Page 81 - 《渔业研究》2026年第2期

224 渔 业 研 究 第 48 卷

plicated and confusing ecology of Microcystis blooms growth factors of Pseudanabaena sp. in drinking water
[J]. mBio, 2020, 11(3): e00529 − 20. source reservoirs, southern China[J]. Sustainability, 2018,
［33］ Gao J S, Zhu J, Wang M W, et al. Dominance and 10(11): 3936.

Study on the ecological stoichiometric characteristics of the carbon-phosphorus
ratio in Shanzai Reservoir, Fujian Province

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HUANG Shiyu 1,2,3 ，WENG Yuxin ，SU Yuping 1,2,3* ，ZHOU Yuanyuan ，ZHENG Luwei 1,2,3 ，TANG Jian 1,2,3
[1. College of Environmental and Resource Sciences, College of Carbon Neutral Modern Industry,
Fujian Normal University, Fuzhou 350117, China;
2. Fujian Key Laboratory of Pollution Control & Resource, Fuzhou 350117, China;
3. Fujian Research Center for Happy River and Lake Health (Fujian Normal University), Fuzhou 350007, China]

Abstract: [Objective] Eutrophication-induced cyanobacterial blooms have posed a severe threat to water qual-
ity and ecosystem stability. This study aims to investigate the spatiotemporal distribution characteristics of the
dissolved inorganic carbon-to-total phosphorus ratio (DIC/TP) and its effects on the phytoplankton community
structure in reservoirs, and to evaluate the sensitivity of DIC/TP as an early-warning indicator for eutrophica-
tion. [Methods] From April 2023 to February 2024, water samples and phytoplankton samples were collected
at 5 sampling sites (reservoir center, dam front, Rixi inlet, Huangdi Cave, and river channel) in Shanzai Reser-
voir. Hydrological and physicochemical indicators, and concentrations of DIC, dissolved organic carbon (DOC)
and TP were measured. Analysis of variance (ANOVA) and correlation analysis were performed to explore the
correlations among these indicators. [Results] A total of 6 phyla and 51 genera of phytoplankton were identi-
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fied during the study period. The total phytoplankton density ranged from 1.90×10 to 2.71×10 cells·L , exhib-
iting a seasonal variation pattern of spring>summer>autumn>winter. The DIC/TP ratio varied from 12.0 to
825.4, with an average value of 178.9, and showed significant spatiotemporal differences. Its seasonal variation
followed the order of winter>autumn>summer>spring, while the spatial variation was in the sequence of reser-
voir center>dam front>Rixi inlet>Huangdi Cave>river channel. Correlation analysis revealed that the DIC/TP
ratio was extremely significantly negatively correlated with total phytoplankton density (r=−0.440) and cy-
anobacterial density (r=−0.480), whereas extremely significantly positively correlated with diatom density (all
P<0.001). Additionally, the ratio was also significantly correlated with the trophic state index and environmental
factors such as water temperature (WT) and Secchi disk depth (SD) (P<0.05). [Conclusion] The DIC/TP ratio
is a key factor regulating the phytoplankton community structure. Low DIC/TP ratios in spring and summer are
associated with high cyanobacterial bloom risks, while high ratios in winter favor the dominance of chloro-
phytes and diatoms. An increase in the DIC/TP ratio can drive the phytoplankton community to shift from cy-
anobacteria-dominated to chlorophyta- and bacillariophyta-dominated. Compared with the nitrogen-to-phos-
phorus ratio (TN/TP), the DIC/TP ratio responds more sensitively to eutrophication status, making it a valuable
early-warning indicator for reservoir eutrophication. This study deepens the understanding of the effects of the
DIC/TP ratio on phytoplankton community structure in reservoirs, providing a new theoretical perspective and
practical reference for the restoration of eutrophic water bodies.
Key words: the dissolved inorganic carbon-to-total phosphorus ratio (DIC/TP); phytoplankton; eutrophication;
Shanzai Reservoir