15 Jun 2010
A Louisiana Bird Expert Assesses Damage from the Spill
The images of pelicans and other Gulf of Mexico seabirds drenched in oil have stirred sadness and outrage around the world. But, says conservationist Melanie Driscoll, the unseen effects are probably far greater, with some birds perishing out of sight, far from shore, and others facing spill-related declines in the fish on which they depend.
Before the oil spill in the Gulf of Mexico, Melanie Driscoll — director of bird conservation for the National Audubon Society’s Louisiana Coastal Initiative — faced a sufficiently daunting task: Identifying and protecting prime bird habitat in that state’s beleaguered coastal marshes. Louisiana’s wetlands had been disappearing for decades, starved for soil and nutrients as massive flood-control projects diverted the flow of the Mississippi River and then carved up by canals and infrastructure for the booming oil industry.
In the past two months, with the blowout of the Deepwater Horizon oil rig, Driscoll’s challenges have grown far more severe. Wetlands and barrier islands battered by hurricanes and the oil industry are now slowly being bathed in a tide of crude oil, threatening tens of thousands of birds nesting in marshes and on barrier islands. In recent weeks, Driscoll has spent many hours along the Louisiana coast, taking censuses of seabirds, assessing threats to birds and their habitat, and helping in the effort to find, and clean, oil-covered birds.
Kim Hubbard/Audubon Magazine
In an interview with Yale Environment 360
senior editor Fen Montaigne, Driscoll talked about the spill’s impact on threatened species, including brown pelicans and Wilson’s plovers; described the ways, visible and invisible, that the spill is killing birds; and discussed her emotions as she watched sanderlings and other species go about the business of mating and nesting as the spreading oil began to hit the Louisiana coast.
It’s too soon to tell, said Driscoll, what the lasting impact of the spill will be on the birds of the Gulf Coast. But she said the spill has underlined the critical need to restore Louisiana’s wetlands and marshes and the abundant birdlife they harbor. “One of the reasons Audubon has always focused on birds is intrinsically for the birds,” said Driscoll. “But birds are also indicators of what we’re doing to our environment.”
Yale Environment 360:
Could you paint a picture for our readers of the growing toll that the spill is taking on birds and wildlife along the Louisiana coastline?
It’s hard to paint a picture because most of the toll is unseen. We’ve all seen the pictures of oiled pelicans and gulls. But most of the wildlife that are affected are just disappearing. We’ve only had 350 or so birds brought alive to the rescue [center] in Louisiana and yet many, many more must have been affected and just are not being rescued because they are not coming up from the oil.
Of course most of the oil is still in the water column and the largest toll is probably loss of fish and shrimp and crab. I spoke with a fisheries biologist who said that he fears that we could lose an entire generation of fish from this.
In other words the oil throughout the water column basically poisoning larvae and young fish?
There could be direct toxic effects, but there are also many bacteria and microorganisms that eat the oil. And in the presence of a lot of oil, those grow at a rapid rate, and they effectively suck all of the oxygen out of the water and make it too low-oxygen an environment for fish. We’ve seen some fish kills that are possibly related to the low oxygen conditions created by bacteria eating all this oil. So there are many, many different effects.
A pelican covered in oil is cleaned at the Fort Jackson Oiled Wildlife Rehabilitation Center in Buras, La.
So you’re concerned that in addition to the unknown hundreds, possibly even thousands, of pelicans and seabirds that may have perished or been affected, that the fish that they forage on could suffer great reductions in population?
Yes, that’s a big concern. We’ve been concerned about the indirect effects on birds to their food chain.
And if a bird was far off the coast, and say a pelican dove into an area where there was a fairly heavy concentration of oil, would that render the bird incapable of flying? And if so, how would that oil wind up killing the bird?
Birds that are farther out that fly into oil, many of those birds actually dive — gannets, frigate birds, sanderlings. Pelicans dive down into the water to catch their fish. You end up with additional effects besides just the oiling on the feathers. If the bird goes through the oil and the feathers get heavily oiled, the bird may be unable to take off and fly to get back to land to be rescued. But additionally, diving birds are diving through oil to catch fish that may be in oil, and those birds are very likely to ingest oil and that can cause kidney and liver failure. There are other internal toxic effects. So birds may die from the toxicity of the oil that they’ve ingested. If they come up and they are unable to fly away, because their feathers are coated, birds lose the ability to thermo-regulate or to maintain their own body temperature. If they’re in the water, even if it’s warm, they die of hypothermia — they freeze to death. If a bird makes it back to land and it’s very hot, birds can effectively bake. They can’t lower their body temperature — the feathers are the big insulating factor for birds. And impacting them with oil can cause the birds to either overheat or freeze.
What species are you most concerned about?
Well we’re obviously most concerned about species that have either declining populations or already have low population sizes. Obviously the brown pelican has become the poster child for this. It’s Louisiana’s state bird and has only recently, in November 2009, come off the Endangered Species List. There are birds that are right out there at
Protecting the shore and nesting habitat is not protecting birds that forage over water and dive into oil.”
ground zero where the oil first hit out on barrier islands and it’s hitting during their breeding season. So we’re very concerned about them. But there are many other birds that we’re also concerned about. Wilson’s plovers — one little beach that I know of in Louisiana holds 1 percent of the global population of Wilson’s plovers. If that beach gets hit with oil that’s a big problem. Overall the beaches in Louisiana hold 5 or more percent of the global population [of Wilson’s plovers]. We hate to see large impacts to Wilson’s plovers — adults being oiled, chicks not hatching just because of the disturbance of the protection [and cleanup] efforts that are out there.
We’re additionally concerned about all of the Audubon watch list species that are in the impact area, and that includes royal and sandwich terns. We’re very concerned about marsh species. Those are birds that will rarely be rescued. They’re in marsh grass and they’re secretive anyway and they’re much smaller than pelicans. Birds like mottled ducks, seaside sparrows, clapper rails — all will effectively just die and not be counted. For some of those birds, we don’t even have good ideas of what their population sizes were to start with. So they’re of grave concern, and they’re so secretive that they’re really not even being talked about.
I know you’ve been down in the wetlands a great deal in the last few weeks. Are you starting to actually see more oil coming into the marshes?
There’s been oil coming into the marshes. We see it and we are starting to see more because as the oil gets into the marshes it’s harder to clean out. You can’t pick it up. The marsh grass is fragile. You can’t put vehicles on the marsh to try to do anything because then you impact the marsh and cause it to erode. So when oil gets onto islands and sand, crews can go out and do some cleaning. When it gets into the marshes there aren’t as good cleaning techniques. And so once it’s in, it tends to be in and it gets harder for it to get back out.
When pelicans were taken off the Endangered Species List last year, what [were their] numbers [in Louisiana]?
There were 16,000 breeding adults in late summer in 2006, which was after Hurricane Katrina, but before Hurricanes Gustav and Ike. And those birds produced about 17,500 young. The birds were tending to increase over the last several years. So quite a good number of birds, many large colonies.
And if this spill continues to spread, could you see a very significant decrease in brown pelican numbers?
Yes, even if it’s kept off habitat. But the birds have to forage in the environment. The birds have to fly out. Brown pelicans need to make at least four feeding trips per day when their young are very young. And those birds can fly as far as 12 miles from their nest colony to forage for fish. So simply protecting the shore and the nesting habitat is not protecting the birds that forage out over the water. They still have to find places to fish, and if they dive into oil they are impacted and their chicks are impacted if those adults don’t return. But even if the oil stays well below the surface and the birds aren’t in it as much, if their food resources decrease, they will not be able to adequately feed young, and the young will starve, and the adult birds may start to starve. So there are many, many concerns about these birds and [other] birds that feed in similar ways — frigate birds, northern gannets, the terns that skim the water and plunge-dive for fish.
Do the brown pelicans along the Louisiana coast have chicks right now?
Yes, they’re in different stages of breeding. Some adults are still incubating eggs. Some are feeding young. There are young that are getting to be quite mature. The pelicans have a very prolonged nest cycle. They can start as early as late February or early March with breeding and there will
That was very difficult, knowing what was coming and that there was no way to warn the birds.”
still be young on some of these nesting islands as late as October. So many, many birds will be impacted and more birds will be impacted the longer we have oil in the environment. The longer this flows — they’re now talking about into August or later — we start to get ducks that breed up in the northern states and winter on the coast that will be moving in as early as late August. So we’re going to begin to be impacting entirely new suites of birds by late July or August as migrants start to come back through.
Do plunge-diving birds, when they see an oil sheen, will they try not to dive into it? It’s probably hard to see fish through the sheen, or are you finding that some of these diving and plunging birds are actually diving into the oil?
There are birds diving into the oil. I think that there’s been a lot of information that has shown that birds don’t necessarily have a great ability to distinguish between shiny water and shiny [oil] sheen. They don’t necessarily have reason to avoid what looks like oil. If they see fish where there’s oil, they’re just as likely to dive there as anywhere. Also, sometimes birds land on the water at night. There have been studies that have shown that they’ll land, you know, on oiled areas or even wet roads. So they’re not very well adapted to deal with this kind of threat.
Could you describe one or two of the more memorable or poignant scenes that you’ve witnessed?
The horrifying ones are the birds deeply covered in oil. Some of the more poignant scenes I think for me occurred early on when migratory shore birds like sanderlings and red knots were moving through. We would go out onto beaches to count birds, and you’d see tar balls starting to roll up and see these birds just running up and down the beach. Sanderlings are the little white shore birds that everybody is familiar with at the beach. They race in and out of the waves. And watching these birds race in and out of waves, watching terns dive into the waters that weren’t oiled yet, it was very sad just knowing that they have no idea what’s coming. There’s this lack of foreshadowing. They get no hints. They just go about their business and yet they’re in a danger zone and some of those birds would get lightly oiled, fly north to breed, and maybe either be too weak to breed or die on the migration. And, again, we know that we just never count those birds. That was for me very difficult, just the impact of knowing what was coming and knowing that there’s no way to warn the birds. To see all of these courtship and mating behaviors, to see birds on nests, to see young chicks, [yet] to know that their parent might have just been taken to the bird rescue center and while the parent may survive the washing and may be rescued, those babies that are waiting for mom to come back with food are going to continue to wait and to be in the hot sun with no food coming.
Once the birds are cleaned and rescued, what do you do about not putting them back in the same polluted environment from which you took them? Do you hold them in holding centers? What happens after they’re cleaned?
There are so many birds that are going to be impacted and many of them probably wouldn’t do well being held in captivity for a very long time. The idea really is to release them when they’re ready to be released. The [U.S.] Fish and Wildlife Service has been releasing a lot of birds on the east coast of Florida. But the problem with that is that it’s breeding season and the birds have a drive that’s been created over centuries to be in these habitats to raise their young. If adults were rescued off of nests with
It’s very difficult to see all these things and imagine what the birds are going through.”
dependent young, their instinct is to go back and try to feed their babies. So wherever you release them, they’re likely to fly back into the oil zone. The oil is coming in in different ways. It’s not necessarily that once an area gets oil that there will be oil throughout that area. We’re seeing strings and fingers of oil that break off and come into areas and then maybe are gone within a day or two. So it’s not practical, if you think about 16,000 adult pelicans and 17,000 young, that’s a lot of birds to try to capture, to feed, to house somewhere, and that’s just one species. And if you were to think about trying to save the birds, you add sandwich terns, royal terns, a million laughing gulls, Wilson’s plovers, the migrants, there’s no possibility of keeping the birds protected.
What we need to focus on is to try to maintain populations through improving and protecting habitats in other parts of the range where they’re not going to be oiled. So part of our focus with Audubon is not just at the individual bird level and the bird rescue, but what can we do to try to help improve habitats or create habitat and protect nesting success for birds in Texas, where oil is less likely to reach. How can we look at this range-wide for all of these species and try to put the resources in place so the birds that are not in the oil zone have the best chance of the best productivity?
I know you’ve been working for quite a while on the Audubon Louisiana Coastal Initiative and trying to improve the habitat that’s been denuded by the oil industry and the canals, [and other activity]. If this spill continues gushing into August and in comparatively large volumes, what sort of long-term impact do you see along the Gulf Coast in terms of bird life, and how quickly can bird populations bounce back from a large, ecosystem-wide trauma like this?
Obviously the longer oil spills and the more there is in the environment, the worse it is for all of the animals and the more it impacts birds. Populations, if they are at high enough levels, tend to be fairly resilient. It’s why we work so much in Audubon at the habitat level trying to make sure the habitats are there and healthy. Because birds intrinsically
We really are concerned about birds where the center of their range is at the center of the oil.”
try to find each other and mate and breed. If you have enough pairs they’re often able to come back from setbacks. We hope this is a setback and not a death sentence for any [species]. But again that depends a lot on just how long this goes and it’s variable by species. Even a species that we’re concerned about like the brown pelican, there are a lot more of those birds than there are Wilson’s plovers. The majority of population [of Wilson’s plovers] is in Louisiana and I think the second highest is Texas. We really are concerned about birds where the center of their range is at the center of the oil.
There are concerns that oil could kill the marsh grass. We don’t know how likely that is. The marshes are already disintegrating and deteriorating. We’re very concerned that any additional impact on habitat will negatively affect the ability of birds to come back from this type of setback.
Poor Louisiana and the creatures that inhabit it — you have had so many insults from the oil industry, damage from [Hurricane] Katrina, sometimes you must just shake your head and think, “My God, what did we do to deserve this?”
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There have been a lot of impacts on Louisiana, and I think something that’s really worth mentioning, too, is that a lot of human communities have been really negatively impacted. One of the reasons Audubon has always been focused on birds is intrinsically for the birds, but birds are [also] indicators of what we’re doing to our own environment. And fishing communities along the coast have completely lost their income. These are people who were just starting to recover from the hurricanes of two seasons ago. And losing that food base, a lot of Louisiana culture is based around food. People eat shrimp here several times a week, not once a month. These are daily foods, and to have these foods disappearing from market shelves, you start to lose not only your income from this, but you lose your community, you lose your culture. The birds are an indication of what we’re doing to ourselves.
Louisianans are really at the front lines and they need as much support as they can get, and a lot of that needs to come through people helping to push for good coastal restoration. It’s time to quit talking about it and to do it. [This spill] is an experiment, in a way, in total marsh loss. Losing the fishing, losing the shrimp this year, it’s an experiment in what happens if we don’t reverse some of the processes that have caused marsh to disappear.
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