Elementary composition of suspended particulate matter in the North Sea

The concentrations of the elements Al, Si, Ti, Fe, Mn, Ca, Mg, K, Cu, Zn, Cr, Pb, Ni, Cd, V and of particulate organic carbon (POC) were determined in 210 samples of suspended matter collected at 119 stations in the North Sea in January-February 1980. The distribution of these 15 elements and POC in the suspended matter in the North Sea was studied, as well as their relation with total suspended matter concentrations and salinity. The interrelationships between these elements were found to differ in different regions of the North Sea, which is related to the origin of the suspended material and the degree of mixing. A cluster analysis including all determined elements at all stations showed that the suspended matter in the North Sea consists of three clearly separated, specific types. One type was found in the northern part of the North Sea, the second in the southern part of the North Sea, while the third type was mainly observed in the Norwegian Channel, Skagerrak and eastern English Channel.The observed distributions are in agreement with what is known on the dispersal and deposition of suspended matter in the North Sea. Material from the southern North Sea hardly reaches the central and northern North Sea and the northern parts of the Norwegian Channel. The distribution of Mn is very strongly related to the accumulation of Mn in the top layers of finegrained bottom sediments and to the resuspension of Mn-enriched particles.