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The Non-Impacts of Ocean Acidification on the Early Life Stages of Northern Rock Sole

Paper Reviewed
Hurst, T.P., Laurel, B.J., Hanneman, E., Haines, S.A. and Ottmar, M.L.. 2017. Elevated CO2 does not exacerbate nutritional stress in larvae of a Pacific flatfish. Fisheries Oceanography 26: 336-349.

In contemporary fisheries science, researchers have long been exploring how naturally-varying environmental factors influence fish growth and survival, particularly in commercially important species. Only recently, however, have they begun to explore how these natural factors might interact with future predictions of climate change, including changes from the much-hyped future projections of ocean acidification. However, according to Hurst et al. (2017), despite all of the research that has been conducted to date, they say "there have been no published studies examining the interactive effects of CO2 level and nutritional [condition] in a marine fish."

In an attempt to remedy this data discrepancy, Hurst et al. set out to examine the combined effects of nutritional condition/feeding status and ocean acidification (elevated seawater pCO2) on the early life stages of northern rock sole (Lepidopsetta polyxystra), a commercially important flatfish in the North Pacific Ocean. To do so, they reared larvae in one of three feeding treatments (low, medium and high) and two CO2 treatments (pH of 7.6 for low and pH of 8.0 for normal, or ambient, seawater) over a period of one to three months (to cover both the pre-flexion and post-flexion larval stages).

Results of the analysis, in the words of the authors, revealed that "in both stages, the larval feeding regime has a much larger impact on growth rates than did the CO2 level, and there was no observed interaction between stressors." As a result of this and other (non) findings, Hurst et al. conclude that "the effects of elevated CO2 levels are relatively modest in this species (compared to other aspects of the rearing environment)." And thus we find yet another example of a marine species that appears to be unaffected by future projections of ocean acidification. For more examples, read the many reviews we have posted on other papers here.

Posted 21 September 2017