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Role of zooplankton in determining the efficiency of the biological carbon pump


Cavan, EL and Henson, SA and Belcher, A and Sanders, R, Role of zooplankton in determining the efficiency of the biological carbon pump, Biogeosciences, 14 pp. 177-186. ISSN 1726-4170 (2017) [Refereed Article]


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Copyright 2017 Authors. Licensed under Creative Commons Attribution 3.0 Unported (CC BY 3.0)

DOI: doi:10.5194/bg-14-177-2017


The efficiency of the ocean's biological carbon pump (BCPeff – here the product of particle export and transfer efficiencies) plays a key role in the air–sea partitioning of CO2. Despite its importance in the global carbon cycle, the biological processes that control BCPeff are poorly known. We investigate the potential role that zooplankton play in the biological carbon pump using both in situ observations and model output. Observed and modelled estimates of fast, slow, and total sinking fluxes are presented from three oceanic sites: the Atlantic sector of the Southern Ocean, the temperate North Atlantic, and the equatorial Pacific oxygen minimum zone (OMZ). We find that observed particle export efficiency is inversely related to primary production likely due to zooplankton grazing, in direct contrast to the model estimates. The model and observations show strongest agreement in remineralization coefficients and BCPeff at the OMZ site where zooplankton processing of particles in the mesopelagic zone is thought to be low. As the model has limited representation of zooplankton-mediated remineralization processes, we suggest that these results point to the importance of zooplankton in setting BCPeff, including particle grazing and fragmentation, and the effect of diel vertical migration. We suggest that improving parameterizations of zooplankton processes may increase the fidelity of biogeochemical model estimates of the biological carbon pump. Future changes in climate such as the expansion of OMZs may decrease the role of zooplankton in the biological carbon pump globally, hence increasing its efficiency.

Item Details

Item Type:Refereed Article
Keywords:zooplankton, biological carbon pump, global
Research Division:Earth Sciences
Research Group:Oceanography
Research Field:Biological oceanography
Objective Division:Environmental Management
Objective Group:Fresh, ground and surface water systems and management
Objective Field:Measurement and assessment of freshwater quality (incl. physical and chemical conditions of water)
UTAS Author:Cavan, EL (Dr Emma Cavan)
ID Code:116303
Year Published:2017
Web of Science® Times Cited:50
Deposited By:Ecology and Biodiversity
Deposited On:2017-05-04
Last Modified:2019-09-19
Downloads:84 View Download Statistics

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