Deepwater Horizon N. Breton Island Restoration

Pre-Breton restoration monitoring looks at the base of the food chain

North Breton Island is a barrier island located a 45-minute boat ride from Venice, Louisiana. For thousands of years the island, which is part of the Breton National Wildlife Refuge, has slowly eroded away due to natural conditions such as severe storms. The island’s lost shoreline has translated into lost habitat for numerous federally protected birds.

Unfortunately, North Breton Island has suffered from man-made disasters, too. Like many other barrier islands in the Gulf of Mexico, it was negatively impacted by the 2010 Deepwater Horizon oil spill. Fortunately, this disaster has come with a silver lining, of sorts -- funding for the island’s restoration paid for by BP, the company primarily responsible for the spill. 

The Deepwater Horizon NRDA Trustee Council will use $72 million from the historic settlement with BP to increase the extent of North Breton Island by hundreds of acres. The additional acreage will provide nesting habitats for threatened and endangered birds such as the brown pelican and least tern. It will also benefit the red knots and piping plovers that forage for food there in the winter.

A buffet of worms, crustaceans and other invertebrates feeds hungry shorebirds

 “We don’t expect the project will impact the red knot and plovers, but it will impact their food source,” says Robin Donohue, a biologist from the U.S. Fish and Wildlife Service. He recently joined other Service and U.S Geologic Survey biologists in establishing the pre-restoration project abundance and species composition of the worms, crustaceans and other invertebrates that call North Breton Island’s shoreline home. “These small animals are incredibly important in that they’re the bottom of that beach-foraging food chain,” Donohue says. “For virtually all of your shorebirds –- that’s what they’re looking for.”

Using a soil sampling tube, Donohue and his colleges took samples of the shoreline from the surface down to 5 cm deep (the maximum depth at which red knots and piping plovers are thought to search for food).

A USGS expert is examining the samples to determine the shoreline’s invertebrate population now, before construction starts in 2019. After approximately 8.2 million cubic yards of sand, silt, and clay dredged from a nearby borrow site is put into place and the North Breton Island shoreline is reconfigured, biologists will take samples again in order to compare the post-construction invertebrate population with the pre-project baseline.

With those hungry shorebirds and other species in mind, the biologists are aiming to have at least 70 percent of the pre-project invertebrate populations established within two years of the project’s completion. That would be a normal rate of return, and they’ll be looking for it to ensure the restoration effort is on track.

“Through our sampling, we will have an idea of the beach critter community,” says Chris Pease, another Service biologist who was involved. “And after we add new sand to the island as part of our restoration efforts,” he says, “we will know if the birds will have as good of a buffet as before.”