The goal of building terraces is to achieve some of the same objectives as full marsh creation but over a larger area of open water, where marsh creation alone is not feasible. Terraces are long, earthen berms that are built by mechanically dredging material and piling and shaping the material to a desired height. Most terraces average around 3 feet tall, with shallow side slopes and a wide base. This size and shape optimize the amount of terrace that falls in the intertidal zone and will support wetland vegetation.
The objectives of constructing terraces are several and depend upon the location in which they are built. These include acting as a sediment trap to help build new land, reducing wave fetch and erosion on adjacent marsh shorelines, creating habitat for fish and waterfowl, and improving water quality to promote the growth of aquatic vegetation. Terracing projects constructed under CWPPRA have achieved each of these goals, with sediment trapping being most evident near the openings of sediment-laden bays or navigational waterways.
Terracing has become a widely used technique that is expanding across the Gulf Coast because of the success and cost-effectiveness demonstrated through CWPPRA and privately funded projects. Although these features may not look like natural marsh and often use geometric configurations, they are able to perform a lot of the functions of natural marsh in areas that have become vast open water. Developing this cost-effective technique for use in areas that have few other restoration options is a testament to CWPPRA’s ability to adapt to funding constraints and a quickly changing environment.
CWPPRA Restoration Technique: Freshwater and Sediment Diversions
The present location of the Mississippi River has been confined by levees constructed in response to the devastating flood of 1927. Although necessary for protecting life and property, the levees prevent the natural processes of delta building and sediment deposition that are vital for sustaining wetlands. Without this nourishment, the wetlands will eventually succumb to subsidence, storms, and anthropogenic impacts.
The CWPPRA program has been finding solutions to optimize river resources and help rebuild wetlands with minimal impact to other stakeholders. Controlled diversions route river water through strategic locations in the levees to feed starving marshes. Crevasses, or cuts, are constructed through levees to allow passive creation of smaller deltas. Siphons suction fresh river water and direct flow into wetlands suffering from saltwater intrusion. Water-control structures and channel maintenance help distribute river water diverted from large-scale structures constructed under other authorities.
The river presents the greatest opportunity for rebuilding land but also the greatest challenges, as competing needs are inevitable. The human and natural environments must be able to coexist because they are inextricably connected. Together with stakeholders, CWPPRA projects are helping to reverse land loss on an ecosystem scale and support the economy on which coastal Louisiana has come to depend.
Barrier islands are known as coastal Louisiana’s first line of defense against destructive storm surge. These islands are a unique composite of beach, dune, marsh, and sand flats that host a tremendous variety of fisheries and wildlife, including endangered species. Barrier island restoration projects are designed to protect and restore the features unique to Louisiana’s barrier island chains. This type of project may incorporate a variety of restoration techniques, such as the placement of dredged material to increase island height and width, the placement of structures to protect the island from erosive forces, and the placement of sand-trapping fences, used in conjunction with vegetative plantings, to build and stabilize sand dunes.
Responsible for the majority of Louisiana barrier island restorations to date, CWPPRA has led the charge in barrier island restoration because it recognizes the ecological importance of barrier islands and their critical role in the defense of coastal Louisiana.
Louisiana’s shorelines are eroding at a drastic pace, some at rates up to 50 feet per year. The fertile but fragile soils found in the wetlands are susceptible to wave energy. As land is lost, water bodies merge together, which can increase wave fetch and shoreline erosion. Behind these shorelines lie communities, highways, and infrastructure that are at risk of washing away.
Various techniques to defend the coastline have been tested and applied under CWPPRA. Rock revetments, oyster reefs, concrete panels, and other fabricated materials have been constructed along otherwise unstable shorelines to abate wave energy and reduce erosion. These structures are designed to break waves, and they often trap waterborne sediments behind the structures that, over time, can become new land.
Through the course of the CWPPRA program, advancements have been made in shoreline structures that have helped maintain natural processes while providing critical protection. Such advancements have included using lighter-weight materials that require less maintenance and can be constructed on organic sediments. Other advancements include low-relief structures that are designed to trap sediments and natural breakwaters such as reefs that can self-maintain and support other ecological functions. Other natural shoreline protection measures include vegetative plantings, whose roots help secure soils and can promote accretion. These projects are implemented with consideration for minimizing impacts to the surrounding environment. Although some shoreline structures may look foreign in a natural landscape, they are necessary features that physically protect communities and hold wetlands in place by mitigating the harsh forces that move to destroy them.
Plants are a vital piece of healthy and sustainable wetland ecosystems. Plants are the base of the food chain and can build new layers of organic material on top of wetlands which helps them keep pace with subsidence and rising waters. Wetland vegetation reduces erosion primarily by dampening and absorbing wave and current energy and by binding and stabilizing the soil with roots. Coastal wetland plant species are indicators of soil and hydrologic conditions. The amount and salinity of water in an area influence which plants grow there. Scientists often classify Louisiana marshes into four types: fresh, intermediate, brackish, and saline.
The Coastal Wetlands Planning, Protection, and Restoration Act puts native wetland plant benefits to use through restoration techniques that include vegetative plantings. Vegetative planting projects are used both alone and in conjunction with barrier island restoration, marsh creation, shoreline protection, and sediment and nutrient trapping restoration techniques. These projects use flood-and salt-tolerant native marsh plants that will hold sediments together and stabilize the soil with their roots as they become established in a new area.
Environmental Studies students in Christina Hidalgo’s class at the Episcopal School of Acadiana do more than learn about general environmental issues; they also get outside and participate in direct monitoring of the ecosystems around them. On February 21st and 23rd they were joined by Coastal Wetlands Planning, Protection, and Restoration Act staff to discuss coastal habitats, the mammal species that call them home, and different wildlife monitoring techniques.
On Tuesday CWPPRA staff and ESA students discussed the importance of barrier beach systems for both human and wildlife communities, and students were given training in how researchers trap small mammal populations in those locations for monitoring. After students deployed small mammal traps around the ESA Cade campus on Wednesday, CWPPRA staff returned Thursday morning to help with trap collection and see what students had captured. In addition to trapping a variety of insects drawn to the oatmeal-soybean bait and several traps which had been moved by larger animals, ESA students successfully captured a marsh rice rat (Oryzomys palustris)!
These rodents are found throughout the Gulf and mid-to-south Atlantic coasts and as far inland as Illinois and Kansas. As the name suggests, marsh rice rats are generally found in wetland areas, although drier areas with dense grasses and sedges, while not ideal habitat, are also utilized. A native species in Louisiana, marsh rice rats can even be found out on barrier islands where their omnivorous diet lets them take advantage of both terrestrial food resources and items that wash ashore. The rat captured on the ESA campus was trapped near a stream and probably forages along that water body at night. Finding a marsh rice rat on a school campus is a reminder that wetland habitats come in a range of sizes and types and that we share those habitats with many different species.
Invasive species (harmful non-native species) are one of the most significant drivers of global change. Consequently, they can have substantial impacts on the economy, infrastructure, and humans. Society must address invasive species as a priority, which is exactly what National Invasive Species Awareness Week intends to do. The objective of National Invasive Species Awareness Week is to bring attention to the impacts, prevention, and management of invasive species – and all those who are working toward healthy, biodiverse ecosystems.
Wetlands provide benefits ranging from water filtration to storm surge protection; however, wetlands have become vulnerable to invasive species. Known as major contributors to wetland and coastal habitat loss, invasive species also threaten native species, including endangered species that rely exclusively on the wetlands for survival. The foreign animals that have been recognized as invasive to coastal wetlands include Asian carp, wild boar, island apple snails, and nutria. Invasive plant species include Chinese tallow, common reed, and purple loosestrife. Invasive animal and plant species have altered the health of wetlands by out-competing native species for food and natural resources, often without any natural predator or control to halt the resulting aggressive spread through an area. CWPPRA strives to protect wetlands by constructing methods to diminish the invasive threat and restore native species’ dominance and health within the wetlands.
For a full list of Invasive species in Louisiana, click here.
The invasive plant, giant Salvinia, was first observed in Chenier Plain marshes in 2009. Since then it has spread throughout most of the Louisiana Chenier Plain marshes. This plant can stack up above the water surface to as much as 6 to 12 inches. Under such conditions, oxygen exchange is greatly reduced, and decay of shaded Salvinia can easily cause anoxic conditions in affected areas. As a result, habitat quality of badly infested areas is severely degraded, and may affect many species typical of fresh marshes, including many species of management concern (alligator snapping turtle, mottled duck [including critical brood rearing habitat], wintering migratory waterfowl, black rail, king rail, little blue heron, whooping crane, and peregrine falcon).
LSU Ag. Center has a pond in Jeanerette, La. which is capable of producing weevil-infested Salvinia, but LSU does not have funding to operate a weevil production facility here. Costs associated with this project consists primarily of supplies and one part-time position to operate the pond, coordinate public weevil harvests, keep records of release locations, monitor Salvinia problem areas, assist landowners in conducting weevil release, relay infested Salvinia to new locations, and conduct public outreach to promote the program.
The Louisiana Salvinia Weevil Propagation Facility project is located coastwide.
This project was approved for Phase I, Phase II, and Operation in January 2017.
This project is on Priority Project List (PPL) 26.
The Louisiana Salvinia Weevil Propagation Facility project sponsors include:
The Louisiana Environmental Education Commission, Louisiana Department of Wildlife and Fisheries, and the Louisiana Environmental Education Association hosted the 20th Environmental Education State Symposium on February 3-4, 2017 at the Embassy Suites by Hilton in Baton Rouge, La. The theme of this year’s symposium was “protecting Louisiana’s endangered species.”
The Louisiana Environmental Education Commission (LEEC) provides environmental education news from across Louisiana, including information on environmental education programs, workshops, and grant opportunities. The state symposium furnished opportunities for formal and non-formal environmental educators from Louisiana and surrounding states to meet and share teaching techniques as well as multiple concurrent sessions for various topics and grade levels. Keynote speaker Dr. Jessica Kastler, Coordinator of Program Development at the Gulf Coast Research Laboratory’s Marine Education Center, used individual cases of endangered species to engage the audience in explorations of the process of science while cultivating environmental stewardship. In addition to the keynote speech, presenters in 15 concurrent sessions provided lesson demonstrations, hands-on workshops, and/or exemplary programs. The Coastal Wetlands Planning, Protection, and Restoration Act Public Outreach Staff was among exhibitors with a multitude of materials to assist teachers of all grade levels in furthering their students’ knowledge in environmental education and coastal protection.
World Wetlands Day is designated as a day to raise global awareness about the value and benefits of wetlands for both humanity and the planet; it is celebrated every February 2nd. Wetlands provide an immense number of benefits to not only the surrounding areas via protection, but also thriving aquaculture industries and commodities on both a national and international level. Healthy wetlands play a vital role in sustaining life and acting as natural safeguards in extreme weather events through disaster risk reduction.
The Coastal Wetlands Planning, Protection, and Restoration Act participated in the appreciation of wetlands by attending the World Wetlands Day Celebration on February 2nd, 2017 at the Bayou Terrebonne Waterlife Museum in Houma, La. The South Louisiana Wetlands Discovery Center hosted its 8th annual celebration by inviting third grade students from St. Matthews Episcopal School and Honduras Elementary, as well as sixth grade students from St. Francis de Sales Catholic School, totaling 185 local students, to learn about different aspects of wetlands. The CWPPRA Public Outreach Staff informed students about the relevance of wetlands by drawing connections between four different yet familiar types of wetlands and seafood, previous hurricane activity in the region, industry jobs, and wetland functionality. In order to do so, the CWPPRA staff incorporated the Where the Wild Things Are game to teach the students about wetland habitats and the animals living in them. This game consisted of students matching different wetland bean bag animals to the correct habitat: swamp, marsh, barrier island, and ocean. Where the Wild Things Are provides an opportunity for students to understand the connections between different wetland environments, recognize the adaptability of some animals to more than one habitat, and identify specific characteristics of each habitat, such as vegetation.