Two northern pike recently caught at Crooked Lake near Columbia City are raising concerns among officials at the state Department of Natural Resources.

The predatory fish may harm the lake’s fragile cisco population, said Jed Pearson, who works for the DNR Division of Fish and Wildlife.

It marked the third time in four years that pike – 27 and 29 inches long in this case – have been detected in the 206-acre natural lake. The discovery was made during general fishery surveys conducted by the DNR, Pearson said.

The most logical explanation, Pearson said, is that people are catching fish in one lake and releasing them in another in hopes of populating the water with a specific breed.

State law prohibits catching fish in one lake and releasing them in another lake without an approved permit.

Those found in violation can be charged with a Class C misdemeanor, punishable by up to 60 days in jail and up to $500 in fines, he said.

“Pike is a popular fish that people like to catch,” Pearson said.

The problem is that pike – which can grow more than 3 feet long – are predatory and typically prey on suckers, perch and ciscoes.

A close relative to trout and salmon, the cisco fish has seen a drastic decline in numbers, Pearson said. Only 13 Indiana lakes still contain ciscoes, down from more than 40 lakes in the 1950s.

Crooked Lake still contains a large cisco population, but before 2009, no northern pike were known to exist in the lake. Five pike have since been found, including the two caught recently.

DNR officials see the same problem with white bass, another predatory fish that has been showing up in northeast Indiana lakes, Pearson said.

Pearson admits it’s “awfully hard” to catch someone in the act of releasing fish into another body of water, but DNR officials are on the lookout and will continue to monitor the fish through the surveys, he said.

Although finding two pike in the lake does not seem like a major problem, Pearson said, the danger is that the fish may reproduce, becoming dominant cisco predators and competing with other fish for food.

Biologists say it is too early to tell if pike are spawning in the lake. They won’t know until they begin to catch small, young pike.

vsade@jg.net