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add Brian's suggested edits
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e-perl-NOAA committed May 2, 2024
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2 changes: 1 addition & 1 deletion 13output.tex
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Expand Up @@ -104,7 +104,7 @@ \subsubsection{F std}
\item 2 = exploitation(Num)
\item 3 = sum(Frates)
\end{itemize}
The exploitation rates are calculated as the ratio of the total annual catch (in either biomass or numbers as specified) to the summary biomass or summary numbers on January 1. The sum of the F rates is simply the sum of all the apical Fs. This makes sense if the F method is in terms of instantaneous F (not Pope's approximation) and if there are not fleets with widely different size/age at peak selectivity, and if there is no seasonality, and especially if there is only one area. In the derived quantities, there is an annual statistic that is the ratio of the can be annual F\_std value to the corresponding benchmark statistic. The available options for the denominator are:
The exploitation rates are calculated as the ratio of the total annual catch (in either biomass or numbers as specified) to the summary biomass or summary numbers on January 1. The sum of the F rates is simply the sum of all the apical Fs. This makes sense if the F method is in terms of instantaneous F (not Pope's approximation) and if there are not fleets with widely different size/age at peak selectivity, and if there is no seasonality, and especially if there is only one area. In the derived quantities, there is an annual statistic that is the ratio of the annual F\_std value to the corresponding benchmark statistic. The available options for the denominator are:
\begin{itemize}
\item 0 = raw
\item 1 = F/F\textsubscript {SPR}
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2 changes: 1 addition & 1 deletion _f_mortality.tex
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Expand Up @@ -95,7 +95,7 @@ \subsection{Fishing Mortality in Stock Synthesis}

Yr Seas Seas\_dur F\_std annual\_F annual\_M <each fleet's F\_scalar>

In this table, the displayed value for annual\_F will be from the $F=Z-M$ method regardless of which option was chosen for F\_std. If F\_std uses option 4 or 5, then the annual\_F will use the same range of ages. Otherwise, annual\_F will be for the age that is the mid-age of the age range.
In this table, the displayed value for annual\_F will be from the $F=Z-M$ method regardless of which option was chosen for F\_std. If F\_std uses option 4 or 5, then the annual\_F will use the same range of ages. Otherwise, annual\_F will be for the age that is the mid-age of the age range of the model.

% While F is a simple concept in a biomass dynamics model with a single fishing fleet, the concept of "F" as a single number is very incomplete when there are multiple fleets, some with length-based and/or dome-shaped selectivity. In SS3, the F multiplier is multiplied first by fleet-specific relative F's to get the F for each fleet, then that fleet-specific F is multiplied by the age-selectivity to get F at age. Depending on the choice of selectivity pattern, these age-specific F's may or may not peak at 1.0 and can even exceed 1.0 in some circumstances. The realized F-at-age for each fleet is (F multiplier) * (relative F) * (age-selectivity). You can see the results in the F\_AT\_AGE section of the Report file.

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