306 



FISHERY BULLETIN OF THE FISH AND WILDLIFE SERVICE 



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Figure 3. — Commercial production of whitefish in Lake Michigan, 1890-1939. Short dashes, State of Wisconsin waters; long dashes, State of 



Michigan waters; solid line, entire lake. 



The general level of the yield was lower over the period, 1911-1926, than in 1889 

 and 1891-1908; the 1911-1926 average was only 1,361,000 pounds. The catch was 

 between 1 and IV2 million pounds in 10 of the 16 years. Four years (1916, 1917, 

 1918, and 1926) had productions of more than 1% million pounds (more than 2 mil- 

 lion pounds in 1917 and 1918) and two years (1920 and 1921) had yields of less than 

 a million pounds. 



An increase in production that got under way as early as 1924 and proceeded 

 slowly in the years, 1924-1926, became sufficiently rapid in 1927 to raise the catch 

 above 2 million pounds. The catch continued to increase rapidly until a maximum 

 of 4,813,000 pounds was reached in 1930. The subsequent decline did not carry 

 the take of whitefish below 2 million pounds until 1934. The average yield for the 

 7 years, 1927-1933, was 3,386,000 pounds. This average was greater than the largest 

 yield reported for any single year earlier than 1929 with the exception of 1889 and 

 possibly of some other years prior to 1891 — years for which accurate statistics are 

 lacking. 



The average production of whitefish in the most recent period, 1934-1939, was 

 1,191,000 pounds. The yield exceeded 1^ million pounds in only one year (1934), 

 and in two years (1936 and 1939) it was not far above the lowest catch recorded for 

 any previous year (806,000 pounds in 1920). 



The history of the production of whitefish in the State of Michigan waters of 

 Lake Michigan may be summarized as follows. The catch fluctuated about a level of 

 somewhat more than 2% million pounds during the earliest period (1889 and 1891- 

 1908) for which reliable statistics are- available; the annual yields tended to be below 

 average and to decrease in the earlier years and to be above average and to increase 

 in the later years of this period. The level of production was relatively low in the 

 years, 1911-1926, with the catch exceeding V/o million pounds in only 4 of the 16 

 years. The grand average of 1,909,000 pounds covering both periods (1889-1926) may 

 perhaps be accepted as the normal yield in these Michigan waters. The years, 1927- 

 1939, constituted a period of wide fluctuations in production that resembled the varia- 

 tions that took place in the State of Michigan waters of Lake Huron at about the 



