FISHERIES IN MICHIGAN WATERS OF GREEN BAY 



the 9 years 1900-1908. The downward trend was 

 even more pronounced in the percentage contribu- 

 tion of walleyes to the annual totals. This per- 

 centage was 4 or greater in every year before 1898 

 and was as high as 9.6 (in 1892) . During the last 

 11 years of the period, walleyes made up more than 

 3 percent of the annual yield only twice and 

 accounted for less than 2 percent in 4 years. 



The production of sturgeon, a species once abun- 

 dant in the Green Bay area (cf. Milner 1874, Smith 

 and Snell 1891), already had fallen to a low level 

 by 1891. The decline continued irregularly dur- 

 ing the 1891-1908 period. 



Too much should not be made of a comparison of 

 production in 1891-1908 with that in 1885 since we 

 cannot be certain that conditions in the single 

 earlier year were representative of the middle 

 1880's. It does appear, however, that the species 

 composition of the catch changed markedly from 

 1885 to the early 1890's even though the actual 

 total yield did not rise to a point consistently above 

 the 1885 level until 1895. It is true that the lake 

 herring was the principal fish taken in 1885 as it 

 was in 1891-1908; but the percentage contribution 

 to the total was only 39.7 in 1885 as compared with 

 82.4 (range, 71.6 to 90.6) in the later years. 

 Whitefish, on the contrary, fell from 31.0 percent 

 in 1885 to 2.3 percent (range, 1.1 to 6.6) in 1891- 

 1908. The percentage for lake trout also declined 

 markedly from 16.5 to 3.0 (range, 1.2 to 8.2) . 



PRODUCTION IN 1929-49 



Data on the average take and on the percentage 

 contribution of the leading species to the total 



yield have been given in tables 4 and 5 for the 

 years 1929-43 and 1929-49. The former is the 

 "period of reference" established for the descrip- 

 tion of fluctuations in the modern fishery of State 

 of Michigan waters of the Great Lakes. The 

 large discrepancies between certain figures for 

 1929-43 and 1929-49 suggest that in some areas an 

 average or "normal" based on a period even as long 

 as 15 years may have its limitations. In Green 

 Bay the addition of only 6 years' data to those for 

 15 years raised the averages for the production of 

 whitefish, lake herring, and walleyes by 297,000, 

 356,000, and 82,000 pounds, respectively. The 

 corresponding percentage increases of 1929^19 

 over 1929-43 means for these species were : White- 

 fish, 71; lake herring, 50; walleyes, 161. For the 

 remaining four principal species 3 the 1929-49 

 means were lower by 20,000 pounds (lake trout) to 

 108,000 pounds (smelt). The percentage de- 

 creases ranged from 5 for the suckers to 15 for the 

 smelt. The average catch for all species in 1929- 

 49 (3,582,000 pounds) was 544,000 pounds, or 18 

 percent greater than that for 1929-43 (3,038,000 

 pounds). 



Of the two intervals, 1929-43 and 1929-49, the 

 former probably represents the better reference 

 period for the modern fishery since the high levels 

 that have characterized the output of whitefish, 

 lake herring, and walleyes in recent years can 

 hardly be expected to persist indefinitely. 



* For purposes of discussion In this paper, white and red- 

 horse suckers (Catottomut commersoni and Moxostoma spp.) are 

 treated as a single species. Actually, the white sucker predomi- 

 nates strongly in this combined catch. 



200 



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1895 1900 1905 



Figure 2. — All species: Commercial production in State of Michigan waters of Green Bay, 1891-1908, in millions of 



pounds and as percentages of the 18-year mean. 



