The effects of temperature, CO2, and nitrogen source on the growth and physiology of the raphidophytes Heterosigma akashiwo and Chattonella subsalsa
| Author(s) | Salvitti, Lauren | |
| Date Accessioned | 2011-03-01T01:16:41Z | |
| Date Available | 2011-03-01T01:16:41Z | |
| Publication Date | 2010 | |
| Abstract | During the past three decades the frequency and duration of harmful algal blooms (HABs) have significantly increased causing major economical losses world wide as well as being identified as the cause of a number of human health illnesses. These impacts have brought harmful algal species to the forefront of research efforts which are focused primarily on the effects of abiotic and biotic factors on algal growth. Less effort has been placed on understanding how changes in environmental parameters may impact harmful algal physiology. The effects of elevated CO2 and temperature were studied using the raphidophytes Chattonella subsalsa and Heterosigma akashiwo isolated from the Delaware Inland Bays (DIB), and a cold water isolate of H. akashiwo from Puget Sound, WA. Neither increases in temperature, CO2, or a combined treatment of elevated temperature and CO2, had any significant effect on the growth rates of all three isolates. However, significant changes in physiology and carbon uptake were seen among temperature/CO2 treatments and between strains. Both isolates of H. akashiwo exhibited changes in light harvesting capabilities in response to temperature, with a decrease in maximum carbon assimilation occurring in the cold water isolate. In contrast both elevated temperature and CO2 altered the physiology of C. subsalsa although changes were not additive. Carbon assimilation increased in response to elevated CO2 while temperature had a greater effect on light harvesting in this species. While growth and cell size did not change across any treatments in these raphidophytes, the large draw down of pCO2 measured suggests that they could possibly be storing carbon, or releasing it as dissolved organic carbon. Thus, while the bloom dynamics of these HAB species will most likely not change with the predicted increases in global atmospheric carbon or temperature, a potential for them to alter phytoplankton community succession through changes in abiotic conditions remains a possibility. | en_US |
| Advisor | Warner, Mark E. | |
| Degree | M.S. | |
| Department | University of Delaware, Department of Marine Science and Policy | |
| URL | http://udspace.udel.edu/handle/19716/5817 | |
| Publisher | University of Delaware | en_US |
| dc.subject.lcsh | Raphidophytes -- Growth | |
| dc.subject.lcsh | Raphidophytes -- Physiology | |
| dc.subject.lcsh | Raphidophytes -- Effect of temperature on | |
| dc.subject.lcsh | Carbon dioxide -- Physiological effect | |
| dc.subject.lcsh | Nitrogen -- Physiological effect | |
| Title | The effects of temperature, CO2, and nitrogen source on the growth and physiology of the raphidophytes Heterosigma akashiwo and Chattonella subsalsa | en_US |
| Type | Thesis | en_US |