Rates of dissolved organic carbon production and bacterial activity in the eastern North Atlantic Subtropical Gyre during summer

Abstract

MEPS Marine Ecology Progress Series Contact the journal Facebook Twitter RSS Mailing List Subscribe to our mailing list via Mailchimp HomeLatest VolumeAbout the JournalEditorsTheme Sections MEPS 249:53-67 (2003) - doi:10.3354/meps249053 Rates of dissolved organic carbon production and bacterial activity in the eastern North Atlantic Subtropical Gyre during summer E. Teira1,5,*, M. J. Pazó1, M. Quevedo2, M. V. Fuentes3, F. X. Niell4, E. Fernández1 1Departamento de Ecología y Biología Animal, Universidad de Vigo, 36200 Vigo, Spain 2Departamento de Biología de Organismos y Sistemas, Universidad de Oviedo, 33071 Oviedo, Spain 3Departamento de Microbiología, and 4Departamento de Ecología, Universidad de Málaga, 29071 Málaga, Spain 5Present address: Royal Netherlands Institute for Sea Research (NIOZ), Department of Biological Oceanography, PO Box 59, 1790 AB Den Burg, The Netherlands *Email: teira@nioz.nl ABSTRACT: Rates of particulate organic carbon (POC) production, dissolved organic carbon (DOC) production and bacterial production were measured at 8 stations in the eastern North Atlantic Subtropical Gyre during August 1998. The euphotic-depth-integrated POC rate was on average 27 mgC m-2 h-1. The corresponding averaged integrated DOC production rate was 5 mgC m-2 h-1, i.e. about 20% of the total primary production. No statistically significant relationship was found between the rates of POC and DOC production, suggesting that other processes besides phytoplankton exudation, such as cell lysis or protist grazing, could be implied in the release of dissolved organic materials to the oceanic environment. Euphotic-depth-integrated bacterial biomass and production were on average 214 mgC m-2 and 1.4 mgC m-2 h-1, respectively. The lack of correlation between the rates of DOC release and bacterial activity and a bacterial carbon demand (BCD, calculated using an estimated bacterial growth efficiency ranging from 11 to 18%) in excess of DOC production suggested the existence of additional organic carbon sources (both allochthonous and/or autochthonous reservoirs), apart from in situ phytoplankton-derived DOC production, for the maintenance of bacterial activity in this region during summer 1998. This uncoupling between phytoplankton and bacterioplankton could partially explain the heterotrophic metabolic balance in this oligotrophic region during summer 1998. KEY WORDS: Phytoplankton · Bacteria · Primary production · DOC production · Bacterial activity · Coupling · North Atlantic Subtropical Gyre Full text in pdf format PreviousNextExport citation RSS - Facebook - Tweet - linkedIn Cited by Published in MEPS Vol. 249. Online publication date: March 10, 2003 Print ISSN: 0171-8630; Online ISSN: 1616-1599 Copyright © 2003 Inter-Research.