Heavy metal content of mussels in the Western Scheldt estuary

Context of the study

Since 1987, the Eastern Scheldt estuary was blocked by dams (the DeltaWorks project) to create a barrier against flooding. Because of this blockade the Eastern Scheldt was turned from an estuary to a protected marine bay. Input of chemical contaminants from land decreased drastically, although heavy metals might still persist in the soils. The adjacent Western Scheldt drains through the most populated and industrial regions of Belgium, The Netherlands and France, making it one most polluted rivers of Europe and one of the major sources of heavy metals in the North Sea.

Content of the study

The study aims to compare the heavy metal contents of mussels in the Eastern Scheldt bay with those in the Western Scheldt estuary. This way they can asses whether heavy metal levels indeed have gone down in the Eastern Scheldt. The mussels were sampled in a land to sea gradient, which in the Western Scheldt coincided with a gradient of salinity and pollution.

Main results of the study

Heavy metal concentrations showed both in the Western Scheldt estuary as in the Eastern Scheldt bay a decreasing trend towards the sea.