The dead fish Hendersonians are seeing floating in the Ohio River—and decomposing on its banks—is a result of higher water temperatures that can’t hold as much dissolved oxygen, say biologists with the Kentucky Department of Fish and Wildlife Resources.
In a message sent to the Hendersonian, the KDFWR said the “most likely cause of these fish mortalities is low dissolved oxygen.” The message added that low dissolved oxygen in the water occurs because of higher temperatures, sunny days and an increased oxygen demand by many other aquatic organisms.
The KDFWR said that in addition to fish needs for oxygen during summer nights, there is also an increase in need from plants, bacteria and algae during the night which “drastically lowers the amount of oxygen in the water.”
Invasive carp die-offs have been noticeable recently and the past several years, according to KDFWR, because they are large fish and there is a large number of invasive carp in the Ohio River.
