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How are weirs used?
Collecting information on the abundance and timing of migratory fish is an important component
of anadromous fisheries management.
Resistance board weirs
can be used...
- to obtain accurate direct counts of salmonid
escapement
or other migratory species
- for
passive monitoring
of fish passage with still/video cameras [example],
Vaki RiverWatcher
[example],
acoustic tags, or
PIT tags
[example].
- to actively trap and process fish for tag recovery or tissue sampling
- for broodstock selection and segregation [example]
- to segregate hatchery and natural origin fish ["Hatchery Reform"]
- to segregate spring and fall run Chinook salmon ["Lake Oroville Settlement Agreement"; PDF]
Data collected through our weirs can be used to analyze population parameters including: species
composition; age structure; run timing and migratory patterns; fish condition; sex ratio; and
abundance. Furthermore, weir data provides comparatively more accurate information than
traditional methods such as spawning surveys (i.e., redd and spawner counts and carcass
mark-recapture
population estimates).
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