Physiological assessment of the vulnerability of estuarine and marine organisms to ocean acidification

PI: Anne Todgham


Research Institution:               San Francisco State University

PI First name, Last name:         Dr. Anne Todgham

Phone:                                     415-405-2864


Project website link:



As an environmental physiologist, my research program aims to understand how organisms respond to changes in their natural environment (e.g. increases in CO2, increases in temperature, decreases in oxygen levels) and the physiological mechanisms that allow them to tolerate these changes.  Currently, we are interested in understanding the impacts of ocean acidification (OA) as well as other environmental drivers of climate change (e.g. ocean warming) on marine ecosystem by taking a species-level approach.  We are assessing the vulnerability of estuarine and marine organisms to ocean acidification through investigations of the physiological “weak links” that underlie an organism’s inability to tolerate increases in CO2.

Our research combines field and laboratory studies and takes an integrative approach where we assess the performance of animals to environmental change from molecular (e.g. transcriptomic analysis), biochemical (e.g. metabolic enzyme activity) and whole-organism (i.e. growth, development & survival) levels.  Responses to multiple stressors are complex. Organisms may be able to adjust their physiology to cope with elevated levels of CO2 but this compensatory response could result in less energy available for mounting a stress response to further environmental change. Understanding how multiple stressors interact to shape an organism’s physiology is essential if we are to provide insight into the “winners” and “losers” of global climate change. Recent research on the impacts of ocean acidification has involved projects looking at larval development of sea urchins and oysters to conditions of elevated CO2 as well as elevated temperature based on predictions provided by the Intergovernmental Panel on Climate Change.  In collaboration with Gretchen Hofmann at UC Santa Barbara, we examined the growth and development of purple sea urchin, Strongylocentrotus purpuratus, and the painted urchin, Lytechinus pictus,  under conditions of elevated CO2 and investigated the molecular mechanisms underlying their response to these conditions (i.e. changes in the expression of genes involved in biomineralization, stress tolerance and metabolism).  In collaboration with the Bodega Ocean Acidification Research group at UC Davis’s Bodega Marine Lab (PIs Gaylord, Hill, Russell & Sanford), we are investigating the energetic costs associated with growing and developing under future ocean conditions in the native Olympia oyster, Ostrea lurida.

The ultimate goal of our research is to more broadly understand the processes and mechanisms that set limits on an animal’s capacity to tolerate changes in their natural environment.  This information will allow us to better predict shifts in animal distribution and abundance in response to climate change.

KEYWORDS:     oysters, sea urchins, environmental genomics, physiological performance, temperature, salinity, multiple stressors

 FUNDING AGENCY:     CSU Council on Ocean Affairs, Science and                                                              Technology