Tom Moorman is director of conservation planning for Ducks Unlimited Southern Region. In the interview below, he underscores the threat posed to ducks and other birds, as well as marine life and coastal wetlands, by the Gulf oil disaster. The region is recognized as one of the world's most fragile, and threatened, ecosystems.

Q What's the latest on the oil gushing into the Gulf?

A The spill is estimated at about 200,000 gallons a day, and has not been capped. As of this evening [Monday], the oil hasn't made landfall in coastal Louisiana, which is good news given the onshore winds we've had.

Is it possible to control the spread of the oil with the booms that are being laid on the ocean surface?

They can block it under the right circumstances. But if the wind blows and the seas get rough, waves can overtop them. Also, they can wash ashore. If the weather is fair and seas are calm, I think they can protect the highest-priority areas, at least for a little while. But if this thing goes on for weeks or months, it's problematic.

Q How is Ducks Unlimited reacting to the threat the spill poses to the fragile coastal wetlands of Louisiana and Mississippi, and to the nearly countless bird and wildlife sanctuaries along the Gulf Coast?

A We've been concerned about the Gulf Coast, particularly its coastal wetlands, for a long time. This region has been in an ongoing ecological crisis, losing about 20,000 wetland acres a year. About 4.7 million ducks have wintered in the Mississippi River coastal marshes of southeastern Louisiana historically, a number that varies annually. The region is one of DU's top five international conservation priorities.

The spill has real potential to exacerbate that. If the oil comes onshore into the marsh and coats the vegetation, killing it, the soils become exposed and erode, and the rate of land loss accelerates. What's important are not only the coastal wetlands, but the marshy lands surrounding them, in which there are freshwater ponds used by waterfowl. This is very important wintering duck habitat.

Which resident ducks are threatened?

A Mottled ducks, which right now are brood-rearing. They would be at risk if oil comes into the fresh and brackish marshes. For this to occur, the oil would have to get through the salt marshes and spread into interior freshwater and intermediate salinity marshes.

Q Which species of wintering ducks are at risk if the oil washes up into the salt, brackish and freshwater marshes and ponds?

A First, it's really fortunate this didn't occur in winter, because of the number of birds that are attracted to that area then.

In the area most at risk of oil contamination, anywhere from 1 million to 2 million lesser scaup [bluebills] may spend the winter. About half that number uses offshore habitats, where the oil is. This would have been a catastrophe.

Likewise, canvasbacks and redheads would be threatened had this occurred in winter, and could be in the upcoming winter. Around 15,000 to 25,000 canvasbacks, for instance, spend the winter in wetlands at the mouth of the Mississippi, directly in the path of the oil. Additionally, we've had about 25,000 redheads winter on the shoal grass flats associated with the Chandeleur Islands which also are in the path of the oil.

In the interior marshes, gadwalls are probably the most abundant birds. Also, green-winged teal and blue-winged teal are fairly abundant. And lots of pintails pass the winter south of Venice, which is near where the oil is. American wigeon are also fairly common down there. And during some years, so are mallards.

Q The marshes also provide a nursery for crustaceans and fish.

A Yes, about 20 percent of the nation's commercial seafood originates in coastal Louisiana. These include brown shrimp, blue crab, oysters and various fish. Vulnerable as well is the region's vast recreational fishery, including species such as speckled trout and redfish.

Q Do the wetlands and marshes provide spawning habitat for these fish?

A Various habitats are threatened. You have to make assumptions where the oil would go; the threats vary as you do. If the oil goes into the salt or brackish marshes, that's where young redfish stay until they mature. Speckled trout do the same thing. So it's a nursery for pre-adult fish. So if these habitats are lost and not quickly restored, these nurseries would be at risk.

Q What's the best-case scenario?

A That they get the well capped, and quickly, and that the oil itself stays offshore where it can be skimmed, cleaned or, if necessary, burned off. That has toxicological issues also, but it would prevent the oil from coming on shore. But the best-case scenario is pretty unlikely. The oil slick is growing so fast, and this time of year the prevailing winds down here are from the south and southeast.

Q The worst case?

A If it gets into the marshes in a paint-like consistency, the vegetation can be killed. Those plants serve a lot of functions. They hold the soil in place. If the vegetation dies, the root mass degenerates and the soil is exposed to wind and wave action, and eventually erodes. In that case, the marsh land and associated marsh ponds that support wintering waterfowl would be lost. Those kinds of losses are and were occurring at a rate of about 20,000 acres annually. The spill could accelerate those losses.

Q How can DU and other groups effectively respond?

A We simply have to ramp up and restore as much of the wetlands as we can and continue to advocate for changes in public policies regarding how the Mississippi River is managed. The Mississippi needs to be more broadly diverted in a managed way to infuse freshwater and sediment into the marsh, which will help restore the wetlands. The Corps of Engineers will have to do it. With a host of partners, we've long advocated this.

Dennis Anderson •