While ocean acidification is likely to have major effects on many marine organisms, those species that regularly experience variable pCO2 environments may be more tolerant of future predicted changes in ocean chemistry. Euphausia pacifica is an abundant krill species along the Pacific coast of North America and one that regularly experiences varying pCO2 levels during seasonal upwelling, as well as during daily vertical migrations to depth where pCO2 is higher.
Increasing atmospheric CO2 concentrations are causing ocean acidification (OA), altering carbonate chemistry with consequences for marine organisms. Here we show that OA increases by 46–212% the production of phenolic compounds in phytoplankton grown under the elevated CO2 concentrations projected for the end of this century, compared with the ambient CO2 level. At the same time, mitochondrial respiration rate is enhanced under elevated CO2 concentrations by 130–160% in a single species or mixed phytoplankton assemblage.