Project: Ocean Acidification: Collaborative Research: Interactive effects of acidification, low dissolved oxygen and temperature on abalone population dynamics within the California Current

Ocean acidification is increasingly recognized as a significant driver of change in marine ecosystems. In particular, ecosystems in eastern boundary current systems, including the California Current Large Marine Ecosystem (CCLME), routinely experience upwelling driven low pH, low dissolved oxygen (DO) waters in shallow near shore habitats, and these occurrences have been increasing in magnitude and duration over the past decade.

The goal of this project is to study the consequences of ocean acidification and other climate-related changes (dissolved oxygen(DO), temperature) in oceanographic conditions on near shore marine communities over a large scale oceanographic gradient in the CCLME. Understanding how the effects of ocean acidification combined with other climate-related changes on individual marine organisms or life stages will cascade to populations and the services they provide is a high priority for science, management, and policy. By integrating the results of oceanographic field measurements and laboratory experiments in a demographic and bio-economic modeling framework, the present project will advance our understanding of the role of oceanographic variability on the dynamics of marine populations and fisheries. In particular, this research will provide key insights regarding the interactive influences of simultaneous changes in pH, DO, and temperature on nearshore populations and fisheries. By investigating the effects of multiple stressors on coastal marine ecosystems, the project will allow us to better anticipate possible ecological and fishery impacts of increasing frequency and/or intensity of low pH and low DO events. A deeper understanding of the linkages among ocean acidification, coastal oceanographic processes and the health of nearshore marine ecosystems in the CCLME will inform adaptation strategies for future ocean conditions. 

The research program will implement a novel individual- to population-level approach to specifically investigate how the direct effects of ocean acidification, alone or in combination with low DO and temperature, on two model species of great ecological and commercial relevance, red and pink abalone, will manifest at the population level, and ultimately, the services these species provide to humans. Researchers will: 1) measure and characterize the temporal variability of pH, DO and temperature in nearshore abalone habitat in Monterey Bay, Central California, and Isla Natividad, Mexico, particularly in relation to the duration and intensity of extreme low pH, low DO events, under alternative scenarios of future climate change, 2) conduct laboratory experiments to investigate the effects of low pH, low DO conditions on the reproductive success, growth, calcification, and survival of juvenile red and pink abalone, and 3) develop demographic and bio-economic models to estimate the impacts of environmental and local anthropogenic stressors on the resilience of abalone populations and to assess what management and conservation strategies, including the implementation of networks of marine reserves, may contribute to buffering the negative effects of increased frequency and/or intensity of low pH and low DO events expected under near-future climate scenarios.