Activity 4: 214 Streamlining Descriptor’s D1 selected criteria regarding mammal’s species groups (small toothed cetaceans, deep diving toothed cetaceans and baleen whales) towards coordinated monitoring and assessment in the Mediterranean.

Over the past years, important progresses have been made in the Mediterranean Sea regarding cetaceans’ monitoring, as part of the EU MSFD implementation and other national research activities such as the national monitoring programs developed and implemented in parallel with the ACCOBAMS Survey Initiative (ASI) for Mediterranean countries. 

In 2018 and 2019, ASI led for the first time to the successful implementation of cetacean large-scale surveys that covered the entire Mediterranean Sea. The results of this effort have allowed to obtain the first baseline on abundance, density and distribution of cetacean species at the regional level. However, there is still a strong heterogeneity among EU Mediterranean countries in the implementation of the MSFD. Such disparity at national levels may hinder the transboundary collaboration needed for evaluating further and properly the GES. Thus, it is of foremost importance to establish coherent monitoring strategies for highly mobile species that would contribute to a robust science-based evaluation of GES at temporal and spatial scale in the Mediterranean. 

Regional and sub-regional large-scale aerial surveys for cetacean abundance estimation may provide a successful example of transboundary collaboration. However, if they are not periodically repeated because of lack of means or if they are not carried out at the appropriate scale, they may fail to capture the temporal and geographical variability of the species distribution which is extremely dynamic for the highly mobile species in times of climate change. On the other hand, long-term monitoring studies conducted on localised areas or regional/sub-regional monitoring efforts conducted from other platforms (such as the ferry-based and boat-based surveys) may produce relevant knowledge about the temporal variability which affects the distribution and abundance of these species. Lastly, assessing the distributional range and defining the suitable habitats of the species is another challenge to be addressed for consistent monitoring of cetacean species. 

Activity 4 will focus on finding the way to integrate this information deriving from these different types of studies. Relying on ACCOBAMS mandate to promote regional cooperation, this activity will support the establishment of a regional network/working group of experts/managers from the different EU Mediterranean countries aimed at strengthening the coordination for monitoring cetacean MSFD related criteria, including the definition of proposals for regionally harmonized monitoring strategy and thresholds values. It will also support some analytical activities related to data gathering, through detailed assessment of monitoring scales and methods, including a pilot on the potential interest of telemetry in the MSFD context. 

The specific objectives of Activity 4 are: 

O4.1: Streamline the monitoring of D1 cetacean related criteria in the Mediterranean Sea, in particular by supporting regional coordination between EU countries and cooperation with non-EU countries;

O4.2: Capitalize the available information on the species groups (small toothed cetaceans, deep diving toothed cetaceans and baleen whales) on the basis of the information, already acquired by EU countries throughout the national monitoring programmes;

O4.3: In accordance with the 2017 Commission Decision on Good Environmental Status (Commission Decision 2017/848), this activity will in particular allow to:

– further develop and operationalize cetaceans related criteria, 

– support coordinated assessment of Mediterranean cetacean species, including the definition of D1C1, D1C2, D1C4 and D1C5 threshold values,

– assess and improve the consistency of the determination of GES related to cetacean Species.