The reason why water is so central to life is because of its marvelous solvent capabilities. Oceans have taken up the clean up job by dissolving a third of the carbon dioxide emitted in the atmosphere since the industrial age. The carbon in the atmosphere is in equilibrium with the carbon in the oceans. Emitting carbon in the air, thus, increases its concentration in the water.
singular and plural, no "s": Phytoplanktons.
FYI upwelling delivers nutrients and alkalinity and trace iron and cold water: kill 4 birds with one upwell!