Description and quantification of pteropod shell dissolution: a sensitive bioindicator of ocean acidification

• Published in: Global change biology Vol. 18; no. 7; pp. 2378 - 2388
• Main Authors: Bednaršek, Nina, Tarling, Geraint A, Bakker, Dorothee CE, Fielding, Sophie, Cohen, Anne, Kuzirian, Alan, McCorkle, Dan, Lézé, Bertrand, Montagna, Roberto
• Format: Journal Article
• Language: English
• Published: Oxford Blackwell Publishing Ltd 01.07.2012; Wiley-Blackwell
• Subjects: Acidity; Animal and plant ecology; Animal populations; Animal, plant and microbial ecology; aragonite shell; bioindicator; Biological and medical sciences; Chemical oceanography; Dissolution; dissolution quantification; Fundamental and applied biological sciences. Psychology; General aspects; Mollusks; ocean acidification; pteropods; shell dissolution; Shells; ocean acidification; Description; Acidification; Biological indicator; pteropods; Dissolution; Aragonite; bioindicator; Shell(anatomy); Ocean; aragonite shell; dissolution quantification; shell dissolution
• ISSN: 1354-1013; 1365-2486
• DOI: 10.1111/j.1365-2486.2012.02668.x

Anthropogenic ocean acidification is likely to have negative effects on marine calcifying organisms, such as shelled pteropods, by promoting dissolution of aragonite shells. Study of shell dissolution requires an accurate and sensitive method for assessing shell damage. Shell dissolution was induced through incubations in CO2‐enriched seawater for 4 and 14 days. We describe a procedure that allows the level of dissolution to be assessed and classified into three main types: Type I with partial dissolution of the prismatic layer; Type II with exposure of underlying crossed‐lamellar layer, and Type III, where crossed‐lamellar layer shows signs of dissolution. Levels of dissolution showed a good correspondence to the incubation conditions, with the most severe damage found in specimens held for 14 days in undersaturated condition (Ω ~ 0.8). This methodology enables the response of small pelagic calcifiers to acidified conditions to be detected at an early stage, thus making pteropods a valuable bioindicator of future ocean acidification.