Environ. Sci. Technol. 2009, 43, 5652–5659
Submarine Groundwater Discharge of Total Mercury and Monomethylmercury to Central California Coastal Waters F R A N K J . B L A C K , * ,†,‡ A D I N A P A Y T A N , § K A R E N L . K N E E , §,| N I C H O L A S R . D E SIEYES,⊥ PRIYA M. GANGULI,† ELLEN GRAY,§ AND A. RUSSELL FLEGAL† WIGS Laboratory, Department of Environmental Toxicology, and Institute of Marine Sciences, University of California, Santa Cruz, California 95064, Department of Geological & Environmental Sciences, Stanford University, Stanford, California 94305-2115, and Department of Civil and Environmental Engineering, Stanford University, Stanford, California 94305-4020
Received February 20, 2009. Revised manuscript received May 12, 2009. Accepted May 14, 2009.
Fluxes of total mercury (HgT) and monomethylmercury (MMHg) associated with submarine groundwater discharge (SGD) at two sites on the central California coast were estimated by combining measurements of HgT and MMHg in groundwater with the use of short-lived, naturally occurring radium isotopes as tracers of groundwater inputs. Concentrations of HgT were relatively low, ranging from 1.2 to 28.3 pM in filtered groundwater, 0.8 to 11.6 pM in filtered surface waters, and 2.5 to 12.9 pM in unfiltered surface waters. Concentrations of MMHg ranged from
