LAUSR

Abstract As part of its commitment to the EU Marine Strategy Framework Directive (MSFD) OSPAR has developed three plankton indicators of Good Environmental Status (GES) for pelagic habitats in the Northeast Atlantic. In coming years, implementation of the MSFD will extend into the Arctic, requiring the application of pelagic habitat indicators in the region. Because plankton communities and monitoring effort are spatially variable, applicability to the Arctic of existing indicators must be assessed. A meta-analysis is applied to the Northeast Atlantic pelagic habitat indicators to establish their ecological applicability and relevance to Arctic marine ecosystems and their implementability using existing national monitoring effort. To identify gaps and potential improvements in the OSPAR indicators, two gap analyses were conducted. The first considered the Northeast Atlantic OSPAR-adopted indicators and existing plankton indicators currently employed by Arctic nations. The second assessed the minimum data attributes required to implement existing OSPAR indicators compared to existing national plankton monitoring effort by OSPAR Arctic contracting parties. Existing Northeast Atlantic pelagic habitat indicators were found to be ecologically applicable to the Arctic, primarily due to flexibility of the plankton lifeforms and biodiversity indices indicators, that allow selection of regionally relevant lifeform pairs or species for assessment. However, current national monitoring programmes were found insufficient to support their implementation. Additional regionally-specific indicators, such as for sympagic phytoplankton and sea-ice biota, are worthy of consideration. Budgetary constraints and a lack of year-round sampling and long-term datasets were found to be key limitations in the implementation of plankton indicators for establishing GES.