catch_advice

Calculates the advised catch using the SlotLim framework and (optionally) returns
a plot of the percentage change relative to <code>Cy</code> across a grid of
(<code>TBA</code>, <code>SAM</code>) values, with the output overlaid.

Catch advice for data-limited vertebrate and invertebrate
fisheries managed by harvest slot limits using the SlotLim harvest
control rule. The package accompanies the manuscript "SlotLim: catch advice
for data-limited vertebrate and invertebrate fisheries managed by harvest
slot limits" (Pritchard et al., in prep). Minimum data requirements: at
least two consecutive years of catch data, length–frequency distributions,
and biomass or abundance indices (all from fishery-dependent sources);
species-specific growth rate parameters (either von Bertalanffy, Gompertz,
or Schnute); and either the natural mortality rate ('M') or the maximum
observed age ('tmax'), from which M is estimated. The following functions
have optional plotting capabilities that require 'ggplot2' installed:
prop_target(), TBA(), SAM(), catch_advice(), catch_adjust(), and
slotlim_once().

C.J. Pritchard

SlotLim

Catch Advice for Fisheries Managed by Harvest Slot Limits

catch_advice function

<dl><dt>Cy</dt>
<dd>Numeric (length 1) &gt; 0. Most recent annual catch, or multi-year average.
If landing size restrictions have changed, use <code>catch_adjust</code> to adjust
the starting catch value accordingly.</dd>
<dt>TBA</dt>
<dd>Numeric (length 1) &gt; 0. Targeted Biomass Adjustment (see <code>TBA()</code>).</dd>
<dt>SAM</dt>
<dd>Numeric (length 1) &gt; 0. Size Adherence Multiplier (see <code>SAM()</code>).</dd>
<dt>T1</dt>
<dd>Optional numeric (length 1) in (0,1). Maximum allowed proportional
decrease. If <code>NULL</code>, no lower cap.</dd>
<dt>T2</dt>
<dd>Optional numeric (length 1) in (0,1). Maximum allowed proportional
increase. If <code>NULL</code>, no upper cap.</dd>
<dt>plot</dt>
<dd>Logical. If <code>TRUE</code>, return a ggplot2 heatmap (default <code>FALSE</code>).</dd></dl>

Arguments

catch_advice — catch_advice

<dl>

<dt>Cy</dt>
<dd>Numeric (length 1) &gt; 0. Most recent annual catch, or multi-year average.
If landing size restrictions have changed, use <code>catch_adjust</code> to adjust
the starting catch value accordingly.</dd>


<dt>TBA</dt>
<dd>Numeric (length 1) &gt; 0. Targeted Biomass Adjustment (see <code>TBA()</code>).</dd>


<dt>SAM</dt>
<dd>Numeric (length 1) &gt; 0. Size Adherence Multiplier (see <code>SAM()</code>).</dd>


<dt>T1</dt>
<dd>Optional numeric (length 1) in (0,1). Maximum allowed proportional
decrease. If <code>NULL</code>, no lower cap.</dd>


<dt>T2</dt>
<dd>Optional numeric (length 1) in (0,1). Maximum allowed proportional
increase. If <code>NULL</code>, no upper cap.</dd>


<dt>plot</dt>
<dd>Logical. If <code>TRUE</code>, return a ggplot2 heatmap (default <code>FALSE</code>).</dd>

</dl>

catch_advice: catch_advice

Description

Usage

Value

Arguments

See Also

Examples