"This stuff isn't changing at all. It's just the same kind of goo that got deposited there in 1989," said Jeff Short, a National Oceanic and Atmospheric researcher.

Litigation against Exxon Mobil Corp. by about 32,000 fishermen, Alaska natives, property owners and others continues in court.

The US 9th Circuit Court of Appeals will hear oral arguments on Friday over whether Exxon Mobil should pay a $5 billion punitive fine that the oil giant has been appealing for more than a decade.

"This is almost the end of the road. This will not be reviewed again. They'll pick the number and tell us what it is," predicted Dave Oesting, lead attorney for the plaintiffs.

Decisions in the 9th Circuit usually come weeks or months after the oral arguments. The appeals court has twice questioned the award, sending it back to the trial judge to reduce the fine.

US District Judge Russel Holland has twice sided with the plaintiffs, though he eventually reduced the amount to $4.5 billion. Accrued interest could bring the total amount to nearly $9 billion, Oesting said.

Exxon Mobil, the oil giant created from the merger of Exxon and Mobil in 1999, argues that the spill's effects have long receded and that the fine is unjustified.

The company points out that it spent more than $2 billion on the clean-up and shelled out $1.025 billion for a 1991 settlement with federal and state governments.

Exxon Mobil has argued in legal motions that the appeals court should reduce Holland's "outlandish judgment" to no more than $25 million.

ECOLOGICAL DEBATE

Along the coastline, debate about the spill's environmental effects continues.

According to the group that administers the settlement money paid by Exxon to the governments, only seven of 30 marine species, resources or services have recovered to pre-spill levels. Whether the spill is to blame and whether remnant oil is causing harm remains unsettled.

A scientist who has worked for Exxon says that even if there are isolated pockets of lingering oil, it is not getting into the food chain.

"Is it ecologically relevant? No," said David Page, the Bowdoin College biochemistry professor who has studied the spill on the company's behalf.

"To say that it's somehow causing damage when it's part of the baseline, that's not really scientifically correct," said Page, who added that natural oil that seeps along Alaska's coastline overshadows any lingering Valdez oil.

But Prince William Sound residents believe the spill triggered a cascade of environmental ills.

"As subsistence fishermen and hunters, we still see the effects of that oil spill just about daily," said Gary Kompkoff, head of the tribal council in Tatitlek, a tiny Native village just a few miles from the Exxon Valdez grounding site.