Historical baselines and the future of shell calcification for a foundation species in a changing ocean

Proceedings of the Royal Society B
By: , and 



Seawater pH and the availability of carbonate ions are decreasing due to anthropogenic carbon dioxide emissions, posing challenges for calcifying marine species. Marine mussels are of particular concern given their role as foundation species worldwide. Here, we document shell growth and calcification patterns in Mytilus californianus, the California mussel, over millennial and decadal scales. By comparing shell thickness across the largest modern shells, the largest mussels collected in the 1960s–1970s and shells from two Native American midden sites (∼1000–2420 years BP), we found that modern shells are thinner overall, thinner per age category and thinner per unit length. Thus, the largest individuals of this species are calcifying less now than in the past. Comparisons of shell thickness in smaller individuals over the past 10–40 years, however, do not show significant shell thinning. Given our sampling strategy, these results are unlikely to simply reflect within-site variability or preservation effects. Review of environmental and biotic drivers known to affect shell calcification suggests declining ocean pH as a likely explanation for the observed shell thinning. Further future decreases in shell thickness could have significant negative impacts on M. californianus survival and, in turn, negatively impact the species-rich complex that occupies mussel beds..

Publication type Article
Publication Subtype Journal Article
Title Historical baselines and the future of shell calcification for a foundation species in a changing ocean
Series title Proceedings of the Royal Society B
DOI 10.1098/rspb.2016.0392
Volume 283
Issue 1832
Year Published 2016
Language English
Publisher The Royal Society
Contributing office(s) Western Ecological Research Center
Description 8 p.
First page 1
Last page 8
Online Only (Y/N) N
Additional Online Files (Y/N) N
Google Analytic Metrics Metrics page
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