LDWF Constructs New Oyster Reef in Caillou Lake (Sister Lake)

Published 1:27 pm Monday, October 11, 2021

The Louisiana Department of Wildlife and Fisheries (LDWF) has completed the construction of a 200-acre oyster reef in Caillou Lake (Sister Lake) to increase oyster habitat and fisheries production. The construction process, known as cultch planting, is a proven habitat improvement technique used by LDWF.

This project was funded through Deepwater Horizon Natural Resource Damage Assessment (DWH NRDA) settlement dollars to restore for injuries to oysters that occurred as a result of the spill. The Louisiana Trustee Implementation Group approved 26 million dollars in oyster projects, including enhancing oyster recovery using broodreefs, cultch-plant oyster restoration, and hatchery-based oyster restoration.

Since 1917, LDWF has placed over 1.5 million cubic yards of cultch material on nearly 30,000 acres with positive results. This most recent 2021 Caillou Lake project spread approximately 29,500 cubic yards of crushed limestone on the lake bottom to create approximately 200 acres of artificial oyster reef.

When placed in a suitable oyster habitat, cultch material provides a substrate for free-floating oyster larvae to attach and grow, resulting in a mature, productive oyster reef.  Potential long-term benefits from increasing available cultch material include increased oyster production and oyster population connectivity, resilience, and stability. Healthy, interconnected oyster populations form reefs that provide the hard substrate needed for oyster larvae to settle, grow, and sustain the population. In addition to providing habitat for oysters, these reefs serve as a habitat for various marine organisms, from small invertebrates to large recreationally and commercially important species. Furthermore, oyster reefs provide structural integrity, improve water quality, and potentially reduce coastal erosion.

Caillou Lake was chosen because it has historically been one of Louisiana’s most productive oyster seed grounds.  According to the most recent stock assessment, a (365-acre) cultch plant constructed there in 2012 contained approximately 30 percent of the available oyster resources west of the Mississippi River.

The cultch plant will be closed to recreational and commercial oyster harvest for at least two years to allow time for oyster recruitment and growth.  LDWF will monitor the performance of the plant through regularly scheduled sampling events.

The Louisiana Department of Wildlife and Fisheries is charged with managing and protecting Louisiana’s abundant natural resources. For more information, visit us at www.wlf.la.gov. To receive LDWF email alerts, signup at http://www.wlf.la.gov/signup.