Porites Calcifying Fluid pH on Seasonal to Diurnal Scales - Archive ouverte HAL
Article Dans Une Revue Journal of Geophysical Research. Oceans Année : 2021

Porites Calcifying Fluid pH on Seasonal to Diurnal Scales

Résumé

Abstract Coral resilience to ocean acidification is largely determined by the degree of physiological control corals can exert on their calcifying fluid carbonate chemistry. In this study, the boron isotopic composition (δ 11 B) of a Porites colony growing on a reef flat on Kiritimati Island in the equatorial central Pacific is examined to quantify the sensitivity of calcifying fluid pH (pH cf ) to ambient environmental conditions. Skeletal δ 11 B along the growth axis of one annual growth band was determined with bulk analysis and by laser ablation (LA) MC‐ICP‐MS. Furthermore, the oxygen and carbon isotopic composition, trace element ratios, and skeletal density were quantified. Sclerochronological data were interpreted in the context of simultaneous recordings of reef flat seawater pH (pH sw ), temperature, salinity, and water depth, and by measurements of these parameters on the fore‐reef. A recent model of pH cf upregulation, after optimization with seasonally resolved data, was used to simulate pH cf variability on a diurnal scale. Results showed that on a seasonal scale, Porites pH cf is upregulated compared to ambient seawater: both bulk and LA‐MC‐ICP‐MS derived δ 11 B resulted in a mean pH cf of 8.35 pH units. Calcifying fluid pH upregulation primarily followed variations in seawater temperatures, that is likely related to the control of temperature on calcification rate. On the reef flat, the diurnal range in pH sw was substantially higher (0.29 pH units) than on the fore‐reef (0.07 pH units). However, model results suggest that the high diurnal variability in reef flat pH sw resulted only in a limited variability in Porites pH cf .
Fichier principal
Vignette du fichier
JGR Oceans - 2021 - Knebel - Porites Calcifying Fluid pH on Seasonal to Diurnal Scales.pdf (1.33 Mo) Télécharger le fichier
Origine Fichiers éditeurs autorisés sur une archive ouverte

Dates et versions

hal-04707857 , version 1 (25-09-2024)

Identifiants

Citer

Oliver Knebel, Carlos Carvajal, Christopher Standish, Elwyn de La Vega, Thomas B. Chalk, et al.. Porites Calcifying Fluid pH on Seasonal to Diurnal Scales. Journal of Geophysical Research. Oceans, 2021, 126 (3), ⟨10.1029/2020JC016889⟩. ⟨hal-04707857⟩
56 Consultations
7 Téléchargements

Altmetric

Partager

More