ESTUARINE SEDIMENT REMEDIATION - EFFECTS ON BENTHIC BIODIVERSITY

Estuaries have been used historically for the disposal of a range of e ffluents, and this has led to wide-scale sediment and water column con tamination. More recently, a number of national and international prog rammes have been implemented to improve estuarine water and sediment q uality. In order to predict the ecological consequences of improved en vironmental quality, there is a need to understand the processes under lying the response of the biota. This paper reviews evidence from moni toring programmes and field experiments in the Tyne estuary (NE Englan d) and the results of microcosm studies to assess the extent to which environmental remediation programmes have led to improvements in benth ic communities. It was found that the changes in the Tyne have been la rgely the result of lowered sediment organic matter concentrations. Ho wever, observations of effects of metals and rate of recruitment to az oic sediments provide useful data on the processes underlying recovery . These results are placed in the context of other studies of the resp onse of estuarine benthic communities to perturbations in order to pro vide a synthesis of the role of the various processes operating and th eir spatial and temporal scales. (C) 1997 Academic Press Limited.