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Peru’s rare and endangered Titicaca water frogs are in even more trouble now, after 10,0000 of them turned up dead along the Coata River in Puno.

The river, which feeds into Lake Titicaca, serves as a water source for a number of villages in the region, but it is also used as a dumping site by locals, according scientists in the field working with the Denver Zoo to preserve the endangered amphibians.

“We’ve been following these frogs since the beginning of their decline in 2007,” Tom Weaver, an assistant curator at the zoo, told Fox News Latino.

About a week ago, approximately 10,000 dead “scrotum” frogs – as they’re called because of their wrinkled skin – were discovered by Peru’s wildlife and forestry service, Serfor.

The Titicaca frog (Telmatobius culeus) is listed as critically endangered by the International Union for Conservation of Nature (IUCN) on their red list of threatened species.

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“Historically, the frogs have being harvested and smuggled into Lima and Cusco, and people grind them up in blenders and drink them," Weaver said. "They're used to make what's locally called 'Peruvian Viagra.' But in more recent years, the lake water has declined – which is a bigger problem.”

Telmatobius culeus is the world’s largest aquatic frog. It lives near Titicaca, the world’s highest-altitude navigable lake, which lies about 12,500 feet above sea level.

Weaver told FNL that in 2014 there was a big die off of the frogs – the water was turning green, but he says this recent find is one of the biggest he’s aware of.

Weaver says it isn't clear why the frogs died, but runoff from illegal gold mining, livestock sewage and human encroachment (including the use of disinfectants and pesticides) are the likeliest culprits. During the rainy season, he says, all the toxins drain down into the lake.

“We’re calling this a global amphibian crisis," he added. "We’re losing 30 to 40 percent of 6,000 species worldwide that are in decline.”

He went on, “Frogs are called an 'indicator' species, meaning they absorb anything in their environment. Kind of like the canary in the coal mine ... Human interaction is negatively affecting the species. At one time, the frog was a top predator and then rainbow trout was introduced, replacing it.”

According to the Guardian, local anti-pollution campaigner Maruja Inquilla Sucasaca took 100 of the dead frogs to the main square in Puno to draw attention to their death.

“Lake Titicaca used to be a paradise, now we can’t use the water, and our livestock die if they drink it,” she told the Guardian. “Untreated sewage is being pumped into the lake from the big towns, and authorities don’t care.”