Toxicology Centre, University of Saskatchewan, Saskatoon, Saskatchewan, Canada.
Toxicology Centre, University of Saskatchewan, Saskatoon, Saskatchewan, Canada; School of Environment and Sustainability, University of Saskatchewan, Saskatoon, Saskatchewan, Canada.
Environ Pollut. 2021 Jul 1;280:116956. doi: 10.1016/j.envpol.2021.116956. Epub 2021 Mar 17.
Selenium (Se) is both an essential micronutrient and a contaminant of concern that is of particular interest in mining-influenced waterbodies in Canada. The objective of this research was to characterize the trophic dynamics of selenium along a gradient of exposure concentrations in a Canadian boreal lake ecosystem. From June 20 to August 22, 2018, six limnocorrals (littoral, ∼3000 L enclosures) were spiked with mean measured concentrations of 0.4, 0.8, 1.6, 3.4, 5.6 and 7.9 μg Se/L as selenite, and three limnocorrals served as untreated controls (background aqueous Se = 0.08-0.09 μg/L). Total Se (TSe) concentrations in water, periphyton, phytoplankton, sediment, benthic macroinvertebrates, zooplankton and female finescale dace (Phoxinus neogaeus; added on day 21 of the experiment) were measured throughout and at the end of the experiment. Total Se bioaccumulation by organisms was generally non-linear. Greater uptake by phytoplankton than periphyton was observed. Taxonomic differences in accumulation of TSe by invertebrates (Heptageniidae = Chironomidae > zooplankton) were observed as well. Fish muscle and ovary tissue TSe bioaccumulation was more variable than that at lower trophic levels and uptake patterns indicated that fish did not reach steady state concentrations. This research provides field-derived models for the uptake of Se by algae and invertebrates, and contributes to a better understanding of the dynamics of TSe bioaccumulation over a gradient of exposure concentrations in cold-water lentic systems.
硒（Se）既是一种必需的微量元素，也是一种值得关注的污染物，在加拿大受采矿影响的水体中尤其受到关注。本研究的目的是描述加拿大北方湖泊生态系统中硒在暴露浓度梯度上的营养动态。2018 年 6 月 20 日至 8 月 22 日，6 个 Limnocorrals（沿岸，约 3000 L 围场）被注入平均实测浓度为 0.4、0.8、1.6、3.4、5.6 和 7.9μg/L 的亚硒酸盐，3 个 Limnocorrals 作为未处理的对照（背景水硒=0.08-0.09μg/L）。在整个实验过程中和实验结束时，测量了水中、附生生物、浮游植物、沉积物、底栖大型无脊椎动物、浮游动物和雌性细纹鱲（Phoxinus neogaeus；在实验的第 21 天添加）的总硒（TSe）浓度。生物体内总硒的生物积累通常是非线性的。观察到浮游植物比附生生物的吸收量更大。无脊椎动物对 TSe 的积累也存在分类差异（Heptageniidae>Chironomidae>浮游动物）。鱼类肌肉和卵巢组织的 TSe 生物积累比低营养水平更具变异性，吸收模式表明鱼类尚未达到稳定状态浓度。本研究提供了藻类和无脊椎动物对 Se 吸收的现场衍生模型，并有助于更好地了解冷水湖泊系统中暴露浓度梯度上 TSe 生物积累的动态。
