"There has been sheening oil that has contaminated some birds, but we think the scope of the damage is less than indicated," Coast Guard Capt. Mike Hall said Thursday as crews prepared to tow the ship's beached, broken bow back out into deep water for a second time.
Hall said initial reports of environmental disaster were premature, and he even hinted they might have been a hoax, reports CBS affiliate KOIN.
Still, there were scattered tar balls along 23 miles of beach. A petroleum sheen was tracked into nearby Alsea Bay, famous for its salmon and crabs and home to bald eagles, peregrine falcons and marbled murrelets.
Federal wildlife officials who checked 11 miles around the wreck found 278 oiled shorebirds. Seven were dead. Roy Lowe, a biologist with the U.S. Fish and Wildlife Service, said half of all the sanderling flocks seen skittering through the surf were splotched with oil.
Crews observed some clean birds, including a bald eagle, but they were ingesting oil by feasting on the carcasses of dead birds.
Bill Milwee, salvage consultant to the ship's Japanese owners, said crews hoped to rig a new 14-inch-thick tow rope and use a single tug to pull the ship back out to sea by Sunday, when a small storm is expected to hit.
"We don't want to be caught with this thing on the beach in a storm," he said. "That could drive it well up on the beach and make it untowable."
Coast Guard Cmdr. Paul Jewell said the 420-foot bow section still holds as many as 130,000 gallons of heavy bunker fuel but the oil is contained in the hull and isn't leaking.
Jewell displayed cups of oil brought from the spill and turned them upside down to demonstrate to reporters that the oil was too thick to pour.
State agriculture officials warned against harvesting mussels or clams along a seven-mile stretch of beach surrounding Alsea Bay. Bait shrimp fishing was closed to keep boats out the area.
The New Carissa, with 400,000 gallons of fuel, ran aground Feb. 4 in a storm at Coos Bay, 80 miles south of Waldport.
It was set afire before it broke in two and spilled 70,000 gallons of oil. The stern is still mired in the sand near Coos Bay, where oyster and shellfish harvests are open again.
The bow section was being towed for a burial at sea this week when a storm 50 miles out in the Pacific ripped it loose from its towline and cast it adrift, sending it nose first into the beach at Waldport.
Tar balls began showing up almost immediately, and by Thursday afternoon 185 people with rain slickers, shovels and plastic bags scoured the beach to pick up the pollution and lay out absorbent pompoms near the surf line.
Oil has been found on beaches as far as 100 miles north, but officials were testing to detrmine whether it came from the New Carissa.