Assessment of the response of the zoobenthic community to coastal nourishment. Sampling in spring & autumn after completion of nourishment. Sample & data analysis. The main objective of the RIACON project is to evaluate the risk of shoreface nourishment and subaqueous sand extraction for the marine (zoo)benthic community and its consumers higher up in the foodweb. The risk will be evaluated through studies at the three sites of the MAST-II project NOURTEC (Innovative Nourishment Techniques Evaluation), viz. The Netherlands, Federal Republic of Germany, and Denmark as well as at two other sites, viz. in Belgium (De Haan) and Spain (coast of Catalunya). The project objectives will be achieved by: - studying the response of the (zoo)benthic community (decrease and recovery of species abundance and biomass) at five sites of shoreface nourishment along the coasts of the North Sea (Denmark, Germany, Netherlands, Belgium) and the Mediterranean (Spain). Reference sites will be included in the study to facilitate drawing of meaningful conclusions. - studying the response of the (zoo)benthic community (decrease and recovery of species abundance and biomass) at three sites of sand extraction (borrow sites) used for shoreface/beach nourishment (Netherlands, Denmark, Spain). In Spain special attention will be given to the Posidollia Community. Inclusion of reference areas will be realised as much as possible. - evaluating the risks for consumers of the (zoo)benthos higher up in the food chain and/or other inhabitants of the coastal habitat where nourishment takes place. The response of the (zoo)benthic community will be measured in terms of numerical density and biomass of species, age and/or size composition of species, and quantitative and qualitative aspects of composition of the community. Parameters or indices that are best appropriate to describe changes in community composition will be defined at a first workshop. The risks for consumers of the (zoo)benthos higher up in the food chain will be evaluated by considering the effect of loss of specific prey species, of loss of specific prey sizes, of loss of specific benthic community characteristics, etc.