Rising atmospheric levels of CO2 are expected to lead to substantial lowering of ocean pH within the next century. Impacts of ocean acidification (OA) are being intensively studied at FHL and at other laboratories around the world, particularly with respect to organisms that make calcareous skeletons that become more difficult to grow and maintain in acidified conditions.
Many studies have focused on veliger larvae of molluscs, because of the ecological and economic importance of these animals. Although many studies have documented OA effects on larval growth and survival, few have focused attention on the critical life history transition of metamorphosis, when pelagic larvae become benthic juveniles. This is a pressing area for research, in two respects. First, it is clear that larval experience may have profound latent effects on juveniles (1). Second, developmental effects of OA occur in the context of other influences such as nutrition, salinity, and temperature, so it is necessary to study such interactions (2).
In the summer of 2017 we will study interactions of OA and other environmental variables in larvae and juveniles of the gastropod, Crepidula fornicata. How do these factors affect the acquisition of competence for metamorphosis, larval behaviors that are related to settlement and metamorphosis, and post-metamorphic juvenile performance? C. fornicata is an ideal animal for this research. Much baseline information is already known about its development, metamorphosis, and life history. The veligers are large (up to 1.5 mm), easily cultured, and amenable to ecologically-relevant behavioral and neurophysiological experiments (3).
Furthermore, C. fornicata is native to the eastern U.S. but has become established as a non-native species in many parts of the world (including Washington), and is of great interest as an invasive species in changing ecosystems (4). In this project students will learn elements of experimental design, as well as methods of larval culture, carbonate chemistry, metamorphosis assays, and techniques for analysis of larval behavior.
(1) Pechenik JA (2006) Integr Comp Biol 46: 323-333.
(2) Byrne M, Przeslawski R (2013) Integr Comp Biol 53: 582-596.
(3) Penniman JA et al. (2013) Invertebr Biol 132: 14-26.
(4) Bohn K, Richardson C (2012) Mar Biol 159: 2091-2103.