bulltroutfinalreport2017.pdf

Bull trout were listed as threatened under the Endangered Species Act in 1998 due to declining populations. The U. S. Fish and Wildlife Service (Service) recommends monitoring bull trout in subbasins where little is known about the populations, including the Grande Ronde and Imnaha subbasins. Spawning survey data is important for determining relative abundance and distribution trends in bull trout populations. This report summarizes the 2017 bull trout spawning data collected in the Wallowa Mountains of northeast Oregon and compares this with past years’ data. Bull trout spawning surveys have been conducted on similar index areas for selected Grande Ronde and Imnaha River streams from 1999 to 2017. These surveyed streams are located within the Wallowa River/Minam River and Imnaha River bull trout core areas. Surveys in 2017 were conducted by the Nez Perce Tribe (NPT), the Oregon Department of Fish and Wildlife (ODFW), the Service, U.S. Forest Service (USFS), Freshwater Trust, and fisheries consultants. Objectives of the survey included: (1) locate bull trout spawning areas; (2) determine redd characteristics; (3) determine bull trout timing of spawning; (4) collect spawning density data; (5) determine and compare the spatial distribution of redds along the Lostine River in 2006 through 2017; and (6) over time use all of the data to assess local bull trout population trends and the long-term recovery of bull trout. Timing of spawning, total redds, redd sizes, and redd locations are documented in the report. The local bull trout populations were relatively stable for the survey period (1999-2017). There was a decrease in redd numbers in Big Sheep Creek in 2017 compared to 2016. There was an increase in redd numbers on the Imnaha River, the Lostine River, and Bear/Goat Creek in 2017 compared to 2016. The increases were not significant for the Imnaha, the redd numbers were still low compared to 2014 and previous years. However, the increases were significant for the Lostine and Bear/Goat Creek. The Imnaha population is one of the strongholds within the Imnaha Subbasin. Big Sheep Creek and Little Sheep Creek populations within the Imnaha River core area are of concern for long-term viability due to issues with stream flows, fish passage fish passage
Fish passage is the ability of fish or other aquatic species to move freely throughout their life to find food, reproduce, and complete their natural migration cycles. Millions of barriers to fish passage across the country are fragmenting habitat and leading to species declines. The U.S. Fish and Wildlife Service's National Fish Passage Program is working to reconnect watersheds to benefit both wildlife and people.

Learn more about fish passage , and connectivity. The Lostine River and Bear Creek contain brook trout and hybridization is likely occurring. In 2010 and 2012, bull trout and brook trout were documented paired up for spawning on the Lostine River.