www.thinkprogress.org/climate/2014/04/18/3428394/mercury-fish-remote-national-parks/
"Researchers from the U.S. Geological Survey and National Park Service released a report Thursday that found 5 percent of the freshwater fish sampled in 21 western national parks had levels of mercury that were high enough to trigger toxic responses from the fish themselves, potentially endangering their health and lives. In addition, 35 percent of the fish sampled had enough mercury in them to impact the health of some predatory birds, and 68 percent of fish had mercury levels above the recommended amount for “unlimited consumption” by humans."
