Effects of uptake of carbon and nutrients (nitrogen, phosphorous and silicon) on pH among phytoplankton species: implications for ocean acidification feedback mechanisms. Anthropogenic CO2 emission has caused a decrease in the ocean pH, which may affect coral reefs. The project will study two processes, as the feedback mechanisms, which can increase pH in seawater, uptake of additional CO2 by algae directly and stimulated by the human input of nitrogen and phosphorus.