The U.S. Coast Guard and the state Department of Ecology (DOE) are investigating a quarter-mile-long oil sheen reported yesterday morning west of Vashon Island and north of Point Richmond on the Kitsap Peninsula.

Pollution investigators determined the oil could not be recovered, according to the Coast Guard. It was first reported at 8:22 a.m. on the west side of Colvos Passage in Puget Sound, and it later dissipated.

Pierce County fire crews initially responded to the report.

Anyone with information about the sheen is asked to call DOE at 360-407-6300.