Smedbol Élise, Gomes Marcelo Pedrosa, Paquet Serge, Labrecque Michel, Lepage Laurent, Lucotte Marc, Juneau Philippe
Université du Québec à Montréal, Département des Sciences Biologiques - GRIL - TOXEN, Laboratory of Aquatic Microorganism Ecotoxicology, Succ. Centre-Ville, C.P. 8888, H3C 3P8, Montréal, Québec, Canada; Université du Québec à Montréal, Institut des Sciences de l'environnement & GEOTOP, Succ. Centre-Ville, C.P. 8888, H3C 3P8, Montréal, Québec, Canada.
Université du Québec à Montréal, Département des Sciences Biologiques - GRIL - TOXEN, Laboratory of Aquatic Microorganism Ecotoxicology, Succ. Centre-Ville, C.P. 8888, H3C 3P8, Montréal, Québec, Canada; Universidade Federal de Minas Gerais, Instituto de Ciências Biológicas, Departamento de Botânica, Avenida Antônio Carlos, 6627, Pampulha, Caixa Postal 486, 31270-970, Belo Horizonte, Minas Gerais, Brazil.
Chemosphere. 2018 Feb;192:133-141. doi: 10.1016/j.chemosphere.2017.10.128. Epub 2017 Nov 14.
Residual glyphosate from glyphosate based herbicides (GBH) are ubiquitously detected in streams draining agricultural fields, and may affect phytoplankton communities present in these ecosystems. Here, the effects of the exposure (96 h) of a phytoplankton community collected in an agricultural stream to various glyphosate concentrations (1, 5, 10, 50, 100, 500 and 1000 μg l) of Factor 540 GBH were investigated. The lowest GBH concentration of 1 μg l reduced chlorophyll a and carotenoid contents. Low glyphosate concentrations, such as 5 and 10 μg l, promoted changes in the community's structure and reduced the diversity of the main algal species. At glyphosate concentrations ranging from 50 to 1000 μg l, the phytoplankton community's composition was modified and new main species appeared. The highest glyphosate concentrations (500 and 1000 μg l) affected the shikimate content, the lipid peroxidation and the activity of antioxidant enzymes (superoxide dismutase, catalase and ascorbate peroxidase). These results indicate that GBH can modify structural and functional properties of freshwater phytoplankton communities living in streams located in agricultural areas at glyphosate concentrations much inferior to the 800 μg l threshold set by the Canadian guidelines for the protection of aquatic life.
在流经农田的溪流中普遍检测到草甘膦基除草剂（GBH）残留的草甘膦，其可能会影响这些生态系统中的浮游植物群落。在此，研究了从一条农业溪流中采集的浮游植物群落暴露于不同浓度（1、5、10、50、100、500和1000μg/l）的540因子GBH 96小时后的影响。最低GBH浓度1μg/l降低了叶绿素a和类胡萝卜素含量。低浓度草甘膦，如5和10μg/l，促使群落结构发生变化，并降低了主要藻类物种的多样性。在草甘膦浓度为50至1000μg/l范围内，浮游植物群落组成发生改变，出现了新的主要物种。最高草甘膦浓度（500和1000μg/l）影响莽草酸含量、脂质过氧化以及抗氧化酶（超氧化物歧化酶、过氧化氢酶和抗坏血酸过氧化物酶）的活性。这些结果表明，GBH能够改变农业区溪流中淡水浮游植物群落的结构和功能特性，而所需的草甘膦浓度远低于加拿大水生生物保护指南设定的800μg/l阈值。
