Baseline levels and natural variability of elements in three seaweed species from West Greenland

Abstract

Element levels in three seaweed species ( Fucus vesiculosus, F. distichus and Ascophyllum nodosum) from different sampling sites in a West Greenland fjord system were determined during a three year period. The elements studied were Cd, Cu, Pb, Zn, Na, Ca, Sc, Cr, Fe, Co, As, Br, Rb, Sr, Cs and Ce. The variability of element concentrations showed a complicated pattern. Differences between both species and localities were found for most elements. Species differences were found to depend on the locality. In most cases where differences between seaweed species were found, concentrations were lower in A. nodosum than in F. vesiculosus which in turn were lower than in F. distichus. At the outer part of the fjord system concentrations of Na, Br and Cd were considerably higher than in the inner part while concentrations of Ca, Fe, Co, Ce, Sr, Sc and Cu were lower. Pb and Zn concentrations show no consistent geographical pattern. The results from a principal component analysis were difficult to interpret. The possible underlying factors controlling the variability of element concentrations are poorly understood. The influence of seawater on the fjord system and variations in run-off from rivers may account for a significant part of the variability seen for many elements. The concentrations of most of the elements, especially the heavy metals, were relatively low compared to other areas in Europe and North America.