Dynamic Coastal-Shelf Seascapes to Support Marine Policies Using Operational Coastal Oceanography: The French Example

In the context of maritime spatial planning and the implementation of spatialized Good Environmental Status indicators in the Marine Strategy Framework Directive (MSFD), the definition of a mosaic composed of coherent and standardised spatial units is necessary. We propose here a characterization of seascapes in time and space within the specific framework of the MSFD in the English Channel and the Bay of Biscay areas. A spatio-temporal classification of coastal-shelf water masses is carried out using twelve essential oceanographic and derived variables from operational coastal oceanography using the HYCOM model. Partitioning is computed using a multivariate hybrid two-step clustering process defining a time series of categorical maps representing hydrographical patch classes. Main patch occurrence is analyzed to understand their spatio-temporal dynamics and their oceanographic characteristics. Finally, patch classes are combined with MSFD marine sub-region delimitations to build seascapes, including ecosystem approach management and marine policy considerations.