Can variable pH and low oxygen moderate ocean acidification outcomes for mussel larvae?

• Published in: Global Change Biology
• Main Authors: Frieder, Christina A., Gonzalez, Jennifer P., Bockmon, Emily E., Navarro, Michael O., Levin, Lisa A.
• Format: Article in Journal/Newspaper
• Language: English
• Published: Wiley 2014
• Subjects: Ocean acidification
• Online Access: http://dx.doi.org/10.1111/gcb.12485; https://api.wiley.com/onlinelibrary/tdm/v1/articles/10.1111%2Fgcb.12485; https://onlinelibrary.wiley.com/doi/pdf/10.1111/gcb.12485

Abstract Natural variation and changing climate in coastal oceans subject meroplanktonic organisms to broad ranges of pH and oxygen ([O 2 ]) levels. In controlled‐laboratory experiments we explored the interactive effects of pH , [O 2 ], and semidiurnal pH fluctuations on the survivorship, development, and size of early life stages of two mytilid mussels, Mytilus californianus and M. galloprovincialis . Survivorship of larvae was unaffected by low pH , low [O 2 ], or semidiurnal fluctuations for both mytilid species. Low pH (<7.6) resulted in delayed transition from the trochophore to veliger stage, but this effect of low pH was absent when incorporating semidiurnal fluctuations in both species. Also at low pH , larval shells were smaller and had greater variance; this effect was absent when semidiurnal fluctuations of 0.3 units were incorporated at low pH for M. galloprovincialis but not for M. californianus . Low [O 2 ] in combination with low pH had no effect on larval development and size, indicating that early life stages of mytilid mussels are largely tolerant to a broad range of [O 2 ] reflective of their environment (80–260 μ mol kg −1 ). The role of pH variability should be recognized as an important feature in coastal oceans that has the capacity to modulate the effects of ocean acidification on biological responses.