Van den Brink Paul J, Klein Sylvan L, Rico Andreu
Department of Aquatic Ecology and Water Quality Management, Wageningen University and Research Centre, Wageningen University, Wageningen, The Netherlands.
Alterra, Wageningen University and Research Centre, Wageningen, The Netherlands.
Environ Toxicol Chem. 2017 Sep;36(9):2485-2492. doi: 10.1002/etc.3788. Epub 2017 Apr 4.
The present study investigated the effects of species interactions like competition and (intraguild) predation on the sensitivity of aquatic organisms to the insecticide chlorpyrifos. In the first experiment, combined effects of chlorpyrifos and different levels of intraspecific and interspecific interaction were assessed on Gammarus pulex survival using Asellus aquaticus as an interacting species. Intraspecific and interspecific interactions increased the time to extinction of G. pulex up to a factor of 2, most likely because of the cannibalistic nature of G. pulex and its intraguild predation on A. aquaticus under stress conditions. In the second experiment, combined effects of chlorpyrifos and intraspecific and interspecific interaction were assessed on Daphnia pulex abundance using Brachionus calyciflorus as a competing species and Chaoborus sp. larvae as a predator. Intraspecific and interspecific interactions significantly affected the D. pulex population structure, but they did not influence the total population size. Predation decimated D. pulex abundance; however, interacting effects of predation and chlorpyrifos exposure were less noticeable at high exposure concentrations because of the reduced predatory efficiency of Chaoborus sp. larvae. The present study shows that species interactions do not always increase the vulnerability of aquatic populations to chemical stress and that some interactions (e.g., cannibalism and intraguild predation) or reduced predator grazing pressure can alleviate competition and predation stress on population-level insecticide effects under food-limiting conditions. Environ Toxicol Chem 2017;36:2485-2492. © 2017 SETAC.
本研究调查了竞争和（集团内）捕食等物种相互作用对水生生物对杀虫剂毒死蜱敏感性的影响。在第一个实验中，以水虱作为相互作用物种，评估了毒死蜱与不同水平的种内和种间相互作用对蚤状钩虾存活的综合影响。种内和种间相互作用将蚤状钩虾的灭绝时间延长了两倍，这很可能是由于蚤状钩虾的同类相食特性及其在应激条件下对水虱的集团内捕食行为。在第二个实验中，以萼花臂尾轮虫作为竞争物种，以摇蚊幼虫作为捕食者，评估了毒死蜱与种内和种间相互作用对大型溞丰度的综合影响。种内和种间相互作用显著影响了大型溞的种群结构，但并未影响其种群总数。捕食行为使大型溞的丰度大幅下降；然而，由于摇蚊幼虫的捕食效率降低，在高暴露浓度下，捕食与毒死蜱暴露的相互作用不太明显。本研究表明，物种相互作用并不总是会增加水生种群对化学胁迫的脆弱性，并且某些相互作用（如同类相食和集团内捕食）或捕食压力的降低可以在食物限制条件下减轻种群水平上杀虫剂效应的竞争和捕食压力。《环境毒理学与化学》2017年；36:2485 - 2492。© 2017 SETAC。
