Dozens of Alaska's rivers and streams are turning orange. The staining could be the result of minerals exposed by thawing permafrost and climate change, finds a new study.
Those orange streams can be problematic both in terms of being toxic but might also prevent migration of fish to spawning areas."O'Donnell first noticed an issue when he visited a river in 2018 that appeared rusty despite having been clear the year prior. He began asking around and compiling locations while grabbing water samples when possible in the remote region, where helicopters are generally the only way to access the rivers and streams.
"Chemistry tells us minerals are weathering," Poulin said."Understanding what's in the water is a fingerprint as to what occurred." While O'Donnell first noticed a change in 2018, satellite images have turned up stained waters dating back to 2008. More work is needed to better understand the problem and whether rivers and streams can rebound, perhaps after cold weather promotes permafrost recovery.