Skip Navigation



JPR Advance Access published online on July 27, 2005
Journal of Plankton Research, doi:10.1093/plankt/fbi049
This Article
Right arrow Full Text (PDF)
Right arrow All Versions of this Article:
27/10/959    most recent
fbi049v1
Right arrow Alert me when this article is cited
Right arrow Alert me if a correction is posted
Services
Right arrow Email this article to a friend
Right arrow Similar articles in this journal
Right arrow Alert me to new issues of the journal
Right arrow Add to My Personal Archive
Right arrow Download to citation manager
Right arrowRequest Permissions
Google Scholar
Right arrow Articles by Schnetzer, A.
Right arrow Articles by Caron, D. A.
Right arrow Search for Related Content
PubMed
Right arrow Articles by Schnetzer, A.
Right arrow Articles by Caron, D. A.
Social Bookmarking
Add to CiteULike   Add to Connotea   Add to Del.icio.us  
What's this?

© The Author 2005. Published by Oxford University Press. All rights reserved. For Permissions, please email: journals.permissions@oupjournals.org
Received February 17, 2005
Accepted June 10, 2005

Article

Copepod Grazing Impact on the Trophic Structure of the Microbial Assemblage of the San Pedro Channel, California

Astrid Schnetzer 1* and David A. Caron 1

1 Department of Biological Sciences, University of Southern California, 3616 Trousdale Parkway, Los Angeles, 90089-0371, California, USA

* To whom correspondence should be addressed.
Astrid Schnetzer, E-mail: astrids{at}usc.edu


  Abstract

In August 2002 and March 2003 the trophic structure of the microbial assemblage from the San Pedro Channel, California was studied following the experimental alteration of the number of copepods. Changes in the abundance/biomass of microorganisms < 80 µm during 3-day incubations were monitored in 1) the absence of metazoa > 80 µm, 2) the presence of natural abundances of metazoa and 3) the presence of an elevated number of copepods. Prokaryotes and small-sized eukaryotes (< 4 µm) dominated plankton biomass during both experimental months. Diatoms numerically dominated the 10 - 80 µm plankton in August 2002, but ciliate and heterotrophic dinoflagellate biomass generally exceeded diatom biomass on both dates. Ingestion of protozooplankton (predominantly ciliates) contributed substantially to copepod daily carbon rations. The adult copepod assemblage removed 4.6% and 36% per day of the microzooplankton standing stocks (10 - 80 µm size fraction) in August and March, respectively. Elevated copepod grazing pressure on protozooplankton resulted in increased biomass of nanoplankton (< 5 µm) presumably via a trophic cascade. Accordingly, the copepod - protozoan trophic link appears to be a key factor structuring the planktonic microbial assemblage in the San Pedro Channel.

Keywords: Copepod grazing, Microbial Assemblages, Trophic Cascade, Protozoa.
Communicating Editor: KJ Flynn
Add to CiteULike CiteULike   Add to Connotea Connotea   Add to Del.icio.us Del.icio.us    What's this?


This article has been cited by other articles:


Home page
 J PLANKTON RESHome page
R. Sinistro
Top-down and bottom-up regulation of planktonic communities in a warm temperate wetland
J. Plankton Res., November 22, 2009; (2009) fbp114v1.
[Abstract] [Full Text] [PDF]


Disclaimer: Please note that abstracts for content published before 1996 were created through digital scanning and may therefore not exactly replicate the text of the original print issues. All efforts have been made to ensure accuracy, but the Publisher will not be held responsible for any remaining inaccuracies. If you require any further clarification, please contact our Customer Services Department.