On October 7th, HFF worked with partners from Fall River Rural Electric and the U.S. Forest Service to remove the outmigrant trap that was part of our Buffalo River project. The decision to remove the trap was made jointly by HFF, Fall River Rural Electric, U.S. Forest Service, and Idaho Department of Fish and Game, after reviewing data collected at the downstream trap since 2009. Through the trap’s operation, we have learned that many thousands of young rainbow trout migrate downstream out of the Buffalo River each spring. The vast majority of these young fish were spawned in the Buffalo River. On-going genetics work will tell us how many of these Buffalo River fish contribute to the population of rainbow trout available to anglers in the Henry’s Fork. In addition, continued monitoring of the fish ladder and the PIT-tag detection antenna will allow us to track fish use of the Buffalo River.
The outmigrant trap itself is very inefficient at capturing. The trap had started to degrade and fall apart, making it even less useful as a research and monitoring tool. In the spring of 2015, we lost several weeks of monitoring due to infrastructure failures. We decided that the continued cost of maintaining and operating the trap outweighed the additional data we could collect from it, given that we are now using more modern genetics and PIT-tag methods to study the dependence of the Henry’s Fork rainbow trout population on the Buffalo River.
HFF's research team is working with partners to create a report that will summarize findings from all of the data collected in the past 10 years. This report, which should be complete next year, will help us make long-term decisions regarding the future of the fish ladder and trap, as well as help us identify potential restoration needs on the Buffalo River to increase crucial spawning habitat.