336 



FISHERY BULLETIN OF THE FISH AND WILDLIFE SERVICE 



The deep trap net became the dominant gear for the taking of whitefish in only 

 three (M-2, M-3, and M-7) of the eight districts of Lake Michigan (table 14 and 

 appendix B), and maintained that position in the first two districts only 2 years (1932 

 and 1933) and in M-7 only 1 year (1934). With the exception of the fishery in M-7 in 

 1934, deep trap nets were operated only sporadically in waters south of M-3. 



Although the actual yield of whitefish in each district and the percentage distribu- 

 tion among the several districts of the total for the lake both varied rather widely in 

 Lake Michigan during the period, 1929-1939 (table 15) , there is no evidence of a shifting 

 of the center of production comparable to that which took place in Lake Huron. For 

 example, M-3 did not relinquish once its position as the most productive district of the 

 lake; neither did northern Lake Michigan (M-l, M-2, M-3, and M-4) fail in any year 

 to account for more than 50 percent of the catch of the entire lake. 



Table 15. — Total annual ■production of whitefish in pounds in the different districts and areas of the State 

 of Michigan waters of Lake Michigan, 1929-1939 



[Eich total is expressed also as the percentage (in parentheses) of the production of the entire lake] 



Nevertheless, the relative importance of the districts varied considerably. M-3 

 produced as little as 36.1 percent (1931) and as much as 52.4 percent (1935) of the 

 total catch of whitefish in the lake. In M-l, the district that ranked second in average 

 yield, the percentages ranged from 10.3 (1936) to 31.7 (1938). The district that 

 ranked third in average production (M-5) yielded from 5.8 percent (1930) to 28.3 per- 

 cent (1937) of the total for the lake. 



The percentage contributions of the less important districts varied relatively more 

 widely than did those for the more productive areas. The greatest relative variation oc- 

 curred in M-7 which produced 9.9 percent of the 1934 total but only 0.1 percent of the 

 1938 catch. However, among the five districts that each accounted for less than 10 

 percent of the 1929-1939 average only one (M-8) produced more than 10 percent of 



