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).

In this context, the destruction of the shallow bottoms by reclamation and the disturbances resulting from the artificialisation of the coastline should be assessed with a view to monitoring and limiting them more effctively in the future. The aim of MEDAM is to assess the overall extent of this destruction of habitats.


But species and ecosystems also undergo locally other types of damage to biodiversity. In order to limit these other forms of damage, remarkable joint efforts have been deployed over the past few years from the scientific, administrative and legislative points of view.

Damage to the marine environment has an impact on our health and on our economy


It is worth pointing out that for the marine domain, the main forms of damage cited, taken into account and mediatised, are above all those linked to our health and our economy. The managers of the marine environment are particularly concerned with bacteriological or chemical pollution affecting the quality of bathing water or fishing production. At regional, national and European level, a range of monitoring measures, observation networks and increasingly restrictive legislation resulting in the reduction of the sources of pollutants have been introduced. .
In addition, efforts have been made with regard to the prevention and treatment of pollution affecting the natural aspect of the coasts, such as black tides or the accumulation of solid detritus (macro-detritus) on the beaches, as these are always highly damaging for the tourism economy.


Finally, efforts have been made at European Community level to regulate overfishing and to preserve the fishing economy on the basis of better management of the halieutic resources.


These forms of pollution and the over-exploitation of marine species have been the focus of a large number of scientific publications. All these forms of pollution are reversible and the impact that is most deleterious to the environment and the species is often highly localised.


The preservation of environments and species


Aside from preoccupations linked to health, tourism or fishing production interests, outstanding natural marine environments and endangered marine species are also given a good deal of attention, but the efforts deployed in these fields by the local authorities have progressed little over the years. The number of strictly protected marine areas (monitored sanctuaries where no catches are allowed) has changed little off the French Mediterranean coasts since a quantitative survey carried out in 1983 (Meinesz et al.. 1983) and the number of specialists of the marine environment in systemics and ecology in the university marine research centres has declined considerably.