When I parked on a hot, July day below the spillway at the Great Salt Plains Lake in northwest Oklahoma, I saw a motionless fisherman standing on the bank. He was holding his strung-up rod in one hand and scratching his head with the other.
In front of him along the rocky shore lay hundreds of white dead carp and drum, the stench overwhelming. When he turned and walked back to the parking lot, he hung his head as he passed me. “What a shame,” he said to no one in particular.
Another drought, another fish kill. This is not the first time there has been a fish kill at the Great Salt Plains Lake in Alfalfa County, which was the first water impoundment in Oklahoma, built in 1941 for flood control, water conservation, and recreation.
John Stahl, fisheries supervisor for the northwest Oklahoma region, is all-too used to this scenario. He has worked for the Oklahoma Department of Wildlife Conservation since 1979 and has seen fish kills numerous times at the Great Salt Plains Lake near Jay and Cherokee.
“The tailrace is a lot like a Pepsi bottle laid on its side,” Stahl said. “When the water level (table) goes down, whatever water is left pools up and the fish die.”
Fish only use approximately one-tenth of one percent of the available dissolved oxygen in the water. Bacteria use up the majority while breaking down organic matter.
The Great Salt Plains Lake has an average depth of only two feet, due to more than 70 years of silting and agricultural runoff. The shallower water warms faster which also depletes the oxygen.
The exceptionally hot summer of 2011 was so bad that all of the fish in the tailwater downstream nearly 100 miles to Ponca City died, Stahl said.
“The water (right below the lake) was so decomposed that it turned black,” Stahl said. “Even the turtles couldn't take it, so they climbed the banks and just died right there in the parking lot.”
Small gar were the only fish to survive last year, he said.
When the spring rains arrived, fish again migrated upstream to the dam and downstream into the lake from the two main tributaries, the Salt Fork of the Arkansas and Sand Creek.