Collaborative approach for the management of harbour-dredged sediment in the Bay of Seine (France)

Dredged material dumping is one of the most important human activities to be considered in coastal zone management. Searching for a new site for depositing the sediment dredged from the entrance of the navigation channel of Rouen harbour in the Seine estuary is complicated because of the combined natural heritage and anthropogenic constraints. This paper presents the intricate background and the collaborative efforts of the Seine estuary tripartite authority (National Government-Rouen Harbour-Scientific Committee) to initiate an ecosystem approach for managing waste. The selection of a future potential dumping area stems from a consideration of economic and logistic factors, both marine and environmental, as well as various natural and anthropogenic constraints in the complex ecosystem of the Seine estuary. It appears that a site with fine-to-medium clean sand situated offshore from the mouth of the Seine estuary would be a good candidate from the biological and economic points of view. Additional procedures on two experimental sites will be necessary before the French government can give a final decision to authorize the Rouen harbour to exploit this new deposit location.