaminants in the river, possibly stirred up by local garbage clean-up initiatives.
Parts of Lake Titicaca, the world’s highest navigable lake, and the surrounding area are heavily polluted. Local resident argue that sewage and water treatment plants are desperately needed to filter out dangerous toxins that trickle into the lake from the nearby city of El Alto, a major industrial hub. Runoff from mining operations and agricultural production in the region are also sources of contamination.
The giant Titicaca water frog—technically known as Telmatobius culeus and nicknamed the “scrotum frog” for its wrinkly, oversized skin that helps the 2.2-pound amphibian breath at high altitude—is one of many endemic species to the lake’s ecosystems.
According to the IUCN Red List of Threatened Species, the Titicaca water frog is critically endangered, and the 10,000-frog die-off could be a major hit to the species.