Calcareous nanoplankton

Calcareous nanoplankton are tiny marine organisms that create calcium carbonate shells or tests, typically measuring just a few micrometers in size. They play a crucial role in ocean ecosystems and the global carbon cycle, as they help sequester carbon when they die and their shells sink to the ocean floor. This process can influence climate by regulating atmospheric CO2 levels. These organisms are often studied in paleoclimatology, as their fossils provide insight into past ocean conditions and climate changes. Examples include coccolithophores, which are important for both marine food webs and as indicators of environmental change.