Fisheries, Subsistence, and Habitat
Publications Searchable Database
Search Again| Division: | Sport Fish |
| Title: | Estimates of Chinook salmon passage in the Kenai River using split-beam and dual-frequency identification sonars, 2010 |
| Author: | Miller, J. D., D. L. Burwen, and S. J. Fleischman |
| Year: | 2013 |
| Report ID: | Alaska Department of Fish and Game, Fishery Data Series No. 13-58, Anchorage |
| Abstract: | Kenai River Chinook salmon (Oncorhynchus tshawytscha) passage was estimated in 2010 using split-beam sonar and experimental dual-frequency identification sonar (DIDSON). The split-beam sonar operated continuously from 16 May to 4 August, when operations were curtailed due to milling salmon that prevented accurate counting. The DIDSON was successfully deployed on both banks of the river and operated successfully on 48 days between 11 June and 10 August. Based on split-beam sonar target strength and range thresholds, total upstream passage of Chinook salmon was estimated to be 13,248 (SE 235) fish during the early run (16 May–30 June) and 48,343 (SE 726) fish during the late run (1 July–4 August only). Based on DIDSON length measurements and inriver netting catch rates, estimates of Chinook salmon passage were 5,874 (SE 645) fish for the early run (16 May–30 June) and 18,401 (SE 698) fish for the late run (1 July–10 August). Detailed comparisons of split-beam and DIDSON data indicated that the assumptions underpinning split-beam target-strength-based estimates are not valid. It is recommended that target-strength-based split-beam sonar estimates be discontinued in favor of DIDSON-based estimates in 2011. |
| Keywords: | split-beam sonar, DIDSON, Chinook salmon, Oncorhynchus tshawytscha, acoustic assessment, Kenai River, riverine sonar |