Escapement Updates
2011 FRASER SOCKEYE
ESCAPEMENT UPDATES
This site provides inseason updates
from operational sockeye salmon escapement estimation field
studies in the Fraser River, including fence counts, mark-recapture
studies, DIDSON projects, visual surveys, and physical (water
temperature, level) and fish condition. These updates are intended
to provide general information regarding project activities,
run timing and relative abundance, and should not be interpreted
as escapement estimates. Inseason updates will be posted in
Adobe PDF and HTML format every Monday and Thursday afternoon
for the duration of the sockeye field season beginning August
4th, 2011.
2011
FRASER SOCKEYE ESTIMATION PLAN
The
Fraser River Sockeye Stock Assessment Program has a mandate
to provide reliable escapement estimates for all Fraser River
sockeye populations. Individual populations are assessed using
standard enumeration methodology which is based on the number
of spawners expected to return by population. High precision
techniques such as enumeration fences, DIDSON (Dual Frequency
Identification Sonar) or mark-recapture studies are used for
stocks with expected escapements of 75,000+ (the actual technique
is based on local characteristics), and visual surveys are used
for stocks with expected escapements of less than 75,000. The
2011 plan is as follows:
- Mark-Recapture Studies:
Mark-recapture studies are planned for Upper Pitt River (Early
Summer), Adams River and Harrison River (Late Run populations).
- Enumeration Fences: Fences
are planned for Scotch Creek (Early Summer Run), Stellako
River (Summer Run); Cultus Lake and Birkenhead River (Late
Run).
- DIDSON projects:
DIDSON projects are planned for the Chilko River and Lake
aggregate and Horsefly River (Summer Run populations).
- Visual Surveys:
Cyclic visual surveys by foot, boat or helicopter are planned
for most remaining Fraser sockeye populations.
2011 FRASER SOCKEYE ESCAPEMENT REPORTING
Fraser sockeye spawning escapement
estimates are formulated and released in three steps:
Preliminary estimates
are based on data that have been entered into the computer database
at the completion of the field project. Data accuracy has not
been verified and bias tests have not been performed (mark-recapture
projects). Significant changes in preliminary estimates are
possible. The anticipated release schedule for Preliminary estimates
is: Early Run (Stuart) in late September; Early Summer Run in
mid October; Summer Run in late November; and Late Run in late
December.
Near Final estimates
are based on data that have been verified for accuracy and tested
for bias. Minor changes in near final estimates are likely.
Near Final estimates will be available for all run groups in
February 2012.
Final estimates are
released after all data have been incorporated into the analyses
and all verification steps have been completed. Final estimates
are not expected to be available for all run groups until late
2012.
Most
Current Escapement Update: [HTML]
[PDF]
Early Stuart Preliminary
Estimates [HTML]
[PDF]
Early Summer Preliminary
Estimates [HTML]
[PDF]
Summer Preliminary
Estimates [HTML]
[PDF]
Late Preliminary
Estimates [HTML]
[PDF]
2010 Near Final
Estimates: [HTML]
[PDF]
For
any inquiries about these reports please contact: Keri
Benner (250) 851-4864
For any inquiries regarding
historic data requests, please contact: Tracy
Cone (604) 666-7269
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