Spatial linkages between coral proxies of terrestrial runoff across a large embayment in Madagascar

C. A. Grove, J. Zinke, T. Scheufen, J. Maina, E. Epping, W. Boer, B. Randriamanantsoa, G. J A Brummer

Research output: Contribution to journalArticleResearchpeer-review

Abstract

Coral cores provide vital climate reconstructions for site-specific temporal variability in river flow and sediment load. Yet, their ability to record spatial differences across multiple catchments is relatively unknown. Here, we investigate spatial linkages between four coral proxies of terrestrial runoff and their relationships between sites. Coral cores were drilled in and around Antongil Bay, the largest bay in Madagascar, and individually analysed for fifteen years of continuous luminescence (G / B), Ba / Ca, δ18Osw and δ13C data. Each coral core was drilled close to individual river mouths (≤7 km), and proxy data were compared to modelled river discharge and sediment runoff data for the three corresponding catchments. A reasonable agreement between terrestrial runoff proxies with modelled river discharge and sediment yield was observed. Some inconsistencies between proxy and modelled data are likely linked to proxy behaviour, watershed size and local environmental physiochemical parameters. In general, the further a coral resided from its river source, the weaker the proxy relationship was with modelled data and other corals, due to mixing gradients and currents. Nevertheless, we demonstrate that two coral Ba / Ca and luminescence (G / B) records influenced by the same watershed are reproducible. Furthermore, a strong Ba / Ca relationship was observed between two cores from distant watersheds, with baseline averages in agreement with modelled sediment runoff data. As humic acids behave conservatively in the water column, luminescence (G / B) data gave the highest regional correlations between cores, and showed the most consistent relationship with site specific modelled discharge. No statistical relationship was observed between cores in terms of interannual δ18Osw and δ13C, meaning corals were recording a localised signal at their respective sites, confounded by vital effects. Comparing proxy baseline averages and mean seasonal cycles provided a good overview of the runoff dynamics of the bay system.

LanguageEnglish
Pages3063-3081
Number of pages19
JournalBiogeosciences
Volume9
Issue number8
DOIs
Publication statusPublished - 2012

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Madagascar
corals
coral
runoff
luminescence
rivers
fluvial deposit
watershed
river discharge
sediments
catchment
sediment yield
humic acids
river flow
river
humic acid
mouth
water column
climate
sediment

Bibliographical note

Copyright the Author(s) [2012]. Originally published in Biogeosciences, 9, 3063-3081, doi:10.5194/bg-9-3063-2012, 2012. Version archived for private and non-commercial use with the permission of the author/s and according to publisher conditions. For further rights please contact the publisher.

Cite this

Grove, C. A., Zinke, J., Scheufen, T., Maina, J., Epping, E., Boer, W., ... Brummer, G. J. A. (2012). Spatial linkages between coral proxies of terrestrial runoff across a large embayment in Madagascar. Biogeosciences, 9(8), 3063-3081. https://doi.org/10.5194/bg-9-3063-2012
Grove, C. A. ; Zinke, J. ; Scheufen, T. ; Maina, J. ; Epping, E. ; Boer, W. ; Randriamanantsoa, B. ; Brummer, G. J A. / Spatial linkages between coral proxies of terrestrial runoff across a large embayment in Madagascar. In: Biogeosciences. 2012 ; Vol. 9, No. 8. pp. 3063-3081.
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Grove, CA, Zinke, J, Scheufen, T, Maina, J, Epping, E, Boer, W, Randriamanantsoa, B & Brummer, GJA 2012, 'Spatial linkages between coral proxies of terrestrial runoff across a large embayment in Madagascar', Biogeosciences, vol. 9, no. 8, pp. 3063-3081. https://doi.org/10.5194/bg-9-3063-2012

Spatial linkages between coral proxies of terrestrial runoff across a large embayment in Madagascar. / Grove, C. A.; Zinke, J.; Scheufen, T.; Maina, J.; Epping, E.; Boer, W.; Randriamanantsoa, B.; Brummer, G. J A.

In: Biogeosciences, Vol. 9, No. 8, 2012, p. 3063-3081.

Research output: Contribution to journalArticleResearchpeer-review

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T1 - Spatial linkages between coral proxies of terrestrial runoff across a large embayment in Madagascar

AU - Grove, C. A.

AU - Zinke, J.

AU - Scheufen, T.

AU - Maina, J.

AU - Epping, E.

AU - Boer, W.

AU - Randriamanantsoa, B.

AU - Brummer, G. J A

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