Effects of varied pCO2 on Atlantic Surf Clams ; Culture Experiments

The concentration of carbon dioxide in the atmosphere is rapidly increasing, primarily as a result
of fossil fuel use and other human activities. This increase in atmospheric CO2 is driving a flux
of CO2 into the oceans, where the carbon dioxide forms carbonic acid and lowers the pH of
seawater, a process known as ocean acidification (OA). There is evidence that this drop in
seawater pH may impact a range of biological processes in the oceans, including calcification
(e.g., shell formation and reef building), and perhaps larval development in both calcifying and
non-calcifying species. However, these biological effects are not yet well understood, and are
likely to vary from species to species. We propose to use our CO2 enrichment culturing facilities
(in the Marine Calcification Laboratory at WHOI), carbonate system analytical capabilities (in
co-PI McCorkle’s lab), and microscopic imaging and image analysis capabilities (in co-PI
Cohen’s lab), to carry out two ocean acidification experiments on the Atlantic surf clam, Spisula
solidissima. These experiments will be carried out in collaboration with colleagues at the NMFS
laboratory in Milford CT (Drs. Lisa Milke and James C. Widman), who have considerable
expertise in the physiology and development of S. solidissima. A short-term experiment (2-3
days post-fertilization) will investigate the impact of elevated pCO2 on larval development and
initial calcification, and a longer-term experiment (21 days) will investigate OA impacts on surf
clam development through metamorphosis.