MERCURY TRANSPORT IN WATERS OF THE STRAIT OF DOVER

The purpose of this work as part of the FluxManche EC Project (MAST-1) was to obtain accurate data on the concentrations and distributions of dissolved and particulate mercury which, together with determinations of suspended matter and water transport, can provide estimates of fluxes through the Strait of Dover. Samples were collected every other month between September 1990 and December 1991 at six stations, two depths being sampled at each station, on a transect between Folkestone and Cap Griz-Nez. Data concentrations were log-normal distributed. Geometric means were 2.65 and 3.36 pM for dissolved and particulate mercury, respectively. Mercury linked to particles constituted between 20 and 97% of total mercury, with the highest proportions being found near the coast similarly to the distribution pattern of particulate matter along the transect. On the basis of water and suspended particulate matter transports, estimated mercury fluxes from the English Channel to the North Sea were 1.8 and 2.3 t a-1 for dissolved and particulate mercury, respectively.