Combining green LiDAR bathymetry, aerial images and telemetry data to derive mesoscale habitat characteristics for European grayling and brown trout in a Norwegian river

Abstract While many studies provide microscale relationships between fish and habitat characteristics, covering longer river reaches are scarce. Modern remote sensing techniques may enable new effective ways of mapping assessing mesoscale characteristics. Using green LIDAR-derived bathymetry hydraulic modelling, we tested how depth velocity were related to counts adult European grayling ( Thymallus thymallus L.) brown trout Salmo trutta in 500 m sections three separate periods during the year. riverbank sinuosity from aerial images a Froude number-based index model as proxies for spatial heterogeneity, temporal correlations with section trout. Results showed that mean correlated period grayling. mixed analysis found significantly occurrence spawning. The results can be used assess flow-induced changes channel adjustments at level influence access use relevant habitats rivers occupied by