The Distribution and Flux of Fish in the Forebay of The Dalles Dam in 2003

Faber, Derrek M. ; Hanks, Michael E. ; Zimmerman, Shon A. ; Skalski, John R. ; Dillingham, Peter W.

Pacific Northwest National Laboratory (U.S.)

关键词: U.S. Army Corps Of Engineers;    Us Corps Of Engineers;    The Dalles Dam;    Juveniles;    Salmon;   

DOI  :  10.2172/15020675
RP-ID  :  PNNL-14628
RP-ID  :  AC05-76RL01830
RP-ID  :  15020675

美国|英语

来源: UNT Digital Library

【 摘 要 】

In spring and summer 2003, the Pacific Northwest National Laboratory led a team that conducted mobile and fixed hydroacoustic surveys in the forebay of The Dalles Dam for the U.S. Army Corps of Engineers - Portland District, for the Anadromous Fish Evaluation Program. The surveys provided information on the distribution and movement of smolt-sized fish relative to ambient factors such as flow, bathymetry, or diel cycle in the forebay at The Dalles Dam. This information is intended to provide baseline data for the development of a surface bypass alternative for juvenile salmon at The Dalles Dam. We sampled the forebay of The Dallas Dam one day and night each week for six weeks in the spring and another six weeks in the summer. In general, during the day in the spring, the greatest densities of smolt-sized fish were observed in the thalweg of the main channel from the Washington bank, to the east side of the powerhouse, along the powerhouse, and concentrated in the areas next to the sluiceway. Fish density was lower on the Washington side of the river and west of mid-powerhouse (north spillway side). The spring night distribution was similar, with a few notable differences. The density of fish was high on the east side of the powerhouse and along the face of the powerhouse, and more fish were detected on the north spillway side. The distribution of sub-yearling sized fish in summer followed the same general patterns as spring, except that summer fish had a greater presence on the east side of the powerhouse and on the north spillway side. The vertical distribution of fish was also determined. In spring 80% of fish were above 5.6 m of depth during the day and above 4.7 m in the night. The summer fish were similarly distributed in the day and night with 80% of the fish in the upper 4.5 m and 4.7 m of the water column respectively. In general the smolt-sized fish were distributed deeper in the water column in the center of the channel than near the edges. The net movement of smolt-sized fish in the forebay from fixed-point samples appeared to be in a circular pattern, with fish moving with the flow and channel upstream of the powerhouse, and upstream at points near the powerhouse. The rate of fish movement (flux) was greatest at the east end of the powerhouse and on the upstream-north side of the channel.