Influence des traitements phytosanitaires sur les biocoenoses du phytoplancton limnique

Abstract

We used specific diversity of phytoplankton and chlorophyll concentrations as a measure of algal biomass in ponds located in agricultural areas where pesticides and fertilizers are currently used and in natural meadows where pesticides spraying has never occurred .A comparison of the biocoenotic structure of the primary producers in the two types of ponds shows conspicuous differences . Species richness is higher in meadow ponds (25 species) than in agricultural area ponds (10 species) . The chlorophyll levels are reduced in agricultural area ponds . These effects could be ascribed to contamination by pesticides . 269

Proposal of ecotoxicological criteria for the assessment of the impact of pollution on environmental quality†

“…In our own laboratory some of my collaborators have used the method of the Chlorophyl concentration for appraising the effects of water pollution of ponds located in areas where surrounding fields had been sprayed with herbicides on the density of phytoplancton (Goacolou and Echaubard, underpress). 6 The primary productivity can be assessed from this data as well. Usually in water bodies the assessment of primary productivity of phytoplancton is achieved by the use of the 14C-carbonate method.…”