Research by a Warnell faculty member has unlocked one piece of a puzzle plaguing man-made lakes in the Southeast—although why it is so deadly is still a mystery.
For the past 25 years, American bald eagles along with thousands of water birds have been killed by a new kind of cyanobacteria that produces a lethal toxin. Scientists had a name, Avian Vacuolar Myelinopathy, and they saw patterns—specifically, that birds were dying at man-made lakes.
Then, reports the Athens Banner-Herald, Susan Wilde, a professor of aquatic science at the University of Georgia Warnell School of Forestry and Natural Resources, discovered a previously unknown kind of cyanobacteria growing on the underside of hydrilla leaves, a plant known for growing fast and furious on man-made lakes and reservoirs in Georgia.
Water birds called coots ate the hydrillas, and then eagles ate the coots, who became disabled through the bacteria. The effects of the bacteria were the same in all affected birds, though: It caused lesions throughout their brains that made them look like sponges.
That discovery was made in 2014, and since then scientists have discovered the toxin can cause Avian Vacuolar Myelinopathy in more animals than just coots and eagles, but now lake managers are trying strategies to beat back the hydrilla growth, including stocking lakes with grass-eating carp and using chemicals on the plants—which carries another set of risks.