Can we define a good pelagic habitat that leads us to tangible management targets for the pelagic ecosystem?
The pelagic system is home to microbes, plankton, nekton, sea mammals, birds, and reptiles. It also drives a large proportion of the productivity of the ocean and seas. Following on from the recent ICES symposium on marine ecosystem acoustics, the review of the MSFD descriptors, the ICES and NOAA supported WKFOOWI (foodweb indicators), and the current indicator developments by OSPAR and HELCOM, there is still the outstanding question: What do we mean by good environmental status for the pelagic ecosystem?
This question is confounded by the suggestion to use surveillance indicators for many of the metrics collected for the pelagic system (e.g. plankton abundance and composition time-series) and the idea that pelagic fish can exert formidable pressure on the plankton standing stock (as some have proposed for the Norwegian Sea). Is it possible to set anything but higher order objectives (as set in legislation) for this ecosystem? Are operational objectives (linked to management action) tangible? How can monitoring take place and status be determined with respect to these operational objectives?