TY - JOUR
T1 - Isotopic composition of carbonate-bound organic nitrogen in deep-sea scleractinian corals
T2 - A new window into past biogeochemical change
AU - Wang, Xingchen T.
AU - Prokopenko, Maria G.
AU - Sigman, Daniel Mikhail
AU - Adkins, Jess F.
AU - Robinson, Laura F.
AU - Ren, Haojia
AU - Oleynik, Sergey
AU - Williams, Branwen
AU - Haug, Gerald H.
PY - 2014/8/15
Y1 - 2014/8/15
N2 - Over the last two decades, the skeletal remains of deep-sea corals have arisen as a geochemical archive of Pleistocene oceanographic change. Here we report the exploration of the isotopic composition of the carbonate-bound organic nitrogen (hereafter, CB-δ15N) in the deep-sea scleractinian coral Desmophyllum dianthus as a possible tool for reconstructing past changes in the ocean nitrogen cycle. The measurement protocol is adapted from a high-sensitivity method for foraminifera shell-bound δ15N. We explored the variability of CB-δ15N within specimens, among corals collected at different depths in a given ocean region, and among different ocean regions. Modern D. dianthus CB-δ15N is strongly correlated with the δ15N of N export as estimated from sediment traps, shallow subsurface nitrate, and surface sediments, suggesting that CB-δ15N is a reliable proxy for δ15N of N export. D. dianthus CB-δ15N is consistently 8-9‰ higher than δ15N of N export, indicating that D. dianthus acquires its nutrition primarily from suspended particulate organic matter (POM) that derives from sinking POM, not directly from sinking POM.
AB - Over the last two decades, the skeletal remains of deep-sea corals have arisen as a geochemical archive of Pleistocene oceanographic change. Here we report the exploration of the isotopic composition of the carbonate-bound organic nitrogen (hereafter, CB-δ15N) in the deep-sea scleractinian coral Desmophyllum dianthus as a possible tool for reconstructing past changes in the ocean nitrogen cycle. The measurement protocol is adapted from a high-sensitivity method for foraminifera shell-bound δ15N. We explored the variability of CB-δ15N within specimens, among corals collected at different depths in a given ocean region, and among different ocean regions. Modern D. dianthus CB-δ15N is strongly correlated with the δ15N of N export as estimated from sediment traps, shallow subsurface nitrate, and surface sediments, suggesting that CB-δ15N is a reliable proxy for δ15N of N export. D. dianthus CB-δ15N is consistently 8-9‰ higher than δ15N of N export, indicating that D. dianthus acquires its nutrition primarily from suspended particulate organic matter (POM) that derives from sinking POM, not directly from sinking POM.
KW - Deep-sea scleractinian corals
KW - Nitrogen isotopes
KW - Ocean nitrogen cycle
KW - Paleoceanography
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U2 - 10.1016/j.epsl.2014.05.048
DO - 10.1016/j.epsl.2014.05.048
M3 - Article
AN - SCOPUS:84902256894
VL - 400
SP - 243
EP - 250
JO - Earth and Planetary Science Letters
JF - Earth and Planetary Science Letters
SN - 0012-821X
ER -