Bacterial production and losses to predators along an open ocean productivity gradient in the Subtropical North East Atlantic Ocean

Dolors Vaqué*, Laura Alonso-Sáez, Javier Arístegui, Susana Agusti, Carlos Duarte, M. Montserrat Sala, Evaristo Vázquez-Domínguez, Josep M. Gasol

*Corresponding author for this work

Research output: Contribution to journalArticlepeer-review

11 Scopus citations

Abstract

We estimated the bacterial production and losses to predators along an open ocean trophic gradient from coastal upwelling waters to oligotrophic waters in the Subtropical Northern Atlantic Ocean. Two zonal sections (21 and 26°N) extending from the NW African shelf to the Open Atlantic Ocean at 26°W were sampled during September-October 2002 (autumn), and May-June 2003 (spring). The main goal was to elucidate whether the impacts of bacterial losses were more important in upwelling rather than in offshore waters. Whereas temperature and salinity decreased and nutrient concentrations increased from offshore to the coastal upwelling regions, phytoplankton, ciliate and bacterial biomass followed a similar trend increasing towards the upwelling zone. In addition, heterotrophic nanoflagellate biomass, bacterial production and grazing rates on bacteria did not follow this pattern, although the highest activities were recorded at upwelling stations. However, at the stations not affected by upwelling the average impact on bacteria expressed as a percentage of bacterial production consumed by predators in autumn and spring (values that varied between 70% ± 6% and 129% ± 15%, respectively) was significantly higher than at the upwelling stations (where it ranged between 49% ± 7% and 68% ± 5%, respectively). Our results suggest that in the upwelling areas bacteria escape from predators and growth cannot be balanced by grazing, while it is at the oligotrophic open ocean stations when, on occasions, grazing can overcome bacterial production.

Original languageEnglish (US)
Pages (from-to)198-213
Number of pages16
JournalJournal of Plankton Research
Volume36
Issue number1
DOIs
StatePublished - Jan 27 2014

Keywords

  • NE Subtropical Atlantic
  • bacterial production
  • losses
  • protists
  • trophic gradient

ASJC Scopus subject areas

  • Ecology, Evolution, Behavior and Systematics
  • Aquatic Science
  • Ecology

Fingerprint Dive into the research topics of 'Bacterial production and losses to predators along an open ocean productivity gradient in the Subtropical North East Atlantic Ocean'. Together they form a unique fingerprint.

Cite this