Metal mobilization from thawing permafrost to aquatic ecosystems is driving rusting of Arctic streams

Communications Earth and Environment
By: , and 

Links

Abstract

Climate change in the Arctic is altering watershed hydrologic processes and biogeochemistry. Here, we present an emergent threat to Arctic watersheds based on observations from 75 streams in Alaska’s Brooks Range that recently turned orange, reflecting increased loading of iron and toxic metals. Using remote sensing, we constrain the timing of stream discoloration to the last 10 years, a period of rapid warming and snowfall, suggesting impairment is likely due to permafrost thaw. Thawing permafrost can foster chemical weathering of minerals, microbial reduction of soil iron, and groundwater transport of metals to streams. Compared to clear reference streams, orange streams have lower pH, higher turbidity, and higher sulfate, iron, and trace metal concentrations, supporting sulfide mineral weathering as a primary mobilization process. Stream discoloration was associated with dramatic declines in macroinvertebrate diversity and fish abundance. These findings have considerable implications for drinking water supplies and subsistence fisheries in rural Alaska.

Study Area

Publication type Article
Publication Subtype Journal Article
Title Metal mobilization from thawing permafrost to aquatic ecosystems is driving rusting of Arctic streams
Series title Communications Earth and Environment
DOI 10.1038/s43247-024-01446-z
Volume 5
Year Published 2024
Language English
Publisher Nature
Contributing office(s) Alaska Science Center Geography, Alaska Science Center Water
Description 268, 10 p.
Country United States
State Alaska
Google Analytic Metrics Metrics page
Additional publication details