High Levels Of Mercury Found In Fish In Remote National Parks
Unhealthily high levels of mercury have been found in fish in national parks in Alaska and the West, proving that even the most remote lakes and streams in the U.S. aren’t immune to mercury pollution.
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.
The researchers said in their report that the levels of mercury in some national parks were alarming because they occurred in small fish — organisms that should have the least amount of mercury in their systems, because the higher fish are on the food chain, the more mercury they’re expected to have.
Zion, Capital Reef, Wrangell-St. Elias, and Lake Clark National Parks all contained sites in which most fish exceeded benchmarks for the protection of human and wildlife health,” the report reads. “This finding is particularly concerning in Zion and Capitol Reef National Parks because the fish from these parks were speckled dace, a small, invertebrate-feeding species, yet their Hg [mercury] concentrations were as high or higher than those in the largest, long-lived predatory species, such as lake trout.”
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http://thinkprogress.org/climate/2014/04/18/3428394/mercury-fish-remote-national-parks/