Louisiana's coastline have been lost to see.

Tribal lands in the state 's# southeast are among the most af As our New Orleans communities# correspondent Roby Chavez reports,## one volunteer-led effort is gaining attention# in the fight against coastal erosion with## an unlikely tool, recycled oyster shells.

ROBY CHAVEZ: A boatride through the marshes## of Southeastern Louisiana is a painful reminder# of the state's quickly disappearing coastline.

It's a swathe of land that includes important# cultural sites.

Trees anchor tribal mounds,## some older than Stonehenge.

By some estimates,# the state is losing at least two mounds per year.

Theresa Dardar is a member of the Pointe-au-Chien# Indian Tribe.

For years, she felt helpless## watching parts of the tribe's sacred land# fall in the water.

To help protect the land## from rapid erosion, the tribe partnered with the# nonprofit coalition to restore coastal Louisiana## and used recycled oyster shells from local# restaurants to build artificial reefs.

THERESA DARDAR, Pointe-au-Chien Indian# Tribe: They're helping us to try to## save what we want to save.

It makes you# feel s that they're not just here to see what's# happening.

They're here because they care.

ROBY CHAVEZ: The coalition used nearly 400 tons# of shells to create oyster reefs that now cover## 800 feet of coastline near the tribal mounds.

So# far, their project is working.

The coalition's## reefs have withstood Hurricane Ida in 2021 and# slowed shoreline erosion by as much as 50 percent.

JAMES KARST, Coalition to Restore Coastal# Louisiana: We take a product that used to## get sent to the landfill, but is very# an d we put it back into the# water, where it belongs.

ROBY CHAVEZ: James Karst works with the# coalit are designed to mimic nature, providing# coastal protection for years to come.

Once these reefs are in place, tell us# what happens to them just organically.

JAMES KARST: Life begins to grow on# them.

Baby oysters are attracted to## the old oyster shells, and they attach to them,## and they begin to grow.

And that is why# they are considered to b To me, it is sort of the ultimate sustainable# seafood.

It's really a win-win-win,## because oysters also filter the water.

They can# help to minimize storm surge during hurricanes## and tropical storms, and they slow the# rate of erosion by a significant amount.

ROBY CHAVEZ: In one of the largest# shell recycling programs in the nation,## the coalition has so far built five oyster reefs# protecting 8,000 feet of disappeari In all, 13 million pounds of shells have# been recycled.

Louisiana is the nation's## top oyster producer, and nearly# 50 restaurants now participate in## the recycling program that keeps# their oysters out of landfills.

James Clesi is the co-owner of# Clesi's Seafood Restaurant.

He## says signing up for the program was a no-brainer.

JAMES CLESI, Co-Owner, Clesi's Seafood# Restaurant: We go throug oysters.

I want to say thousands and# thousands cool to know that they're going right back# to the water to help the oyster lifestyle.

It gets really easy just to order the# oysters, cook them, shuck them, serve them,## and not really know where they came# from.

And it gave us an opportunity## for us to learn the whole life cycle# of the oyster, how important it is## to the Louisiana coastline and the way of# life for everybody that lives down there.

ROBY CHAVEZ: Back on the water,# Theresa Dardar and her husband,## Donald, know the oyster reefs won't be# a cure-all.

They're al backfill oil and gas exploration# canals that cut into the marsh.

But, for now, it no longer feels# like they are alone in the fight.

For the "PBS NewsHour" in# New Orleans, I'm Roby Chavez.