Meeting Abstract

46.3  Saturday, Jan. 5  Multiple climate change variables interact to reduce the physiological performance of sea urchin larvae in future oceans PADILLA-GAMINO, JL*; KELLY, MW; EVANS, TG; HOFMANN, GE; University of California, Santa Barbara; University of California, Santa Barbara; University of California, Santa Barbara; University of California, Santa Barbara gamino@lifesci.ucsb.edu

In marine environments, ocean warming and ocean acidification, both consequences of anthropogenic production of CO₂, will combine to influence the physiological performance of species. In this study, we used an integrative approach to forecast the impact of future ocean conditions on larval purple sea urchins (Strongylocentrotus purpuratus) from an area of the Northeast Pacific Ocean already affected by climate change. In laboratory experiments that simulated ocean warming and ocean acidification, we examined larval development, skeletal morphology, metabolism and genome-wide expression under four different temperature (13°C and 18°C) and pCO₂ (400 and 1100 μatm) regimes. Ocean warming and ocean acidification have both singular and synergistic effects on the performance of early life stages of S. purpuratus. Simultaneous exposure to increased temperature and pCO₂ significantly reduced larval metabolism and triggered a widespread down-regulation of histone encoding genes. pCO₂ but not temperature impaired calcification and reduced the expression of a major spicule matrix protein, suggesting that calcification will not be further inhibited by ocean warming. Importantly, shifts in skeletal morphology were not associated with developmental delay. Collectively, our results indicate that climate change variables will interact to exceed thresholds for optimized physiological performance in this key marine species.