EAPSI: Determining the Impacts of Ocean Acidification on Fish Species that Live in Dynamic Estuaries

Lonthair Joshua K, Port Aransas TX

Investigators

Abstract

Ocean acidification (OA) is known to have many detrimental impacts on marine fish species, with early life stages being particularly susceptible. These findings have brought renewed focus onto physiological traits in early development that may bestow resilience to OA. Acid-base balance is one such pathway. This project will investigate the impacts of ocean acidification on the acid-base physiology of early life stage orange-spotted grouper (Epinephelus coiodes), which is a popular commercial fish throughout Asia and inhabits estuaries during early life stages. Estuarine fish have been underrepresented in OA research, yet these animals regularly experience CO2 levels in excess of those predicted for climate change. We predict that estuarine fish, such as the spotted grouper, may be pre-adapted for resilience against OA. The research will be conducted with Dr. Pung-Pung Hwang, a noted faculty member in the field of fish molecular and integrative physiology, at Academia Sinica in Taipei, Taiwan. This study will investigate the development and plasticity of acid-base physiology in early life stages of the orange-spotted grouper. Early life stage studies are critical for understanding the impacts of OA on commercial fisheries because this represents a bottleneck to recruitment from early life stages to reproductive adults. Sensitivity to OA will be measured via analysis of survival, yolk size and standard length, as a consequence of elevated CO2. Acid-base development will be analyzed by measuring gene expression of key proteins over time and under varying CO2 concentrations. In situ hybridization and immunofluorescence microscopy will subsequently determine the location of gene or protein expression. Together these studies will determine the sensitivity of orange-spotted grouper to OA and the role of acid-base physiology in conferring early life resilience. This award under the East Asia and Pacific Summer Institutes program supports summer research by a U.S. graduate student and is jointly funded by NSF and the Ministry of Science and Technology of Taiwan.