The Washington State Department of Ecology, U.S. Coast Guard and a private cleanup contractor are responded to an oil spill reported Oct. 27 on Salmon Bay.

An unknown source, most likely one or more commercial vessels, released diesel fuel and hydraulic oil into the freshwater bay at Fishermen’s Terminal, on the southern shore, according tot he Department of Ecology.

This morning winds from the south pushed the oil north across the bay into a private marina on the north shore, according to the department.

An oil coating could be seen on the water’s surface in both locations, but it is too thin for cleanup in most areas, according to the department.

A cleanup contractor recovered oil from the water at the Ballard Mill Marina, north of Fishermen’s Terminal. Crews in boats and on the dock placed oil cleanup pads on the water.

Department of Ecology and Coast Guard investigators continued their efforts to identify the source of the spill. They found one fishing vessel which had a small release of hydraulic oil, but it may not account for all of oil in the bay, according to the Department of Ecology.

According to the department, the amount of oil is unknown. Tens of gallons can spread over the surface of an area the size of Salmon Bay.

All oil spills matter, regardless of size, as petroleum products are toxic to the environment, according to the department.