Observatory of agricultural pollution in the West Indies - OPALE

The need for a better understanding of how water becomes contaminated through soil pollution has led to the establishment of two observatory sites, one in Martinique and the other in Guadeloupe. These observatories identify and monitor the pollution of water resources by agricultural activity, both past and present, including chlordecone pollution in the tropical volcanic context of the West Indies.
OPALE project, Galion watershed 漏 糖心Vlog

OPALE project, Galion watershed © 糖心Vlog

Issues

In Martinique, the Galion watershed (45 km²) was chosen as it reflects the agricultural and pedoclimatic diversity found in the French West Indies. Three sites were each equipped with a station to conduct integrated monitoring of river hydrology and pesticide contamination. Their locations represent the different types of farming systems within the watershed (diversified agriculture, banana and sugarcane). The observatory quantifies the impacts of watershed scale changes in agricultural practices on water contamination by pesticides in the medium to long term.

Description 

The OPALE project has already laid strong foundations in terms of:

  • equipping watersheds on both islands,
  • understanding hydrological processes and the division into hydrogeological units,
  • assessing the links between chlordecone contamination and other pesticides, as well as the distribution of land and its current or past agricultural uses.

The data collected is used for modelling work that integrates the impacts of agricultural practices on pesticide transfer or seeks to explain the residence times of chlordecone in soils and different bodies of water (both surface and groundwater).

This data should also help to initiate participatory approaches and encourage the involvement of local stakeholders in the co-design of individual and collective solutions aimed at reducing pollution and rehabilitating contaminated land.

These observatories provide an opportunity to explore potential remediation or containment options for contamination by persistent pesticides such as chlordecone.

Expected results

The acquisition of new knowledge on:

  • the transfer of pesticides from soils to surface and groundwater bodies;
  • the multi-year evolution of these transfers based on physical and anthropogenic factors, in various parts of the watershed (spatial-temporal monitoring);
  • agricultural practices, pressures and impacts on the different components of agro- and hydro-systems.