Description Usage Arguments Value Author(s)
Simulates MPA and surrounding fishing grounds. Growth is modeled with a discrete logistic growth model. This version assumes a closed population and no age structure. Organisms leaving the area through the right margin reincorporate the population through the left margin; same happens for uppper and lower margins.
1 2 |
area |
An N by M matrix with harvesting rates for fishing grounds (0 < harvesting rate <= 1) and MPAs (harvesting rate = 0) for the simulated area. |
nsteps |
Number of steps to run the simulation. |
r |
Population growth rate. |
pop0 |
Initial population size. If single, assumes equal population size across all cells in area. If a matrix, it must have the same dimensions as area. |
K |
Carrying capacity |
mrate |
Movement rate expressed as a proportion (relative to 1). Indicates the proportion of organisms that will move out of a cell in one timestep. |
op |
A logical value that indicates if a filled.contour is to be created. WARNING: op = TRUE may make the simulation slow. Alternatively, see closure.vec. |
cf |
A single integer that indicates the frequency (how many n steps) in which a closure to fishing occurs (i.e. no fishing). |
closure.vec |
a vector that contains all nsteps in which a closure must occur. For example, closure.vec=c(1,2,3,10) will close the fishery in yers 1,2,3 consecutively, and then again on nstep 10. |
results A list containing pop: a matrix of size N by M (same dimensions as area, above) with population size within each cell; and timeseries: a dataframe with 5 columns and nstep rows. The columns contain time (timeseries$time), population SIZE at each timestep (timeseries$pop), population DENSITY inside the MPA (timeseries$pop.in), population DENSITY outside the MPA (timeseries$pop.out) and yearly total catches (timeseries$total.catches).
Villasenor-Derbez, J.C.
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