Production and partitioning of organic matter during simulated phytoplankton blooms Public Deposited

http://ir.library.oregonstate.edu/concern/graduate_thesis_or_dissertations/5425kd28f

Descriptions

Attribute NameValues
Creator
Abstract or Summary
  • Few studies have examined the partitioning of organic matter in upwelling systems, despite the fact that these systems play a key role in carbon and nitrogen budgets in the ocean. We examined the production and partitioning of phytoplankton-derived organic matter in deck incubations off Oregon during the upwelling season. During exponential growth of the phytoplankton, ≥ 78% of total accumulated organic matter was in particulate form. A small accumulation of dissolved organic matter (DOM) was only observed in one incubation and the percentage of daily primary production released extracellularly averaged 12.7 ± 2.75 %, suggesting that DOM is a small fraction of primary production during exponential growth of coasta1 phytoplankton blooms. Following nitrate depletion, carbon-rich (C:N ≥ 16) DOM accumulated and the percentage of daily primary production released as dissolved organic carbon (DOC) averaged 57.7 ± 10.7 %. Abundances and growth rates of bacteria with a high DNA content increased rapidly concomitant with the large DOM release, while little response was observed from bacteria with a low DNA content. Despite the enhanced bacterial growth, a net decrease in DOC was only observed in one incubation and immediately after reaching maximum abundance, high-DNA bacterial abundances declined while heterotrophic nanoflagellate abundances increased. These results indicate that both bottom- up and top- down controls may act to prevent bacterial degradation of phytoplankton DOM, thus allowing the short-term accumulation (several weeks) of C rich DOM in the Oregon upwelling system. In addition to the accumulation of C rich DOM, approximately 70 to 157% more C was fixed than would be predicted by Redfield stoichiometry based on measured concentrations of nitrate and accumulated TOC. Accumulation of C rich DOM and excess carbon fixation suggests that nitrate assimilation (i.e., new production) might not equate to net production of POM in coastal upwelling systems.
Resource Type
Date Available
Date Issued
Degree Level
Degree Name
Degree Field
Degree Grantor
Commencement Year
Advisor
Committee Member
Academic Affiliation
Non-Academic Affiliation
Subject
Rights Statement
Publisher
Peer Reviewed
Language
Digitization Specifications
  • File scanned at 300 ppi (Monochrome, 24-bit Color) using ScandAll PRO 1.8.1 on a Fi-6670 in PDF format. CVista PdfCompressor 4.0 was used for pdf compression and textual OCR.
Replaces
Additional Information
  • description.provenance : Approved for entry into archive by Patricia Black(patricia.black@oregonstate.edu) on 2011-08-09T21:26:51Z (GMT) No. of bitstreams: 1WetzMichaelS2004.pdf: 727778 bytes, checksum: d1a804ac42e9f0b83d821efe8f15a2cc (MD5)
  • description.provenance : Made available in DSpace on 2011-08-15T15:14:14Z (GMT). No. of bitstreams: 1WetzMichaelS2004.pdf: 727778 bytes, checksum: d1a804ac42e9f0b83d821efe8f15a2cc (MD5) Previous issue date: 2003-06-04
  • description.provenance : Submitted by Tamera Ontko (toscannerosu@gmail.com) on 2011-08-04T19:14:39ZNo. of bitstreams: 1WetzMichaelS2004.pdf: 727778 bytes, checksum: d1a804ac42e9f0b83d821efe8f15a2cc (MD5)
  • description.provenance : Approved for entry into archive by Patricia Black(patricia.black@oregonstate.edu) on 2011-08-15T15:14:14Z (GMT) No. of bitstreams: 1WetzMichaelS2004.pdf: 727778 bytes, checksum: d1a804ac42e9f0b83d821efe8f15a2cc (MD5)

Relationships

Parents:

This work has no parents.

Last modified

Downloadable Content

Download PDF

Items