A process-driven sedimentary habitat modelling approach, explaining seafloor integrity and biodiversity assessment within the European Marine Strategy Framework Directive

The Marine Strategy Framework Directive (MSFD) seeks to achieve good environmental status, by 2020, for European seas. This study analyses the applicability of a process-driven benthic sedimentary habitat model, to be used in the implementation of the MSFD in relation to biodiversity and seafloor integrity descriptors for sedimentary habitats. Our approach maps the major environmental factors influencing soft-bottom macrobenthic community structure and the life-history traits of species. Among the 16 environmental variables considered, a combination of water depth, mean grain size, a wave-induced sediment resuspension index and annual bottom maximum temperature, are the most significant factors explaining the variability in the structure of benthic communities in the study area. These variables are classified into those representing the 'Disturbance' and 'Scope for Growth' components of the environment. It was observed that the habitat classes defined in the process-driven model reflected different structural and functional characteristics of the benthos. Moreover, benthic community structure anomalies due to human pressures could also be detected within the model produced. Thus, the final process-driven habitat map can be considered as being highly useful for seafloor integrity and biodiversity assessment, within the European MSFD as well as for conservation, environmental status assessment and managing human activities, especially within the marine spatial planning process.