IR Home
AME
Home
Editors
Forthcoming
Information
Subscribe
Journals
Home
MEPS
AME
CR
DAO
ESEP
ESR
Search
Subscribe
Book Series
EE Books
Top Books
ESEP Books
Order
EEIU Brochures
(pdf format)
Discussion Forums
Home
Research
IR Research
Institutions
International Ecology Institute
Eco-Ethics International Union
Foundation
Otto Kinne Foundation
 | |
AME 35:79-91 (2004)
|
Abstract
|
Phytoplankton community response to a manipulation of bioavailable iron in HNLC waters of the subtropical Pacific Ocean
Melanie L. Eldridge1, Charles G. Trick3, Melissa B. Alm4, Giacomo R. DiTullio4, Eden L. Rue5, Kenneth W. Bruland5, David A. Hutchins6, Steven W.
Wilhelm1,2,*
1Department of Microbiology, and
2Center for Environmental Biotechnology, The University of Tennessee, Knoxville, Tennessee 37996, USA
3Department of Biology, The University of Western Ontario, London, Ontario N6A 5B7, Canada
4Grice Marine Laboratory, College of Charleston, Charleston, South Carolina 29412, USA
5Department of Ocean Sciences, The University of California Santa Cruz, Santa Cruz, California 95064, USA
6College of Marine Sciences, The University of Delaware, Lewes, Delaware 19958, USA
*Corresponding author. Email: wilhelm@utk.edu
ABSTRACT: Studies in high nutrient, low chlorophyll (HNLC) regions have demonstrated that increased Fe availability results in an increase in phytoplankton biomass and changes in community composition. Here we present experiments in which the availability
of iron (Fe) was increased or reduced to monitor the response of individual groups of phytoplankton (large eukaryotes, picoeukaryotes and cyanobacteria) by flow cytometry. Additions (0.5 to 5.0 nM Fe) and reductions in available Fe (through addition of 1
to 10 nM of the fungal siderophore desferrioxamine B) were made to enclosed communities from the South American eastern boundary current off Peru, where ambient dissolved Fe concentrations were <100 pM. As predicted, chlorophyll concentrations
increased in the added Fe treatments relative to the control, indicative of Fe limitation. Flow cytometry demonstrated that this was due to increases in the abundance of large eukaryotes that are Fe-starved under ambient conditions. Cyanobacterial
abundance increased and decreased linearly with Fe availability, suggesting that cyanobacteria were Fe-limited but not Fe-starved. In contrast, picoeukaryote cell abundance increased with decreasing Fe availability, although chlorophyll cell-1
in this group responded in an inverse manner. The results demonstrate that members of the marine phytoplankton community respond differently to Fe availability, which may influence the outcome of biological competition among organisms in Fe-limited
environments.
KEY WORDS: Fe limitation · Fe Uptake · Desferrioxamine B · Picoeukaryotes
Full text in pdf format
Published in AME Vol.
35, No. 1
(2004) on April 2
Print ISSN: 0948-3055; Online ISSN: 1616-1564.
Copyright © Inter-Research, Oldendorf/Luhe, 2004
|
