An estimated 100,000 dead drum fish are floating along a 20-mile stretch of the Arkansas River and washing up on the river's banks near the town of Ozark in the northwestern part of the state.
The dead fish were discovered just after 3,000 red-wing blackbirds fell from the sky in the town of Beebe, more than 100 miles from the site of the dead fish. Officials, who tripled the early estimates of the number of dead birds, said the bird deaths may have been caused by lightning or by stress from fireworks and said they were unrelated to the fish kill.
Fish kills happen every year, but kills of this size are relatively rare. Hundreds more drum fish are sick and have been sent to the University of Arkansas for testing.
Andrew Goodwin, the associate director of the University of Arkansas' Aquaculture and Fisheries Center, said he didn't believe the deaths were caused by pollutants. "It's unlikely to be a toxin," Goodwin told AOL News by phone today.
Instead, Goodwin said he suspected that the drum fish may have experienced a population boom this summer that created more competition for food and sapped the weaker ones of their ability to fight off disease.
"It's your classic boom and bust," he said. "A group of fish will go into a population boom, and then they're competing for food, so they may not be in really good condition. Then during a cold snap the environment changes with the temperature, and their immune systems are compromised and can't always fight infection."
Authorities said only drum fish seem to have been affected, making it even more unlikely that a pollutant is to blame.
"The fish kill only affected one species of fish," Keith Stephens of the Arkansas Game and Fish Commission told CNN. "If it was from a pollutant, it would have affected all of the fish, not just drum fish."
The commission did not immediately respond to a request for comment this morning. Authorities are warning residents near the river to not eat the dead fish.