Understanding benthic habitats’ sensitivity to anthropogenic pressures is central to the effective management of the marine environment. Sensitivity assessments help to:

  • identify those pressures that might impede the achievement of good environmental status (or favourable conservation status) for habitats and species,
  • assess habitats and species’ vulnerability or risk of being impacted by human activities,
  • identify and prioritise appropriate management measures that are consistent at a local, regional and national scale.

This programme has begun with the assessment of marine habitats’ sensitivity to anthropogenic pressures. The sensitivity of mobile marine species (in particular, Habitats Directive Annex II species) will be evaluated in the near future.

Habitat benthique de Méditerranée © O. Bianchimani – Septentrion Environnement & Habitat benthique de Manche © W. Thomas – Station Biologique de Roscoff

Methodology for the assessment of marine habitats’ sensitivity

The French Ministry of Environment asked the MNHN-SPN to develop a scientific methodology to assess the sensitivity of French (mainland) benthic habitats to anthropogenic pressures, drawing on expertise from the wider scientific community.

Habitat sensitivity is defined as the combination of its ability to tolerate an external pressure without significantly changing its biotic and abiotic characteristics (resistance) and the time needed to recover, once the pressure in question has been alleviated (resilience).

Sensitivity assessment involves the following steps:

  • Identify the key biotic and abiotic elements affecting the habitat sensitivity;
  • Assess the habitat’s resistance to the pressure in question;
  • Assess the habitat’s resilience to the pressure in question;
  • Combine resistance and resilience scores to generate an overall sensitivity score.

Click here for the diagram presenting the stages of sensitivity assessment

The terminology, habitat and pressure units, methodological framework for marine habitat sensitivity evaluation as well as guidance on how to use the resulting evaluations are presented in the following methodological report.

This methodology was developed to produce standardised results at a national level and to be consistent (insofar as possible) with other equivalent European methodologies, in order to support risk/vulnerability assessments at a national and international scale (under the HD, MSFD, OSPAR, etc.)

This habitat sensitivity data will support the management of human activities in the marine environment.

Click here for the diagram presenting guidance on the use of sensitivity data

Biocénose des algues infralittorales de Méditerranée © N. Michez

French benthic habitats’ sensitivity

Assessments of French benthic habitats’ sensitivity to physical pressures are presented as matrices.

Each matrix presents, for each habitat/pressure combination:

  • A resistance score and its confidence index
  • A resilience score and its confidence index
  • A sensitivity score and its confidence index
  • The evidence base for these assessments.

A first set of assessments were conducted using habitats units defined in the French Mediterranean benthic habitat classification. These assessments are presented in a report as well as in separate Excel spreadsheets.

To support implementation of management measures, particularly within Natura 2000 sites, sensitivity matrices of Habitat Directive Annex I sub-types of the French Mediterranean (of the French Mediterranean) are also provided.

These matrices are based on the French Mediterranean benthic habitat classification sensitivity scores, aggregated according to the recommendations in the methodological report. Sensitivity matrices of Habitats Directive Annex I sub-types for French Atlantic, English Channel and North Sea habitats units to physical pressures are available as Annexes to a report as well as in separate Excel spreadsheets (in French).

The sensitivity of French benthic habitats to other physical pressures (e. g. underwater noise, changes in salinity, changes in temperature, etc.) and to chemical and biological pressures will be published at a later stage.