about me



simulation type dynamic simulation based on a continuous model
domain Fishery Management
target group University
duration 2 days
model Van Densen and Pet (1988)
publisher University of Wageningen, Dept. of Aquaculture and Fisheries
year 1989
platform MS-DOS
design system/ engine Thesis (MS-DOS)
my connection educational advise and supervision


PERCH simulates the population dynamics of Perch in Lake IJssel.

With the simulation program PERCH students can study the effects of several management measures (increasing or decreasing the fishing effort, changing efficiency and mesh size of the nets, adjusting the close season) on the distribution of the catch and on the structure of the population of a single fish species under conditions of gill net fishery. It is hard to understand the mutual dependency on the effects of these measures when the concepts are taught in a purely theoretical way.

PERCH allows the students to build a conceptual model of the relations in the Lake IJssel system and to adjust this model to concrete experience gained by active experimentation. By means of induction students will generalize from the specific case of Lake IJssel to more general concepts of fishery management. The conceptualization of these general concepts may help students specializing in fishery management to solve other fishery problems which they may meet in their future careers.

During simulation 30 screens with dynamic graphic output are available. Four examples are shown in the figure above. (a. length-frequency distribution of the standing stock; b. length-frequency distribution in the standing stock and in the catch in each age class; c. time registrations of biomass; d. time registrations of mean length and deviation of the mean in 7 year old Perch).

Apart from courses of fishery management PERCH can also be used in more general university biology courses like courses of population dynamics or courses of nature management. In these courses PERCH may be used as an example for the way modelling techniques are applied in fishery management and in nature management in general.

PERCH, an educational computer simulation of a fish population