SAN FRANCISCO (AP) _ Quarter-sized globs of oil washed up on beaches Sunday as a Coast Guard investigator examining a mysterious oil slick that hurt more than 300 birds reported two new patches in the Pacific Ocean.

The first slick, measuring 15 yards wide and nearly two miles long, was discovered Saturday about 13 miles west of Point Ano Nuevo and 25 miles south of San Francisco, said Coast Guard Lt. j.g. Patrick Trapp.

''All they found was a slick of oil with nothing else around it,'' he said.

An investigator from the Coast Guard's marine safety office was flown to the site by helicopter Sunday reported spotting two new slicks, while the first one appeared to be eroding, Trapp said.

One of the new spills was near Pescadero Point, about 20 miles south of San Francisco, he said. The second was 200 years in diameter about eight miles west of the Golden Gate Bridge.

The slicks could have been caused by a ship pumping out its bilges before moving on along the Pacific Coast, he said, ''and hours later it's nowhere in sight.''

''The marine safety office feels they have a lead on a ship that was allowed to go out at that general time,'' Trapp said. Analysis of oil samples could help confirm whether the ship created the slicks.

It is illegal to dump anything overboard within three miles of shore, said Coast Guard Lt. Steve Boyle. More than three miles off the coast, he said, it is legal to dump highly diluted waste from oil tanks or bilges.

At the Peninsula Humane Society, volunteers were called in to help rescue more than 200 oil-coated common murres, loons and grebes that had washed up on a 90-mile stretch of beaches, said wildlife service manager Sandi Stadler.

''It's just awful,'' she said. ''They are covered. There are hardly any of them that have just a speckle.''

The Coast Guard said Sunday more than 300 birds were injured by the oil.

''There was one woman I saw who took off a beautiful white sweater and gathered a bird up in it,'' said state humane officer Kathryn Olson. ''I mean, forget the sweater after that.''