Phytoplankton biomass and composition as useful tools for assessing the impact of early anthropogenic pressure in the Western Mediterranean

In accordance with Article 1 (3) of Directive 2008/56/EC (Marine Strategy Framework Directive, MSFD), the collective pressure of human activities needs to be kept within levels compatible with the achievement of Good Environmental Status (GES), ensuring that the capacity of marine ecosystems to respond to human-induced changes is not compromised. Focusing on long-term time series of environmental and phytoplankton data acquired in Corsican coastal waters, we show how phytoplankton biomass and composition can be used to assess the impact of climate variation and early eutrophication processes. We identify some gaps in information required to implement the MSFD at a regional scale and we propose key directions to overcome them.