openpop_plot: An open population calculation function

In katherinekaplan/MPApopulationmodels: Population responses to marine protected areas (MPAs)

Description

This function calculates the ratio change abundance and biomass of a fished population, after a marine protected area is implemented assuming a population with external recruitment. The output is three plots, one with the deterministic ratio changes in abundance and biomass for fished age classes. The second is the abundance ratio change with stochastic recruitment. The third is the biomass ratio change with stochastic recruitment.

Usage

openpop_plot(tf, maxage, M, Fi, Lfish, Linf, k, a0, pW, qW, R, sig_r,
  simulations, MPAtime)

Arguments

tf:	the time steps to run the population
maxage:	max age of the species ie. number of age classes
M:	the natural mortality rate, if unknown generally use 0.2
Fi:	the fishing mortality rate, F, find in stock assessment if don't have more localized estimate
Lfish:	length at first capture in fishery
Linf:	asymptotic growth rate used in von-Bertallanfy growth equation
k:	von-bertallanfy growth parameter estimate
a0:	age at length zero used in von-Bertallanfy growth equation
pW:	weight length relationship parameter, same as a on fishbase.org but need to divide by 1000 to get in kg not grams
qW:	weight length relationship parameter, same as b on fishbase.org
R:	number of recruits to enter the population
sig_r:	stochastic parameter, log-normal distribution, around recruitment
simulations:	the number of simulations to run the population with stochastic recruitment
MPAtime:	the timestep that the MPA is implemented

Examples

openpop_plot(tf=50,M=0.2,Fi=0.14,Lfish=25,Linf=37.8,k=0.13,a0=-0.7,
maxage=25,pW=9.37e-06,qW=3.172,sig_r=0.3, R=500, MPAtime=1,simulations=100)

katherinekaplan/MPApopulationmodels documentation built on May 22, 2019, 8:51 p.m.