Fig. 3.

Illustration of the conversion of inorganic mercury [Hg(II)] to MeHg by anaerobic bacteria, biomagnification of MeHg at successive marine trophic levels, and then reintroduction of MeHg to the base of the food chain via top-down contamination. Images are courtesy of the Environmental Molecular Sciences Laboratory (EMSL), a Department of Energy Office of Science user facility at the Pacific Northwest National Laboratory (anaerobic bacteria); Richard R. Kirby, Secchi Disk project (phytoplankton); Maria Grazia Mazzocchi, Stazione Zoologica Anton Dohrn, Italy (zooplankton); and FishWatch, National Oceanic and Atmospheric Administration (prey fish).