CCAMLR Science Toolbox
www.ccamlr.org
Biological Parameters Estimation – R scripts
Age at maturity
Uses a logit-link binomial model to estimate age at 50% maturity.
Figure 1. Example of fitted logit-link binomial model to estimate age at
50% maturity. Dotted lines indicate the point in the model where 50% of
individuals are estimated to be mature, and the corresponding age. Size
of the points indicates the number of individuals of that age in the
data set.
Bayesian VBGF
Uses a Bayesian approach (using stan via brms) to fit a von Bertallanfy growth function (VBGF). Includes diagnostic plots and functions.
Figure 2. Example of a fitted VBGF on combined sex data. Blue = males,
red = females.
Figure 3. Example of diagnostic plots for the L_inf variable in the
fitted VBGF. Top left = density plot, top right = trace plot, bottom =
autocorrelation function barplot.
Length Weight
Fits an exponential curve to length-weight data.
Figure 4. Example of fitted exponential curve to length-weight data.