Individual‐based modelling of hydropeaking effects on brown trout and Atlantic salmon in a regulated river

We developed an individual-based model (IBM) to understand the effects of hydropeaking on growth, survival and distribution age 0+ 1+ juveniles for high-conservation value populations native brown trout (Salmo trutta) Atlantic salmon (S. salar) in river Gullspång, Sweden. parameterized applied inSTREAM (7.2-SD) calibrated by comparing predicted versus observed growth under current regime (n=>1,200 fish 365 days). Our objective was flow scenarios with without hydropeaking. that generally resulted modest (~10%) negative both species. Survival more affected than smaller larger fish. On-peak (high) flows less profitable feeding conditions (less growth) higher predation (lower survival). Thus, 7.2-SD appears capture ecologically-relevant behavioral patterns hydropeaking, example, habitat selection, response rapid changes. Understanding such large rivers via manipulative field studies, even if possible, would be time-consuming costly. study demonstrates potential IBMs as powerful tools testing research questions assessing prioritizing alternative management strategies regulated rivers.