Yanping Zhong, Peixuan Wang, Jinxin Chen, Xin Liu, Edward A. Laws, Bangqin Huang. Dynamic of phytoplankton community during varying intensities of the northeast monsoon in the Taiwan Strait[J]. Acta Oceanologica Sinica. doi: 10.1007/s13131-024-2381-0
Citation:
Yanping Zhong, Peixuan Wang, Jinxin Chen, Xin Liu, Edward A. Laws, Bangqin Huang. Dynamic of phytoplankton community during varying intensities of the northeast monsoon in the Taiwan Strait[J]. Acta Oceanologica Sinica. doi: 10.1007/s13131-024-2381-0
Yanping Zhong, Peixuan Wang, Jinxin Chen, Xin Liu, Edward A. Laws, Bangqin Huang. Dynamic of phytoplankton community during varying intensities of the northeast monsoon in the Taiwan Strait[J]. Acta Oceanologica Sinica. doi: 10.1007/s13131-024-2381-0
Citation:
Yanping Zhong, Peixuan Wang, Jinxin Chen, Xin Liu, Edward A. Laws, Bangqin Huang. Dynamic of phytoplankton community during varying intensities of the northeast monsoon in the Taiwan Strait[J]. Acta Oceanologica Sinica. doi: 10.1007/s13131-024-2381-0
National Observation and Research Station for the Taiwan Strait Marine Ecosystem, Fujian Provincial Key Laboratory of Coastal Ecology and Environmental Studies, College of the Environment and Ecology, Xiamen University, Xiamen 361102, China
2.
Fujian Province Key Laboratory for the Development of Bioactive Material from Marine Algae; College of Resources and Environmental Sciences, Quanzhou Normal University, Quanzhou 362000, China
3.
Southern Marine Science and Engineering Guangdong Laboratory (Zhuhai), Zhuhai 511458, China
4.
Department of Environmental Sciences, College of the Coast & Environment, Louisiana State University, Baton Rouge 70803, LA, USA
Funds:
This work is supported by the National Natural Science Foundation of China under contract Nos 42122044, 42206100, and 42141002; Southern Marine Science and Engineering Guangdong Laboratory (Zhuhai) under contract No. SML2021SP308.
The characteristics of the terrain of a strait can lead to a “fine tube” effect that enhances a monsoon and thereby affects the physical, chemical, and biological processes of marine ecosystems. This effect is a highly dynamic and complex phenomenon involving interactions among atmospheric, oceanic, and terrestrial systems, as well as biogeochemical cycles and biological responses driven by it. However, current understanding has been focused mainly on the differences between monsoons, and there have been few studies concerned with the weakening or strengthening of monsoons. To explore the biogeochemical and phytoplankton responses during varying intensities of the northeast (NE) monsoon in the Taiwan Strait (TWS), high-resolution, across-front observations combined with FerryBox online data and satellite observations were conducted in this study during a strong, moderate, and weak NE monsoon. The spatiotemporal changes of nutrient concentrations and phytoplankton communities were regulated by the dynamics of ocean currents forced by NE winds. The weakening of the NE monsoon caused shrinkage of the coastal currents that led to a reduction of nutrient concentrations and an alteration of the distribution patterns of phytoplankton communities along cross-front sections. Specifically, there was a notable decrease in the proportions of dinoflagellates and cryptophytes in inshore regions and of prasinophytes in offshore areas. This study showed for the first time the dynamics of phytoplankton with changes of ocean currents during varying intensities of the NE monsoon in a strait system. The findings helped to elucidate the general spatial patterns of the phytoplankton community based on satellite-derived surface temperature and wind patterns and further enhanced the understanding of biogeochemical cycles in marine systems.
Figure 1. The mean sea surface temperature (℃, a-e), wind velocity at 10 m above the sea surface (vectors, in m/s, a-e), the horizontal gradient of temperature (℃/100 km, f-j) and chlorophyll a (k-o) in the Taiwan Strait in January (a, f, k), February (b, g, l), March (c, h, m), April (d, i, n), May (e, j, o) between 2010 and 2022. The blue and black lines represent the 17℃ and 20℃ isotherms.
Figure 2. Averaged SST (shading, in ℃) during the observations in March 2019 (a), April 2018 (b), and May 2017 (c) and averaged wind velocity at 10 m above the sea surface (vectors, in m/s, a-c) in the Taiwan Strait before two weeks of the observations in March 2019 (a), April 2018 (b), and May 2017 (c); The horizontal gradient of temperature (℃/100 km) in the Taiwan Strait during observations with strong (d), moderate (e), and weak (f) NE wind; Changes of temperature, salinity, and fluorescent chlorophyll along Transects G, F, and A during the cruises of 2019 (g), 2018 (h) and 2017(i). The grey rectangles represent the frontal zones.
Figure 3. Potential temperature–salinity diagrams during the observations with the strong (a), moderate (b), and weak (c) NE wind.
Figure 4. Vertical profiles of sea temperature (℃, a, b, c), salinity (d, e, f), potential density anomaly (kg/m3, g, h, i), buoyancy frequency (cycl/h, j, k, l), and fluorescence (μg/L, m, n, o) along Transects G (a, d, g, j, m), F (b, e, h, k, n), and A (c, f, i, l, o) under the forcing of strong, moderate, and weak NE wind. Stations in white frames represent the frontal zones.
Figure 5. Vertical profiles of nitrate + nitrite (NOX, μmol/L, a, b, c), phosphate (PO4, μmol/L, d, e, f), and silicate (SiO3, μmol/L, g, h, i) along the Transects G, F, and A under the forcing of strong, moderate, and weak NE wind.
Figure 6. Vertical profiles of total ChlorophyII a (TChl a)(ng/L, a, b, c), dinoflagellate (Dino, ng/L, d, e, f), diatoms (Diat, ng/L, g, h, i), cryptophytes (cryp, ng/L, j, k, l), prasinophytes (Pras, ng/L, m, n, o), haptophytes type 8 (Hapt. T8, ng/L, p, q, r), Synechococcus (Syne, ng/L, s, t, u), and Prochlorococcus (Proc, ng/L, v, w, x) along the Transects G, F, and A under the forcing of strong, moderate, and weak NE wind.
Figure 7. Phytoplankton compositions in the surface water (upper) and average depth-integrated (bottom) along Transects G (left), F (middle), A (left) under the forcing of strong, moderate, and weak NE wind. CW: coastal water; FZ: the frontal zone; WW: the warm water
Figure 8. Principal coordinates analysis (PCoA) based on the Bray-Curitis dissimilarities of the phytoplankton community in different zones (left), and canonical correlation analysis (CCA) of phytoplankton community and environmental factors. CW: coastal water; FZ: the frontal zone; WW: the warm water
Figure 9. The ecological responses to the various ocean currents with the weakening of the NE wind in the TWS. (a) It represents the ecological responses to the strong NE wind, when the western TWS was influenced by the large influence of the coastal currents; (b) It represents the ecological responses to with the weakening of NE wind, when the western TWS was less influenced by the coastal currents.
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