Examples of intermediate scale maps
 

Probability distribution maps of macrobenthic communities covering the Belgian part of the North Sea

Probability distribution maps of macrobenthic communities have been produced covering the entire Belgian part of the North Sea (Habitat suitability EUNIS) from biological and sedimentological databases. A habitat model, based on discriminant function analyses was developed based on the biological dataset, comprising both species and environmental data. Median grain-size and silt-clay percentage were the most discriminating parameters. These variables were modelled on a grid of 250 m using advanced geostatistical tools. In GIS, the habitat model was applied on these datasets. Probability maps of the 4 macrobenthic communities were constructed. These were then translated into a EUNIS map. At present, not all of the macrobenthic communities can be attributed to a EUNIS class. Ecological validation proved highly successful.
 
GMHM4-56_provisional_EUNIS_habitat_sites.jpg
 
Provisional EUNIS habitat types as defined on the Belgian Continental Shelf (Ghent University).
 

Mapping EUNIS habitats along the Glénan Archipelago

The Glénan archipelago is known for both its outstanding geomorphological structure and its highly diverse benthic habitats. Numerous studies have been made on this sector, many of them specific and independent. The archipelago provides an optimal study area for general mapping of benthic habitats made by collating data from several sources (Glenan Archipelago Case Study).  A large number of remarkable habitats are located in the Glénan archipelago. There are extensive maerl beds at the centre and to the North-east of the archipelago. Zostera marina eelgrass beds are the main habitat in the centre of the sector. To the southwest of the principal islands, there is a large rocky flat, mostly colonised by macroalgae like kelp. Finally, although their surface area is limited, in the intertidal sector there are large belts of fucoids and large areas covered by fields of boulders that are particularly rich in terms of species present.
 
The baseline data were coastal orthophotography for the intertidal zone and shallows (depths less than 8-10 m), the SHOM's sedimentological G map, modified by photo-interpretation for shallow bottoms, along with observations made on hyper baric dives at greater depths. Samples were taken for granulometric analysis or sometimes the grain size class was visually estimated. Coastal orthophotographs (resolution 1 m) were processed by enhancement before being put into unsupervised categories. Ground-truthing was then used to classify each pixel of the image as a habitat type with respect to its spectral signature. Additional survey work included dual hydrographic LiDAR and very-high resolution side-scan sonar and multibeam, validated with grab sampling and video. SPOT satellite imagery was also available and many photographs. The habitats were described in accordance with the Natura 2000 typology given in detail in the Natura 2000 habitat manuals (2004).
 
GMHM4-57_benthic_habitats_in_glenan_archipelago.png
Benthic habitats in the Glénan archipelago. The map is a result of many different data sources. The final interpretation is translated into EUNIS classes (Ifremer).
 

Biotope characterisation, Bristol Channel

The Outer Bristol Channel Marine Habitat Study (Mackie et al., 2006) examined the biology and geology of the seabed in an area with potential as a marine aggregate resource. The infaunal distributions were most strongly correlated to depth and five sediment parameters. The biotope map was derived from a semi-quantitative cluster analysis of both infauna and epifauna, adjusted with reference to the seabed character and bedform map. The three main EUNIS infaunal biotopes were A5.242 (SS.SSa.ImuSa.FfabMag) in the predominantly fine sands of Carmarthen Bay, A5.124 (SS.SCS.ICS.HeloMsim) in the extensive NOBel Sands sandwave field, and A5.132 (SS.SCS.CCS.MedLumVen) in the predominantly gravely sediments of the SOBel Sands to the south. In many areas multiple biotopes co-occurred, and epifaunal biotopes A5.232 and A5.444 (hydroids) and A5.611 (Sabellaria spinulosa) were present as overlays, particularly on the more stable gravely sediments. The biotopes were defined as EUNIS or taken from the JNCC Marine Habitat Classification website.
 
The biotope map is primarily based on the biology at each sample position, adjusted with respect to a full-coverage seabed character map. The latter map has been constructed on the basis of side-scan sonar and multibeam imagery, validated with sampling and video imagery.
 
The Bristol Channel mapping is extensively described and illustrated in Mackie et al., (2006).
 
 
GMHM4-58_biotope_map_of_bristol_channel.jpg
Biotope map of the Bristol Channel integrating biological and environmental parameters. It is derived from cluster analysis and a seabed character and bedform map (Mackie et al., 2006).

All material variously copyrighted by MESH project partners 2004-2010

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