mpa_sim: Spatial MPA simulation
In turfeffect/MPAtools: Tools to simulate and analyze no-take Marine Reserves

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	mpa_sim(area, nsteps, r, pop0, K, mrate, op = FALSE, cf = NULL, closure.vec = NULL)

`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.

turfeffect/MPAtools documentation built on June 1, 2019, 2:55 a.m.