Medam is a database of the Marine Strategy Framework Directive (MSFD) monitoring program for the Mediterranean Sea, "Benthic Habitats and Seabed Integrity" component.
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The Medam website has been integrated into the European Sea Atlas of the European Commission.
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The Medam website has been updated significantly in 2016 and 2017.
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MEDAM is the sister website of MEDAMP, the observatory of the protection of biodiversity :
Any quotation or use of elements of this data management system should be mentioned as "MEDAM Université Côte d'Azur CNRS ECOSEAS"


Built-over areas

The built-over areas are the parts that are no longer submerged. This is the direct impact of construction on the sea bottom. The under-sea habitats that have been built over are thus irreversibly destroyed. The landward delimitation of the built-over area is based on the original coastline (natural). It should be pointed out that we have not taken into account submerged parts of constructions or pontoons built on piles.

En grisé les surfaces couvertes
The built-over areas

Enclosed water area

The enclosed water area corresponds to the body of water enclosed by construction (port, port of refuge, artificial beach). The delimitation of the enclosed water area is based (i) on the seaward side, by the ends of the seawalls (ii) on the landward side, by the inner contour of the jetties quays or rockfill. The enclosure of this water mass irreversibly upsets the enclosed ecosystems. The body of water, in particular in the case of harbours, is the receptacle of various kinds of pollution such as heavy metals (from anti-fouling paint on boats), hydrocarbons, macro-detritus and various organic substances (from waste water from inhabited boats). Given that the ecosystems originally situated on these spaces have been definitively enclosed by the constructions and have been irreversibly destroyed or disturbed, these areas are taken into account for calculation of the ecological impact rate.

Exemple de plan d’eau endigué.
Example of an enclosed area of water.


Area reclaimed from the sea

This is the sum total of the surface area of built-over areas and enclosed bodies of water.


Coupe transversale d'un port montrant la surface gagnée (les surfaces couvertes + surfaces de plan d’eau endigué)

Cross-section of a harbour showing the reclaimed area (built-over areas + enclosed bodies of water)

Particular cases

Areas of water in spaces excavated on land. When a construction has been built by digging part of the space for a body of water out of the land, we have dissociated the ‘excavated body of water’ from the ‘enclosed body of water’; only the ‘enclosed body of water’ has been taken into account for the ecological impact calculations

Accumulations of sediment caused by construction. This is the surface area representing the emerged part of the sediment accumulated against a construction because of alteration of the currents and local hydrodynamic forces. These surface areas are not taken into account in the impact assessment since they are mobile sediments that may have come from the erosion of another part of the coast (in cases where the marine domain is extensive).


 Exemple d’accumulation de sédiments contre un port.
Example of accumulation of sediment against harbour structures.



An image data base has been developed in order to present visually the changes in the coastline at the sites of reclamation redevelopment schemes.


1628 photographs are available at this site, with ongoing updating of the image bank. The photographs may be recent or more historical (views of the coast prior to reclamation have been sought). Some are photographs taken from the air others at ground level (sea or land).


The images made available are of low resolution. The photographers are cited and may in some cases be contacted by e-mail (list of photographers). Any new photos or similar documents are welcome: contact us to upload them ! (aims, procedure, conditions)


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Access the cartographical data base to view the contour lines of all the reclamations and the contours of all the bathymetric and administrative limits.


Access data on the characteristics, description, year of redevelopment, illustrations and localisation of each reclamation > 100 m².


Access the historical record data base: the construction of each structure or part of a structure has been dated. This data provides the basis for showing on bar charts the progression over time of reclamations and their impact on the basis of administrative units (country, region, county ( département), municipal and rural district (commune) or ECD water mass).


For all French Mediterranean coasts (excluding Monaco and the Etang de Berre) (see ‘details’ for noteworthy regional or more local particularities).

MEDAM Inventory :

Original coastline : 2 062 km (> see details)

Surface area of shallow water bottoms prior to any reclamation (> see details) :

Between 0 and -10 m : 80 723 ha soit 807 km²

Between -10 m and -20 m : 88 046 ha soit 880 km²

Between 0 and -20 m : 168 769 ha soit 1 688 km²
Between -20 and -50 m : 330 030 ha soit 3 300 km²


Number of reclamations (>100 m²) : 1 050 (> see details)


Coastline ‘artificialised’ by reclamation : 223.02 km (> see details)

Surface areas reclaimed by these redevelopments (> see details) :

Between 0 et -10 m : 4 226.13 ha

Between -10 m et -20 m : 903.70 ha

Between 0 et -20 m : 5 129.83 ha


MEDAM Impacts :

Rate of ‘artificialisation’ of coastline (linear) : 12.27 % (> see details)

Rate of irreversible destruction of shallow water bottoms by reclamation (> see details) :

Between 0 et -10 m : 5.24 % 

Between -10 m et -20 m : 1.03 % 

Between 0 et -20 m : 3.04 %


Progression :
A step in the right direction: a clear slowing down of reclamation from 1985  (> see details).