A study on Coccolithophores (microscopic marine algae) has been conducted by the National Centre for Polar and Ocean Research (NCPOR).
- Coccolithophores are single-celled algae living in the upper layers of the oceans. They play a key role in marine ecosystems and the carbon cycle for millions of years.
Importance of Coccolithophores:
- Build exoskeletons: Coccolithophores build exoskeletons from individual CaCO3 plates consisting of chalk and seashells building the tiny plates on their exterior.
- Remove carbon dioxide: Though carbon dioxide is produced during the formation of tiny plates, coccolithophores help in removing carbon dioxide from the atmosphere and ocean by consuming it during photosynthesis.
- At equilibrium, coccolithophores absorb more carbon dioxide than they produce, which is beneficial for the ocean ecosystem.
- Marine phytoplankton: Coccolithophores calcify marine phytoplankton that produces up to 40% of open ocean calcium carbonate and responsible for 20% of the global net marine primary productivity.
- There is a decrease in the concentration of oceanic calcium carbonate (CaCO3) in the Southern Indian ocean because of the increase in the concentration of another single-celled alga known as diatoms. This will affect the growth and skeleton structure of coccolithophores.
- According to The National Institute of Oceanography (NIO), abundance and diversity enrichment of coccolithophores in the southern Indian Ocean is dependent on time and influenced by several environmental factors such as silicate concentrations, calcium carbonate concentration, diatom abundance, light intensity and availability of macro and possibly micronutrient concentrations.
- The research revealed that the reduction of coccolithophore diversity in the early summer and late summer periods is due to an increase in the presence of diatom algae,
- Diatom algae occur after sea ice breakdown with climate change and ocean acidification and increase the silicate concentration in the waters of the Southern Ocean.
- The scientists also analyzed the maximum coccolithophore diversity during mid-summer in the Subtropical Zone (STZ) and Sub-Antarctic Zone (SAZ), which is controlled by elevated silicate, low temperature, and low salinity conditions.
- As per the results, the biogeographic boundaries of coccolithophores in the southern Indian Ocean are highly variable. It is controlled by environmental factors in early and mid-austral summer and grazing pressure in late austral summer.
- Physical forcing also may play a crucial role in the transport of coccoliths and coccospheres at high latitudes. It indicates that the southward extension of coccolithophores is important and may occur for short periods during the hot summer.
As per the results, climate change as a major reason for the altered coccolithophore calcification rate. Different environmental factors and the ability of the species to adapt to environmental changes due to climate change would determine the future coccolithophore calcite production.
These researches are very important for future intervention to bring positive changes in the marine ecosystem and the global carbon cycle.