Publications and On-line Reports
The USGS Toxics program maintains
a complete bibliography of publications produced by USGS researchers.
This bibliography can be queried in a variety of ways. Try searching
the toxics program bibliography
using key words such as: hypoxia, hypoxic, Gulf of Mexico, nitrate,
nutrient, or nitrogen.
An
Assessment of Coastal Hypoxia and Eutrophication in U.S. Waters
by Donald Scavia and others.
- This report responds to Congresses call for an “Assessment
of Hypoxia” as described in the Harmful Algal Bloom and Hypoxia
Research and Control Act of 1998 (“HABHRCA,” Title VI
of P.L. 105 383, section 604(b)). The Assessment examines “the
ecological and economic consequences of hypoxia in United States
coastal waters; alternatives for reducing, mitigating, and controlling
hypoxia; and the social and economic costs and benefits of such
alternatives.” The Assessment further supports initial Congressional
findings that a significant factor causing or contributing to harmful
algal blooms may include excessive nutrients in coastal waters,
and also, that harmful algal blooms and blooms of non-toxic algal
species may lead to other damaging marine conditions, such as hypoxia
(reduced oxygen concentrations), which are harmful or fatal to fish,
shellfish, and benthic organisms.
"Predicting
the response of Gulf of Mexico hypoxia to variations in Mississippi
River Nitrogen Load" by Donald Scavia, Nancy Rabalais, Eugene Turner,
Dubravko Justic, and William Wiseman, Jr.
- The
effect of nutrient loading from the Mississippi Basin on the areal
extent of the Gulf of Mexico Hypoxic Zone is investigated using
a dissolved oxygen model. Results suggest that a 30% reduction in
nitrogen loads may not be sufficient to reduce the average size
of the hypoxia zone to 5,000 km2.
"Nitrogen in the Mississippi Basin--Estimating Sources and Predicting
Flux to the Gulf of Mexico" by Donald A. Goolsby and William A.
Battaglin.
- A summary of important results from the Task
Force Science Assessment Topical Report 3 and from more recent
analysis of the relations between the flux of nutrients from the
Mississippi River and the extent of the hypoxic zone in the Gulf
of Mexico.
"Eutrophication: Nitrate flux in the Mississippi River"
by Gregory McIsaac, Mark David, George Gertner, and Donald Goolsby.
A "brief communication" published in Nature(Nature 414, 166-167
(2001)).
- Their analysis indicates that a 12% cut in fertilizer use over
the 1960-98 time period, could have reduced nitrate flux to the
Gulf of Mexico by 33%. Abstract
"Nitrogen Input to the Gulf of Mexico" by Donald Goolsby, William
Battaglin, Brent Aulenbach, and Richard P. Hooper was published in
the Journal of Environmental Quality(JEQ 30, 329-336 (2001)).
Abstract
"Long-Term Changes in Concentrations and Flux of Nitrogen in the Mississippi
River Basin, USA" by Donald Goolsby and William Battaglin, published
in Hydrological Processes(HP 15, 1209-1226 (2001)). Abstract
Both articles indicate that
- The flux of nitrate from the Mississippi River to the Gulf of
Mexico has nearly tripled in the last 30 years.
- The principal source areas of that nitrate are streams draining
largely agricultural watersheds in southern Minnesota, Iowa, Illinois,
Indiana, and Ohio.
"Isotopic and Chemical Composition of Inorganic and Organic Water-Quality
Samples from the Mississippi River Basin, 1997-98" by William
Battaglin, Carol Kendall, Cecily Chang, Steve Silva, and Donald Campbell,
published as U.S. Geological Survey Water-Resources Investigations
Report 01-4095.
PDF of report.
- The report describes the use of δ15N and δ18O
isotope ratios of dissolved nitrate in water samples from the
Mississippi River and its tributaries to determine the sources
and transformations of that nitrate as it moves to the Gulf of
Mexico.
"Chemical and isotopic evidence of nitrogen transformation in
the Mississippi River, 1997-98" by William Battaglin, Carol Kendall,
Cecily Chang, Steve Silva and Donald Campbell, published in Hydrological
Processes (HP 15, 1285-1300 (2001)). Abstract.
- Results in this paper suggest that in-stream assimilation and
not denitrification accounts for the small amount of nitrate loss
in the lower Mississippi.
Hypoxia Assessment Reports Available
The Task
Force Science Assessment Topical Report 3 is now available on
the USGS web site as a PDF file. This is one of six reports prepared
for the White House Office of Science and Technology Policy as part
of a science assessment of hypoxia in the Gulf of Mexico. Go to the
National
Ocean Service home page for more information. |