RATE OF IRREVERSIBLE DESTRUCTION OF SHALLOW BOTTOMS BY RECLAMATIONS
While the rate of irreversible destruction of shallow bottoms by reclamations for whole of the French Mediterranean coast is only 5.24% between 0 and -10 m, 1.03% between -10 m and -20 m and 3.04% between 0 and -20 m, wide differences are apparent between regions :
- Continental French Mediterranean coast (Languedoc Roussillon + Provence-Alpes-Côte d’Azur not including Monaco and Berre) :
between 0 and -10 m : 5.55%,
between -10 m and -20 m : 1.20%,
between 0 and -20 m : 3.23%.
+ Including : coast of Provence-Alpes-Côte d’Azur (not including Monaco and Etang de Berre)
between 0 and -10 m : 9.95%,
between -10 m and -20 m : 2.11%,
between 0 and -20 m : 5.73%.
+ Including : coast of Languedoc Roussillon
between 0 and -10 m : 3.83%,
between -10 m and -20 m : 0.43%,
between 0 and -20 m : 2.04%.
- Coast of Corsica :
between 0 and -10 m : 0.84%,
between -10 m and -20 m : 0.11%,
between 0 and -20 m : 0.48%.
- Principality of Monaco
between 0 and -10 m : 90.39%,
between -10 m and -20 m : 67.47%,
between 0 and -20 m : 81.67%.
- Etang de Berre
between 0 and -10 m : 3.73%,
between -10 m and -20 m : 33.76%,
between 0 and -20 m : 3.88%.
The département of Alpes-Maritimes (not including Monaco) is the most highly impacted :
between 0 and -10 m : 20.18%,
between -10 m and -20 m : 0.19%,
between 0 and -20 m : 12.69%.
The rocky coast situated between Menton and Martigues (département of Alpes-Maritimes + Monaco + Var + east of Bouches du Rhône) is particularly highly impacted :
between 0 and -10 m : 10.10%,
between -10 m and -20 m : 2.17%,
between 0 and -20 m : 5.84%.
The impact of reclamations is considerable on shallow bottoms because of the accumulation of occupied surface areas and the small extent of the original shallow bottoms. The 5282 hectares built over or enclosed are so many hectares of degraded or destroyed for ever. This means that the overall impact of reclamations from the sea should be considered as the major human impact on marine biodiversity on the coastal fringe of the French Mediterranean coast. It exceeds by a factor of 50 the accumulated degradation caused by all the urban or industrial waste between 0 and -20 m along the whole of the French Mediterranean coast (taking into account areas where more than 50% of natural species have disappeared because of this waste). These areas that have been severely degraded by urban waste are mainly localised in front of the outflows discharging on the surface waste waters from the Marseille conurbation (Calanque de Cortiou) and that of Toulon (Cap Sicié). But these two megapoles are now equipped with increasingly efficient sewage treatment plants so that the recolonisation of areas that were highly degraded in the past (less than 75 ha in all in front of these two sites) is in progress.
Because of its irreversible character, the destruction caused by reclamations from the sea are the major cause of the qualitative and quantitative impoverishment of the marine species of the littoral along the whole of the French Mediterranean coast, well ahead of reversible chemical or bacteriological pollution, well ahead of the temporary impoverishment of fisheries resources by fishing pressure that is still inadequately controlled.