SCIENTISTS SEE LENGTHY RECOVERY

By CRAIG MEDRED
Daily News outdoors editor

ANCHORAGE- Nature could take a decade, maybe longer, to remove the last traces of North America's largest oil spill from the waters of primeval Prince William Sound, according to scientists who study oil spills.

"It will recover, but how and in what shape is the question," said researcher C. Peter McRoy of the Institute of Marine Science at the University of Alaska Fairbanks.

When the supertanker Torrey Canyon went ashore off England in 1968, the oil it spilled caused environmental havoc.

"That was the first big one, and they used some chemical dispersants that were highly toxic, much worse than the oil itself," McRoy said. Plant and animal life was wiped out. Their recovery was hampered by the fact the tanker was left to sit leaking oil into the English Channel for months.

"In this case, we're probably much better off," McRoy said. "It's not going to sit there and dump oil for the summer."

Scientists know that the 11 million gallons of oil that has spilled into the Sound is likely to kill thousands of birds and probably hundreds of marine mammals. But what they don't know is what it will do to the microorganisms, the invertebrates and the fish that make up more the vast majority of life there.

Where the oil coalesces into gooey tar and blankets the beaches, McRoy said everything that is covered will smother, and the oil will remain on the beach as an ugly black scar for years.

Over time, though, sediments will cover it, he said.

What will become of the portions of the crude that are dissolved in the water the so called water soluble hydrocarbons is harder to predict.

Where these chemicals concentrate, they will devastate the existing ecosystems, scientists said. But where they are diluted, the problems lessen.

"The question is always how to identify the humaninduced changes from the natural ones," McRoy said. "Some fraction of this (spill) will feed the microbes. Where that ends up in the food web, we're not sure."

The oil could prompt reproductive failures in some species and disrupt the biochemistry of others, McRoy said. Less certain is what happens to the microorganisms that form the base of the food chain and represent 50 percent of all life in the ocean.

Though invisible to the naked eye, they number about a million per milliliter of water, said Don Button, a microbiologist at the Institute of Marine Science.

Seawater teems with bacteria and the flagellates that graze on bacteria, he said. And some of these tiny life forms have the ability to consume oil, if they are not be consumed by it.

"If you get the concentrations high enough, you can just dissolve the cell membranes," Button said. "The bacteria dissolve in the oil."

At lesser concentrations, however, the bacteria feast.

"Some can (eat oil)," Button said. Others can quickly develop that capacity. These singlecelled microorganisms have the ability to undergo genetic mutations to become oil eaters.

"When they come into contact with it, they can turn on their latent capacity," Button said. "Some of it goes into the organism . . . and they make energy out of it."

Some of it, but not much, accumulates, and the rest is passed through as waste, Button said. Hydrocarbons, unlike complex molecules such as DDT, do not accumulate in the environment.

Bacteria can only eat the watersoluble hydrocarbons. The heavier hydrocarbons stick together in a tarlike goo that thickens every day. National Marine Fisheries Service biologist Steve Zimmerman said the crude is sloshing around in bays and coves, moving in and out with the tide, separating more and more by the day into watersoluble factions, and thicker and thicker tar.

Crude oil is made up a variety of hydrocarbons. These range from the extremely light and volatile molecules refined to create gasoline and toulene to the heavy molecules that make up asphalt and plastics.

Some of this goo could float around for years. A blanket of it has already formed on Naked Island, McRoy said.

Mopping it up, dissolving it or washing it off the beaches with highpressure hoses is virtually impossible, scientists said.

Man can't do anything to clean up the hydrocarbons that dissolve in the water. But the bacteria can. They break the oil down to get the carbon and oxygen out, and when the bacteria are eaten by flagellates, the carbon a basic building block of all life on earth moves on up the food chain, eventually feeding fish and birds.

For microorganisms, an oil spill might not be such a bad thing, but "nobody takes anything from a bacteria's point of view," Button said.

Of course, larger creatures have other problems with oil. Clams that live by filtering bacteria out of the water, for instance, also filter out some of the larger hydrocarbons, Button said.

These intervertebrates, and dozens of others, can suffer tissue or organ damage even death. So can fish.

"We need to set up a program to look at the longterm effects," McRoy said. "That is an opportunity, and we shouldn't waste it.

"This is like a major forest fire. It wipes out some of the existing (mix of) species. We'll see ecological succession, see pioneering, which has a whole new set of species in it."

Daily News reporter Charles Wohlforth contributed to this story.

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