The Feasibility of Documenting and Estimating Adult Fish Passage at Large Hydroelectric Facilities in the Snake River Using Video Technology: Final Report 1993
A field study was conducted at Lower Granite Dam on the Snake River in 1992 and 1993 to evaluate the feasibility of using video technology to document and estimate fish ladder passage of chinook salmon Oncorhynchus tshawytscha, sockeye salmon 0. nerka, and steelhead 0. mykiss. Through the two years of study, a video system was developed and used that produced video images during salmon passage periods. A technician identified and counted fish images from the video record. Fish ladder passage estimates of target species made from the video record were similar to estimates made by on-site counters during daytime periods, indicating that the two methods were relatively precise. We also found that at Lower Granite Dam, a significant percentage (6.4% and 8.3%) of target salmonids migrated during nighttime periods when on-site counts were not typically made during the two years of study. Analysis of the video record permitted verification of individual sockeye salmon identified and counted by on-site count personnel, and provided data useful to managers of this ESA-listed stock.
Hatch, D.R., D.R. Pederson, J.K. Fryer, M. Schwartzberg, and A. Wand. 1994. The feasibility of documenting and estimating adult fish passage at large hydroelectric facilities in the Snake River using video technology: final report 1993. Bonneville Power Administration, Portland, OR. Project Number 1992-055. 131p.