Peru River Otters Recovering but Still Threatened

Given that giant river otters survive entirely on fish and live their whole lives in freshwater habitats, one of the most worrisome threats to the species; survival is mercury poisoning from an epidemic of gold mining in the region. 

“The extent of gold mining in the Madre de Dios region increased from less than 10,000 hectares in 1999 to more than 50,000 hectares in 2012,” Groenendijk said, pointing to a recent study that found that “total mercury levels in 68 percent of fish muscles [in Peru] exceeded the tolerable level for the European otter (Lutra lutra) and 17.6 percent exceeded…the common standard for human consumption.” 
http://www.theepochtimes.com/n3/1020607-peru-river-otters-recovering-but-still-threatened/