State officials continue to investigate a near-total fish kill in Gasper River that occurred over Memorial Day weekend.
On May 28, the Kentucky Division of Water recorded dissolved oxygen levels of 2 milligrams per liter in water samples collected along Gasper River and Clear Fork Creek.
This week, the water samples revealed a new clue.
“The samples we have received thus far have turned up levels of nutrients and E. coli,” John Mura, communications director for the Kentucky Energy and Environment Cabinet, said in an email. “We have partial results in, but they are not enough for us to say conclusively what caused the fish kill. We are still investigating.”
Decreased oxygen concentrations typically indicate the presence of bacteria or nutrients, often from untreated sewage, fertilizer runoff or manure. E. coli is most commonly found in cattle farms where the bacteria can live in the intestines of healthy cattle, according to the Centers for Disease Control and Prevention.
“It could be animal waste, it could be fertilizer. It’s something that’s using oxygen to break down,” said Eric Cummins, the local fisheries biologist for the Kentucky Department for Fish and Wildlife Resources, who has been helping document the fish loss.
Through his investigation, he concluded the fish kill originated in Clear Fork Creek, near where the creek and Gasper River meet about five miles south – upstream – of where the Jackson Bridge Road crosses the Gasper River.
“A good part of Clear Fork is in degraded condition,” Cummins said.
About a mile downstream of the Jackson Bridge Road crossing, at the Gasper River Retreat, there were numerous live fish “in good proportions,” so the dissolved oxygen levels “probably petered out a little above there” thanks to riffles (shallow areas) where the water could “pick up some oxygen” to retain concentrations high enough to sustain aquatic life, Cummins said.
David Haydon, a Bowling Green resident who owns a river-adjacent property on Hammett Hill Road, noticed the dead fish during the Memorial Day holiday. He suspected that the lack of a buffer zone from a nearby Warren County cattle farm could be a likely cause.
But the officials continue to investigate potential sources of the contamination.
“There are multiple inputs. It’s hard to say,” Cummins said.
Last week, Cummins returned to Gasper River to the dead fish zone. He observed near-normal oxygen levels, and some live fish that migrated back into the five-mile fish kill stretch.
Flooding and inputs from other feeder creeks could help the recovery process, but fish spawning will take time. Next summer, a fish spawn could return a moderate level of fish, but it could take years before the area fully recovers to the level it was before the fish kill.
“For people that live in that five-mile section, it’ll still take a little while for them to see fish numbers back to what they had been accustomed to in recent years,” Cummins said.