Nick, what are fish barriers, and why are they used?
Great question. It can get confusing when you hear about fish barriers and fish passage projects across Wyoming. Though all of our work in fish passage involves removing and improving barriers to allow upstream passages for fish there are a few cases where constructing a barrier is our best management option to effectively manage a fishery.
Unlike hydropower and irrigation dams, these fish barriers’ sole purpose is to block upstream movement of all fish. Reasons these are built include:
protecting native fish upstream. We protect them from hybridization and competition with species downstream, stopping non-native fish species from expanding their range, and restoring native species above the barrier.
A few streams where barriers have been constructed include upper Labarge Creek and Bare Creek in the Wyoming Range to restore native Colorado River cutthroat trout populations. A barrier on the Big Sandy River was just completed to protect flannelmouth sucker, bluehead sucker, and roundtail chub populations. Populations of all three of these species that are presently found upstream from the barrier have drastically declined across Wyoming and their native range in other states.
It is always best to have passage and interconnected streams, but sometimes barriers are a great tool.