Hydroacoustic Evaluation of Juvenile Salmon Passage at the Dalles Dam: 1999
ENGINEER RESEARCH AND DEVELOPMENT CENTER VICKSBURG MS ENVIRONMENTAL LAB
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This study compares hydroacoustics-based estimates of fish passage and passage metrics for two spill treatments 30- and 64-percent spills and concomitant powerhouse operations at The Dalles Dam during the 1000 spring and summer juvenile salmon passage seasons. Data were analyzed for significant differences Wilcoxen Signed-Rank Tests, alpha 0.05 in daytime nighttime, and total daily fish passage and passage metrics over six 3-day treatment blocks in spring and summer. Horizontal distributions of fish passage at spillway and powerhouse and vertical distributions of fish at sluiceway and powerhouse are presented by treatment and time of day for each season. Project fish-passage efficiency FPE and spill efficiency were significantly higher with the higher spill and lower powerhouse generation treatment at night but not during days in both seasons. Sluiceway efficiency was higher with the lower spill and higher generation treatment at night in spring and both night and day in summer. Spill passage was not significantly different during day or night in spring but was higher with the higher spill treatment during summer nights but not days. Sluiceway passage was higher during spring days and nights during the 30-percent spill than during the 64-percent spill but not different during days or nights in summer. Turbine passage was higher with the lower spill treatment at night in both seasons. Results should be considered in light of the confounding effects of higher spill vs. lower generation and the converse, which was inherent in the experimental design. Statistical methods, a detailed evaluation of the acoustic screen model, and an evaluation of two methods for estimating passage at unsampled spill bays are presented in the appendixes.
- Acoustic Detection and Detectors