Rusting Rivers: Heavy Metals and Visible Color Changes

Rusting rivers are increasingly common in the Brooks Range of northern Alaska. The orange stream color reflects oxidized iron (hence the appearance of rusting), but orange color also indicates elevated heavy metal concentrations and impaired water quality. Our ongoing study aims to document these occurrences, quantify toxic metal concentrations and loads, determine how the interaction of geology, hydrology, and permafrost degradation contributes to the phenomenon, and understand the consequences for stream biota, especially fish.