Key Laboratory of Marine Ecology and Environmental Sciences, Institute of Oceanology, Chinese Academy of Sciences, Qingdao, 266404, China; University of Chinese Academy of Sciences, Beijing, 100049, China; Function Laboratory of Marine Ecology and Environmental Sciences, Qingdao Marine Science and Technology Center, Qingdao, 266237, China.
Shandong Freshwater Fisheries Research Institute, Shandong Consulting Association of Ocean Engineering, Jinan, 250013, China.
Environ Res. 2024 Oct 15;259:119536. doi: 10.1016/j.envres.2024.119536. Epub 2024 Jul 2.
The acidification of the marginal seawater was a more intricate process than the ocean. Although some studies have been done on seasonal acidification in the bottom water of Chinese marginal seas, research on surface water acidification has still been insufficient. We analyzed the acidification properties and controlling factors in the Bohai Sea (BS) and Yellow Sea (YS) surface water during April 2023. The observation showed that the average surface water pH of the BS, North Yellow Sea (NYS), and South Yellow Sea (SYS) were 8.09 ± 0.06, 8.13 ± 0.05, and 8.15 ± 0.05. Phytoplankton significantly impacted pH and Ω, while riverine inputs and biological activity played a vital role in controlling DIC and TA. The Yellow River significantly impacted the BS. The North Yellow Sea Cold Water Mass had a limited impact on acidification, while the South Yellow Sea Cold Water Mass significantly affected the SYS. Regarding seasonal fluctuations, Ω was significantly higher in summer than in other seasons. DIC and TA showed different patterns in both the BS and YS, with a minimal fluctuation in pH. Over the last two decades, the pH in the BS showed a slight annual decline, and the rate of change was (-1.45 ± 2.19) × 10 yr. In contrast, the NYS and SYS have slightly risen, with rates of change of (2.39 ± 1.24) × 10 and (1.23 ± 0.76) × 10 yr. We believed that surface water acidification in the BS and YS did not follow the expected trend of significant acidification observed in open oceanic regions. Instead, the acidification process in these marginal seas was dominated by local factors such as riverine inputs, biological activity, and cold water masses, resulting in minimal pH changes over the last two decades.
边缘海的酸化过程比海洋更为复杂。尽管已经有一些关于中国边缘海底层水季节性酸化的研究，但对表层水酸化的研究仍然不足。我们分析了 2023 年 4 月渤海（BS）和黄海（YS）表层水的酸化特性和控制因素。观测结果表明，BS、北黄海（NYS）和南黄海（SYS）的表层水平均 pH 值分别为 8.09±0.06、8.13±0.05 和 8.15±0.05。浮游植物对 pH 和 Ω有显著影响，而河流输入和生物活性对 DIC 和 TA 起着至关重要的控制作用。黄河对 BS 有显著影响。北黄海冷水团对酸化的影响有限，而南黄海冷水团则显著影响 SYS。就季节性波动而言，夏季 Ω显著高于其他季节。BS 和 YS 中的 DIC 和 TA 呈现出不同的模式，pH 值波动较小。在过去的二十年中，BS 的 pH 值呈现出轻微的年下降趋势，变化率为(-1.45±2.19)×10 yr。相比之下，NYS 和 SYS 略有上升，变化率分别为(2.39±1.24)×10和(1.23±0.76)×10 yr。我们认为，BS 和 YS 的表层水酸化并没有遵循开阔海洋地区酸化显著的预期趋势。相反，这些边缘海的酸化过程主要受河流输入、生物活性和冷水团等局部因素的影响，在过去的二十年中 pH 值变化较小。
