Observation of a Takayama acrotrocha bloom in the Bohai Northern Yellow Sea in summer 2024 and its environmental drivers, insights from a three- year field study

Bohai-Northern Yellow Sea (BNYS) is a temperate semi-enclosed marginal sea system of high ecological and economic importance. Suffering from the climate change and the nutrient loads from both anthropogenic activity and river discharge, harmful algal blooms (HABs) were frequently outbreak in this area, with expanding spatial coverage, and changing species composition. Accordingly, we have conducted a three-year observation about the phytoplankton community dynamics from October 2022 to October 2024.