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Alaska’s Rivers Are Turning Orange
Context:
Rivers and streams in Alaska are changing color from clear blue to rusty orange, due to toxic metals released by thawing permafrost.
More on news:
- Researchers from the National Park Service, UC Davis, and the US Geological Survey conducted tests at 75 locations in Alaska’s Brooks Range.
- An aerial view of the Kutuk River in Alaska’s Gates of the Arctic National Park shows orange paint-like discoloration in the clear blue water.
- A study published in Water Resources Research details metal concentration increases across 22 mountain streams in Colorado’s Rocky Mountains over the past 30 years.
- Similar discoloration processes occur in parts of California and Appalachia with mining history, but it’s surprising to see in remote wilderness areas far from mining sources.
- The waterways have become rusty and cloudy over the past five to ten years.
Impact of Thawing Permafrost on Alaska’s Waterways:
- Some of the metals are toxic to river and stream ecosystems and causing the discoloration include iron, zinc, copper, nickel, and lead.
- Researchers attribute half of the increase to reduced streamflow, while the other half is from thawing permafrost allowing minerals to leach out of the bedrock.
- Arctic soils naturally contain organic carbon, nutrients, and metals, such as mercury, within permafrost.
- Thawing permafrost, accelerated by high temperatures, releases these minerals into water sources.
- The Arctic is warming four times faster than the rest of the world, contributing to this phenomenon.
- The most drastic colour changes occurred between 2017 and 2018, coinciding with record warm years.
- Study highlights this as an unexpected consequence of climate change.
Impact of Waterway Discoloration in Alaska:
- Declines in aquatic life.
- Concerns for drinking water and fishing.