The Distribution of Selected Trace Metals in United Kingdom Shelf Waters and the North Atlantic

Abstract

The distribution of dissolved and suspended particulate Cd, Cu, Mn, Ni, and Zn was surveyed in the water of the North Atlantic and adjacent European shelf seas. The exercise was conducted by the Lowestoft Fisheries Laboratory and was part of a broad program coordinated by the International Council for the Exploration of the Sea (ICES) Working Groups concerned with pollution baseline and monitoring studies. The distribution of dissolved metals was enriched in coastal waters up to an order of magnitude compared with the offshore shelf seas. Both anthropogenic and natural sources of metal were considered in relation to the elevated inshore values. The suspended particulate phase of trace metals present in coastal and shelf waters was often a significant proportion (between 5 and 70%) of the total metal present. Oceanic values of dissolved metal were comparable with concentrations measured in offshore shelf seas. Deep vertical profiles of trace metals resembled the distribution of nutrient salts, thus indicating biological mobilization. The validity of all data was discussed in relation to current sampling and analytical techniques. The degree of sampling and analytical sophistication employed must relate to the basic requirements of the exercise.