Laboratory of Environmental Toxicology and Aquatic Ecology, Environmental Toxicology Unit, Ghent University, Gent, Belgium.
Wageningen Environmental Research, Wageningen, The Netherlands.
Environ Toxicol Chem. 2018 Sep;37(9):2413-2427. doi: 10.1002/etc.4201. Epub 2018 Jul 23.
Ecotoxicological studies mainly consist of single-species experiments evaluating the effects of a single stressor. However, under natural conditions aquatic communities are exposed to a mixture of stressors. The present study aimed to identify how the toxicity of zinc (Zn) is affected by increased temperature and increased phosphorus (P) supply and how these interactions vary among species, functional groups, and community structure and function. Aquatic microcosms were subjected to 3 Zn concentrations (background, no Zn added, and 75 and 300 μg Zn/L), 2 temperatures (16-19 and 21-24 °C), and 2 different P additions (low, 0.02, and high, 0.4 mg P L wk ) for 5 wk using a full factorial design. During the study, consistent interactions between Zn and temperature were only rarely found at the species level (4%), but were frequently found at the functional group level (36%), for community structure (100%) and for community function (100%; such as dissolved organic carbon concentrations and total chlorophyll). The majority of the Zn × temperature interactions were observed at 300 μg Zn/L and generally indicated a smaller effect of Zn at higher temperature. Furthermore, no clear indication was found that high P addition by itself significantly affected the overall effects of Zn on the community at any level of organization. Interestingly, though, 90% of all the Zn × temperature interactions observed at the species, group, and community composition level were found under high P addition. Collectively, the results of our study with the model chemical Zn suggest that temperature and phosphorus loading to freshwater systems should be accounted for in risk assessment, because these factors may modify the effects of chemicals on the structure and functioning of aquatic communities, especially at higher levels of biological organization. Environ Toxicol Chem 2018;37:2413-2427. © 2018 SETAC.
生态毒理学研究主要包括评估单一胁迫因素对单一物种影响的实验。然而，在自然条件下，水生群落受到多种胁迫因素的混合影响。本研究旨在确定在增加温度和增加磷供应的情况下，锌（Zn）的毒性如何受到影响，以及这些相互作用如何因物种、功能群以及群落结构和功能而变化。使用完全因子设计，将水生微宇宙暴露于 3 种 Zn 浓度（背景、未添加 Zn 以及 75 和 300μg Zn/L）、2 种温度（16-19 和 21-24°C）和 2 种不同磷添加（低，0.02 和高，0.4mg P L wk ）下 5 周。在研究过程中，仅在物种水平（4%）很少发现 Zn 和温度之间的一致相互作用，但在功能群水平（36%）、群落结构（100%）和群落功能（100%；如溶解有机碳浓度和总叶绿素）中经常发现。大多数 Zn×温度相互作用发生在 300μg Zn/L，一般表明 Zn 在较高温度下的影响较小。此外，没有明显的迹象表明高磷添加本身会在任何组织水平上显著影响 Zn 对群落的整体影响。有趣的是，尽管如此，在物种、组和群落组成水平上观察到的所有 Zn×温度相互作用中有 90%是在高磷添加下发现的。总的来说，本研究使用模型化学 Zn 的结果表明，在淡水系统中，温度和磷负荷应纳入风险评估，因为这些因素可能会改变化学物质对水生群落结构和功能的影响，特别是在较高的生物组织水平上。Environ Toxicol Chem 2018;37:2413-2427. © 2018 SETAC.
