Welcoming the Brown Pelicans back to Rabbit island
At a glance
Rabbit Island in Louisiana was eroding, leaving brown pelicans without a place to breed. A restoration plan raised the island's elevation and built a dike, funded with $16.4 million from the Deepwater Horizon oil spill. After completion in Oct 2021, over 6,100 nests were observed, including 1,150 brown pelican nests. State and federal agencies worked together to increase resilience for all residents, including nesting birds and wildlife.
The threat of coastal erosion to brown pelican rookery on dwindling Rabbit Island
Dwindling Rabbit Island is the only brown pelican rookery in southwest Louisiana. Located in Cameron Parish’s Calcasieu Lake and accessible only by boat or aircraft, the island’s once 200 acres of land has shrunk to just 30 acres. Thanks to constant coastal erosion from storm surge, rising tides and major storms like Hurricane Katrina, much of the island gets flooded each time high tide rolls in.
We usually think of the shoreline when we say coastal erosion. But Rabbit Island also experiences inland erosion because of extreme wave action. The whole island’s altitude had shrunk, and most of the island had become open water or tidal wetlands at or slightly above sea level.
As a result, the brown pelicans and thousands of other birds nesting on the island had no safe place to breed. The eggs would get washed away and the birds could not raise their young in the degrading habitat. Present on the state flag, the brown pelican is the state bird of Louisiana, so preserving their habitat was critical to the state.
Using dredge fill to raise elevation and create optimal nesting and brooding habitat for brown pelicans
The project raised Rabbit Island’s elevation by using 389,388 cubic yards of dredge fill to construct optimal nesting and brooding habitat. Since the island is close to a ship channel, the mitigation plans had to protect the open navigation access. The dredge fill came from the ship channel, a beneficial reuse. Approximately 8,222 feet of 25-feet-wide containment dike was constructed around the island’s perimeter to protect against the tide.
We evaluated restoration benefits as well as potential impacts to the environment and human health that could result from the project. We found only temporary minor adverse impacts during construction, but huge long-term benefits, especially for the brown pelican.
The restoration plan and environmental assessment had to be finished in record time so final design and construction could begin before and after bird nesting season, between March and August.
The Coastal Protection and Restoration Authority of Louisiana approved our restoration plan in early 2020, and the project was funded with $16.4 million of settlement money from the Deepwater Horizon oil spill.
Elevation increase on Rabbit Island leads to successful nesting season and improved hurricane resilience
Building up the elevation of Rabbit Island deters incoming waves and high water levels. The next time Louisiana has a hurricane or tropical storm, Rabbit Island will be less affected by the high tides.
With construction completed in October 2021, Rabbit Island’s first nesting season after restoration far exceeded expectations. Roughly 370 nests were anticipated for the first season, but the Louisiana Department of Wildlife and Fisheries observed approximately 6,100 nests on the island, including 1,150 brown pelican nests.
This vital brown pelican habitat was restored thanks to state and federal agencies working together to increase resilience for all residents of coastal Louisiana – including nesting birds and other wildlife who call Rabbit Island home.
Would you like to learn more about our Rabbit Island restoration or our other environmental restoration projects? Come see me at the Innovations in Climate Resilience Conference from March 28-30 in Columbus, Ohio.