NDLI: Sediment-water fluxes of dissolved inorganic carbon, O2, nutrients, and N2 from the hypoxic region of the Louisiana continental shelf

Content Provider	Springer Nature Link
Author	Lehrter, John C. Beddick, David L. Devereux, Richard Yates, Diane F. Murrell, Michael C.
Copyright Year	2011
Abstract	Globally, hypoxic areas (<63 mmol O2 m−3) in coastal waters are increasing in number and spatial extent. One of the largest coastal hypoxic regions has been observed during the summer in the bottom-water of the Louisiana continental shelf. The shelf receives the sediments, organic matter, and nutrients exported from the Mississippi River watershed, and much of this material is ultimately deposited to the sea floor. Hence, quantifying the rates of sediment-water dissolved inorganic carbon (DIC), oxygen (O2), and nutrient fluxes is important for understanding how these processes relate to the development and maintenance of hypoxia. In this study, the sediment-water fluxes of DIC, O2, nutrients, and N2 (denitrification) were measured on the Louisiana shelf during six cruises from 2005 to 2007. On each cruise, three to four sites were occupied in or directly adjacent to the region of the shelf that experiences hypoxia. DIC fluxes, a proxy for total sediment respiration, ranged from 7.9 to 21.4 mmol m−2 day−1 but did not vary significantly either spatially or as a function of bottom-water O2 concentration. Overall, sediment respiration and nutrient flux rates were small in comparison to water-column respiration and phytoplankton nutrient demand. Nitrate fluxes were correlated with bottom-water O2 concentrations (r = 0.69), and there was evidence that decreasing O2 concentrations inhibited coupled nitrification-denitrification. Denitrification rates averaged 1.4 mmol N m−2 day−1. Scaled to the area of the shelf, the denitrification sink represented approximately 39% of the N load from the Mississippi River watershed. The sediment-water fluxes reported from this study add substantial information on the spatial and temporal patterns in carbon, O2, and nutrient cycling available for the Louisiana continental shelf and, thus, improve the understanding of this system.
Starting Page	233
Ending Page	252
Page Count	20
File Format	PDF
ISSN	01682563
Journal	Biogeochemistry
Volume Number	109
Issue Number	1-3
e-ISSN	1573515X
Language	English
Publisher	Springer Netherlands
Publisher Date	2011-07-29
Publisher Place	Dordrecht
Access Restriction	Subscribed
Subject Keyword	Sediment-water DIC O2 and nutrient flux Denitrification Hypoxia LOUISIANA shelf Life Sciences Environmental Chemistry Ecosystems Biogeosciences
Content Type	Text
Resource Type	Article
Subject	Earth-Surface Processes Environmental Chemistry Water Science and Technology

Sl.	Authority	Responsibilities	Communication Details
1	Ministry of Education (GoI), Department of Higher Education	Sanctioning Authority	https://www.education.gov.in/ict-initiatives
2	Indian Institute of Technology Kharagpur	Host Institute of the Project: The host institute of the project is responsible for providing infrastructure support and hosting the project	https://www.iitkgp.ac.in
3	National Digital Library of India Office, Indian Institute of Technology Kharagpur	The administrative and infrastructural headquarters of the project	Dr. B. Sutradhar bsutra@ndl.gov.in
4	Project PI / Joint PI	Principal Investigator and Joint Principal Investigators of the project	Dr. B. Sutradhar bsutra@ndl.gov.in Prof. Saswat Chakrabarti will be added soon
5	Website/Portal (Helpdesk)	Queries regarding NDLI and its services	support@ndl.gov.in
6	Contents and Copyright Issues	Queries related to content curation and copyright issues	content@ndl.gov.in
7	National Digital Library of India Club (NDLI Club)	Queries related to NDLI Club formation, support, user awareness program, seminar/symposium, collaboration, social media, promotion, and outreach	clubsupport@ndl.gov.in
8	Digital Preservation Centre (DPC)	Assistance with digitizing and archiving copyright-free printed books	dpc@ndl.gov.in
9	IDR Setup or Support	Queries related to establishment and support of Institutional Digital Repository (IDR) and IDR workshops	idr@ndl.gov.in

Net sediment N2 fluxes in a southern New England estuary: variations in space and time

Effects of sunlight on the production of dissolved organic and inorganic nutrients from resuspended sediments

Sources and export fluxes of inorganic and organic carbon and nutrient species from the seasonally ice-covered Yukon River

Effect of nutrient loading on biogeochemical processes in tropical tidal creeks

Denitrification, dissimilatory nitrate reduction to ammonium, and nitrogen fixation along a nitrate concentration gradient in a created freshwater wetland

Seasonal variation in dissolved carbon concentrations and fluxes in the upper Purus River, southwestern Amazon

Southeastern U.S.A. continental shelf respiratory rates revisited

Pelagic community respiration on the continental shelf off Georgia, USA

Enhanced dissolved organic carbon production in aquatic ecosystems in response to elevated atmospheric CO2

Sediment-water fluxes of dissolved inorganic carbon, O2, nutrients, and N2 from the hypoxic region of the Louisiana continental shelf

Similar Documents

Net sediment N2 fluxes in a southern New England estuary: variations in space and time

Effects of sunlight on the production of dissolved organic and inorganic nutrients from resuspended sediments

Sources and export fluxes of inorganic and organic carbon and nutrient species from the seasonally ice-covered Yukon River

Effect of nutrient loading on biogeochemical processes in tropical tidal creeks

Denitrification, dissimilatory nitrate reduction to ammonium, and nitrogen fixation along a nitrate concentration gradient in a created freshwater wetland

Seasonal variation in dissolved carbon concentrations and fluxes in the upper Purus River, southwestern Amazon

Southeastern U.S.A. continental shelf respiratory rates revisited

Pelagic community respiration on the continental shelf off Georgia, USA

Enhanced dissolved organic carbon production in aquatic ecosystems in response to elevated atmospheric CO2

Sediment-water fluxes of dissolved inorganic carbon, O2, nutrients, and N2 from the hypoxic region of the Louisiana continental shelf