Agricultural pesticides pose a continuous ecotoxicological risk to aquatic organisms in a tropical horticulture catchment
Pesticides are used throughout the tropics in large amounts to protect crops against pests and weeds. These chemicals may be lost to the aquatic environment and impair its ecological status and the water quality for human consumption. Despite intensive use of pesticides in many developing countries,...
| Main Authors: | , , , , |
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| Format: | Article |
| Language: | English |
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Elsevier
2023-04-01
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| Series: | Environmental Advances |
| Subjects: | |
| Online Access: | http://www.sciencedirect.com/science/article/pii/S2666765722001740 |
| _version_ | 1797884482032762880 |
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| author | Frederik T. Weiss Clemens Ruepert Silvia Echeverría-Sáenz Rik I.L. Eggen Christian Stamm |
| author_facet | Frederik T. Weiss Clemens Ruepert Silvia Echeverría-Sáenz Rik I.L. Eggen Christian Stamm |
| author_sort | Frederik T. Weiss |
| collection | DOAJ |
| description | Pesticides are used throughout the tropics in large amounts to protect crops against pests and weeds. These chemicals may be lost to the aquatic environment and impair its ecological status and the water quality for human consumption. Despite intensive use of pesticides in many developing countries, the knowledge of pesticide levels in aquatic ecosystems is often very limited. In this study, we try to fill this gap for an horticultural catchment of 35.9 km2 in Costa Rica, which is intensively used by small-holder farming for potatoes and vegetable production. We continuously monitored pesticides in the Tapezco river during two consecutive rainy seasons with passive sampling systems and screened for a broad set of polar and non-polar pesticides. Spatially distributed measurements revealed high pesticide concentrations of many fungicides, herbicides and insecticides throughout the watershed. Concentration ranges revealed little spatio-temporal variation. From an ecotoxicological point of view, the insecticide levels – notably chlorpyrifos and cypermethrin - were most critical. The observed concentration levels exceeded chronic environmental quality standards more than 100-fold at all sites. These high insecticide levels were partially reflected in the community composition of the macroinvertebrates. Available data revealed a poor status at two upstream locations according to the Costa Rican Biological Monitoring Working Party (BMWP-CR) Index and the SPEARpesticides index. However, the indices indicated a good quality at most downstream sites despite their high pesticide levels. The wide-spread occurrence of high pesticide levels demonstrated that the relevant sources and pathways existed throughout the catchment. Field observations and survey data showed the relevance of point sources due to poor pesticide handling as well as diffuse losses from fields, which are strongly enhanced by the steep terrain and linear structures like gullies connecting fields with the stream. Mitigation measures to reduce pesticide losses have to account for these different source-flowpath combinations. |
| first_indexed | 2024-04-10T04:07:20Z |
| format | Article |
| id | doaj.art-819f6c18f4544639b5c0ad0f69012b7f |
| institution | Directory Open Access Journal |
| issn | 2666-7657 |
| language | English |
| last_indexed | 2024-04-10T04:07:20Z |
| publishDate | 2023-04-01 |
| publisher | Elsevier |
| record_format | Article |
| series | Environmental Advances |
| spelling | doaj.art-819f6c18f4544639b5c0ad0f69012b7f2023-03-13T04:16:19ZengElsevierEnvironmental Advances2666-76572023-04-0111100339Agricultural pesticides pose a continuous ecotoxicological risk to aquatic organisms in a tropical horticulture catchmentFrederik T. Weiss0Clemens Ruepert1Silvia Echeverría-Sáenz2Rik I.L. Eggen3Christian Stamm4Eawag, Swiss Federal Institute of Aquatic Science and Technology, Überlandstrasse 133, 8600 Dübendorf, SwitzerlandCentral American Institute for Studies on Toxic Substances, Universidad Nacional, Heredia, Costa RicaCentral American Institute for Studies on Toxic Substances, Universidad Nacional, Heredia, Costa RicaEawag, Swiss Federal Institute of Aquatic Science and Technology, Überlandstrasse 133, 8600 Dübendorf, Switzerland; ETH, Zürich, SwitzerlandEawag, Swiss Federal Institute of Aquatic Science and Technology, Überlandstrasse 133, 8600 Dübendorf, Switzerland; Corresponding author.Pesticides are used throughout the tropics in large amounts to protect crops against pests and weeds. These chemicals may be lost to the aquatic environment and impair its ecological status and the water quality for human consumption. Despite intensive use of pesticides in many developing countries, the knowledge of pesticide levels in aquatic ecosystems is often very limited. In this study, we try to fill this gap for an horticultural catchment of 35.9 km2 in Costa Rica, which is intensively used by small-holder farming for potatoes and vegetable production. We continuously monitored pesticides in the Tapezco river during two consecutive rainy seasons with passive sampling systems and screened for a broad set of polar and non-polar pesticides. Spatially distributed measurements revealed high pesticide concentrations of many fungicides, herbicides and insecticides throughout the watershed. Concentration ranges revealed little spatio-temporal variation. From an ecotoxicological point of view, the insecticide levels – notably chlorpyrifos and cypermethrin - were most critical. The observed concentration levels exceeded chronic environmental quality standards more than 100-fold at all sites. These high insecticide levels were partially reflected in the community composition of the macroinvertebrates. Available data revealed a poor status at two upstream locations according to the Costa Rican Biological Monitoring Working Party (BMWP-CR) Index and the SPEARpesticides index. However, the indices indicated a good quality at most downstream sites despite their high pesticide levels. The wide-spread occurrence of high pesticide levels demonstrated that the relevant sources and pathways existed throughout the catchment. Field observations and survey data showed the relevance of point sources due to poor pesticide handling as well as diffuse losses from fields, which are strongly enhanced by the steep terrain and linear structures like gullies connecting fields with the stream. Mitigation measures to reduce pesticide losses have to account for these different source-flowpath combinations.http://www.sciencedirect.com/science/article/pii/S2666765722001740Small-holder farmingHorticulturePassive samplingBMWP-CRSPEAR index |
| spellingShingle | Frederik T. Weiss Clemens Ruepert Silvia Echeverría-Sáenz Rik I.L. Eggen Christian Stamm Agricultural pesticides pose a continuous ecotoxicological risk to aquatic organisms in a tropical horticulture catchment Environmental Advances Small-holder farming Horticulture Passive sampling BMWP-CR SPEAR index |
| title | Agricultural pesticides pose a continuous ecotoxicological risk to aquatic organisms in a tropical horticulture catchment |
| title_full | Agricultural pesticides pose a continuous ecotoxicological risk to aquatic organisms in a tropical horticulture catchment |
| title_fullStr | Agricultural pesticides pose a continuous ecotoxicological risk to aquatic organisms in a tropical horticulture catchment |
| title_full_unstemmed | Agricultural pesticides pose a continuous ecotoxicological risk to aquatic organisms in a tropical horticulture catchment |
| title_short | Agricultural pesticides pose a continuous ecotoxicological risk to aquatic organisms in a tropical horticulture catchment |
| title_sort | agricultural pesticides pose a continuous ecotoxicological risk to aquatic organisms in a tropical horticulture catchment |
| topic | Small-holder farming Horticulture Passive sampling BMWP-CR SPEAR index |
| url | http://www.sciencedirect.com/science/article/pii/S2666765722001740 |
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