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The Resilience of Juvenile Rockfish to Ocean Acidification and Hypoxia

Paper Reviewed
Davis, B.E., Komoroske, L.M., Hansen, M.J., Poletto, J.B., Perry, E.N., Miller, N.A., Ehlman, S.M., Wheeler, S.G., Sih, A., Todgham, A.E. and Fangue, N.A. 2018. Juvenile rockfish show resilience to CO2-acidification and hypoxia across multiple biological scales. Conservation Physiology 6: coy038; doi:10.1093/conphys/coy038.

Davis et al. (2018) investigated the impact of ocean acidification and hypoxia on the predator-prey relationship of two co-occurring fish species, juvenile rockfish (Sebastes, the genus level) and cabezon (Scorpaenichthys marmoratus).

The fish were collected from seagrass beds in Campbell Cove, CA, USA, and immediately transported to the Bodega Marine Laboratory at the University of California, Davis, where they were acclimated for 4-6 weeks prior to the start of their experiment. Thereafter, they were exposed to one of two pCO2 levels (~600 µatm for ambient or ~1600 µatm for high) and one of two dissolved oxygen (DO) levels (8.0 mg per liter for normoxic or 4.5 mg per liter for hypoxic), following which the researchers conducted assessments of the fishes' cellular metabolism, prey behavior and predation mortality rates after 1 and 3 weeks of treatment exposure.

According to Davis et al., the results of their study revealed that "juvenile rockfish had the capacity to acclimate to elevated pCO2 and low DO, such that short-term alterations in physiology and behavior were restored after 3 weeks of acclimation, which correlated with decreased predation mortality." Such positive findings, they write, likely resulted from "adaptive strategies" that rockfish have developed to cope with broad ranges of pCO2 and DO levels that are experienced in their natural seagrass bed environment. Consequently, the team of three researchers conclude that their data suggest that rockfish "may be resilient to changes in environmental stressors predicted by climate models."

Posted 1 November 2018