Meeting Abstract
It is theorized that ocean acidification (OA) will have significantly higher impacts on early life stages teleost due to their lack of well-developed acid-base machinery. Estuaries are dynamic environments that undergo fluctuations in environmental parameters. Specifically, we have documented changes in pH over daily, seasonal, and yearly time scales. This led us to believe that estuaries may be a source of resilient genotypes for OA. Here we provide evidence of resilience of two different estuarine species with different life histories. Sciaenops ocellatus, which are native to the West Atlantic and Caribbean, are fast developing and are rapidly integrated into the estuarine environment. Epinephelus coioides, which are native to the Indo-West Pacific, are also fast developing but have a delayed integration into the estuarine environment. We hypothesized that due to the delayed migration into the estuary that early life stage E. coioides would be more severely impacted by increases in CO2 exposure, while S. ocellatus would be more resilient. Our results indicate that both species are resilient to OA. We observed no alteration to survival, length, and yolk size at increased exposure in E. coioides, but we did observe a significant increase in heart rate at 3000 µatm. Similar patterns were observed in S. ocellatus, with no significant change in length and yolk depletion rate, but a significant change in heart rate and survival at 3000 µatm. This tolerance may be related to early induction of acid-base balance pathways as gene expression of major acid-base transporters peaks at 16 hours post-fertilization for S. ocellatus, which is coincident with the presence of epithelial ionocytes.
