Evaluation of the Prototype Surface Bypass for Salmonid Smolts in Spring 1996 and 1997 at Lower Granite Dam on the Snake River, Washington

Abstract

In spring 1996 and 1997, we studied the prototype surface bypass and collector (SBC) at Lower Granite Dam on the Snake River in Washington. Our objectives were to determine the most efficient SBC configuration and to describe smolt movements and swimming behavior in the forebay. To do this, we used hydroacoustic and radiotelemetry techniques. The SBC was retrofitted onto the upstream face of the north half of the powerhouse to test the surface bypass method of diverting smolts from turbines. The SBC had three entrances, with mean velocities ranging from 0.37 to 1.92 m/s, and it discharged 113 m 3 /s through its outlet at Spill Bay 1, which was adjacent to the powerhouse. Different SBC configurations were created by altering the size and shape of entrances. During spring 1996 and 1997, river discharge was well above normal (123 and 154% of average, respectively). Powerhouse operations caused a strong downward component of flow upstream of the SBC. Many smolts (primarily steelhead and secondarily chinook salmon) were observed actively swimming upward in the water column. There were four times as many smolts diverted from turbines per unit volume of water with SBC flow than with spill flow, which indicated that the SBC may be an especially important bypass consideration in moderate-or low-flow years. The highest SBC efficiency (the proportion of total fish passing through the north half of the powerhouse by all routes that passed through the SBC) for any configuration tested was about 40%. Although no single SBC configuration stood out as the most efficient, the horizontal surface and maximum area configurations, or some combination of the two, are worth further investigation because they were moderately efficient.

A Markov chain analysis of fish movements to determine entrainment zones

“…In biotelemetry studies, fish are captured, tagged with a radio or an acoustic transmitter, and released (Tytler et al, 1978;Moore and Potter, 1994;Johnson et al, 2000). The tagged fish are tracked with mobile and fixed arrays of receivers.…”

Sluiceway Operations for Adult Steelhead Downstream Passage at The Dalles Dam, Columbia River, USA

“…Data analysis.-The adult fish we detected were assumed to be prespawn (fallbacks) and postspawn (kelts) steelhead because of their acoustically detected size, as revealed by the fixed-aspect hydroacoustic systems. The acoustic images from the DIDSON camera verified that the targets were adult salmonids; the images showed the typical morphology of large adult salmonids and that these fish passed into the sluiceway tail-first, which is common salmonid behavior (Johnson et al 2000;Scruton et al 2003). The DIDSON samples did not show other types of large fishes entering the sluiceway during the sampling periods when it was used.…”

“…Many of these dams were designed and constructed with fishways (fish ladders) to provide passage routes for upstream migrants (Coutant and Whitney 2000;Williams et al 2001;Arnekleiv et al 2007); in general, fish migrating downstream must pass through dams by way of turbines, spillways, and sluiceways (Raymond 1988;Coutant and Whitney 2000;Johnson et al 2000;Williams et al 2001;Johnson and Dauble 2006;Arnekleiv et al 2007). Turbine passage, however, can be detrimental to fishes because they may be killed or injured as they pass through the turbines (Coutant and Whitney 2000;Williams et al 2001;Johnson and Dauble 2006).…”

Effects of antenna length and material on output power and detection of miniature radio transmitters

“…In some studies, using radio tags with antennas coiled within the embedding material could obviate the need for ''shorter'' trailing antennas. Coiled antennas generally result in lower output power than trailing antennas (Cooke & Bunt, 2001) and may be inappropriate in cases where output power is important, such as for determining accurate pulse intervals or where reception distances need to be maximized due to large study areas or small detection fields (Beeman et al, 1998;Johnson et al, 2000).…”

“…The use of smaller internal components has decreased the size and weight such that tags weighing less than 1.0 g are readily available, enabling studies of smaller fishes than ever before. Radio telemetry has proven useful in many studies, including evaluations of dam passage behavior, habitat use, and responses to environmental conditions (Cheek et al, 1985;Martinelli & Shively, 1997;Johnson et al, 2000;Moser et al, 2002). Evaluations of the effects of radio transmitter (tag) presence on fish performance and behavior have been conducted on a variety of species, providing recommended tag-weight to bodyweight ratios, attachment procedures, and detection methods (Winter, 1996;Martinelli & Shively, 1997;Beeman et al, 2004).…”