Production and Movement of Juvenile Rainbow Trout (Salmo gairdneri) in a Headwater of Bothwell's Creek, Georgian Bay, Canada

Abstract

Within the 21,500 m2 headwater, the standing population of juvenile rainbow trout reached a high of 7.05 g/m2 in October. Production was maximum during August at 1.77 g/m2. Total annual production is calculated at 284.5 kg (13.2 g/m2). Spring emigrants (no less than 4830 fish weighing 69 kg) were age I (91%) and age II. Minimum calculated ratio of production to yield as emigrants was 4.1:1. Comparatively few age 0 fish emigrated during summer. Because of their demonstrated capability to produce juveniles, sensitive headwaters must be preserved from ecological disturbance to assure self-perpetuating rainbow trout populations in the Great Lakes.