Bray Jonathan P, O'Reilly-Nugent Andrew, Kon Kam King Guillaume, Kaserzon Sarit, Nichols Susan J, Nally Ralph Mac, Thompson Ross M, Kefford Ben J
Centre for Applied Water Science, Institute for Applied Ecology, University of Canberra, Canberra, Australia.
Centre for Applied Water Science, Institute for Applied Ecology, University of Canberra, Canberra, Australia.
Sci Total Environ. 2021 Apr 1;763:142997. doi: 10.1016/j.scitotenv.2020.142997. Epub 2020 Oct 17.
Pesticides are increasingly recognised as a threat to freshwater biodiversity, but their specific ecological effects remain difficult to distinguish from those of co-occurring stressors and environmental gradients. Using mesocosms we examined the effects of an organophosphate insecticide (malathion) on stream macroinvertebrate communities concurrently exposed to a suite of stressors typical of streams in agricultural catchments. We assessed the specificity of the SPEcies At Risk index designed to determine pesticide effects in mesocosm trials (SPEAR). This index determines the log abundance proportion of taxa that are considered physiologically sensitive to pesticides. Geographic variation in pesticide sensitivity within taxa, coupled with variation between pesticides and the effects of co-occurring stressors may decrease the accuracy of SPEAR. To examine this, we used local pesticide sensitivity assessments based on rapid toxicity tests to develop two new SPEAR versions to compare to the original SPEAR index using mesocosm results. We further compared these results to multivariate analyses and community indices (e.g. richness, abundance, Simpson's diversity) commonly used to assess stressor effects on biota. To assess the implications of misclassifying species sensitivity on SPEAR indices we used a series of simulations using artificial data. The impacts of malathion were detectable using SPEAR, and one of two new SPEAR indices. All three of the SPEAR indices also increased when exposed to other agricultural non-pesticide stressors, and this change increased with greater pesticide concentrations. Our results support that interactions between other non-pesticide stressors with pesticides can affect SPEAR performance. Multivariate analysis and the other indices used here identified a significant effect of malathion especially at high concentrations, with little or no evidence of effects from the other agricultural stressors.
农药日益被视为对淡水生物多样性的一种威胁，但其具体的生态影响仍难以与同时存在的压力源和环境梯度的影响区分开来。我们利用中型生态系统研究了一种有机磷杀虫剂（马拉硫磷）对溪流大型无脊椎动物群落的影响，这些群落同时受到农业集水区溪流典型的一系列压力源的影响。我们评估了旨在确定中型生态系统试验中农药影响的濒危物种指数（SPEAR）的特异性。该指数确定了被认为对农药生理敏感的分类单元的对数丰度比例。分类单元内农药敏感性的地理差异，再加上不同农药之间的差异以及同时存在的压力源的影响，可能会降低SPEAR的准确性。为了研究这一点，我们基于快速毒性试验进行了本地农药敏感性评估，以开发两个新的SPEAR版本，并将其与使用中型生态系统结果的原始SPEAR指数进行比较。我们进一步将这些结果与通常用于评估压力源对生物群影响的多变量分析和群落指数（如丰富度、丰度、辛普森多样性）进行比较。为了评估将物种敏感性误分类对SPEAR指数的影响，我们使用人工数据进行了一系列模拟。使用SPEAR和两个新的SPEAR指数之一可以检测到马拉硫磷的影响。当暴露于其他农业非农药压力源时，所有三个SPEAR指数也会增加，并且这种变化随着农药浓度的增加而增大。我们的结果支持其他非农药压力源与农药之间的相互作用会影响SPEAR的性能。多变量分析和这里使用的其他指数确定了马拉硫磷的显著影响，尤其是在高浓度时，几乎没有或没有证据表明其他农业压力源有影响。
Zotero 插件