Abstract：
We obtained historical and observational data on phytoplankton communities from 1959 to 2023 to explore the responses of the phytoplankton community structure to long-term environmental changes in the southern Yellow Sea (SYS), China. The results revealed a decrease in the proportions of diatom cell abundance within the phytoplankton community by 8 %, accompanied by a corresponding increase in that of dinoflagellates. Dominant phytoplankton species were mainly chain-forming diatoms before 2000, and large dinoflagellate species from the genera Tripos and Noctiluca increased their dominance after 2000. Warm-water phytoplankton species have increased in dominance over the study period. Correlation analysis revealed that the ocean warming and alterations in nutrient structure (N/P and Si/N ratios) were mostly responsible for the long-term evolution trend, and these changes may result in an increase in dinoflagellate harmful algal blooms, reduced efficiency of the biological carbon pump, and heightened hypoxia in the future, which should draw our attention.
摘要：
我们获得了1959年至2023年浮游植物群落的历史和观测数据，以探索南黄海浮游植物群落结构对长期环境变化的响应（SYS），中国。结果表明，浮游植物群落中硅藻细胞丰度的比例下降了8％，伴随着鞭毛藻的相应增加。在2000年之前，优势浮游植物种类主要是成链硅藻，而在2000年之后，来自Tripos和Noctiluca属的大型鞭毛藻种类增加了它们的优势。在研究期间，温水浮游植物物种的优势有所增加。相关分析表明，海洋变暖和养分结构（N/P和Si/N比）的变化是长期演变趋势的主要原因。这些变化可能会导致鞭毛藻有害藻华的增加，降低了生物碳泵的效率，在未来会加剧缺氧，这应该引起我们的注意。
