EMBRACE-OCE-Seed - Carbonate chemistry controls on shell formation in tropical marine bivalves

Shell forming species, such as bivalves, are ecologically and economically important components of marine ecosystems. However, their ability to form shells is vulnerable to shifts in seawater carbonate chemistry such as those resulting from ocean acidification (OA), caused by increased atmospheric carbon dioxide dissolving into seawater to lower pH and shift the other components of the carbonate system.

The relationships among the many components of the carbonate system can further change in coastal regions where processes like freshwater runoff and biological metabolism can modify chemistry. This challenges efforts to predict how OA might impact shell forming species living in these coastal ecosystems. These experiments will identify which carbonate system parameter, or combination of parameters, is the driver of observed sensitivity to changes in environmental chemistry and will enable better predictions of the impacts of climate change on these species.

This project will also support outreach activities that include teaching about the effects of OA on marine organisms and training for a graduate student and several undergraduate students working on addressing the relationships between marine organisms and seawater chemistry.

This project will characterize organismal responses to each component of the carbonate system. These types of experiments have been conducted in other species; however, this approach has not yet been completed for tropical bivalves. In this project, we will conduct short-term incubations of bivalves found in the tropics with the goal of identifying the carbonate system parameter(s) that most drive shell formation.

We will also conduct longer term experiments to determine whether exposure to high carbon dioxide concentrations changes which carbonate system parameters best predict shell formation rates. The proposed species encompass two species naturally occurring in the tropics including one that hosts photosynthetic symbionts. The other two species originate from temperate regions but have been introduced to the tropics by humans via aquaculture.

This project will be conducted partly at the State University of New York, College of Environmental Science and Forestry and partly at the University of Hawai’i, Hilo. Results from this project will reveal the diversity of calcification mechanisms by exploring the shell formation processes in tropical bivalve particularly in the context of ocean acidification.

This work will allow better predictions of when and where species will be most impacted by the consequences of climate change and extreme events to prioritize conservation efforts.

This award reflects NSF's statutory mission and has been deemed worthy of support through evaluation using the Foundation's intellectual merit and broader impacts review criteria.