DIATOMS AND DIATOM INDEXES IN THE NETWORK S FOR QUALITY MEASUREMENT OF FRENCH WATERCOURSES - SHORT HISTORY AND FUTURE

The use of diatoms and diatom indices in the networks for measurement of the quality of French watercourses was initiated on the Seine in 19 70. As from 1990, applications in the Rhone-Mediterranee-Corse, the Ar tois-Picardie, the Rhin-Meuse and the Adour-Garonne basins reflected a renewed interest. In 1994, the six French Water Agencies associated w ith CEMAGREF to elaborate a practical diatom index liable to be used r outinely in the whole French territory, and to promote and facilitate its use in monitoring networks. This diatom index should take its plac e next to the Global Biological Standardized index in the biological s ection of the future quality assessment system for watercourses, at pr esent being elaborated. Further developments should, therefore, focus on the consolidation of this index in France and on tests in different European countries.