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 274:17-29 (2004) - doi:10.3354/meps274017 Size-fractionated primary production, bacterial production and net community production in subtropical and tropical domains of the oligotrophic NE Atlantic in autumn Xosé Anxelu G. Morán1,*, Emilio Fernández2, Valesca Pérez2 1Instituto Español de Oceanografía, Centro Oceanográfico de Xixón, Camín de L¹Arbeyal, s/n, 33212 Xixón, Spain 2Facultad de Ciencias, Universidad de Vigo, Campus Lagoas-Marcosende, 36200 Vigo, Spain *Email: xelu.moran@gi.ieo.es ABSTRACT: The biomass and metabolism of the planktonic microbial community was assessed at 7 stations in the eastern subtropical and tropical domains of the North Atlantic subtropical gyre in autumn 2001. Picoplankton formed the bulk of phytoplankton (70 ± 3% SE of total chlorophyll a), with Prochlorococcus spp. as the dominant group and an increasing importance of picoeukaryotes and Synechococcus spp. in tropical waters. Autotrophic plankton biomass clearly exceeded that of heterotrophic bacteria in the upper 150 m, contradicting previous claims of marked inverted biomass pyramids in the oligotrophic ocean. Despite the dominance of picoplankton in biomass, primary production (range 153 to 337 mgC m-2 d-1) was mostly due to cells >2 µm (59 ± 3%). Primary production by microphytoplankton was significantly greater in the tropical domain. Bacterial heterotrophic production (range 6 to 22 mgC m-2 d-1) was always below 10% of primary production. This low value was probably related to the high proportion (56 ± 2%) of inactive bacteria (identified by their DNA content). Although bacterial activity covaried with primary productivity, bacterial carbon demand estimated by 2 models from the literature generally required organic matter input other than dissolved primary production. Given that community respiration (116 ± 32 mmolO2 m-2 d-1) also exceeded gross primary production (58 ± 32 mmolO2 m-2 d-1) at all but 1 station, our results confirm previous observations of the net heterotrophic balance in the oligotrophic NE Atlantic. KEY WORDS: Microbial plankton · Size-structure · Primary production · Bacterial production · Community metabolism · Subtropical gyre · Atlantic Ocean Full text in pdf format PreviousNextExport citation RSS - Facebook - Tweet - linkedIn Cited by Published in MEPS Vol. 274. Online publication date: June 24, 2004 Print ISSN: 0171-8630; Online ISSN: 1616-1599 Copyright © 2004 Inter-Research.
Talk to us
Join us for a 30 min session where you can share your feedback and ask us any queries you have
Disclaimer: All third-party content on this website/platform is and will remain the property of their respective owners and is provided on "as is" basis without any warranties, express or implied. Use of third-party content does not indicate any affiliation, sponsorship with or endorsement by them. Any references to third-party content is to identify the corresponding services and shall be considered fair use under The CopyrightLaw.