Effect of ocean acidification on the benthic foraminifera Ammonia sp. is caused by a decrease in carbonate ion concentration

About 30% of the anthropogenically released CO 2 is taken up by the oceans; such uptake causes surface ocean pH to decrease and is commonly referred to as ocean acidification (OA). Foraminifera are one of the most abundant groups of marine calcifiers, estimated to precipitate ca. 50 % of biogenic ca...

Full description

Bibliographic Details
Published in:Biogeosciences
Main Authors: N. Keul, G. Langer, L. J. de Nooijer, J. Bijma
Format: Article in Journal/Newspaper
Language:English
Published: Copernicus Publications 2013
Subjects:
Online Access:https://doi.org/10.5194/bg-10-6185-2013
https://doaj.org/article/6fbb7afcccc0482583c621a1c688dd11
Description
Summary:About 30% of the anthropogenically released CO 2 is taken up by the oceans; such uptake causes surface ocean pH to decrease and is commonly referred to as ocean acidification (OA). Foraminifera are one of the most abundant groups of marine calcifiers, estimated to precipitate ca. 50 % of biogenic calcium carbonate in the open oceans. We have compiled the state of the art literature on OA effects on foraminifera, because the majority of OA research on this group was published within the last three years. Disparate responses of this important group of marine calcifiers to OA were reported, highlighting the importance of a process-based understanding of OA effects on foraminifera. We cultured the benthic foraminifer Ammonia sp. under a range of carbonate chemistry manipulation treatments to identify the parameter of the carbonate system causing the observed effects. This parameter identification is the first step towards a process-based understanding. We argue that [CO 3 2− ] is the parameter affecting foraminiferal size-normalized weights (SNWs) and growth rates. Based on the presented data, we can confirm the strong potential of Ammonia sp. foraminiferal SNW as a [CO 3 2− ] proxy.