U.S. Geological Survey , Fort Collins Science Center, 2150 Centre Avenue, Bldg. C, Fort Collins, Colorado 80526, United States.
U.S. Geological Survey , Colorado Water Science Center, Lakewood, Colorado 80225, United States.
Environ Sci Technol. 2016 Nov 1;50(21):11974-11983. doi: 10.1021/acs.est.6b02761. Epub 2016 Oct 12.
Direct and indirect ecological effects of the widely used insecticide bifenthrin on stream ecosystems are largely unknown. To investigate such effects, a manipulative experiment was conducted in stream mesocosms that were colonized by aquatic insect communities and exposed to bifenthrin-contaminated sediment; implications for natural streams were interpreted through comparison of mesocosm results to a survey of 100 Midwestern streams, USA. In the mesocosm experiment, direct effects of bifenthrin exposure included reduced larval macroinvertebrate abundance, richness, and biomass at concentrations (EC's ranged from 197.6 to 233.5 ng bifenthrin/g organic carbon) previously thought safe for aquatic life. Indirect effects included a trophic cascade in which periphyton abundance increased after macroinvertebrate scrapers decreased. Adult emergence dynamics and corresponding terrestrial subsidies were altered at all bifenthrin concentrations tested. Extrapolating these results to the Midwestern stream assessment suggests pervasive ecological effects, with altered emergence dynamics likely in 40% of streams and a trophic cascade in 7% of streams. This study provides new evidence that a common pyrethroid might alter aquatic and terrestrial ecosystem function at the regional scale.
广泛使用的杀虫剂联苯菊酯对溪流生态系统的直接和间接生态影响在很大程度上是未知的。为了研究这些影响，在溪流中进行了一项操纵实验，这些溪流被水生昆虫群落殖民，并暴露于受联苯菊酯污染的沉积物中；通过将中观实验结果与对美国中西部 100 条溪流的调查进行比较，解释了其对自然溪流的影响。在中观实验中，联苯菊酯暴露的直接影响包括在先前被认为对水生生物安全的浓度（EC 值范围为 197.6 至 233.5ng 联苯菊酯/克有机碳）下，幼虫大型无脊椎动物的丰度、丰富度和生物量减少。间接影响包括食草动物减少后，周丛藻类丰度增加的营养级联。在测试的所有联苯菊酯浓度下，成虫的出现动态及其相应的陆地补充都发生了变化。将这些结果外推到中西部溪流评估中表明存在普遍的生态影响，40%的溪流中出现了成虫出现动态的变化，7%的溪流中出现了营养级联。本研究提供了新的证据，表明一种常见的拟除虫菊酯可能会改变水生和陆地生态系统在区域尺度上的功能。
