GUIDING PRINCIPLES FOR REVISING THE MARINE COMPONENT OF THE
EUNIS HABITATS CLASSIFICATION
By Douglas Evans, European Topic Center for Biological Diversity
The marine component of the EUNIS habitats classification has not been revised since 2004
except for the addition of some Black Sea habitats and some minor changes to habitat
descriptions. Since 2004 much new data has become available, particularly through EU
funded projects such as Balance, MESH, EUSeaMap and MeshAtlantic, together with
experience of using the classification. The experience gained using the EUNIS classification
around European regions has raised demands for a revision; see as examples some of the
aspects outlined in Galparsoro et al (2012) based on an expert meeting held in San Sebastian,
Spain, in April 2012.
Therefore the European Environment Agency (EEA) together with its European Topic Centre
on Biological Diversity (ETC/BD) agreed to revisit the marine component of the EUNIS
habitats classification as the first part of an overall review of the classification. The first stage
of this process was a workshop held at the EEA 28 & 29 November 2014 in Copenhagen,
which aimed to agree the general principles on which the revision would be based. This
document is based on the discussions at the Copenhagen workshop. The meeting
included invited experts chosen to include experience from the major seabed mapping
projects and from all European seas, together with representatives from the European
Commission (DG Environment), EEA and the ETC/BD. Unfortunately, representatives from
the Arctic and Black Sea were not able to attend. A list of participants is given as an
appendix.
Prior to the workshop David Connor (DG Environment) prepared a background paper which
made a number of proposals, largely based on the outcomes of the San Sebastian meeting
(Galparsoro et al., 2012). The workshop focused on revising the structure of the marine
section of the EUNIS habitats classification and concentrated on the upper three levels.
Further work is still required to define appropriate level 4 categories and consider
further some of the level 3 categories for which there was not enough time to finalise
definitions.
Defining levels
EUNIS is a hierarchical classification using 7 levels. In the current classification these levels
do not have names or unambiguous definitions. In the marine section the first levels are
mostly defined by abiotic factors with little biology before level 4. It was agreed that
definitions of each level would both be helpful for users and help structure the revision by
ensuring that the units in each level were comparable. Table 1 summarises the proposed
definitions and names for the revised classification. These names have been revised from the
current version of the classification in order to be more intuitive and avoid using words such
as ‘habitat’ which can have several meanings. It was acknowledged that the term biotope may
have different meanings in other European languages (notably French). No consensus was
reached on alternative names for the ‘Biotope’ and Sub-biotope’ levels so the original names
were kept, but more appropriate names may be found after further consideration.
Table 1: Proposed definitions for the revised marine component of the EUNIS habitats
classification.
Level
Name
Level 1
Realm
Level 2
Level 3
Definition
Contains a single class: Marine. Equivalent This is
equivalent to the Terrestrial and Freshwater realms.
Biological
zone and
substrate
Bioregion
Level 4
Functional
habitat
Level 5
Biotope
Level 6
Subbiotope
Level 7
Each major substrate class is coupled with each
major zone.
Regions characterised by temperature and salinity.
Finer divisions of substrate, zone, bioregion,
salinity, energy or other physical factor used and/or
main biological ‘life-form’ (e.g. kelp forest, mussel
beds).
Habitat defined by a dominant or characteristic
species or by consistent multi-species characteristics
or by an assemblage (community or biocenosis) and
by distinctive habitat features, which together, allow
distinction from neighbouring types.
Habitat defined by more subtle variation in species
composition, coupled with associated physical
differences
Due to proposed restructuring, this level is not
needed
Zonation and substrate (level 2)
The first major division in the marine part of the EUNIS classification is based on major
biological zones (related to depth) and substrate type. The definitions of zones vary between
sea regions. Table 2 shows the agreed zones and substrate classes.
Table 2: Zones and substrate classes to be used for the marine component of the revised
EUNIS habitats classification.
Zone
Hard
Rock
Other
Coarse
Mixed
Soft
Sand
Mud
Other
Littoral
Infralittoral
Circalittoral
Aphotic* Bathyal
Abyssal
* Aphotic as shown is a simplification and there can be photic communities in the upper
Circalittoral, for example in the Atlantic there can be a narrow zone of sparse erect algae.
Photic
Notes
Within the classification, the bathyal zone is considered to be the continental slope whilst the
abyssal zone starts at the base of the slope and is the plain. The circalittoral and bathyal zones
were not sub-divided into upper and lower sub-zones at level 2 as no consistent and
ambiguous definition for these sub-zones could be established for all European seas.
It was agreed to retain the four main sediment classes as there was insufficient evidence to
change these or their boundaries at present.
Within the substrate classes, for hard seabed ‘Other’ is primarily biogenic reefs that create a
hard compact substrata (regardless of the underlying substrate) but may also include other
types of ‘concretions’ (e.g. HELCOM units for mettalliferous nodules or methane-derived
authigenic carbonates associated with methane seeps). For sedimentary seabed, ‘Other’ refers
to habitats where the vegetation covers or transforms the underlying substrate, e.g. Posidonia
beds where the Posidonia effectively becomes the substrate (to the extent that the ‘original’
substrate cannot be identified) and saltmarsh habitats. It was acknowledged that these two
‘Other’ categories would need to be associated with clear identification criteria/thresholds and
may need to accommodate some other types which cannot readily be assigned to the main
substrate types.
Biogeographical regions (level 3)
It was agreed that level 3 should reflect the main biogeographical regions of Europe’s seas
based on their distinct combinations of salinity and temperature regimes. The following
regions were agreed;Arctic, Baltic, Atlantic, Mediterranean and Black Sea.
Some further work is required to define boundaries between the regions and it was agreed that
further consideration is needed to decide if an extra region for Macaronesia/South Atlantic is
justified (see Dinter 2001).
Biogeography was included below zone/substratum to ensure categories at level 2 are
consistent across the whole of Europe. The introduction of bioregions at level 3 gives some
flexibility for each region in how best to structure its level 4-6 types. However it is
recommended that, as far as possible, the structure and types included at level 4 are similar (or
the same) in nature to facilitate comparability and mapping between the bioregions.
Accommodating new habitat typologies
The current EUNIS classification incorporates habitat classes from several regional/national
classifications and inventories (e.g. Barcelona Convention, Britain & Ireland, HELCOM). In
recent years there have been several additional national/regional classifications published
whilst some of the existing classifications have been revised.
It was agreed that the revision of EUNIS should take these classifications into account in two
phases and only accommodating regionally agreed classifications (i.e. not national
classifications):
1. By 2014:
• Baltic Sea (HELCOM 2013)
• Atlantic deep sea review from Plymouth 2012 workshop - agreed typology – 101
types (in prep by Kerry Howell)
• Macaronesia -Azores & wider typology available – 81 new types by Tempera et al
(2013) (includes 32 deep sea linked to Kerry Howell’s deep sea list noted above).
Consider types from MeshAtlantic, coordinated input from Madeira and Canaries is
required to ensure all Macaronesia is covered properly. .
2. Future:
• Atlantic Iberia/Bay of Biscay - Typologies from France and Spain have been
published recently by national authorities and it was agreed that a regional review
process is required involving FR, ES, PT. This review should also consider the
inclusion of new types proposed through the MeshAtlantic project. The French
typology also includes habitats from the English Channel and North Sea which will be
submitted for consideration.
• Mediterranean & Black Sea – Work from EUSeaMap should be integrated together
with new typologies from France and Spain. The COCONET FP7 project1 was
identified as a potential source of useful information.
• Northern Atlantic/Arctic – The recent Norwegian habitat classification should be
considered for incorporation, further information may be needed for Iceland and the
Faroes, the Arctic Council might be a useful partner for this sea area.
It was also agreed that the EEA and the ETC/BD would be involved in any regional processes
to ensure a coordinated and coherent approach.
There is also a need to define how these new proposals can be brought forward to the EEA
and ETC/BD. All new habitat types being proposed must have a minimum level of
documentation through completion of the template available on the MESH web site2.
The EEA stated that any new typologies submitted for inclusion in EUNIS should have
already been agreed across the whole bioregion. The EEA and the ETC/BD will not be
responsible for organising workshops to get regional agreement on typologies; this will need
to be done through other existing platforms or projects.
Order of habitat types
Given the large number of habitat types (>1000 at present) a systematic approach to ordering
the types within each level was agreed as proposed in Table 3. For habitat naming, the same
parameters can be used but in reverse order.
Table 3: Order of habitat types
Level
2
2
3
4-6
4-6
4-6
4-6
Parameter
Substratum
Biological zone
Bioregions
Energy (wave/tidal)
Salinity
Temperature
Light
Order
Hard (rock) to soft (mud)
Shallow (upper littoral) to deep (abyssal)
North to south (anti-clockwise around Europe)
High to low
High to low
High to low
High to low
Other issues
Topographic features of the deep sea
Features such as canyons and seamounts (classes A6.7 and A6.8) should be moved to the
level 1 group ‘X habitat complexes’.
Pelagic habitats
1
2
http://www.coconet-fp7.eu/
http://www.searchmesh.net/default.aspx?page=1623
The current treatment is not satisfactory; a revision based on water masses should be
developed.
Coastal habitats
There are some supralittoral habitat types currently in ‘B: Coastal habitats’ which might be
better placed under ‘A: Marine habitats’; for example ‘B3.1: Supralittoral rock (lichen or
splash zone)’. Annabelle Aish (MNHN) will produce a list of possible changes based on the
French typologies but any change will require discussion with those responsible for the
terrestrial sections of the classification.
Timetable
What
Who
Draft meeting report ->comment by workshop
Doug
Final meeting report
Doug
Revise proposal v0.5, esp. L4 and share with
workshop
Finalise proposal v1.0 (clean new list + track
changes list) based on meeting; associated paper to
explain rationale
Revised proposal
ETC/BD +DWC
ETC/BD
Accommodate possible comments to give v2.0
EEA formal consultation with
EIONET, for information to
other interested groups (e.g.
MSFD, MEG, RSC, ICES)
ETC/BD
Peer review of final proposal
EUNIS marine expert group
Prepare web documentation/application
EEA
Finalised proposal v3.0
By
when
mid
Dec.
2013
7 Jan
2014
March
2014
April
2014
June
2014
Oct.
2014
Nov.
2014
Dec
2014
Dec.
2014
References
Connor, David (2013) Proposal for a revision of the EUNIS marine habitat classification.
Unpublished report
Dinter, W.P. (2001). Biogeography of the OSPAR Maritime Area: a synopsis and synthesis of
biogeographical distribution patterns described for the North-East Atlantic. Federal Agency
for Nature Conservation: Bonn. ISBN 3-7843-3818-6. 167, XVI pp.
Galparsoro, I. (ed) (2012). Using EUNIS Habitat Classification for Benthic Mapping in
European Seas. Revista de Investigación Marina, 19(2)
Ibon Galparsoro, David W Connor, Ángel Borja, Annabelle Aish, Patricia Amorim, Touria
Bajjouk, Caroline Chambers, Roger Coggan, Guillaume Dirberg, Helen Ellwood, Douglas
Evans, Kathleen L Goodin, Anthony Grehan, Jannica Haldin, Kerry Howell, Chris Jenkins,
Noëmie Michez, Giulia Mo, Pål Buhl-Mortensen, Bryony Pearce, Jacques Populus, Maria
Salomidi, Francisco Sánchez, Alberto Serrano, Emily Shumchenia, Fernando Tempera,
Mickaël Vasquez (2012) Using EUNIS habitat classification for benthic mapping in European
seas: Present concerns and future needs. Marine Pollution Bulletin 64:2630-2638.
Tempera, F., Atchoi, E., Amorim, J. Gomes-Pereira & J. Gonçalves (2013). Atlantic Area
Marine Habitats. Adding new Macaronesian habitat types from the Azores to the EUNIS
Habitat Classification. Technical Report No. 4/2013 - MeshAtlantic, IMAR/DOP-UAç,
Horta, 126pp.
Participants
Name
Lena Avellan
Kerry Howell
Touria Bajjouk
Ibon Galporsoro
Frederico Cardigos
Gerard Bellan
Organisation
External
HELCOM
University of Plymouth, UK
IFREMER
AZTI, Spain
University of Azores, Portugal
Institut Méditerranéen de Biodiversité et d’Ecologie Marine
et Continentale, France
Hellenic Centre for Marine Research
Maria Salomidi
European Commission
David Connor
Marine Environment & water industry (C2)
DG Environment
EEA
Rania Spyropoulou
EEA project manager
Eva Gelabert
Mette Lund
ETC/BD
Douglas Evans
ETC/BD core team
Megan Parry
JNCC
Giulia Mo
ISPRA
Eva Salvati
ISPRA
Annabelle Aish
MNHM
Invited but not able to attend
Enric Ballesteros
Centro de Estudios Avanzados de Blanes, Spain
Pal Buhl-Mortesen
Institute of Marine Research, Norway
Valentina Todovra
Institute of Oceanology, Bulgarian Academy of Sciences,
Bulgaria