There is absorption of carbon dioxide
by the oceans through physicochemical (air-sea surface exchange) and biological
processes. During physicochemical process, molecules of CO2 get into the ocean
by diffusing into the sea surface waters and dissolving. Various factors such
as wind, sea surface mixing, concentrations of CO2, and the temperature of the
water influences the amount of CO2 that diffuses and dissolves in the ocean
surface water. Also, during biological processes, dead cells, shells and other
parts of dead organisms get decayed and releases carbon dioxide at the bottom
of the water.
The aggregate (collective) of plants and plantlike organisms in plankton.
100% of them would be blue! :)