Evaluation du risque d'introduction d'espèces indésirables par l'intermédiaire des eaux de ballast des navires

The discharge of ship's ballast waters in coastal areas is considered as a vector for exotic species introduction, a threat for the local ecosystems or even the mariculture activities. The most worrying are the toxic phytoplanktonc. Unwanted effect presently documented in the world were rewieved. The risk analysis applied to this problem is discussed. Regulations and research programs about ballast waters in several countries were also overviewed. A ship's arrivai study in Charente-Maritime (France) let appear a large percentage of them were coming from areas where the occurrence of toxic phytoplankton blooms are common. Known technical solutions, populations and guidelines are recorded. A non exhaustive list of toxic phytoplankton blooms occurences in several countries for the last twenty years is given.