Meeting Abstract

P1.51  Monday, Jan. 4  Studies of ocean acidification: the physiological response of marine larval snails to elevated CO₂ ZIPPAY, M.L.*; HOFMANN, G.E.; Univ. of California, Santa Barbara; Univ. of California, Santa Barbara zippay@lifesci.ucsb.edu

Over the last 200 years, the ocean has been a sink for atmospheric carbon dioxide (CO₂) and has absorbed approximately 50% of emitted, anthropogenic CO₂. As atmospheric CO₂ continues to rise in the future, oceanic pH is predicted to decrease by an additional 0.2-0.3 unit (from pH 8.1 to an average of 7.9-7.8); this condition is known as ocean acidification (OA). A growing body of research on calcifying marine invertebrates suggests that OA can have a deleterious effect on development and various physiological processes in these organisms. In laboratory experiments designed to mimic seawater chemistry in future oceans, we examined the effects of elevated CO₂ on larvae of two marine snails, (Nucella ostrina and Haliotis rufescens). Larva were raised in culture under control conditions and two experimental CO₂ levels. These levels span the range of current atmospheric CO₂ levels (385 ppm) to a “worst case” scenario (~900 ppm) predicted for the year 2100. Following development under conditions of ocean acidification, we measured larval thermal tolerance, shell integrity and shell formation. Our results showed elevated CO₂ did not influence veliger thermal tolerance for either species. In addition, shell strength in Nucella ostrina veligers and gene expression patterns for genes involved in shell formation in abalone larvae were not changed. These results suggest that larval forms of these species may have the capacity to withstand environmental change. Supported by a Coastal Environmental Quality Initiative Graduate Fellowship (UC Marine Council) to MLZ.