Fish kill remains mystery
CENTRAL POINT — Biologists suspect they may never identify the toxic substance, or its source, that killed dozens of juvenile salmon and steelhead in lower Griffin Creek late last week, authorities said.
The dead fish, first discovered Sunday, included wild coho salmon, a species classified as threatened under the federal Endangered Species Act, making the fish kill possibly a federal crime, authorities said.
The dead fish were located in about a one-mile reach between Highway 99 and Interstate 5, near where the stream flows into Bear Creek.
After a week of chasing tips, the Oregon Department of Fish and Wildlife and the Oregon State Police investigation into the cause has come up dry.
"So far, we haven't found anything that seemed like it could have caused the fish kill," said David Haight, an ODFW fish biologist in Central Point.
And short of a smoking-gun tip, the cause may remain undiscovered, Haight said.
"It would be pretty tough to trace it back to a particular source," Haight said.
"It could be someone spraying herbicide in flowing water or someone dumping something down a storm drain."
Even small doses of pesticides can be highly toxic in the aquatic environment and can trigger a fish kill, Haight said.
"Storm drains also aren't something to dump stuff," he said. "For the most part, they go right to the nearest stream."
OSP Sgt. Kirk Meyer said the case remained open.
"Hopefully, we can get a tip on it," he said.
Among the dead fish was one confirmed wild coho yearling. Another 40 fish were suspected as being wild coho fry about 11/2 inches long that recently hatched from creek gravel, but their identity was not confirmed because the fish were so decomposed.
Wild coho in Southern Oregon and Northern California — including the entire Rogue River Basin — were listed as threatened under the ESA in 1996.
Harming or harassing wild coho without federal permission is illegal under the act.
Also discovered among the dead fish were 320 red-sided shiners, which are a non-native species, and juvenile wild steelhead, most of which were about 4 inches long. They included a 6-inch pre-smolt, he said.
Haight said biologists inspected the gills of the dead fish to look for burning associated with chemicals. The fish, however, were too decomposed to reveal any clues, Haight said.
Rogue Valley Sewer Services also inspected some of its drains but found no clues for the investigation, Haight said.
The dead fish were discovered by a nearby resident Sunday along the stretch of creek that flows past Crater High School and the OSP's district office along Highway 99.
Reach reporter Mark Freeman at 776-4470, or e-mail firstname.lastname@example.org.