380 FISHERY BULLETIN OF THE FISH AND WILDLIFE SERVICE 



of treated nets averaged a little less than a half inch smaller than the mesh size as manu- 

 factured. The amount of shrinkage varied widely, however, in the individual nets. 

 Because of this variation the minimum legal size of mesh should be specified "as found 

 in use" rather than "as manufactured." Once a net has been treated, it is impossible 

 to determine exactly the original size of the mesh. 



APPENDIX A 

 SOURCES OF THE DATA ON PRODUCTION, 1879-1939 



The following paragraphs contain the details concerning the sources of the produc- 

 tion data of table 1. Where more than one source was available for any single year, 

 preference usually was given to that with the most continuous record over a period of 

 years. 



(1) Sessional Papers of the Parliament, Dominion of Canada: all data for the 

 Canadian waters of Lake Huron, 1879-1905. 



(2) Annual Reports of the Game and Fisheries Department of the Province of 

 Ontario: all data for the Canadian waters of Lake Huron, 190&-1939. 



(3) Reports of the United States Commissioner of Fisheries and his administrative 

 successors: all data for United States waters, 1879 (repeatedly listed erroneously in the 

 reports as for 1880) and 1885; United States waters, except the Wisconsin waters of 

 Lake Michigan, 1890 (including the total for the Lake) ; Wisconsin waters of Lake 

 Michigan, 1926-1939; total for Lake Michigan, 1925; Indiana and Illinois waters of 

 Lake Michigan, 1879, 1885, 1890, 1897, 1903, 1917, 1922, and 1925-1939 (actually, no 

 whitefish catch was reported from these States in 1938 and 1939). The Indiana and Illi- 

 nois catches of whitefish in Lake Michigan for the above years, although not recorded in 

 table 1, have been included in the Lake Michigan totals. All other Lake Michigan 

 totals for individual years, except 1889 and 1908, are exclusive of the Indiana and 

 Illinois catches. 



(4) Reports of the State of Michigan Department of Conservation and its ad- 

 ministrative predecessors: State of Michigan waters of Lake Michigan, 1911; State of 

 Michigan waters of Lakes Huron and Michigan, 1912-1928. 



(5) United States Bureau of the Census — Fisheries of the Great Lakes, Census 

 Bulletin no. 173: all United States waters (including catches in Illinois and Indiana), 

 1889. Fisheries of the United States, Special Report: Wisconsin waters of Lake Mich- 

 igan. 1908; Indiana and Illinois waters of Lake Michigan, 1908 (not listed in table 1 

 but included in the total for the lake). 



(6) Compilations made from original State records: 



Wisconsin— Wisconsin waters of Lake Michigan, 1890, 1892-1897, 1899, 1903, 

 and 1909-1925. 



Michigan. — Michigan waters of Lakes Huron and Michigan, 1891-1908. 



Michigan. — Compilations from the daily reports of commercial fishermen — State 

 of Michigan waters of Lakes Huron and Michigan, 1929-1939. (These data are 

 treated in detail in part II.) 



Although certain data are available for earlier years, the statistical records for 

 the whitefish fisheries of the United States waters of Lakes Huron and Michigan 

 may be assumed for practical purposes to begin with 1889 and 1891. The 1879, 1885. 

 and 1890 catches included longjaws, blackfins, and Menominee whitefish in Lake 

 Michigan, and Menominee whitefish in Lake Huron. The only clue as to the extent 

 of the errors brought about by these inclusions is provided by the fact that in 1890 

 longjaws, blackfins, and Menominee whitefish made up about 26 percent of the 

 reported catch of whitefish in Lake Michigan (1,398,238 pounds in a total of 5,455,079 

 pounds). The 1890 total for the Wisconsin waters of Lake Michigan is based on State 

 records and is not known to include any species other than whitefish. However, 

 Wisconsin contributes a relatively small part of the total whitefish catch in Lake 

 Michigan. 



As has been mentioned previously, the Lake Michigan totals for several individual 

 vears do not include the catch of whitefish in Indiana and Illinois waters. However, 



