Age-structured state-space spawner-recruit models were fit to 1986-2015 data on abundance, harvest, and age composition for early and late runs of Kenai River Chinook salmon (Oncorhynchus tshawytscha), 75 cm mid eye to tail fork (METF) and longer. Historical annual run abundance, stock recruitment parameters, and fishery management reference points were estimated from these models. Sustainable Escapement Goals of 2,800-5,600 (early run) and 13,500-27,000 (late run) Chinook salmon 75 cm METF and longer are recommended, and their attributes and limitations discussed. Fish 75 cm METF (approximately 33.3 in total length) and longer can be assessed directly by imaging sonar in the Kenai River at river mile 13.7.

Historical abundance of Andreafsky River, Anvik River, and aggregated other upriver stocks of summer chum salmon Oncorhynchus keta was reconstructed from mixed stock harvest data and incomplete sonar, weir, counting tower, and aerial survey data of varying precision from 1972 to 2007. The resulting estimates of escapement and harvest of East Fork Andreafsky River chum salmon were fitted to an age-structured Ricker spawner-recruit model. Bayesian statistical methods were employed, which allowed for realistic assessment of uncertainty in the presence of measurement error, serial correlation, and missing data.

Report discusses the results of estimating chinook salmon, Oncorhynchus tshawytscha, abundance in the Kenai River May-June and July-August 2006, using split-beam sonar technology.

Historical escapement and run size of fall chum salmon Oncorhynchus keta was reconstructed from incomplete sonar, weir, counting tower, mark-recapture, aerial survey, and foot survey data of varying precision from 1974 to 2007. The resulting estimates of drainage-wide escapement were fitted to an age-structured Ricker spawner-recruit model. Bayesian statistical methods were employed, which allowed for realistic assessment of uncertainty in the presence of measurement error, serial correlation, and missing data.

In 2013, Kenai River Chinook salmon (Oncorhynchus tshawytscha) passage was estimated using Adaptive Resolution Imaging Sonar (ARIS) at a newly established site at river mile 13.7. Medium and large Chinook salmon (greater than or equal to 75 cm as measured by ARIS) were directly assessed by the sonar, yielding net upstream passage estimates of 1,724 (SE 93) during the early run (17 May-30 June) and 12,656 (SE 282) during the late run (1 July-17 August). Smaller Chinook salmon (less than 75 cm ARIS length) overlap in size with other species; thus a combination of sonar, netting, telemetry, and weir data from this and other projects are required for assessing the abundance of all Kenai River Chinook salmon regardless of size. During the 2013 early run, telemetry and weir data were used to obtain a net upstream passage estimate of 2,806 (SE 341) small Chinook salmon; this estimate was combined with the ARIS estimate of medium and large Chinook salmon for a total of 4,530 (SE 353) Chinook salmon regardless of size. During the late run, a mixture model was fitted to sonar and netting data to obtain a net upstream passage estimate of 19,373 (SE 583) Chinook salmon regardless of size.

Report discusses the results of estimating chinook salmon (Oncorhynchus tshawytscha) abundance in the Kenai River May-June and July-August 2010, using split-beam sonar and experimental dual-frequency identification sonar (DIDSON) technology.