Meeting Abstract

P2.24  Saturday, Jan. 5  Physiological cost of future ocean conditions on larval development in the native Olympia oyster, Ostrea lurida. BOLES, S.E*; HETTINGER, A; GAYLORD, B; SANFORD, E; TODGHAM, A.E; San Francisco State University; Bodega Marine Laboratory, Univ. of California, Davis; Bodega Marine Laboratory, Univ. of California, Davis; Bodega Marine Laboratory, Univ. of California, Davis; San Francisco State University ponettie@mail.sfsu.edu

Since the Industrial Revolution, roughly 48% of anthropogenic CO₂ has been absorbed by the oceans, causing a reduction in pH of 0.1 units, and a further decrease of 0.3-0.4 pH units is expected by the end of this century. A great deal of research has been done to predict the future impacts of ocean acidification (OA) on calcifying organisms; however, studies examining the synergistic effects of OA and global warming on the physiological and biochemical processes during early development of calcifying animals are unclear and require further analysis. We reared larvae of the native Olympia oyster, Ostrea lurida, under a factorial combination of CO₂ (control, 385ppm vs. elevated, 1000ppm) and water temperature (control, 20°C vs elevated, 24°C). To evaluate the energetic costs associated with growth and development under these treatments, we assessed enzyme activity of the Krebs cycle, a proxy for aerobic metabolism. To further investigate cellular transcriptional activity under experimental conditions, RNA to DNA ratios were measured. Larvae reared under conditions of elevated CO₂ could face higher energetic demands, leaving less energy available for biomineralization and growth. This in turn could leave less energy available for coping with thermal stress (e.g. ocean warming as well as highly variable thermal habitat of the intertidal zone), possibly impeding survival and settlement of O. lurida. With global climate change, a plethora of environmental factors are predicted to undergo relatively rapid changes; therefore it is pertinent to understand the impacts of climate change from a multi-stressor perspective.