Trout Populations and Habitats in New South Wales

Abstract

Surveys of most of the trout waters in New South Wales have been made. Relevant data of the trout areas are given in respect to geography, generalized topography, and climate. Chemical and physical conditions of the waters are tabulated. Growth rates of trout and quantitative data on the bottom fauna of some streams have been determined. It is shown that the biological, chemical, and physical characteristics of the trout habitats are related and interdependent to a marked and consistent degree. The waters are separated into three groups on the basis of trout growth. The data suggest that the majority of waters in New South Wales often provide conditions which are limiting for trout.

Preliminary population and mortality studies have been made on small sections of nine rivers and on one small lake. The results of a creel census are given. The information from these sources confirms conclusions obtained from the habitat surveys. In addition evidence is presented indicating that certain management procedures should be modified. These include legal length, closed season, and stocking of streams. It is suggested that some of these modifications would have the additional benefit of reducing predation, and that hatchery-reared trout could be utilized on a much wider basis than at the moment for cold-water fish farming.