Author(s): Sarah Broos; Ine S. Pauwels; David Buysse; Stijn Bruneel; Tom De Mulder; Gert Toming; Jeffrey A. Tuhtan

Linked Author(s): Tom De Mulder, Ine Pauwels

Keywords: Fish passage efficiency; Barotrauma Detection System (BDS); Fish backpack (FB); Fish behavior; River connectivity

Abstract: Archimedean screw are increasingly used for water level management and as hydropower installations to generate electricity, yet they act as significant barriers to fish migration. These infrastructures present a challenging "black box" because current monitoring methods, such as telemetry, are limited to fish entrance behaviour and fail to resolve fine-scale transit dynamics inside the screw. This work introduces a novel methodology to address this gap, investigating how high -resolution sensor technology can quantify fish passage efficiency and identify site-specific delays. The approach integrates two types of sensor: passive, neutrally buoyant Barotrauma Detection System (BDS) sensors and fish -mounted 'Fish Backpack' (FB) sensors, both equipped with pressure transducers and Inertial Measurement Units (IMUs). This enables the direct measurement of both hydrodynamic forces and movement responses during passage. By subdividing passage into 'entry' and 'transit' events, the methodology compares observed durations (Δt) between passive BDS and FB units to distinguish hydraulically-induced delays from active fish movements. This provides the ecohydraulics community with a robust tool to reveal internal processes within Archimedean screws, directly informing design optimizations to enhance aquatic connectivity in regulated catchments.

DOI: https://doi.org/10.64697/iahr.proc.ise2026.abs.233

Year: 2026