The Chinook Salmon Adult Abundance Monitoring project collects data for long term monitoring of trends in natural origin (wild) adult salmon escapement and productivity.  This information is used for effective population management and for use in threatened species recovery monitoring.  Salmon escapement and productivity data collection occurs in the Secesh River.  The Secesh River is the only stream in the entire Snake River basin where natural origin salmon escapement and productivity data are collected absent a hatchery supplementation program.  Natural origin escapement and productivity information from the Secesh River provides for supplementation program reference stream comparison, and for Interior Columbia Basin Technical Recovery Team population viability analysis.  Accurate and precise measurement of adult salmon escapement will be accomplished using dual frequency identification sonar (DIDSON) acoustic imaging techniques.  

This project utilizes DIDSON technology to provide adult salmon escapement information on an annual basis.  As adult salmon migrate upstream through the monitoring site, escapement information is collected via DIDSON sonar on the Secesh River.  The passive DIDSON monitoring approach allows unimpeded upstream and downstream fish movement, and precludes incidental trapping and handling mortality of a listed species.  Information collected from this project will allow comparison to redd count survey data to assess if redd count information provides reliable indices of adult salmon escapement.  Accurate abundance data is necessary to calculate derived performance measures such as smolt-to-adult returns, spawner-to spawner ratios, recruits per spawner, population growth rates (lambda) and population trends.  Accurate and precise escapement information has been recognized as necessary component for status monitoring and assessment of progress toward recovery goal metrics for threatened Snake River basin chinook salmon.

Coordination will occur with Idaho Supplementation Studies (ISS), the Johnson Creek Artificial Propagation Enhancement program (JCAPE), and the northeast Oregon Hatchery project (NEOH) as the Secesh River represents a control/reference stream for those supplementation programs.  ISS studies will further complement this investigation as they routinely estimate juvenile emigrant abundance which can be used to develop recruit per spawner relationships and smolt-to-adult return rates via life cycle monitoring in the Secesh River.  The ISS project also collects scales and fin rays from salmon carcasses which allows fish ageing and determination of age at return from various brood years.  This provides data to determine productivity (progeny-per-parent ratios).  The Integrated Status and Effectiveness Monitoring project in the South Fork Salmon River explicitly states a need for adult salmon escapement information in the Secesh River at the population level.  Salmon abundance and productivity monitoring on wild populations is also a clearly identified need in the Salmon Subbasin Management Plan (Ecovista 2004).  Federal and state fisheries agencies from Idaho, Oregon, Washington and Alaska have consulted with this project concerning the application of DIDSON technology to monitor salmon escapement.  Discussion of standardized data collection, methods, linkages to other research projects has and will continue to occur.  This project may become a component of a larger comprehensive monitoring and evaluation plan for quantifying salmon escapement, productivity, life stage specific survival, and population growth for index populations.

The Chinook Salmon Adult Abundance Monitoring project is located in the Secesh River drainage of west central Idaho.  The Secesh River is a tributary to the South Fork Salmon River.  The DIDSON acoustic camera site is located on the Secesh River (rkm 30) and is located downstream of the vast majority of available salmon spawning habitat.