Environment and Life Sciences Research Center, Kuwait Institute for Scientific Research, P.O. Box 24885, Safat 13109, Kuwait.
Environment and Life Sciences Research Center, Kuwait Institute for Scientific Research, P.O. Box 24885, Safat 13109, Kuwait.
Mar Pollut Bull. 2020 Feb;151:110844. doi: 10.1016/j.marpolbul.2019.110844. Epub 2020 Jan 29.
Climate change effects such as ocean acidification (OA) are known to affect the trace metal distribution. This experimental study provides the first data on Po uptake rates and Po concentration in five microalgae species under different pH scenarios. The experiment was conducted in replicates at three pH conditions 8.2, 8.0, and 7.5, representing the current and future climate change scenario as per IPCC RCP8.5. The Po uptake in the phytoplankton was highest in Thalassiosira weissflogi, i.e. 83% of the Po tracer was taken up at 8.2 pH whereas the lowest uptake was observed in Dunaliella salina equivalent to 20% at 7.5 pH. Similar behavior was observed in Po concentrations in these microalgae, where Po ranged between 3.16 ± 0.03 and 11.6 ± 0.04 Bq kg wet weight (ww), with the highest in the Thalassioria weissflogi at 8.2 pH, and the lowest in Dunaliella salina at 7.5 pH. The difference in Po uptake and Po concentration was statistically significant (p < 0.001) both among species and the pH treatments in the order: Thalassiosira weissflogi > Tetraselmis suecica > Chaetoceros muelleri > Isochrysis galbana > Dunaliella salina and 8.2 > 8.0 > 7.5. A higher concentration of Po in seawater was measured at low pH condition in all the experimental tanks. Though the data clearly show the difference in concentration and uptake of polonium at different pH conditions, it is not known if lower pH is affecting the adsorbed or absorbed fraction. A detailed investigation will be required to understand the process as it can have a significant effect on biomagnification and marine food chain transfer under changing climatic scenarios.
气候变化的影响，如海洋酸化（OA），已知会影响痕量金属的分布。本实验研究首次提供了在不同 pH 值条件下五种微藻物种中 Po 吸收速率和 Po 浓度的数据。该实验在三个 pH 值条件 8.2、8.0 和 7.5 下进行了重复，代表了根据 IPCC RCP8.5 预测的当前和未来气候变化情景。在 Thalassiosira weissflogi 中，浮游植物对 Po 的吸收最高，即在 8.2 pH 时，83%的 Po 示踪剂被吸收，而在 7.5 pH 时，吸收最低，相当于 20%。在这些微藻中，Po 浓度也表现出类似的行为，Po 浓度范围在 3.16±0.03 至 11.6±0.04 Bq kg 湿重（ww）之间，在 8.2 pH 的 Thalassioria weissflogi 中最高，在 7.5 pH 的 Dunaliella salina 中最低。Po 的吸收和浓度差异在物种之间以及 pH 处理之间均具有统计学意义（p<0.001），顺序为：Thalassiosira weissflogi>Tetraselmis suecica>Chaetoceros muelleri>Isochrysis galbana>Dunaliella salina 和 8.2>8.0>7.5。在所有实验水槽中，在低 pH 条件下测量到海水中 Po 的浓度更高。尽管数据清楚地显示了不同 pH 值条件下 Po 浓度和吸收的差异，但尚不清楚较低的 pH 是否会影响吸附或吸收部分。需要进行详细调查以了解这一过程，因为它可能会对变化的气候情景下的生物放大和海洋食物链转移产生重大影响。
