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Idaho Steelhead Monitoring and Evaluation Study
2007-2009
Funded by Bonneville Power Administration
Tim Copeland, Kim Apperson
Fishery Biologists, McCall, Idaho
Idaho Fish and Game Dept.
IDFG Fish Technician Trap Operator
2007 - Mike Ackerman
2009 - Kiira Siitari
2007 Big Creek Screw Trap Summary
2008 Big Creek Screw Trap Summary
Idaho Fish and Game Fish Screw Trap on Big Creek
There are widespread ecological, economical, and sociological concerns surrounding the declining productivity of anadromous fish populations in Idaho, and as a result, a lot of recent attention has been focused on salmon and steelhead populations in the state. However, very little is known about the population dynamics and life history characteristics of these fish in our wilderness areas. In response to this situation, the Idaho Department of Fish and Game (IDFG), in cooperation with the University of Idaho’s Taylor Ranch Field Station (TRFS), initiated the monitoring and research of steelhead trout and Chinook salmon populations in the Big Creek drainage in the spring of 2007 through the deployment of a rotary screw trap. Big Creek will serve as an indicator watershed for the greater lower Middle Fork Salmon River drainage and the wilderness area.
  
Rotary screw traps are designed to live capture juvenile anadromous fishes that are migrating downstream en route to the ocean. This provides researchers with the opportunity to collect biological data and samples, as well as inject a subsample of fish with passive integrated transponder (PIT) tags. PIT tags provide individual Chinook and steelhead with a unique “social security number” and allow us to track fish as they migrate through the fish passage systems at the dams on their way to and back from the Pacific Ocean.
  
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IDFG’s goal for steelhead and Chinook in Big Creek is to reconstruct the egg-to-juvenile-to-adult life-cycle, and more specifically:
To estimate the number of juvenile Chinook and steelhead that are migrating out of the Big Creek watershed,
To estimate the yearly migratory survival rates through the Snake and Columbia Rivers of juvenile Chinook and steelhead from Big Creek,
To estimate the age structure of juvenile migrants, and
To describe the genetic structure of the watershed’s steelhead populations
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The Big Creek screw trap will be used in conjunction with PIT tag antenna arrays operated by National Oceanic and Atmospheric Administration (NOAA Fisheries) to investigate the population dynamics and life history characteristics of steelhead and Chinook salmon in Big Creek. The rotary screw trap located at TRFS was deployed on May 21st, 2007. During 2007 a total of 19,512 fish were captured in the screw trap. Of those, 2,425 steelhead and 5,503 Chinook salmon were PIT tagged and released back into Big Creek.
2008 - 2009 Season Update
The anadromous fish smolt trap "screw trap" was deployed in Big Creek in early March 2009 and will operate until November. The installation and operation of this instrument is a collaboration between Idaho Department of Fish and Game and Taylor Wilderness Research Station to provide data for research and monitoring of anadromous fish migration timing and numbers in a wilderness environment over 700 miles from the ocean, and to create educational opportunities for students to participate in hands-on field experiences. This year Kiira Siitari is the IDFG fisheries technician responsible for day-to-day trap operations, fish capture and PIT tagging, and data management. Undergraduate researcher Kristen Pilcher will incorporate data from the screw trap into her fisheries research project. In 2008 8,775 fish were captured in the screw trap, including 3,957 juvenile Chinook salmon and 1,774 juvenile steelhead trout. For additional information from 2007 and 2008 see the 2008 Big Creek Fish Screw Trap Summary above.
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