FLUXES OF CD, CO, CU, FE, MN, NI, PB, AND ZN THROUGH THE STRAIT OF DOVER INTO THE SOUTHERN NORTH-SEA

Measurements of dissolved and particulate Cd, Co, Cu, Fe, Mn, Ni, Pb and Zn have been made on a regular basis over a fifteen month period at stations across the Strait of Dover, as a part of the Fluxmanche programme. These measurements have been integrated with data on fluxes of water and suspended particulate matter also obtained within the Fluxmanche programme to provide estimates of fluxes of these elements into the southern North Sea. For Fe, Mn, and Pb, particulate fluxes are greater than dissolved fluxes, whilst the reverse is true for Cd, Cu and Ni. Significant daily changes in magnitude of the modelled fluxes of water through the Strait when combined with averaged metal concentrations over longer timescales, result in large changes of fluxes of metals on a day to day basis. However, relatively small changes are evident for integrated autumn fluxes of metals for consecutive years using the available database. The annual fluxes of dissolved plus-leachable particulate metals through the Strait of Dover relative to the most recent estimates of riverine and atmospheric inputs to the North Sea were in the order Cu (44%) > Cd (39%) > Zn (16%) > Pb (11%).