Area Management Biologist
February 18, 2015
In an effort to better assess early and late run king salmon abundance on the Kenai River in 2015, the Alaska Department of Fish and Game will begin using sonar estimates from a site at River Mile 14 instead of sonar estimates from a site at River Mile 9.
“The new location allows sonar technology to span nearly the entire width of the river, which will result in more accurate assessments,” Robert Begich, the Area Management Biologist in Soldotna, said. “The sonar at River Mile 9 only counted fish moving up the middle of the river, and we know from other means such as gillnetting and a mark-recapture project that some fish were not observed by the sonar.”
During 2013 and 2014, the department operated sonars at both River Mile 14 and River Mile 9 as part of a research project to determine if the king salmon runs could be assessed by sonar at River Mile 14. Findings from the research project showed that the River Mile 14 sonar provided king salmon abundance assessments that were equivalent, on average, to the expanded estimates used for in-season management of the fishery from the sonar located at River Mile 9.
While the abundance of large king salmon can be assessed directly by the sonar at River Mile 14, test netting projects at River Mile 9 will continue in 2015. Assessing the abundance of all king salmon (regardless of size) requires sonar data be supplemented by additional information from the test netting project.
The department will begin operating the sonar at River Mile 14 on May 16 and will discontinue the sonar project at River Mile 9. Achievement of the existing escapement goals (5,300–9,000 early run; 15,000–30,000 late run) will continue to be the management objective for the king salmon fishery.
For more information about the Kenai River king salmon assessment program and to read a list of frequently asked questions, please visit the ADF&G webpage at: http://www.adfg.alaska.gov/index.cfm?adfg=sonar.kenai .