Passage behavior and survival of radio-tagged yearling and subyearling chinook salmon and juvenile steelhead at Ice Harbor Dam, 2008

In 2008, we evaluated passage behavior, distribution, and survival of yearling Chinook salmon, steelhead, and subyearling Chinook salmon at Ice Harbor Dam. A central objective ofthese evaluations was to determine the effects of a removable spillway weir (RSW) used during two different spill operations. Study fish consisted of those collected and surgically tagged with both a radio transmitter and PIT tag for similar evaluations at Lower Monumental Dam. For the Ice Harbor evaluation, treatment groups consisted offish released either 42 km above Lower Monumental Dam or into the tailrace of Lower Monumental Dam. These fish were regrouped by day of detection on the Ice Harbor forebay entry line, 600 m upstream from the dam. A total of 1,699 yearling Chinook salmon, 1,951 juvenile steelhead, and 2,314 subyearling Chinook salmon from these releases were obtained as treatment fish in this manner. Contract no. W68SBV80438584