Hundreds of fish began to mysteriously turn up dead at Okatibbee Lake last week. However, poisoning has been all but ruled out as the cause.
Corps manager Jack Huntley said 93 percent of the fish that have been affected were white perch, or crappie.
"Since it's species specific to just the crappie, we feel like there's probably not a poison involved," said Huntley.
Tests indicated no problem with the safety of the water, but Huntley said it's possible that, if oxygen levels in the water dropped extremely rapidly, that could be responsible for the large number of dead fish.
The Mississippi Department of Wildlife and Fisheries and the Mississippi Department of Environmental Quality have been called on to help determine what happened.