Since time immemorial, aboriginal people of the Confederated Tribes of the Warm Springs Reservation of Oregon (CTWSRO) have harvested fall Chinook salmon (Oncorhynchus tshawytscha) for subsistence, ceremonial, and medicinal purposes.  Not only is this species culturally significant, but it also has a high economic and recreational value to non-Indians.  The CTWSRO has co-management authority of fisheries resources in the Deschutes River with Oregon Department of Fish and Wildlife (ODFW).  Deschutes River fall Chinook are an indicator stock managed under the Pacific Salmon Treaty and is used to determine ocean harvest.  The CTWSRO has obligations to provide reliable escapement estimates to the United States Chinook Technical Committee, the body that implements the Pacific Salmon Treaty.  The ODFW has obligations to provide escapement estimates to the Columbia River Compact, which sets in-river harvest.

Much of the data collection for fall Chinook in the Deschutes Basin has centered on providing escapement estimates of returning adults.  Aerial surveys for fall Chinook redds, in conjunction with tagging returning adults at Sherars Falls (river kilometer, Rkm, 70) and Pelton trap (Rkm 161), and carcass surveys are used to estimate abundance.  Aerial redd surveys have been conducted in index reaches and/or from the mouth to Pelton Re-regulating Dam (Rkm, 161) since 1977 (Howell et al. 1985).  Prior to 1977, redd enumeration was conducted sporadically and sample areas were not consistent (Jonasson and Lindsay 1988).  Efforts to validate redd counts in the Deschutes River took place in 2007 (Baker et al. 2009) and 2009 (CTWSRO Natural Resources Branch Fisheries Research Dept. 2010).  Juvenile fall Chinook were tagged with coded wire tags (CWT) from April through June 1978 to 1980 (Jonasson and Lindsay 1988) and again from late-April or May through June 2002 to 2009 (Baker and Graham 2010).  Adult Chinook with CWTs recovered in various fisheries were reported through Pacific States Marine Fisheries Commission Regional Mark Processing Center.  In 2011, we conducted a PIT tag feasibility study to determine how many out-migrant juvenile fall chinook could be PIT tagged upstream of Sherars Falls.  Our efforts were successful in tagging 20,000 fish therefore efforts will be continued.

The limited data documenting juvenile fall Chinook ecology in the Deschutes River was collected as part of CWT studies.  Anticipated changes in the thermal regime, new information about genetic population structure of fall Chinook, and an upcoming opportunity to collect novel data on migration timing, smolt-to-adult ratios and possibly abundance estimates in the lower Deschutes River warrant further studies targeting the juvenile life history stage.  

In 2022, contract objectives include: 1) installation of a new PIT array at the mouth of the Deschutes River, which replaces a PIT array site that malfunctioned, and had limited detection efficiency, 2) maintenance and operation of a second PIT array near Shaer Falls to detect juvenile and adult fall Chinook salmon and other PIT tagged salmonids, 3) Assisting of ODFW in operation of their adult trap and mark recapture tagging efforts, 4) Conduct carcass surveys to recover floy and PIT tags, for mark recapture escapement estimates.  

Baker, C., J. C. Graham, and M. Fox. 2009. Aerial redd count validation for improving fall Chinook salmon abundance estimates in the Deschutes River, Oregon. Confederated Tribes of the Warm Springs Reservation of Oregon, Warm Springs, OR.
Baker, C. F., and J. Graham. 2010. Coded wire tagging of fall Chinook salmon in the Deschutes River, Oregon.  2002 - 2009 summary report. Confederated Tribes of the Warm Springs Reservation of Oregon, Warm Springs, OR.
CTWSRO Natural Resources Branch Fisheries Research Dept. 2010. Deschutes River Fall Chinook Research and Monitoring. Confederated Tribes of the Warm Springs Reservation of Oregon, Warm Springs, Oregon.
Howell, P. J., and coauthors. 1985. Stock assessment of Columbia River anadromous salmonids volume I: Chinook, coho, chum, sockeye stock summaries. Report to Bonneville Power Administration, Contract DE-A179-84BP12737, Project 83-85.  Bonneville Power Administration, Portland, OR.
Jonasson, B. C., and R. B. Lindsay. 1988. Fall chinook salmon in the Deschutes River, Oregon. Oregon Department of Fish and Wildlife, Portland, Oregon.