NEW ORLEANS, La. (AP) - Last Thursday morning, the Cat Islands in Barataria Bay looked like a slice of brown pelican heaven. Every mangrove bush seemed crowned by a nest, and each nest was home to a group of youngsters, from the tiny, hairless newborns that resemble dinosaurs more than birds, to the gangly adolescents trying to test their emerging plumage. And each nest was guarded by at least one vigilant parent while other adults were wheeling across the blue sky hunting for finned meals in the sparkling green waters below.
Two years ago, the world wondered if this rite of spring would ever occur here again. As a major landfall for the oil pouring out of BP's blown Deepwater Horizon rig, Barataria Bay was being pummeled by one of the worst environmental muggings in the nation's history. Poisonous hydrocarbons laced the surface of the bay in ugly red strips, became embedded in the silty bottom, and washed up against the mangrove islands. All this just as the state bird -- only recently returning from a 37-year stay on the endangered and threatened list -- was at the height of its nesting season.
Pictures of the great birds struggling to rise from the oiled surface, their bodies and out-stretched wings draped in brown sludge, flashed around the world, becoming the iconic image of the disaster. As scientists watched youngsters burst into the world from oil-coated eggs only to be fed fish from the polluted waters by parents sticky with poison, they wondered: Would the bay's populations of pelicans, and their sea and shorebird cousins, collapse?
Any tour of the bay the last two springs would seem to provide a resounding "no" to that question. The number of birds nesting appears as high as before the spill.
Yet while researchers and staffers from environmental groups like the Audubon Society say they are happy so far -- it's the "so far" that concerns them.
Like the microbes of a deadly contagion, components of the oil that infiltrated this ecosystem can remain toxic for decades, posing a viable threat to its population of fish and wildlife that entire time.
"Just as we can't see germs to avoid them, birds don't have a way to recognize oil as a threat in their environment," said Melanie Driscoll, Audubon's director of bird conservation for the Gulf Coast and Mississippi Flyway.
Birds will eat worms that have been feeding on algae in tar balls, consume fish contaminated with components of oil that can cause damage to internal organs, and continue to wade on shorelines, swim in waters and nest on islands that still have oil releasing toxins that can disrupt their ability to reproduce, she said.
"They are helpless to protect themselves in the face of this type of threat," Driscoll said. "They will go back to the places they always go, because they can't recognize the harm in doing so.
"So we won't know how much harm is done for years to come."
In fact, the public can't be certain how much harm has been done so far. State and federal agencies responsible for wildlife have been hard at work on the Natural Resources Damage Assessment, which will determine how much BP and its partners will owe for damage caused by their spill. They are measuring populations as well as any presence of toxins in the birds. But government lawyers have put all results under wraps to avoid giving any edge to the responsible parties in what is likely to be a long, contentious legal process.
However, until May 11 last year, the U.S. Fish and Wildlife Service, responsible for birds affected by the spill, published the results of its efforts. By then, it had collected 6,983 dead birds of all species, 664 of which were brown pelicans. Another 162 oiled pelicans were collected, rehabilitated and later released.
Authorities agree the actual number of birds killed and otherwise affected by the spill will be greater than those actually collected. Some dead birds floating in the bays are missed, while others may fall in the dense wetlands, get carried out to the Gulf by the tides or be consumed as carrion by other animals.
Monitors can't be sure there hasn't already been a serious die-off, Driscoll said. The Texas population of brown pelicans has been expanding, and researchers know some of those birds have been moving east into Louisiana. So there is a possibility any holes created in the Barataria Bay population by the oil could have been filled by Texas transplants.
"We hope the birds we're seeing are the same birds that were here during the spill, but we just don't know," she said. "And while it looks like we haven't seen a significant drop-off, we don't know. If (agencies) were taking a census, they won't release that information right now."
The first sign of trouble might come next spring when the birds hatched during the spill reach three years, the age at which many typically begin reproducing.
"We know from previous spills and studies that birds that survive the initial exposure to oil later have reduced reproductive success, fewer of their eggs hatch, and the young from eggs produced in an oiled environment may show a failure to survive or to grow," Driscoll said.
Researchers have been looking at reports on the 1989 Exxon Valdez spill in Alaska's Prince William Sound for guidance of what to expect. On the plus side, most seabird species impacted there recovered within the next five to 10 years. On the down side, the population of pigeon guillemots, which feed on mostly fish, crabs and invertebrates in the intertidal zone, crashed and have not recovered.
That's the same menu favored by brown pelicans and a host of shorebirds such as herons, ibis, plovers, skimmers and rails -- some of which already were in stressed conditions before the spill.
Just as worrisome is news contained in the 20th anniversary report issued by the Exxon Valdez trustees in 2009 on the status of restoration in Prince William Sound. Its first paragraph states: "one of the most stunning revelations ... over the last 10 years is that Exxon Valdez oil persists in the environment and in places is nearly as toxic as it was the first few weeks after the spill."
While the sub-tropical Gulf ecosystem can degrade oil and its components faster than cold Alaska, that job has yet to be done. Two years out, BP's oil remains in liquid form just below the surface in the few marsh areas that were heavily oiled, such as Bay Jimmy. And it is constantly re-exposed in the form of tar balls and tar mats on shorelines all along the coast after high winds, meaning birds and other wildlife will continue to be at risk.
"Worms eat algae that are growing on those toxic tar balls and mats, pelicans and shorelines eat those worms or walk across the tar," she said. "We don't know the extent of damage now, and we can't predict with certainty what it will be.
"But what we do know is that continued exposure to these highly toxic substances will cause damage."
Conservation groups point out the spill aggravated the far greater threat to pelicans and other wildlife: The continuing loss of the battered and sinking coastal wetlands that serve as their habitat. Fears that the spill hastened the demise of vanishing nesting sites, by killing mangroves with root-choking layers of oil, seem to be coming true. Most of the islands in Barataria Bay that have been traditional nesting sites for pelicans and other birds now are ringed by a border of dead or dying mangroves.
The birds using those islets this spring seemed blissfully unaware of the horror that flowed across their homes two years ago, or the question marks that loom over their future. Pelicans, roseate spoonbills, ibis, herons, skimmers and gulls were noisily going about the business of bringing another generation into the world. For now, at least, Barataria Bay seemed like an ideal home.
Information from: The Times-Picayune, http://www.nola.com