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Impact of Mississippi River

Full Title: The central role of the Mississippi River and its delta in the oceanography and ecology of the Gulf of Mexico large marine ecosystem

This project provided the resource management community with information on how annual and seasonal flow patterns of the Mississippi River impact the salinity distribution of the Mississippi River Delta and the northern Gulf of Mexico surface waters.  

The Team: Alexander Kolker (Lead Investigator, Louisiana Universities Marine Consortium,, Brian J. Roberts (Louisiana Universities Marine Consortium), Alisha Renfro (National Wildlife Federation), Philip Chu (NOAA), Natalie Peyronnin (Environmental Defense Fund), and Caz Taylor (Tulane University)

Technical Monitor: Caitlin Young ( and Kate Rose (

Federal Program Officer/Point of Contact: Frank Parker (

Project Timeframe: September 2015 to August 2018.

Award Amount: $309,276

Why it matters: While it is well known that the Mississippi River is the largest source of freshwater, nutrients and sediments to the Gulf of Mexico, and that its delta is a major habitat for ecologically and economically important species, many elements of river/delta/ocean interaction are still poorly understood.

What the team did: This project investigated the influence of the Mississippi River and its delta on the oceanography, ecology, and economy of the Gulf of Mexico. The project was broken into two management objectives; (1) to identify the gaps in data collection, model availability and model integration that currently prevent managers from sustainably managing the Gulf ́s natural resources; and (2) to model long term trends of Mississippi River discharge direction patterns (N, E, W, S) and investigate how changes in River discharge location due to climate change may impact the ecology of the coastal zone. 

Investigators did a data synthesis of information from across the Gulf and by convening a working group that solicited opinions and information from experts from across the Gulf and the nation in order to achieve management objective 1. The panel expertise covered physical, chemical, atmospheric, benthic, fisheries, marine mammal, economic and human dimension knowledge of the Gulf of Mexico ecosystem. To achieve management objective 2, investigators compiled historical outputs from physical oceanographic models to provide an overview of the Gulf of Mexico and the role of riverine and deltaic forcings. For this objective, the investigators examined the variability of Mississippi River discharge, changes in the direction of river plume, variability in coastal currents, and extreme weather events (cold fronts and hurricanes).

Project Outputs and Outcomes: The project produced two peer reviewed papers and a web tool. The first paper, “Rethinking the River”  describes how developments in data collection and analysis, coupled with advances in numerical modelling are changing the ways that the scientific community views the Mississippi River, its Delta, and their impacts to the Gulf of Mexico. The paper was published in the peer- reviewed, open access format journal, “Eos,” of the American Geophysical Union in June 2018The second paper is titled “The Central Role of the Mississippi River and Its Delta on the Oceanography, Ecology and Economy of the Gulf of Mexico: A Modern Synthesis,” and is under review in at the journal ‘Oceanography’. 

Finally, an outreach website was developed which houses interactive conceptual models developed by the expert panel data synthesis, the salinity tool, two white papers, and the glossy report. This material can be found here: Additionally, a short video was made about the project, and that summarizes the project activities. 

Management Impact: Investigators identified where additional data collection and computer modeling can help resource managers better understand the Mississippi River and its impacts to the Gulf.