NPT 2019 Bull Trout Redd Counts - revised by RR 2020-10-21.pdf

This report summarizes Bull Trout redd counts from surveys conducted in the Grande Ronde and Imnaha subbasins in 2019 and compares those with prior years. Streams surveyed in 2019 included: South Fork Wenaha River, Milk Creek, Butte Creek, Lostine River, Bear Creek, Goat Creek, Big Sheep Creek, and Lick Creek. In most surveyed streams, redd counts were average to slightly below average compared to previous years. Observed redd densities in 2018 and 2019 on the South Fork Wenaha River reflect a healthy population. We suggest using the surveyed reaches of the South Fork Wenaha River as an index reach for future monitoring of that system. We plan to continue long-term population monitoring via redd counts in priority streams in the future, though some surveys will not be conducted on an annual basis but rather on an interval schedule (e.g., 5-10 year intervals). Starting in 2020, additional monitoring strategies (e.g., eDNA, electrofishing, and/or snorkeling) will be deployed to fill information gaps on distribution and relative abundance of bull trout and brook trout, especially in basins where hybridization is a primary threat.