Zooplankton vertical migration and the active transport of dissolved organic and inorganic carbon in the Sargasso Sea

The least known component of the “biological pump” is the active transport of carbon and nutrients by diel vertical migration of zooplankton. We measured CO 2 respiration and dissolved organic carbon (DOC) excretion by individual species of common vertically migrating zooplankton at the US JGOFS Ber...

Full description

Saved in:
Bibliographic Details
Published in:Deep-sea research. Part I, Oceanographic research papers Oceanographic research papers, 2000, Vol.47 (1), p.137-158
Main Authors: Steinberg, Deborah K., Carlson, Craig A., Bates, Nicholas R., Goldthwait, Sarah A., Madin, Laurence P., Michaels, Anthony F.
Format: Article
Language:English
Subjects:
Animal and plant ecology
Animal, plant and microbial ecology
Bermuda Atlantic Time-series Study (BATS)
Biological and medical sciences
Carbon
Carbon dioxide
Dissolved organic carbon (DOC)
Fundamental and applied biological sciences. Psychology
Marine
Oceanography
Plankton
Sargasso Sea
Sea water ecosystems
Synecology
Vertical migration
Zooplankton
Citations: Items that this one cites
Items that cite this one
Online Access:Get full text
Tags: Add Tag
No Tags, Be the first to tag this record!
Description
Summary:The least known component of the “biological pump” is the active transport of carbon and nutrients by diel vertical migration of zooplankton. We measured CO 2 respiration and dissolved organic carbon (DOC) excretion by individual species of common vertically migrating zooplankton at the US JGOFS Bermuda Atlantic Time-series Study (BATS) station. The inclusion of DOC excretion in this study builds on published research on active transport by respiration of inorganic carbon and allows a direct assessment of the role of zooplankton in the production of dissolved organic matter used in midwater microbial processes. On average, excretion of DOC makes up 24% (range=5–42%) of the total C metabolized (excreted+respired) and could represent a significant augmentation to the vertical flux that has already been documented for respiratory CO 2 flux by migrant zooplankton. Migratory fluxes were compared to other transport processes at BATS. Estimates of combined active transport of CO 2 and DOC by migrators at BATS averaged 7.8% and reached 38.6% of mean sinking POC flux at 150 m, and reached 71.4% of mean sinking POC flux at 300 m. DOC export by migrator excretion averaged 1.9% and reached 13.3% of annual DOC export by physical mixing at this site. During most of the year when deep mixing does not occur, diel migration by zooplankton could provide a supply of DOC to the deeper layers that is available for use by the microbial community. A carbon budget comparing migrant zooplankton transport to the balance of fluxes in the 300–600 m depth strata at BATS shows on average that the total migrant flux supplies 37% of the organic carbon remineralized in this layer, and that migrant DOC flux is more than 3 times the DOC flux gradient by diapycnal mixing. New estimates of active transport of both organic and inorganic carbon by migrants may help resolve observed imbalances in the C budget at BATS, but the magnitude is highly dependent on the biomass of the migrating community.
ISSN:0967-0637
1879-0119
DOI:10.1016/S0967-0637(99)00052-7