944f210d___Changes_in_Fish_Species
[Decade] 1940 [Market Stimulation] food shortages during the Second World War stimulated fish consumption [Fishing Technology] -cotton gill nets were replaced by nylon nets which were up to 3 times more efficient -electronic fish finders and radar became available [Changes in Fish Species] 
Lake Herring catch experienced a peak in 1946 and then crashed, then rapdily declined during the 1950's -Lake Whitefish catch peaked in 1949 then rapidly declined in 1950's -Blue Pike catches fluctuated widely
Changes in Fish Species