A Method For Determining The Growth Rate Of Alkenone-Producing Microalgae In Oceanic Waters

Date
2004-12
Authors
Deschenes, Bryan R.
Contributor
Advisor
Department
Instructor
Depositor
Speaker
Researcher
Consultant
Interviewer
Annotator
Journal Title
Journal ISSN
Volume Title
Publisher
Volume
Number/Issue
Starting Page
Ending Page
Alternative Title
Abstract
Extension of atmospheric C02 records to more ancient times through the development of a geological proxy for C02 is a major objective of paleoclimate studies. A promising C02 proxy has been carbon isotopic analysis of marine organic matter (Rau et al., 1992; Hayes et al., 1990). However, recent studies have demonstrated that microalgal growth rates and cell geometry in addition to C02 concentration affect carbon isotopic fractionation in marine microalgae. Results of modeling (Rau et al., 1996, 1997) and laboratory chemostat experiments (Laws et al., 1995, 1997; Bidigare et al., 1997; Popp et al., 1998) have begun to clarify these effects. Isotopic analysis of alkenones provides a way to constrain the size and shape of the source organism because these compounds are only produced by a few select microalgae (Marlowe et al., 1990). Although laboratory and field studies suggest that isotopic analysis of alkenones shows great potential as a C02 proxy, the relationship between specific growth rate and carbon isotopic fractionation in natural samples is not well defined. This research establishes in the laboratory an alkenone BC-labeling method that can be used to evaluate the effect of growth rate on carbon isotopic fractionation in natural populations of the open ocean, alkenone-producing microalgae, Emiliana huxleyi and a major coastal variant, Isochrysis galbana. Our approach is analogous to the method for determining phytoplankton growth rates using 14C-labeling of pigments (Goericke and Welschmeyer, 1992, 1993) but uses irmGCMS to determine the rate of BC incorporation into alkenones.
Description
Keywords
Citation
Extent
Format
Geographic Location
Time Period
Related To
Theses for the degree of Master of Science (University of Hawaii at Manoa). Oceanography; no. 3914
Table of Contents
Rights
All UHM dissertations and theses are protected by copyright. They may be viewed from this source for any purpose, but reproduction or distribution in any format is prohibited without written permission from the copyright owner.
Rights Holder
Local Contexts
Email libraryada-l@lists.hawaii.edu if you need this content in ADA-compliant format.