NOAA Study Shows Summer Flounder Harmed by Ocean Acidification
Research at the Northeast Fisheries Science Center’s Sandy Hook Ocean Acidification Laboratory focuses on exploring the response of marine fishes to increased CO2. A recently published manuscript led by Dr. Chris Chambers found that exposure to ocean acidification conditions alters survival, growth, and development in early life stages of summer flounder (Paralichthys dentatus), an ecologically and economically important member of the mid-Atlantic marine and estuarine ecosystem. In the studies presented in this manuscript, eggs and larvae were exposed to three CO2 treatments chosen to resemble current and expected future CO2 conditions in coastal estuaries in the U.S. northeast: 775 µatm (pH 7.8), 1,808 µatm (pH 7.5), 4,714 µatm (pH 7.1). Exposure to the two high CO2 treatments reduced egg survival to hatch by 52% in the intermediate treatment and 84% in the high CO2 treatment. While larval survival was similar among the three CO2 treatments, larval development, morphology, and growth rates changed, with larvae from the highest CO2 treatment metamorphosing into the juveniles earlier, but at smaller sizes. Larval in both high CO2 treatments had organ damage in their liver, skin, and trunk muscles. This study highlights that different life stages of the same species may respond differently to ocean acidification. The CO2 effects on larval size, condition, and developmental rates were more subtle than the survival effect on eggs, and were revealed only through a holistic multivariate approach to characterizing species response.
The results of this study highlight the importance of examining other natural or human-induced factors that can affect an organism’s response to changes in pH, while also considering a species’ ability to adapt to these changes. Although the direct effects of ocean acidification on the physiological parameters of larval walleye pollock measured in this study were minimal, this critical resource species may be indirectly impacted by the responses of their food sources (i.e. krill, zooplankton, and other crustaceans) to high CO2 conditions. These impacts will likely be important factors in dictating future pollock populations, one of the largest single-species fisheries in the U.S.
This research was funded by the Pollock Conservation Cooperative Research Center, the Rasmuson Fisheries Research Center, Oregon State University’s Hatfield Marine Science Center, and NOAA's Alaska Fisheries Science Center and Ocean Acidification Program.