Deep-Sea Research II 46 (1999) 979}990 Silver in the far North Atlantic Ocean I. Rivera-Duarte*, A.R. Flegal, S.A. San  udo-Wilhelmy, A.J. Ve H ron Earth Sciences Department/WIGS, University of California, Santa Cruz, CA 95064, USA Environmental Toxicology/WIGS, University of California, Santa Cruz, CA 95064, USA Marine Sciences Research Center, State University of New York, Stony Brook, NY 11794-5000, USA CEREGE, UMR CNRS 6635, BP80, 13545 Aix en Provence Cedex 4, France Received 15 March 1998; received in revised form 30 October 1998; accepted 10 November 1998 Abstract Total (un"ltered) silver concentrations in higher latitudes of the North Atlantic (52}683N) are reported for the second Intergovernmental Oceanographic Commission (IOC) Global Invest- igation of Pollutants in the Marine Environment (GIPME) baseline survey of 1993. These silver concentrations (0.69}7.2 pM) are oceanographically consistent with those (0.24}9.6 pM) pre- viously reported for lower latitudes in the eastern North and South Atlantic (Flegal et al., 1995). However, surface ()200 m) water concentrations of silver (0.69}4.6 pM) in the northern North Atlantic waters are, on average, ten-fold larger than those (0.25 pM) considered natural background concentrations in surface waters of the central Atlantic. In contrast, variations in deep far North Atlantic silver concentrations are associated with discrete water masses. Consequently, the cycling of silver in the far North Atlantic appears to be predominantly controlled by external inputs and the advection of distinct water masses, in contrast to the nutrient-like biogeochemical cycling of silver observed in the central Atlantic and Paci"c oceans.  1999 Elsevier Science Ltd. All rights reserved. 1. Introduction There are relatively few measurements of silver concentrations in the World Ocean. These include reports on the distribution of silver in some oceanic (Murozumi, 1981; * Correspondence address: SPAWAR Systems Center, Environmental Sciences Division Code D361, 53475 Strothe Rd., San Diego, CA 92152, USA. Fax: 001-619-553-6305. E-mail address: iriverad@spawar.navy.mil (I. Rivera-Duarte) 0967-0645/99/$ - see front matter  1999 Elsevier Science Ltd. All rights reserved. PII: S 0 9 6 7 - 0 6 4 5 ( 9 9 ) 0 0 0 1 2 - 0