Monitoring of Outmigrant Juvenile Salmonids in the Trinity River Basin
Arcata Fish & Wildlife Office Fisheries Program
| Background: |
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In 1989, the Arcata Fish & Wildlife Office (AFWO) began
monitoring the abundance, timing, hatchery/natural
composition, and condition of juvenile salmon and
steelhead outmigrating from the Trinity River.
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The Trinity River Flow Evaluation Study used these data
to develop flow schedules conducive to smolt
temperature criteria, which were adopted in the 2000
Record of Decision for the Trinity River EIS/ROD.
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In 2001, monitoring was expanded through a joint
partnership with the Hoopa Valley and Yurok Tribes.
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To facilitate consistency and expedite analyses, AFWO
staff developed an integrated database and analytical
programs for processing outmigrant trapping data. This
system has been shared with our Tribal partners and is
being used by the Trinity River Restoration Program as
a prototype for other database and analytical systems.
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Current Program:
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Juvenile outmigrant monitoring provides the Restoration Program with information on the abundance and outmigration timing of anadromous salmonids, hatchery/natural stock production, and basic biological information needed to assess success of flow and habitat restoration actions.
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| Program Challenges: |
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Developing precise population estimates of salmonid
outmigrants has been a challenge due to the small
proportion of the river that can be effectively sampled.
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Sampling during high spring flows (>10,000 cfs) is difficult
because of physical limitations of the traps, large debris
loads, and physical safety to field crews.
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Smolt outmigrant trapping is expensive, as it requires
considerable staffing by field personnel.
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| Current Status: |
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A five-year status report for the lower trapping operation
has been completed and is undergoing an external review
prior to its release, scheduled for February 2007.
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An independent review of the TRRP trapping program is being initiated in 2007. This review will evaluate the
effectiveness of the trapping program at meeting TRRP objectives, and provide critical input for sample design
considerations.
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For more information contact Bill Pinnix, Fish Biologist, Arcata Fish and Wildlife Office, 707.822.7201 |
Last updated:
April 12, 2011