I highly recommend you read this article "Ocean Alkalinity Enhancement Through Restoration of Blue Carbon Ecosystems". I think you can get your answer.

Dr Fatemeh Kachoueiyan thank you for your contribution to the discussion

Carbon is captured by phytoplankton in photosynthesis. Carbon is transferred to zooplankton when they eat phytoplankton. Carbon travels to the bottom of the ocean: In the faces of zooplankton which sink. For eons, the world's oceans have been sucking carbon dioxide out of the atmosphere and releasing it again in a steady inhale and exhale. The ocean takes up carbon dioxide through photosynthesis by plant-like organisms (phytoplankton), as well as by simple chemistry: carbon dioxide dissolves in water. Phytoplankton are microscopic, one-celled organisms that drift in the sunlit surface areas of the world's oceans and are key to bringing carbon down into the ocean biological pump from the atmosphere via the process of photosynthesis. Carbon dioxide is more soluble in cold water, so at high latitudes where surface cooling occurs, carbon dioxide laden water sinks to the deep ocean and becomes part of the deep ocean circulation "conveyor belt", where it stays for hundreds of years. Phytoplankton is responsible for most of the transfer of carbon dioxide from the atmosphere to the ocean. Carbon dioxide is consumed during photosynthesis, and the carbon is incorporated in the phytoplankton, just as carbon is stored in the wood and leaves of a tree. The biological pump (or ocean carbon biological pump or marine biological carbon pump) is the ocean's biologically driven sequestration of carbon from the atmosphere and land runoff to the ocean interior and seafloor sediments. There are two main types of inorganic carbon that are found in the oceans. Dissolved inorganic carbon (DIC) is made up of bicarbonate (HCO3−), carbonate (CO32−) and carbon dioxide (including both dissolved CO2 and carbonic acid H2CO3). Fish and other animals in the ocean breathe oxygen and give off carbon dioxide (CO2), just like land animals. Ocean plants take in the carbon dioxide and give off oxygen, just like land plants. The ocean is great at sucking up CO2 from the air. Through the process of photosynthesis, carbon dioxide is pulled from the air to produce food made from carbon for plant growth. Carbon moves from plants to animals. Through food chains, the carbon that is in plants moves to the animals that eats them. Animals that eat other animals get the carbon from their food too. While the solubility pump serves to concentrate dissolved inorganic carbon (CO2 plus bicarbonate and carbonate ions) in the deep oceans, the biological carbon pump (a key natural process and a major component of the global carbon cycle that regulates atmospheric CO2 levels) transfers both organic and inorganic carbon. The ocean "solubility pump" removes atmospheric carbon dioxide as air mixes with and dissolves into the upper ocean. The biological pump is the set of processes by which inorganic carbon is fixed into organic matter via photosynthesis and then sequestered away from the atmosphere generally by transport into the deep ocean. Carbon is dissolved in ocean water. The exchange of carbon dioxide between the atmosphere and ocean is a critical aspect of climate change. As carbon dioxide increases in the atmosphere, the ocean absorbs the extra carbon dioxide to maintain chemical equilibrium. The bacterial 'feed' on the dead remains, and change the organic carbon back into carbon dioxide, water and mineral nutrients. The transformation of carbon dioxide and nutrients into organic carbon, its sinking into the in the deep ocean, and its decomposition at depth, is known as the biological carbon pump.

Carbon is transported down to deep ocean sediments through two primary mechanisms: the biological pump and the solubility pump. Both of these processes are crucial for regulating the carbon cycle in the oceans and sequestering carbon in the deep sea. However i recommend the following research articles:

"Article Sensitivities of marine carbon fluxes to ocean change

"Article Ocean Carbon Pumps: Analysis of Relative Strengths and Effic...

Dr Imran Ud Din thank you for your contribution to the discussion

Phytoplankton are microscopic, one-celled organisms that drift in the sunlit surface areas of the world's oceans and are key to bringing carbon down into the ocean biological pump from the atmosphere via the process of photosynthesis. Phytoplanktons are the main reason the ocean is one of the biggest carbon sinks. These microscopic marine algae and bacteria play a huge role in the world's carbon cycle - absorbing about as much carbon as all the plants and trees on land combined.Carbon is captured by phytoplankton in photosynthesis. Carbon is transferred to zooplankton when they eat phytoplankton. Carbon travels to the bottom of the ocean: In the faces of zooplankton which sink. After the organisms die, they sink to the seafloor. Over time, layers of shells and sediment are cemented together and turn to rock, storing the carbon in stone limestone and its derivatives.There are two main types of inorganic carbon that are found in the oceans. Dissolved inorganic carbon (DIC) is made up of bicarbonate (HCO3−), carbonate (CO32−) and carbon dioxide (including both dissolved CO2 and carbonic acid H2CO3). Atmospheric carbon dioxide dissolves in rainwater, making it slightly acidic. This dissolves rocks, allowing the carbon to flow down rivers and into the ocean, deposited in new rocks usually calcium carbonate. But carbon in sedimentary rocks, with an average residence time of 400 million years, participates little in global carbon circulation over shorter times. The average residence times of carbon in the atmosphere (5 years), the biosphere (13 years), and the oceans (350 years) are much shorter. The ocean absorbs much of the carbon dioxide that is released from burning fossil fuels. This extra carbon dioxide is lowering the ocean's pH, through a process called ocean acidification. Carbon dioxide is naturally stored in the ocean through chemical processes, either as a dissolved gas or, over a longer time scale, as carbonate sediments on the seafloor. In fact, more than 70 percent of current CO2 emissions will eventually wind-up in the ocean. While the solubility pump serves to concentrate dissolved inorganic carbon (CO2 plus bicarbonate and carbonate ions) in the deep oceans, the biological carbon pump (a key natural process and a major component of the global carbon cycle that regulates atmospheric CO2 levels) transfers both organic and inorganic carbon. In oceanic biogeochemistry, the solubility pump is a physico-chemical process that transports carbon as dissolved inorganic carbon (DIC) from the ocean's surface to its interior. The biological pump is the set of processes by which inorganic carbon (e.g., carbon dioxide) is fixed into organic matter via photosynthesis and then sequestered away from the atmosphere generally by transport into the deep ocean.