Pomati Francesco, Jokela Jukka, Castiglioni Sara, Thomas Mridul K, Nizzetto Luca
Eawag: Swiss Federal Institute of Water Science and Technology, Dübendorf, Switzerland.
ETH Zurich, Institute for Integrative Biology, Dübendorf, Switzerland.
PLoS One. 2017 Mar 22;12(3):e0174207. doi: 10.1371/journal.pone.0174207. eCollection 2017.
Chemical micropollutants occur worldwide in the environment at low concentrations and in complex mixtures, and how they affect the ecology of natural systems is still uncertain. Dynamics of natural communities are driven by the interaction between individual organisms and their growth environment, which is mediated by the organisms' expressed phenotypic traits. We tested whether exposure to a mixture of 12 pharmaceuticals and personal care products (PPCP) influences phenotypic trait diversity in lake phytoplankton communities and their ability to regulate biomass production to fit environmental changes (response capacity). We exposed natural phytoplankton assemblages to three mixture levels in permeable microcosms maintained at three depths in a eutrophic lake for one week, during which the environmental conditions were fluctuating. We studied individual-level traits, phenotypic diversity and community biomass. PPCP reduced individual-level trait variance and overall community phenotypic diversity, but maintained higher standing phytoplankton biomass compared to untreated controls. Estimated effect sizes of PPCP on traits and community properties were very large (partial Eta-squared > 0.15). The PPCP mixture antagonistically interacted with the natural environmental gradient in habitats offered by different depths and, at concentrations comparable to those in waste-water effluents, prevented communities from converging to the same phenotypic structure and total biomass of unexposed controls. We show that micropollutants can alter individual-level trait diversity of lake phytoplankton communities and therefore their capacity to respond to natural environmental gradients, potentially affecting aquatic ecosystem processes.
化学微污染物以低浓度且呈复杂混合物的形式存在于全球环境中，它们如何影响自然系统的生态仍不确定。自然群落的动态受个体生物与其生长环境之间相互作用的驱动，这种相互作用由生物所表现出的表型特征介导。我们测试了暴露于12种药物和个人护理产品（PPCP）的混合物中是否会影响湖泊浮游植物群落的表型特征多样性及其调节生物量生产以适应环境变化的能力（响应能力）。我们将天然浮游植物组合暴露于富营养化湖泊中三个深度处维持的可渗透微观环境中的三种混合物水平下一周，在此期间环境条件波动。我们研究了个体水平的特征、表型多样性和群落生物量。与未处理的对照相比，PPCP降低了个体水平的特征方差和整个群落的表型多样性，但维持了更高的浮游植物现存量。PPCP对特征和群落特性的估计效应大小非常大（偏 eta 平方>0.15）。PPCP混合物与不同深度提供的栖息地中的自然环境梯度产生拮抗相互作用，并且在与废水排放物中浓度相当的情况下，阻止群落收敛到未暴露对照的相同表型结构和总生物量。我们表明，微污染物可以改变湖泊浮游植物群落的个体水平特征多样性，从而改变它们对自然环境梯度的响应能力，这可能会影响水生生态系统过程。
