Meeting Abstract
Ocean acidification has been found to affect the physiology and growth of coralline algae, which play significant functional roles in marine ecosystems worldwide. Currently there are no studies that examine the potential for local adaptation to different pCO2 conditions in this important group. In order to examine the physiological plasticity between life stages and signatures of local adaptation, we used common garden experiments to investigate how adults and spores of Corallina vancouveriensis from populations naturally exposed to different carbonate chemistry due to upwelling events responded to different pCO2 levels. Our results show that spore growth for both populations was not affected by pCO2 conditions, however adults from different sites showed distinct responses in acclimation capacity, photosynthetic performance and growth rates when exposed to higher pCO2. Growth rates of C. vancouveriensis decreased under high pCO2; however algae from the northern site showed a smaller change in size than algae from the southern site suggesting higher acclimation potential and/or local adaptation in the northern population. All adult populations showed higher respiratory rates and a significant reduction of pigment content (chlorophyll and phycobilins) after being exposed to high pCO2 levels for 30 days. Our results indicate that different life stages of C. vancouveriensis have different tolerances of high pCO2; spores showed less sensitivity to changes in the carbonate chemistry whereas adults were more sensitive. Adults from the site with more carbonate chemistry variation showed both higher tolerance and greater acclimation potential.
