Nancy Rabalais
Professor and Shell Endowed Chair in Oceanography and Wetland Studies Louisiana State University
- Baton Rouge LA
Dr Rabalais researches dead zones in the marine environment and is an expert in eutrophication and nutrient pollution
Areas of Expertise
Biography
Research Focus
Gulf of Mexico Hypoxia & Coastal Oceanography
Dr. Rabalais’s research focuses on coastal oceanography and marine ecology, with emphasis on Gulf of Mexico hypoxia, nutrient enrichment, and ecosystem responses to land–sea change. She uses long-term shelf surveys, water-column biogeochemistry, and coupled watershed–ocean analyses to diagnose drivers, forecast fisheries impacts, and inform nutrient-reduction policy.
Education
Texas A&I University
B.S.
Biology
1972
Texas A&I University
M.S.
Biology
1975
The University of Texas at Austin,
Ph.D.
Zoology
1983
Accomplishments
Sustaining Fellow
2017
Association for the Sciences of Limnology and Oceanography
Faculty Achievement Award
2023
LSU SEC (Southeastern Conference)
Lifetime Achievement Award
2023
Barataria-Terrebonne National Estuary Program
Media Appearances
Size of 'dead zone' in the Gulf expected to be about average this year. Funding woes for research and action could be much bigger.
WWNO - New Orleans Public Radio radio
2025-06-12
The National Oceanic and Atmospheric Administration predicts the dead zone will be around 5,500 square miles this summer. Some estimates put it a little smaller, like those from Louisiana State University (LSU) research scientists Nancy Rabalais and R. Eugene Turner. That study predicts the hypoxic zone to be around 4,800 square miles by taking into account how warmer water temperatures have altered the complex food web, helping reduce the dead-zone.
Scientists Alarmed by Enormous Dead Zone in Gulf of Mexico
Futurism online
2024-08-03
“The area of bottom-water hypoxia was larger than predicted by the Mississippi River discharge and nitrogen load for 2024, but within the range experienced over the nearly four decades that this research cruise has been conducted,” Nancy Rabalais, a professor at Louisiana State University and co-chief scientist of the dead zone survey, said in an announcement on Thursday. “We continue to be surprised each summer at the variability in size and distribution.”
Gulf ‘dead zone’ is larger than average this year, the size of New Jersey
Louisiana Illuminator online
2024-08-03
Though the dead zone is larger than NOAA had anticipated with its early-summer forecast, it falls within the range experienced over the last four decades of monitoring, said LSU professor Nancy Rabalais, the co-chief scientist for the research cruise.
The Gulf Of Mexico's Expanding Dead Zone
NPR radio
2019-06-16
NPR's Lulu Garcia-Navarro speaks with marine ecologist Nancy Rabalais about the expanding dead zone that is likely to appear in the Gulf of Mexico because of record Midwest rains.
The Gulf could see one of the largest dead zones in history this year
CNN online
2019-06-10
“We think this will be the second-largest, but it could very well go over that,” said Nancy Rabalais, a marine ecologist who has been studying this phenomenon for over 34 years and who is co-author of the LSU report. She is a distinguished research professor at Louisiana State University and a MacArthur Fellow.
Articles
Coastal wetland restoration through the lens of Odum's theory of ecosystem development
Restoration Ecology2024
Advancing ecological restoration assessments requires a more detailed consideration of species interactions and ecosystem processes. Most restoration projects rely on a few metrics not always directly linked with ecological theory. Here, we used Odum's theory of ecosystem development to assess and compare the ecosystem structure and services of created marshes (4–6 years old) with preexisting, reference marshes in a brackish water region of the Mississippi River Delta. We built ecosystem models for created and reference marshes that integrated large datasets of stomach contents, stable isotopes, and taxa abundances.
Multi‐decadal coastal acidification in the northern Gulf of Mexico driven by climate change and eutrophication
Geophysical Research Letters2024
Coastal waters often experience enhanced ocean acidification due to the combined effects of climate change and regional biological and anthropogenic activities. Through reconstructing summertime bottom pH in the northern Gulf of Mexico from 1986 to 2019, we demonstrated that eutrophication‐fueled respiration dominated bottom pH changes on intra‐seasonal and interannual timescales, resulting in recurring acidification coinciding with hypoxia. However, the multi‐decadal acidification trend was principally driven by rising atmospheric CO2 and ocean warming, with more acidified and less buffered hypoxic waters exhibiting a higher rate of pH decline (−0.0023 yr−1) compared to non‐hypoxic waters (−0.0014 yr−1).
Why are there so many definitions of eutrophication?
Ecological Monographs2024
Because of the first observations in the 1900s of the oligotrophic and eutrophic states of lakes, researchers have been interested in the process that makes lakes become turbid because of high phytoplankton biomass. Definitions of eutrophication have multiplied and diversified since the mid‐20th century, more than for any other ecological process. Reasons for the high number of definitions might be that the former ones did not sufficiently describe their causes and/or consequences. Global change is bringing eutrophication more into the spotlight than ever, highlighting the need to find consensus on a common definition, or at least to explain and clarify why there are different meanings of the term eutrophication.
Bottom water quality plasticity in the northern gulf of Mexico hypoxic zone
Continental Shelf Research2024
The growth of the now ubiquitous hypoxic zones found throughout the global coastal ocean are primarily a consequence of nutrient enrichment in surface waters increasing organic production that sinks into bottom waters where oxygen is depleted faster than it is replenished. Hypoxic zones may increase or decline in number because of future climate changes. Here we summarize the summertime variations of dissolved inorganic silicate (DSi), phosphate (DIP), nitrogen (DIN; nitrate + nitrite and ammonium) and ammonium concentrations in the bottom waters of the northern Gulf of Mexico continental shelf from 1985 to 2022.
A temperature tipping point in hypoxic zone size
Limnology and Oceanography2024
Temperature increases will have ubiquitous effects on aquatic food webs, from microbes to consumers, and affect the quality and quantity of carbon flows within and between water layers. A decline in the biological pump moving carbon from surface to lower layers is anticipated. We reviewed 37 years of data on hypoxic zone size and water quality in the northern Gulf of Mexico to determine if air and bottom water temperature increases (0.5°C decade−1) are significantly related to variations in its areal size. There was no significant decline in important river water quality in the 24 years since the national Hypoxia Action Plan was developed to reduce its size.
Affiliations
- National Academy of Science : Member, Gulf Research Program, Division Committee
- Ecosystem Synthesis Initiative : Member, Science Advisory Committee, NAS Gulf Research Program
Media
