The University of Southampton
University of Southampton Institutional Repository

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

Role of zooplankton in determining the efficiency of the biological carbon pump
Role of zooplankton in determining the efficiency of the biological carbon pump
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.
1726-4170
177-186
Cavan, Emma L.
aca6bc0e-f2ba-4378-8be6-4da7e1e9da31
Henson, Stephanie A.
d6532e17-a65b-4d7b-9ee3-755ecb565c19
Belcher, Anna
604905f0-adc0-4503-b8b3-d5b5f9960771
Sanders, Richard
02c163c1-8f5e-49ad-857c-d28f7da66c65
Cavan, Emma L.
aca6bc0e-f2ba-4378-8be6-4da7e1e9da31
Henson, Stephanie A.
d6532e17-a65b-4d7b-9ee3-755ecb565c19
Belcher, Anna
604905f0-adc0-4503-b8b3-d5b5f9960771
Sanders, Richard
02c163c1-8f5e-49ad-857c-d28f7da66c65

Cavan, Emma L., Henson, Stephanie A., Belcher, Anna and Sanders, Richard (2017) Role of zooplankton in determining the efficiency of the biological carbon pump. Biogeosciences, 14, 177-186. (doi:10.5194/bg-14-177-2017).

Record type: Article

Abstract

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.

Text
Cavan et al bg-2016-251.pdf - Accepted Manuscript
Restricted to Repository staff only
Request a copy
Text
bg-14-177-2017.pdf - Version of Record
Available under License Creative Commons Attribution.
Download (2MB)
Text
Supplement - Version of Record
Available under License Creative Commons Attribution.
Download (840kB)
Text
bg-2016-251.pdf - Other
Available under License Other.
Download (1MB)
Text
bg-2016-251-supplement.pdf - Other
Available under License Other.
Download (274kB)

Show all 5 downloads.

More information

Accepted/In Press date: 17 June 2016
e-pub ahead of print date: 12 January 2017
Organisations: Ocean and Earth Science, Marine Biogeochemistry

Identifiers

Local EPrints ID: 403842
URI: https://eprints.soton.ac.uk/id/eprint/403842
ISSN: 1726-4170
PURE UUID: 7ad793ac-2340-4e66-b666-4006de0f6c27

Catalogue record

Date deposited: 14 Dec 2016 10:39
Last modified: 09 Dec 2019 19:20

Export record

Altmetrics

Contributors

Author: Emma L. Cavan
Author: Anna Belcher
Author: Richard Sanders

University divisions

Download statistics

Downloads from ePrints over the past year. Other digital versions may also be available to download e.g. from the publisher's website.

View more statistics

Atom RSS 1.0 RSS 2.0

Contact ePrints Soton: eprints@soton.ac.uk

ePrints Soton supports OAI 2.0 with a base URL of https://eprints.soton.ac.uk/cgi/oai2

This repository has been built using EPrints software, developed at the University of Southampton, but available to everyone to use.

We use cookies to ensure that we give you the best experience on our website. If you continue without changing your settings, we will assume that you are happy to receive cookies on the University of Southampton website.

×