DRAKESVILLE — An increase in a certain species of fish is prompting concerns at Lake Wapello State Park.

Recently, the Iowa Department of Natural Resources and park rangers out at the park have noticed an increase in Gizzard Shad in the lake.

Park Manager Ron Moore said Gizzard Shad are a species of fish that repopulate rapidly and take control of their environment.

“The other fish feed on them,” he said. “But once [the shad] start outnumbering the other species of marine life, it starts taking an effect.”

Moore said the projected overpopulation would cause a stunt in growth of the other fish in the lake and eventually ruin the fishing at Lake Wapello.

“We are hoping we can control the Gizzard Shad population and handle the situation, but if not, we might have to revert to some other methods,” he said.

One method would be to drain the lake.

If the species starts to populate too rapidly and take over the lake, Moore said they will be forced to drain the lake completely.

“If we don’t control it, they could double and triple in population in the matter of a year,” he said.

To help control the population, anglers are also prohibited from using live bait in the lake.

“It’s actually illegal to use live bait in a lake fishing area anyhow,” Moore said.

If the problem persists or continues to worsen, draining the lake would likely take place in the next five to seven years.

“That will be up to our fish biologist at Lake Rathbun,” Moore said.

“They’re just another species of fish, but they repopulate so fast that it hurts the lake environment,” he said. “It’s not a problem yet, but it could become one.”

Scott Niles can be reached at (641) 683-5360 or via e-mail at sjniles@mchsi.com.