The Relation of Lake Population Density to Size of Young Sockeye Salmon (<i>Oncorhynchus nerka</i>)

Abstract

For Cultus lake, B.C., data concerning relative numbers of young sockeye inhabiting the lake each year were obtained from the count of seaward migrants. From samples of the latter the sizes of the migrants were determined. For all years, 1927–1937, a statistically significant inverse correlation of −0.815 existed between extent of lake population and size of migrants. Under natural conditions the lake's sockeye productivity seems limited, probably due to limited plankton crop, and the sockeye values obtained in each year are compared to a production level of 6,000–8,000 kg. Experiments in reducing predaceous fish populations indicate appreciable increase in sockeye production.