The effects of ocean acidification and increased temperatures on the survival, growth, and morphology of red king crab (Paralithodes camtschaticus) (NCEI Accession 0170753)

Multiple stressor studies are needed to better understand the effects of oceanic changes on marine organisms. To determine the effects of near-future ocean acidification and warming temperature on young of the year red king crab (Paralithodes camtschaticus) survival, growth, and morphology, we conducted a long-term (184 d) fully crossed experiment with two pHs and three temperatures: ambient pH (~7.99), pH 7.8, ambient temperature, ambient +2 degrees Celsius, and ambient +4 degrees Celsius, for a total of 6 treatments. Mortality rate increased with both reduced pH and by higher temperatures, but interpretation of the ultistressor effects is not straightforward as a clear trend was not observed. A synergetic effect was observed; the pH 7.8 and ambient +4 degrees Celsius temperature treatment had the lowest survival, with only 3% surviving to the end of the experiment. However, antagonistic effects were observed in the pH 7.8 ambient +2 degrees Celsius temperature treatment; the mortality rate in this treatment was less than the mortality rate of each of the stressors individually. Despite the effects on mortality, neither decreased pH nor increased temperature had an effect on growth or morphology. The results of this study combined with other studies suggest that ocean acidification and warming may have profound negative effects on red king crab populations in the upcoming decades unless the species is able to quickly adapt or acclimate to changing conditions.