Georgia biologists study small fish with big impacts on tiny waterways

Researchers in waders plod through a shallow streambed in North Georgia. 

Moving like a school of fish, they turn and pivot together, following the current downstream. One of the researchers, Robbie Ellwanger, is wearing a bulky, square backpack on top of his gray waders. 

Ellwanger, a biologist with the Georgia Department of Natural Resources, is shocking the pond — his backpack is sending small electrical signals down a pole into the water, stunning fish just long enough for Kaylee Blackburn to swoop them up with a net.