The primary source for this operating model is the 2014 stock assessment:
The OM rdata file can be downloaded from here
Download and import into R using myOM <- readRDS('OM.rdata')
Species: Hippoglossus hippoglossus
Common Name: Atlantic Halibut
Management Agency: DFO
Region: Atlantic 3NOPS4VWX5Zc
Latitude: -59
Longitude: 42.5
OM Name: Name of the operating model: Halibut_Atl_DFO
nsim: The number of simulations: 192
proyears: The number of projected years: 50
interval: The assessment interval - how often would you like to update the management system? 4
pstar: The percentile of the sample of the management recommendation for each method: 0.5
maxF: Maximum instantaneous fishing mortality rate that may be simulated for any given age class: 2
reps: Number of samples of the management recommendation for each method. Note that when this is set to 1, the mean value of the data inputs is used. 1
Source: A reference to a website or article from which parameters were taken to define the operating model
DFO. 2015. 2014 Assessment of Atlantic Halibut on the Scotian Shelf and Southern Grand Banks (NAFO Divisions 3NOPs4VWX5Zc). DFO Can. Sci. Advis. Sec. Sci. Advis. Rep. 2015/012
In order to generate the low initial stock size and subsequent rebuilding, it was necessary to use cpars to prescribe historical recruit deviations predicted by the assessment. This was done manually by making the initial cohort in 1970 very small (via the perr custom parameter).
maxage: The maximum age of individuals that is simulated (there is no plus group ). Single value. Positive integer
Specified Value(s): 60
Maximum age reported in Armsworthy and Campana 2010 was 50, added 10 years to this as there is no way in DLMtool to specify a “greater than” category. Adding 10 to the max age may allow for better calculation of the tail of the distribution.
R0: The magnitude of unfished recruitment. Single value. Positive real number
Specified Value(s): 100
Currently the operating model is scale-less and R0 is a nuisance parameter. An arbitrary value is used here.
M: Natural mortality rate. Uniform distribution lower and upper bounds. Positive real number
Specified Value(s): 0.14, 0.22
Lower value of M is taken from DFO 2015, but no confidence interval is presented. Upper value of M taken from den Heyer et al. 2013
M2: (Optional) Natural mortality rate at age. Vector of length maxage . Positive real number
Slot not used.
Mexp: Exponent of the Lorenzen function assuming an inverse relationship between M and weight. Uniform distribution lower and upper bounds. Real numbers <= 0.
Specified Value(s): 0, 0
Begin trials with age invariant M (likely a simplification)
Msd: Inter-annual variability in natural mortality rate expressed as a coefficient of variation. Uniform distribution lower and upper bounds. Non-negative real numbers
Specified Value(s): 0.08, 0.08
No SD for M in DFO 2015. SD for M of den Heyer et al. 2013 used.
Histograms of 48 simulations of M
, Mexp
, and Msd
parameters, with vertical colored lines indicating 3 randomly drawn values used in other plots:
The average natural mortality rate by year for adult fish for 3 simulations. The vertical dashed line indicates the end of the historical period:
Natural mortality-at-age for 3 simulations in the first historical year, the last historical year (i.e., current year), and the last projected year:
Natural mortality-at-length for 3 simulations in the first historical year, the last historical year (i.e., current year), and the last projected year:
h: Steepness of the stock recruit relationship. Uniform distribution lower and upper bounds. Values from 1/5 to 1
Specified Value(s): 0.4, 0.95
DFO 2015 states: “The stock-recruit relationship for halibut could not be well described by the more commonly used models”. Therefore, a broad range was used. Cox et al. 2016 used a value of 0.95, but this is likely an estimate as well.
SRrel: Type of stock-recruit relationship. Single value, switch (1) Beverton-Holt (2) Ricker. Integer
Specified Value(s): 1
The model predictions of Stock biomass and recruitment suggest that if anything the relationship is asymptotic, so Beverton Holt dynamics are assumed.
Perr: Process error, the CV of lognormal recruitment deviations. Uniform distribution lower and upper bounds. Non-negative real numbers
Specified in cpars: 0, 4.07
Standard deviation of log-recruitment reported by Cox et al. 2016.
AC: Autocorrelation in recruitment deviations rec(t)=ACrec(t-1)+(1-AC)sigma(t). Uniform distribution lower and upper bounds. Non-negative real numbers
Specified Value(s): 0.74, 0.74
Lag-1 autocorrelation is moderate, see recruitment deviation figure above.
Histograms of 48 simulations of steepness (h
), recruitment process error (Perr
) and auto-correlation (AC
) for the Beverton-Holt stock-recruitment relationship, with vertical colored lines indicating 3 randomly drawn values used in other plots:
Period: (Optional) Period for cyclical recruitment pattern in years. Uniform distribution lower and upper bounds. Non-negative real numbers
Slot not used.
Amplitude: (Optional) Amplitude in deviation from long-term average recruitment during recruitment cycle (eg a range from 0 to 1 means recruitment decreases or increases by up to 100% each cycle). Uniform distribution lower and upper bounds. 0 < Amplitude < 1
Slot not used.
Linf: Maximum length. Uniform distribution lower and upper bounds. Positive real numbers
Specified Value(s): 210.8, 287.9
Female values for Scotian Shelf and Grand Banks longline (which most closely matches the fishery) from Armsworthy and Campana 2010 used.
K: von Bertalanffy growth parameter k. Uniform distribution lower and upper bounds. Positive real numbers
Specified Value(s): 0.03, 0.09
Female values for Scotian Shelf and Grand Banks longline (which most closely matches the fishery) from Armsworthy and Campana 2010 used.
t0: von Bertalanffy theoretical age at length zero. Uniform distribution lower and upper bounds. Non-positive real numbers
Specified Value(s): -5.4, -0.76
Female values for the Grand Banks Scotian Shelf and longline (which most closely matches the fishery) from Armsworthy and Campana 2010 used.
LenCV: Coefficient of variation of length-at-age (assumed constant for all age classes). Uniform distribution lower and upper bounds. Positive real numbers
Specified Value(s): 0.05, 0.2
Estimated from values presented for females in Table 2 of Armsworthy and Campana 2010
Ksd: Inter-annual variability in growth parameter k expressed as coefficient of variation. Uniform distribution lower and upper bounds. Non-negative real numbers
Specified Value(s): 0, 0
Assume time-invariant
Linfsd: Inter-annual variability in maximum length expressed as a coefficient of variation. Uniform distribution lower and upper bounds. Non-negative real numbers
Specified Value(s): 0, 0
Assume time-invariant
Histograms of 48 simulations of von Bertalanffy growth parameters Linf
, K
, and t0
, and inter-annual variability in Linf and K (Linfsd
and Ksd
), with vertical colored lines indicating 3 randomly drawn values used in other plots:
The Linf and K parameters in each year for 3 simulations. The vertical dashed line indicates the end of the historical period:
Sampled length-at-age curves for 3 simulations in the first historical year, the last historical year, and the last projection year.
L50: Length at 50 percent maturity. Uniform distribution lower and upper bounds. Positive real numbers
Specified Value(s): 98, 108
Based on the female L50 value of 102.99 +/- 4.78 presented in Sigourney et al. 2006
L50_95: Length increment from 50 percent to 95 percent maturity. Uniform distribution lower and upper bounds. Positive real numbers
Specified Value(s): 15, 30
DFO 2015 states female maturity for 3NOPs4VWX at 119 cm, Sigourney et al. 2006 says L99 is 192.94 cm, and L75 is 129.07. Picked value of 15-30 cm sa intermediate between the 119 in DFO 2015 and the L75 of 129.07 from Sigourney et al. 2006.
Histograms of 48 simulations of L50
(length at 50% maturity), L95
(length at 95% maturity), and corresponding derived age at maturity parameters (A50
and A95
), with vertical colored lines indicating 3 randomly drawn values used in other plots:
Maturity-at-age and -length for 3 simulations in the first historical year, the last historical year (i.e., current year), and the last projected year:
D: Current level of stock depletion SSB(current)/SSB(unfished). Uniform distribution lower and upper bounds. Fraction
Specified Value(s): 0.08, 0.25
Cox et al. 2016 state D was 0.08 in 2013, my (WB) calculations for 2017 are 0.12. Try range of 0.08 to 0.25 (approx. 3 fold)
Figure from Cox et al. 2016
Fdisc: Fraction of discarded fish that die. Uniform distribution lower and upper bounds. Non-negative real numbers
Specified Value(s): 0.23, 0.23
Taken from study of Atlantic halibut trawl and longline discard mortality by Neilson et al. 1989
Histograms of 48 simulations of depletion (spawning biomass in the last historical year over average unfished spawning biomass; D
) and the fraction of discarded fish that are killed by fishing mortality (Fdisc
), with vertical colored lines indicating 3 randomly drawn values.
a: Length-weight parameter alpha. Single value. Positive real number
Specified Value(s): 0.01
Taken from Cox et al. 2016
b: Length-weight parameter beta. Single value. Positive real number
Specified Value(s): 3.12
Taken from Cox et al. 2016
Size_area_1: The size of area 1 relative to area 2. Uniform distribution lower and upper bounds. Positive real numbers
Specified Value(s): 0.5, 0.5
Set equal to area 2 - mixed stock assumption. Tagging data supports some long distance movement
Frac_area_1: The fraction of the unfished biomass in stock 1. Uniform distribution lower and upper bounds. Positive real numbers
Specified Value(s): 0.5, 0.5
Set equal to area 2 - mixed stock assumption. Tagging data supports some long distance movement
Prob_staying: The probability of inviduals in area 1 remaining in area 1 over the course of one year. Uniform distribution lower and upper bounds. Positive fraction.
Specified Value(s): 0.6, 0.9
High to moderate mixing - mixed stock assumption. Tagging data supports some long distance movement
Histograms of 48 simulations of size of area 1 (Size_area_1
), fraction of unfished biomass in area 1 (Frac_area_1
), and the probability of staying in area 1 in a year (Frac_area_1
), with vertical colored lines indicating 3 randomly drawn values used in other plots:
nyears: The number of years for the historical spool-up simulation. Single value. Positive integer
Specified Value(s): 44
The assessment on which the operating model is based, runs from 1970 - 2013, a total of 44 years.
Spat_targ: Distribution of fishing in relation to spatial biomass: fishing distribution is proportional to B^Spat_targ. Uniform distribution lower and upper bounds. Real numbers
Specified Value(s): 1, 1
No reason to assume that fishers do not fish in relation to CPUE
EffYears: Years representing join-points (vertices) of time-varying effort. Vector. Non-negative real numbers
EffLower: Lower bound on relative effort corresponding to EffYears. Vector. Non-negative real numbers
The fishing mortality rate trend presented in Cox 2016 is used here.
EffUpper: Upper bound on relative effort corresponding to EffYears. Vector. Non-negative real numbers
No uncertainty in F trend is assumed (variability in magnitude in F originates from the varying depletion and other parameters)
EffYears | EffLower | EffUpper |
---|---|---|
1970 | 0.405 | 0.405 |
1971 | 0.474 | 0.474 |
1972 | 0.473 | 0.473 |
1973 | 0.470 | 0.470 |
1974 | 0.398 | 0.398 |
1975 | 0.298 | 0.298 |
1976 | 0.228 | 0.228 |
1977 | 0.199 | 0.199 |
1978 | 0.170 | 0.170 |
1979 | 0.155 | 0.155 |
1980 | 0.135 | 0.135 |
1981 | 0.113 | 0.113 |
1982 | 0.136 | 0.136 |
1983 | 0.134 | 0.134 |
1984 | 0.181 | 0.181 |
1985 | 0.260 | 0.260 |
1986 | 0.261 | 0.261 |
1987 | 0.242 | 0.242 |
1988 | 0.323 | 0.323 |
1989 | 0.335 | 0.335 |
1990 | 0.427 | 0.427 |
1991 | 0.497 | 0.497 |
1992 | 0.473 | 0.473 |
1993 | 0.490 | 0.490 |
1994 | 0.445 | 0.445 |
1995 | 0.302 | 0.302 |
1996 | 0.252 | 0.252 |
1997 | 0.247 | 0.247 |
1998 | 0.199 | 0.199 |
1999 | 0.184 | 0.184 |
2000 | 0.156 | 0.156 |
2001 | 0.207 | 0.207 |
2002 | 0.205 | 0.205 |
2003 | 0.212 | 0.212 |
2004 | 0.198 | 0.198 |
2005 | 0.180 | 0.180 |
2006 | 0.182 | 0.182 |
2007 | 0.191 | 0.191 |
2008 | 0.168 | 0.168 |
2009 | 0.190 | 0.190 |
2010 | 0.146 | 0.146 |
2011 | 0.117 | 0.117 |
2012 | 0.108 | 0.108 |
2013 | 0.104 | 0.104 |
Esd: Additional inter-annual variability in fishing mortality rate. Uniform distribution lower and upper bounds. Non-negative real numbers
Specified Value(s): 0, 0
Since individual annual effort is prescribed above (e.g. EffLower) there is no need to inpose addition interannual variability.
Histograms of 48 simulations of inter-annual variability in historical fishing mortality (Esd
), with vertical colored lines indicating 3 randomly drawn values used in the time-series plot:
Time-series plot showing 3 trends in historical fishing mortality (OM@EffUpper
and OM@EffLower
or OM@cpars$Find
):
qinc: Average percentage change in fishing efficiency (applicable only to forward projection and input controls). Uniform distribution lower and upper bounds. Non-negative real numbers
Specified Value(s): 0.05, 0.1
No reason to suspect major changes in fishing efficiency.
qcv: Inter-annual variability in fishing efficiency (applicable only to forward projection and input controls). Uniform distribution lower and upper bounds. Non-negative real numbers
Specified Value(s): 0.05, 0.1
No reason to suspect high variability. Longline fishery.
Histograms of 48 simulations of inter-annual variability in fishing efficiency (qcv
) and average annual change in fishing efficiency (qinc
), with vertical colored lines indicating 3 randomly drawn values used in the time-series plot:
Time-series plot showing 3 trends in future fishing efficiency (catchability):
L5: Shortest length corresponding to 5 percent vulnerability. Uniform distribution lower and upper bounds. Positive real numbers
Specified Value(s): 55, 60
Estimated from Fig. 2 of Cox et al. 2016, and the mean length at age from Armsworthy and Campana 2010
LFS: Shortest length that is fully vulnerable to fishing. Uniform distribution lower and upper bounds. Positive real numbers
Specified Value(s): 65, 70
Estimated from Fig. 2 of Cox et al. 2016, and the mean length at age from Armsworthy and Campana 2010
Vmaxlen: The vulnerability of fish at Stock@Linf . Uniform distribution lower and upper bounds. Fraction
Specified Value(s): 1, 1
Asymptotic - selectivity modelled as knife-edged
isRel: Selectivity parameters in units of size-of-maturity (or absolute eg cm). Single value. Boolean.
Specified Value(s): FALSE
Selectivity and retention are modelled in absolute units and are not relative to length at maturity.
LR5: Shortest length corresponding ot 5 percent retention. Uniform distribution lower and upper bounds. Non-negative real numbers
Specified Value(s): 81, 81
Fishery has 81 cm minimum length
LFR: Shortest length that is fully retained. Uniform distribution lower and upper bounds. Non-negative real numbers
Specified Value(s): 81, 81
Fishery has 81 cm minimum length
Rmaxlen: The retention of fish at Stock@Linf . Uniform distribution lower and upper bounds. Non-negative real numbers
Specified Value(s): 1, 1
Assume all fish >=81 cm retained
DR: Discard rate - the fraction of caught fish that are discarded. Uniform distribution lower and upper bounds. Fraction
Specified Value(s): 0, 0
Due to value of fish, all fish above legal length are retained.
SelYears: (Optional) Years representing join-points (vertices) at which historical selectivity pattern changes. Vector. Positive real numbers
Slot not used.
AbsSelYears: (Optional) Calendar years corresponding with SelYears (eg 1951, rather than 1), used for plotting only. Vector (of same length as SelYears). Positive real numbers
Slot not used.
L5Lower: (Optional) Lower bound of L5 (use ChooseSelect function to set these). Vector. Non-negative real numbers
Slot not used.
L5Upper: (Optional) Upper bound of L5 (use ChooseSelect function to set these). Vector. Non-negative real numbers
Slot not used.
LFSLower: (Optional) Lower bound of LFS (use ChooseSelect function to set these). Vector. Non-negative real numbers
Slot not used.
LFSUpper: (Optional) Upper bound of LFS (use ChooseSelect function to set these). Vector. Non-negative real numbers
Slot not used.
VmaxLower: (Optional) Lower bound of Vmaxlen (use ChooseSelect function to set these). Vector. Fraction
Slot not used.
VmaxUpper: (Optional) Upper bound of Vmaxlen (use ChooseSelect function to set these). Vector. Fraction
Slot not used.
CurrentYr: The current calendar year (final year) of the historical simulations (eg 2011). Single value. Positive integer.
Specified Value(s): 2013
Last assessment year.
MPA: (Optional) Matrix specifying spatial closures for historical years.
Slot not used.
Cobs: Log-normal catch observation error expressed as a coefficient of variation. Uniform distribution lower and upper bounds. Non-negative real numbers
Specified Value(s): 0.05, 0.1
Relatively constrained catch over/under reporting - taken from Capelin example
Cbiascv: Log-normal coefficient of variation controlling the sampling of bias in catch observations for each simulation. Uniform distribution lower and upper bounds. Non-negative real numbers
Specified Value(s): 0.01
Expected to be low given size and value of fishery
CAA_nsamp: Number of catch-at-age observation per time step. Uniform distribution lower and upper bounds. Positive real numbers
Specified Value(s): 200, 225
Detailed otolith based CAA sampling has not been done lately. Took mean +/- 25 from Armsworthy and Campana 2010
CAA_ESS: Effective sample size (independent age draws) of the multinomial catch-at-age observation error model. Uniform distribution lower and upper bounds. Positive integers
Specified Value(s): 20, 25
Sampling in Armsworthy and Campana 2010 is unclear. Assume 10% of total samples taken in each independent sampling event.
CAL_nsamp: Number of catch-at-length observation per time step. Uniform distribution lower and upper bounds. Positive integers
Specified Value(s): 200, 225
No justification provided.
CAL_ESS: Effective sample size (independent length draws) of the multinomial catch-at-length observation error model. Uniform distribution lower and upper bounds. Positive integers
Specified Value(s): 20, 25
Same as CAA_nsamp: sampling in Armsworthy and Campana 2010 is unclear. Assume 10% of total samples taken in each independent sampling event.
Iobs: Observation error in the relative abundance indices expressed as a coefficient of variation. Uniform distribution lower and upper bounds. Positive real numbers
Specified Value(s): 0.2, 0.5
Based on Cal Iobs, 95% CI appears large; Capelin example calls 0.2-0.5 high for Btobs
Ibiascv: Not Used. Log-normal coefficient of variation controlling error in observations of relative abundance index. Uniform distribution lower and upper bounds. Positive real numbers
Specified Value(s): 0.1
Capelin example says this is unused
Btobs: Log-normal coefficient of variation controlling error in observations of current stock biomass among years. Uniform distribution lower and upper bounds. Positive real numbers
Specified Value(s): 0.2, 0.5
Based on Cal Btobs, 95% CI appears large; Capelin example calls 0.2-0.5 high for Btobs
Btbiascv: Uniform-log bounds for sampling persistent bias in current stock biomass. Uniform-log distribution lower and upper bounds. Positive real numbers
Specified Value(s): 0.33, 3
Taken from Capelin example
beta: A parameter controlling hyperstability/hyperdepletion where values below 1 lead to hyperstability (an index that decreases slower than true abundance) and values above 1 lead to hyperdepletion (an index that decreases more rapidly than true abundance). Uniform distribution lower and upper bounds. Positive real numbers
Specified Value(s): 0.33, 1
Taken from Capelin example
LenMbiascv: Log-normal coefficient of variation for sampling persistent bias in length at 50 percent maturity. Uniform distribution lower and upper bounds. Positive real numbers
Specified Value(s): 0.05
Taken from Capelin example
Mbiascv: Log-normal coefficient of variation for sampling persistent bias in observed natural mortality rate. Uniform distribution lower and upper bounds. Positive real numbers
Specified Value(s): 0.1
Natural mortality may be wrong, but these are a long-lived fish.
Kbiascv: Log-normal coefficient of variation for sampling persistent bias in observed growth parameter K. Uniform distribution lower and upper bounds. Positive real numbers
Specified Value(s): 0.05
Taken from Capelin example
t0biascv: Log-normal coefficient of variation for sampling persistent bias in observed t0. Uniform distribution lower and upper bounds. Positive real numbers
Specified Value(s): 0
Taken from Capelin example
Linfbiascv: Log-normal coefficient of variation for sampling persistent bias in observed maximum length. Uniform distribution lower and upper bounds. Positive real numbers
Specified Value(s): 0.05
Taken from Capelin example
LFCbiascv: Log-normal coefficient of variation for sampling persistent bias in observed length at first capture. Uniform distribution lower and upper bounds. Positive real numbers
Specified Value(s): 0.1
Taken from Capelin example
LFSbiascv: Log-normal coefficient of variation for sampling persistent bias in length-at-full selection. Uniform distribution lower and upper bounds. Positive real numbers
Specified Value(s): 0.1
Taken from Capelin example
FMSYbiascv: Not used. Log-normal coefficient of variation for sampling persistent bias in FMSY. Uniform distribution lower and upper bounds. Positive real numbers
Specified Value(s): 0.3
Taken from Capelin example
FMSY_Mbiascv: Log-normal coefficient of variation for sampling persistent bias in FMSY/M. Uniform distribution lower and upper bounds. Positive real numbers
Specified Value(s): 0.2
Taken from Capelin example
BMSY_B0biascv: Log-normal coefficient of variation for sampling persistent bias in BMSY relative to unfished. Uniform distribution lower and upper bounds. Positive real numbers
Specified Value(s): 0.05
Taken from Capelin example
Irefbiascv: Log-normal coefficient of variation for sampling persistent bias in relative abundance index at BMSY. Uniform distribution lower and upper bounds. Positive real numbers
Specified Value(s): 0.2
Taken from Capelin example
Crefbiascv: Log-normal coefficient of variation for sampling persistent bias in MSY. Uniform distribution lower and upper bounds. Positive real numbers
Specified Value(s): 0.2
Taken from Capelin example
Brefbiascv: Log-normal coefficient of variation for sampling persistent bias in BMSY. Uniform distribution lower and upper bounds. Positive real numbers
Specified Value(s): 0.4
Taken from Capelin example
Dbiascv: Log-normal coefficient of variation for sampling persistent bias in stock depletion. Uniform distribution lower and upper bounds. Positive real numbers
Specified Value(s): 0.5
Taken from Capelin example
Dobs: Log-normal coefficient of variation controlling error in observations of stock depletion among years. Uniform distribution lower and upper bounds. Positive real numbers
Specified Value(s): 0.05, 0.1
Taken from Capelin example
hbiascv: Log-normal coefficient of variation for sampling persistent bias in steepness. Uniform distribution lower and upper bounds. Positive real numbers
Specified Value(s): 0.3
Taken from Capelin example
Recbiascv: Log-normal coefficient of variation for sampling persistent bias in recent recruitment strength. Uniform distribution lower and upper bounds. Positive real numbers
Specified Value(s): 0.1, 0.2
Taken from Capelin example
Histograms of 48 simulations of inter-annual variability in catch observations (Csd
) and persistent bias in observed catch (Cbias
), with vertical colored lines indicating 3 randomly drawn values used in other plots:
Histograms of 48 simulations of inter-annual variability in depletion observations (Dobs
) and persistent bias in observed depletion (Dbias
), with vertical colored lines indicating 3 randomly drawn values used in other plots:
Histograms of 48 simulations of inter-annual variability in abundance observations (Btobs
) and persistent bias in observed abundance (Btbias
), with vertical colored lines indicating 3 randomly drawn values used in other plots:
Histograms of 48 simulations of inter-annual variability in index observations (Iobs
) and hyper-stability/depletion in observed index (beta
), with vertical colored lines indicating 3 randomly drawn values used in other plots:
Time-series plot of 3 samples of index observation error:
Plot showing an example true abundance index (blue) with 3 samples of index observation error and the hyper-stability/depletion parameter (beta
):
Histograms of 48 simulations of inter-annual variability in index observations (Recsd
) , with vertical colored lines indicating 3 randomly drawn values used in other plots:
Histograms of 48 simulations of catch-at-age effective sample size (CAA_ESS
) and sample size (CAA_nsamp
) and catch-at-length effective (CAL_ESS
) and actual sample size (CAL_nsamp
) with vertical colored lines indicating 3 randomly drawn values:
Histograms of 48 simulations of bias in observed natural mortality (Mbias
), von Bertalanffy growth function parameters (Linfbias
, Kbias
, and t0bias
), length-at-maturity (lenMbias
), and bias in observed length at first capture (LFCbias
) and first length at full capture (LFSbias
) with vertical colored lines indicating 3 randomly drawn values:
Histograms of 48 simulations of bias in observed FMSY/M (FMSY_Mbias
), BMSY/B0 (BMSY_B0bias
), reference index (Irefbias
), reference abundance (Brefbias
) and reference catch (Crefbias
), with vertical colored lines indicating 3 randomly drawn values:
TACFrac: Mean fraction of TAC taken. Uniform distribution lower and upper bounds. Positive real number.
Specified Value(s): 0.9, 1.1
Take about the TAC each year since 1998
TACSD: Log-normal coefficient of variation in the fraction of Total Allowable Catch (TAC) taken. Uniform distribution lower and upper bounds. Non-negative real numbers.
Specified Value(s): 0.02, 0.1
Fish within about 2-10% of TAC since 1998
TAEFrac: Mean fraction of TAE taken. Uniform distribution lower and upper bounds. Positive real number.
Specified Value(s): 0.9, 1.1
Year round fishery with TAC, effort invariant.Not applicable: year round fishery with TAC, effort is not used by management (the same values as TAC management are assumed however).
TAESD: Log-normal coefficient of variation in the fraction of Total Allowable Effort (TAE) taken. Uniform distribution lower and upper bounds. Non-negative real numbers.
Specified Value(s): 0.02, 0.1
Not applicable: year round fishery with TAC, effort is not used by management (the same values as TAC management are assumed however).
SizeLimFrac: The real minimum size that is retained expressed as a fraction of the size. Uniform distribution lower and upper bounds. Positive real number.
Specified Value(s): 1, 1
The minimum legal size is 81 cm, this is enforced
SizeLimSD: Log-normal coefficient of variation controlling mismatch between a minimum size limit and the real minimum size retained. Uniform distribution lower and upper bounds. Non-negative real numbers.
Specified Value(s): 0.01, 0.02
The minimul legal size is 81 cm, this is enforced
Histograms of 48 simulations of inter-annual variability in TAC implementation error (TACSD
) and persistent bias in TAC implementation (TACFrac
), with vertical colored lines indicating 3 randomly drawn values used in other plots:
Histograms of 48 simulations of inter-annual variability in TAE implementation error (TAESD
) and persistent bias in TAC implementation (TAEFrac
), with vertical colored lines indicating 3 randomly drawn values used in other plots:
Histograms of 48 simulations of inter-annual variability in size limit implementation error (SizeLimSD
) and persistent bias in size limit implementation (SizeLimFrac
), with vertical colored lines indicating 3 randomly drawn values used in other plots: