Lindsey Konkel, truthout
J.Strom Thurmond Lake, Georgia – From their perch in a loblolly pine, two bald eagles swoop low over a floating flock of wintering coots.
Most of the water birds scatter, but a few are left struggling on the surface. They flail on their backs, their wings twitching. They sense danger, but they cannot flee. Choosing its prey, an eagle dives over one of the sick coots, skewering it with sharp talons.
A mysterious toxin – with no name and no cure – lurking in lakes in the South has drilled holes in the brains of these waterbirds, rendering them unable to swim, eat and fly. In turn, this poison likely will also destroy the brain of the eagle that ate the coot.
Lacy holes that look like soap bubbles dot the tightly knit meshwork of the coots’ brain tissues, blocking the neurological signals transmitted between regions of their brains.
Since avian vacuolar myelinopathy, or AVM, was discovered in 1994, 76 dead eagles and hundreds of coots and other water birds at Thurmond Lake alone have been attributed to the disease. The full toll is unknown, but thousands of dead ducks, geese and even an owl have been recovered at 19 lakes across six states: Georgia, the Carolinas, Arkansas, Texas and Florida.
Researchers have found that the poison is attached to a newly discovered type of blue-green algae that grows on ubiquitous, invasive waterweeds.
“It may be an indicator of a larger ecological problem in which birds are the sentinels,” said Dr. John Fischer, director of the Southeast Cooperative Wildlife Disease Study in Athens, Ga.
In humans, researchers suspect that a neurotoxin may be linked to Lou Gehrig’s disease, or amyotrophic lateral sclerosis (ALS), a lethal neurodegenerative disease that destroys parts of the brain. No one knows whether any human neurological diseases are related to the bird disease, but new clues about the poisoned birds are emerging.