Paddlefish Dying in Lower Ohio River
Frankfort, KY – Paddlefish in the lower Ohio River between Smithland Lock and Dam near Smithland, Kentucky and Uniontown (J.T. Myers) Lock and Dam just upstream of the mouth of Wabash River are dying from unknown causes. Several hundred dead paddlefish have been reported dead.
“We’ve seen consecutive weeks of high water temperatures with low and clear water which indicates low zooplankton levels,” said Gerry Buynak, assistant director of fisheries for the Kentucky Department of Fish and Wildlife Resources (KDFWR). “Aquatic nuisance species including silver and big head carp along with zebra mussels are in the river. All these animals feed on zooplankton and compounds the competition because paddlefish only eat zooplankton.”
The fisheries division received reports of increased numbers of zebra mussels in the lower Ohio River this year. More zebra mussels in the river place greater stress on the zooplankton population during a time of year when zooplankton numbers are typically low. Zebra mussels have impacted several northern lakes by their density and filtering capacity.
“The heat combined with low flows causes these poor environmental conditions,” Buynak said. “The river is 86 to 87 degrees from top to bottom and we had an employee take a surface water temperature of 94 degrees at a boat ramp in the lower pool of the river recently.”
These stressors appear to be impacting the paddlefish. “Fish live in a stressful environment all of time,” said Mike Hardin, head of the environmental section of the fisheries division for the KDFWR. “When we have conditions like this, it is just too much.”
Officials ruled out poor water quality as an issue in the paddlefish deaths after testing the lower Ohio River for ammonia levels, acidity, dissolved oxygen and the level of nitrites. All tests came back in the acceptable range. Officials also are currently looking at disease as a possible cause of the paddlefish deaths.
”We took a paddlefish to Kentucky State University to look for disease and its spleen was swollen, its gall bladder was full and the only thing in its stomach was algae,” Hardin explained. “All indicators show they are not eating. This is for the entire Smithland Pool of the river.”
The fisheries division also received reports of dead paddlefish in the Wabash River in Indiana. Tissue samples were sent to Auburn University to screen for viruses while water samples were sent to Murray State University to rule out toxic effects from blue/green algae.
“The lack of food and the stress of the environmental conditions are causing them not to eat,” Hardin said. “It is hard to tell which one is leading to the other.”
Monitoring will continue, but a significant change is not expected until a good rainfall increases flow in the river.
The Kentucky Department of Fish and Wildlife Resources (KDFWR) manages, regulates, enforces and promotes responsible use of all fish and wildlife species, their habitats, public wildlife areas and waterways for the benefit of those resources and for public enjoyment. KDFWR, an agency of the Commerce Cabinet, has an economic impact to the state of $4.8 billion annually. For more information on KDFWR, visit our web site at fw.ky.gov.