Modelling fine scale route choice of upstream migrating fish as they approach an instream structure

This study used pattern-oriented modelling (POM) to investigate the space use and behavioural response of upstream migrating European river lamprey (Lampetra fluviatilis) two-dimensional hydrodynamic conditions created by an instream structure (triangular profile gauging weir). Passive Integrated Transponder (PIT) acoustic telemetry were map spatial-temporal distribution patterns as they migrated upstream. Acoustic Doppler velocimetry computer quantify environment. In adherence with POM methodology, multiple movement models, incorporating increasingly complex environmental feedback mechanisms rules systematically assessed identify which factors might reproduce observed patterns. The best model was a spatially explicit Eulerian-Lagrangian Individual Based Model (IBM) that included two simple behaviours: 1) tortuous non-directed swimming when in low flow velocity (< 0.1 m s−1) 2) persistent directed (against flow) moderate high (≥ s−1). indicated heterogeneity important influence (i.e. separate behaviours velocity) sufficient main pattern observed: avoidance recirculating regions near banks. combination field telemetry, provided useful framework for identifying key (hydrodynamic behavioural) governed target species would likely work well investigating similar relationships other aquatic species.