The population dynamics of brown trout (salmo trutta L.) in relation to year-class size

Studies on the production of brown trout and yeald of smolt were carried out in a small Dansih sea-trout stream since 1978. Two sites were studied and the production ranged from 16.9 to 26.4 wet wt. or 20.6to 32.1 kcal m^-2 yr^-1. In April and May the smolts lave the brook when they are 2 years old and the yield varied from 14.6 to 19.8 smolt 100 m^-2. the whole brook was electro-fished each year in November and using a growth model and estimated rates of mortality, the production in the total brook was found ranging from 12.0 to 16.6 g. wet wt. or 15.2 to 20.0 kcal m^-2 yr^-1; this indicates a food consumption from 96.2 to 114.2 kcal m^-2 yr^-1