Wild, scenic, and toxic: Recent degradation of an iconic Arctic watershed with permafrost thaw.

ABSTRACT: The streams of Alaska's Brooks Range lie within a vast (~14M ha) tract of protected wilderness and have long supported both resident and anadromous fish. However, dozens of historically clear streams have recently turned orange and turbid. Thawing permafrost is thought to have exposed sulfide minerals to weathering, delivering iron and other potentially toxic metals to aquatic ecosystems. Here, we report stream water metal concentrations throughout the federally designated Wild and Scenic Salmon River watershed and compare them with United States Environmental Protection Agency (EPA) chronic (4-d) exposure thresholds for toxicity to aquatic life. The main stem of the Salmon had elevated SO₄^2- concentrations and elevated SO₄^2-: Ca relative to a pr

SUBMITTER: Sullivan PF 

PROVIDER: S-EPMC12452937 | biostudies-literature | 2025 Sep

REPOSITORIES: biostudies-literature