Award: OCE-1635423

Ocean acidification (OA) currently threatens coastal marine ecosystems. The goal of this research was to develop a deeper understanding of how oysters respond to OA across a generation. We discovered that adult oysters can withstand extreme ocean acidification by altering gene expression in the mantle tissue, the chemistry of the fluid where the shell is made, as well as the elemental ratios of the shell itself. We also discovered that parental exposure to OA mitigated the response of their offspring to OA, which suggests non-genetic (e.g., epigenetic) inheritance. To test whether epigenetic inheritance was responsible for this observation, we measured DNA methylation in adult oysters and their offspring. We found that DNA methlyation was significantly altered in the gametes of parents, and could be a mechanism responsible for the intergenerational response we observed. Transgenerational effects, mediated by the epigenetic system of DNA methylation, may help mitigate the negative effects of ocean acidification on oysters. Our Epigenetics to Ocean (E20) Broader Impacts program trained 7 graduate students, 3 postdocs, 1 community college student, and 4 high school student interns in methods related to oyster husbandry and breeding, larvae phenotyping, bioinformatics, biostatistics, morphometrics, biomineralization, and biogeochemistry. In addition, we reached 7 K-12 Teachers and dozens of high school students from environmental justice communities in the North Shore Boston area through our annual workshops for high school girls. Teaching activities based on this research are freely available online. Last Modified: 04/01/2021 Submitted by: Kathleen E Lotterhos