Abstract

Coastal marine environments are particularly exposed to pollutants emanating from human activities such as agriculture. In the French West Indies, banana, sugarcane and pineapple cultivation leads to significant use of phytosanitary products to combat pests and diseases. These chemicals follow the path of the water cycle, reaching rivers and aquifers, then coastal waters through run-off, infiltration and resurgence (Charlier et al., 2008). To assess the level of contamination in the environment, in 2016 the "OPALE" observatory of agricultural pollution initiated a monitoring of surface and groundwater quality in two watersheds in the French West Indies (Pérou-Pères in Guadeloupe and Galion in Martinique) and since 2022 in coastal waters. Thus, the main objectives of OPALE are to monitor and make available data on contamination levels and study the transfer of pollutants between the different aquatic compartments (surface waters, groundwaters and coastal waters). The present study describes the functioning of the observatory, as an example of device that can be deployed to follow agricultural pollutants from the catchment areas to coastal waters, and provides first results on the levels of contamination.