Evaluation of the direct impacts of coastal development on littoral marine life

Fabrice Javel, Alexandre Meinesz, Sébastien Longepierre, Jean de Vaugelas

Laboratoire Environnement Marin Littoral, Université de Nice Sophia Antipolis (FR)

Human cities and activities increasingly develop on the littoral zone. This phenomenon, named "littoralisation", induces a very high level of anthropic pressure. Along the French Mediterranean coast and especially on the French Riviera, urbanisation, tourism and anti-erosion equipments represent the major causes of destruction and degradation of shallow benthic communities. The shallow benthic zone (0 to 50 m deep), when compared to the wide open ocean (pelagic zone), is a small surface restricted to a very narrow belt, as rocky coasts are steep with numerous vertical cliffs. Most of man-made coastal equipments are built on this highly diverse and rich narrow belt, therefore destroying, in an irreversible way, highly biodiverse biocenosis, such as Posidonia oceanica meadows.

MEDAM project

The MEDAM project aims at evaluating the direct impact of this coastal development on shallow benthic ecosystems. Using GIS, the areas of coastal equipment are measured and compared with those occupied by the native benthic ecosystems. These data are organized in a complete Geodatabase gathering all the thematic layers (natural vs. artificialised coastline, covered/built areas, etc.) and published on the Internet (http://www.medam.org). With its on-line, free access GIS functions, this web site allows one to instantly visualise the areas under pressure and may access to descriptive statistics on the impact of man-induced disturbances, at different "administrative" scales (town, county, region, national) and for the various types of equipment involved (harbours, dikes, artificial beach, anti-swell reefs, etc.).

This project is supported by the 'Agence de l'Eau Agence de l'Eau Rhône-Méditerranée-Corse', the 'Direction Régionale de l'Environnement Provence-Alpes-Côte d'Azur' and the 'Conseil Régional Provence-Alpes-Côte d'Azur'.