Managing flows for sockeye salmon emergence using the Fish Water Management Tool

The Fish Water Management Tool (FWMT) is a water management decision support tool designed in part to protect sq̓awsitkʷ|Okanagan River sockeye salmon (<i>sćwin|Oncorhynchus nerka</i>). The FWMT includes a sockeye salmon sub-model to predict emergence timing, a life history stage where sockeye salmon are particularly vulnerable to high (scour) or low (desiccation) flows. Field observations of fry emergence timing were used to evaluate the accuracy of the FWMT sub-model, as well as flow data, spawner data and acoustic trawl data to evaluate the effectiveness of the FWMT. The FWMT predicted the date of peak emergence within an average of 12.6 days and improved compliance with flow targets by reducing desiccation and scour flows during incubation and fry migration life stages. Overall, the FWMT provides a flexible framework that allows water managers to evaluate and react to sq̓awsitkʷ|Okanagan River sockeye salmon responses to environmental conditions, rather than being constrained to a rigid calendar. These efforts have increased compliance with key flow targets, resulting in improved fry recruitment and a rare success story for fishery recovery.