MACROPHYTE BIOLOGICAL METHODS USED IN THE STUDY OF THE EXCHANGE BETWEEN THE RHINE RIVER AND THE GROUNDWATER

The purpose of this study is to demonstrate the efficiency of two biol ogical methods in the study of the exchange between the canalized Rhin e river and its riverside aquifer. The infiltration of Rhine water int o the groundwater is revealed by a high level of eutrophicants and the micropollutant mercury. One method made use of the aquatic macrophyte communities as bioindicators of the degree of eutrophication based on phosphorus and nitrogen, and the second method, the capacity of the b ryophytes to accumulate mercury. The results obtained with both method s show that bioindication using autochthonous aquatic macrophyte speci es can be used as an efficient method in river-groundwater exchange in vestigation. (C) 1997 Elsevier Science Ltd.