Smolt-to-Adult Ratio (SAR) estimates for CWT Methods
The method for calculating Smolt-to-Adult Ratio (SAR) estimates for CWT is based on:
Skalski J.R., and R.L. Townsend. 2005. Pacific Northwest Hatcheries Smolt-to-Adult Ratio (SAR) Estimation using Coded Wire Tags (CWT) Data. Technical Report to Bonneville Power Administration, Project No. 1991-051-00, Contract No. 00013690.
Definitions
- Excluded from returns: SAMPLE_TYPE 5 = Voluntary or select recoveries from a sampled fishery with known catch and no awareness estimates available; use of these recoveries leads to double counting.
- Brood Year: Calendar year when majority of parents of the
fish in the release group spawned.
- Tag Code: Unique identifier for a release group.
- End Release Date: Last date of release for the release group.
- Number Released: Total number tagged with CWT corrected for
tag loss and tagging mortality.
- Estimated Returns (Total
)
: Estimate of the total CWTs recovered for a release
group, taking into account the subsampling process of examining fish
for tags.
- SAR: Estimate of smolt-to-adult ratio. In a generalized
form, SAR is proportional to
/ R (number released). Release size weighted SAR presented for Brood Year; Equation 10 from Skalski and Townsend, 2005. Standard error calculated from SAR varianced weighted by release size, Equation 11.
- Singles: 'Y' indicates that the SAR includes returns with no sample size and the SAR value is a minimum estimate.
- * Incomplete Data.