Alaskan rivers are turning orange

From the article:

“More than 75 streams and rivers have changed in their chemistry, and it has implications for aquatic health and rural communities,” said Brett Poulin, one of the study’s researchers and an assistant professor of environmental toxicology at the University of California at Davis. “It’s likely a climate-change-driven phenomenon.”

The study, published this week, was a collaboration between the university, the U.S. Geological Survey and the National Park System. Researchers have since observed more rivers running orange and plan to return to the sites to measure changes to the area’s water quality and ecology, Poulin said. While much remains unknown, researchers said the shifts are alarming and suggest possibly dire consequences for the health of Alaskan rivers and rural communities.

Researchers said the changes could be the result of melting permafrost — propelled by climbing temperatures — which released naturally occurring sulfide minerals into the water. When these minerals, including iron, slip into the water, they react with oxygen and effectively rust, turning clear streams bright orange.

“As thawing is occurring in the soil, those minerals that have been locked away get into the water,” Poulin said. “The deeper the soil thaws, the further the water infiltrates.”

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There are two major implications that researchers are concerned about, Poulin said. “The first is ecological: Some of the metals being released can be acutely toxic to organisms.”

The second is what it may mean for rural communities, many of whom regularly fish for survival, he said. “Subsistence fishing is recognized as a major part of their culture and lifestyle,” and compromised rivers would have cascading effects on rural and indigenous communities’ fishing practices.