Kelly Madison R, Cohen Risa A
Department of Biology, Georgia Southern University, PO Box 8042-1, Statesboro, GA, 30460, USA.
Bull Environ Contam Toxicol. 2018 Nov;101(5):556-561. doi: 10.1007/s00128-018-2451-0. Epub 2018 Sep 22.
Widespread use of agrochemicals increases their likelihood of entering aquatic systems in mixture. Despite different modes of action, atrazine (herbicide) and tetracycline (antibiotic) adversely affect non-target photosynthetic organisms individually, but the effects of simultaneous exposure to both contaminants are untested. We created microcosms containing microalgae (Chlorella sp.), floating macrophytes (Lemna minor), and a zooplankton grazer (Daphnia magna). Microcosms were exposed to environmentally relevant concentrations of atrazine and tetracycline, alone and together, for 10 days. Atrazine decreased Chlorella sp. abundance, but not enough to reduce food availability to D. magna whose reproduction and mortality were unaffected. In contrast, tetracycline and atrazine appeared to have additive effects on L. minor abundance and growth inhibition. These additive adverse effects suggest increased potential for L. minor population decline over the long term, and potential for altered species interactions in aquatic systems receiving agricultural runoff.
农用化学品的广泛使用增加了它们以混合物形式进入水生系统的可能性。尽管作用方式不同，但阿特拉津（除草剂）和四环素（抗生素）分别对非目标光合生物有不利影响，但同时暴露于这两种污染物的影响尚未得到测试。我们创建了含有微藻（小球藻属）、漂浮大型植物（浮萍）和浮游动物食草动物（大型溞）的微型生态系统。微型生态系统分别单独和同时暴露于环境相关浓度的阿特拉津和四环素中，持续10天。阿特拉津降低了小球藻属的丰度，但不足以减少大型溞的食物供应，大型溞的繁殖和死亡率未受影响。相比之下，四环素和阿特拉津似乎对浮萍的丰度和生长抑制有相加作用。这些相加的不利影响表明，从长期来看，浮萍种群数量下降的可能性增加，并且在接受农业径流的水生系统中，物种相互作用可能发生改变。
