Phytoplanktonic DOC and POC production in the Bransfield and Gerlache Straits as derived from kinetic experiments of 14C incorporation

Xosé Anxelu G. Morán*, Marta Estrada

*Corresponding author for this work

Research output: Contribution to journalArticlepeer-review

54 Scopus citations


The production rates of DOC and POC by phytoplankton during the FRUELA 95 cruise were estimated by means of time-course experiments of 14C-bicarbonate incorporation. A three-compartment carbon exchange model was used to avoid the artifacts that may appear in end-point experiments due to heterotrophic removal of recently released DOC. The study area was classified into three regions with different ecological characteristics: Bransfield Strait, Gerlache Strait and the Gerlache-Bransfield Confluence (GB Confluence). Percent extracellular release (PER) for all stations ranged from 3% to 47%, with an average of 24%. In surface (5 m depth) waters, POC and DOC production rates were higher in Gerlache Strait than in the GB Confluence and Bransfield Strait. PER values followed an opposite trend, with an average of 26% in Bransfield Strait, 17% in the GB Confluence and 13% in Gerlache Strait. In Gerlache Strait, PER at 10 m depth was significantly higher than at the surface. With pooled data from all experiments, there was a positive relationship between DOC and POC production rates (log-log), but the slope significantly smaller than 1.0 indicated an inverse trend between PER and primary production rate. Phytoplanktonically produced DOC appeared to meet carbon requirements of heterotrophic prokaryotes in the whole area. A positive relationship between prokaryotic heterotrophic production and DOC production rate was found only in Bransfield Strait. These differences are discussed in relationship with the ecological characteristics of the different regions.

Original languageEnglish (US)
Pages (from-to)769-786
Number of pages18
JournalDeep-Sea Research Part II: Topical Studies in Oceanography
Issue number4-5
StatePublished - 2002
Externally publishedYes

Bibliographical note

Funding Information:
We thank J.M. Gasol, C. Pedrós-Alió and D. Vaqué and two referees for critical review of the manuscript. We are also grateful to D. Vaqué and N. Guixa-Boixereu for the measurements of prokaryotic production and the crew of the R/V Hespérides for their help during the cruise. X.A.G.M. aknowledges the receipt of a FPI fellowship from the Spanish Ministry of Education. This work was supported by CICYT grant ANT94-1010.

ASJC Scopus subject areas

  • Oceanography


Dive into the research topics of 'Phytoplanktonic DOC and POC production in the Bransfield and Gerlache Straits as derived from kinetic experiments of 14C incorporation'. Together they form a unique fingerprint.

Cite this