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Fstd_SPR versus Fspr

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Laura Lee, modified 5 Years ago.

Fstd_SPR versus Fspr

Youngling Posts: 95 Join Date: 3/31/16 Recent Posts

Hi all-

I hope this is an easy question. I was wondering the difference between Fstd_SPR and Fspr in the report file. I'm wondering which is the appropriate one against which to judge stock status.

Thanks in advance!

Cheers,

Laura

KD
Kathryn Doering, modified 5 Years ago.

RE: Fstd_SPR versus Fspr

Youngling Posts: 57 Join Date: 2/19/19 Recent Posts

Hi Laura, 

 

I think it might be not as straight forward of an answer that you were hoping! Could you be more specific about where you see Fstd_SPR and Fspr in the report file? Could you also tell us what settings you are using for F in the starter file? That can determine what F values you see in the report file.

In the report file I am looking at, I only see an Fspr in the SPR/YPR_Profile  profile section:

Finish SPR/YPR profile
#Profile 0 is descending additively from max possible F:  3.19559
#Profile 1 is descending multiplicatively half of max possible F
#Profile 2 is additive back to Fcrash: 0.409691
#value 3 uses endyr F, which has different fleet allocation than benchmark
#value 4 is Fspr: 0.113449
#value 5 is Fbtgt: 0.0961308
#value 6 is Fmsy: 0.105357
#Profile 7 increases from Fmsy to Fcrash
#NOTE: meanage of catch is for total catch of fleet_type==1 or bycatch fleets with scaled Hrate
GLOBAL_MSY

Does it appear elsewhere in your report file?

As for Fstd_SPR, Rick is putting together a write-up on different F's in SS as there are many options in SS. Here is a snippet from that rough draft on the Fstd_* quantities (that will be renamed to Ann_F_* in 3.30.15):

Fstd_SPR (better named  Ann_F_SPR)
Ann_F is a single annual value of F across all fleets and areas according to specification of F_report_units,
 which is specified by users in the starter file.  If there are many fleets, across several areas, and 
with very different selectivity patterns, ann_F can have a complicated relationship to apical_F (H). 
F_reporting specification allows user to calculate it using H directly, use exploitation rate, or be
derived from Z at age.

Ann_F is also calculated in the benchmark calculations to provide equilibrium values that have the same units as annual_F.  Previous to version 3.30.15, it is labelled inaccurately as F_std in the output, not ann_F.  For example, in the Management Quantities section of derived quantities in the report file you will find:  
Fstd_Btgt 0.39009.  This is more accurately labelled as AnnF_Btgt in 3.30.15

 

Thanks,

Kathryn

Laura Lee, modified 5 Years ago.

RE: Fstd_SPR versus Fspr

Youngling Posts: 95 Join Date: 3/31/16 Recent Posts

I see Fstd_SPR in the Derived Quantities section in the report file and Fspr shows in the command prompt output and in the report file in the SPR/YPR_Profile section. In the starter file, I have selected 4 (true F for range of ages) for F_report_units. I have selected 0 (raw_F_report) for F_report_basis.

 

From: Kathryn Doering [mailto:VLab.Notifications@noaa.gov]
Sent: Thursday, February 6, 2020 1:36 PM
To: VLab.Notifications@noaa.gov
Subject: [External] [Stock Synthesis - SS] Fstd_SPR versus Fspr

 

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Hi Laura, 

 

I think it might be not as straight forward of an answer that you were hoping! Could you be more specific about where you see Fstd_SPR and Fspr in the report file? Could you also tell us what settings you are using for F in the starter file? That can determine what F values you see in the report file.

In the report file I am looking at, I only see an Fspr in the SPR/YPR_Profile  profile section:

 
Finish SPR/YPR profile
#Profile 0 is descending additively from max possible F:  3.19559
#Profile 1 is descending multiplicatively half of max possible F
#Profile 2 is additive back to Fcrash: 0.409691
#value 3 uses endyr F, which has different fleet allocation than benchmark
#value 4 is Fspr: 0.113449
#value 5 is Fbtgt: 0.0961308
#value 6 is Fmsy: 0.105357
#Profile 7 increases from Fmsy to Fcrash
#NOTE: meanage of catch is for total catch of fleet_type==1 or bycatch fleets with scaled Hrate
GLOBAL_MSY

Does it appear elsewhere in your report file?

As for Fstd_SPR, Rick is putting together a write-up on different F's in SS as there are many options in SS. Here is a snippet from that rough draft on the Fstd_* quantities (that will be renamed to Ann_F_* in 3.30.15):

Fstd_SPR (better named  Ann_F_SPR)
Ann_F is a single annual value of F across all fleets and areas according to specification of F_report_units,
 which is specified by users in the starter file.  If there are many fleets, across several areas, and 
with very different selectivity patterns, ann_F can have a complicated relationship to apical_F (H). 
F_reporting specification allows user to calculate it using H directly, use exploitation rate, or be
derived from Z at age.

Ann_F is also calculated in the benchmark calculations to provide equilibrium values that have the same units as annual_F.  Previous to version 3.30.15, it is labelled inaccurately as F_std in the output, not ann_F.  For example, in the Management Quantities section of derived quantities in the report file you will find:  
Fstd_Btgt 0.39009.  This is more accurately labelled as AnnF_Btgt in 3.30.15

 

Thanks,

Kathryn


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Kathryn Doering Stock Synthesis Virtual Lab Forum https://vlab.noaa.gov/web/stock-synthesis/public-forums/-/message_boards/view_message/8945673 VLab.Notifications@noaa.gov