Wichita Thousands of freshwater mussels, including specimens from eight at-risk species, were killed last week when the Kansas City Power & Light Co. pumped water from a river to replenish its cooling lake.
The mussel kill occurred when the KCP&L power plant at La Cygne in east-central Kansas pumped water from the Marais des Cygnes River near Pleasanton. The river almost ran dry.
Bruce Freske, Marais des Cygnes National Wildlife Refuge manager
When contacted, the KCPL plant's managers immediately stopped the pumping. By Saturday, the water in the Marais des Cygnes had slowly risen to what Freske thinks is a safe level.
Mussels are the most threatened animals in Kansas, with two-thirds of the state's 40 species at risk of disappearing. Biologists consider them important contributors to water quality because they filter out silt and pollution.
Mussel beds 5 miles downstream in the Marais des Cygnes National Wildlife Refuge in Linn County were left dry and dying, said Bruce Freske, refuge manager.
Freske estimated there were up to 2,000 dead mussels at the one large and three small beds he visited.
"With nine to 12 big beds ... there are undoubtedly many, many thousands dead when you start going up and down that 6 miles of river," he said.
KCPL, with headquarters in Kansas City , Mo., did not violate state or federal laws and will not face any penalties.
"What we want to do is try to save the mussels that are left," Freske said. "And we want to make sure this doesn't happen again."
Some of the mussels were able to move to deeper water.
"There were hundreds and hundreds of them, touching each other, with only an inch of water above them," Freske said.
That amount of water will not be enough to sustain them during the present heat wave.
Freske and Kansas wildlife officials have contacted the state's water office to see if water can be released from three upstream reservoirs - Melvern, Pomona and Hillsdale - to replenish the Marais des Cygnes flow. They're still awaiting word on whether that will be done, as it has been in the past.
"This is a major disaster for mussels," said Ken Brunson, supervisor for nongame programs for the Kansas Department of Wildlife and Parks. The state is investigating the mussel kill and will be assessing other impacts.
In the long term, Freske said, the refuge will closely monitor the flow gauges on the Marais des Cygnes to maintain enough depth for the mussels.
This mussel kill revealed two species thought not to exist any longer in Kansas. One purple pimpleback was found alive, and two were found that had recently died. Shells were also found of recently dead spectaclecase mussels.
Among the endangered and threatened species found in the kill were mucket and butterfly mussels, Freske said.