A Vanishing Mississippi River Delta

The Federation and its partners are working to restore critical winter habitat for millions of migratory waterfowl

  • Laura Tangley
  • Conservation
  • Nov 24, 2014

FROM A DISTANCE, it looked as though a huge swarm of insects had just lifted off from the marsh. But as the boat drew closer, the myriad black specks grew larger and resolved into the distinctive shapes of birds: thousands of northern pintails, green-winged teal, northern shovelers and other ducks. “You’re probably looking at 8,000 ducks,” Ryan Lambert of Cajun Fishing Adventures said as he maneuvered his 28-foot, camouflaged craft through the labyrinth of a lush wetland off the Mississippi River near Buras, Louisiana.

Lambert’s estimate was impressive, but not too surprising. As the winter home to more than half of all waterfowl that traverse the Mississippi and Central Flyways, coastal Louisiana hosts between 3 million and  5 million ducks and geese during the cold months. Tom Moorman, southern regional director of Ducks Unlimited (DU), calls this stretch of the Gulf Coast “the single most important winter habitat for waterfowl on the continent. You won’t find larger concentrations of the birds anywhere else in North America.”

Still, Lambert and the duck hunters he takes out each year were disheartened by last winter’s turnout. “The birds showed up late, and there were fewer of them,” he says. Official statistics back him up: Each fall and winter, Larry Reynolds of the Louisiana Department of Wildlife and Fisheries (LDWF) conducts a series of aerial waterfowl surveys along the state’s coast. He says that 2013’s September and November flights yielded “the lowest number of birds recorded since surveys began in 1969.” December numbers also were low, though by January 2014, the count had rebounded to about average. “There were birds in the flyway,” Reynolds says. “They just took their time getting here.”

The birds’ late arrival “had a lot of duck hunters scratching their heads,” says Ben Weber, sportsmen’s outreach coordinator for Vanishing Paradise, a partnership of NWF, DU and Louisiana Wildlife Federation (an NWF affiliate) that works to protect and restore waterfowl habitat in the Mississippi River Delta. Because 2013’s breeding season had gone well and no big hurricanes had ripped up the marsh vegetation that ducks eat, hunters had been optimistic at the start of the season. “We used to be able to predict good and bad years,” Weber says.

New Normal?

According to Reynolds, bad years are becoming more normal. Looking back at LDWF survey data from the past two decades, he says “at least 10 percent fewer ducks and geese of all species winter in Louisiana now than they did 15 to 20 years ago.” Some birds, including mallards and snow geese (above), have dropped to half their former numbers. Because populations in the flyway as a whole have remained stable, Reynolds suspects more birds are now wintering to the north.

He cites several variables that may be contributing to the shift. Climate change, for example, has resulted in warmer winter temperatures and later freezes in northern states. In addition, new rice varieties are allowing farmers to grow the crop farther north than they once could, and some waterfowl species thrive in flooded rice fields.

A more ominous possibility: During the past several decades, the delta (below) has lost vast tracts of coastal wetlands to erosion, virtually all of them former waterfowl habitat. “Good years and bad years for ducks can happen anywhere and anytime for many reasons,” Moorman says. “But when you are losing 16 square miles of duck habitat a year, you are eventually going to lose the ducks as well.”

Habitat Lost

Coastal Louisiana suffers the highest rate of land loss in the nation. Since the 1930s, 1,900 square miles of this biologically rich habitat have been transformed into open water, and today an area the size of a football field is lost every hour. Subsidence and wave erosion contribute to wetlands loss. But humans have greatly exacerbated these natural processes by constructing levees, dams and other structures that prevent the Mississippi River from delivering the soil and nutrients that create new land, as it historically did during annual spring flooding. Thousands of pipelines and canals, meanwhile, speed up the destruction by allowing vegetation-killing salt water into the marshes. “Not only are we destroying our wetlands, we are disrupting the natural cycle that can rebuild them,” explains David Muth, director of NWF’s Mississippi River Delta Restoration Campaign, which works with partners regionally and nationally to restore the coast by reconnecting the river with its delta.

According to a recent calculation by waterfowl scientists, habitat loss means coastal Louisiana today can support some 3 million fewer ducks than it did in the 1970s. But with overall duck numbers 43 percent above their 1955 to 2013 long-term average, according to a July 2014 U.S. Fish and Wildlife Service report, does it matter whether the birds spend winter feeding in a Louisiana marsh or in a rice field in Missouri?

That may depend on the species. “A mallard can fatten up in a dry cornfield, then go sit on a lake to rest,” Reynolds says. But other ducks, including wigeons, scaup and gadwalls, do better with the aquatic vegetation they evolved with, along with the snails, clams and other invertebrates that live in natural wetlands. Says Muth: “The best winter waterfowl habitat on the continent can be found in active delta splays around the mouth of the Mississippi River.”

Fat is Fit

High-quality winter habitat is crucial for waterfowl to build fat reserves they need to survive long migrations to breeding territories. According to DU, ducks use 12 times more energy in flight than at rest, and a single female mallard typically burns about 1.8 million calories during a one-way trip from southern Louisiana to Saskatchewan. If a bird cannot accumulate enough fat during winter, it may leave late to migrate north. Late arrival on the breeding grounds means a female will have lower nesting success than if she had arrived on time. She may even forgo nesting entirely.

“For a bird to successfully reproduce, it must be fit, and for a duck being fit means being fat,” Moorman says. Waterfowl also require fat reserves to survive winter. During the cold months, a mallard, for instance, needs enough stored fat to last five to seven days without eating, Moorman says. “That way, it can wait out a cold snap and still have a fuel tank full enough to go elsewhere if the bad weather doesn’t break.” As evidence that Gulf Coast habitats are suffering, he cites research that found lower survival rates for wintering female northern pintails (below) in southwest Louisiana and coastal Texas than in other regions the birds overwinter.

In the mid-1980s, when pintails and other duck species were declining, the governments of the United States and Canada (joined by Mexico in the mid-1990s) launched the North American Waterfowl Management Plan, an ambitious, long-term effort to restore the continent’s duck, goose and swan populations, primarily by conserving and restoring breeding habitat in the famed “duck factory” of the Prairie Pothole Region. Thanks to these measures, most waterfowl species are stable or increasing today. “It makes no sense not to mount the same kind of effort in the birds’ wintering grounds,” Weber says. “If we keep losing habitat in the delta, it will hurt ducks up and down the flyways.”

Gaining Ground

Fortunately, a large-scale effort to restore Louisiana’s disappearing wetlands is closer to reality today than ever before—and Lambert’s duck-hunting lease near Buras provides an ideal example of how such an undertaking would work. Located about midway between New Orleans and the state’s iconic “bird’s foot” at the tip of the delta, Lambert’s office and lodge lie on a narrow strip of land bisected by Highway 23. On the west side of the highway, where the Mississippi River is hemmed in by levees, there is nothing but open water, all of it formerly wetlands.

To the east and across the river, one of the few stretches of the Mississippi where levees do not stop spring overflow, the scene could be from another planet: Lush, green millet, wild pea and duck potato line serpentine waterways brimming with submerged plants such as pondweed that waterfowl crave during winter. “This is an example of a vibrant, living marsh built and maintained by natural processes,” Weber explained. “The only difference between this side of the road and the other is that the river, along with the sediment and nutrients it carries, replenishes the habitat as it once did throughout the delta.”

For more than three decades, the threat coastal land loss poses to wildlife and human lives has been well recognized, particularly among people like Lambert who live on the front lines. Yet attempts to tackle the problem so far have been small, fragmented and poorly funded. “When you’re losing 16 square miles a year, a half million dollars here and a half million there doesn’t make much of a difference,” Muth says.

But these days, Muth and his colleagues are feeling more optimistic. Four years ago, when the Deepwater Horizon disaster spewed some 185 million gallons of oil into the Gulf of Mexico, national concern about the spill also focused attention on the long-term crisis of coastal land loss. Now, as legal processes move forward to require responsible parties to pay for the oil damage, a large portion of both civil and criminal fines are being directed toward restoration. Particularly encouraging, the RESTORE Act—passed in 2012 after pressure from NWF, its conservation partners and hunters and anglers nationwide—requires 80 percent of U.S. Clean Water Act penalties go to restoring the Gulf Coast, an amount that could total between $4 billion and $20 billion. Already, Louisiana has received $40 million from BP criminal fines to begin constructing what will be the first large-scale, river-diversion project at Myrtle Grove, 35 miles upriver from Buras.

As restoration moves closer to reality, however, opposition is emerging, primarily from those who harvest oysters, speckled trout and some kinds of shrimp, species whose distributions may change as freshwater inflows alter coastal salinity levels. Rather than diverting river water into the system, opponents favor building new land by dredging sand from the bottom. “But without the ongoing input of new sediment, marshes built by dredge, like new cars, begin to depreciate as soon as you get them,” Muth says. He points out that the Mississippi—nicknamed the Big Muddy—carries four times more sediment in suspension than what falls to the bottom. “The river’s suspended sediment, the mud that built the delta, cannot be captured by dredges,” Muth says.

Conservationists acknowledge that some commercial and recreational fishermen will have to adapt to an uncertain future and may experience losses as a result of restoration. But without it, “the fisheries ultimately will collapse,” Muth says. So, too, will critical wetland habitats that support millions of migratory waterfowl—not to mention some 2 million people. Says Lambert: “We are one hurricane away from losing our homes.”

NWF in Action: Restoring Paradise

As a member of the Mississippi River Delta Restoration Campaign, funded by the Walton Family Foundation, NWF’s South Central Regional Center, Gulf state affiliates and Washington, D.C., office have worked for several years with national and regional partners to restore wetlands that are vital not only for waterfowl but for countless other wildlife species as well as human communities.

In another collaboration, Vanishing Paradise, NWF and its partners are working with thousands of sportsmen and women, hunting and fishing businesses and other organizations to restore Louisiana’s waterfowl and fishing habitat by reconnecting the Mississippi River with its wetlands.

A Vanishing Paradise partner and NWF affiliate, Louisiana Wildlife Federation staff and volunteers have played a key role giving voice to the state’s sportsmen by gathering thousands of names of supporters, recruiting 168 businesses and generating more than 100 radio or TV interviews and news articles on the need for coastal restoration. Staff and board members also attend public hearings and work with state and federal agency officials on this critical issue. In addition, LWF has created an army of nearly 7,000 online sportsmen activists supporting coastal restoration through the Louisiana Camo Coalition.

Senior Editor Laura Tangley visited NWF staff and partners in Louisiana to report for this story.

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