Project: Effects of Ocean Acidification on Larval Competence, Metamorphosis, and Juvenile Performance in a Planktotrophic Gastropod

Extracted from the NSF award abstract:

This study examines how OA under different environmental conditions will impact the development, dispersal, and metamorphosis of the marine snail Crepidula fornicata, a common species native to the eastern U.S. that has now become established in the Pacific Northwest, Europe, and elsewhere. This study will include: 1) the impact of OA on relative rates of tissue and shell growth in larvae; 2) long-term impact of larval exposure to OA on the survival and growth of juveniles; 3) influence of OA on gene expression patterns in both larvae and juveniles; 4) impact of OA on time until metamorphosis and on the ability to metamorphose in response to environmental inducers; 5) effect of elevated temperature on responses to OA; 6) impact of larval diet on vulnerability to OA; and 7) impact of OA on larval swimming ability and settlement behavior. 

Molluscan larvae are expected to be especially susceptible to the effects of ocean acidification (OA) in the coming years, due to their thinly calcified shells. In addition, water temperatures are expected to amplify some impacts of OA. Some effects, such as potentially reduced growth rates, reduced shell thickness, and altered dispersal capability are likely to be immediate, while others (latent effects) may appear only later in development, well after metamorphosis has taken place. In addition, OA--with or without ocean warming--may alter larval behavior and physiology in ways that affect the timing of metamorphosis and the fitness of juveniles,thus altering dispersal potential and vulnerability to predators. OA may also alter the abundance and nutritional quality of phytoplankton. We will investigate the consequences of OA under different environmental scenarios for larvae of the marine gastropod Crepidula fornicata, an easily cultured species that is receiving increasing attention both as a general model for lophotrochozoan development and as an ecologically significant invader in benthic subtidal communities. Our study will include: 1) impact of OA on rates of larval tissue and shell growth; 2) latent effects of larval exposure to OA on juvenile survival and growth; 3) effect of elevated temperature on responses to OA; 4) influence of elevated OA on larval and juvenile gene expression; 5) impact of OA on the development of competence for metamorphosis; 6) impact of OA on the response of competent larvae to a variety of metamorphic inducers; 7) impact of larval diet quality on vulnerability to OA, both in the larval stages and following metamorphosis (latent effects); and 8) impact of OA on larval swimming and settlement behaviors, and the neural correlates of those behaviors.