Some observations on autumn‐spawning charr, Salvelinus alpinus L., in Windermere, 1939–1982

Every year from 1939 to 1982 autumn‐spawning charr, Salvelinus alpinus L., have been monitored in the north basin of Lake Windermere. Gillnets of mesh 32 mm bar were used. Up to 1974 the nets were set in Low Wray Bay, but, because of interference by the public, from 1975 they have been set at Thompson Holme, a less accessible site. The results from the two sites are not directly comparable. The main spawning time is November, and catch per unit effort (net day) in November has been calculated. From 1944 to 1974 the catch per unit effort showed an increasing trend, and from 1975 to 1982 it has been relatively stable. Growth was similar in the 1940s and 1970s. It is suggested that the increase in numbers of charr could be due to reduced predation by pike.