Ocean acidification has subtle and complicated effects on fish because it often affects only the earliest life stages and interacts with other stressors. This project pulled together several types of data from multistressor experiments on Atlantic silversides, an abundant fish along the East Coast, to model their energy budget throughout the life cycle. Using Dynamic Energy Budget theory (DEB) we are able to incorporate different effects at each life stage to reflect the increased tolerance adults have relative to embryos and larvae. Energy budgets can help us test hypotheses about how energy is allocated to needs like homeostasis and reproduction under acidification, and ultimately estimate population-level effects.

We previously investigated the molecular mechanisms associated with resilience to ocean acidification in Crassostrea virginica. There were significant differences in SNP and gene expression profiles among oysters reared under normal and OA conditions. Both of these approaches showed similar results, particularly in genes related to biomineralization, including perlucin. In this study, we used RNAi or gene silencing to validate findings and confirm the protective role of perlucin associated with resilience to OA. Silenced oysters under acidification stress were the smallest, had shell abnormalities, and had significantly reduced shell mineralization, thereby indicating that perlucin does help larvae mitigate the effect of OA.

Better understanding the carbonate system variability during extreme events will help predict future changes and provide critical information for the local shellfish aquaculture industry. In this study, a coupled hydrodynamic-biogeochemical 3-D high-resolution model is used to investigate the primary controls of the carbonate system in a small sub-estuary of the Chesapeake Bay: the York River Estuary. Net horizontal advection, air-sea CO2 flux, and net community production all play crucial roles in controlling dissolved inorganic carbon (DIC) and pH, while total alkalinity is relatively conservative. During extreme high discharge events, pH reductions are associated with net heterotrophy and net advection of high DIC upstream water, with increased outgassing playing a counteracting role.

Currently, productive coastal systems lack vertically-resolved high-resolution ocean carbonate system measurements on timescales relevant to organism ecology and life history. To address this issue, a newly developed deep ISFET (Ion Sensitive Field Effect Transistor)-based pH sensor system was modified and integrated into a Slocum G2 profiling glider. From Spring 2018 to Fall 2019, seasonal pH glider deployments were conducted in Atlantic surfclam (Spisula solidissima) and Atlantic sea scallop (Placopecten magellanicus) commercial management zones in the Mid-Atlantic Bight. Here, we present seasonal cycles and drivers of carbonate chemistry in the Mid-Atlantic Bight based on seasonal glider deployments. Additionally, we discuss the use of glider data in conjunction with larval dispersal models to identify times and locations where shellfish stock may be at high risk of acidification.