Northern Pike Year-Class Strength and Spring Water Levels

Abstract

Relationships between spring water levels and strength of year classes of northern pike (Esox lucius) produced in Ball Club Lake of north-central Minnesota are considered for the 7 years between 1945 and 1952. The years are ranked according to water conditions, including height during spawning and fluctuation during egg incubation, and according to the strength of year classes produced as judged from their abundance in the darkhouse spearing catch. Comparison of these two rankings by a rank difference correlation shows a correlation of 0.61. It is concluded that a high spring water level during spawning and a small decline in the levels during egg incubation represent good conditions for the production of a strong northern pike year class.