Cross-linking plankton indicators to better define GES of pelagic habitats - EcApRHA Deliverable WP1.4

The multimetric approach is a methodological tool which can be used to study a range of systems, including GES assessment of marine waters. Three indicators (PH1, PH2 and PH3) are currently being developed in the frame of the OSPAR convention for the pelagic habitat component. The three PH indicators provide information on different and complementary aspects of the plankton community that, only when considered altogether, provide a holistic vision of the ecosystem which is central to GES assessment. The present document aims at combining their information for the first time, following a multimetric approach. For this purpose, it was decided that the Plymouth Marine Laboratory L4 station would be the focus of this deliverable for the period 2000-2014.



Different results were obtained from PH1, PH2 and PH3 regarding dates characterized by atypical plankton community structures, stressing their complementarity. However, similar results were also found for some sampling dates, suggesting that the complementary information conveyed by the three PH indicators shows potential for generating a higher-level indicator.



This work has also evidenced a number of gaps and issues in the integration of the three PH indicators that we address with guidelines. In particular, efforts should be devoted to overcome technical difficulties in the integration the PH3 indicators, especially regarding differences in temporal resolution. Future development of the indicators could involve complementary techniques to classical methods to overcome taxonomic constraints. In the frame of this project, the access to data in certain format was identified also found problematic. Creating a central database of pre-formatted data managed by a group of experts could also benefit the regional calibration of the indicators for areas where appropriate data are available. Establishing a clear and easily accessible report which details all the monitoring guidelines concerning the metrics used for the OSPAR PH indicators could also be beneficial for homogenising the monitoring and inter-comparability of data among contracting parties in the goal of regional marine management.