Atlantis operating model equations
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| D.2 Effort
The effort coefficient mFC,FX can be calculated in a number of ways, ranging from prescribed effort matrices to dynamic processes (such as basing all effort allocation on past catches or making minor modifications to long term trends of effort distribution based on recent catches in each area) and is given by one of the following equations. If effort is a temporally prescribed constant (i.e. effort per quarter is fixed):  (D.4)
where  is the proportion of the current quarter of the year which has already passed, mDj,qrt,FX is the effort of fishery FC in the qrt quarter of the year. This value can be used as is (i.e. homogeneously distributed across all cells) or spatially weighted based on the CPUE from previous time step. If the spatial distribution of the effort is prescribed rather than the temporal component then the equation used is the same as for (D.4) but with mDqrt,FX replaced with mDj,qrt,FX the effort of fishery FC in cell j in quarter qrt.
If the effort distribution is calculated dynamically then mFC,FX in cell j time t is given by:  (D.5)
where the ideal new distribution meff,t,j given by:  (D.6)
with FC,max is maximum allowable effort and BCPUE,j is the CPUE in the cell in the previous time step and the velocity Fvel is based on the distance between cells (if CPUE based only) or the distance to the ports if using a fleet dynamics model. The equations (D4) to (D6) are used for the commercial fleets, but the recreational fishery is represented in a slightly different way:  (D.7)
where Npop,k is the population in port k, pop is the proportion of the population that fishes recreationally, Frecvel is the velocity of recreational vessels based on distances to port, and mDj,qrt,FX the effort of the recreational fishery in cell j in quarter qrt (usually used to constrain recreational and charter-boat effort to coastal cells). If the effort displacement option is being used then if the total effort for a fishery would drop using any of these dynamic formulations (either due to the imposition of MPAs or declining stocks) then the difference in each area is redistributed to the adjacent cells with the greatest biomass of the target groups. Directory: content -> suppl -> 2013 suppl -> Torres-Miranda et al. American Journal of Botany suppl -> Assessment of the acoustic telemetry positioning system suppl -> Additional File 1 Text summary suppl -> Additional file 5, Table costs and ccdss process-related outcomes for trials of acute care management a suppl -> Supplementary Notes and Figures 2013 -> Metal Application 2013 -> Genomic erv make-ups used in phylogenetic analyses 2013 -> Table specimens used for dna sequencing Download 2.6 Mb. Share with your friends:
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