Zombie bass rose to the surface of Lake Wheeler in Alabama after biologists zapped them using electrofishing.

Researchers traveled in boats, applying an electric current to the water, which temporarily stunned the fish. The bass rose to the surface of the water, with their eyes and mouths wide open. After the zombie bass came to the surface stunned, they were gathered in nets, and transferred to an aerated holding tank, were they were kept safe. Each of the specimens was then measured and weighed. The animals were given a quick check to record general health, including possible parasite infestations. Bass recovered from the electric shock within a few minutes, and were released back into the wild, unharmed.

"By looking at the overall health and condition of the fish we collect we can tell a lot about what's going on with the fishery," John Justice, from the Tennessee Valley Authority (TVA), told the Associated Press. He was one of the researchers who participated in the study on Lake Wheeler. 

The TVA managed the study, which included nine marine biologists. The study will examine fish from around waters managed by the organization.

Fish are stunned in the water by a metal pole that hangs off a pair of fiberglass arms. Three metal cables, attached to the pole, are immersed in water. The cables are connected to an electrical generator aboard the boat. When power is applied to the system through a footswitch, six amps of electricity stuns the fish, and they float to the surface for collection.

Lake Wheeler stretches over 60 miles in northern Alabama, between Rogersville and Huntsville. The waterway is framed by Wheeler Dam on one side and Guntersville Dam on the other end.

These lakes are considered one of the most biologically diverse marine environments in the world. Over several years, data collected on the fish can help manage stocking efforts, as well as directing conservation efforts to protect endangered species.

Fish biologists insist electrofishing has no long-term effect on the health of the animal. Studies of fish used to involve directing the animals into a cove, sealing off the area, and killing the animals with a poison called rotenone.

People for the Ethical Treatment of Animals contends fish feel pain and it is opposed to the practice of electrofishing. 

Of the 200 or so fish examined at Lake Wheeler in this study, all survived the experience and were successfully returned to the water. 

Electrofishing in Vermont can be seen in action on YouTube.