Barataria Bay is a marshy jewel in the heart of the vast Louisiana bayou. Its unparalleled natural ecosystem was once a hideout for smugglers and malcontents like Jean Lafitte, who ruled the labyrinth of marshlands and estuaries. By the early 20th century, oil and gas had taken over the marshlands, and levees reined in the mighty Mississippi River and redirected it toward the Gulf of Mexico.  

Now, pipelines and canals crisscross the bayou, but the 15-mile Barataria Bay that runs along the Mississippi River remains one of America’s richest fishing grounds, with an abundant assortment of shrimp, crab, oysters and commercial seafood that’s a big part of the state’s $2.4 billion fishing industry today.

As the fisheries expanded, Mississippi River levees constructed in the early 1900s stemmed the flow of natural land-building river sediment into the bay. The levees, along with oil development and sea-level rise due to climate change, contribute to one of the greatest land-loss rates on the planet: Land in Barataria Bay is disappearing under the rising tides at the rate of a football field every 100 minutes.

This article contains images of dead wildlife that some viewers may find upsetting.

Barataria Bay is also at the center of one of the biggest natural construction projects in history — a $50 billion plan to reverse this land loss that has pitted powerful state agencies and national environmental organizations against commercial fishing groups and independent marine mammal scientists worried about impacts on fisheries and wildlife. 

Stuck in the middle of this fight are two major populations of northern Gulf bottlenose dolphins.

The dolphins long flourished in the brackish waters of Barataria Bay and the Mississippi Sound. But the changing climate, pollution, and a flood of diverted Mississippi River water, which reduces salinity and increases nutrients, now imperil them. Last year, a record-setting torrent of river water led to a toxic algal bloom that left ocean waters in Mississippi off-limits for months last summer and were linked to painful, often deadly skin lesions on the dolphins. 

This week, federal officials closed their investigation of the more than 330 dolphin deaths last year, connecting the animals’ demise to low salinity levels caused by record flooding that poured trillions of gallons of nutrient-rich fresh river water into the Mississippi Sound and other coastal regions. Scientists say it’s likely to be a recurring nightmare as climate change increases rainfall and flooding along the Mississippi River and in the upper Midwest.  

The surge of river water may only get worse as Louisiana plans to build huge, land-building sediment diversions on both sides of the Mississippi River. Though smaller river diversions have been used to build up land for centuries, there’s never been an attempt on this scale or designed with this kind of modeling technology. The diversions will each pour as much as 75,000 cubic feet a second of sediment-laden Mississippi River water into the marshes in a massive attempt to build land. 

Barataria Bay’s 2,300 dolphins are especially vulnerable to river diversions, scientists say, because their health was so severely damaged in the 2010 Deepwater Horizon disaster 40 miles off the coast. Due to tidal action, a significant amount of BP’s oil and dispersant mix poured into Barataria Bay, which scientists say wiped out half the bay’s dolphin population. 

The dolphins that are left are still struggling, and their health will take decades to recover. Marine mammal scientist Lori Schwacke of the Marine Mammal Foundation published studies that found significant lung disease, reproductive problems, and in some cases, worsening health of the bay’s dolphins. She is worried about the potential harm a flood of freshwater could cause those populations.

“When the diversions happen, dolphins will still be in the early stages of recovery. Freshwater could kill hundreds of dolphins,” she said. “We don’t see any evidence they will move.” 

The legal settlements with BP directed billions of dollars to Louisiana to fight coastal erosion. The state has earmarked $1.4 billion to design a mid-Barataria Bay diversion on the west side of the Mississippi River, and it is in the early stages of designing another $800 million Breton Sound sediment diversion in St. Bernard Parish on the west side of the river. 

While these two sediment diversions are just a few of the hundreds of dredging and restoration projects in the state’s extensive coastal restoration master plan, they are two of the most important and most controversial.

Fishing groups, marine mammal scientists and community leaders have strongly objected to untested diversion projects of this scale, which they worry will flood the bayou with river water that carries nitrogen, fertilizers and chemicals that drain down from 31 states. They say the influx of water will kill off marsh grass and change salinity levels to a point at which the rich shrimp, oyster, crab, and dolphin populations will not survive. 

“It is ironic that the state of Louisiana received billions of dollars in compensation from BP for damages to its ecosystem, including endangered sea turtles and dolphins, and it now wants to negatively impact the same ecosystem and dolphins that they accused BP of harming in the first place,” said Moby Solangi, the president and executive director of the Institute for Marine Mammal Studies in Gulfport, Mississippi. “Not only will we lose the dolphins, but there will be a collapse of the ecosystem and its associated fisheries.”

Many residents of the fishing communities bordering the planned diversions worry their future is at stake, too. 

Capt. George Ricks, a charter fisherman in St. Bernard Parish and president of the Save Louisiana Coalition, said the fishermen his group represents have long opposed the diversions.  

“All the other states are using BP money to help their fisheries,” Ricks said as he prepared to head out on his boat to inspect oyster reefs in St. Bernard Parish with other commercial fishermen. “Louisiana is using the money to destroy them.” 

Ricks says Exhibit A of that destruction is the state’s successful 2018 effort to get a rare congressional waiver for the Marine Mammal Protection Act, or MMPA, the comprehensive federal law that forbids harming, harassing or “taking” marine mammals such as dolphins.

The unusual waiver was part of a state-funded effort by the Washington, D.C.-based environmental lobbying firm Van Ness Feldman. Two of the firm’s top lobbyists, former Louisiana Sen. Mary Landrieu (D) and aide to former Sen. Bennett Johnson (D), Bob Szabo, published an article in June 2018 explaining how they successfully solved Louisiana’s “Marine Mammal Protection Act Problem.” 

“Without such a waiver, the project could not move forward,” they wrote. “Therefore, we were forced to approach Congress” to come up with “a very narrow amendment” with the assistance of “several national environmental and conservation NGOs.”

That amendment was inserted into the Bipartisan Budget Act in February 2018, just four days after the U.S. Marine Mammal Commission sent a strong letter of concern to a federal oil spill advisory group, noting that the health of the bay’s dolphins “is already compromised” from the spill and that “such projects have the capacity to injure marine mammals” in violation of the federal law.

According to participants in the waiver negotiations, several NGOs did support the waiver. But many did not ― including marine mammal scientist Naomi Rose with the Animal Welfare Institute. Rose said that getting an MMPA waiver established a “very troubling” precedent, as it was the first successful MMPA waiver that was not later overturned by the courts, “circumventing the careful process” Congress had put in place when it passed the act in 1972. 

“Doing it by a rider in a spending bill is not a precedent we wanted to see happen — other far less conservation-minded actors might seek the same kind of waiver, which could quite frankly be disastrous for marine mammals,” Rose said. 

A coalition of groups called the Restore the Mississippi River Delta ― which includes the Environmental Defense Fund, the National Wildlife Federation, the Audubon Society, the Lake Pontchartrain Basin Foundation and the Coalition to Restore Coastal Louisiana ― supported the waiver because they see river sediment diversions as a crucial way to solve the complex coastal erosion problem. 

The coalition has produced a variety of scientific white papers, economic studies and multimedia presentations on the topic of coastal restoration with the support of the Walton Family Foundation, the philanthropic arm of the family that founded Walmart. The foundation has also funded coastal reporting for the New Orleans Times-Picayune, The Lens and New Orleans public radio station WWNO. 

River diversions are the most efficient way to save the Louisiana bayou, said Steve Cochran, EDF’s associate vice president for coastal resilience and a New Orleans area native. Cochran says the environmental groups that backed the waiver had a good working relationship with the state and worked hard to come to an agreement with federal agencies such as the National Oceanic and Atmospheric Administration to negotiate an administrative process for river diversions, but it became clear there was no quick solution if dolphins could be harmed. Cochran says his coalition believed there was no time to waste given rapid coastal erosion taking place across the region.

When the state decided to push for a congressional waiver, it was an “uncomfortable place to be,” Cochran said, because marine scientists opposed going that route. But Cochran said the groups made sure the waiver required the state to come up with a “marine mammal science plan” to minimize and monitor the effects on dolphins and marine mammals. 

David Muth, National Wildlife Federation’s director of Gulf restoration and also a New Orleans native, has worked closely on many aspects of the state’s coastal restoration plan, including potential effects on dolphins. He said the BP money was a “game changer” for Louisiana’s comprehensive restoration plans. “The purpose of the act is the long-term health of marine mammals,” he said. “And the only way to do that is to build diversions to save southeast Louisiana.” 

Muth, who is not a marine mammal scientist, and his coalition colleagues submitted a memo to NOAA in 2016 arguing that dolphin populations could be harmed more in the long term by not building the river diversions: “We are concerned that a failure to think more broadly and confront on-going deltaic land loss and climate change by implementing sediment diversions will actually result in greater jeopardy to dolphins, and to a host of other wildlife and fishery resources, industries, communities, and people,” the memo stated. 

Louisiana state officials acknowledge river diversions could cause short-term harm to dolphin populations, but they say they are working closely with federal officials on a plan to monitor and protect marine mammals from the influx of river water, which they say will be part of the Environmental Impact Statements required by law. The EIS of the Mid-Barataria sediment diversion is expected in March 2021.  

“We’re working very closely with NOAA evaluating potential impacts of the projects to marine mammals,” said Bren Haase, Louisiana Coastal Protection and Restoration Authority’s executive director, in his Baton Rouge office, where the agency has built a 10,000-square-foot computer-enhanced model to explore diversion impacts on the bayou ecosystem. “That’ll be disclosed, and potential mitigation will be part of the EIS as it relates to those.” 

NOAA officials did not comment on the agency’s marine mammal monitoring and mitigation plans with the state. 

Federal agencies have a “myopic view” of the MMPA, said Chip Kline, the Louisiana Coastal Protection and Restoration Authority’s chairman and executive assistant to the governor for coastal activities. “We’re not building strip malls,” Kline said. “These are projects that will benefit the species in the long term.” 

Critics of the process point out that the former executive director of the Louisiana CPRA, Johnny Bradberry, is now running the engineering company that is doing the third-party environmental review. The CPRA requires that Bradberry be “walled off” from doing work on the authority’s contracts to avoid any conflicts of interest. 

Still, some groups are worried that dolphin waiver sends the wrong message. “This and any other waiver set a very bad precedent — setting the stage for other federal and state agency requests for waivers when they feel that a consultation on a species or compliance with the law would hinder construction of a project,” said Cyn Sarthou, the executive director of Healthy Gulf, a Louisiana nonprofit that works on environmental issues.

Solangi agrees: “The waiver was a political decision. It was not based on scientific information or properly vetted through public hearings or other required procedures.”

Louisiana Lt. Gov Billy Nungesser, president of hard-hit Plaquemines Parish during the BP spill, opposes the river diversions, which he considers a threat to fishing communities along the bayou. Nungesser said despite all the talk about science, money has overtaken the state’s coastal restoration process.

“People are worried more about construction contracts before there’s an environmental impact statement,” he said. “We’re going to destroy one of the richest estuaries in the world, and the seafood industry with it.”