Author(s): Hanna Jaspaert; Pieterjan Verhelst; Jan Baetens

Linked Author(s):

Keywords: Fish passage; Telemetry; State-space models; Particle filters

Abstract: Habitat fragmentation caused by anthropogenic structures—including weirs, pumping stations, shipping locks, and hydropower turbines—is a primary driver of the global decline in diadromous fish populations. Despite legislation and management efforts to restore these populations, the desired results are still to be reached. This project takes action on the urgent need to include data and knowledge -driven measures into water management in Flanders for diadromous species restoration. As traditional fishways are often insufficient, effective restoration of aquatic connectivity in highly regulated catchments demands a shift towards dynamic, adaptive management of the water-regulating structures themselves. This work presents the development of a novel, model-based decision support tool that moves beyond fixed physical passage solutions to enable smart regulation of existing infrastructure. It integrat es acoustic telemetry data, with the European eel (Anguilla anguilla) as a test species, and environmental variables with mechanistic modelling to estimate when fish want to migrate across a barrier and thus optimize the timing for water management opportunities. The core of the approach is the development and application of an Individual-Based Model (IBM) framework. This IBM is built on behavioural rules derived from state-space models which allow for the explicit incorporation of observation uncertainties. This IBM framework is applied for a free-flowing reference case and across two characteristic and highly regulated Flemish water systems: polder areas and canalized rivers.

DOI: https://doi.org/10.64697/iahr.proc.ise2026.abs.146

Year: 2026