Quick
Search: 		  
advanced search
 GSW Home   GeoRef Home   My GSW Alerts   Contact GSW   About GSW   Journals List   Help 
Geology Signup for GSW Email News
JOURNAL HOME HELP CONTACT PUBLISHER SUBSCRIBE ARCHIVE SEARCH TABLE OF CONTENTS
Geology; March 1996; v. 24; no. 3; p. 227-230; DOI: 10.1130/0091-7613(1996)024<0227:SODICS>2.3.CO;2
© 1996 Geological Society of America
This Article
Right arrow Full Text (PDF)
Right arrow Alert me when this article is cited
Right arrow Alert me if a correction is posted
Right arrow Citation Map
Services
Right arrow Email this article to a friend
Right arrow Similar articles in this journal
Right arrow Alert me to new issues of the journal
Right arrow Download to citation manager
Right arrow reprints & permissions
Citing Articles
Right arrow Citing Articles via HighWire
Right arrow Citing Articles via Google Scholar
Google Scholar
Right arrow Articles by Sen Gupta, B. K.
Right arrow Articles by Rabalais, N. N.
Right arrow Search for Related Content
GeoRef
Right arrow GeoRef Citation

Seasonal oxygen depletion in continental-shelf waters of Louisiana: Historical record of benthic foraminifers

Barun K. Sen Gupta1, R. Eugene Turner2 and Nancy N. Rabalais3

1 Department of Geology and Geophysics, Louisiana State University, Baton Rouge, Louisiana 70803
2 Department of Oceanography and Coastal Sciences, and Coastal Ecology Institute, Louisiana State University, Baton Rouge, Louisiana 70803
3 Louisiana Universities Marine Consortium, Chauvin, Louisiana 70344

A strong spring and summer oxygen depletion is induced in nearshore bottom waters of the Louisiana continental shelf by density stratification and by the carbon flux from phytoplankton production, which, in turn, is related to the nutrient load of the Mississippi and Atchafalaya rivers. In an attempt to read the historical record of this shelf hypoxia during the past two centuries, we compared the stratigraphic signals of benthic foraminifera (as reflected in a relative-dominance index for two common species of Ammonia and Elphidium) in 210Pb-dated cores, and we found evidence of an overall rise in oxygen stress (in intensity or duration), especially in the past 100 yr. This implies a progressive increase in the influence of river-borne nutrients, particularly anthropogenically influenced nitrates. Judging by our results, foraminiferal indices based on appropriate species ratios should prove useful in testing hypotheses about long-term environmental stresses, including eutrophication and paleohypoxia, on other marine shelves.




This article has been cited by other articles:


Home page
 Journal of Foraminiferal ResearchHome page
M. Martinez-Colon, P. Hallock, and C. Green-Ruiz
STRATEGIES FOR USING SHALLOW-WATER BENTHIC FORAMINIFERS AS BIOINDICATORS OF POTENTIALLY TOXIC ELEMENTS: A REVIEW
Journal of Foraminiferal Research, October 1, 2009; 39(4): 278 - 299.
[Abstract] [Full Text] [PDF]

Home page
 ScienceHome page
R. J. Diaz and R. Rosenberg
Spreading Dead Zones and Consequences for Marine Ecosystems
Science, August 15, 2008; 321(5891): 926 - 929.
[Abstract] [Full Text] [PDF]

Home page
 PALAIOSHome page
M.-V. GUILLEM, P. HALLOCK, and M. BRANDANO
A DEPOSITIONAL MODEL AND PALEOECOLOGICAL RECONSTRUCTION OF THE LOWER TORTONIAN DISTALLY STEEPENED RAMP OF MENORCA (BALEARIC ISLANDS, SPAIN)
Palaios, July 1, 2008; 23(7): 465 - 481.
[Abstract] [Full Text] [PDF]

Home page
 Proc. Natl. Acad. Sci. USAHome page
J. P. Smol
Marine sediments tell it like it was
PNAS, November 6, 2007; 104(45): 17563 - 17564.
[Full Text] [PDF]

Home page
 Journal of Foraminiferal ResearchHome page
C. A. Brunner, J. M. Beall, S. J. Bentley, and Y. Furukawa
HYPOXIA HOTSPOTS IN THE MISSISSIPPI BIGHT
Journal of Foraminiferal Research, April 1, 2006; 36(2): 95 - 107.
[Abstract] [Full Text] [PDF]

Home page
 GeologyHome page
L. E. Osterman, R. Z. Poore, P. W. Swarzenski, and R. E. Turner
Reconstructing a 180 yr record of natural and anthropogenic induced low-oxygen conditions from Louisiana continental shelf sediments
Geology, April 1, 2005; 33(4): 329 - 332.
[Abstract] [Full Text] [PDF]

Home page
 Journal of Foraminiferal ResearchHome page
P. Buzas-Stephens, P. Buzas-Stephens, E. A. Pessagno Jr., and C. J. Bowen
FORAMINIFERAL RESPONSE TO HABITAT DISRUPTION: ARROYO COLORADO, TEXAS
Journal of Foraminiferal Research, October 1, 2003; 33(4): 294 - 308.
[Abstract] [Full Text] [PDF]

Home page
 J. Environ. Qual.Home page
R. J. Diaz
Overview of Hypoxia around the World
J. Environ. Qual., March 1, 2001; 30(2): 275 - 281.
[Abstract] [Full Text] [PDF]

Home page
 J. Environ. Qual.Home page
N. N. Rabalais, R.E. Turner, and W. J. Wiseman Jr.
Hypoxia in the Gulf of Mexico
J. Environ. Qual., March 1, 2001; 30(2): 320 - 329.
[Abstract] [Full Text] [PDF]

Home page
 Journal of Foraminiferal ResearchHome page
R. T. Patterson, R. T. Patterson, J.-P. Guilbault, and R. E. Thomson
OXYGEN LEVEL CONTROL ON FORAMINIFERAL DISTRIBUTION IN EFFINGHAM INLET, VANCOUVER ISLAND, BRITISH COLUMBIA, CANADA
Journal of Foraminiferal Research, October 1, 2000; 30(4): 321 - 335.
[Abstract] [Full Text] [PDF]

Home page
 Proc. Natl. Acad. Sci. USAHome page
R. E. Turner, N. Qureshi, N. N. Rabalais, Q. Dortch, D. Justic, R. F. Shaw, and J. Cope
Fluctuating silicate:nitrate ratios and coastal plankton food webs
PNAS, October 27, 1998; 95(22): 13048 - 13051.
[Abstract] [Full Text] [PDF]


JOURNAL HOME HELP CONTACT PUBLISHER SUBSCRIBE ARCHIVE SEARCH TABLE OF CONTENTS
Copyright © 2009 by Geological Society of America