Scientists have recently discovered that high levels of mercury and selenium exist in Grand Canyon fauna. According to a new study, the chemical levels were discovered by the U.S. Geological Survey (USGS), and were published in a report in the Environmental Toxicity and Chemistry journal.
HOW THE MERCURY IS REACHING THE GRAND CANYON
Researchers have said that the mercury, aside from being partially the product of air pollution in the region, originates from Lake Powell’s algae, which eventually comes to the Grand Canyon carrying the neurotoxin with it, according to Discovery News. The amount of selenium and mercury found in the Grand Canyon’s food webs are far beyond levels that indicate a threat to the wildlife. Unfortunately, managing the level exposure is difficult because the sources of the chemicals “extend far beyond Grand Canyon boundaries,” David Walters, the study’s lead author and USGS ecologist, told Discovery News.
RAINBOW TROUT IS STILL EDIBLE
At high levels, mercury is dangerous for human consumption. However, the mercury levels in the fish studied was actually below the threshold that makes consumption dangerous. Rainbow trout, the species most commonly studied by the researchers, contained mercury levels deemed by the Environmental Protection Agency to be acceptable for eating.
“Every fish we looked at from Glen Canyon was way below any risk threshold and the fish we looked at downstream were way below that threshold as well, so it doesn’t appear to be any risk to humans through consumption of trout,” Ted Kennedy, one of the study’s authors, told the AZ Daily Sun.
HOW THEY STUDIED IT
Scientists analyzed data from sites by the Colorado River, which passes through the Grand Canyon and influences its ecosystem. They measured the selenium and mercury levels in fish and other species.
NEGATIVE EFFECTS OF MERCURY IN THE GRAND CANYON
Mercury has an extremely negative influence on wildlife. The National Wildlife Federation (NWF) defines the chemical as a “highly potent neurotoxin that impacts the function and development of the central nervous system in both people and wildlife.” You can read more about its effects on mammals, fish and birds on the NWF’s website here.
