Elucidating the Role of Ocean Acidification in Estuarine Phytoplankton Dynamics

EPA Grant Number: F13E20884
Title: Elucidating the Role of Ocean Acidification in Estuarine Phytoplankton Dynamics
Investigators: Golda, Rachel
Institution: Oregon Health & Sciences University
EPA Project Officer: Lee, Sonja
Project Period: September 29, 2014 through September 29, 2016
Project Amount: $84,000
RFA: STAR Graduate Fellowships (2013) RFA Text |  Recipients Lists
Research Category: Fellowship - Environmental Science and Engineering , Academic Fellowships


Increased stress resulting from environmental pressures has been shown to increase toxin production in harmful marine algae. This project utilizes a novel autonomous algal culturing system to study the effect of the emerging environmental stressor of ocean acidification on algal toxin production and to determine what drives these effects on an intracellular level.


A novel autonomous pHstat/chemostat system will be designed and built to mimic the conditions of ocean acidification in a laboratory environment. The pHstat will maintain varying degrees of environmental acidity for extended periods of time, allowing determination of possible long-term ecosystem effects. Relationships between algal toxin levels and cell stress, and between toxin levels and environmental acidity, will be identified. The effects of environmental acidity on cellular processes and reproduction also will be determined, which will elucidate how this relates to toxin production.

Expected Results:

Increased algal toxin production has been related to physiological stress induced by environmental pressures. Increased environmental acid-
ity, such as that which is exhibited during ocean acidification, has been shown to cause stress in a number of marine microbes. It is therefore likely that increased ocean acidity will cause a concurrent increase in algal toxin production. As a measure of acidity, pH has been shown to exert direct control on the cell cycle of all living creatures. Toxin production in algae has been directly linked to the cell cycle. It is therefore likely that ocean acidification exerts a damaging effect on organisms at the intracellular level and can directly influence the behavior of the organism by controlling progression of the cell cycle and, thus, cellular processes and reproduction.

Potential to Further Environmental/Human Health Protection

Knowledge gained from this research may be used to develop predictive models of algal toxin distribution in coastal environments. This research also can be used to elucidate previously unknown collateral damage of interactions between emerging environmental problems. This knowledge will allow ecosystem managers to take a more aggressive approach in limiting human exposure to algal toxins, and it will be of great use to policymakers in assessing environmental and human health risks associated with emerging environmental problems.

Supplemental Keywords:

chemostat, harmful algal blooms, ocean acidification

Progress and Final Reports:

  • 2015
  • Final