Gene-to-ecosystem impacts of a catastrophic pesticide spill: testing a multilevel bioassessment approach in a river ecosystem
Gene-to-ecosystem impacts of a catastrophic pesticide spill: testing a multilevel bioassessment approach in a river ecosystem
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DOI：
10.1111/fwb.12676
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发表时间：
2016-12
影响因子：
2.7
通讯作者：
M. Thompson;M. Thompson;C. Bankier;T. Bell;A. Dumbrell;Clare Gray;Clare Gray;M. Ledger;Katja Leh
中科院分区：
文献类型：
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作者：
M. Thompson;M. Thompson;C. Bankier;T. Bell;A. Dumbrell;Clare Gray;Clare Gray;M. Ledger;Katja Leh
1.农药在淡水沃茨中可能产生强烈的有害影响，但了解这些影响如何通过自然生态系统，从微生物到顶级捕食者，是有限的，因为跨越多个层次的生物组织的研究是罕见的。2.我们报告了一次意外的杀虫剂泄漏如何改变了从基因到生态系统的河流结构和功能。我们量化了对微生物，硅藻，大型无脊椎动物和鱼类的组合的影响，并测量了泄漏后2个月上游控制和下游受影响地点的落叶分解率和微生物功能潜力。3.直接和间接的影响都很明显，在多个层次的组织和类群，从食物网的基础更高的营养级。在分子水平上，受影响地点内功能基因丰度的差异反映了农药的直接和间接影响的结合，通过提高能够利用毒死蜱作为资源的微生物种群的丰度（即直接影响）和腐烂的大型无脊椎动物尸体释放的氧化氨（即间接影响）。4.在食物链的基础上，硅藻类群发现只有在受影响的网站是一个数量级的细胞大小比最大的可比类群在控制社区，其消费者几乎灭绝。关键食蟹动物钩虾的种群生物量明显降低，凋落物分解率也明显降低。然而，这部分地被微生物分解的增加所补偿，这表明有毒物质泄漏的另一种间接食物网效应。5.虽然许多物种出现种群崩溃或局部灭绝，但大型无脊椎动物总生物量和丰度基本上未受影响，这是由于小型耐受类群（如寡毛类）和/或在溢出时处于成虫空中生命阶段的类群（如摇蚊）补偿性升高，从而避免与污染的沃茨接触，并能够迅速在河流中重新繁殖。消费者和资源之间的营养联系的质量丰度缩放揭示了广泛的重组内的食物网。6.该案例研究表明，农药可以直接和间接地影响食物网结构和生态系统功能。它还表明，这里采用的综合评估方法如何能够阐明微生物群、大型无脊椎动物和鱼类之间的联系，从而提高我们对自然生态系统中化学污染的各种生物后果的认识。
1. Pesticides can have strong deleterious impacts in fresh waters, but understanding how these effects cascade through natural ecosystems, from microbes to apex predators, is limited because research that spans multiple levels of biological organisation is rare. 2. We report how an accidental insecticide spill altered the structure and functioning of a river across levels ranging from genes to ecosystems. We quantified the impacts on assemblages of microbes, diatoms, macroinvertebrates and fish and measured leaf-litter decomposition rates and microbial functional potential at upstream control and downstream impacted sites 2 months after the spill. 3. Both direct and indirect impacts were evident across multiple levels of organisation and taxa, from the base of the food web to higher trophic levels. At the molecular level, differences in functional gene abundance within the impacted sites reflected a combination of direct and indirect effects of the pesticide, via elevated abundances of microbial populations capable of using chlorpyrifos as a resource (i.e. direct effect) and oxidising ammonia released by decaying macroinvertebrate carcasses (i.e. indirect effect). 4. At the base of the food chains, diatom taxa found only in the impacted sites were an order-of- magnitude larger in cell size than the largest comparable taxa in control communities, following the near extirpation of their consumers. Population biomass of the key detritivore Gammarus pulex was markedly lower, as was the rate of litter decomposition in the impacted sites. This was partially compensated for, however, by elevated microbial breakdown, suggesting another indirect food-web effect of the toxic spill. 5. Although many species exhibited population crashes or local extirpation, total macroinvertebrate biomass and abundance were largely unaffected due to a compensatory elevation in small tolerant taxa such as oligochaetes, and/or taxa which were in their adult aerial life stage at the time of the spill (e.g. chironomids) and thus avoided contact with the polluted waters and were able to repopu- late the river quickly. Mass–abundance scaling of trophic links between consumers and resources revealed extensive restructuring within the food web. 6. This case study shows that pesticides can affect food-web structure and ecosystem functioning, both directly and indirectly across levels of biological organisation. It also demonstrates how an integrated assessment approach, as adopted here, can elucidate links between microbiota, macroinvertebrates and fish, for instance, thus improving our understanding of the range of biological consequences of chemical contamination in natural ecosystems.