Recycling oyster shells into artificial reefs is one tool to slow Louisiana coastal erosion

POINTE-AU-CHIEN, La. (AP) — Cherie Matherne looked out into Bayou Pointe au Chien, wide enough for several boats to pass through. In the distance, a stand of dead trees marked where saltwater comes and goes during storm-driven flooding.

It wasn’t always this way. The bayou was once shallower and just wide enough for a small boat to pass. Land that cattle once roamed is submerged now, and elders tell stories of tree canopies once so lush they nearly shut out the day.

The delicate lattice of Louisiana’s coastline has been steadily retreating for generations. As it does, the Pointe-au-Chien Indian Tribe and other Indigenous people are fighting to protect what’s left and to adapt to their changing environment. That includes a painstaking effort to build makeshift reefs that slow erosion and sturdier homes and buildings to better withstand storms.

“We want to be able to make it so that people can stay here for as long as possible, for as long as they want to stay,” said Matherne, who as the tribe’s director of daily operations helped coordinate its response to the erosion threat.

They hope to avoid the fate of the Jean Charles Choctaw Nation, a nearby tribe that was forced to move three years ago about 40 miles (64 kilometers) north from the encroaching Gulf of Mexico. Isle de Jean Charles — their island home southwest of New Orleans — has lost 98% of its land.

What’s eating away at the Louisiana coastline

Louisiana’s coast has been steadily retreating for several reasons.

Levees along the Mississippi River have severed the natural flow of land-creating sand, silt and clay, starving wetlands of sediment they need to survive. Canals have allowed saltwater to flow into wetlands, killing freshwater vegetation that holds them together and accelerating erosion. Groundwater pumping is causing land to sink, and planet-warming emissions from burning coal, oil and gas are fueling hurricanes and accelerating sea level rise.

Since the 1930s, Louisiana has lost about 2,000 square miles (5,180 square kilometers) of land — sometimes fast, sometimes slow. A U.S. Geological Survey analysis found that when erosion was at its worst, a football field’s worth of coastal wetlands was disappearing every 34 minutes.

It’s a difficult problem to solve without being able to count on the Mississippi River to periodically drop sediment to maintain the land, said Sam Bentley, geology professor at Louisiana State University.

“That’s going to displace ecosystems, it’s going to displace communities, it’s going to isolate infrastructure that’s along the coastline,” Bentley said. “And there are going to be a lot of changes that are very hard to deal with.”

Indigenous burial and cultural sites risk eroding, and traditional ways of life — shrimping, fishing and subsistence farming — are under pressure. Without action, researchers estimate the state could lose up to 3,000 square miles (7,770 square kilometers) — an area larger than Delaware — over the next 50 years.

Slowing erosion with recycled oyster shells

Reefs built from oyster shells are one attempt to stem the erosion.

The oysters are collected from restaurants, stuffed into bags and stacked just off shore to form the reefs. The program, launched in 2014 by the Coalition to Restore Coastal Louisiana, has recycled more than 16 million pounds (7.3 million kilograms) of shells in that time. That’s enough to protect about 1.5 miles (about 2.4 kilometers) of shoreline.

Since the Pointe-au-Chien tribe had a 400-foot (123-meter) reef built in 2019 to protect a historic mound, the coalition has measured a 50% reduction in the rate of land loss where the reefs were built, said coalition spokesman James Karst.

But there are limits to what reclaimed oyster shells can do. There just aren’t enough shells for Louisiana’s estimated 7,721-mile (12,426 kilometer) coastline, said Karst, and moving them is expensive, so they have to be strategic. Many reefs they’ve built protect sites of cultural importance. They’re also limited to areas where the water is salty enough for the oyster shells to last.

Their work might seem like a tiny drop in the bucket, “but when you are losing land at the rate you are,” Karst said, “you need all the drops in the bucket you can get.”

Some of the coalition’s most recent work came about 30 miles to the southwest of the Pointe-au-Chien’s land, in a project with the Grand Caillou/Dulac Band of Biloxi-Chitimacha-Choctaw Tribe that wrapped up in November. It was built at the Louisiana Universities Marine Consortium, a location easy for the public to see and learn about oyster reefs, said Chief Devon Parfait.

Fortifying buildings from powerful storms

When Hurricane Ida hit in 2021, it made landfall in the region with maximum sustained winds of 150 mph (241 kph).

Scores of homes in and around Pointe-au-Chien were damaged or destroyed. Some families moved inland or left the area entirely, but most came back. With help from groups like the Lowlander Center, a nonprofit working with Indigenous and coastal communities facing risks such as climate threats and land loss, the tribe is rebuilding in a stronger way.

Homes are higher off the ground and fortified with hurricane straps, heavy-duty windows and doors that can take pummeling winds and waters. Electrical equipment is elevated to stay above storm surge. They’ve rebuilt or repaired 13 homes; about five new homes are planned and they’re raising money to fortify the remaining dozen or so.

“We know that doing just one home in a community doesn’t make the community safe. It’s only safe if the whole community is included in raising that level of safety,” said Kristina Peterson, director and co-founder of the Lowlander Center.

Future plans and challenges

But challenges remain. The state-recognized tribes have struggled to get federal recognition, they said, and without it, it’s hard to get grants and other help from the federal government. Instead, they rely on partnerships with organizations and institutions.

The Trump administration’s funding cuts are also making it harder for tribes to meet their goals.

The Grand Caillou/Dulac Band of Biloxi-Chitimacha-Choctaw applied for a federal grant to build a community center stocked with food, water and renewable energy in case of emergencies that’s designed to hold up during hurricanes. When cuts happened, their application was tabled.

Similarly, the Pointe-au-Chien applied for money to install solar panels on every home, but they’re not hopeful their application will get approved.

A changed landscape

Pointe-au-Chien elder Theresa Dardar said much has changed in the five decades she’s lived there. The pond behind her home has gotten bigger, and she could once identify lakes Chien and Felicity. Now it’s just one large body of water. People once hunted deer and walked through wooded areas.

What hasn’t changed is the quiet and the close ties. Everybody knows everybody. And people still fish like generations did before them.

“This is where our ancestors were, and we feel like we would be abandoning them” to leave, Dardar said. “We have sacred sites that we still visit.”

By slowing erosion and building more homes, the tribe hopes younger families will move to Pointe-au-Chien. They also know that protecting their lands from going underwater will protect regions further inland.

As Dardar put it: “We’re the buffer.”

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