Barrier-island loss dealing blow to birds
Wine Island was rendered one-tenth of its pre-Gustav size by the storm surge. Scientists say the dwindling island is an important habitat for nesting birds and must be preserved.
By Nikki BuskeyStaff Writer
Published: Saturday, March 27, 2010 at 6:01 a.m. Last Modified: Friday, March 26, 2010 at 11:20 p.m.
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HOUMA — Remote and shrinking, the Isles Dernieres barrier islands that lay dozens of miles off Terrebonne’s coast are most often discussed as sandy speed bumps for storm surges.
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But for thousands of sea birds, the islands are a vital, yet disappearing, link to life.
The islands have shrunk in size and number since the 2008 storms, as have the birds who reproduce there.
The islands, far away from the coast and predators that threaten their young, serve as a nesting place for terns, black skimmers, brown pelicans and others.
Nicholls State University researchers determined that about 44,000 pairs of birds mated and nested on the tiny islands in 2008.
A year later, the number dipped to about 28,000 pairs, a loss of about 36 percent, said assistant biology professor Aaron Pierce.
Researchers aim to keep a close eye on the island chain this summer to see if the decline continues.
With the birds’ preferred habitat rapidly disappearing rapidly, scientists acknowledge the outlook is grim.
“Let’s be clear — there is no recovery going on,” said Richard DeMay, a senior scientist with the Barataria-Terrebonne National Estuary Program.
Brown-pelican populations have increased, but only because the birds are recovering from near extinction blamed on a now-banned pesticide, DeMay said.
“The trends do seem to be headed down” for other species of birds, he said.
If the barrier islands continue to erode, DeMay said, “you’re going to be seeing fewer and fewer sea birds” in Terrebonne and Lafourche.
“Louisiana is the most important state for these colonial nesting seabirds in the Gulf of Mexico,” said Mike Carloss, coastal-operations manager for the Louisiana Department of Wildlife and Fisheries. The department manages the Isles Dernieres, including Raccoon, Whiskey, Trinity, East and Wine islands, as a natural refuge.
“Without the islands, they’re in trouble.”
LOSING WINE ISLAND
The birds prefer islands that are small and remote. Pelicans tend to nest in bushy vegetation. Terns nest on the sand.
Raccoon and Wine islands, smaller islands in the chain, host some of the largest colonies of nesting sea birds in the state, Carloss said. Raccoon Island fared well through Gustav and Ike.
But Wine Island has been reduced to almost nothing, and its plant life was eradicated. Many locals say it will be lost forever if it’s not rebuilt soon.
Terrebonne Levee Director Reggie Dupre, who flew over the island in February, estimates Wine Island, previously 55 acres, now measures about 5 acres.
In 2008, 11,000 pairs of birds nested on the tiny spit of land.
Just 6,800 pairs of birds returned to nest there in 2009.
The shrinking island likely resulted in increased competition for nesting sites, prompting some birds to nest in extreme conditions. Some pelicans nested directly on the sand, putting their nests so close to shore that they were flooded, Carloss said.
Few “will return to nest there in the future,” Carloss said. “There’s nothing left for them there.”
State wildlife biologists are pushing for Wine Island’s restoration because it’s one of the state’s larger breeding colonies, but the state has no restoration plans, said Chris Macaluso, a spokesman for the state Office of Coastal Activities.
Also, despite protests at public meetings, the island is not included in the U.S. Army Corps of Engineers’ plan to restore Terrebonne’s barrier islands. Scientists have deemed the island “unsustainable,” Macaluso said.
“It’s extremely susceptible to being washed away,” Macaluso said.
Since 1991, Macaluso said, dirt dredged from the Houma Navigation Canal has been used at least four times to bolster the island.
The last project was in 2007, but Gustav and Ike swept away most of that material.
Macaluso said dredged mud will be used on Wine Island in the future, but he couldn’t say when that might happen again.
So what does that mean for the birds who depend on the island to reproduce? Scientists aren’t sure.
They say many sea birds fled the rapidly degrading Chandeleur Islands off the coast of St. Bernard Parish to Terrebonne’s islands. But the birds’ options, in Louisiana at least, are lessening.
“The loss would not be good,” Pierce said. “We host the largest pelican colony in the state. And, for birds like royal and sandwich terns, these islands host a significant portion of their breeding population.”
DeMay, Pierce and Carloss tried to remain positive about the prospect of keeping the islands viable, both for storm protection and birds.
“It depends on how important society views these islands to be and the commitment we’re willing to make,” Pierce said.
It will require millions in maintenance, dredging and rebuilding.
Nicholls researchers are hoping their work will help determine ideal nesting conditions so future restoration projects take those needs into account.
“We’re spending a tremendous amount of money to save the islands for hurricane protection. We’ve spent $50 million just to maintain these land masses,” Pierce said. “Our idea was more than providing just a land mass, maybe there are things we can do to restore the ecosystem function.”
DeMay said protecting the islands is key to the survival of local communities, both human and bird.
“Huge percentages of the national bird populations nest here in Louisiana, and there are three to four species that nest on those islands alone,” DeMay said. “When we lose those barrier islands, particularly the smaller ones like Wine Island, for the species as a whole — it will make an impact.”
Staff Writer Nikki Buskey can be reached at 857-2205 or email@example.com.