Here is the Grays Harbor preseason salmon forecast. Formatting is off as I had to convert it to word which throws things off a bit. Last night preseason forecast meeting was a productive one I think but I did notice one thing, damn we are getting old! Those who attended were the same folks that followed and participated in NOF for years. You know on this thread and in general lots of bitching but the bitchers didn't participate. If one thinks a email to staff saying I want to kill a fish is as good as actually participating in the process you would be wrong.


SUBJECT: 2023 Grays Harbor Pre-Season Forecasts-Spring Chinook, fall Chinook, Coho, Chum

Grays Harbor Spring Chinook: 1,232 terminal runsize
Forecast is based on the geometric mean for three-year-old brood year count by age for the last 10 years along with last 10 years average not adjusted for brood performance for the four-, five- and six-year-olds. All are unmarked.

Brood Year 3 yr – 2020 4 yr – 2018 5 yr – 2017 6 yr – 2016 Total
Chehalis 352 817 61 1 1,232


Grays Harbor Natural Coho: Ocean Age three recruits 102,841 (Chehalis River = 92,432 and Humptulips River = 6,212, South Bay Tribs = 4,197
An Ocean Age 3 (OA3) Coho marine survival prediction is applied to Grays Harbor smolt production estimates. The OA3 marine survival prediction uses QDFi prediction of Queets coho January Age 3 marine survival and divides it by the natural mortality rate of 1.23169. The Chehalis wild Coho smolt estimates was developed scaling the 2022 Queets River natural Coho smolt production to the Chehalis River production based on the relationship between the Backward FRAM January Age 3 ocean abundances of Queets and Chehalis natural Coho adult abundances during the past 15 years. Humptulips and South Bay tributary smolt estimates are based on recruit densities scaled from Clearwater and Chehalis basins, respectively.

Grays Harbor Hatchery Coho: 111,430 Ocean Age three recruits (Chehalis River = 80,672 and Humptulips River = 26,073, Grays Harbor Net Pens = 4,685

Forecasts were based on recent 3-year average terminal return/smolt release rates scaled by current hatchery rack returns per release compared to the past five-year average, expanded to Ocean Age 3 recruits based on Bingham Creek hatchery tag recoveries for broodyear released 2013-2016 (most recent full complement of tag code recoveries)(9.81% of the tags recovered per-terminally).

Total Marked Total Unmarked
Chehalis 76,694 3,978
Humptulips 25,935 138
GH net pen 4,685 0


Grays Harbor Fall Natural Chinook: 15,006 terminal runsize (Chehalis River = 10,828 and Humptulips River = 4,178)

The forecast is based on a five-year average geometric mean returns for age 3s, 5s, and 6s, while age 4 forecast is based on a linear relationship of recruits per spawner of age 2 plus age 3s to age 4 recruits per spawner. Humptulips age 5s is based on a 10-year average linear relationship of recruits per spawner between age 4s to age 5s.

Brood Year 3 yr – 2020 4 yr – 2019 5 yr – 2018 6 yr – 2017 Total
Chehalis 1,872 6,942 1,967 47 10,828
Humptulips 631 2,364 1,176 7 4,178

Grays Harbor Fall Hatchery Chinook: 5,922 terminal runsize (Chehalis River = 1,196 and Humptulips River = 4,726)

Hatchery forecasts for both stocks are based on the same methods. For age 3, a ten-year average recruits per release is applied to the 2020 smolt releases. Age 4 returns are based on the age class relationships determined from log linear regressions for 4-year-olds returns per release to 2- and 3-year-olds returns per release for broodyears 1991 to 2019, applied to the 2022 age 2 and 3 return value. Age 5 method is similar to age 4 but uses the relationship between age 5 returns per release and age 4 return per release for broodyears 1991 to 2017 than applied to the 2022 age 4 return value. Forecast for age 6 fish is based on the most recent mean 5-year return per release for 6-year-olds adjusted by brood performance of the most recent age 5 return per release as it relates to the previous 5-year average return per release.

Chinook Marked / Unmarked Information

Chehalis River
Brood Year 3 yr – 2020 4 yr – 2019 5 yr – 2018 6 y – 2017 Total
2023 Forecast 378 518 299 1 1,196
Mark Rate 0.983 0.998 .953 1.00
Marked 372 517 285 1 1,175
Unmarked 6 1 14 0 21

Humptulips River
Brood Year 3 yr – 2020 4 yr – 2019 5 y – 2018 6 y – 2017 Total
2023 Forecast 824 2,868 1,032 2 4,726
Mark Rate 0.994 0.993 0.992 0.993
Marked 819 2,848 1,024 2 4,693
Unmarked 5 20 8 0 33




Grays Harbor Chum: 53,519 terminal run size (Naturals 51,976 hatchery origin 1,543)

The wild chum forecast utilizes the relationship of recruits per spawner for 3-year-olds (Broodyears 2000-2019) to the NPGO (Jan-March) 2000-2019 to predict the 3-year-old component. Selection to use NPGO over last year’s use of the Upwelling Anomaly was due to a more consistent model performance over time. The 4-year-old component in forecasted using the last five years average recruits per spawner applied to the 2019 escapement.
Sibling relationship between 3-year and 4-year-olds is poor and model performance using ocean variable was inconsistent. The 5-year-old component is predicted using a 5-year average recruits per spawner adjusted by brood performance of 4-year-olds. There is a survival relationship between 4-year-old chum and the following year 5-year-old that is not seen between the 3s and 4s. The use of marine variables was not as consistence over time as a sibling based forecast model.
Hatchery component forecast is based on the most recent 5-year mean return/release.

Grays Harbor wild and hatchery forecasts
Brood Year 3 yr – 2020 4 yr – 2019 5 yr – 2018 Total
Wild 19,658 30,990 1,328 51,976
Hatchery 422 894 227 1,543