Response of the Miliolid Archaias angulatus to Simulated Ocean Acidification

Authors

Paul O. Knorr, U.S. Geological Survey
Lisa L. Robbins, U.S. Geological Survey
Peter J. Harries, University of South Florida
Pamela Hallock, University of South FloridaFollow
Jonathan G. Wynn, University of South FloridaFollow

Document Type

Article

Publication Date

2015

Digital Object Identifier (DOI)

https://doi.org/10.2113/gsjfr.45.2.109

Abstract

A common, but not universal, effect of ocean acidification on benthic foraminifera is a reduction in the growth rate. The miliolid Archaias angulatus is a high-Mg (>4 mole% MgCO₃), symbiont-bearing, soritid benthic foraminifer that contributes to Caribbean reef carbonate sediments. A laboratory culture study assessed the effects of reduced pH on the growth of A. angulatus. We observed a statistically significant 50% reduction in the growth rate (p < 0.01), calculated from changes in maximum diameter, from 160 μm/ 28 days in the pH 8.0/pCO_2air 480 ppm control group to 80 μm/28 days at a treatment level of pH 7.6/pCO_2air 1328 ppm. Additionally, pseudopore area, δ¹⁸O values, and Mg/Ca ratio all increased, albeit slightly in the latter two variables. The reduction in growth rate indicates that under a high-CO₂ setting, future A. angulatus populations will consist of smaller adults. A model using the results of this study estimates that at pH 7.6 A. angulatus carbonate production in the South Florida reef tract and Florida Bay decreases by 85%, from 0.27 Mt/yr to 0.04 Mt/yr, over an area of 9,000 km².

Was this content written or created while at USF?

Yes

Citation / Publisher Attribution

Journal of Foraminiferal Research, v. 45, issue 2, p. 109-127

Scholar Commons Citation

Knorr, Paul O.; Robbins, Lisa L.; Harries, Peter J.; Hallock, Pamela; and Wynn, Jonathan G., "Response of the Miliolid Archaias angulatus to Simulated Ocean Acidification" (2015). Marine Science Faculty Publications. 910.
https://digitalcommons.usf.edu/msc_facpub/910