Marine Science Faculty Publications
Document Type
Article
Publication Date
2017
Keywords
dissolved organic matter, Gulf of Mexico, radiocarbon, dissolved organic carbon, 13C, oil spill
Digital Object Identifier (DOI)
https://doi.org/10.1002/2017GL074155
Abstract
Dissolved organic carbon (DOC) is of primary importance to marine ecosystems and the global carbon cycle. Stable carbon (δ13C) and radiocarbon (Δ14C) isotopic measurements are powerful tools for evaluating DOC sources and cycling. However, the isotopic signature of DOC in the Gulf of Mexico (GOM) remains almost completely unknown. Here we present the first DOC Δ14C and δ13C depth profiles from the GOM. Our results suggest the Mississippi River exports large amounts of DOC with an anthropogenic “bomb” Δ14C signature. Riverine DOC is removed and recycled offshore, and some marine production of DOC is observed in the river plume. Offshore profiles show that DOC has higher Δ14C than its Caribbean feed waters, indicative of a modern deep DOC source in the GOM basin. Finally, high DOC with negative δ13C and Δ14C values were observed near the Macondo Wellhead, suggesting a transformation of Deepwater Horizon hydrocarbons into a persistent population of DOC.
Rights Information
Was this content written or created while at USF?
Yes
Citation / Publisher Attribution
Geophysical Research Letters, v. 44, issue 16, p. 8424-8434
©2017. American Geophysical Union. All Rights Reserved.
Scholar Commons Citation
Walker, B. D.; Druffel, E. R. M.; Kolasinski, J.; Roberts, B. J.; Xu, X.; and Rosenheim, B. E., "Stable and Radiocarbon Isotopic Composition of Dissolved Organic Matter in the Gulf of Mexico" (2017). Marine Science Faculty Publications. 2429.
https://digitalcommons.usf.edu/msc_facpub/2429
Supporting Information S1
