National Water-Quality Assessment (NAWQA) Program
What controls concentrations of mercury in stream water, sediment, and fish?
How do biological, chemical, and other environmental characteristics govern the methylation, transport, and bioaccumulation of mercury in streams?
This study includes stream ecosystems in relatively undeveloped forested areas and in highly urbanized areas to allow comparisons among contrasting land uses. The study also covers a wide range of landscapes with varying geology, climate, hydrology, and wetland density to better understand environmental factors controlling methylation, mercury transport, and bioaccumulation. The selected stream ecosystems vary in food-web complexity, which can also influence mercury biomagnification.