Formatting is screwed but here are the GH Chinook & Coho forecast.

MEMORANDUM

TO: Wendy Beeghley, Angelika Hagen-Breaux, Aaron Default, Marlene Bellman

FROM: Mike Scharpf and Tyler Jurasin

Date: March 3, 2017

SUBJECT: 2016 Grays Harbor Pre-Season Forecasts

Grays Harbor Spring Chinook: 1,277 terminal runsize
Recruit ages 3, 4, 5, and 6 are predicted using a five-year average recruits per spawners.
All are unmarked.

Brood Year 3 yo – 2014 4 yo – 2013 5 yo – 2012 6 yo – 2011 Total
Chehalis 305 720 248 4 1,277



Grays Harbor Natural Coho: 50,043 Ocean Age three recruits (Chehalis River = 41,305 and Humptulips River =6,862), South Bay Tribs = 1,876
The forecast of Chehalis wild Coho was developed using the model Ocean Recruits ~ PDO and maximum one-day September upwelling index . Final Model: Log Recruits ~ bo + b1* mean (mean(PDO i = 3, j = Mar-Jul) + b2*Upwelling i = 3, Max one day September, 125W 48N. The Humptulips and South Bay tributary forecasts are based on recruit densities scaled from Clearwater and Chehalis basins, respectively.

Grays Harbor Hatchery Coho: 36,355 Ocean Age three recruits (Chehalis River = 25,964 and Humptulips River = 9,179, Grays Harbor Net Pens = 1,212

Forecasts were based on recent 10 year average return/smolt rates (excluding 2 highest return rates) expanded to ocean age 3 recruits.

Total Marked Total Unmarked
Chehalis 19,860 6,104
Humptulips 9,075 104
GH net pen 1,178 34


Grays Harbor Fall Natural Chinook: 16,192 terminal runsize (Chehalis River = 10,351 and Humptulips River = 5,841)

Based on a ten-year average recruits per spawn for age 3 and age class relationships determined from log linear regressions for 4 year olds on 2 and 3 year olds, and 5 year olds on 2, 3, and 4 year olds for all stocks, and 6 year olds on 5 year olds for Chehalis and Humptulips.

Brood Year 3 yo – 2014 4 yo – 2013 5 yo – 2012 6 yo – 2011 Total
Chehalis 1,141 4,130 4,988 92 10,351

Humptulips 439 1,861 3,403 138 5,841



Grays Harbor Fall Hatchery Chinook: 5,631 terminal runsize (Chehalis River = 2,425 and Humptulips River =3,207)
Based on a ten-year average recruits per spawn for age 3 and age class relationships determined from log linear regressions for 4 year olds on 2 and 3 year olds, and 5 year olds on 2, 3, and 4 year olds for all stocks, and 6 year olds on 5 year olds for Chehalis and Humptulips.

Chinook Marked / Unmarked Information

Chehalis River
Brood Year 3 yo – 2014 4 yo – 2013 5 yo – 2012 6 yo – 2011 Total
2016 Forecast 310 815 1,247 53 2,425

Mark Rate 99.01% 99.96% 99.46% 98.66%
Marked 307 815 1,240 52 2,414

Unmarked 3 0 7 1 11



Humptulips River
Brood Year 3 yo – 2014 4 yo – 2013 5 yo – 2012 6 yo – 2011 Total
2016 Forecast 287 816 2,041 63 3,207

Mark Rate 99.12% 99.26% 98.87% 98.19%
Marked 284 810 2,018 62 3,174

Unmarked 3 6 23 1 33


Grays Harbor Chum: 31,300 terminal run size (Naturals 30,100, hatchery origin 1,200)
Based on a five-year average recruits per spawners.

Brood Year 3 yo – 2014 4 yo – 2013 5 yo – 2012
Grays Harbor 3,619 16,382 11,380