Publication providing elaborated guidance how to assess sea-floor integrity under the MSFD

doi:10.2760/8315684

Most EU countries have in the meanwhile reported on the marine benthic habitat quality status under the MSFD, taking into consideration the guidance on Article 8 assessment* in development and discussed in the Technical Group Seabed**. Although the assessment guidance with regards to sea-floor integrity will continue to be developed the coming years, now an interim overview has been published. It provides the current status of guidance with more elaborated information, examples and ways of handling data, use of indicators and the first agreed threshold values.

RAICEVICH, S., KORPINEN, S., SCHROEDER, A., WIJNHOVEN, S., DINESEN, G.E. et al., Assessment of sea-floor integrity under the EU Marine Strategy Framework Directive – Supplementary information to the Article 8 assessment guidance, ALONSO ALLER, E. and VIGHI, M. (editors), Publications Office of the European Union, Luxembourg, 2025, https://data.europa.eu/doi/10.2760/8315684, JRC142314.

The report provides supplementary information to the Article 8 assessment guidance document (European Commission, 2022) where:

  • the physical pressures impacting the sea-floor and benthic habitats are defined,
  • human activities causing such pressures are discussed,
  • elements to be assessed are identified,
  • assessment scales and marine reporting units are proposed,
  • inter-relations with other MSFD criteria and other policies are identified and integration with them suggested,
  • the agreed threshold values are presented, and
  • approaches to address uncertainty are discussed.

TG Seabed has agreed on the general principles of the assessment of sea-floor and benthic habitats, such as pressure definitions, definition of adverse effects and necessary thresholds indicating good status. With these general principles, the coherence of the Member States assessments under Descriptor 6 will improve, and it is anticipated that many details will likely become clearer once good practices have accumulated from the upcoming assessments.

This report has been updated to integrate the latest developments under TG Seabed until December 2023, and thus includes references to the D6C4 and D6C5 threshold values proposed by TG Seabed and adopted by MSCG on 15 March 2023 and endorsed by Marine Directors on 4 June 2023.

* The assessment of the sea-floor and benthic habitats of Europe’s seas is a requirement of the EU Marine Strategy Framework Directive (MSFD) under the qualitative descriptor 6 (“Sea-floor integrity is at a level that ensures that the structure and functions of the ecosystems are safeguarded and benthic ecosystems, in particular, are not adversely affected”). Article 8 of the MSFD requires this assessment, while Commission Decision 848/2017 lays down the criteria and methodological standards for such an assessment. The guidance document #19 for the MSFD implementation provides an overview of the assessments under Article 8 for all the qualitative descriptors, while this report aims to give a more elaborated guidance for Descriptor 6.

**TG Seabed is the ‘technical group on seabed habitats and sea-floor integrity’ established by the Member States and the European Commission under the MSFD Common Implementation Strategy.

All BISI related information gathered on one site

Westerschelde intertidal zone

The BISI protocol for generic application (BISI v2) is available now. The Benthic Indicator Species Index (BISI) is specifically developed for quality status evaluation and evaluation of quality developments of benthic habitats. Compared to v1, BISIs (area specific indicator species lists with reference occurrences for comparison) are in v2 constructed in a standardized way at the level of ecotopes (or broad habitat types) which allows application in similar habitat within the same region. From these BISIs at ecotope level, area specific indices can be constructed surface area ratio based.

Specific assessment tools are developed and made available for:

  • Application in soft sediment habitats of OSPAR region II (Greater North Sea region) distinguishing 6 broad habitat types and make use of approximately 0.1 m2 grab or (box)core monitoring data.
  • Application for marine Habitat Directive (HD) habitat types of the Dutch ‘Delta-waters’, the Wadden Sea and the coastal zone of the North Sea, making use of benthos data from two categories of sampling techniques (core – and benthic dredge related samples).
  • Application in distinguished areas of the Dutch North Sea with regards to the MSFD, the HD and evaluation of effectiveness of management measures, making use of benthos data from core – and benthic dredge related samples in (most) soft sediment areas, and the combination of video and grab sampling in areas with gravel and boulders.

Tools are available for direct application in similar situations (habitats x monitoring techniques), or new BISIs can be constructed according to the protocol for other types of habitats, geographical regions and/or monitoring specificities.

We are very interested in the results and experiences from testing or application of existing assessment tools or new constructed BISIs specific for other situations based on your own monitoring data. Therefore all BISI related documents (including with regards to earlier versions) and assessment tools are now gathered on one site: http://ecoauthor.net/bisi/. You will stay informed on new developments, applications and/or results via the BISI site. Please contact us if we can be of help or to share your findings.

The focus of current international quality status assessments (e.g. MSFD – and OSPAR assessments) with regards to seafloor integrity is predominantly on large-scale assessment of expected impact from dominant pressures taking sensitivity of habitats into account. It is however of importance to verify the quality status with benthic observations, which can be related to specific impacts and habitat changes. Herewith key processes and management options can be identified or evaluated. The BISI could potentially fill in this gap.

Developing the Benthos Indicator for the Dutch North Sea

At present Ecoauthor is working on the development of the National Benthos Indicator for evaluation of the Dutch North Sea for the Marine Strategy Framework Directive (MSFD) in cooperation with Wageningen Marine Research. designing-a-national-benthos-indicatorThe challenge is to develop a transparant indicator that will be used for various evaluations and reportings (e.g. MSFD, Habitat Directive, evaluation of Nature 2000 management and evaluation of effectivity of taken measures) that can act on the various spatial and temporal scales involved and will be indicative for causes of potentially observed changes as well. Yesterday we had some good discussions and valuable information exchange during an expert workshop as organized by the Ministry of Economic Affairs (EZ) and the Ministry of Infrastucture and the Environment (I&M) for which I like to thank all participants and the organizers.

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