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Juvenile Antarctic Rockcod Growing Up in CO2-Acidified Seawater

Paper Reviewed
Davis, B.E., Miller, N.A., Flynn, E.E. and Todgham, A.E. 2016. Juvenile Antarctic rockcod (Trematomus bernacchii) are physiologically robust to CO2-acidified seawater. Journal of Experimental Biology 219: 1203-1213.

Introducing their work, Davis et al. (2016) state that they "evaluated aspects of aerobic metabolism and cardiorespiratory physiology of juvenile emerald rockcod, Trematomus bernacchii, an abundant fish in the Ross Sea, Antarctica, to elevated partial pressure of carbon dioxide (PCO2) [420 (ambient), 650 (moderate) and 1050 (high) µatm PCO2] over a one-month period." During this time they say they "examined cardiorespiratory physiology, including heart rate, stroke volume, cardiac output and ventilation rate, whole organism metabolism via oxygen consumption rate and sub-organismal aerobic capacity by citrate synthase enzyme activity." And what did they thereby learn?

The four US researchers report that "juvenile fish showed an increase in ventilation rate under high PCO2 compared with ambient CO2, whereas cardiac performance, oxygen consumption and citrate synthase activity were not significantly affected by elevated PCO2." In addition, they state that acclimation time had a significant effect on ventilation rate, stroke volume, cardiac output and citrate synthase activity, such that "all metrics increased over the 4-week exposure period." And in light of these findings, Davis et al. conclude that "juvenile emerald rockcod are robust to near-future increases in ocean acidification and may have the capacity to adjust for future increases in PCO2 by increasing acid-base compensation through increased ventilation."

Posted 26 September 2016