Journal of Environmental Biology

Effect of pesticides used in banana and pineapple plantations on aquatic ecosystems in Costa Rica

No?l J. Diepens^1,2*, Sascha Pfennig¹, Paul J. Van den Brink^2,3, Jonas S. Gunnarsson⁴, Clemens Ruepert¹ and Luisa E. Castillo¹

¹Central American Institute for Studies on Toxic Substances (IRET), Universidad Nacional, Heredia, 83-3000, Costa Rica

²Department of Aquatic Ecology and Water Quality Management, Wageningen University, Wageningen University and Research Centre, P.O. Box 47, 6700 AA Wageningen, the Netherlands

³Alterra, Wageningen University and Research Centre. P.O. Box 47, 6700 AA Wageningen, the Netherlands

⁴Department of Ecology, Environment and Plant Sciences, Stockholm University, Stockholm, SE-106 91, Sweden

*Corresponding Author E-mail: noel.diepens@wur.nl

 Publication Data

Paper received:

27 April 2013

Revised received:

24 June 2013

Accepted:

05 September 2013

Abstract

Current knowledge on fate and effect of agricultural pesticides comes is mainly from temperate ecosystems. More studies are needed in tropical systems in order to assess contamination risks to non-target endemic tropical species from the extensive use of pesticides e.g. in banana and pineapple plantations. In this study, acute laboratory toxicity tests with organophosphate pesticides ethoprophos and chlorpyrifos were conducted on two Costa Rican species, cladoceran Daphnia ambigua and fish Parachromis dovii. Tests showed that chlorpyrifos was more toxic than ethoprophos to D. ambigua and P. dovii and that D. ambigua was also more sensitive than P. dovii to both pesticides. Additionally, bioassays were performed by exposing D. magna and P. dovii to contaminated water collected from the field. Chemical analyses of field water revealed that fungicides were generally the most frequent pesticide group found, followed by insecticides/nematicides and herbicides. The bioassays and values obtained from the literature confirmed that D. magna was more sensitive to pesticide contamination than P. dovii and that D. ambigua was more sensitive than D. magna, suggesting that the native cladoceran is a more suitable test species than its temperate counterpart. Species sensitivity distributions showed no significant difference in sensitivity between tropical and temperate fish and the arthropod species exposed to chlorpyrifos in this study. Choline esterase activity (ChE) was measured in P. dovii in laboratory tests in order to assess the applicability of this biomarker. ChE inhibition in P. dovii was observed in the laboratory at levels below the LC₁₀ of both ethoprophos and chlorpyrifos, confirming that ChE is an efficient biomarker of exposure. Both indigenous Costa Rican species used in this study were found to be suitable standard tropical test species. Further studies are needed to investigate how protective the safe environmental concentrations, derived from LC₅₀ of native tropical species, are for protecting tropical aquatic natural communities.

Key words

Acute toxicity, Bioassays, Chlorpyrifos, ChE inhibition, Ethoprophos, Tropical aquatic ecosystems

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