Radio messages recorded the morning the Exxon Valdez ran aground show the ship's captain spent up to an hour trying to rock the tanker free, a move the Coast Guard says could have sunk the ship.

The transcripts were obtained in a Freedom of Information Act request by the Anchorage Daily News, which published details Tuesday.Also Tuesday, Exxon Corp. said 31 lawsuits and 1,300 claims ranging from $500 to $4 million have been filed against the company in the wake of the 10.1 million gallon spill of oil from the Valdez. At a meeting of security analysts in New York, Exxon officials declined to put a total value on the lawsuits or the claims.

In other developments, millions of tiny salmon have been released into oil-tainted Prince William Sound, and wildlife officials were deploying fireworks, shotguns and other noisemakers to scare migrating birds to safety.

Transcripts of March 24 radio messages between Coast Guard Commander Steve McCall and tanker captain Joseph Hazelwood indicate the skipper tried to free the ship despite warnings the tanker might be unstable.

In the first transmission, Hazelwood informed the Coast Guard in Valdez that he was aground, "leaking some oil and we're going to be here for a while."

The ship's logs indicate the ship ran aground on Bligh Reef some 23 minutes earlier. The delay in reporting and Hazelwood's position report are subjects of an investigation.

McCall was rousted from bed to deal with the crisis and contacted Hazelwood for a situation report.

"We`re working our way off the reef," Hazelwood said. "We've, ah, the vessel has been holed and we're ascertaining, right now we're trying just to get her off the reef and we'll get back to you as soon as we can."

McCall told Hazelwood to take it "slow and easy," and said help was on the way.

"Before you make any drastic attempt to get away, make sure you don't, you know, start doing any ripping," McCall said. "You got a rising tide . . . I wouldn't recommend doing much wiggling."

A conversation about 1 1/2 hours after the first transmission indicated the Exxon Valdez's engines had stopped and apparently the effort to free the tanker had halted as well.

There was no immediate indication whether trying to free the ship made the problem worse.