A sneak peek at 2018 coho forecasts

Well... at least for those concerned about WILD fish.

https://wdfw.wa.gov/publications/01962/wdfw01962.pdf

I believe these are all based on PRE-harvest ocean adult equivalents.

I see that WDFW has another pie-in-the-sky wild coho forecast for GH... about 91K.

Curious to know just how cavernous the chasm will be between their forecast and the Quinault's?

Ah, the annual WAG contest... Always interesting; rarely accurate.

Without searching for pre-blob/drought years are these numbers (let alone hatchery returns) going to be tough to walk away from under the guise of Stilly Chinook conservation?


Puget Sound
Primary Units
Skagit River.............1,376,000..5.9%..81,184..99,994
Stillaguamish River.......337,000..4.5%..15,165....8,679
Snohomish River........1,984,000..4.5%..89,280..109,965
Hood Canal................359,000..7.6%..27,284...33,605
Straits of Juan de Fuca..184,000..4.0%...7,360.....9,065

The only number you need to pay attention to on each line is the THIRD one... pre-harvest adult recruitment.

Without actually knowing what the e-goals are, it looks to me like the Snohomish and Skagit have the best shot at harvestable surpluses to kill some wild coho outright as well as spending some as release mortalities to gain harvest access to hatch coho.

I'm quite surprised by the total Puget Sound numbers considering all the blob doom and gloom and early closures in 2015.
SF

I thought the Chehalis coho estimate seemed possible. When I look at the gill net harvest compared to the model I would guess that the 2017 actual total Chehalis coho run size will be about 44,000 compared with the model run size of 66,265.

The PDO temperature data for 2017 indicates that the ocean is becoming more favorable to survival. The Feb-May PDO in 2017 was 1.42 degrees cooler than in 2016. The correlation of PDO to run size would result in a line with an inverse slope of 36,000 fish per degree. The hedge is that there is a lot of variability and a broad confidence interval around the 36,000 fish value.

Based on this my own guess is a 2018 run size of 44,000 from last year plus 51,000 due to the improving PDO for a total run size estimate of 95,000.

I'm just a bit skeptical that the Chehalis is poised to lead the ENTIRE state in coho production.... edging out even the Snohomish, probably one of the most perennially productive wild coho basins we have.

If these forecasts actually materialize as predicted, I'll be jumping for joy as my expectation for chinook in my favorite basins isn't very good either.

Ah, but lest we forget, a better forecast means more scheduled commercial netting, which carries the risk of overharvest (and subsequent sport fishing closures) when the forecast doesn't materialize. The best years for the in-river crowd are the ones where they grossly underestimate the run. I love it when fish get "wasted."

For annual wild coho predictions see:
https://wdfw.wa.gov/conservation/research/projects/wild_coho/

From the 2014 Wild Coho predictions (https://wdfw.wa.gov/publications/01891/wdfw01891.pdf):

Primary Units
Skagit River...........1,409,000....7.0% ....98,630 ...121,482
Stillaguamish River.....237,000...11.0%....26,070 .....32,110
Snohomish River.....750,000...11.0%....82,500....101,615
Hood Canal..............490,000...10.0%....49,000......60,353

And for 2012:

Primary Units
Skagit River..............952,000...5.4%....51,400......63,300
Stillaguamish River.....370,000...8.7%....32,200......39,700
Snohomish River...1,000,000...8.7%....87,000....107,200
Hood Canal..............804,000...9.0%....72,400......89,100

And for 2010:

Primary Units
Skagit River............1,475,000....3.0%....44,300......54,500
Stillaguamish River......370,000....5.0%....18,500......22,800
Snohomish River...1,420,000....5.0%....71,000......87,500
Hood Canal...............995,000....3.2%....31,800......39,200

And to compare just the Snohomish:.........................................Post Season
2010.. Snohomish River.......1,420,000....5.0%....71,000......87,500....53.9
2012.. Snohomish River.......1,000,000....8.7%....87,000.....107,200...109.0
2014.. Snohomish River.........750,000...11.0%....82,500.....101,615...81.4
2015.. Snohomish River.......2,200.000....6.0%....82,677.....101,833...30.5
2016.. Snohomish River.......1,395,000....3.9%....54,504......67,010...N/A
2017.. Snohomish River.......2,025,000....5.3%...107,325.....132,191...N/A

2017.. Stillaguamish.............115,000....5.3%......6,095.......7,507...N/A
2018.. Snohomish River.......1,984,000....4.5%....89,280.....109,965
2018..Stillaguamish..............337,000....4.5%....15,165......18,679

If their smolt sampling and resulting numbers are reasonably accurate and using a reduced 4.5% return that 89K for 2018 looks pretty good; too bad they haven't augmented past projections with "actuals."

Edit: Added a couple years for the Snohomish and two years for the Stilly for which the good news is a healthy recovery from 2017 to 2018. Also, here are the wild versus hatchery comparables for years 2009-2017 on the Stilly and the Snohomish:

Snoho....2009..2010..2011...2012...2013...2014..2015...2016...2017
Natural...67.0..99.4..180.0..109.0..163.8..150.0..151.5..20.6..107.3
Hatchery.53.6...24.5...55.0....45.7..111.5...78.2...53.9..16.7... 62.0

Stilly
Natural...13.4..25.9...66.6.....47.5....33.3..32.5....31.3...2.8.....7.6
Hatchery...0.0...5.4.....0.6......4.1......3.1...6.0......0.0...0.0....1.5

Final Edit: Added the Post Season numbers for the years for which I had already established data sets where available. What I noticed was that the PFMC forecasts were often quite different than those of WDFW. Or I have seriously botched my reading of that info.

Larry -
You can find pre and post season run estimates in PFMC's pre-season report #1. Here is a link to the 2017 report

http://www.pcouncil.org/wp-content/uploads/2017/03/2017_Preseason_Report_1_03MAR17_final2.pdf

see page table III-4; pages 68/69 for the "S" rivers

Curt

http://www.pcouncil.org/wp-content/uploads/2017/03/2017_Preseason_Report_I_03MAR17_final2.pdf

I looked up the Grays Harbor numbers on that document. The forecast model is pretty worthless in our neck-o-da-woods.

The most recent 10 years with a full pre-post complement showed the forecast was achieved or exceeded half the time. In 3 of those 5, the actual return was nearly double the forecast.

The forecast failed to materialize as expected the other half of the time. In 3 of those 5, the forecast exceeded the actual return by a factor of OVER 2:1.... 2.2, 2.5, and 4.5-fold.

That's not to say GH isn't a phenomenal wild producer of coho... it most clearly can be ( ex nearly 200K wild coho in 2014). As can the Skagit and Snohomish systems.... all three have comparable potential to NATURALLY produce mega-runs of coho.

Thanks, but I couldn't find the actuals - maybe too much data (overload, overload...beep beep...blank screen).

Larry, for whatever reason, the link in Smalma's post only took me as far as the PFMC main site. The one in my post will take you directly to the actual PDF... scroll down to page 69 for that historic coho data.

You'll see that 2016 and 2017 are incomplete in that document, but I'm sure the updated 2018 document will be released any time now as the NOF/PFMC process kicks into high gear the next 2 weeks.

Thanks for that info; I was thinking I just couldn't figure it out.

Musta been quite the disparity cuz they ended up in "technical agreement" at 33-34K

I'm thinking the "dart they threw at the dartboard", was bent......

No way 2 agencies can be that far apart!!!!!!!

or maybe they need to have their eyes checked......

If the 2 agencies met, then all the figures should have been worked out.....I'm starting to think that very little time is spent with the QIN and WDFW working together on pre season figures....

I can't recall, but wasn't the Q's number pretty close last year, and the Department's off by many magnitudes?

Fish on...

Todd

Todd:

I think you are correct.

I just remember 2015......forecast was for "big return"....sport catch was 3 Coho in river, fish was good, early....not big fish but numbers were there for persons in right place.

Bay fishery, tribe, got fish....then NT started their fishery, not many fish.....WDFW shut EVERYTHING down, in October, Humptulips, Wynoochee, Chehalis, etc. There were legal fish to catch, chum and summer run on rivers that had fish.

WDFW did open the rivers in December.

Many people don't fish the Chehalis until the QIN and NT netters are done.....They lost out on any fishery.