Meeting Abstract
The earth’s oceans are becoming more acidic due to absorption of atmospheric CO2. Ocean acidification decreases the concentration of carbonate ions in seawater, and imposes increased energy costs on organisms that deposit calcium carbonate shells and skeletons. Larval stages of these organisms are especially vulnerable to stresses of acidification and nutrition, which may have a common energetic basis. We investigated how acidification and nutrition affected precompetent larval growth of the slipper limpet Crepidula fornicata during the first 8 d after hatching. We also asked if a 4 d period of food and/or acidification stress, applied to older competent larvae, affected speed of metamorphosis and juvenile growth after stresses were relieved. Treatments in both experiments used all 4 combinations of pH 7.8 or 7.4, and high or low food (15×104 or 1×104 cells/ml Isochrysis galbana). pH setpoints were achieved by bubbling CO2 in 0.2 μm-filtered seawater. Lower food level in the pH 7.8 treatments resulted in decreased growth rates for precompetent larvae (p<0.0001), while larvae failed to grow in the pH 7.4 treatments regardless of food level. Increased acidification extended the latency of KCl-induced metamorphosis in the second experiment (p<0.04), but nearly all larvae completed metamorphosis within 24 h. Juveniles were then held at ambient pH of 7.8-8.1 while being fed 10×104 cells/ml I. galbana. Together, larval experience of acidification and low food availability decreased subsequent juvenile growth in the first 6 d after metamorphosis (p<0.01), demonstrating carryover effects of larval experience on juvenile performance.
