334 



FISHERY BULLETIN OF THE FISH AND WILDLIFE SERVICE 



trap-net fishery in the former lake. With the exception of the deep-trap-net fishery out 

 of Grand Haven, Mich., in 1934 (the deep trap net was the dominant gear for the pro- 

 duction of whitefish in M-7 in that year), significant operations with this gear were 

 confined to the extreme northern portion of the lake (M-l, M-2, and M-3). Deep 

 trap nets were introduced into M-l and M-3 in 1930 and into M-2 in 1931. Even in 

 these northern districts the place of the deep trap net in the fishery resembled that 

 which it occupied in northern Lake Huron rather than in central and southern Lake 

 Huron. At no time did the deep trap net become the dominant gear for the capture of 

 whitefish in the Green Bay area (M-l). In M-2 and M-3 deep trap nets led other 

 gears in the production of whitefish in only two years (1932 and 1933 in both districts). 

 The use of deep trap nets in the Michigan waters of Lake Michigan became illegal 

 after 1935. 28 



The fact that the deep trap net did not disturb the whitefish fishery as seriously in 

 Lake Michigan as in Lake Huron makes it possible to follow a more or less natural 

 course of events subsequent to an abnormal increase in abundance. Comparisons with 

 the data on the whitefish fishery of Lake Huron should prove particularly instructive. 



FLUCTUATIONS IN THE PRODUCTION OF WHITEFISH • 

 IN LAKE MICHIGAN 



The increase in the catch of whitefish that characterized the late 1920's and early 

 1930's in the various waters of the Great Lakes got under way early in Lake Michigan. 29 

 Production exceeded 2 million pounds in 1927 and was nearly 3 million pounds in 1928. 



Table 13. — Production of whitefish in pounds according to gear in the State of Michigan waters 



of Lake Michigan, 1929-1939 



[Percentages of annual yield in parentheses] 



Year 



1929... 

 1930... 



1931 



1932 



1933 



1934... 



1935 



1936 



1937 



1938... . 

 1939.... 

 Average 



Production in gear 



Large-mesh 

 gill net 



2.244,093 

 (52.3) 



2.339,162 

 (48.6) 



1,986,579 

 (51.9) 



1,564,505 

 (46.9) 



1,307,943 

 (58.4) 



1,001,074 

 (51.8) 



911,079 

 (63.6) 



635,284 

 (72.5) 



709,515 

 (74.9) 



765,416 

 (68.5) 



482,801 

 (57.5) 



1,267,950 

 (54.4) 



Deep trap 

 net 



135.634 

 (2.8) 



408,209 

 (10.7) 



856.804 

 (25.7) 



440,090 

 (19.7) 



398.635 

 (20.6) 



211,246 



(14.8) 



222,784 

 (9.6) 



Pound 

 net 



2,032,083 



(47.4) 



2,328,326 

 (48.4) 



1,421,576 



(37.2) 



890,667 

 (26.7) 



485,187 

 (21.7) 



531.070 

 (27.5) 



301,367 

 (21.0) 



240,508 

 (27.4) 



236,527 

 (25.0) 



351,447 

 (31.5) 



r.o.tss 



(42.4) 



834.113 

 (35.8) 



Other 



11.693 

 (0.3) 



9,703 

 (0.2) 



7,619 

 (0.2) 



20,308 

 (0.6) 



2,620 

 (0.1) 



1,399 

 (0.1) 



8,032 

 (0.6) 



619 

 (0.1) 



825 

 (0.1) 



216 

 (0.0) 



567 

 (0.1) 



5,782 

 (0.2) 



Total 



annual 



production 



4,287,869 



4,812.825 



3,823,983 



3,332,284 



2,235,840 



1,932,178 



1,431,724 



876,411 



946.S67 



1,117.079 



839,856 



2,330,629 



Increase 



or 

 decrease 



+ 1,331,723 

 +524,956 

 —988,842 

 —491,699 



—1,096,444 

 —303,662 

 —500,454 

 —555,313 

 +70,456 

 +170,212 

 —277,223 



M Limited operations have been carried on in the northern Michigan waters since 1935, with a modified deep trap net in which the crib or pot 

 extends to the surface of the water and is open at the top. This arrangement has qualified the nets for legal definition as pound nets with which gear 

 they have been grouped in the preparation of this report. 



N In this section the terms, "Lake Michigan" and "the entire lake," refer to the State of Michigan waters only. 



