Environmental impact of pesticide use in a tropical aquatic ecosystem (case study in a banana plantation in Costa Rica)
It is estimated that more than a third of the pesticide volume imported in Costa Rica is used on banana plantations, fungicides are applied up to 40 times a year by airplane, while highly toxic nematicides are applied up to 4 times a year directly to the ground. The intensive use of pesticides, together with the type of application, the toxicity of some of the compounds used, the drainage system of the banana plantations and the heavy rainfall, make the water bodies in the area vulnerable. Although environmental problems like fish and crayfish mortalities have occurred frequently, studies on the fate and environmental impact of pesticides on the aquatic ecosystem of agricultural areas of Costa Rica have not been carried out previously. In general such studies are scarce in tropical regions. The study presented here assesses the impact of pesticide use on a tropical aquatic ecosystem using an integrated approach that takes into account environmental levels of pesticides and effect on aquatic organisms. The biological effects are being assessed by acute and chronic toxicity studies, and the determination of the biodiversity of macrobenthic organisms. The study sites are located in the basin of the Suerte River in one of the main banana growing areas of the country. This river drains into the canals of the national Park of Tortuguero, a protected area of great biological richness and refuge for several endangered species. The sampling sites selected include main drainage ditches in the banana plantation, streams and several points in the river down to the canals of Tortuguero. In each sampling site, samples of water, sediments and aquatic organisms are collected bimonthly for residue analysis. Water is also collected in the same points for acute and chronic toxicity testing. Macrobrachium rosenberii and Thamnocephalus platyurus are used as test organisms in the acute studies. Genotoxicity is used as an endpoint for the chronic studies. Artificial and natural substrates are used to study the biodiversity of macrobenthic organisms. Residues have been found in the surface water of the drainage channels. The most frequently found compounds were the fungicides thiabendazole and propiconazole and the insecticides chlorpirifos and terbufos. The approach used in this study will be further evaluated in order to develop a model for the assessment of the environmental impact of pesticides adapted to tropical aquatic ecosystems.
| Main Authors: | , , , , , , , , , |
|---|---|
| Format: | biblioteca |
| Published: |
San José (Costa Rica)
1994
|
| Subjects: | BANANO, PLANTACIONES, PLAGUICIDAS, IMPACTO AMBIENTAL, CUENCAS HIDROGRAFICAS, CONTAMINACION QUIMICA, RIO SUERTE, COSTA RICA, |
| Tags: |
Add Tag
No Tags, Be the first to tag this record!
|