Day, night, and winter fish counts from 15 Corps fishladders are reported on these pages.
Day fish counts (4 a.m. - 8 p.m. PST each day from April 1 through Oct. 31 each year) are taken by fish counters looking directly into the fishladders. They count the fish passing by 50 minutes each hour.
To account for the fish that pass by during the breaks they take (160 minutes of break), we add the counts made during the day's counting periods (800 minutes of counting), multiply the total by 1.2, round to the nearest whole fish, and present that number as our estimate of the day count in each ladder.
The fish counters are currently taking separate counts of adult chinook, jack chinook, clipped steelhead, unclipped steelhead, adult coho, jack coho, sockeye, chum, pink, shad, and lamprey. We add the adult chinook and jack chinook day estimates together to get All chinook, clipped steelhead and unclipped steelhead day estimates together to get All steelhead, and adult coho and jack coho day estimates together to get "All" coho. When night (8 p.m. - 4 a.m. PST each day) or winter (Nov. 1 through March 31) fish counts are taken, the fish counters use video, recording and reading the entire 60 minutes of each hour, so no estimation is necessary.
The counting schedules we maintain, which fish species are counted, how the counts are reported, and the methods for expansion or estimations we use are determined by the Fish Passage and Operations Management committee, who are NOAA, CRITFC, ODFW, WDFW, IDFW, BPA, and COE biologists.