Age, Growth, Sexual Maturity, and Population Fluctuations of the Yellow Pike-Perch, Stizostedion Vitreum Vitreum (Mitchill), with Reference to the Commercial Fisheries, Lake of the Woods, Minnesota
- 1 January 1945
- journal article
- Published by Oxford University Press (OUP) in Transactions of the American Fisheries Society
- Vol. 73 (1) , 90-107
- https://doi.org/10.1577/1548-8659(1943)73[90:agsmap]2.0.co;2
Abstract
The scale method of growth analysis is applicable to the pike‐perch of Lake of the Woods, but the body‐scale relationship is that of a third‐degree polynomial rather than a straight line. Length calculations were made using the corrected body‐scale relationship. Female pike‐perch grow more rapidly than the males, but the differences in growth rate are small. Leeˈs phenomenon is pronounced and is apparently due to the selective removal of the faster growing fishes by the commercial fisheries. The growth rate is more rapid during years with high mean summer temperatures, July temperatures being most significant. The weight increases approximately as the standard length raised to the 3.1 power. Male pike‐perch mature when 4 years old, but females usually do not mature until 5 or 6 years of age. Fluctuations in the abundance of pike‐perch are quite pronounced. There is a suggestion of a 10‐year cycle of abundance in the commercial catch. The fluctuations are associated with differences in the strength of various year classes, but the causes of these differences are not evident at present. Fry planting has no apparent effect on the strength of the year classes or the subsequent commercial catch. Depletion of pike‐perch is indicated by the rapid decline in the catch from 1935 to 1939. The depletion is probably due to the destruction of spawning beds by pulp mill wastes and to an excessive drain on the fishery. It is believed that an increase in the size limit would increase the total catch and would provide a more adequate spawning stock. It is also suggested that fishing practices be changed so that saugers and perch may be removed from the lake in proportion to their abundance. At the present time the survival of these two species is favored over the survival of pike‐perch.This publication has 0 references indexed in Scilit: