The Montana Fish and Wildlife Commission recently approved an emergency regulation change that requires anglers to turn in any northern pike caught in Lake Mary Ronan.

Effective immediately, all northern pike caught must be killed immediately, kept and the entire fish submitted to Montana Fish, Wildlife & Parks. Anglers who catch northern pike in Lake Mary Ronan are required to report the catch to FWP within 24 hours by calling 406-752-5501. Anglers must turn in the whole northern pike to a FWP office within 10 days of capture. Edible portions of the fish may be returned to the angler upon request.

The regulation change is in response to the recent discovery of reproducing northern pike in the lake near Dayton.

FWP biologists are concerned that pike could impact the valuable kokanee salmon and trout fishery. The population density of northern pike is currently unknown, but FWP believes there is a high risk of population expansion in the lake.

The lake contains popular kokanee, largemouth bass, rainbow trout and yellow perch fisheries that would be negatively impacted by a sustaining northern pike population. Lake Mary Ronan is the sole source for eggs used for Kokanee aquaculture and stocking in the state. Pike are an extremely predacious gamefish that have impacted several lakes across the state due to unauthorized introductions.

Pike were first detected in Lake Mary Ronan in 2014. In 2018, an angler turned in a pike that was identified as the first confirmed reproduction of the fish in the lake.

Data collected from fish captured by anglers will help FWP further determine the source of the fish — reproduced in the lake or continued unauthorized introduction — and population size and viability.

“Lake Mary Ronan is a popular and high-quality fishery and Northern Pike pose a threat to that fishery,” said Kenneth Breidinger, FWP fisheries biologist. “We’re taking this very seriously and trying to learn as much as we can about the unauthorized introduction of pike to best inform our future management.”

Anyone who witnesses a fish and game violation, or property vandalism, anywhere in Montana can report the crime by calling 1-800-TIP-MONT (1-800-847-6668). Callers will remain anonymous and may be eligible for a cash reward.