Nutrients and sediment modify the impacts of a neonicotinoid insecticide on freshwater community structure and ecosystem functioning.

Autor: Chará-Serna AM; Department of Forest and Conservation Sciences, University of British Columbia, 2424 Main Mall, Vancouver, BC V6T 1Z4, Canada; Centro para la Investigación en Sistemas Sostenibles de Producción Agropecuaria (CIPAV), Carrera 25 No. 6-62, Cali, Colombia. Electronic address: ana@fun.cipav.org.co., Epele LB; Centro de Investigación Esquel de Montaña y Estepa Patagónica (CONICET-UNPSJB), Roca 780, Esquel, Chubut, Argentina., Morrissey CA; Department of Biology and School of Environment and Sustainability, University of Saskatchewan, 112 Science Place, Saskatoon, Saskatchewan, Canada., Richardson JS; Department of Forest and Conservation Sciences, University of British Columbia, 2424 Main Mall, Vancouver, BC V6T 1Z4, Canada.
Jazyk: angličtina
Zdroj: The Science of the total environment [Sci Total Environ] 2019 Nov 20; Vol. 692, pp. 1291-1303. Date of Electronic Publication: 2019 Jul 11.
DOI: 10.1016/j.scitotenv.2019.06.301
Abstrakt: Pesticides are important contributors to the global freshwater biodiversity crisis. Among pesticides, neonicotinoids are the best-selling class of agricultural insecticides and are suspected to represent significant risks to freshwater and terrestrial ecosystems worldwide. Despite growing recognition that neonicotinoid impacts may be modified by the presence of additional stressors, there is limited information about their interactions with other agricultural stressors in freshwater ecosystems. We conducted an outdoor pond-mesocosm experiment to investigate the individual and interactive effects of nutrients, fine sediment, and imidacloprid (a neonicotinoid insecticide) inputs on freshwater community structure (density, diversity, and composition of zooplankton and benthic invertebrates) and ecosystem functioning (ecosystem metabolism, primary production, and organic matter decomposition). We hypothesized antagonistic nutrient-imidacloprid, and synergistic sediment-imidacloprid interactions, affecting aquatic invertebrate communities. The three stressors had significant individual and interactive effects on pond ecosystems. The insecticide neutralized the positive effects of nutrient additions on benthic invertebrate richness and mitigated the negative effects of sediment on zooplankton communities (antagonistic interactions). Moreover, we observed compensatory responses of tolerant benthic invertebrates, which resulted in reversal interactions between sediment and imidacloprid. Furthermore, our observations suggest that imidacloprid has the potential to increase net ecosystem production at environmentally relevant concentrations. Our findings support the hypothesis that the impacts of imidacloprid may be modified by other agricultural stressors. This has important implications on a global scale, given the widespread use of these pesticides in intensive agricultural landscapes and the growing body of literature suggesting that traditional pesticide assessment frameworks, based on laboratory toxicity tests alone, may be insufficient to adequately predict effects to complex freshwater ecosystems.
(Copyright © 2019 Elsevier B.V. All rights reserved.)
Databáze: MEDLINE
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