Southeastern is no stranger to the marsh in the Lake Maurepas and Pass Manchac areas. In fact, the biology department has conducted many projects over the last few decades to study the decline of the area.

The problem was brought to light several years ago through the research of scientists, including Southeastern Professor of Biological Sciences Gary Shaffer. Shaffer has been studying Louisiana wetlands for years and has compiled a significant body of research on the impacts that logging of native trees, erosion, nutrient starvation, saltwater intrusion, herbivores such as nutria, and other factors are having on the deterioration of wetlands of southeast Louisiana.

He explained that the establishment of levees over the last century along the Mississippi River to eliminate natural flooding removed a once reliable source of fresh water, sediments, and nutrients that swamps require for healthy growth.

“This has enabled saltwater from the Gulf of Mexico to make further inland intrusions,” he said. “Combined with rising sea levels and the construction of massive canals, such as the Mississippi River Gulf Outlet (MRGO), the intensity and frequency of saltwater intrusions has only grown worse. Consequently, most of the Maurepas Swamp appears to be in transition to marsh and open water.”

The findings are based on comparisons of selected groupings of sites in the southern wetlands of Lake Maurepas. The sites had three different levels of water quality: including stagnant and nearly permanently flooded areas, sites with severe saltwater intrusion, and sites that receive some freshwater runoff. Salinity levels appeared to be the major factor causing sites to rapidly deteriorate, with the most degraded areas located near Lake Pontchartrain or along the margin of Lake Maurepas.

Recently, Gerard Blanchard, professor of physics and undergraduate coordinator, and Southeastern physics / electrical engineering dual degree student Fawaz Adesina have joined in the research efforts to study groundwater salinity in the Turtle Cove area, located on Pass Manchac between lakes Pontchartrain and Maurepas. Encouraged by Rob Moreau, manager of Southeastern’s Turtle Cove Environmental Research Station, and aided by two grants through the Southeastern Center for Faculty Excellence, Blanchard and Adesina designed and installed at Turtle Cove the first of four groundwater salinity monitors that will be deployed in a line that is perpendicular to Pass Manchac. The monitors take daily readings at three different depths—10 cm, 20 cm, and 50 cm—to get a two-dimensional view of the salinity profile. “This improves on the current method, which uses manual weekly readings that do not distinguish the variations in salinity with depth,” Blanchard said. “The scientific goal is to build a physical model of the salt transport.

Blanchard has been collaborating with Shaffer on the project. Shaffer currently has wells in the marsh, where salinity levels are checked once a week to study the health of the marsh. “The higher the salinity levels in the marsh, the harder it is for things to grow, or for what used to be out there to grow,” said Blanchard. “Getting the salinity down is a big part of the restoration efforts.”

Blanchard said an equation is used to measure how the saltwater flows from one position to another and up and down. The data collected will hopefully identify the factors that cause the salt levels to change at different locations and help scientists determine if the levels are getting worse. Scientists are working on diverting the water from the Mississippi River into Lake Maurepas that will then flow through that area to try to preserve the marsh.

“When we get our information, we are going to try to fit the data with this equation. There are some unknowns and some constants that specify the exact type of soil, the sources, and how much evaporation exists,” Blanchard said. “With the data, we can specify the equation to that particular time and place. If we do it well, we can use that to predict future levels.”

Blanchard said the educational goal of the project is to give Adesina practical experience with electronics, instrument calibration, data analysis, and presentation of results. Adesina gained more experience than he bargained for with this project. Originally from Kenya, it was his first time in a boat when they installed the instrument.

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“I was not prepared for that journey,” Adesina said. “It was a cold morning and we were on a boat in the middle of a cold lake going at high speed. The blowing air froze my face, my nose was running and my fingers were so cold. But the opportunity of installing a device that I helped build was worth the whole experience.”

Adesina also expressed his excitement about the project helping prepare him for a career in his field.

“As a student, this project is an opportunity for me to prepare for the real world and to gain some research background,” he explained. “The knowledge of the electronics part of the project will be immensely helpful to me in my engineering classes and labs. The project also put me on the path of finally overcoming my fear of coding.”

The project, Adesina said, has not only helped him academically, but personally as well.

“I have learned to ask questions when I don’t understand things; I never used to ask questions,” he said. “It has taught me that patience is the key to success—or you’ll get burned by a soldering iron. This project has given me many experiences that I would not have gotten in a class, and that is the main purpose of working on research as an undergraduate. It is the extracurricular activities that help you in class and help you
decide what you want to do in the future.

“Southeastern has a way of making you feel at home, while also training you to venture into the real world and how to communicate with people from different backgrounds and break down barriers,” he said. “Through conferences, on-campus job interviews, seminars, and even talking to professors on campus, my communication skills, as well as my people skills, have improved.

“I have always loved to take things apart and see how they work, and the chance for me to actually build something with my own hands is like a dream come true.”

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Student Fawaz Adesina (front) and Physics Professor Gerard Blanchard (back) install a groundwater salinity monitor in Pass Manchac.
By Tonya Lowentritt

One thought on “Saving Our Swamp

  1. Monitoring Louisiana’s ecological communities now will provide valuable data as climate change continues. Those communities within 100 miles of the Gulf will be heavily impacted so studies like these are basic for developing future models.

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