WHY MEDAM ?
1. Damage to the marine environment
The destruction of the habitat is at the very summit of the hierarchy of damage to the biodiversity of the planet, ranking even above the impact of invasions of allogenic species, chemical or bacteriological pollution or the over-exploitation of living natural resources. The impact of major climatic changes will soon have to be taken into account in this ranking (Chapin et al., 2000).
2. The destruction of habitats in marine environment by coastal development
Damage to the marine environment that is underestimated
Each land reclamation from the sea destroys an underwater habitat by building over or enclosing a body of water. A high density of reclamations on small shallow bottom areas represents quantitatively a major form of damage to the underwater environment. The destruction caused is irreversible.
MEDAM : THE INVENTORY
Assessment of the overall impact of reclamation from the sea has been undertaken on the basis of an exhaustive inventory :
- of the natural coastline (historical survey prior to any reclamation),
- of the original surface areas of shallow bottoms (historic surface areas: prior to any reclamation). The bathymetric ranges 0 to -10 m and -10 m to -20 m have been taken into account,
- of all reclamation greater than 100 m² (harbours, landfills, dykes, breakwaters, groynes, etc.). The artificialised coastline and the areas occupied by constructions are included in the inventory.
MEDAM : THE TWO-FOLD IMPACT
An innovative impact assessment
Coastal development is generally assessed subjectively, by considering the integration in the landscape advantages of the reclamation, and pragmatically, by highlighting the economic advantages generated.
Ecological impact
The ecological impact is assessed by comparison of the areas reclaimed from the sea by construction with the original area of the coastal shallow bottoms (from 0 to -10 m, from -10 m to -20 m), the richest habitats in the marine environment. This assessment provides the basis for estimating rates of destruction of coastal ecosystems by bathymetric range. The negative impact outside the reclamation area is not taken into account.
Impact on the landscape
The landscape impact is assessed by comparison of the artificialised coastline with the coastline prior to any reclamation (original coastline). This assessment provides the basis for estimating rates of artifialisation of the coastal area.
MEDAM : GEOGRAPHICAL RANGE
The MEDAM data base covers the whole of the French Mediterranean coast (excluding lagoons, except for the Étang de Berre). The Principality of Monaco, as an enclave within French territory, is included. All data are presented on the basis of administrative divisions: country (France and Monaco), Regions (Provence-Alpes-Côte d’Azur, Corsica and Occitanie), départements (counties) (10) and communes (municipal or rural district) (183). The subdivision of the data on the basis of European water masses (50) (Framework Directive ‘Water’ of the European Parliament) is also given.