The International Council for the Exploration of the Sea (ICES) has reviewed three descriptors of Good Environmental Status (GES) of the European Union's Marine Strategy Framework Directive (MSFD). The review suggests revisions to the criteria of the descriptors, highlighting the need for the MSFD to consider how humans impact the functioning of the ecosystem. It also strengthens understanding of how to assess ecosystem health across many different habitats, and provides a roadmap for further research in the area.
The European Commission (EC) asked ICES to review the descriptors of commercial fish and shellfish (descriptor 3), foodwebs (descriptor 4), and seafloor integrity (descriptor 6). The review process was iterative and engaged with participants from all over Europe through workshops, consultations, and peer review.
For descriptor 3, ICES recommends combining considerations about the impacts of fishing mortality on biomass of stocks and the size of individual fish. It also highlights that the selectivity of the fisheries (the way the fisheries take certain ages or size of fish) needs to be considered within the MSFD, and proposes ways for this to be built into the regulation.
Foodwebs are by their nature complex and variable, thus detecting human impacts can be difficult and predicting any response of foodwebs to management measures is complicated. ICES recommends the MSFD emphasize two important properties of foodwebs; their structure and function. By considering these properties the short- and long- term health of foodwebs can be ensured. ICES also proposes methods for assessing foodwebs, and recommends regional approaches to monitoring the structure and function of selected trophic guilds.
In regards to seafloor integrity, ICES recommends that more emphasis is given to the services provided by and the functioning of the seafloor. It also highlights that the MSFD should consider all damage to the seafloor, not just "physical damage" as is now stated in the regulation. It is likely that existing national monitoring programmes can be adapted to assess these properties. ICES suggests ways to work with is partner organizations, aiming at cross-regional comparability, and will further discuss this at a Council Working Group meeting next month.