WHAT IS A TRUE MORTALITY FOR A RELEASED SALMON?

WHAT IS A TRUE MORTALITY FOR A RELEASED SALMON?

Back to Grays Harbor and the perception that the QIN and WDF&W do not get along. In communications obtained in Public Document Request ( PDR's )  it is very clear that staff from both work together rather well at the technical and preseason forecast level. In fact I would say compared to years back they have learned to accommodate each other's views reasonably well. Now as to harvest I cannot say so as harvest negotiations lack similar documentation as preseason documentation. Folks will have to draw their own conclusions.

 

Below is a e mail thread revolving around the Non Treaty Commercial Net release mortality developed early this year. I will highlight the portion that I find so interesting. The highlighted portion are QIN thoughts about release mortalities and in particular WDF&W's resistance to address the difference in survival of male & female. The QIN thoughts on female fish pretty much reflect what Chehalis brood stockers encountered with Chinook. This is important to Rec's as we do need true mortalities for C&R fisheries and the Commercials are asking that Rec mortality rates be reviewed also.  

 

The thing about mortalities is that it is all about location & timing. You get all over salmon in midst of transition from marine to fresh water and nothing good comes from it. The best guidance I was ever given was for Grays Harbor & Willapa  terminal fisheries  (  marine / tidal /  fresh  ) was this. Front of the bay fresh out of the ocean scales not set, low risk.  Scales set coloring up in tidal / marine and in transition is high risk in particular females. Slimed up in river is low risk and the risk decreases the closer one gets to the spawning reaches. In fact by the time salmon hit the hatchery ( or spawning grounds ) they are extremely durable and able to take substantial handling.  

As I do not edit e mail threads ( other than a private e mail addresses ) the formatting is a bit off but one can follow the thread so here you go:

 


-----Original Message-----
From: Scharpf, Mike M (DFW)
Sent: Monday, March 10, 2014 4:35 PM
To: Jorgensen, Jim
Cc: Thiesfeld, Steven L (DFW)
Subject: RE: web link for net mort rate and question about determining Hump
hatchery Coho strays

Good afternoon Jim,

 

Attached is the most up to date version of the Grays Harbor Planning Model.
We haven't discussed schedules at this time.  We've been worked for find and
correct computation and cell reference error.  We appreciate any input you
provide.

I will make sure that your comments of the net release mortality issues are
sent forward.

 

Mike


-----Original Message-----
From: Jorgensen, Jim
Sent: Monday, March 10, 2014 1:32 PM
To: Scharpf, Mike M (DFW)
Subject: RE: web link for net mort rate and question about determining Hump
hatchery Coho strays

Mike--

Is there a planning model for GH that you could provide me to review and
offer QIN proposed changes.

Also on the commercial net release mortality that the Mobrand group is
working, Steve suggested I should relay our technical information or issues
through you.

I would propose that the wild Coho brood stocking information from 1986 on
for the Hoh River is probably available through Roger Mosely.

The main point of this was that Roger and we found out that female Coho
taken from the lower Hoh and earlier in the season did not survive well at
all.

I think the lower and earlier ones all died, even though a good number
looked alive and well right up to before their eggs were to mature.

When checking them up to that time at a certain point we would find them
dead and their eggs having not separate from the skeins.  Males seemed to do
fine.

Therefore I would recommend that any release mortality be assessed from the
female survival perspective.  Coastal wild escapement estimates are based on
the number of reeds dug by females.

Any time/area situation in the lower freshwater area that had a similar
impact on female salmon, may render an overall survival rate of 50%, which
would be meaningless as far as achieving  escapement objectives.  One of the presenters in Olympia before the Mobrand group also cited their similar experiences brood stocking for what I believe was the Wishkah group.

Jim Jorgensen
________________________________________
From: Scharpf, Mike M (DFW) [
Raymond.Scharpf@dfw.wa.gov]
Sent: Thursday, February 27, 2014 1:30 PM
To: Jorgensen, Jim
Cc: Jurasin, Tyler; Hughes, Kirt M (DFW); Thiesfeld, Steven L (DFW)
Subject: RE: web link for net mort rate and question about determining Hump
hatchery Coho strays

Good question Jim,

I'll leave that up to Kirt or Steve to answer.


From: Jorgensen, Jim
Sent: Thursday, February 27, 2014 1:28 PM
To: Scharpf, Mike M (DFW)
Cc: Jurasin, Tyler
Subject: RE: web link for net mort rate and question about determing Hump
hatchery Coho strays

Mike-

Regarding the forum yesterday and the charge to Lars Mobrand and the other
panel members, are there avenues where QIN would be able to provide
technical information or recommendations to the panel?

Jim Jorgensen

From: Scharpf, Mike M (DFW) [
mailto:Raymond.Scharpf@dfw.wa.gov]
Sent: Thursday, February 27, 2014 1:04 PM
To: Jorgensen, Jim; Jurasin, Tyler
Cc: Gilbertson, Larry; Thiesfeld, Steven L (DFW)
Subject: web link for net mort rate and question about determing Hump
hatchery coho strays

Hi guys,

Below is the web link to all of the materials that have been presented to
the scientific panel that is evaluated the net release mortality rate.
Please enjoy.

http://wdfw.wa.gov/fishing/downloads/Settlement%20Workshop%20Materials/

Jim,

I have a question.  Do you know the origin of the estimated Humptulips
hatchery stray estimate?  In the GH coho forecast model in the run
reconstruction tab within the column labelled "Humptulips Hatchery Strays"
(column AQ) there is a comment that says "0.8 is applied to total escapement
est. for Humptulips, this calculation assumes that 20% of fish on spawning
grounds are of hatchery origin. Cannot calculate  w/o spawner surv. Data" .
First, this column multiplies the Humptulips escapement estimate by 0.8.
This produce is then used in the total HATCHERY escapement.  Seems that
multiplying by 0.8 is assuming that 80% of the spawners are hatchery origin.
I recall a discussion with Kirt about some CWT analysis that determined the
stray rate.  Do you have any recollection?   I'm trying to update all
documentation associated with forecasts.

Thanks for any help you can provide.