The Washington Department of Ecology estimates that 66,000 to 100,000 fish have died in Olequa Creek near Winlock after a fire last week razed a warehouse nearby, potentially releasing more than a thousand gallons of vegetable oil into the creek.
The fish include juvenile salmonids, steelhead rainbow trout, coastal cutthroat trout, brook lamprey, sculpin, crayfish and red shiners. An estimated 94 percent of the dead fish were sculpin, a bottom-dwelling fish.
Ecology and the Department of Fish and Wildlife have not definitively determined a cause of death, but the die-offs are presumably related to the oil spill, because oil can coat fishes’ gills, causing them to suffocate. Oil can also cause an algae bloom, which deprives the water of oxygen.
Ecology spokesman Chase Gallagher estimated all aquatic animals in the creek, which is a tributary of the Cowlitz River, have died in a 3.5-mile area below the spill. Gallagher said there have been no reports that the oil sheen has reached the Cowlitz.
WDFW biologists were not available Monday to put the loss into perspective.
Officials still don’t know how much oil spilled into the creek, but the company that owns the warehouse, Olympic Trading Corp., was storing at least 1,100 gallons of vegetable and canola oil inside.
Ecology contract crews have been cleaning up the spill since the fire burned down the warehouse at 803 NW Kerron St. and disgorged the stored cooking oil.
“The absorbents are doing a good job,” Gallagher said of the pads the department is using to mop up the oil. “All the reports are saying that … the clearness of the creek is improving.”
An investigation into a cause of the fire is ongoing.