78 



FISHERY BULLETIN OF THE FISH AND WILDLIFE SERVICE 



1941; Van Oosten, Hile, and Jobes 1946). The 

 boundaries of the eight statistical districts, M-1 to 

 M-8, are given in figure 2. 



PRODUCTION TRENDS IN LAKE 

 MICHIGAN, 1879-1949 



The trends of production of lake trout from 1879 

 through 1949 perhaps can be brought out best 

 through comments on the yield over certain 

 periods of years (tables 1 and 2; fig. 1). 



The take in 1879, the fu'st year for which we have 

 a record, was comparatively low (2,659,000 

 pounds). Catches were higher in 1885 (6.431,000 

 pounds) and 1889 (5,580,000 pounds) but the take 

 in each of those years and the mean for the two 

 (6,006,000 pounds) were far below the level that 

 characterized the period beginning with 1890. 

 It may be assumed that the fishery was in the 

 process of development in 1879-89. 



The interval 1890-1911 was one of rather con- 

 sistently high production. The take exceeded 8 

 million poimds in 7 of the 11 years for which lake 

 totals are recorded and was more than 9 million 

 pounds in 1 of these 7 (9,282,000 pounds in 1896). 

 Of the remaining 4 years, 2 had yields between 7 

 and 8 million pounds, 1 between 6 and 7 million, 

 and 1 less than 6 million. The two lowest catches 

 (6,624,000 poimds in 1892 and 5,286,000 pounds 

 in 1899) both deviated sharply from the general 

 level for the period and both can be attributed to 

 the low yields recorded for Wisconsin. The grand 

 average catch => for 1890-1911 was 8,230,000 

 pounds or 2,224,000 pounds greater than for 1885- 

 89. Every State but Indiana shared in the in- 

 crease; the rise was greatest, however, in Wiscon- 

 sin (1,950,000 pounds). 



The production of lake trout in Lake Michigan 

 was at a decidedly lower level in 1912-26 when the 

 average yield of 7,007,000 pounds was 1,223,000 

 pounds below that of 1890-1911. Of the 14 years 

 for which there are totals (see footnote 1 to table 1 

 concerning the exclusion of data for Wisconsin in 

 1921) 5 had catches between 7 and 8 million 

 pounds, 8 between 6 and 7 million pounds, and 1 

 less than 6 million pounds. The highest yield was 

 7,928,000 pounds in 1915 and the lowest was 

 5,979,000 pounds in 1918. Dechnes from the 

 preceding period of 932,000 pounds in Wisconsin 



> To obtain full use of the data of table 1, the means in the body of table 2 

 were determined from all records of yield for each State during the indicated 

 periods and these State means were added to obtain the totals at the right. 



and 459,000 pounds in Michigan, were compen- 

 sated to a small degree by increases of 132,000 

 pounds in Indiana and 36,000 poimds in Illinois. 



Table 1. — Production of lake trout in Lake Michigan, 

 1879-1949 



[In thousands of pounds] 



1 The recorded yield of 8,642,000 pounds in Wisconsm in 1921 is so badly 

 out of line with data for neighboring years as to be held unreliable. It was 

 not plotted in fig. 1 or employed in the computation of any means or per- 

 centages. 



2 No breakdown available of the 371,000 pounds taken in Indiana and Illi- 

 nois. 



» Less than 500 pounds. 



