Biomass, Production, and Yields of Walleye (Stizostedion vitreum vitreum) and Yellow Perch (Perca flavescens) in North American Lakes

Compilation of available data indicated that walleye (Stizostedion vitreum vitreum) biomass in lakes averaged 16 kg/ha, but the data were not adequate to show relationships with mean depth, alkalinity, latitude, or morphoedaphic indexes of the lakes. Yellow perch (Perca flavescens) biomass also failed to show relationships with these factors. In small lakes and ponds with only perch, biomass ranged from 39 to 215 kg/ha, but in lakes with other species, perch biomass was under 65 kg/ha. Annual production of walleye was from 1.2 to 4.1 kg∙ha−1∙yr−1 and that of yellow perch was 21.9 kg∙ha−1∙yr−1. Average commercial yields of walleye ranged up to 3.06 kg∙ha−1∙yr−1, and sport fish yields averaged 3.7 kg∙ha−1∙yr−1. Annual commercial and sport yields decreased with latitude. Area of lake was negatively correlated with sport yield, but positively with commercial yield. The latter situation is believed to be an artifact of the sample and not a general trend. Commercial yield increased with total dissolved solids of the lakes. Lack of other correlations may be related to the fact that walleye biomass and yield do not bear a constant relationship to total biomass and yield. Key words: Percidae, Stizostedion, Perca, biomass, production, yield