This summer’s “dead zone,” a low-oxygen area where the river empties into the sea, could
span 5,827 square miles across the Gulf of Mexico. Louisiana has the power to call for change.
This story is part of the series Farm to Trouble from the Mississippi River Basin Ag & Water Desk, an independent reporting collaborative. Read other stories in the series here.
By Delaney Dryfoos, The Lens
CYPREMORT POINT, La. — Thomas Olander has watched his shrimp catch shrink over the
last 15 years. It’s not just the abundance of Louisiana shrimp; Olander said that the average
size of the crustacean has also shrunk.
In the past, shrimpers could expect the crustaceans to grow throughout the spring season,
which starts in May in Louisiana waters and generally runs through July. “Since we’ve been
dealing with this ‘dead zone,’” said Olander. “We’re not seeing that growth no more.”
The dead zone is a stretch along the shallows of the Gulf of Mexico where algae blooms choke
off oxygen in the water.
This month, the National Oceanic and Atmospheric Administration (NOAA) estimated that this
summer’s dead zone would reach 5,827 square miles – an area roughly the size of Connecticut.
That’s up from approximately 3,058 square miles in 2023.
These massive algae blooms are caused by nutrients that run off of farms up and down the Mississippi River Basin, which stretches from Northern Minnesota to the Gulf of Mexico. Fertilizer that helps crops grow contains high levels of nitrogen and phosphorus. These nutrients run off the fields during rainstorms at the end of the growing season and end up in waterways leading to the Mississippi River.
In 1996, the dead zone in the Gulf of Mexico came to national attention through local reporting.
The Gulf of Mexico Hypoxia Task Force was established in the fall of 1997 – a collaboration of state, federal and tribal agencies – and asked the group to create and implement an action plan.
A preliminary goal is to reduce both nitrogen and phosphorus by 20 percent by 2025. But despite some progress, the task force has not yet met its goals.
The U.S. Geological Survey showed that in May 2024, while nitrogen loads in the lower Mississippi River were 7 percent lower than baseline measurements, phosphorus loads increased by 22 percent.
The 2025 target is simply not a priority for the task force, said Doug Daigle, a research scientist
at Louisiana State University and coordinator of the Louisiana Hypoxia Working Group. He added that neither the task force nor Louisiana attempted to raise funds from Congress to implement programs that would reduce nutrient pollution.
“It’s a problem with the task force, not just Louisiana. There has not been an organized attempt
to garner more funding for the action plan,” said Daigle.
Where is the Clean Water Act?
The task force’s action plan is hindered by a lack of enforceable limits on nitrogen and phosphorus, according to the Tulane Institute on Water Resources Law and Policy. Instead, it
focuses on voluntary state efforts and guidelines.
In a presentation to the Louisiana Governor’s Advisory Commission on Coastal Restoration,
Protection and Conservation in early June, Daigle said the state has been a passive and largely
silent member of the task force.
Daigle said the 176-page strategy is not technically a strategy because it doesn’t have any
targets or goals. He added that the state has missed years of opportunity to reduce the dead
zone.
To address the sheer quantity of nutrient pollution from the upriver basin states, Tulane lawyers
suggest that Louisiana could petition the U.S. Environmental Protection Agency for greater enforcement under the Clean Water Act.
One section of the law allows for the government to set specific, maximum amounts of daily
pollutants for bodies of water deemed to be impaired. Louisiana could petition the EPA to declare sections of the Mississippi River or the Gulf of Mexico as impaired, which would allow
for the creation of an enforceable limit on nutrients entering the river upstream.
Louisiana could also petition the EPA administrator to convene an interstate water management
conference to address pollution upriver. While the Gulf Hypoxia Task Force currently acts as a
mediary between states, it lacks the enforcement power that the Clean Water Act could provide.
But the state has so far not done any of this. Louisiana Gov. Jeff Landry’s office did not respond
when asked if Landry has any plans to petition the EPA or address the growth of the dead zone.
In 2016, the Gulf Restoration Network sued then-EPA administrator Lisa P. Jackson for the agency’s “hands-off approach” to dealing with nitrogen and phosphorus pollution under the Clean Water Act. This lawsuit followed a petition submitted by several environmental non-profits
in 2008 that demanded numeric water quality standards be set for the nutrients. But ultimately, the Eastern District of Louisiana court ruled that the EPA could continue a voluntary approach to nutrient reduction.
In 2019, when the most recent version of Louisiana’s nutrient reduction and management strategy was released, Mark Davis, director of the Tulane Institute on Water Resources Law and
Policy, submitted recommendations for improvements to the Louisiana Department of Environmental Quality (LDEQ).
Davis wrote that it has become clear that neither the EPA nor the task force would be implementing numeric targets any time soon. Those specific, enforceable limits would not be
forthcoming “until Louisiana makes their development a priority and focuses the issue on upstream states and the federal government,” he wrote.
“They did not make a dent,” Davis said.
‘The solution to pollution is not distribution’
As Louisiana works to review its Nutrient Reduction and Management Strategy, some critics say
that the state focuses too heavily on plans to redirect the flow of the Mississippi River. The Coastal Protection and Restoration Authority (CPRA) highlights the benefits that would come from plans to reconnect the river to land across the coast.
“CPRA is constructing diversions with the main purpose of building and sustaining Louisiana’s
coastal wetlands,” said Angelina Freeman, a research scientist at CPRA who was a member of
the Louisiana Nutrient Reduction and Management Strategy interagency team. She explains that by redirecting the river’s flow, nutrients that would have otherwise fueled the dead zone would instead nourish the state’s recovering wetlands.
A few man-made diversions are already up and running, such as the Caernarvon and Davis
Pond Diversions. Davis Pond is restoring wetlands in the upper Barataria Basin on the west side
of the Mississippi River near Luling, in St. Charles Parish, Louisiana, while Caernarvon delivers
sediments and nutrients to Breton Sound on the river’s east bank in Plaquemines Parish.
The 2023 Louisiana Coastal Master Plan calls for redirecting sediments and nutrients into
Barataria Bay on a massive scale through the largest single restoration project in U.S. history.
The Mid-Barataria Sediment Diversion would build and nourish up to 27 square miles of coastal
wetlands over the next 50 years.
But to Daigle, centering the state’s nutrient reduction and management strategy around
sediment diversions such as the yet-to-be-built Mid-Barataria is a mistake.
“Until [the diversions] are built and operating they don’t do anything, good or bad,” he added.
“Talking about them doesn’t accomplish anything. Having them in a plan doesn’t accomplish
anything.”
“The solution to pollution is not distribution,” said Nancy Rabalais, a professor at Louisiana State
University who, for years, led Gulf research cruises to monitor the size of the dead zone. Rabalais and fellow LSU researcher R. Eugene Turner published a separate June 2024 dead zone forecast that was less dire than the above-average estimate released by NOAA. Their prediction looks at the potential effects of warmer water on oxygen levels.
They emphasize that their reduced forecast is “solely due to ocean warming, not to a decline in
nitrate loading from the Mississippi River.”
Cutting down on nutrients within Louisiana
While the vast majority of nutrients that create the dead zone every summer come from
agriculture in the states upriver from Louisiana, there is still a significant input of runoff from
farmland within the state itself.
In 2022, the LDEQ published a report on long-term nitrogen and phosphorus trends at ambient
water quality monitoring stations across the state. They found that nutrient concentrations are
decreasing at the majority of testing locations.
Following these trends, Louisiana received a recent influx of funding to further reduce nutrient
runoff within the state from the Gulf of Mexico Division of the EPA.
Earlier this year, the Gulf of Mexico Alliance received a grant to help farmers in northeast
Louisiana adopt practices to prevent excessive runoff from entering the Bayou Lafourche
watershed, and ultimately the Red River and Atchafalaya Basin.
The Atchafalaya River siphons off 30% of the Mississippi River’s flow. The Atchafalaya has a
growing delta system, such as at the Wax Lake Outlet, but excess nutrients still escape to the
Gulf of Mexico, expanding the dead zone to the west.
In Morehouse Parish, farmers are being taught how to limit their contribution to nutrient runoff
that would reach the Gulf through the Mississippi-Atchafalaya Basin. The grant will fund new
farming techniques, including the subsidizing of cover crops to reduce runoff, which may also
increase soil productivity and cash crop yields.
“We’re doing exactly what we hope and wish everyone north of us would be doing,” said Joey
Breaux, assistant commissioner of the Louisiana Department of Agriculture and Forestry. He
added that the farmers in Morehouse Parish have been very receptive to the new program.
The $1.4 million grant will run through 2026 with the specific goal of reducing the Gulf of
Mexico’s dead zone.
The funds will go to help farmers plant cover crops in between growing seasons to reduce soil
erosion and prevent nutrients from running off into the river. The farmers will also receive
instruction in no-till management, which calls for crops to be planted in narrow rows within the
untilled seedbeds of previous crops. Keeping the soil intact increases organic matter and
productivity while reducing the need for excess fertilizer.
Olander, the shrimper, said that he wishes the Department of Wildlife and Fisheries would
support his industry’s losses in the way that they are for farmers. “They are really keeping their
farmers going,” he added. “Call me a farmer of the sea; I’ll take that title if they would help us.”
What to expect from the next dead zone tour
On July 21, the R/V Pelican will set sail to take stock of this summer’s dead zone. NOAA will
fund a six-day tour of the traditional hypoxic area to the west of the Mississippi River, where the
Atchafalaya River also dumps nutrient runoff into the Gulf of Mexico.
This year, the cruise will be extended for four extra days to tour the area east of the Mississippi
River. This portion of the cruise will be funded by a grant distributed by the Gulf of Mexico
Alliance from the Bipartisan Infrastructure Bill.
And that tour may bring new scientific research to be considered before Louisiana issues its
five-year update to the state nutrient reduction strategy.
“This strategy is up for revision,” said Daigle, “I think it needs a total revision, not just tweaking.”
This story is part of the series Farm to Trouble from the Mississippi River Basin Ag & Water
Desk, an independent reporting collaborative.
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