138 BULLETIN OF THE BUREAU OF FISHERIES 



Table 1. — Products of the fisheries of the Mississippi River from Minneapolis to Winona in 1903 



and 1922 



[From unpublished files of the Bureau of Flsheriesl 



Species 



1903 



1922 



Food fish, except carp: 



Pounds 

 325 

 405, 245 



Value 

 $26 

 10, 460 



Pounds 



Value 



"Ruffnln fish 



409, 310 

 21, 445 

 147, 016 



$19, 841 

 357 

 13, 208 



Bowfin 



Catfish and bullheads... : 



311, 149 



19,317 

 283, 210 

 6 112 

 202' 260 

 57, 525 

 35, 380 

 14, 305 

 72, 060 

 21, 400 

 14, 585 

 300 

 12, 545 



17, 917 

 827 

 4, 988 

 514 

 6, 142 

 2,702 

 2,028 

 684 

 1,302 

 490 

 642 

 14 

 442 



Crappie 



Drum 



429, 078 

 799 

 16, 271 



13, 529 

 47 

 633 



Eels 



Paddlefish _ 



Pickerel 



Pike perch (wall-eyed) 







Pike perch (sauger). 







Suckers 



57,434 



1, 681 



Sunfish 



Sturgeon 



7,753 



1, 162 





White bass 







Total 







i, 456, 048 

 473, 440 



49, 178 

 8, 969 



1, 089, 106 

 3, 048, 332 



51, 073 

 101, 274 



Carp 



Grand total 



1, 929, 488 



58, 147 



4, 137, 438 



152, 347 





There are few data to aid in estimating the role of the various factors (whether 

 economic or biologic) in causing this decline in the fisheries. No doubt, changing 

 market demand, legislation, overfishing, pollution, and changing physical environ- 

 ment all have affected the fisheries, and it is the object of this report to present new 

 evidence bearing upon this important problem. 



In 1925 a joint interim committee was appointed by the Legislatures of Wis- 

 consin and Minnesota and instructed to obtain data on the general condition of the 

 river and to present these data before the State legislatures in 1927. The interim 

 committee decided that a biological survey should form a part of their general study 

 of the Mississippi River and asked the United States Bureau of Fisheries to furnish 

 an investigator to make this survey. The bureau agreed to do this on the condition 

 that the field expenses of the bureau's investigator should be borne by the State 

 governments. 



Funds to the amount of $20,500 had been appropriated for the Mississippi 

 River work by the conservation commissions of the two States, the Twin Cities, 

 and the United States Public Health Service, of which $300 was made available for 

 the work that the Bureau of Fisheries had been asked to do. This was supple- 

 mented by the bureau to the extent of about $1,000. 



Because of the limited appropriation and time that could be devoted to field 

 work, the results are not as complete as might be desired. Also, as most of the 

 work was done after the heavy rains of last summer had begun, all of the results 

 reported in this paper do not represent conditions as they exist when the river is at 

 its lowest stage and when conditions are most critical. 



AIM AND PLAN OF THE SURVEY 



The aim of the biological survey was to determine whether the pollution from the 

 Twin Cities is a factor in destroying aquatic life in the Upper Mississippi River; 

 and if so, to ascertain, if possible, how far below these cities this pollution constitutes 



