The ship was a container ship not an oil tanker. The fuel tank was breached, hence the spill.
A guy who called in to Levin’s radio show claimed it was a Chinese container ship and that the California press was burying that lead story. He was extremely mad and said the Chinese were not happy enough trying to poison our kids with lead painted toys, now they were polluting our water. He seemed very upset that Pelosi was cracking down on the Coast Guard guys but ignoring the crappy Chinese shipping company that was the real culprit.