Ocean acidification bends the Mermaid’s Wineglass

<jats:p> Ocean acidification lowers the saturation state of calcium carbonate, decreasing net calcification and compromising the skeletons of organisms such as corals, molluscs and algae. These calcified structures can protect organisms from predation and improve access to light, nutrients and...

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Bibliographic Details
Published in:Biology Letters
Main Authors: Newcomb, LA, Milazzo, M, Hall-Spencer, JM, Carrington, E
Format: Article in Journal/Newspaper
Language:English
Published: The Royal Society 2015
Subjects:
Online Access:http://hdl.handle.net/10026.1/3795
https://doi.org/10.1098/rsbl.2014.1075
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Summary:<jats:p> Ocean acidification lowers the saturation state of calcium carbonate, decreasing net calcification and compromising the skeletons of organisms such as corals, molluscs and algae. These calcified structures can protect organisms from predation and improve access to light, nutrients and dispersive currents. While some species (such as urchins, corals and mussels) survive with decreased calcification, they can suffer from inferior mechanical performance. Here, we used cantilever beam theory to test the hypothesis that decreased calcification would impair the mechanical performance of the green alga <jats:italic>Acetabularia acetabulum</jats:italic> along a CO <jats:sub>2</jats:sub> gradient created by volcanic seeps off Vulcano, Italy. Calcification and mechanical properties declined as calcium carbonate saturation fell; algae at 2283 µatm CO <jats:sub>2</jats:sub> were 32% less calcified, 40% less stiff and 40% droopier. Moreover, calcification was not a linear proxy for mechanical performance; stem stiffness decreased exponentially with reduced calcification. Although calcifying organisms can tolerate high CO <jats:sub>2</jats:sub> conditions, even subtle changes in calcification can cause dramatic changes in skeletal performance, which may in turn affect key biotic and abiotic interactions. </jats:p>