TY - JOUR

T1 - A novel paleo-bleaching proxy using boron isotopes and high-resolution laser ablation to reconstruct coral bleaching events

AU - Dishon, G.

AU - Fisch, J.

AU - Horn, I.

AU - Kaczmarek, K.

AU - Bijma, J.

AU - Gruber, D. F.

AU - Nir, O.

AU - Popovich, Y.

AU - Tchernov, D.

N1 - Acknowledgements: The experimental work for this paper was conducted as part of J. Fisch’s thesis while at Hebrew University in Jerusalem, Israel. The authors would like to acknowledge KlausUwe Richter for all of his analytical support. D. Tchernov and J. Bijma would like to acknowledge financial support from BMBF provided for the project “Reconstruction of past bleaching events using a high resolution microanalysis of δ11B” in the framework of the German Israeli collaboration (03V0956). D. F. Gruber would like to acknowledge funding from the National Science Foundation grant #0920572. G. Dishon would like to acknowledge funding from SBM and Minerva foundation. The authors would also like to acknowledge the Israel National Monitoring Program for the long-term pH and sea surface temperature data in the Gulf of Aqaba. We thank the two anonymous referees who helped improve this manuscript.

PY - 2015/10/8

Y1 - 2015/10/8

N2 - Coral reefs occupy only ∼ 0.1 percent of the ocean's habitat, but are the most biologically diverse marine ecosystem. In recent decades, coral reefs have experienced a significant global decline due to a variety of causes, one of the major causes being widespread coral bleaching events. During bleaching, the coral expels its symbiotic algae, thereby losing its main source of nutrition generally obtained through photosynthesis. While recent coral bleaching events have been extensively investigated, there is no scientific data on historical coral bleaching prior to 1979. In this study, we employ high-resolution femtosecond Laser Ablation Multiple Collector Inductively Coupled Plasma Mass Spectrometry (LA-MC-ICP-MS) to demonstrate a distinct biologically induced decline of boron (B) isotopic composition (δ11B) as a result of coral bleaching. These findings and methodology offer a new use for a previously developed isotopic proxy to reconstruct paleo-coral bleaching events. Based on a literature review of published δ11B data and our recorded vital effect of coral bleaching on the δ11B signal, we also describe at least two possible coral bleaching events since the Last Glacial Maximum. The implementation of this bleaching proxy holds the potential of identifying occurrences of coral bleaching throughout the geological record. A deeper temporal view of coral bleaching will enable scientists to determine if it occurred in the past during times of environmental change and what outcome it may have had on coral population structure. Understanding the frequency of bleaching events is also critical for determining the relationship between natural and anthropogenic causes of these events.

AB - Coral reefs occupy only ∼ 0.1 percent of the ocean's habitat, but are the most biologically diverse marine ecosystem. In recent decades, coral reefs have experienced a significant global decline due to a variety of causes, one of the major causes being widespread coral bleaching events. During bleaching, the coral expels its symbiotic algae, thereby losing its main source of nutrition generally obtained through photosynthesis. While recent coral bleaching events have been extensively investigated, there is no scientific data on historical coral bleaching prior to 1979. In this study, we employ high-resolution femtosecond Laser Ablation Multiple Collector Inductively Coupled Plasma Mass Spectrometry (LA-MC-ICP-MS) to demonstrate a distinct biologically induced decline of boron (B) isotopic composition (δ11B) as a result of coral bleaching. These findings and methodology offer a new use for a previously developed isotopic proxy to reconstruct paleo-coral bleaching events. Based on a literature review of published δ11B data and our recorded vital effect of coral bleaching on the δ11B signal, we also describe at least two possible coral bleaching events since the Last Glacial Maximum. The implementation of this bleaching proxy holds the potential of identifying occurrences of coral bleaching throughout the geological record. A deeper temporal view of coral bleaching will enable scientists to determine if it occurred in the past during times of environmental change and what outcome it may have had on coral population structure. Understanding the frequency of bleaching events is also critical for determining the relationship between natural and anthropogenic causes of these events.

UR - http://www.scopus.com/inward/record.url?scp=84943737926&partnerID=8YFLogxK

U2 - 10.5194/bg-12-5677-2015

DO - 10.5194/bg-12-5677-2015

M3 - Article

AN - SCOPUS:84943737926

VL - 12

SP - 5677

EP - 5687

JO - BIOGEOSCIENCES

JF - BIOGEOSCIENCES

SN - 1726-4170

IS - 19

ER -