Crown Memorial State Beach in Alameda is hardest hit by the spill.The current estimate of the size of the spill is 400-800 gallons.
Tar balls - some the size of silver dollars and a few as big as seat cushions - have washed up along shore every five to 10 yards. About 60 oiled birds, about half dead, were found at that site.
In addition to tar balls along Crown Memorial Beach, oil was washing up in the Ballena Isle Marina in Alameda, Coast Guard officials said.
The California Department of Fish and Game banned shoreline fishing and shellfish harvesting until state health officials could evaluate any contamination caused by the spill.