INDIANAPOLIS – Wildlife officials hoping to prevent Asian carp from slipping into the Great Lakes through Eagle Marsh chose a design Tuesday for a 10-foot-tall, chain-link fence intended to hold back the invasive fish.

Biologists fear the voracious carp, which can grow to 4 feet long and 100 pounds, could enter the Great Lakes and destroy their $7 billion-a-year fishing industry by starving out native species.

Indiana’s fence is designed to prevent adult carp from using the marsh to swim from the Wabash River system into the Maumee River – and then onto Lake Erie – in flood conditions, said Phil Bloom, a spokesman for the Indiana Department of Natural Resources.

Although smaller carp would be able to swim through the spaces in the chain-link fence, Bloom said that’s not a concern.

“Those small fish aren’t able to battle that kind of current at their young age, so we don’t expect them to be in that area,” he said.

The Wabash and Maumee river basins normally drain in opposite directions and have no direct link, but their waters can mix in the 700-acre marsh under certain flood conditions. DNR officials say that could let the Asian carp that have been present in the Wabash River system for nearly 15 years bridge the 20 miles between the Wabash system and the Maumee’s tributaries through Eagle Marsh. From there, they could swim to Lake Erie about 100 miles to the northeast.

Bloom said the fence will be built in a shape similar to a flattened “Z,” with two of the sides running parallel and the third middle section built perpendicular to the two other portions. He said that design is intended to allow floodwater to flow through the middle portion in case debris accumulates in the other two sections, obstructing the flow of water.

The marsh fencing will be a temporary barrier until a permanent system to keep the fish out of the Maumee River