‘Mystery sheen’ off Shishmaref coast returns, identified as fuel mixture

A gasoline sheen along the Shishmaref shoreline. (Photo: Alaska Department of Environmental Conservation)
A gasoline sheen along the Shishmaref shoreline. (Photo: Alaska Department of Environmental Conservation)

An oil spill of unknown origin is for the third time in the last year seeping off of Shishmaref’s western coast, but now the state Department of Environmental Conservation says they may have identified the source.

The oily sheen was first discovered last June, on the northern coast of Sarichef Island along the Chukchi Sea. Shishmaref’s Village Public Safety Officer first found the sheen on the nearshore icepack and said at the time it smelled like gasoline.

State DEC and the U.S. Coast Guard officials responded to investigate—and begin cleanup efforts—removing 30 bags of oily waste and recovering about 100 gallons of the fuel-like substance. But the sheen reappeared in December, and even after additional cleanup efforts, exactly what kind of petroleum substance—and where it ultimately came from—remained unknown.

Samples of the sheen, as well as from community’s fuel tanks, were collected from both the June and December visits and tested at the U.S. Coast Guard’s Marine Safety Lab in Connecticut.

On May 26, the sheen returned, and again the community VPSO called it in, again noting a gasoline odor.

Now DEC officials say an analysis of those samples reveal the substance is a mix of “weathered gasoline and diesel.” During a site visit on Thursday, June 4, DEC and Coast Guard accessed an area along the shoreline identified as the “outlet” of the sheen’s seepage. A release from DEC says responders also observed the oily sheen on gravel that was visibly stained by gasoline.

Just how much of the gas and diesel has been released is unknown. Responders say cleanup is ongoing. So far, officials say only the land and water around the Shishmaref Native Store has been impacted. As of the visit this month there have been no reports of affected wildlife as a result of the sheen.