10 



FISHERY BULLETIN OF THE FISH AND WILDLIFE SERVICE 



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1930 



1935 



1940 



1945 



Figure 9. — Lake trout: Production (solid line), abundance (long dashes), and intensity of the fishery (short dashes) 

 in State of Michigan waters of Green Bay, 1929-49, as percentages of the 1929-43 mean. Production is also given in 

 pounds on scale at the left. 



Lake herring: From a level of 396,000 pounds 

 in 1929 the yield rose to 521,000 pounds in 1931, 

 dropped to the 21-year minimum of 160,000 pounds 

 in 1933, and then increased to 1,834,000 pounds in 

 1937 (fig. 11). A second decline, to a low of 

 285,000 pounds in 1942, was followed by yet an- 

 other upward trend (interrupted by a decrease in 

 1947) which culminated in an output of 2,668,000 

 pounds, the 21-year maximum, in 1948. The 1949 

 yield was 2,230,000 pounds. 



Walleye: The take rose from 27,000 pounds in 

 1929 and 1930 to 108,000 pounds in 1933 and 1934, 

 and then declined irregularly to the minimum of 

 16,000 pounds in 1942 (fig. 12). Production con- 

 tinued to be relatively low during the next 3 years, 

 but 1946 saw the start of an upswing that led to 

 a record yield of 1,063,000 pounds in 1949. 



Yellow perch: Production statistics for perch 

 exhibit little indication of the cyclic fluctuations 

 that characterized the lake trout, whitefish, lake 

 herring, and to some extent, the walleye (fig. 13). 

 Except for the high production of 1937-39 (catch 

 more than 250,000 pounds in all 3 years and 361,000 

 pounds in 1938) and a tendency toward small 

 yields in recent years (output below 100,000 pounds 

 in 4 of the last 6 years and only 49,000 pounds in 

 1944) the fluctuations in the take of yellow perch 

 can be described as erratic. 



White and redhorse suckers : The catch of suck- 

 ers, much like that of perch, varied erratically. 

 (See fig. 14.) The principal features aside from 

 this irregular fluctuation were the rise from the 

 low catch of 393,000 pounds in 1929 to 714,000 

 pounds (near the mean level for 1929-43 and 1929- 

 49) in 1931 and the high output in 1935-37 when 

 the take was approximately a million pounds in 

 three consecutive years. 



Smelt: This introduced species (see Van Oosten 

 1937, for an account of its introduction and spread 

 in the Great Lakes) first entered the commercial 

 fishery in 1931 (less than 500 pounds caught). 

 The take did not exceed 100,000 pounds until 1936 

 or 500,000 pounds until 1938 but large increases 

 in 1940 and 1941 carried the output to nearly 3 

 million pounds in the latter year. From this 1941 

 peak the catch dropped to less than 500 pounds in 

 1944. The declines in 1943 and 1944 were the 

 result of the 1943 epidemic that all but extermi- 

 nated the stock (Van Oosten 1947). Production 

 recovered slowly in the ensuing years and exceeded 

 a million pounds in 1949. 



Total production : The combined catch of all 

 species (fig. 15) rose from 2,319,000 pounds in 1929 

 to 2,924,000 pounds in 1931, declined to 1,418,000 

 pounds in 1933 and then increased five consecutive 

 years to 4,004,000 pounds in 1938. A drop to 



