Fish Weir on Shitike Creek provides information to Biologists

The resistance-board weir is in Shitike Creek and is designed to operate year-round to capture (or view) adult spring Chinook and steelhead who are traveling upstream to reproduce.  Species can be counted while traveling up or downstream in a two-way trap box or on video.  The weir captures all fish from the beginning of the steelhead upstream movement (mid December) until daily maximum temperature reaches 17 °C.  Once daily maximum water temperatures reach 17 °C (by late May), the two-way trap box is opened for movement through the weir.  This is typically when adult spring Chinook begin to move through the weir.  Fish are then counted by video observation.  An underwater video camera is then set up so fish can be counted as they move up and down stream.  There are special underwater lights that allow us to count fish 24 hours every day.  Video monitoring continues until steelhead upstream movement resumes.

Fisheries research is currently conducting total annual counts of adult movement for spring Chinook and steelhead as well as other fish species caught and/or observed by video for 2017. Of those fish counted fisheries research collects other data which create a more complete picture and aids us in understanding how many steelhead and spring Chinook we can expect to see in the coming years and if any measures need to be taken to help the species’.

Data is currently being collected for 2017 at the resistance board weir.  Preliminary adult spring Chinook counts for 2017 look comparable to the last years sampled and the migration is not completed yet (Figure 1).

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Figure 1. Number of adult salmon upstream of Shitike weir. Note that no samples were taken in 2015 and 2016 and counts for 2017 are still in progress.
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Figure 2. Mr. Lyman Jim surveys weir after installation.
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Figure 3. Resistance board weir in action. The part of the weir that is laying down in the stream is designed to block passage but at the same time let debris or increased water flow over weir so it can operate year round and not blow out.
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Figure 4. A wild adult male spring Chinook passes the video weir headed up stream to reproduce on September 2nd, 2017 at 9:27 PM.
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Figure 5. A family of river otters stops by to say “cheese” while passing through the video weir on August 23rd, 2017 at 08:31 AM.