The Secesh River salmon abundance monitoring project is located in the South Fork Salmon River, in the Salmon River subbasin in Idaho. This project began in 1997 with underwater video salmon escapement monitoring in Lake Creek, a headwater tributary of the Secesh River. In 2004 the project transitioned to a natural origin salmon escapement monitoring project in the Secesh River which used dual frequency identification sonar (DIDSON). DIDSON was used to collect high precision estimates of adult escapement and spawner abundance information at the population level. The goal of this effort is to continue salmon abundance and productivity monitoring in a reference stream to maintain a long term data set. The Secesh River, which is an unsupplemented stream, acts as a reference stream for three ongoing supplementation program evaluations. Additional project information that is also collected includes salmon migration timing, fish per redd data, and evaluation of the relationship between escapement and redd count information. Information from this project is essential for effective population management, assessing effectiveness of conservation actions, viability, and listed species recovery metrics monitoring.
DIDSON is an innovative method for salmon escapement monitoring (view) that allows collection of near video quality images for identification of objects under water. The side scanning sonar allows passive determination of migrating salmon escapement on an annual basis, without trapping or handling of fish.