ABSTRACT
Trout habitat modeling attempts have led to the development of the Ontario Trout Habitat Classification (OTHC). This model has been developed using discriminant function analyses to relate trout habitat variables to braod categories of trout biomass density following the work of J. N. Bowlby and J. C. Roff. Nevertheless, these efforts have led to a greater understanding of the relationships between trout populations and habitat in streams. Moreover, these efforts have steered researchers in a direction which may lead to solution of some of the past inadequacies of models that predict fish populations from stream habitat. Different life stages of fish have different habitat requirements. This chapter examines two models used to predict trout biomass density habitat (Habitat Quality Index (HQI) and OTHC), their problems, and proposed solutions. The review of HQI and OTHC has pointed out some of the problems involved in modeling trout habitat quality in streams.
