The EMODnet broad-scale seabed habitat map for Europe

The EMODnet broad-scale seabed habitat map for Europe provides the community with a comprehensive, free and ready-to-use broad-scale map of physical habitats, harmonising mapping procedures and fostering a common understanding among seabed mappers in Europe. The map is also known as EUSeaMap.

The EUSeaMap broad-scale predictive mapping methods are repeatable and ensure that the predictive maps can continue to be improved in the future. EUSeaMap is available in the EUNIS and MSFD Benthic Broad Habitat types classifications.

 

MSFD EUSeaMap 2016

EUSeaMap 2016 in the MSFD BBHT classification. View or download the map

 

Building on the highly successful INTERREG IIIB-funded MESH and BALANCE projects, phase 1 of EMODnet Seabed Habitats (2009-2012) improved and harmonised the broad-scale physical habitat map across the Celtic Seas, Greater North Sea and Baltic Sea, as well as generating the very first broad-scale map of the western Mediterranean. In phase 2 (2013-2016), the coverage of the maps was extended to all European seas and the existing maps were improved. Updates and a further increase in extent to the Barent Sea will take place in the current phase (2017-2020). 

 

EUSeaMap coverage 2012-2019

EMODnet Seabed Habitats broad-scale habitat map coverage in Phase 1 (EUSeaMap 2012)
and Phase 2 (EUSeaMap 2016), and areas to be covered in phase 3 (2017-2020)

 

The data layers and confidence maps produced by the project partners, are freely available through the EMODnet Seabed Habitats Map Viewer

 

  • Benefits of a broad-scale habitat map

    In order to most benefit from the potential offered by the European marine basins in terms of growth and employment, and to protect the marine environment, we need to know more about the seafloor. European Directives, such as the Marine Strategy Framework Directive (MSFD), call for a full-coverage seabed habitat map of all European seas. In general, habitat maps are very costly and time consuming to produce from survey. The creation of a detailed habitat map involves surveying the seafloor with sonar equipment and collecting samples or photos of the seabed, before analysing and integrating these data types to generate a map. It can take several years from planning a survey to completing a detailed map. By contrast, broad-scale mapping of seabed substrate at a low resolution combined with using modelling techniques to classify habitats in terms of physical parameters is an efficient way to meet the need for a full coverage habitat map at a reasonable cost and a shorter time frame.

    EUSeaMap products have been used for assessing and reporting the status of European seas, designing ecologically coherent Marine Protected Area networks, establishing monitoring programmes for seabed habitats and informing marine planning. For more information and some examples of application of EUSeaMap products, see Use Cases.

  • Principles behind making broad-scale seabed habitat maps

    It is possible to produce a ‘predictive map’ of expected seabed-habitat types by combining a series of proxy measurements, such as water depth and light levels amongst others, using statistical analysis and Geographical Information System modelling.

    Principal drivers for seabed habitat distributions include the type of seabed substrate (rock, mud, mixed sediment, etc.), depth, light availability and the energy of water movements. To describe the variation in environmental conditions with depth, EUNIS divides subtidal habitats into zones: Infralittoral, Shallow Circalittoral (or Circalittoral), Deep Circalittoral and Deep Sea. In this project we further subdivide the Deep Sea zone into bathyal and abyssal zones, following scientific literature and recognising the diversity of these huge areas.

    The division of marine sublittoral habitats into biological zones (©MESH Atlantic Blue Box, 2013).

     

    The division of marine sublittoral habitats into biological zones (©MESH Atlantic Blue Box, 2013).ther factor that can be fundamental in driving habitat types is the degree of exposure to wave and water-current energy. For some more enclosed basins other parameters, such as salinity, oxygen levels and temperature of water at the seabed are also considered to be fundamental for habitat mapping.

  • Generating the maps

    During the first phase of EMODnet Seabed Habitats (2009-2012), a consistent method was developed to take into account the diverse range of seabed habitats found in different regions.

    The first step is to acquire the best-available spatial data for several environmental variables. This includes data provided by EMODnet Geology and EMODnet Bathymetry. The data are organised and harmonised into pixelated images divided into classes. These data can be combined by ‘layering’ the data in GIS to create a combined output describing the habitat.

     

     

    Illustration of how a predictive habitat map can be created by ‘layering’ data in GIS.

    The principal input layers are the type of seabed substrate and the biological zones. Depending on the basin, layers of hydrodynamic energy levels, salinity and/or oxygen are also produced. For example the hydrodynamic energy layer is divided into ‘Low’, ‘Medium’ and ‘High’ classes.

     

    Example of an input layer: biological zones. Input layers are also useful per se and are available online through the EMODnet Seabed Habitats Map Viewer

     

    The EUSeaMap model was developed in ESRI™ ArcGIS ModelBuilder and can be saved and executed multiple times, which ensures that the systems are repeatable and easily updated when new layers or methods are available.

    As well as careful evaluation of contributing data, and refining statistical methods for its interpretation, during the creation of the maps it is necessary to define meaningful thresholds for likely changes in habitats: in each input layer these are used to define the boundaries between classes, where the change in the physical conditions reaches a critical point that defines an expected change in habitat type (at the map-scale adopted in EUSeaMap, 250mx250m blocks). For example, the infralittoral zone is the area of the seabed where photosynthetic algae is able to grow. This is mapped by finding a threshold value of light at the seabed that best fits observations of this limit in the field. More infromation on EUSeaMap methodology, including EUSeaMap 2016 technical report, are available in the documents section.