کد مقاله | کد نشریه | سال انتشار | مقاله انگلیسی | نسخه تمام متن |
---|---|---|---|---|
6428785 | 1634756 | 2014 | 8 صفحه PDF | دانلود رایگان |
- Nitrogen isotopes of carbonate-bound organics in deep-sea Scleractinia are measured.
- D. dianthus CB-δ15N is correlated with the δ15N of N export from the surface ocean.
- D. dianthus acquires its nutrition primarily from suspended POM.
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 8-9Ⱐhigher 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.
Journal: Earth and Planetary Science Letters - Volume 400, 15 August 2014, Pages 243-250