Exploring the Connections between the Mississippi River and the Gulf of Mexico

03.06.2019 | In Science
By Alisha Renfro, Coastal Scientist, Mississippi River Delta Restoration Program, National Wildlife Federation

The Mississippi River has long been recognized as an important influence to the Gulf of Mexico, but to date, there have been few efforts to effectively summarize all the ways the river impacts the larger Gulf ecosystem. With funding from the NOAA RESTORE Science Program, a working group of scientists came together to analyze what is known – and what remains unknown—about the effects the Mississippi River and its delta have on the Gulf to help guide decision-makers as they advance key restoration efforts.

The working group developed a series of interactive conceptual models to show the many complexities in the relationship between the river and the Gulf, to help users explore and experience this dynamic ecosystem – how they interact, how they share resources and how the health of the Gulf depends on the health of the Mississippi River and its delta.

The Water Column

The Mississippi River and its major distributary, the Atchafalaya River, deliver large amounts of fresh water, sediment and nutrients to the Gulf of Mexico, having wide-ranging and far-reaching influence on the Gulf’s water column – from the surface to the seafloor.

Did you know the river’s plume of fresh water can cover as much as 14,500 square miles of the Gulf?1 Learn about how the Mississippi River Delta interacts with swimming animals and nutrients as well as how hurricanes influence hypoxia through our interactive graphic.

Click on the image to open the interactive

The Benthic

The total influence of the river on the sea floor is hard to evaluate, but we do know that the mineral sediment and organic matter from the river provides habitat and food sources to the seafloor.2

Learn about how the river impacts everything from the microbiota to the deep-sea corals in the benthic zone by clicking on the connections in the interactive graphic.

Click on the image to open the interactive

Deltaic Estuaries

The estuaries of the Mississippi River Delta were built and shaped over time by the river and the Gulf. Modifications to the river, including control structures, damming of distributary channels and the construction of levees, have largely reduced the amount of sediment and fresh water that flows into many of the delta’s estuaries; but these estuaries still serve as an important influence to the Gulf as sources of fresh water.3

These estuaries also provide important spawning, growth and feeding habitat for various fish and other organisms that move between the estuaries and the Gulf, including most of the Gulf’s most important commercial and recreationally valuable species.

Learn how the lack of sediment influences the estuary and how freshwater diversions influence the deltaic system by reviewing the interactive graphic.  

Click on the image to open the interactive

Human Influences

Human changes to the way the Mississippi River and its delta influence the Gulf of Mexico have been widespread, having both intended and unintended consequences. Explore our final interactive graphic to better understand how we have changed the Gulf of Mexico.

Click on the image to open the interactive


References

1 Fitzpatrick, C., A. S. Kolker, and P. Chu. 2017. “Variation in the Mississippi River Plume from Data Synthesis of Model Outputs.” OS23A-1379 presented at the American Geophysical Union, Fall Meeting, New Orleans.

2 Rowe, G., C. Wei, C. Nunnally, R. Haedrich, P. Montagna, J. Baguley, J. Bernhard, et al. 2008. “Comparative Biomass Structure and Estimated Carbon Flow in Food Webs in the Deep Gulf of Mexico.” Deep-Sea Research II 55: 2699–2711.

3 Feng, Z., and C. Li. 2010. “Cold-Front-Induced Flushing of the Louisiana Bays.” Journal of Marine Systems 82 (4): 252–64.