|材料类型：||文献, 政府刊物, 州政府或者省政府刊物, 互联网资源|
|文件类型：||书, 计算机文档, 互联网资源|
Heath D Sandall; Carl T Pfisterer; Alaska. Division of Sport Fish.; Alaska. Division of Commercial Fisheries.
|注意：||"Alaska Department of Fish and Game, Divisions of Sport Fish and Commercial Fisheries"--Cover.
|描述：||ii, 50 p. : ill., map ; 28 cm.|
|详述：||This item was harvested from the Fish and Game web site: http://www.sf.adfg.state.ak.us/FedAidPDFs/fds06-32.pdf in July 2006 for the Alaska State Publications Program; remote access available via StaticURL.|
|丛书名：||Fishery data series, no. 06-32.|
|责任：||by Heath D. Sandall and Carl T. Pfisterer.|
The Aniak River sonar project has provided daily fish passage estimates for most years since 1980. During this time, the project has undergone important changes including changing from the original Bendix sonar to dual-beam and is in the process of migrating to a high frequency imaging sonar (DIDSON). This season, the project adopted a new sampling protocol in which the sonar operated for three 4-hour blocks each day (0000-0400, 0800-1200, and 1600-2000 hours). The Aniak River sonar project was operational from 28 June through 31 July in 2003. During this period, an estimated 393,396 fish (SE 7,871) passed through the ensonified area. The peak passage of 23,208 fish occurred on 14 July and the 50% passage date occurred on 17-July. The escapement estimate was primarily comprised of age-0.3 fish (80.6%), while age -0.4 (17.9%), -0.5 (1.1%) and -0.2 (0.4%) classes were also present. Side-by-side comparisons of counts obtained with the BioSonics and DIDSON equipment suggest undercounting with the BioSonics at high densities.