Copper in surface waters of the Bering Sea

Abstract

Copper concentrations have been measured in surface <75 m waters of the central Bering Sea. Concentrations of 2–4 nmole kg −1 were measured in the Zhemchung Canyon region where water depths are greater than 1000 m. Concentrations are higher 2–25 nmole kg −1 on the shallow <100 m continental shelf, inshore of a hydrographic front at the 100 m isobath. Copper-depth profiles on the continental shelf water mass are dominated by Cu concentrations increasing toward the sediments. These trends may be maintained by a flux of Cu from surficial sediments. A frontal system over the 100 m isobath acts to control the flux of Cu, a significant part of which apparently emanates from the sediments, between the continental shelf and the central Bering Sea basin. The benthic shelf Cu flux was constrained to be less than 3 nmole cm −2 yr −1.