BIO-01 Harmful Algal Blooms
Spring bloom and associated temperature rise and nutrients pulse of the Xiamen Bay: A coupled physical-biological modeling approach
Yichong Wang* , College of the Environment and Ecology, Xiamen University
Qing Liu, College of the Ocean and Earth, Xiamen University
Bangqin Huang, College of the Environment and Ecology, Xiamen University
Peng Cheng, College of the Ocean and Earth, Xiamen University
Jixin Chen, College of the Ocean and Earth, Xiamen University

For this study, a high-resolution 3-dimension Regional Ocean Modeling System (ROMS) coupled with Nutrient-Phytoplankton-Zooplankton-Detritus (NPZD) model was developed in order to study the dynamics of the spring bloom in the Xiamen Bay (referred as XMB). Based on a simulation for May 2020, the results showed that the model was capable of reproducing the key characteristics of the XMB, such as the location and time of the outbreak, and nitrate and phosphate supply features during the outbreak, which revealed by the observations of cruises and buoy. However, the bloom intensity simulated by the model was not accurate enough. The simulation showed that XMB occurred during a period of temperature rise, accompanied by a nutrient pulse, and then demised as nutrients are depleted in just a few days. Model sensitivity analysis showed that the occurrence time and intensity of XMB were significantly influenced by phytoplankton growth rate and remineralization rate, respectively, while zooplankton feeding had little effect on XMB. In conclusion, the dynamics of XMB were mainly dominated by the Bottom-up effect caused by temperature and nutrients.