Type
Text
Type
Thesis
Date
2009-08-01
Keywords
Dinoflagellates -- New York (State) -- Long Island | Cochlodinium polykrikoides
Language
en_US
Source
This work is sponsored by the Stony Brook University Graduate School in compliance with the requirements for completion of degree.
Identifier
http://hdl.handle.net/11401/70847
Publisher
The Graduate School, Stony Brook University: Stony Brook, NY.
Format
application/pdf
Abstract
The harmful dinoflagellate Cochlodinium polykrikoides is well known for forming ichthyotoxic blooms in coastal regions of Asia and North America, but the nutritional factors supporting and promoting these blooms have not been well studied. To better understand the nutritional ecology of the harmful dinoflagellate blooms caused by Cochlodinium polykrikoides in Long Island estuaries (NY, USA), laboratory and field studies of this species were conducted. I documented the spatial and temporal dynamics of nutrients, C. polykrikoides cells, and co-occurring phytoplankton within two New York estuaries from 2006 - 2008. I quantified the growth response of C. polykrikoides and co-occurring phytoplankton during experimental enrichment of different nitrogen sources. Furthermore, I quantified growth rates of C. polykrikoides clonal isolates on a variety of nitrogen sources (urea, ammonium, glutamic acid, nitrate) and over a range of concentrations (2-200 µM). Finally, I quantified the uptake rates of various N compounds in both field and laboratory conditions using 15N-enriched compounds. C. polykrikoides cultures grown on glutamic acid displayed significantly faster growth and N-uptake rates compared to cultures grown on urea, ammonium, and nitrate. From 2006 – 2008, blooms of C. polykrikoides occurred in regions with a variety of N concentrations, but were only monospecific (in the >20 µm size range) when concentrations of nitrate and ammonium were < 2 µM. During blooms, the addition of a variety of N compounds (urea, ammonium, glutamic acid, nitrate) significantly increased the growth of C. polykrikoides more frequently than other phytoplankton groups suggesting blooms were N-limited. Finally, the dominant N compounds assimilated by bloom communities differed among sites, with nitrate and nitrite being taken up fastest at the most eutrophic locations and urea and glutamic acid being assimilated quickest at mesotrophic sites. The sum of these observations suggests that C. polykrikoides is a nutritionally flexible species, capable of assimilating a variety of N compounds, with the compound yielding maximal growth or uptake depending on prevailing nutrient iv conditions. Results further suggest monospecific blooms may be promoted by modest levels of labile N compounds (2 – 10 µM).
Recommended Citation
Burson, Amanda Merle, "The Role of Nitrogenous Nutrients in the Occurrence of the Harmful Dinoflagellate Blooms Caused by Cochlodinium polykrikoides in Long Island Estuaries (NY, USA)" (2009). Stony Brook Theses and Dissertations Collection, 2006-2020 (closed to submissions). 58.
https://commons.library.stonybrook.edu/stony-brook-theses-and-dissertations-collection/58