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Pelicans and seagulls stand on the shore not far from a containment boom after the 2010 Gulf of Mexico oil spill.

A boom line floats just off the Mississippi coast, part of the effort to protect wildlife like the two brown pelicans and seagulls on this Gulfport beach Thursday.

Photograph by William Colgin, the Sun Herald via AP

Craig Guillot

for National Geographic News

Published April 30, 2010

The elegant yet fragile brown pelican—removed from the U.S. endangered species list just last year—is the animal that conservationists fear may come to symbolize the damage to wildlife as the Gulf of Mexico oil spill advances over its marshy habitat.

In nesting season, the birds lie in the direct path of what officials fear may become one of the biggest oil spills in the nation’s history.

(Pictures: Gulf Oil Spill Hits Land—And Wildlife.)

Even though the state bird of Louisiana, once on the brink of extinction, has recovered greatly in numbers overall, the brown pelican still has struggled along the shores of the Pelican State because of assault from harsh weather and oil spills. In fact, for 13 years, wildlife officials tried to aid the pelican’s recovery here by capturing young birds in Florida and bringing them to Louisiana.

"The brown pelican was just pulled off the endangered species list, and they are sitting on nest in the barrier islands … the first point of contact for oil," said Melanie Driscoll, director of bird conservation for the Louisiana Coastal Initiative of the National Audubon Society. She said that many coastal birds are now getting ready to pair bond, court, and nest. Louisiana's coast serves as a winter resting spot for more than 70 percent of the country's waterfowl and is used by more than 100 tropical migratory birds, she added.

How sensitive are the birds to oil spills?

In 2005, state officials tracked a 35.2 percent decline in brown pelican production due to that year’s hurricanes, including Katrina, and one oil spill in Breton Sound near Plaquemines Parish. More than 400 birds were killed and 1,000 more were covered in oil when equipment on an oil platform leaked. The size of the spill: 15 barrels (630 gallons/2,385 liters).

Now, federal authorities believe 5,000 barrels (210,000 gallons/794,937 liters) of oil per day are flowing into the Gulf of Mexico from a BP-leased well on the sea floor, site of the April 20 explosion that destroyed the Deepwater Horizon drilling rig and killed 11 workers.

(See "Rig Explosion Shows Risks in Key Oil Frontier.")

BP’s efforts to stop the deepwater leak with remote-controlled submarines so far have failed. Multiple other efforts to control the spill are underway—including construction of a containment system, controlled burns of the oil, and the drilling of relief wells—but those efforts could take weeks or months. Homeland Security Secretary Janet Napolitano, who is among a group of Cabinet members touring the site today, has declared the Gulf of Mexico oil slick “a spill of national significance,” and the military may be called in to aid in the efforts to combat it.

Oil Hits the Delta

On Thursday night, the oil made its first landfall: Louisiana's “bird’s foot” delta and barrier marshes. Over the weekend, the oil is expected to reach Mississippi and Alabama and Officials of the joint federal-industry response team said that more than 217,000 feet (66,142 meters) of boom have been deployed to try to protect ecologically sensitive areas, and that loud cannons have been fired in an effort to haze the birds from the water’s edge.

(See Oil Spill From Sunken Rig Site May Be Serious )

Michael Ziccardi, a biologist and director of the California-based Oiled Wildlife Care Network, whose group helped in the rescue of brown pelican chicks during the 2005 Breton Sound spill, says it is on standby, ready to deploy to the Gulf Coast.

Birds like the pelican are vulnerable, he said, because they normally use their feathers as a wet suit. When the oil covers them, it creates open holes in that barrier of feathers and allows water to get against their skin. Because birds have normal body temperatures between 39.4° and 41.1°C (103° and 106°F), heat loss in the water can be fatal.

“They can't maintain that temperature and have to come ashore to stay warm, but when they're ashore, they can't eat,” he said. “It just creates a vicious cycle."

(See Gulf Oil Spill Pictures: Aerial Views Show Leak's Size)

Otters and Sea Turtles in Danger

Ziccardi said many other animals are at risk as well, including heavily furred animals such as otters and nutria. Dolphin and whales can get skin irritations, and sea turtles are susceptible to oil ingestion because they often come to the surface to feed. It is an especially vulnerable time for the sea turtles because they are entering their spring nesting season.

It’s also a dangerous time of year for oil to hit the state’s fisheries, which produce more than a third of the nation’s seafood, including blue crab, shrimp, and fish, according to the Louisiana Seafood & Promotion Board.

State fisheries managers said local fisheries are especially vulnerable because speckled trout (spotted sea trout) have started spawning, oysters have started reproducing larvae, and white and brown shrimp are in transit to the estuaries.

Harry Blanchet, Finfish Program Manager for the Louisiana Department of Wildlife and Fisheries, said that while mature fish can often swim away from oily waters, fish in the early stages of life are at great risk. Larvae and post-larvae are likely to consume oil directly or through the plankton and other food that they eat.

"Fish are mobile. If there is something in that oil they can avoid, they'll do that, but some of the early life stages just aren't capable of that kind of movement," said Blanchet.

In all, more than 400 species of birds, amphibians, reptiles, and mammals in the estuaries along Louisiana's coast and surrounding waters could be affected by the oil, says Karen Foote, biologist administrator of marine fisheries for the Louisiana Department of Wildlife and Fisheries. Areas that have already been identified for impact include the Delta National Wildlife Refuge, the Pass-a-Loutre Wildlife Management Area, the Chandeleur Islands, and the Gulf Islands National Seashore.

But the risk doesn’t stop at the shoreline. Foote says hundreds of inlets, bays, and bayous could carry the oil farther inland. With tides of more than a foot and little elevation on the coast, the oil could inundate the deep interior of the wetlands.

"The oil follows the water. If the currents and tides bring it in, it's just going to go wherever the water goes, and it [could travel for] miles," said Foote.

Biologists say it could be years before they know the full ecological impact of the oil.

(Related blog: "Who's Still Spilling Oil in the Seas?")

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