Oysters in a Changing Ocean: Effects of acidification and warming on Olympia oyster larval swimming and growth

Anthropogenic influence and increased atmospheric CO2 are creating a myriad of changing conditions for the world's oceans, including ocean acidification and warming. Multi-stress studies are imperative to the understanding of practical ocean conditions, as often times concurrent stressors exhibit synergistic rather than additive effects on organisms. We analyzed effects of temperature and acidification on Olympia oyster, Ostrea lurida, larval swimming behavior and growth. As the only oyster native to the northern Pacific coast of North America, this species has been in decline for the past few centuries, and has been a topic of interest for restoration in recent years. We cultured larvae at three pCO2 treatments (400ppm, representative of current atmospheric CO2 measurements, 800ppm, and 1200ppm, representative of possible predicted levels within the next century) and two temperatures (12 degreesC and 25 degreesC, values nearing the low and high temperature limits of the species). We used larval tracking and video analysis techniques to quantify swimming performance, and determined growth rate using digital image evaluating software. Knowing how swimming behaviors and the duration of the planktonic life cycle change with ocean warming and acidification will give us a better understanding of larval dispersal and inform restoration efforts.