Meeting Abstract

73-2  Saturday, Jan. 7 08:15 – 08:30  The Effects of Elevated pCO₂, Hypoxia and Temperature on Larval Sheepshead minnow, Cyprinodon variegatus: How much stress is too much? ENZOR, LA*; MOSO, E; HANKINS, C; BARRON, MG; US Environmental Protection Agency; US Environmental Protection Agency; US Environmental Protection Agency; US Environmental Protection Agency enzor.laura@epa.gov

Estuarine fish are acclimated to living in an environment with rapid and frequent changes in temperature, salinity, pH, and dissolved oxygen (DO) levels; the physiology of these organisms is well suited to cope with extreme thermal, hypercapnic, and hypoxic stress. While the adverse effects of low dissolved oxygen levels on estuarine fish has been well-documented, the interaction between low DO and elevated pCO₂ is not well understood. There is some evidence that low DO and elevated pCO₂ interact antagonistically, however little information exists on how projected changes of pCO₂ levels in near-shore waters may affect estuarine species, and how these changes may specifically interact with dissolved oxygen and temperature. We explored the survivability of 7-day post fertilization sheepshead minnow, Cyprinodon variegatus, using short term exposure to the combined effects of elevated pCO₂ (~1300 µatm; IPCC RCP 8.5) and low dissolved oxygen levels (~2 mg/L). Additionally, we determined if the susceptibility of these fish to elevated pCO₂ and low DO was influenced by increases in temperature from 27.5°C to 35°C. Results from this study and future studies will be used to identify estuarine species and lifestages sensitive to the combined effects of elevated pCO₂ and low dissolved oxygen.