Arctic Mercury Levels Lower Than Previously Thought! Thanks To Collapse Of Soviet Union
The most recent research suggests that the mercury concentration in fish is much lower than expected in much of the continental Arctic, and the Soviet Union may have something to do with it.
Researchers found that mercury contaminations varied throughout the Arctic based on "atmospheric, geological, and biological conditions."
"It turns out that the economic decline of the former Soviet Union, which collapsed in 1991, appears to have been good for the Arctic environment in that part of the world," Leandro Castello, an assistant professor of fish and wildlife conservation in the College of Natural Resources and Environment at Virginia Tech, said in a statement.
Atmospheric mercury comes largely from ore processing and mining, such as smelting, according to a United Nation's environmental program study. Under certain water conditions, mercury can be converted into a substance that can be absorbed by living species through a process called methylation.
"Methylmercury is highly toxic," Castello said.
The team found that burbot fish, cod-like sea creatures found in the Russian Lena and the Mezen rivers were safe to consume while Pasvik River fish and those living in the Canadian Mackenzie River were highly contaminated.
Burbot fish are a non-migrating species.
"The burbot fish was chosen because they are top predators that integrate many bio-geo-chemical processes in the river watersheds," Castello said. "The fish were collected downstream of the watersheds, so that they would present everything that happened upstream."
Mercury levels in the Lena River were among the lowest.
"Good news since the Lena River is one of the largest watersheds in the world," Castello said.
Until the 1970s, atmospheric mercury was on the rise because of the industries in Europe and in North America, but emission control started to reduce the trend, the paper explains.
In Russia, metallurgic industries in Murmansk region help explain the contamination in the Pasvik River, but economic issues near the Lena and Mezen rivers lowered the pollution rate.
A confounding factor has been global warming because it makes mercury more available to fish.
"There are no ancillary environmental data from the time period of the study in Russia, [but the differences across the Arctic] may be explained by differences in water quality, geological bedrock formations, and proximity to polluting sources," Castello said.