Quantifying the Ocean's Biological Pump and Its Carbon Cycle Impacts on Global Scales
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Updated: Aug 29, 2025

Unraveling the Unseen Players in the Ocean - A Field Guide to Water Chemistry and Marine Microbiology
Published on: November 5, 2014
David A Siegel1, Timothy DeVries1, Ivona Cetinić2,3
1Earth Research Institute and Department of Geography, University of California, Santa Barbara, California, USA;
Abstract:
The biological pump transports organic matter, created by phytoplankton productivity in the well-lit surface ocean, to the ocean's dark interior, where it is consumed by animals and heterotrophic microbes and remineralized back to inorganic forms. This downward transport of organic matter sequesters carbon dioxide from exchange with the atmosphere on timescales of months to millennia, depending on where in the water column the respiration occurs. There are three primary export pathways that link the upper ocean to the interior: the gravitational, migrant, and mixing pumps. These pathways are regulated by vastly different mechanisms, making it challenging to quantify the impacts of the biological pump on the global carbon cycle. In this review, we assess progress toward creating a global accounting of carbon export and sequestration via the biological pump and suggest a path toward achieving this goal.
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