INTERTIDAL PLACEMENT OF DREDGED MATERIAL: A BIOLOGICAL PERSPECTIVE

In the UK, the use of fine-grained dredged material for intertidal habitat creation is currently being viewed as an environmentally beneficial method of disposing of material which has traditionally been regarded as waste. At present, uncertainties over the physical and biological consequences of this activity partly limits its scope to small-scale field trials. This paper presents the research approach being undertaken at the Centre for Environment, Fisheries and Aquaculture Science (CEFAS) to improve our understanding of the invertebrate recovery mechanisms and to what extent they are affected by dredged material properties (organic content, particle size). This is being achieved via a combination of site-specific and non site-specific research. The site-specific approach involves investigating the recovery of a number of representative ‘beneficial use’ schemes on the Essex and Suffolk coasts, UK. The resulting data have operational value but, inevitably, the schemes vary in a number of ‘uncontrollable’ respects; field manipulation experiments comprising the non site-specific approach addresses this. The preliminary conclusions from these approaches are presented.