Project Spotlight: Army Corps of Engineers – West Bay Sediment Diversion (MR-03)

One of the first uncontrolled sediment diversions built specifically for coastal restoration, the West Bay Sediment Diversion has built over 3,500 acres of intermediate marsh.

What is the name of the project, and where is it located? 

West Bay Sediment Diversion (MR-03) by the Army Corps of Engineers New Orleans District. 

The diversion site is located on the west bank of the Mississippi River, in Plaquemines Parish, Louisiana, 4.7 miles above Head of Passes. The project diverts Mississippi River water and sediments into West Bank.

What was the timeline for this project?

Construction started in September 2003 and was completed in November 2003.

How many acres of wetland does this project benefit/create? 

Since the project’s construction completion in November of 2003, approximately 3,500 acres of intermediate marsh have been gained in the project area through direct material placement and naturally occurring sedimentation. 

What is most important/impactful about this project? 

This project demonstrates the unique ability to restore land created by a diversion of the Mississippi River. Constructed in only three months through dredging, this project will continue to see benefits as long as the diversion remains open. 

Is there anything unique about this project you would like to bring attention to? 

The conveyance channel allows fresh water and sediment to flow from the Mississippi River to restore vegetated wetlands in an area that was shallow open water. This project relies on the constant presence and sediment trail traveling down the Mississippi. It is a use of Mississippi River that naturally rebuilds the Louisiana marsh. 

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Against The Flow – 64 Parishes

West Bay Diversion Project Fact Sheet

Stress Part II: Flooding and Hypoxia

Wetland inhabitants must also deal with flooding stress. All parts of a plant must have oxygen, which causes problems when a plant is rooted in hypoxic soils and it is flooded. Gases diffuse about 10,000 times more slowly through water than through air, and wetland soils are often inundated and hypoxic. This poses an issue for supplying roots with enough oxygen since they don’t have any around them. Some root systems will have adventitious roots, which means they extend above the surface of the water or soil to allow gas exchange with the atmosphere.[1] Red mangroves have prop roots, black mangroves have pneumatophores, and both supply oxygen directly to the root system rather than relying on transport all the way from the leaves to the roots.[2]

Hypoxia can be caused by eutrophication and decomposition. Hypoxia and anoxia are dangerous to most plants and animals because most cannot live only with anaerobic (without oxygen) respiration. Bacteria can sometimes live in anoxic conditions by using different electron receptors that are more plentiful in wetland soils like sulfates. Plants can sometimes cope with hypoxia thanks to adaptations like aerenchyma development in their roots. Aerenchymous tissues are much more porous to allow gases to diffuse up to 30 times more easily through a plant! In animals, lungs can allow some fish, mammals, and aquatic gastropods (snails) to live in hypoxic waters, but many fish have gills that are not adapted to hypoxia. The Gulf of Mexico along Louisiana’s coast boasts one of the largest hypoxic zones in the world with a peak area of over 8,500 square miles in 2017, where many commercial fisheries have seen a large decline in fish catch. [3]

Photo from NOAA, Dead Zone 2017

Works Cited:

[1] Gilman, Sharon. “Plant Adaptations.” ci.coastal.edu/~sgilman/778Plants.htm.

[2] “Adaptations.” Adaptations :: Florida Museum of Natural History, http://www.floridamuseum.ufl.edu/southflorida/habitats/mangroves/adaptations/.

[3] “Gulf of Mexico ‘Dead Zone’ Is the Largest Ever Measured.” Gulf of Mexico ‘Dead Zone’ Is the Largest Ever Measured | National Oceanic and Atmospheric Administration, web.archive.org/web/20170802173757/http:/www.noaa.gov/media-release/gulf-of-mexico-dead-zone-is-largest-ever-measured.

Featured image is of Rhizophora mangle (red mangrove) from Flickr by barloventomagico

Salinity Stress and Tolerance

Living in any habitat comes with hurdles that make it harder for plants and animals to thrive. We call these hurdles “stress”. Coastal wetlands demonstrate several kinds of stresses to both plants and animals. Through many years of evolution, plants and animals have adapted to living with these stresses, also called being “stress tolerant”. Adaptations can be in physical structure changes or on the smaller scale (cellular). Some stresses that come with living in coastal wetlands include salinity (the amount of salt or ions in the water), inundation (flooding at least above the ground, sometimes even higher than the whole plant), and hypoxia (low dissolved oxygen in the water). [1]

Salt water intrusion has been increased by dredging navigation channels among other impacts. Saltwater intrusion makes fresh bodies of water more saline than they usually are. The problem with this is that the plants that live in such places are adapted to live in fresh water and generally cannot deal with increases in salinity more than 1 or 2 parts per thousand (ppt). For reference, the Gulf of Mexico’s average salinity is approximately 36ppt. Some plants, though, can live in full-strength sea water. For example, the black mangrove (Avicennia germinans) has several adaptations that let it keep its cells safe from high salinity. Like smooth cordgrass (Spartina alterniflora), black mangroves excrete salt onto their leaves to get it out of their systems.[2] Some fish have similar adaptations in their gills that allow them to keep their internal salt concentrations at safe levels.

Salt Crystals accumulate on A. germinans leaves (Photo by Ulf Mehlig, found on Wikimedia Commons)

 

Works Cited:

[1] Bradford, Nick. “Stressed Wetlands.” NEEF, 10 May 2016, http://www.neefusa.org/nature/land/stressed-wetlands.

[2] Gilman, Sharon. “Plant Adaptations.” ci.coastal.edu/~sgilman/778Plants.htm.

Featured image is of A. germinans from Wikimedia commons, courtesy of Judy Gallagher

Audubon Zoo – Earth Fest

Environmental awareness is an important factor in protecting the earth, and the Audubon Institute understands that. With the help of Entergy, the Audubon Zoo has hosted Earth Fest for over twenty years to date, celebrating conservation and environment-friendly practices.

This past Saturday, March 24, CWPPRA was one of many organizations to be represented at Earth Fest along with Wetland Watchers, EnergySmart, Sea Grant, and many more. Each of these organizations brought educational activities to be enjoyed by children and adults alike, such as demonstrations of energy-saving appliances, composting, and beekeeping strategies. Participants could paint with produce from a local farmer’s market, learn about the similarities in bone structures between humans and manatees, and get their faces painted. When they were not busy visiting the zoo enclosures or talking to organizations, guests could enjoy a number of local food vendors or live performers at the pavilion, including Grammy-winning Lost Bayou Ramblers from south Louisiana.

CWPPRA Public Outreach spent the day handing out informational booklets about restoration projects, posters from the Protect Our Coast series, and activity books, as well as playing our popular “Wetland Jeopardy” game with any and all who were interested. Many eager and interested visitors participated in the Earth Fest Earth Quest, a game that led them to ask questions to appropriate organizations in exchange for a stamp. 10 stamps earned them a prize of a young plant to take home and care for. Earth Fest had a wide range of attractions that hopefully inspired all visitors to be more conscious of environmental issues and to help in the efforts to live for a healthier tomorrow.

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New Orleans Landbridge Shoreline Stabilization & Marsh Creation (PO-169)

Since 1956, approximately 110 acres of marsh has been lost along
the east shore of Lake Pontchartrain between Hospital Road and
the Greens Ditch. One of the greatest influences of marsh loss in
the area can be attributed to tropical storm impacts. Wetland losses
were accelerated by winds and storm surge caused by Hurricane
Katrina, which converted approximately 70 acres of interior marsh
to open water. Stabilizing the shoreline and protecting the
remaining marsh would protect natural coastal resources dependent
on this important estuarine lake, communities that thrive on those
resources, the Fort Pike State Historical Site, and infrastructure
including U.S. Highway 90. USGS land change analysis
determined a loss rate of -0.35% per year for the 1984 -2011
period of analysis. Subsidence in this unit is relatively low and is
estimated at 0-1foot/century (Coast 2050).

Lake Pontchartrain supports a large number of wintering
waterfowl. Various gulls, terns, herons, egrets, and rails can be
found using habitats associated with Lake Pontchartrain, which has
been designated as an Important Bird Area by the American Bird
Conservancy. Restoring these marshes will protect the Orleans
Landbridge and will help to protect fish and wildlife trust resources
dependent on these marsh habitats, particularly at-risk species and
species of conservation concern such as the black rail, reddish
egret, brown pelican, mottled duck, seaside sparrow, king rail, and
the Louisiana eyed silkmoth.

Borrow material will be dredged from areas within Lakes St.
Catherine and Pontchartrain to create 169 acres and nourish 102
acres of brackish marsh. Containment dikes will be constructed
around four marsh creation areas to retain sediment during
pumping. The lake shorelines will be enhanced with an earthen
berm to add additional protection from wind induced wave fetch.
Containment dikes that are not functioning as shoreline
enhancement will be degraded and/or gapped. Vegetative plantings are
proposed including five rows along the crown and two rows
along the front slope of the shoreline protection berm, as well as
within the marsh platform area.

The project is located in Region 1, Pontchartrain Basin,
Orleans Parish, flanking U.S. Highway 90 along the east shore of
Lake Pontchartrain and areas surrounding Lake St. Catherine.

This project was approved for Phase I Engineering and Design in
January 2015.

This project is on Priority Project List (PPL) 24.

The New Orleans Landbridge Shoreline Stabilization & Marsh Creation sponsors include:

• Federal Sponsor: U.S. Fish and Wildlife Service
• Local Sponsor: Coastal Protection and Restoration Authority

 

 

Bayou Dupont Sediment Delivery – Marsh Creation and Terracing

Wetlands in the Barataria Basin were historically nourished
by the fresh water, sediment and nutrients delivered by
the Mississippi River and its many distributary channels.
These sediment and nutrient inputs ceased following the
creation of levees along the lower river for flood control and
navigation. In addition, the construction of numerous oil and
gas canals along with subsurface oil and gas withdrawal has
exacerbated wetland loss in the area. From 1932 to 1990, the
Barataria Basin lost over 245,000 acres of marsh. From 1978
to 1990, the area experienced the highest rate of wetland loss
in coastal Louisiana.

The primary goal of this project is to create and nourish
approximately 144 acres of emergent intermediate marsh
using sediment from the Mississippi River, and constructing
9,679 linear feet of terraces. The proposed project includes
dredging sediment from the Mississippi River for marsh
creation by pumping the sediment via pipeline into an area of
open water and broken marsh. The proximity of the project
to the Mississippi River provides a prime opportunity to
utilize this renewable river sediment resource. The strategy
includes utilizing the access route and infrastructure
previously put into place for the BA-39 project. This project
will complement existing restoration projects in the area.

CWPPRA Region 2, Barataria Basin, Jefferson and
Plaquemines Parishes. The general project area is about 10
miles south of Belle Chasse, LA and is west of LA Hwy
23 and north of the Myrtle Grove Marina. The project
is immediately adjacent to the completed CWPPRA
Mississippi River Sediment Delivery System – Bayou
Dupont (BA-39) project.

The project was approved for engineering and design at the
January 24, 2013 Task Force meeting. The E&D was
completed in the fall of 2014 and sponsors requested phase
2 funding at the January 22, 2015 Task Force meeting,
however, there was insufficient money available to fund
the entire project. In order to take advantage of the existing
mobilization of the Long Distance Sediment Pipeline
(LDSP) Project, the sponsors proposed to reduce the scope
of the project to fit within the available CWPPRA funding.
The Task Force approved the reduced scope Phase 2 funding
request at the May 14, 2015, Task Force meeting. The asbuilt
project features include 144 acres of marsh creation and
9,679 linear feet of terracing.

In addition, CPRA increased the marsh creation feature of
the project by utilizing contingency funding left over from
BA-43, thereby increasing the total marsh creation in the
area to an estimated 296 acres. Construction started in April
2016, and marsh creation was completed in November
2016. Terracing was completed in June 2017, and vegetative
plantings for the terraces are scheduled for the spring of
2018.

This project is on Priority Project List (PPL) 22.

The Bayou Dupont Sediment Delivery – Marsh Creation and Terracing sponsors include:

• Federal Sponsor: U.S. Environmental Protection Agency 
• Local Sponsor: Coastal Protection and Restoration Authority

 

America Recycles Day

     Today we celebrate America Recycles Day: a national initiative of Keep America Beautiful. Recycling offers numerous benefits to both our environment and human health. Recycling is one of the best actions you can take to protect natural resources. Plastics being discarded in animal habitats continue to pose a serious threat to the health of wildlife that occupies the area. Many animals die each year from ingestion of these hazardous materials, and researchers in Ireland found that plastic bags littering wetlands could smother wildlife and algae underneath [Green et al., Environ. Sci. Tech., 2015, 49 (9), pp. 5380-5389]. Along with providing a healthier habitat for animals to live, recycling beautifies the area humans utilize for recreational purposes. You can help save our wetlands and other natural habitats by picking up litter and disposing of the unwanted materials in the appropriate recycling bins or at recycling centers.

     Visit the America Recycles Day website to find valuable information on what materials can be recycled, where they can be recycled, and how they can be recycled. The recycling locator is a useful tool the website provides for finding locations to recycle in your community. While you’re visiting the America Recycle Day website, you can also take the #BeRecycled Pledge to learn, act and share with others the power of recycling.

Wetland Wonders at Ocean Commotion

Can you figure out the mystery coastal item based on the following clues? It contains a bivalve that a) makes pearls, b) is a filter feeder, and c) we eat here in Louisiana.

Over 1600 elementary and middle school students had the chance to read those clues at LSU Sea Grant’s Ocean Commotion on October 24 in Baton Rouge. Students, teachers, and chaperones then reached their hands into a box and tried to identify the item (oyster shell) they were holding. Other mystery items included a nutria pelt, cypress knees, an apple snail shell, and a magnolia seed pod- all from plants and animals that call Louisiana’s coastal wetlands home.

2017 marks the 20th Anniversary of Ocean Commotion, an annual event meant to give students the chance to get up close and personal with coastal and sea life and the challenges facing those environments. This year 70 exhibitors taught students about topics as diverse as boating safety, mosquito control, and microplastics. CWPPRA outreach staff talked with students about the diversity of species found in Louisiana’s wetlands and the challenges of invasive species, giving students an opportunity to think about how different species impact ecosystems in different ways.

 

Shell Beach South Marsh Creation

The marsh boundary separating Lake Borgne and the MRGO
has undergone both interior and shoreline wetland losses due
to subsidence, impacts related to construction and use of the
MRGO (i.e., deep draft vessel traffic), and wind-driven
waves. Although much of the project area is protected from
edge erosion by shoreline protection measures, and since
2009, the MRGO has been deauthorized for deep draft
navigation and maintenance, interior wetland loss due to
subsidence continues to cause marsh fragmentation and pond
enlargement. Wetland loss rates in the project area are
estimated to be -0.60 percent a year based on USGS
analysis.

The proposed project will create and nourish 634 acres of
marsh using dredged sediment from Lake Borgne. Existing
high shorelines along Lake Borgne, remnants of previous
containment dikes and marsh edge, would be used for
containment to the extent practical. Constructed containment
dikes would be breached/gapped as needed to provide tidal
exchange after fill materials settle and consolidate. The
project would create 346 acres of marsh and nourish at least
288 acres of existing fragmented marsh. A target fill
elevation of +1.2 feet is envisioned to enhance longevity of
this land form. Additionally, 187 acres of vegetative planting
will occur within the newly created areas. Due to the
presence of existing banklines, dredged slurry overflow
could potentially be discharged immediately adjacent to the
project polygons, resulting in nourishment of additional areas.

This project is located in Region 1, Pontchartrain Basin, South Lake Borgne Mapping
Unit, St. Bernard Parish, north bank of the Mississippi River
Gulf Outlet (MRGO) in the vicinity of Shell Beach.

This project is on Project Priority List (PPL) 24.

The Shell Beach South Marsh Creation project sponsors include:

• Federal sponsor: U.S. Army Corps of Engineers and U.S. Environmental Protection Agency
• Local sponsor: Coastal Protection and Restoration Authority

Keep up with this project and other CWPPRA projects on the project page.

Coastwide Vegetative Planting

The coastal restoration community has long recognized the benefits of vegetative plantings in restoration. Many marsh creation and most terracing projects require plantings to insure success. Coastal shoreline plantings have also proven to be very effective and some have demonstrated the ability to not only stop shoreline erosion but to facilitate accretion, the process of increasing sediments. Recent hurricane events have exposed a need to have a mechanism in place where large-scale planting efforts can be deployed in a timely manner to specifically targeted areas of need, anywhere along the coast. Although the CWPPRA program can fund specific large-scale planting projects, the normal program cycle for individual projects can delay needed restoration plantings for a number of years.

The goals of this project are to facilitate a consistent and responsive planting effort in coastal Louisiana that is flexible enough to routinely plant on a large scale and be able to rapidly respond to critical areas of need following storm or other damaging events. This project set up an advisory panel consisting of representatives from various state and federal agencies who would assist in the selection of projects for funding. The project also set up a mechanism by which project nominations would be submitted for consideration. The equivalent of 90 acres of interior marsh and 40,000 linear feet of coastal shoreline will be planted per year over a 10 year period to effectively create/protect a total of 779 net acres of marsh over the 20-year project life.

The project features are located in the coastal zone of Louisiana.

This project is on Priority Project List (PPL) 20.

The Coastwide Vegetative Planting project sponsors include:

• Federal Sponsor: Natural Resources Conservation Service
• Local Sponsor: Coastal Protection and Restoration Authority

Keep up with this project and other CWPPRA projects on the project page.