Interrogation Site Metadata

This site consists of a single 20 ft wide by 8 ft deep pass-through antenna placed perpendicular to river current at Clearwater River rkm 10 at the site of the discontinued Clearwater Trap (CLWTRP). The purpose of the antenna is to detect juvenile salmonids as they transition from the free-flowing Clearwater River to Lower Granite Dam Reservoir while emigrating downstream. The antenna is the same NOAA Fisheries design used at PD8. The antenna is mounted on a 20 ft beam on a 6 ft x 10’ pontoon raft with an IS1001 Biomark reader and two 12v batteries. Data is manually downloaded when the batteries are changed every two weeks. The pontoon raft and antenna are held in position by a cable connecting the raft to the CLWTRP traps high line crossing the Clearwater River, and by 30 lb anchors at each end of the 20 ft wide antenna. The antenna is positioned 16 m - 26 m south of the north bank using CLWTRP’s hydraulic winch system. The depth of the antenna may be less than 8’ feet due river current pushing the sides and bottom of antenna downstream.

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