Toxicology Centre, University of Saskatchewan, Saskatoon, SK, Canada.
Toxicology Centre, University of Saskatchewan, Saskatoon, SK, Canada; School of Environment and Sustainability, University of Saskatchewan, Saskatoon, SK, Canada.
Environ Res. 2023 Oct 1;234:116157. doi: 10.1016/j.envres.2023.116157. Epub 2023 May 16.
Few studies have investigated the potential influence of sampling method and season on Se bioaccumulation at the base of the aquatic food chain. In particular, the effects of low water temperature associated with prolonged ice-cover periods on Se uptake by periphyton and further transfer to benthic macroinvertebrates (BMI) have been overlooked. Such information is crucial to help improve Se modelling and risk assessment at sites receiving continuous Se inputs. To date, this seems to be the first study to address these research questions. Here, we examined potential differences related to sampling methods (artificial substrates vs. grab samples) and seasons (summer vs. winter) on Se dynamics in the benthic food chain of a boreal lake (McClean Lake) receiving continuous low-level Se input from a Saskatchewan uranium milling operation. During summer 2019, water, sediment grab samples and artificial substrates were sampled from 8 sites with varying mill-treated effluent exposure. In winter 2021, water and sediment grab samples were sampled at 4 locations in McClean Lake. Water, sediment, and biological samples were subsequently analyzed for total Se concentrations. Enrichment functions (EF) in periphyton and trophic transfer factors (TTF) in BMI were calculated for both sampling methods and seasons. Periphyton collected with artificial substrates (Hester-Dendy samplers and glass plates) exhibited significantly higher mean Se concentrations (2.4 ± 1.5 μg/g d.w) than periphyton collected from the surface of sediment grab samples (1.1 ± 1.3 μg/g d.w). Selenium concentrations in periphyton sampled in winter (3.5 ± 1.0 μg/g d.w) were significantly greater than summer (1.1 ± 1.3 μg/g d.w). Nevertheless, Se bioaccumulation in BMI was similar between seasons, possibly suggesting that invertebrates are not actively feeding in winter. Further investigations are necessary to verify if peak Se bioaccumulation in BMI takes place in spring, coinciding with the reproductive and developmental windows of some fish species.
很少有研究调查采样方法和季节对水生食物链底部硒生物积累的潜在影响。特别是，与长时间冰盖期相关的低温对底栖生物（附着生物和底栖大型无脊椎动物）中硒吸收及其进一步向底栖大型无脊椎动物转移的影响一直被忽视。这些信息对于帮助改善连续接受硒输入的地点的硒建模和风险评估至关重要。迄今为止，这似乎是第一项解决这些研究问题的研究。在这里，我们研究了与采样方法（人工基质与抓斗样本）和季节（夏季与冬季）相关的潜在差异，这些差异与接收萨斯喀彻温省铀矿加工操作连续低水平硒输入的北方湖泊（McClean Lake）的底栖食物链中的硒动态有关。在 2019 年夏季，从 8 个具有不同处理过的废水暴露程度的地点采集水样、沉积物抓斗样本和人工基质。在 2021 年冬季，在 McClean Lake 的 4 个地点采集水样和沉积物抓斗样本。随后对水样、沉积物和生物样本进行总硒浓度分析。为两种采样方法和两个季节计算了附着生物中的富集函数（EF）和底栖大型无脊椎动物中的营养转移因子（TTF）。用人工基质（Hester-Dendy 采样器和玻璃片）采集的附着生物的硒浓度（2.4±1.5μg/g dw）明显高于从沉积物抓斗样本表面采集的附着生物的硒浓度（1.1±1.3μg/g dw）。冬季采集的附着生物的硒浓度（3.5±1.0μg/g dw）明显高于夏季（1.1±1.3μg/g dw）。尽管如此，底栖大型无脊椎动物中的硒生物积累在两个季节之间相似，这可能表明无脊椎动物在冬季没有积极进食。需要进一步调查以验证底栖大型无脊椎动物中的硒生物积累是否在春季达到峰值，此时与一些鱼类物种的繁殖和发育窗口相吻合。
