HomeTechnologyClimate change and the disappearance of islands threaten brown pelicans

Climate change and the disappearance of islands threaten brown pelicans


By CHRISTINA LARSON, AP Science Writer

CHAUVIN, La. (AP) — Bonnie Slaton, a seabird biologist and sliding off the side of her boat, wades through waist-deep water as brown pelicans fly overhead, until she reaches the shores of Raccoon Island.

During seabird breeding season, the site is a raucous symphony of noise and movement, and one of the few remaining havens for the iconic pelicans.

The crescent-shaped island is the last strip of land separating Louisiana from the Gulf of Mexico, a natural buffer against storms that come in from the sea. An hour’s boat ride from the mainland, the barrier island’s remoteness allows the birds to nest in mangroves and sandy beaches at a safe distance from most predators.

A dozen years ago, there were about 15 low-lying islands with nesting colonies of the Louisiana state bird. But today, only about six islands in southeastern Louisiana support brown pelican nests; the rest have disappeared underwater.

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“Louisiana is rapidly losing ground,” said Slaton, a researcher at the University of Louisiana at Lafayette. “Sea level sinking and rising are a double whammy.”

The disappearing islands threaten one of the most celebrated conservation success stories of the last century: the decades-long effort to save pelicans from the brink of extinction.

On land, brown pelicans are goofy-looking birds, their huge beaks and wings giving them what Slaton calls a “goofy” air. But soaring low over the ocean, their wingtips skimming the water, pelicans are streamlined and majestic.

The same forces that are swallowing up these offshore islands are also causing the saltwater marshes of southern Louisiana to disappear faster than anywhere else in the country. Scientists estimate that Louisiana loses the equivalent of a football field every 60 to 90 minutes.

“We are on the front lines of climate change. It’s all happening here,” said Jimmy Nelson, an ecologist at the University of Louisiana at Lafayette.

Visiting a seabird colony is like stepping into the hustle and bustle of a busy city, with neighborhoods of birds loosely grouped by species: pelicans, terns, egrets, spoonbills and gulls, all bringing food to the chicks.

As Slaton and two other biologists walk the shoreline of Raccoon Island, birds perch. The swirling, dizzying cacophony of feathered life heralds intruders. The songs of a thousand laughing seagulls are loud enough to drown out human thought.

As Slaton treks across the sand dunes to change batteries and memory cards for 10 tracking cameras on poles, his T-shirt is smeared with white bird droppings.

Motion-activated cameras are set up to observe pelican nests in various habitats. Some of the circular nests of smooth cordgrass are built on mangroves, others on grassy knolls.

Early birds take over mangrove attics, where nests have a better chance of surviving storms, Slaton explains. “Late nesters are on the ground, which is riskier.”

Camera data has shown that in recent years the main threat is flooding, which can wash away entire nests, as happened in April 2021.

Passing a nest on the ground, Slaton leans down to watch as two tiny featherless gray and pink pelican chicks squirm, eyes still closed. She believes they were born during the night or earlier in the day.

Within a week, the chicks are covered in fluffy white and gray feathers. When the parents are out of the nest, the older chicks stand guard, rocking and hissing at perceived threats.

Observing a seabird colony reveals both the promise and the fragility of a new life. Then, suddenly, the biologists are wiping white drops from their foreheads again.

Air raids don’t bother them. After all, copious bird droppings act as a natural fertilizer that helps shrubs and grass grow from the island’s sand and stones. Its roots retard erosion.

Without seabirds, the land would disappear much faster.

When Mike Carloss was a kid in Louisiana in the 1960s, he never saw brown pelicans.

Large shorebirds were among the first species declared endangered in the US in 1970. Like bald eagles, their populations had been decimated by the widespread use of DDT pesticides, which thinned the shells of birds. eggs and prevented healthy chicks from hatching.

The beloved pelicans were completely gone from Louisiana, where their image remained only on the state flag. But a protracted effort to bring them back led to one of the most inspiring comeback stories in the country.

After the US ban on DDT in 1972, biologists brought pelican chicks from Florida to repopulate empty islands in the Gulf of Mexico. More than 1,200 were released in southeastern Louisiana over 13 years.

One place was Raccoon Island, where Carloss, then a teenage field assistant at the Louisiana Department of Wildlife and Fisheries, remembers throwing fish off the beach to feed the baby chicks, as a kind of surrogate father.

“I took care of these young pelicans on a remote island,” he recalled. “Somebody had to hand feed them essentially.”

As a state wildlife biologist for more than two decades, Carloss oversaw various restoration projects on the island. But he now fears that if the islands continue to disappear, “we would go back to the 1960s, and not by poisoning.”

Protecting what remains depends on continued human intervention.

Today, one side of Raccoon Island is surrounded by granite breakwaters that divert the tides. Sand has been pumped in to fill in small gaps that are beginning to form.

Erosion is a natural process, and over thousands of years, most barrier islands rise and fall. Unlike volcanic islands, there is no bedrock, just layers of silt washed down by the Mississippi Delta.

Barrier islands, as environmental historian Jack Davis once wrote, “are precarious and impermanent places, at the mercy of wind and water that wash them, create them, shape them and destroy them.”

But rising sea levels and the increased frequency and intensity of storms related to climate change are accelerating the pace. And the islands have been deprived of new sediment from the Mississippi because the river’s course has been controlled since the 1940s with levees to prevent flooding and aid navigation.

“That prevents sediment from reaching rapidly sinking areas,” said Jaap Nienhuis, who studies erosion at Utrecht University in the Netherlands and previously conducted research in Louisiana. “Coastal Louisiana is losing land at perhaps the highest rate in the world.”

Every few years, government agencies undertake work to restore and maintain some of the barrier islands, a never-ending job. The money comes, for now, from a legal settlement after the 2010 Deepwater Horizon oil spill that killed hundreds of thousands of marine animals.

But it won’t last forever, and many sinking islands aren’t restored at all.

Another day, the biologists drive their aluminum boat past an unrestored island called Philo Brice. Mangroves grow in flooded lowlands, and pelicans nest in the upper branches, chicks stretching out as parents land with fish meals.

It is still a decent breeding habitat, as long as the soil is maintained and the plants remain above water. “In five or 10 years, it may or may not be here. It’s that fast,” Slaton said.

Flying in a small plane at 500 feet (152 meters), low enough to see pelicans’ heads poking out of the mangroves, the difference between Raccoon Island and unrestored Philo Brice is stark: one is dry land, the other is like soft bread that dissolves in a soup of blue.

When biologist Juita Martinez conducted research off the coast of Louisiana between 2018 and 2021, she found that the number of pelicans on another flooded, unrestored island, Felicity, dropped from 500 to about 20.

“In the last decade or two, we’ve lost so many pelican nesting sites,” he said.

Brown pelicans can live for more than 20 years, and in long-lived seabirds, the impact of reproductive problems takes time to become clear.

For now, pelicans remain common along the Louisiana coast, and their likenesses are everywhere: license plates, mugs, T-shirts, restaurant signs, and college stamps.

At the Bayou Boogaloo Music and Art Fair, the pelican artwork often sells out first, said New Orleans painter Patrick Henry, standing with his brightly colored bird portraits.

The brown pelican “is a symbol of Louisiana, just as the eagle is a symbol of America,” said Rue McNeil, executive director of the Northlake Nature Center in Mandeville, Louisiana. “It was put on the state flag because that particular bird represents a lot of strength.”

And “sacrifice,” he added.

Disappearing islands are not just a problem for birds.

On a recent afternoon, Theresa Dardar calls out to neighbors as she and her husband, Donald, cruise their small boat through the Pointe-au-Chien swamp in southeastern Louisiana.

Everyone knows everyone here in the close-knit community of the Pointe-au-Chien Indian Tribe. But his world is changing fast.

“This swamp, I used to ride through it with my grandfather. He could reach out and pull the grass on the ground on either side of the boat,” recalls Dardar. “But look how wide the water is now, all that land is gone.”

The boat passes a single white cross on a low bank, marking one of the tribe’s eight cemeteries in the swamp. The community is concerned that rising seas and storm surges will wash away their ancestors, memories and culture.

Dardar supports efforts to restore the islands. “I’m glad they’re doing that for pelicans, but they need to do it for humans, too,” he said.

Follow Christina Larson on Twitter: @larsonchristina

The Associated Press Health and Science Department receives support from the Howard Hughes Medical Institute’s Department of Science Education. The AP is solely responsible for all content.

Copyright 2022 The Associated Press. All rights reserved. This material may not be published, broadcast, rewritten, or redistributed.



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