School of Science Department of Ocean Science 55 Department of Ocean Science Phytoplankton Biomass and Community Composition in Hong Kong Coastal Waters Supervisor: LIU Hongbin / OCES Student: LEUNG Chak On / BCB Course: UROP1100, Fall Water quality is one of the main issues in marine fish culturing. A lot of factors can be associated the change in the water quality, such as temperature, the concentration of nutrients and pollutants, and ocean current. Therefore, a constant monitoring in water quality is necessary. HKUST has been in collaboration AFCD to measure the water samples in all HK marine culture zones. In this report, temperature, dissolved oxygen and chlorophyll a concentration were measured in August and September 2021, and the causes of their relationship and changes over time were investigated. It turned out that temperature was irrelevant to the change in water quality, but several factors were critical to it. Study on the Adaptation and Physiological Responses of Synechococcus Isolates from Different Oceans Supervisor: LIU Hongbin / OCES Student: HUANG Jingxian / SSCI Course: UROP1000, Summer Synechococcus are one of the most widespread photoautotrophs cyanobacteria in the marine environment, diverse clades of Synechococcus stand significant roles in the ocean ecosystem and marine primary production. Studying of their physiological responses and adaptation to variable environmental conditions may give clues of the principle that how do Synechococcus distribute in the global oceans and subsequently influence the biogeochemical cycle. In this study, we isolated eleven strains of Synechococcus from different regions of ocean and transferred the original sample to do the daily sampling under certain specific temperatures to gain the growth rate of them. The thermal responses of diverse clades of Synechococcus under different temperatures is the focus in this study. Study on the Adaptation and Physiological Responses of Synechococcus Isolates from Different Oceans Supervisor: LIU Hongbin / OCES Student: LI Ching / BISC Course: UROP1000, Summer Temperature is one of the most important parameters impacting the growth of cynobacteria which is responsible for transferring energy down the food chain and act as the role of carbon sink. In our experiment, we obtained 10 strains of Synechococcus isolated from different ocean. Attempting to find out their growth rate at different temperature. Our data show that there is positive relationship between the growth rate of Synechococcus and temperature. We predict Synechococcus will have wider distribution and higher abundance in the future under the influence of global warming and illustrate possible impacts from the growing Synechococcus such as increased primary activity and possible harm to the shelves water food web.