InSTREAM 7: Instream flow assessment and management model for stream trout

Abstract

Mechanistic, individual-based simulation models have been used for >25 years to overcome well-known limitations of "habitat suitability" models. InSTREAM 7 is the latest of our individual-based models for predicting the effects of flow and temperature regimes on stream salmonid populations. Unlike PHABSIM (or other methods based on habitat "quality," e.g., as net rate of energy intake), inSTREAM mechanistically represents specific effects of flow and temperature on all life stages, and how those effects combine into testable predictions of population measures such as abundance, relative abundance of multiple trout species, and persistence. InSTREAM 7 is the first version to also represent the daily light cycle (dawn, day, dusk, and night) and how feeding, predation risk, and individual behavior vary among light phases. An example assessment illustrates the importance of inSTREAM's multiple mechanisms: predicted trout population response to flow and temperature regimes depended on the effects of sub-lethal temperatures on feeding behavior and effects of temperature on egg survival and development, as well as how depth and velocity affected growth and predation risk. While its input data requirements are comparable to PHABSIM's, inSTREAM provides a more comprehensive framework for thinking about and predicting specific, well-known effects of flow and temperature. It has also proven useful for designing and evaluating restoration projects and for prioritizing alternative management actions. InSTREAM 7 is free, open-source, completely updated with recent literature, and implemented in the popular NetLogo software platform that makes customization easy.

Quantifying the Foodscape for Stream‐Dwelling Cutthroat Trout Reveals Spatial and Temporal Ranges of Resource Exploitation and Energy Intake

“…Studies to evaluate the effect of restoration efforts or predict future consequences of climate change are commonly based on the availability of suitable habitat for salmonid fishes (Jenkins and Keeley 2010;Urabe et al 2010;Carmichael et al 2020;Railsback et al 2021b). At the core of many such models, fish foraging behavior and estimates of food consumption are used to calculate energy intake and habitat suitability (Hughes and Dill 1990;Rosenfeld and Taylor 2009;Dodrill et al 2016;Hayes et al 2016;Railsback et al 2021a). Despite the importance of behavior in estimating foraging location, food intake, and constraints of when fish can forage, relatively few behavioral data have been used to parameterize models.…”

“…2016; Railsback et al. 2021a). Despite the importance of behavior in estimating foraging location, food intake, and constraints of when fish can forage, relatively few behavioral data have been used to parameterize models.…”

Growth and mortality of sympatric Atlantic salmon and brown trout fry in fluctuating and stable flows

“…inSTREAM, Railsback et al, 2009). Such IBMs can be valuable tools for examining the consequences of alternative scenarios related to physical restoration projects and different flow regimes, for instance, how salmonid populations are affected by sub‐daily fluctuations (Hajiesmaeili et al, 2022; Railsback et al, 2021). Further development of these IBMs may also benefit from species‐specific parameters (e.g.…”

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

“…InSTREAM 7 is a major revision of inSTREAM, with updates in the model formulation and new software in the popular NetLogo platform (Railsback, Ayllón, & Harvey, 2021).…”