The Shields River has become infested with Smallmouth Bass. Montana Officials have now made regulations that anglers must kill, report, and turn in all smallmouth bass caught in the Shields River. Recent angler reports are responsible for this new regulation.

This invasion appears to be above the Chadbourne Diversion and Cottonwood Reservoir. The FWP is not sure how the bass were introduced. Bass compete with native, wild species which the watershed is managed for. Yellowstone Cutthroat trout are native too the basin.

Under the new rules, anglers must kill and keep the smallmouth bass. They then must report and deliver the fish to a MTFWP office within 24 hours. The carcass must be delivered within 10 days providing their name, ALS number, and phone contacts.

In 2012, the Chadbourne Dam was upgraded to prevent Rainbow Trout from swimming upstream and hybridizing with native trout.

Some fishermen use Bucket Biology to move fish to a new watershed. This is illegal and NEVER a good idea.

Fish can be examined for their isotope ratios which can determine their origins. Smallmouth Bass are not native to Montana. Bass are major predators of trout and can devastate wild populations. Once a watershed is contaminated with an alien population, they are nearly impossible to eradicate. Just look at the Lake trout in Yellowstone Lake and Snakeheads in eastern states.

Small mouth Bass have also been found in other ponds, and rivers in Montana because of illegal transportation. Yellowstone and the Missouri rivers also have growing smallmouth populations. Just because there is water does not mean every type of fish needs to live there. Keep the Science and Biology in the hands of trained experts.

Invasive Smallmouth Bass are a Big Deal!

Montana Grant