ATLANTA — A University of Georgia professor said she knows what is killing bald eagles in the state. It's a plant that shouldn't be here.
Georgia Department of Natural Resources officials have found 11 dead eagles at Lake Thurmond since October. A few others were discovered at other lakes and reservoirs around the state.
Tests show the eagles are contracting a rare disease called Avian Vacuolar Myelinopathy, or AVM.
"The eagles that are impaired with AVM have similar symptoms to someone who would be drunk," said UGA professor Dr. Susan Wilde. "Basically they're stumbling, they're having trouble flying."
Wilde has studied the issue for years. She's been able to link AVM to a plant called hydrilla. Like another well-known invasive plant, it came to Georgia from Asia.
"This is kudzu on the water," Wilde said. "It can reproduce from just a little fragment of it."
Hydrilla is very tough and dense. It can grow more than a foot a day, and fill a lake or reservoir in no time.
Dr. Wilde said a toxic algae grows on the hydrilla. Birds, like coots, eat the hydrilla and get sick. When eagles eat the sick coots, they die.
Dr. Wilde was the first person to discover the new species of algae that grows on hydrilla.
Officials in Henry County noticed hydrilla taking over one of the county's reservoirs. A short time later, they found a sick eagle, which later died. The county acted quickly and stocked the reservoir with another Asian import, sterile grass carp.
"We came up with the grass carp as the solution because it not only was cost effective, but it also was biologically sound," said naturalist supervisor Ken Presley with the Henry County Water Authority. "We knew we would not have to treat the reservoir with chemicals and that is what we really wanted."
Grass carp costs about $9 per fish. The county will know this summer, when hydrilla starts growing, if it is a success or if they'll need to stock again.
In the meantime, state officials are keeping a close eye on the grass carp experiment.
"This is a good test to see if the problem can be managed on a lake that size," said Jim Ozier with DNR. "Of course, that's a much smaller than a place like Lake Thurmond, which would be a much greater challenge and certainly more expensive."