Unified command was formed to look in to the origin of the sheen, which did not seem to be expanding since it was first detected
Authorities in southern California are investigating a 2.5-mile (4km) long oil sheen that emerged off the coast of Huntington Beach on Thursday evening.
The sheen doesn’t appear to be a crude oil spill – it could be the result of natural seepage – and federal and state teams have deployed to the area to determine the source.