Common lists of elements for the biodiversity assessments
The revision of the SEC 2011/1255 Table 3 of functional groups concluded in the following table (Table 1), where the MSFD terminology was also revised. There is no change in the biodiversity components (Birds, Mammals, Reptiles, Fish and Cephalopods) of the highly mobile and dispersed species. Each one includes revised biodiversity groups (species/functional groups), that should be the main assessment unit for the D1 reporting, through representative biodiversity elements (species). 

Representative species (biodiversity elements) within each group should be accounted for in sufficient number in order to ensure a robust representativeness of the Biological Diversity (D1) GES assessment, and for this a de minimum approach was discussed in terms of adequate numbers of species to consider within each group. The selection of species within those proposed groups (Table 1: Biodiversity elements) should respect the list of criteria specified in paragraph 2.3. Additionally, it is suggested to consider all species for which data/assessments are already available under the Habitats & Birds Directives (further discussed in a following section) and to be in line with latest changes/agreements with the RSCs.
Table 1. Biodiversity Components and elements (highly mobile species) to be considered within D1 assessment (modified from Table 3 of the SEC 2011/1255) as minimum requirement.

Biodiversity Components

Biodiversity groups (assessment units): Species group


1.       Grazing feeders

2.       Wading feeders

3.       Surface feeders

4.       Pelagic feeders

5.       Benthic feeders


1.       Small toothed cetacean

2.       Deep divers toothed cetacean

3.       Baleen whales

4.       Seals


1.       Turtles


1.       Coastal


2.       Pelagic fish &  elasmobranchs

3.       Demersal fish & elasmobranchs

4.       Demersal deep-sea fish & elasmobranchs


1.       Coastal/shelf pelagic cephalopods

2.       Deep-sea pelagic cephalopods

Note: D1 Indicators and criteria (at species level) have to be assessed for each individual species selected; and then all species assessments have to be aggregated (cf. 5.1) under each of the species groups (assessment units) as a minimum requirement. Species assessed under the Habitat (92/43/CEE) and Bird (2009/147/CE) Directives can be used for the species to consider for the MSFD D1 assessment, but other species can be used/added, to fulfil selection criteria (cf. 3.2) and representativeness of each species groups. For the fish groups, commercial species assessed under CFP can be used, but have to be complemented by other species, to also reflect primary (de)selection criteria (cf. 2.3). Invertebrates, algae and other benthic and pelagic (less mobile) organisms are assessed at the community level, in habitats. Any relevant species not considered as minimum requirements and not covered by the above grouping, but which are considered important (sub-regionally) to be accounted for in D1 assessment should be included by the Member States/Regional Sea Conventions e.g. some Diadromous Fish at certain stages of their life cycle. The expert group concluded that more effort is needed to further define and clarify fish groups. The option of having sub-groups seemed helpful, without being able to end up with a final proposal. Coastal has to be specified (taking into account other legislations – WFD, CFP, etc.). Indicatively, pelagic species can constitute two sub-groups: i) Small pelagics (e.g. sprat, herring, mackerel) and ii) Large pelagics (e.g. blue shark, tuna, swordfish). The expert group also proposed to group teleosts and elasmobranchs in a single category, in contrary to the current grouping in the CSWD (2011), to enhance the statistical inference and facilitate the GES definition at that level.
Review of the 'Habitat Types' entries in Table 1 in the MSFD Annex III in relation to D1 requirements:
The EUNIS classification system is recommended as the basic common EU standard for MSFD habitat assessments. The expert group revised Table 7 (SEC 2011/1255) on the predominant habitat types concluding to Table 2 for the proposed updated list of biodiversity components and groups for habitats to be used for MSFD assessment (MSFD terminology is also updated accordingly). Table 3 illustrates the links across habitats groups (to be reported) and EUNIS level 2 typology. The group also concluded on the following:
Table 2. Revised list of biodiversity components and groups (former predominant) for habitats, as minimum requirement for MSFD reporting.

Biodiversity Components

Biodiversity habitat groups

Benthic (former seabed) habitats



Littoral rock and biogenic reef

Littoral sediment

Infralittoral rock and biogenic reef

Infralittoral coarse sediment

Infralittoral sand

Infralittoral mud

Infralittoral mixed sediment

Circalittoral rock and biogenic reef

Circalittoral coarse sediment

Circalittoral sand

Circalittoral mud

Circalittoral mixed sediment

Upper bathyal rock and biogenic reef

Upper bathyal sediment

Lower bathyal rock and biogenic reef

Lower bathyal sediment

Abyssal rock and biogenic reef

Abyssal sediment

Pelagic (former water column) habitats




Note: D1 Indicators and criteria (at habitat level) of the MSFD D1 assessment have to be assessed for each representative habitat selected (EUNIS level 4/5); and then all representative habitat assessments have to be aggregated (cf. 5.1) under each of the habitat groups (assessment units) as a minimum requirement. Habitats assessed under the Habitat (92/43/CE) and Water Framework (2000/60/CE) Directives can be used for the representative habitats to consider for the MSFD D1 assessment, but other habitats have to be used/added, to fulfil selection criteria (cf. 3.2) and representativeness of each habitat group.
Table 3. Correspondence between biodiversity habitats groups (minimum requirements) and proposed EUNIS 2015 typology. Red lines delineate revised benthic habitats groups from Table 2 (minimum requirement for MSFD reporting) and their allocation to the new EUNIS classification level 2 (2015 EEA proposal); Black lines delineate further optional subdivision of these habitats groups, reflecting previously used classification in EUNIS, and (sub)regional specificities.








EUNIS Level 2


Biogenic habitat (flora/ fauna)





e.g. non-oxygen-based habitats








































* Includes soft rock - marls, clays-, artificial hard substrata
The group proposed that:
  • the MSFD biodiversity habitats groups are aligned with the proposed 2015 EUNIS classification (level 2);
  • for MSFD reporting, some habitats groups are groupings of the new 2015 EUNIS level 2 classes, according to the red lines in table 3 (minimum reporting requirements).
Member States may optionally choose to subdivide these red categories according to the thick black lines (Table 3), particularly to ensure that specific pressure/impacts on these finer units are not unduly masked by the higher aggregation). This could be regionally specific, notably for the upper and lower circalittoral extents, or for those countries with larger sea areas. Consequently, further alignment are needed between MSFD minimum requirement level for habitats, and EUNIS corresponding level, since the distinction between upper and lower circalittoral zones is now defined at level 4 in the new EUNIS classification (EEA 2015 proposal). The upper and lower bathyal zone split is retained because the lower bathyal and abyssal zones are typically subject to lower intensity of pressures, and fewer types of pressure, notably those due to fisheries. This split for bathyal habitats (benthic and pelagic) can also be related to specific representative communities, also indirectly linked with mammal's use of these habitats (e.g. deep diver cetaceans).
The expert group also concluded on the fact that a set of representative habitats (habitats selected according to the 2.3 criteria, most probably at EUNIS level 4/5 or drawn from special/listed habitats) will have to be assessed to represent habitats groups (EUNIS level 2). The exact aggregation process (method and rules) from the representative habitats (EUNIs level 4/5) to the habitat group (EUNIS level 2) needs to be further developed (work in progress as regional processes in RSCs), but the general principle is illustrated in Figure 1. Further work is also needed to clarify whether the representative habitats will be aggregated inclusively into a habitat group (circallittoral sand in Fig. 1), or primarily to:
  • special habitats defined by HD (H1 in Fig. 1)
  • special habitats defined by the RSCs (H2 in Fig. 1) and
  • representative habitats of MSFD interest
and secondary to the habitat group level.
Selection/deselection criteria for the inclusion of species and habitats in a group:
Proposed criteria for the selection of species and habitats to be assigned to the new species and habitats groups. The first set of criteria are scientific and based on ecological relevance. The second set of criteria take into account practicalities such as monitoring and technical feasibility.
Primary scientific criteria – ecological relevance for D1
  • Representatives of an ecosystem component (species or habitat group): i.e. relevance for assessment of state/impact and/or relevance for assessment of pressure/activity.
  • Species/ habitats vulnerable (=exposed) to a pressure, to which it is sensitive;
  • Key functional role of species/habitats (e.g. high or specific biodiversity, productivity, trophic link, specific resource or service, etc.)
  • Sufficiently present across (sub)region: high proportion (extent or occurrence) of species/ habitat occurs within the specific region or sub-region (i.e. 'commonness')
  • Present in sufficient numbers: to be able to construct the indicator
Secondary practical criteria: Practical consideration, but which cannot substitute to primary requirements
  • Monitoring/technical feasibility
  • Monitoring costs
  • Reliable time series
D1 general implementation scheme
Figure 2. An example of how the assessment of a species group could be undertaken. For each one all releveant criteria and indicators have been applied (light red rectungulars) and aggregated accordingly.

Figure 3. Assessment of an habitat group from the aggregation of representative habitats (EUNIS level 4/5) selected by the criteria in paragraph 2.3. For each one, all relevant criteria and indicators have been applied (light red rectungulars) and aggregated accordingly. Pressure Descriptors' assessments feed the habitat assessments in terms of evaluating the anthropogenic impacts into the habitat physical aspects.