FISHING -- Testing has confirmed that two walleye caught in western Montana's Swan Lake last fall were illegally transplanted and not spawned there, state wildlife officials say, and they're not happy about it.

Fish, Wildlife and Parks biologists say microchemistry analysis of the inner ear bones of fish indicates they were introduced to the lake sometime last year.

A fish’s inner ear bone incorporates the chemical makeup of the water as it grows. Biologists are analyzing fish from other areas to determine the origin of the transplanted walleyes.

If walleyes established a breeding population in Swan Lake, the predatory fish could damage the lake’s population of kokanee salmon and bull trout, which are classified as threatened.

The reward for information leading to the conviction of whoever is responsible for the illegal introduction is up to $30,000.

Last year, the state agency announced it was fed up with the costly consequences of selfish anglers who illegally transport and introduce fish, especially walleye, into state waters.