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Titolo:
Mg/Ca ratios in stressed foraminifera, Amphistegina gibbosa, from the Florida Keys
Autore:
Toler, SK; Hallock, P; Schijf, J;
Indirizzi:
Univ S Florida, Coll Marine Sci, St Petersburg, FL 33701 USA Univ S Florida St Petersburg FL USA 33701 ci, St Petersburg, FL 33701 USA
Titolo Testata:
MARINE MICROPALEONTOLOGY
fascicolo: 3-4, volume: 43, anno: 2001,
pagine: 199 - 206
SICI:
0377-8398(200111)43:3-4<199:MRISFA>2.0.ZU;2-L
Fonte:
ISI
Lingua:
ENG
Soggetto:
BENTHIC FORAMINIFERA; ORGANIC MATRIX; POLLUTION; CALCITE; TESTS;
Keywords:
foraminifera; Inductively-Coupled Plasma Mass Spectrometer (ICP-MS); magnesium; calcium;
Tipo documento:
Article
Natura:
Periodico
Settore Disciplinare:
Physical, Chemical & Earth Sciences
Citazioni:
31
Recensione:
Indirizzi per estratti:
Indirizzo: Toler, SK Univ S Florida, Coll Marine Sci, 140 7th Ave S, St Petersburg, FL 33701 USA Univ S Florida 140 7th Ave S St Petersburg FL USA 33701 3701 USA
Citazione:
S.K. Toler et al., "Mg/Ca ratios in stressed foraminifera, Amphistegina gibbosa, from the Florida Keys", MAR MICROPA, 43(3-4), 2001, pp. 199-206

Abstract

Since 1991, significant proportions of Amphistegina populations in the Florida Keys and elsewhere have exhibited stress symptoms that include loss ofsymbiont color ('bleaching'), anomalous shell breakage and reproductive damage. Previous studies of other taxa have reported elevated Mg/Ca ratios intests from pollution-stressed foraminiferal populations. The purpose of this study was to test the hypothesis that anomalous shell breakage in stressed Amphistegina gibbosa is the result of loss of control of calcification, resulting in elevated concentrations of Mg that weaken the crystal structure of the test. Analysis of Mg and Ca concentrations in A. gibbosa tests, using an Inductively-Coupled Plasma Mass Spectrometer, revealed normal Mg/Ca (2-5 mol%) in all specimens analyzed, including normal specimens collected in 1982 (priorto the onset of the stress event), and both normal and broken specimens collected quarterly from afflicted populations in 1996. Analysis of specimensfrom the high Mg calcite taxon, Archaias angulatus, revealed Mg/Ca of 10-14 mol%. This study, which presents an ICP-MS procedure that can be used to assess Mg/Ca in individual foraminifera, does not support the hypothesis that shell breakage in stressed Amphistegina results from disruption of calcification at the ionic level. (C) 2001 Elsevier Science B.V. All rights reserved.

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Documento generato il 26/09/20 alle ore 05:25:22