Abstract. Ocean acidification (OA) is expected to have a major impact on marine species, particularly during early life-history stages. These effects appear to be species specific and may include reduced survival, altered morphology, and depressed metabolism. However, less information is available regarding the bioenergetics of development under elevated CO2 conditions. We examined the biochemical and morphological responses of Strongylocentrotus purpuratus during early development under ecologically relevant levels of pCO2 (365, 1030, and 1450 atm) that may occur during intense upwelling events. The principal findings of this study were (1) lipid utilization rates and

protein content in S. purpuratus did not vary with pCO2; (2) larval growth was reduced at elevated pCO2 despite similar rates of energy utilization; and (3) relationships between egg phospholipid content and larval length were found under control but not high pCO2 conditions. These results suggest that this species may either prioritize endogenous energy toward development and physiological function at the expense of growth, or that reduced larval length may be strictly due to higher costs of growth under OA conditions. This study highlights the need to further expand our knowledge of the physiological mechanisms involved in OA response in order to better understand how present populations may respond to global environmental change.

Reference: Biol. Bull. 223: 312–327. (December 2012)

© 2012 Marine Biological Laboratory

PAUL G. MATSON1, PAULINE C. YU1, MARY A. SEWELL2, AND GRETCHEN E. HOFMANN1,*

1Department of Ecology, Evolution and Marine Biology, University of California Santa Barbara, Santa

Barbara, California 93106-9620; and 2School of Biological Sciences, University of Auckland, Private

Bag 92019, Auckland 1142, New Zealand