An individual-based model for the migration of pike (Esox lucius) in the river Yser, Belgium

• First step towards an integrated spatially explicit model for describing pike populations in rivers.
• Calibration and validation of the individual-based model for pike in the river Yser, Belgium.
• It is shown how a trustworthy initial condition can be established from which the IBM is evolved.

For many decades, pike populations in Belgium have been suffering from a decline of the environmental quality due to habitat deterioration, water pollution and many other degrading phenomena. Since past attempts to rehabilitate the pike populations had only limited success, it is of importance to gain insight into the spatio-temporal dynamics of pike such that more effective restoration programs can be effectuated in the future. Ideally, this can be accomplished by relying on telemetry data, but since the collection of such data is both labour-intensive and costly, researchers often resort to a simulation-based approach, which on its turn requires a sound spatio-temporal model. Therefore, and as a first step towards an integrated individual-based model (IBM) for describing pike dynamics in rivers, an IBM mimicking the movement of pike in the river Yser, Belgium, is proposed in this paper. This model considers the specificities of pike, such as its seasonally dependent migration, swimming speed and habitat preference, and is based upon environmental data from the river Yser. It is shown that the in silico spatio-temporal dynamics coincides with the one that is typically inferred from in situ observations. Amongst other things, the proposed model may be relied upon to identify the most appropriate management and restoration measures through a scenario analysis.