Monitoring sediment bound cadmium in sømme bay, Hafrsfjord, Norway

Abstract

Cadmium is considered to be a very toxic heavy metal for organisms at all levels of organisation. Therefore, careful analysis is made in Sømme bay, Hafrsfjord as this area is a very important marine wetland habitat, particularly for migrating birds. It was found that cadmium flows with the treated drainage water from the airport water treatment plant and we measured a mean concentration of 2.72 μg/g dryweight which has important effect on animal life like oxygen depth depletion, development of harmful algae and species modifications. Sedimented cadmium flows through sediment to the deepest areas of the fjord. We found out that the deep water sediments contain 10-84 μg/g cadmium, values which make life impossible in any form. There is a strong correlation between cadmium and organic content. We recommend that special attention is attributed to cadmium containing drainage water, waste dumping sites and runoff of agricultural pesticides into the fjord's ecosystem.