733 / 2024-09-19 10:45:38
The summer pattern of phytoplankton pigment assemblages in response to water masses in the Yellow Sea
Phytoplankton; Stratification; Yellow Sea Cold Water Mass; Nutrients
Session 19 - Marine Plankton Ecosystem and Global Climate Change
Abstract Accepted
The property of water mass plays an important role in determining the distribution of phytoplankton in the ocean. Summer stratification in the Yellow Sea constrains water exchange and differentiates the properties of the Yellow Sea Cold Water Mass (YSCWM) and surface water, which in turn affects the spatiotemporal patterns of phytoplankton communities. Here, based on four summer cruises in the Yellow Sea, we examined the response of phytoplankton pigment assemblages to three water masses, including surface water (water mass I, WM-I), pycnocline mass (WM-II), and the YSCWM (WM-III). Considering the opportunities for group dominance across the four cruises, Cyanobacteria, Haptophyceae, Chlorophyceae and Cryptophyceae preferred living in WM-I, characterized by relatively high temperature and light intensity but low nutrients; Bacillariophyceae, Chlorophyceae, Cyanobacteria and Dinophyceae dominated in WM-III, with relatively low temperature and light intensity but high nutrients. In comparison, the highest diversity of the dominant pigment groups was observed in WM-II with intermediate temperature, light and nutrient levels. The Dirichlet regression model identified the key environmental factors driving changes in phytoplankton assemblages in WM-I, II and III as dissolved inorganic phosphate (DIP), DIP and light, and ammonium and dissolved silica, respectively. Under the impacts of global warming and other stressors, the fluctuations of key driving forces and their potential ecological implications necessitate further investigation.