Wetland Marshes

Marsh is a type of wetland that is continuously flooded with water. Emergent-soft stemmed vegetation is present in marsh due to the saturated soil conditions. In Louisiana, there are four types of wetland marsh: freshwater, intermediate, brackish, and salt. Marshes are classified according to the salinity of the water. The location of Louisiana marshes in relation to the Gulf of Mexico often directly correlates to the level of salt content in the water. Salinity also changes based upon rainfall, drainage, soil texture, vegetation, depth of water table, and freshwater inflow.

The salinity range for each marsh type is as follows:

  • Freshwater – 0 ppt (parts per thousand)
  • Intermediate – 0-5 ppt
  • Brackish – 5-15 ppt
  • Salt – 15 or greater ppt

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A wide variety of animals such as nutria, turtles, and many bird species can be spotted in the freshwater and intermediate marshes of Louisiana, as well as species of special concern like Louisiana black bears and Calcasieu painted crawfish. The exchange between freshwater and salt water is frequent in the state of Louisiana due to its close proximity to the Gulf of Mexico. An estuary is characterized by this mixture of freshwater and salt forming brackish water where many wetland species spend their juvenile lives. The estuaries of coastal Louisiana support economically important fisheries and provide important wildlife habitat. Crabs, fish, and shrimp are a few of the animals found in Louisiana’s salt marsh, and birds like brown pelicans and reddish egrets often nest in the shrubby vegetation bordering salt marshes. Each of these marsh types play a significant role. It is vital to keep these marshes healthy for them to maintain their value and support the people, plants, and animals of Louisiana.

 

 

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Cole’s Bayou Marsh Restoration

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Project area wetlands are undergoing loss at -0.42 %/year
based on 1983 to 2011 USGS data from the extended
boundary. Wetland loss processes in this area include
subsidence/sediment deficit, interior ponding and pond
enlargement, and storm impacts resulting in rapid episodic
losses. In addition, significant interior marsh loss has
resulted from salt water intrusion and hydrologic changes
associated with increasing tidal influence. As hydrology in
this area has been modified, habitats have shifted to more of
a floatant marsh type, resulting in increased susceptibility to
tidal energy and storm damages. Habitat shifts and
hydrologic stress reduce marsh productivity, a critical
component of vertical accretion in wetlands.

The specific goals of the project are: 1) create 365 acres of
brackish marsh in recently formed shallow open water; 2)
nourish 53 acres of existing brackish marsh; and, 3) increase
freshwater and sediment inflow into interior wetlands by
improving project area hydrology.

This project aims to create 365 acres and nourish 53 acres of
brackish marsh via dedicated dredging with borrow from
nearby Vermilion Bay. Although Vermilion Bay is not
considered an “external” source of material, significant
sediment inflows into this area may result in some borrow
area infilling. Half of the marsh creation acres would be
planted. The project will encourage additional freshwater
nutrient and sediment inflow from Freshwater Bayou Canal
by dredging a portion of Cole’s Bayou along with the
installation of a series of culverts throughout the project
area.

The culverts located along the northern project boundary are
envisioned to allow the ingress of sediment, water, and
fisheries organisms into the semi-impounded project area,
but avoid backflow of water and potential loss of interior
marsh sediment (i.e., north to south flow only). The culverts
located along the southern project boundary are envisioned
to allow water to drain out of the marsh.

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This project is located in Region 3, Teche/Vermilion Basin,
Vermilion Parish, east of Freshwater Bayou Canal.

This project is on Priority Project List (PPL) 21.

The Cole’s Bayou Marsh Restoration sponsors include:

 

National Estuaries Week

On August 3, 2017, the Senate unanimously approved a resolution designating the week of September 16th through September 23rd as National Estuaries Week.

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Over 100 million people nationwide live near estuaries and use these resources in their daily lives through agriculture, tourism, commercial fishing, power generation, and as shipping ports. Estuaries, where the river mouths meet the ocean, are where fresh and saltwater mix.  One of the most expansive and productive estuaries in the world is located in the United States at the interface of the Mississippi River and the Gulf of Mexico. Along with providing jobs, estuaries have one of the highest productivity rates among ecosystems in the world. Estuaries serve as habitat for fish, waterfowl, and a variety of other wildlife by providing food and shelter during migration and mating season.

Estuaries are a well-known hotspot for recreational fishing. Take part in celebrating National Estuaries Week by reeling in a big catch while helping to keep your estuary areas clean of trash and healthy for the wildlife and vegetation. Visit our friends over at the Barataria-Terrebonne National Estuary Program for a list of activities and ways you can participate in National Estuaries Week.

Estuaries

An estuary is an ecosystem comprised of both the biological and physical environment, commonly located where a river meets the sea. Estuaries are inhabited by an array of plant and animal species that have adapted to brackish water—a mixture between freshwater draining from inland and salt water. One of the most expansive and productive estuaries in the world is located in the United States at the interface of the Mississippi River’s freshwater and the salt water from the Gulf of Mexico.

Estuaries have one of the highest productivity rates among ecosystems in the world; they provide an abundance of food and shelter as well as breeding and migration locations. Estuaries also provide great access for enjoyable recreational activities such as fishing. Continue your love for estuaries and contribute to their well-being by aiming to keep your estuary areas clean of trash and healthy environments for wildlife, vegetation, and others to enjoy!

Share the estuary love for Valentine’s Day! #iheartestuaries

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Wetland Marshes

Did you know:

There are four different types of wetland marshes in Louisiana.

Due to Louisiana’s proximity to the Gulf of Mexico, the exchange between fresh and salt water along the coast is frequent. Depending on the location of the marsh, it could be classified as either freshwater, intermediate, brackish, or saltwater marsh. Marshes are categorized by the salinity, or salt content, of the water, and the location of marshes to the Gulf of Mexico often directly correlates with the salinity level. Generally following a salinity gradient, freshwater marshes are commonly situated furthest inland from the gulf with a salt content of 0 ppt (parts per thousand), intermediate marshes contain a salinity range of 0-5 ppt, brackish marshes have a range of 5-15 ppt, and saltwater marshes encompass a salt content of 15 ppt or greater. Within the marsh gradient are estuaries, where fresh and salt water mix and many wetland species spend their juvenile lives.

 

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