Hydrologic Restoration and Vegetative Planting (BA-34-2)


The Lac des Allemands River Basin Initiative identified the following specific problems within the Lac des Allemands Watershed: drainage impairments; water quality impairments; loss of marsh; and decline of cypress forest. Many years of study by Louisiana State University researchers in these swamps have demonstrated that, because of impoundment, subsidence, and inadequate accretion of sediments and organic matter, some areas are already highly stressed and converting to open water, floating aquatic plants, and fresh marsh. Also, the Coast 2050 report suggests that other areas of the swamps throughout the basin will likely convert to open water or floating marsh by the year 2050. These problems are caused by the loss of river water along with the associated sediment and nutrients necessary for swamp health. The loss of river water can be attributed to the leveeing of the Mississippi River. Impoundment caused by roads, drainage canals, and spoil banks is also a major cause of degradation of these swamps.
Restoration Strategy:

The original proposed restoration strategy included installing two small siphons (averaging 400 cubic feet per second) to divert water from the Mississippi River; gapping spoil banks on Bayou Chevreuil; gapping spoil banks along the borrow beside Louisiana Highway 20; installing culverts under Louisiana Highway 20; improving drainage in impounded swamps; and planting cypress and tupelo seedlings in highly degraded swamp areas.

The proposed diversion from the Mississippi River was to bring fresh water, fine-grained sediments, and nutrients into the upper des Allemands swamps, which would have helped maintain swamp elevation, improve swamp water quality, and increase productivity and regrowth of young trees as older trees die. However, after hydrologic modeling and more detailed engineering/design and cost estimation, it was determined that the siphon would cost far more than originally anticipated. For that reason, the CWPPRA Task Force approved the project sponsors’ request to re-scope the project to eliminate the siphon feature, and to focus on the remaining project features.


Location: The project is located West of Lac des Allemands in St. James Parish, Louisiana, south of the town of South Vacherie, bordered on the south by Bayou Chevreuil, and on the east by LA Highway 20.

Progress to Date: The Louisiana Coastal Wetlands Conservation and Restoration Task Force approved Phase 1 funding in January 2001. In June 2013, the Task Force approved a request to change the scope of the project to eliminate a siphon feature and focus on the remaining original hydrologic restoration and vegetative planting project features. The Louisiana Coastal Protection and Restoration Authority performed the engineering and design services. Design was completed in October 2015 and Phase 2 funds for construction was approved by the Task Force in January 2016. Construction activities for excavation and placement began in October 2017 and ended on December 20, 2017, vegetative plantings occurred in late January, and officially completed on February 2, 2018.

The three (3) principal project features included:

1. Eight (8), 400-foot-long, strategically designed gaps were cut in the northern Bayou Chevreuil spoil bank to reverse the effects of impoundment;

2. Sixteen (16) spoil placement areas were created on each side of the channel banks; (1 placement area on both sides of each gap) to beneficially use the dredged material on site;

3. Seven hundred (700) Bald Cypress and one hundred (100) Water Tupelo saplings were planted in the constructed spoil placement areas to start swamp regeneration and swamp productivity.

This project enhanced 2,395 acres of swamp habitat that would have continued to degrade without the project.

This project is on Priority Project List (PPL) 10.

The sponsors include:

Federal Sponsor: U.S. Environmental Protection Agency

Local Sponsor: Coastal Protection and Restoration Authority (CPRA)




Classifying Wetlands Part 2

Last week’s Wetland Wednesday mentioned 3 main criteria as part of identifying a wetland (wetland hydrology, hydrophytic vegetation, and hydric soils). – Today we’ll look at how plants and soils help scientists delineate wetlands.

In the field, scientists identify and sample soils and plants as part of wetland delineation. The LSU AgCenter groups plant species based on where the plant is naturally found as seen in the table below.

indicator_2Wetland plants have adapted to flooded soils. “Obligate” plants can tolerate water at high levels or when soil saturation is a normal condition to that area. Examples of these plants include the bald cypress (Taxodium distichum), or cattail (Typha latifolia) [3].

In contrast, plants that cannot handle flooded conditions for an extended period would naturally be in the “upland” area of land (i.e. winged sumac (Rhus copallina), eastern redbud (Cercis canadensis), or panic grass (Dichanthelium sp.) [3].

People delineating wetlands focus on a project area according to aerial and soil maps along with aerial photographs [1]. Delineators then take soil samples and determine characteristics seen in hydric soils which relate to cycles of flooding and drying. – Examples of those include oxidized soils, hydrogen sulfide (rotten egg smell) and organic bodies found on plant roots. Finally, the plant and soil types are compared, tested, then matched to determine wetland boundaries for mapping and policy purposes [1].

Wetland delineation is a tool for protecting and documenting these important landscapes which contribute to a healthy and functional environment. It is important to note that wetland delineation requires much more than just plant and soil identification. CWPPRA utilizes sound science, engineering, mapping, and geo-technical surveys in the process of planning, approving, constructing, and maintaining coastal Louisiana wetland restoration projects.


[1] Bedhun, Rebecca. 2018. “Watch and Lean Now: How To Do A Wetland Delineation”. Shoret Elliot Hendrickson Inc. Available: http://www.sehinc.com/news/watch-and-learn-now-how-do-wetland-delineation [September 9, 2018]

[2] Jon Kusler. “Common Questions: Wetland Definition, Delineation, and Mapping”. Association of State Wetland Managers, Inc. Available: https://www.aswm.org/pdf_lib/14_mapping_6_26_06.pdf [September 9, 2018]

[3] LSU Ag Center. 2018. Louisiana Plant Identification: Plant List. Available: http://www.rnr.lsu.edu/plantid/listcommon.htm [September 10, 2018]



Classifying Wetlands Part 1

When we think of wetlands, our mind may paint a picture of a swampy area with open water, and maybe a heron or alligator. Despite common perception, not all wetlands are the same. — These watery features come in all shapes, sizes, and locations along with a unique system of processes and purpose.

Wetlands are diverse and the difference between dry and wet environment lies along a gradient. Therfore, there cannot be one perfect definition to represent what a wetland is. Scientists have developed criteria to identify wetlands and aid in assessment, inventory, and management [1].

Figure 1. An example used by scientists to start the process for wetland delineation.

Criteria Definition
Wetland hydrology the gradient or degree of flooding or soil saturation across a landscape [2].
Hydrophytic vegetation plants adapted to grow in water or in a soil that is occasionally oxygen deficient due to saturation by water [2].
Hydric soils soils that are sufficiently wet in the upper root zone  and may develop anaerobic (oxygen lacking) conditions during the length of at least 1-2 growing seasons [2].

As seen below in Figure 2 and 3; some wetlands are flooded year-round while other  water levels fluctuate. The wetland hydrology differs depending on location and the geography of the landscape.

Figure 2: A simplified example of a wetland water gradient dependent on elevation and tidal ranges.

better_gradient pic.png

Figure 3.

basic_gradientYou may not live close to a coastal marsh, but many water sources eventually connect to a wetland on the coast, making the streams, lakes, and swamps in your backyard an important link to the larger watershed. That’s why it’s important to support, respect, and appreciate the water systems and land of everyday life. CWPPRA projects restore and protect these systems to support the livelihood and cultures of Louisiana and to protect the land we value so dearly.

In next week’s edition of Wetland Wednesday, we’ll look at how scientist use vegetation and soils to classify wetlands!


[1] Fish and Wildlife Service. Classification of Wetlands and Deepwater Habitats of the United States. Available: https://www.fws.gov/wetlands/documents/Classification-of-Wetlands-and-Deepwater-Habitats-of-the-United-States-2013.pdf [August 27, 2018].
[2] Natural Resources Conservation Service. Hydric Soils Overview. Available: https://www.nrcs.usda.gov/wps/portal/nrcs/detail/soils/use/hydric/?cid=nrcs142p2_053985 [August 27, 2018].


This week marks 13 years since Hurricane Katrina, an event some citizens of Louisiana are still recovering from. We may have all heard the name, but do we know what a hurricane is, how wetlands are affected, and how coastal landforms can decrease hurricane impacts?

“Hurricanes” are low-pressure tropical storm systems that differ from other storms in severity as well as location. A hurricane is a storm with winds above 64mph accompanied by heavy rain that originates in either the NE Pacific or the N Atlantic Ocean (the oceans that touch the USA). Due to a phenomenon called the Coriolis Effect, hurricanes rotate counter-clockwise, whereas a southern hemisphere storm would rotate clockwise. Hurricanes develop a characteristic “eye of the storm” in the center, which is an area of low pressure and low wind. Just outside of the eye is the most severe weather, the eyewall, with winds reaching up to 210mph in the strongest storms! Hurricane “category” ratings are as follows:

  • Category 1: 74-93mph
  • Category 2: 96-109mph
  • Category 3: 110-129mph
  • Category 4: 130-157mph
  • Category 5: >158mph

Hurricanes develop over areas with warmer waters, typically nearer the equator, and move away from the equator. [1] Coastal Louisiana is hit by hurricanes on an increasingly regular basis, and those hurricanes all develop in the North Atlantic Ocean in late summer and fall. Our “Hurricane Season” occurs from June through November each year. [2] Several aspects of hurricanes pose major threats to our wetlands statewide. High winds can topple trees, rip up shrubs and grasses, and move sediments around. High rainfall can cause flooding in areas that are not well-adapted to high-water conditions. Storm surge can push saline seawater into brackish and freshwater systems. Hurricanes cause massive disturbance in coastal wetlands, but wetlands are a crucial barrier that protects major cities from taking as much damage. CWPPRA works to combat land loss and protect the future of coastal Louisiana.

Some CWPPRA projects restore barrier islands, which are natural defenses that develop in the Deltaic Cycle. Barrier islands lessen storm surge during hurricanes, bearing the brunt of the waves. Sadly, they cannot provide perfect protection because they are degrading, but they are not the last line of defense. We still have coastal marshes that are great at storing water and acting like a speed bump to storm surge. It is estimated that each mile of coastal marsh decreases storm surge by about a foot. Unfortunately, many coastal marshes are decaying into open water and are no longer protective barriers. CWPPRA will continue to restore wetlands and nourish barrier islands to #ProtectOurCoast!


[1] https://en.wikipedia.org/wiki/Tropical_cyclone

[2] https://www.ready.gov/hurricanes

Featured image from [1]

Sugar Cane

The natural flooding of the Mississippi River has produced fertile wetland soils which farmers in Louisiana use to grow sugar cane. Sugar cane was introduced in the plantation region around New Orleans in the 1750s and succeeded due to the slave labor required to cultivate the crop. [1] Commercial farming hit its stride with the introduction of new technology for granulating sugar in 1795  at Étienne de Boré’s plantation. Ever since , Louisiana’s sugar cane industry has flourished and remained, to this day, one of Louisiana’s main agricultural products.

At least 25,000 Louisiana residents across 23 parishes grow, harvest, or process sugar cane from around 400,000 acres of farmland that are set in our fertile wetlands. Multiple effect evaporators, invented in 1834 by a Creole chemical engineer named Norbert Rillieux, a free man of color, are still used today. [2] New innovations in crop protection, hardiness of varieties, and processing techniques continue to rake in $645 million from exports alone, constituting 16 percent of total national sugar production. [3] Interspersed between sugar cane fields, one can find dual rice-crawfish fields as well as soybeans, cotton, and corn. Sweet potatoes and juicy Louisiana strawberries are among the state’s staple crops as well.

Even with new technologies and innovations, fertile soils are still one of the largest contributing factors to the success of agriculture in our wetland state. Land loss threatens to ruin the livelihood of Louisiana farmers. Salt water intrusion continues to penetrate our interior agricultural land as our coastal marshes vanish. More about salt water intrusion can be found in our post about the topic. [LINK] Restoring natural hydrology and preventing saltwater intrusion from harming our fertile wetland soils is imperative for Louisiana farmers. Protecting our coast has long-reaching benefits to our vital agricultural industry, our citizens, and our state, and CWPPRA is working alongside other groups to restore our natural coastline for a sustainable future.

[1] http://www.assct.org/louisiana/progress.pdf

[2] https://www.lsuagcenter.com/profiles/lbenedict/articles/page1503347392487

[3] https://www.lsuagcenter.com/portals/communications/publications/agmag/archive/2008/spring/sugar-processing-in-louisiana

Featured Image from https://www.trover.com/d/1zHAz-new-iberia-louisiana

Pecan Island Terracing (ME-14)

wordpress fact sheet banner ME-14-01

In the mid-1950s continuous dikes were constructed and water was pumped off the marsh, transforming it into dry pastureland. As a result of oxidation, the soil elevation has subsided 1 to 2 feet. Deterioration and loss of the perimeter levees in recent years has converted the entire area into a shallow, open water lake with a few small marsh islands resulting in a net loss of fisheries habitat.

The restoration project will reduce marsh erosion by creating emergent terraces designed to minimize wave fetch across open water and, at the same time, creating linear marsh features. Future marsh loss will be prevented and brackish marsh will be restored. Construction of the earthen terraces in shallow water areas will also convert areas of open water back to vegetated marsh creating more habitat for fish and shellfish. The project calls for constructing adjacent terrace cells in a staggered gap formation, each bordered by terraces made from dredged material. Terraces will be built and planted with smooth cordgrass (Spartina alterniflora), and California bulrush (Scirpus californicus). Plantings may also occur on the north side of the terracing area.map.jpg


This project is located in southeastern Vermilion Parish, Louisiana, approximately 5 miles north of the Gulf of Mexico just south of Pecan Island and Louisiana Highway 82.

The project construction was completed in August 2003, initially creating over 122 acres of emergent marsh. The monitoring plan was finalized in November 2001 and data collection has been ongoing since that time.

This project is on Priority Project List 7.

The Federal Sponsor is NOAA

The Local Sponsor is CPRA

Biological Diversity

Today, CWPPRA celebrates the International Day of Biological Diversity and the variety of species Louisiana’s coastal wetlands! Louisiana’s wetlands boast a wide array of ecosystems, including upland hardwood forests, forested wetlands known as swamps, salt and freshwater marshes, and barrier islands, that allow for species to thrive and diversify into specialized niches.  Throughout the United States, we all benefit from Louisiana’s wetland biodiversity, especially the abundance of fresh fish and seafood species.

The fact that we have so many desirable species in our coastal waters is a huge benefit to the state’s economy, and the seafood industry provides many Louisiana residents with job opportunities. Louisiana fisheries contribute about $2.4 billion to our economy each year. About $1.3 billion of that sum is directly from the shrimp catch. Recreational fishing is a popular pastime in this area as well, which is supported by wetland habitats. Our rich diversity allows for people to choose from a variety of prey. Many fishermen diversify their catches so that if one species limit is reached or season is passed, they can collect other species. Limits are put in place to keep populations stable, which maintains ecological interactions and the vibrant ecosystems we are so proud of. For more information about limits and fishing licenses, visit the Louisiana Department of Wildlife and Fisheries.

From the flavor of the meat, to the number of bones, each species has different value to fishermen and consumers. Differences in physiology and morphology between fish in our coastal waters are as abundant due to our biodiversity. We have bony fish and cartilaginous fish, plant- and meat-eaters, fresh and saltwater species, fish with or without spines, and the list goes on and on. These different types of fish coexist because our coast is so productive. Normally, ecosystems evolve predictably as populations move and change size and they are resilient to an extent. However, large-scale disturbances that interrupt the natural interactions and processes—like the sudden proliferation of an invasive species, man-made disasters like the Deepwater Horizon oil spill, and large weather events—can cause major problems for our native species.

Diversity is an important factor in a healthy ecosystem and Louisiana is fortunate to have our abundant and protective coastal zone, but we are losing these important habitats to land loss. Land loss affects the diversity of our species and the industries that rely on these species. CWPPRA is dedicated to make sure our projects have a positive impact on our native species of plants and animals before construction begins. CWPPRA strives to protect the natural splendor that makes Louisiana the “Sportsman’s Paradise” for generations to come.


Featured Image from https://beckyeldredge.com/shrimp-boats

Endangered Species

Vanishing wetlands pose a threat to species who reside in these unique habitats for all or part of their life cycle. Population decline can be caused by a variety of threats, including invasive species competition, habitat loss, and overharvesting or over-predation. There are species who rely heavily on constant or predictable conditions in specific parts of the year such as seasonal rainfall, temperature cycles, and sometimes other species who migrate for part of the year. Populations subjected to too much stress for an extended period often experience population decline as well. In some cases, those species become threatened, endangered, or even extinct.

CWPPRA and U.S. Fish and Wildlife Service will celebrate and observe Endangered Species Day on May 17th, 2019, to celebrate and highlight the species and habitat protection efforts throughout the coast. Louisiana is home to 11 endangered species, including three species of bivalve mollusks, three species of sea turtle, two species of birds, two plants, and one fish. Of these, every single one is reliant on wetlands. All three bivalves (fat pocketbook, pink mucket, and tan riffleshell) are freshwater filter feeders who live in flowing water. They clean pollutants from the water before it reaches our coastline, improving water quality for our coastal residents. Sea turtles are among the most popular sea creatures and they rely on our coast for their nesting grounds. Leatherback (largest, deepest-diving, and most migratory), hawksbill (thickest scutes/shells), and Kemp’s ridley (smallest and rarest) feed on different creatures, but they seem to all agree on jellyfish. The two bird species on the list are the interior least tern and the red-cockaded woodpecker. Terns are fishing birds that enjoy the banks of the Mississippi River, whereas the woodpeckers utilize the upland hardwood forest ecosystems of northern Louisiana. The two plants are American chaffseed and Louisiana quillwort. Chaffseed is a semiparasite that relies on fire to proliferate in longleaf pine forests. Louisiana quillwort is a semiaquatic graminoid (grass-like plant that spends some time underwater). The lone fish species, the Pallid Sturgeon, is a ray-finned, bottom-feeding, freshwater fish that can live up to a century. They like the turbid waters of the Mississippi River and its distributaries.

Clearly, these 11 native species have adapted to Louisiana’s dynamic landscape and they each fill a different niche within their respective habitats, so a one-size-fits-all solution does not exist for their preservation. CWPPRA funds projects that help maintain or restore vital habitat for these species and the other species they rely on for food. If a species goes locally extinct, it can have a ripple effect that throws off pre-established balances throughout the ecosystem. Coastal protection has an extensive impact, protecting areas further upstream as well, so CWPPRA indirectly eases pressure on the inland species. Endangered species are one of many reasons our coast deserves to be restored and protected.

For more information about these species and other threatened and endangered species, visit the US Fish and Wildlife Service’s website: https://www.fws.gov/endangered/.

The featured image is from https://www.nature.org/en-us/explore/animals-we-protect/leatherback-sea-turtle/

Native Tribes of the Coast

Numerous Native American tribes call coastal Louisiana home. Our productive wetlands provide food, shelter, and numerous resources for tribes to successfully live in such dynamic environments. The connection these cultures have to our wetlands are threatened by coastal land loss and climate change. As seas rise and our land washes away into the Gulf of Mexico, some of these groups will have to decide to relocate. The Isle de Jean-Charles band of the Chitimacha-Biloxi-Choctaw tribe is among the first groups currently in the process of resettling away from their tribal lands. With the land loss we are experiencing along our coast, they won’t be the last.

There are four federally recognized Native American tribes in Louisiana: the Chitimacha Tribe of Louisiana, the Coushatta Tribe of Louisiana, the Jena Band of Choctaw Indians, and the Tunica-Biloxi Tribe of Louisiana. Louisiana is also known for the Atakapa, Caddo, Houma, Natchez, and Tunica tribes. [1] Many parts of Louisiana are named for the tribes that lived there or named after words in native languages, including the city of Houma, Bayou Teche, Caddo Parish, and the Atchafalaya Basin.

Food, shelter, and navigation are some of the greatest benefits to these groups living in the wetlands. Wetland soils are great for agriculture, which is crucial to grain and corn production. Hunting and fishing were and still integral to the livelihoods in many native tribes across the coast, accomplished by nets, traps, and other tools made from bone, stone, or gar scales. [2] Bayous and lakes allowed people to travel steadily and safely before the introduction of roads, which encouraged extensive trade throughout the various webs of waterways sprawling across our landscape. With such widespread fertile land, there were plenty of natural resources to sustain communities coastwide.

Just as people rely on wetlands for survival, wetlands are beginning to rely on us for survival. CWPPRA and other restoration efforts value the importance of preserving historic sites located across our coast. More protection to historic sites, current civilizations, wildlife habitat, industrial property, and our communities are all reasons to improve our coastal wetlands. Healthier and stronger wetlands mean increased protection during large-scale disturbances like hurricanes. CWPPRA has been working since 1990 to do just that because we know how valuable our wetlands are for so many groups of people, plants, and animals alike.

[1] http://www.native-languages.org/louisiana.htm

[2] http://www.chitimacha.gov/history-culture/tribal-history

Featured Image by Josh Haner with the New York Times, found at https://www.wired.com/story/how-to-save-a-town-from-rising-waters/


Lake Hermitage Marsh Creation (BA-42)

wordpress fact sheet banner BA-42-01

The project is within the West Pointe a la Hache Mapping Unit which lost 38 percent of its marsh from 1932 to 1990. By the year 2050, 28 percent of the 1990 marsh acreage is expected to be lost. That loss is expected to occur even with operation of the West Pointe a la Hache Siphon (State project BA-04). Significant marsh loss has occurred south and east of Lake Hermitage and along the eastern lake shoreline. Deterioration of the lake rim has exposed interior marshes to the wave energy of Lake Hermitage and increased tidal exchange. Based on USGS land-water data from 1985 and 2006, the project area has an annual loss rate of -1.64%.

The original project features included dredging in the Mississippi River and pumping sediments via pipeline to create 549 acres of marsh. Additionally, 6,300 feet of shoreline restoration using river material and 7,300 linear feet of terraces were included. Fortunately, a favorable bid on the construction contract allowed for project expansion and the marsh creation feature was increased to encompass a total of 795 acres.

Funding from the Louisiana Oil Spill Coordinator’s Office, the Louisiana Department of Natural Resources – Office of Coastal Management, and Deepwater Horizon Early Restoration allowed construction of an additional 215 acres of marsh. Terraces were removed from the CWPPRA project to provide an area for marsh creation with Deepwater Horizon Early Restoration funding.


The project area is located in the Barataria Basin, south and east of Lake Hermitage in Plaquemines Parish, Louisiana near the community of West Pointe a la Hache.

The Louisiana Coastal Wetlands Conservation and Restoration Task Force approved funding for engineering and design in February 2006 and approved construction funding in January 2009. Construction began in February 2012 and was completed in June 2015.

This project is on Priority Project List 15.

The Federal Sponsor is USFWS

The Local Sponsor CPRA


Oysters aren’t just delicious to eat, they are also a versatile tool to restore and protect the Louisiana coastline! Oyster reefs protect shorelines from wave energy, filter water, and improve habitat quality. Unfortunately, much of our country’s oyster production is unsustainable because of a combination of activities including over-harvesting, pollution, and habitat destruction through dredging and collection practices. As we restore oyster reefs, they will have positive environmental, economic, and cultural impacts.

In other areas of the United States, these harmful extraction methods have all but ruined the oyster industry. According to the Chesapeake Bay Foundation, their estuary has lost more than 98 percent of its oysters with major economic consequences. [1] In Louisiana, we have not experienced nearly as much damage, so we can more readily restore our reefs. Some benefits we could gain from healthier reefs, according to our partners at BTNEP, include wave energy absorption, reduction of the Gulf Dead Zone, and improved habitat for nearly 300 species of fish, crustaceans, and mollusks. By supporting oyster reefs, you support fisheries as well as resiliency. A single adult oyster can filter up to 50 gallons of water per day, removing excess nutrients and lessening the coast’s eutrophication (nutrient pollution that leads to algal blooms) and dead zones (areas of low dissolved oxygen). [2]

Aside from the numerous important ecological benefits, the price tag for oyster reef restoration is cheaper other protection techniques. According to an article in Scientific American, the adaptation strategy of raising houses onto stilts costs more than the damages it will prevent. [3] Some of the most cost-effective protection methods cited in the article included wetland restoration (nearly a 10:1 protection to cost ratio), oyster reef restoration (just over 7:1) and barrier island restoration (about 5:1). Many of these restoration and protection strategies have been utilized by CWPPRA since the 1990s.

CWPPRA projects are synergistic approaches to protecting and restoring our coast, using the best available science to implement projects in areas of most need, as well as emphasizing cooperation between projects and their managing agencies.  Sustainable innovations in oyster reef restoration is just one way in which CWPPRA achieves its goal of wetland restoration.

[1] https://www.cbf.org/about-the-bay/more-than-just-the-bay/chesapeake-wildlife/eastern-oysters/

[2] web.archive.org/web/20170802173757/http:/www.noaa.gov/media-release/gulf-of-mexico-dead-zone-is-largest-ever-measured

[3] https://www.scientificamerican.com/article/rebuilt-wetlands-can-protect-shorelines-better-than-walls/

Featured Image from https://www.nature.org/en-us/about-us/where-we-work/united-states/florida/stories-in-florida/floridas-oyster-reef-restoration-program/