Monitoring fish movement patterns in a reservoir using horizontally scanning split-beam techniques

Abstract

Horizontally scanning split-beam hydroacoustics was used to monitor downstream migrating juvenile salmon and steelhead trout smolts (Oncorhynchus spp.). The study was conducted in the reservoir of Rocky Reach Dam on the Columbia River (Washington, USA). The objective was to determine the movement patterns of smolts as they migrated through the reservoir. Scanning split-beam hydroacoustic techniques and three-dimensional target tracking were combined with remote multiplexing with the aim of investigating smolt movement patterns in the reservoir. The trajectory profiles, target strength distributions, and horizontal distributions of the smolts were estimated for each of six different aiming configurations utilizing six different elliptical split-beam transducers. The results of this study were used to determine the optimal location for installing a surface collector and bypass system. This system will be used to collect and bypass smolts past the dam, a safer alternative to passing through the turbines. The results showed that fish migrated downstream primarily along the east side of the reservoir, concentrated in the upper water column. Few fish were seen migrating down the western shoreline. At the southern end of the reservoir, there were areas where the fish congregated into relatively large schools before proceeding on their downstream migration. Following this study, a smolt bypass system has been installed and is currently being evaluated.1996 International Council for the Exploration of the Sea

The River Management Modelling For Ecology

“…A sample of river modelling is seen in Figure 4 about Rocky Reach Dam in U.S. state of Chelan / Douglas counties, Washington and Army Corps of Engineers illustration of juvenile fish bypass. Also it explained and studied the reservoir of Rocky Reach Dam [7,8].…”

Acoustical estimates of fish and zooplankton distribution in the Piaseczno reservoir, Southern Poland

“…Unquestionable advantage of hydroacoustics over traditional fishery methods is its high speed which greatly improves the ability to sample fish on a lakewide scale and allows to study dynamic changes in fish distributions, such as swarming behavior, diurnal horizontal and vertical migrations, etc. (Freon et al 1996;Marchal and Lebourges 1996;Steig and Johnston 1996;Comeau and Boisclair 1998;Guillard 1998). Its disadvantages are due to difficulties close to lake surface and bottom and inability to distinguish between species and sometimes even between the fish and other objects such as invertebrates, air bubbles or aquatic macrophytes (Kubecka et al 1993;Trevorrow and Tanaka 1997;Nealson and Gregory 2000;Trevorrow 2000;Rudstam et al 2002).…”

A floating device for stationary hydroacoustic sampling in shallow waters

“…Furthermore, simultaneous measurement of the current velocities where the fish swim is of major importance to understand fish distribution and swimming behavior (e.g. Steig and Johnston, 1996).…”