Effects of CO2-induced seawater acidification on microbial processes involving dissolved organic matter

Abstract We used laboratory experiments covering a wide range of carbon dioxide (CO 2 ) induced seawater acidification to simulate ocean CO 2 storage and assess the potential effects on heterotrophic microbial processes associated with labile dissolved organic matter (DOM). There was no noticeable effect of increased CO 2 concentration on short-term decomposition of labile DOM or nutrient uptake. However, microbial activities producing “new” DOM were apparently enhanced under treatments with 2000 or 5000 ppm CO 2 . Under these conditions, production of aggregates was inhibited in early stage. Both of acute and chronic effects should be included for assessment of biogeochemical cycle related to microbe process.