INVESTIGADORES
Luis Cubillos Santander
Investigador Asociado Línea 3Somatic growth was studied in the Chilean hake stock off central coast of Chile, through the
application of Von Bertalanffy equation (vB) as a non-linear mixed effect model (NLME) on length-at-agedata
derived from otolith readings made at Instituto de Fomento Pesquero since 1972. Average growth rates
for each year from 1972 to 2009 were estimated. Growth parameters of vB curves were analyzed for three
major periods regarding changes in stock biomass (1972-1990, 1991-2003 and 2004-2009). Results indicated
that the average growth rate showed inter-annual variations that did not exceed ±15 cm of total length around
the historical average of males and females, showing no persistent tendency towards sustained increase or
decrease in somatic growth rate. Growth curves obtained with the vB parameters, estimated for the three
periods, showed a similar trajectories until age 7 and 8 years, in both male and females. Changes after this age
may be a result of a decrease of larger fish removed by the selective effect of fishing, which triggered
variations in the fitted curves, but not necessarily changes in somatic growth of these ages in the population.
The results demonstrated that the individual growth of hake has not changed significantly since 1972, without
observing a density-dependent effect with decreasing abundance.
