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 : www.medamp.org
Any quotation or use of elements of this data management system should be mentioned as "MEDAM Université Côte d'Azur CNRS ECOSEAS"

RATE OF ARTIFICIALISATION OF THE COAST BY RECLAMATIONS FROM THE SEA

While the rate of artificalisation of the whole of the French Mediterranean coast is 12,27 %, wide differences are apparent from region to region:
- For the coast of Languedoc-Roussillon, the rate is 17,06 %,
- for the coast of Provence-Alpes-Côte d’Azur (not including Monaco and the Etang de Berre), the rate is 21,98 %,
- for the coast of Corsica, it is 2,68 %.
Within regions or counties (départements), distinct differences are also apparent:
- for the coast of the département of the Gard, the rate is 17,25 %,
- for the coast of the Alpes-Maritimes, it is 35,35 %,
- for the coast of the Bouches-du-Rhône (not including the Etang de Berre), 0,00 %,
- for the coast of the Principality of Monaco, it is 88,96 %,
- for the coast of the Etang de Berre, 42,02 %,
- for the coast of Corse du Sud, 2,47 %.
Apart from the impact on the landscape, the artificialisation of the coast represents an impact with regard to the qualitative and quantitative distribution or species which only live at sea level. The ecosystems situated at sea level (superficial part of the infralittoral zone and of the mediolittoral zone) are constituted of species possessing:
- high tolerance for variations in temperature (during periods of anticyclone the species are above the water level and thus tolerate over the year the terrestrial variations in temperature (-5 °C at the coldest point of the winter to +40 °C in the sun) with sudden changes when they are underwater– where the temperature ranges from 12.5 °C to 27.5 °C)
- high tolerance of variations in salinity (during anticyclones, the species are above the water level and thus tolerate considerable variations in salinity: from 0 (when it rains) to +50 ‰ when the species are out of the water and the sea water which soaks them evaporates.
This ensemble of species highly adapted to live in this narrow strip of coast is not found anywhere else (underwater, the species are not at all tolerant of variations in salinity or temperature). Thus their habitat is strictly limited to a frieze of 0.5 m to 3 m width along the coastline.
Among these species developing in this small space, there are the large brown algae (Stramenopiles of the genus Cystoseira) and calcareous red algae forming over time concretions (Rhodophytes of the genera Lithophyllum and Titanoderma). The species of this kind which constitute the main biomass at sea level (and therefore serve as support or shelter for other animal or plant species adapted to this environment) recolonise very poorly the artificial substrates (concrete, rock, etc.) The inventory of the distribution of the Cystoseires off the French Mediterranean coast shows that less than 0.5 % of the artificial coastline has been recolonised by species of this kind (Thibaut et al., 2008,2009,2010 et 2011).
The artificialisation of the coast thus engenders a local decline of the biodiversity (quantitative and qualitative) at very long term.

trottoir lithophyllum sur roches naturelles

Pavement of concretions formed by the red algae (Rhodophyte) Lithophyllum tortuosum on natural rocks. (Photo : A. Meinesz)


ceinture cystoseira sur roche naturelle

Belt of brown algae (Straménopiles) Cystoseira stricta var amentacea on natural rock. (Photo : A. Meinesz)


exemple littoral articicialise film cyanobacteries

Example of artificialised coast with only a film of brown Cyanobacteria visible on the rocks at sea level (Photo : A. Meinesz)

 
 
 
 
 
 

PHOTOS

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

 

1627 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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CARTOGRAPHY

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

RECLAMATION SCHEMES

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

HISTORICAL RECORD AND PATTERNS OF PROGRESSION

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).

THE RECORD

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).

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