A complete set of performance statistics

A list containing a large number of performance statistics:

A list of key statistics used in fisheries management to evaluate the performance of management procedures. This is a long list that contains statistics that measure very similar outcomes, so a subset should be made of those most relevant to the management objectives of interest.

Usage

data(statistics)

statistics

Format

A named list with elements of class list, each containing three elements: a formula, a long name ('name'), and a description ('desc'), both of type 'character':

SB: SB: Mean spawner biomass
SB0: SB/SB[0]: Mean spawner biomass relative to unfished
minSB0: min(SB/SB[0]): Minimum spawner biomass relative to unfished
SBMSY: SB/SB[MSY]: Mean spawnwer biomass relative to SBMSY
F: F: Mean fishing mortality
Ftarget: F/F[target]: Mean fishing mortality relative to target
FMSY: F/F[MSY]: Mean fishing mortality relative to FMSY
green: P(Green): Probability of being in Kobe green quadrant
orange: P(Orange): Probability of being in Kobe orange quadrant
yellow: P(Yellow): Probability of being in Kobe yellow quadrant
red: P(Red): Probability of being in Kobe red quadrant
PSBMSY: P(SB>=SB[MSY]): Probability of SB greater or equal to SBMSY
PSBlim: P(SB>SB[limit]): Probability that spawner biomass is above SBlim
PSB20B0: P(SB > 0.20 %*% SB[0]): Probability that spawner biomass is above 20% SB0
risk1: mean(P(SB<B[limit])): ICES Risk 1, mean probability that spawner biomass is below Blim
risk2: once(P(SB<B[limit])): ICES Risk 2, probability that spawner biomass is above Blim once
risk3: max(P(SB>B[limit])): ICES Risk 3, max probability that spawner biomass is above Blim
C: mean(C): Mean catch over years
CMSY: C/MSY: Mean proportion of MSY
AAVC: AAV(C): Average annual variability in catch
IACC: IAC(C): Percentage inter-annual change in catch
PC0: P(shutdown): Probability of fishery shutdown, defined as catch less than 10% of MSY

A list containing named elements, each of which represents a specific statistic. Each of them contains:

formula: A formula defining how the metric is calculated.
name: A short descriptive name. This can contain plotmath() expressions to be parsed by plot functions.
desc: A more detailed description of the metric.

Details

Performance statistics are used by the performance() method to compute time series, or aggregates along time, of quantities of interest related to the result of applying a particular management procedure to an operating model. They combione FLCore::metrics() computed from the projected stocks, populations and fisheries, with biological, economic or other reference points, but can also use the results of calculations and decisions carried out by the MP.

Of the three elements in the list used to define each statistic, the first unnamed element, of class 'formula' is the one evaluated by performance(). The formula is evaluated with access to the reference points of the OM, contained in the refpts slot, a set of FLCore::metrics obtained from the projected OM, the contents of the tracking table with decisions and outputs from the MP internal calcultions, as well as any function available in the workspace.

The statistics currently included are:

SB: Spawner biomass in tonnes (\(SB\)), from the SB metric.
SB0: Spawner biomass relative to unfished (\(SB/SB0\)), requires the SB0 refpt.
minSB0: Minimum spawner biomass relative to unfished (\(min(SB/SB0)\)) requires the SB0 refpt..
SBMSY: Spawner biomass relative to \(SB[MSY]\) (\(SB/SB[MSY]\)) requires the SBMSY refpt..
R: Recruitment (\(R\)), from the R metric.
F: Fishing mortality (\(F\)), from the F metric.
Ftarget: Fishing mortality relative to target (\(F/F[target]\)) requires the Ftarget refpt.
FMSY: Fishing mortality relative to \(F[MSY]\) (\(F/F[MSY]\)) requires the FMSY refpt.
green: Probability of being in the Kobe green quadrant (\(P(Green)\)), requires the SBMSY and FMSY refpts.
orange: Probability of being in the Kobe orange quadrant (\(P(Orange)\)), requires the SBMSY and FMSY refpts.
yellow: Probability of bein, requires the SBMSY and FMSY refptsg in the Kobe yellow quadrant (\(P(Yellow)\)), requires the SBMSY and FMSY refpts.
red: Probability of being in the Kobe red quadrant (\(P(Red)\)), requires the SBMSY and FMSY refpts.
PSBMSY: Probability that spawner biomass is greater than or equal to \(SB[MSY]\) (\(P(SB>=SB[MSY])\)), requires the SBMSY refpt.
PSBlim: Probability that spawner biomass is above \(SB[lim]\) (\(P(SB>SB[lim])\)), requires the SBlim refpt.
PSB20B0: Probability that spawner biomass is above 20% of \(SB0\) (\(P(SB > 0.20 \%*\% SB0)\)), requires the SB0refpt.
risk1: ICES Risk 1: Probability that spawner biomass is below \(B[lim]\) (\(P(SB<B[lim])\)), requires the SBlim refpt.
risk2: ICES Risk 2: Probability that spawner biomass falls below \(B[lim]\) at least once (\(once(P(SB<B[lim]))\)), requires the SBlim refpt.
risk3: ICES Risk 3: Maximum probability that spawner biomass is below \(B[lim]\) (\(max(P(SB<B[lim]))\)), requires the SBlim refpt.
C: Catch in tonnes (\(C[t]\)), from the C metric.
CMSY: Proportion of maximum sustainable yield (\(C/MSY\)), requires the MSY refpt.
IACC: Percentage inter-annual change in catch (\(IAC(C)\)), from the C metric.
PIACC20: Probability that the inter-annual change in catch being less than 20% (\(P(IAC(C)<0.20)\)), from the C metric.
PC0: Probability of fishery shutdown (\(P(shutdown)\)), defined as catch falling below 10% of MSY, so requires the MSY refpt.

Examples

data(statistics)
# Access a specific statistic
statistics$SBMSY
#> [[1]]
#> ~SB/SBMSY
#> 
#> $name
#> [1] "SB/SB[MSY]"
#> 
#> $desc
#> [1] "Spawnwer biomass relative to SBMSY"
#>