Thursdays, 4:30–5:30 pm
6 January–10 March 2011
School of Aquatic & Fishery Sciences
102 Fishery Sciences (auditorium)
1122 NE Boat Street (map)
University of Washington
Reception follows each talk

For more information, contact:
Trevor Branch, 206-221-0776
tbranch@u.washington.edu
courses.washington.edu/susfish

Funding for the Series is generously
provided by Tanya Bevan, friends of Don
Bevan, the UW School of Aquatic and
Fishery Sciences, and NOAA's Alaska
Fisheries Science Center and
Northwest Fisheries Science Center.

Ocean Acidification: Effects on Fisheries and Oceans

24 Feb Gretchen Hofmann

Gretchen Hofmann

Professor, Department of Ecology, Evolution and Marine Biology, UC Santa Barbara

Individual Responses to Acidifying Oceans: Migration, Acclimation, Adaptation, or Death

Abstract

Coastal marine ecosystems, from the intertidal to the continental shelves, are particularly vulnerable to global climate change (IPCC 2007) and the physical factors that are changing in these systems are more than just temperature. Due to the interaction of oceans with the atmosphere and the role of the ocean in carbon dioxide (CO2) sequestration, marine ecosystems will experience temperature changes combined with changes in ocean pH (aka ocean acidification). Thus, as a consequence of future elevated levels of the greenhouse gas, CO2, the predictions for our coastal ocean is a complex and different seawater chemistry that is most likely a new environmental experience for most marine organisms. Notably, processes such as biomineralization (the production of calcium carbonate shells and skeletons) will be impacted, but other basic metabolic activity may also be challenged. This presentation will explore what we know now about how organisms might respond to climate-change related “multistressors” in the future high CO2 world.

Bio

Dr. Gretchen Hofmann is an eco-physiologist whose research focuses on the effects of climate and climate change on the performance of marine species. In particular, her recent work investigates the impact on marine organisms of rising atmospheric CO2 concentrations via global warming and ocean acidification. Dr. Hofmann studies how such environmental changes influence the regulation of mechanisms within the body that impact development, geographic distribution and survival.

To study the effects of temperature on physiological performance Dr. Hofmann has conducted research at broad geographic scales examining species across climates, information which may also be used as a proxy for predicting the response of organisms in one location through time under climate change scenarios. She has also done extensive work in Antarctica studying marine fishes and invertebrates that are highly evolved to polar climates and may be particularly sensitive to global warming. Her research has explored the specific temperature responses of these polar organisms, and identified physiological mechanisms which these and other more temperate species may employ in response to thermal stresses in their environments.

Dr. Hofmann is also involved in research on ocean acidification, or the gradual reduction in ocean pH by the seawater’s uptake of atmospheric CO2. Recent government reports project ocean acidification to increase over the next century and have significant impacts on shell-forming organisms as they build and maintain their hard structures. However the overall physiological response that organisms will have under these “acidified” seawater conditions is still being determined. Studies by Dr. Hofmann and her collaborators are identifying key developmental challenges for the sensitive larval stages of marine species in acidified waters, and gene pathways that may play a role in those processes. She is also investigating the combined effects of temperature and acidity, in order to better understand how marine species will cope with the dual challenges of global warming and ocean acidification in the coming century.

Readings