Título:
Exchange between systems: from river catchments to coastal marine waters
Resumo:
The European Water Framework, promulgated in 2000, proposed a global approach with a precise schedule and a clear objective: the long term protection of aquatic environments and resources and, especially for the rivers, their ecological integrity from the source to the mouth. For a long time, the ‘ecosystem approach’ appeared a good way in terms of research to show, at a landscape level, the reality of a link between the functioning of such different systems as watersheds, rivers, streams, estuaries and marine coastal water systems. Much research on exchange, transfers of energy and materials between these systems have proved that, finally, the water quality in rivers and in the sea as well as and the functioning of aquatic ecosystems (freshwater and marine ecosystems) depend on the evolution of land cover and land use of the watersheds. The development of intensive agriculture that takes no account of the environmental issues, regularly destroys the integrity of biogeochemical and water transfers between land and ocean. It is one of the main causes of the disturbance of the functioning of aquatic ecosystems. In Celtic Countries, at a local scale, the Mont-Saint-Michael bay and its watershed appears as an appropriate model to analyse the multiple consequences of land use changes in the watershed, due to agriculture, on the deterioration of aquatic ecosystem and water quality. Brittany in its entirety seems to be one of the best models to study the same processes at a regional scale.
Autores:
Jean Claude Lefeuvre, Eric Feunteun