Source composition and seasonal variation of particulate trace element fluxes in Prydz Bay, East Antarctica.

ABSTRACT

Particulate fluxes of trace elements (Al, Fe, Mn, Cu, Pb, Zn, Cd and Co) in the polynya area of Prydz Bay were measured using time series sediment trap lasting from December 16th 2010 to December 16th 2011. The comparison of annual fluxes from different regions, the seasonality and sources of trace element, and their association with organic matters were investigated. The fluxes of Cu, Zn and Cd in the polynya area of Prydz Bay are dominated by marine biogenic sources. Their similar seasonality with the export of biological materials (biogenic silica, organic carbon, and calcite carbonate) is strongly related to the ice coverage and biological production. Mineral debris derived from Antarctic continent is suggested to account for the particulate fluxes of Al, Fe, Mn, Pb and Co in the polynya. Their seasonal variations are most likely controlled by ice melting and freezing process. Furthermore, their fluxes are also influenced by scavenging onto biogenic material for Pb and uptake by phytoplankton for Co. The excess fluxes of Cu, Zn and Cd have good relationship with organic carbon export. The coupling patterns are mainly regulated by source composition of trace elements and non-lithogenic input from atmospheric deposition or upwelling, and partly influenced by biological uptake process.