Mercury Dispersal from Lode Sources in the Kuskokwim River Drainage, Alaska

Abstract

The Kuskokwim River is not industrially polluted, but it does have an anomalous mercury content due to cinnabar particles in bottom sediments near natural mineralized sources; the mercury content is rapidly diluted downstream by physical mixing with other sediments. Mercury anomalies extend the greatest distance downstream in the tributaries, the finest size fraction of bottom sediment, the river-bank deposits, the suspended sediment, and water; the last two of these categories contribute the bulk of the mercury to the marine environment.