Emigrating Salmonid Habitat Estimation (ESHE): A Web-Based Tool for Estimating Habitat Needs for Outmigrating Juvenile Salmonids

A wealth of recent evidence has identified seasonally-inundated floodplains as providing quality food production and rearing habitat for juvenile Chinook salmon. Because studies have found that individual Chinook salmon maintain exclusive feeding territories even when schooling, territory size is thought to limit the density and production of juvenile Chinook salmon. Therefore, providing an adequate quantity and quality of rearing territory during emigration can reduce the negative effects associated with competition for space on a population level. We describe the creation of a deterministic simulation model that overlays modeled river hydrology with simulated cohorts of juvenile Chinook salmon, allowing for calculation of benefits provided by seasonally-inundated floodplain habitats. By tracking the movement, growth, and survival of juvenile Chinook salmon in a simulated system, we can provide estimates of rearing habitat needs in time and space, helping prioritize floodplain restoration locations. We will demonstrate a simple, generalizable online version of the simulation model that can be easily modified by users and customized for a particular watershed. We will also discuss model limitations and uncertainties and describe anticipated future modeling developments.