According to research published in Nature Communications, global warming is threatening fish from the Yukon River. If CO2 emissions continue at current levels, so much mercury will flow out of the melting permafrost that the fish could become poisonous in a matter of decades.
The Yukon River is the largest river in northwest North America. More than half of its course is in Alaska, while the upper part flows mostly through the Canadian Yukon Territory, which this river takes its name from. The river is 3,185 km long and is the fifth largest watershed in North America, and its salmon is of great economic importance. According to researchers, without limiting greenhouse gas emissions, the concentration of mercury in fish in the Yukon River may exceed levels that are safe for human health by 2050. Such high mercury emissions from melting permafrost may persist for centuries, affecting the environment both locally and globally.