Despite its success in the Atlantic Area over the last twenty years, the shellfish industry today is still threatened by the presence, on the coasts, of a micro-organism (a phytoplankton) which is harmless to shellfish but toxic for humans – Dinophysis – and which leads to the closure of aquaculture sites for long and frequent periods. Faced with the disadvantages and shortcomings of current techniques for sampling, study and forecasting of Dinophysis attacks, the NEMEDA project is intended to create and develop a network of experts who are making a profound study of its life-cycle, the process by means of which it contaminates shellfish and the current harvesting procedures. Achievements: ✔ Positive contribution to the knowledge of species of Dinophysis: State of the art compilation for dissemination. Joint field studies in three main areas where Dinophysis is present (in France, Spain and Ireland). Study of the populations of micro-organisms encountered in the different layers of surface waters identified. An innovative aspect of the project consisted in applying high technology observation methods developed by Ifremer, and made available to the other members of the partnership. Measurements by fluorescent microscopy; measurements of the growth rate of the populations; exploration of new development characteristics likely to influence management methods for coastal areas. Identification of other species of harmful phytoplanktons (Karenia; Pseudo-nitzschia) detected in the zones being studied. ✔ Identification of new funding sources and preparation of future research projects: A new grant was raised which made it possible to continue the research work into to other species of harmful planktons until 2008. ✔ Dissemination of the results to players involved in the management of coastal waters and end users: the coastal waters management agencies (Marine Institute and INIAP) integrated in the project partnership, have organised information workshops for the aquaculture workers in their region on the results of the research conducted during the project. ✔ International dissemination of the results: 12 presentations in two international conferences in front of more than 1000 professionals. The partners participated in initiatives such as EUROHAB or GEOHAB (UNESCO project on "Harmful Algal Blooms"), ICES and IPHAB.