The carbon atoms in ocean water is one of the ways through which carbon is sequestered in nature.
Sequestration of carbon implies the storage of carbon either naturally or artificially for a very long time.
Carbon sequestration cuts off carbon from the normal biogeochemical cycle and stores it in natural reservoirs for a very long duration.
In nature, carbon is sequestered a whole lot through biological and chemical activities.
Phytoplanktons are food producers. When consumed by higher organisms, their organic materials which contains carbon can become sequestered when the consumer dies and falls to the bottom of the ocean.
Organisms that used carbonate to manufacture their shells in the ocean also sequesters carbon.
