ABSTRACT
The relationship between aquatic fish habitat and river flows frequently relies on habitat preference criteria (HSC). HSC are based on multiplicative preference curves for depth, velocity and other variables, such as substrate. The assessments of weighted usable area WUA and instream flow needs IFN for fish depend on the quality of the applied HSC. So accurate application of HSC is important to quantify the quality and extent of aquatic habitat. In this study, the assessment of transferring HSC within different Canadian rivers on estimating WUA and IFN was tested. WUA for different fish species were estimated using sets of HSC either developed from fisheries and habitat surveys at each study site or borrowed from different study sites in the same river or another river. It was found that for the same species, different values of IFN were estimated in the different reaches of the same river or different rivers. So transferring HSC between reaches of the same river or between rivers is not recommended and may lead to different IFN recommendations.
