Oysters for Coastal Restoration

More than a seafood delicacy, oysters are an incredible natural resource. They are extremely helpful to our environment by filtering water, providing habitat, and controlling erosion. Adult oysters may filter up to two and a half gallons of water per hour, which in turn improves water quality. Oysters build reefs that provide habitat for fish, shrimp, crabs, and other aquatic animals. Oyster larvae need the hard, shell surface for settlement and growth. A special focus that has been put on oysters recently is their ability to control land erosion.

Oyster reefs have been constructed along eroding shorelines in an effort to lessen wave energy and ultimately reduce erosion. Seven of our nation’s fifteen largest shipping ports are located along the Gulf of Mexico. The wakes created by the cargo ships heighten erosion along an already disappearing coastline.

Globally, it is estimated that 85% of oyster reefs have been lost. Large-scale restoration projects can create man-made oyster reefs that duplicate many of the benefits of natural reefs. Oysters and the massive reefs provide a foundation for a healthy ecosystem. The Coalition to Restore Coastal Louisiana (CRCL) founded the Oyster Shell Recycling Program in 2014. This program collects shells from New Orleans area restaurants and utilizes the shells to restore fading oyster reefs that protect Louisiana’s coastline.  A majority of shell removed from the coast is not returned back to the waters. It is vital to Louisiana’s disappearing coastline that oyster shells are brought back to help as a line of defense for coastal restoration.

 

Hypoxia

Hypoxia

Hypoxia is the lack of oxygen in the water column. In the Gulf of Mexico’s Texas-Louisiana Shelf, hypoxia is defined as seasonally low oxygen levels (less than 2 milligrams/liter). This Gulf of Mexico “dead zone” is caused by input of excess nutrient pollution, primarily nitrogen, to the gulf from the Mississippi River. Due to an overabundance of nutrients, excessive algal growth (eutrophication) may result and demand large quantities of oxygen which decreases both dissolved oxygen in the water and available aquatic habitat in the water column. The significant decrease in levels of dissolved oxygen in the water column results in the death of fish and shellfish and/or in their migration away from the hypoxic zone. The northern Gulf of Mexico adjacent to the Mississippi River is the site of the largest hypoxic zone in the United States (8.5 million acres) and the second largest hypoxic zone worldwide. Freshwater and sediment diversions from the Mississippi and Atchafalaya Rivers may help reduce the hypoxic zone off Louisiana’s coast by channeling nutrient-rich waters into coastal wetlands, where the nutrients can be used or trapped by marsh and aquatic vegetation.

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Cameron Meadows Marsh Creation and Terracing

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Significant marsh loss in the Cameron Meadows area is attributed to rapid fluid and gas extraction beginning in 1931, as well as Hurricane Rita and Ike. Rapid fluid and gas extraction resulted in a surface down warping along distinguished geologic fault lines. During the hurricanes of 2005 and 2008, the physical removal of the marsh coupled with subsequent low rainfall has resulted in the conversion of intermediate to brackish marsh to approximately 7,000 acres of open water. In addition to these losses, significant marsh loss has resulted from saltwater intrusion and hydrologic changes associated with storm damages.

The goal of the project is to restore approximately 400 acres of coastal marsh habitat and reduce the fetch by constructing approximately 12,150 linear feet of earthen terraces. Sediment will be hydraulically dredged from the Gulf of Mexico and pumped via pipeline to create approximately 380 acres of marsh (295 acres confined disposal and 85 acres unconfined disposal). Funds are included to plant approximately 180 acres. Approximately 12,150 linear feet of earthen terraces will be constructed in a sinusoidal layout to reduce fetch and wind-generated wave erosion. Terraces will be constructed to +3.0 feet NAVD88, 15 feet crown width, and planted. Terrace acreage will result in four acres of marsh above Mean Low Water.

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The Cameron Meadows Marsh Creation and Terracing project is located in Region 4, Calcasieu/Sabine Basin in Cameron Parish, approximately five miles northeast of Johnson Bayou and five miles north of the Gulf of Mexico.

This project is on Priority Project List (PPL) 22. The 30% Design Review meeting was completed July 2015 and the 95% Design Review was completed in October 2016. In January 2017, the CWPPRA Task Force approved CS-66 for Phase II Construction.

The Cameron Meadows Marsh Creation and Terracing project sponsors include:

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

Wetland Nurseries

Did you know:

Wetlands provide a critical nursery for many of the Gulf of Mexico commercial fishery species.

One of the most significant fishery industries in the lower 48 states is the Gulf Coast fishery. Louisiana wetlands, particularly coastal marshes, play an imperative role in the life cycle of about 90% of Gulf marine species such as oysters, blue crabs, and shrimp. Providing a protective nursery, wetlands house an immensely diverse quantity of species that rely upon this habitat such as blue crabs, menhaden, and redfish. The Coastal Wetlands Planning, Protection, and Restoration Act aims to continue the protection and restoration, and health of these essential habitats for wildlife, aquaculture, and fisheries.

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