THE WHITEFISH PRODUCTION OF THE GREAT LAKES. 647 
therefore difficult to find any well-defined area in the American waters of the 
Great Lakes which has been fished under uniform conditions for a period suffi- 
ciently long to permit conclusions to be drawn as to the effect of that fishing. 
Not only have the conditions under which the fishing has been carried on 
varied from time to time in any one locality and at any one time from locality 
to locality, but no complete records are available of the fishing operations in the 
Great Lakes as a whole, or in any single lake, except Lake Huron, for any con- 
tinuous period of years. The United States Fish Commission (now the Bureau 
of Fisheries) has caused statistics to be collected on the fisheries of the Great 
Lakes about once in five years, and these are available for the following years: 
1880, 1885, 1890, 1893, 1899, 1903. The Michigan fish commission has since 
1891 employed a statistical agent, who has annually visited each fisherman and 
personally taken from his books the records of the fish caught and of the nets used. 
The Canadian Department of Marine and Fisheries has for the past thirty-eight 
years published in its annual report detailed statistics of the fisheries in Canadian 
waters. The remaining governments, with the exception of Pennsylvania, are 
able to afford no information about the fishing operations within their borders. 
Not only is investigation hampered by the paucity of statistics, but the 
reliability of the available statistics is often a matter of serious question. The 
difficulties in dealing with whitefish statistics arise from two sources. Even 
when statistics are available for like periods and over the same areas they are 
often widely at variance. The Michigan statistics are taken annually by a 
statistical agent who is in the field almost constantly and who by his long service, 
begun in 1891, has gained the confidence of the fishermen. They are taken 
under a law which requires the fishermen to make sworn returns of their catches. 
Considering all the circumstances, they are probably as accurate as such statistics 
can be made. The data that it has been found possible to use in this paper are 
chiefly those of the Michigan and Canadian fisheries. 
The second source of difficulty referred to has to do with the use of the term 
‘‘whitefish.”” Four fishes of commercial importance are referred to as whitefish. 
These are the common or true whitefish (Coregonus clupeiformis Mitchill), the 
longjaw (Argyrosomus prognathus H. M. Smith), the blackfin, bluefin, or bloater 
(Argyrosomus nigripinnis Gill), and the Menominee whitefish (Coregonus quad- 
rilateralis Richardson). Subsequent to 1891-92 these forms are distinguished 
in the statistical reports of the United States Fish Commission, but previous to 
1893 “whitefish” only are mentioned. The published reports of the Michigan 
Fish Commission, as well as the unpublished records of their statistical agent, 
exclude menominees, blackfins, and longjaws from the rubric ‘ whitefish,” 
which therefore includes only true whitefish. The statistics collected by the 
Department of Marine and Fisheries of the Dominion of Canada, I am assured, 
include true whitefish only and exclude longjaws and blackfins. Our com- 
