Bio-Engineered Oyster Reef Demonstration (LA-08)

LA-08

Purpose:

The purpose of this project is to test a new, bio-engineered, product to address rapid shoreline retreat and wetland loss along the Gulf of Mexico Shoreline in areas with soils of low load bearing capacity. For example, at Rockefeller Refuge, the direct Gulf of Mexico frontage and extremely low soil load bearing capacity (250-330psf), coupled with an average shoreline retreat of 30.9 ft/yr, present unique engineering challenges with a subsequent direct loss of emergent saline marsh.

Restoration Strategy:

The goal of this demonstration project is to evaluate the proposed technique as a cost effective technique for protecting areas of Coastal Louisiana’s Gulf of Mexico Shoreline with poor load bearing capacities.The demonstration project would consist of an Oysterbreak, approximately 1000′ long. The Oysterbreak is a light-weight, modular shore protection device that uses accumulating biomass (an oyster reef) to dissipate wave energy. The bio-engineered structure is designed to grow rapidly into an open structured oyster reef utilizing specifically designed structural components with spat attractant (agricultural byproducts) and enhanced nutrient conditions conducive to rapid oyster growth.

Required Monitoring: [1]

  • Topographic and bathymetric surveys (elevation, water levels)
  • Ground-level photography
  • Aerial photography
  • Wave attenuation (wave energy effects)
  • Oyster and Water quality monitoring

The Oysterbreak is constructed by placing modular units into an open interlocked configuration. The units are sized to be stable under storm wave conditions. The height and width of the Oysterbreak are designed to achieve a moderate initial wave energy reduction. As successive generations of encrusting organisms settle on the Oysterbreak, the structure’s ability to dissipate wave energy increases.

Location:

The project is located along the Rockefeller Wildlife Refuge Gulf of Mexico shoreline west of Joseph Harbor canal in Cameron Parish, Louisiana.

pic_LA_08

Project Effectiveness: [2]

The oysterbreaks are providing habitat for oyster settlement and the top layers of rings should be the most likely to support oyster colonies. Recommended improvements include:

  • Types of cement applications
  • Lessening the space available for coastal erosion (the gap between coast and oysterbreaks needs to reduce to prevent further erosion).
  • Crest elevation between the oysterbreaks performed well in wave attenuation and shoreline erosion
  • Increase the height of the structure to improve wave breaking potential

aerial_rings

Progress to Date:

The cooperative agreement between the National Marine Fisheries Service and the Louisiana Department of Natural Resources has been executed. Construction was finalized in February 2012. This project is on Priority Project List (PPL) 17.

More Information on this Project:

Further Websites Regarding Oyster Reef Restoration:

 

 

Work Cited:

[1] McGinnis and Pontiff. (pages 4-6) LA-08 2012 Operations, Maintenance, and Monitoring Plan, 30 April 2018, https://www.lacoast.gov/reports/project/4224379~1.pdf

[2] McGinnis and Pontiff. (page 22) 2014 Operations, Maintenance, and Monitoring Report for Bioengineered Oyster Reef Demonstration Project (LA-08)

 

 

Leave a Reply

Fill in your details below or click an icon to log in:

WordPress.com Logo

You are commenting using your WordPress.com account. Log Out /  Change )

Twitter picture

You are commenting using your Twitter account. Log Out /  Change )

Facebook photo

You are commenting using your Facebook account. Log Out /  Change )

Connecting to %s