quantitatively good bottom fauna exists, however, 

 and forms an important link in the fish food 

 chain . 



Navigation pools. There are 26 dams between 

 St. Paul and St. Louis, each of which is capable 

 of shutting off temporarily almost the entire flow 

 of the river. Each of these dams is by -passed 

 by a lock for the use of river traffic . These 

 dams, built in the period 1934-1940, create im- 

 poundments, the purpose of which is to provide 

 depth of water for boat passage. The impound- 

 ments have a profound effect upon such factors 

 as water levels, current, silt deposition, etc., 

 and therefore upon the fish population and the 

 fishing. An investigation of the changed con- 

 ditions brought about by impoundments forms 

 an important part of the work of the Mississippi 

 River Fish Survey. 



This series of dams furnishes a neat 

 artificial system for designating geographical 

 units of the river, since the dams are numbered. 

 This numbering system has been adapted to the 

 creel census operation and will be used in this 

 report . Briefly, the entire area of the river be - 

 tween any 2 successive dams carries the same 

 number as the lower (downstream) of the 2 dams. 

 Thus, "pool 10" designates the stretch of the 

 river, including all backwaters and side channels 

 contained therein, between dam 9 and dam 10. 

 In the 225 miles of river under discussion here, 

 pools 4, 5, 5A, 6, 7, 8, 9, 10, 11, and part of 

 pools 3 and 12 are included. These pools are 

 very unequal in length and consequently in area . 

 For instance, pools 5 and 5A are about 15 miles 

 and 10 miles long respectively, while pool 10 is 

 33 miles long and pool 4 is 43 miles long, in- 

 cluding the 22 miles of Lake Pepin. Orientation 

 can be obtained by reference to a map of this 

 part of the river, remembering that pool numbers 

 go from upstream to downstream . To spot a few 

 principal localities it may be mentioned that Red 

 Wing is in the upper end of pool 4, \Wnona is in 

 pool 6, La Crosse is in pool 8, Prairie du Chien 

 is in pool 10, and Dubuque is at the extreme 

 head end of pool 12 . 



Lake Pepin, although part of the river 

 proper, has many of the properties of an actual 

 lake. It has little current and toward its lower 

 end is up to 30 feet in depth. It has a sigmoid 



shape and is about 22 miles long by 1 to 3 miles 

 wide. Lake Pepin carries the entire flow of the 

 river, there being no side channels paralleling 

 it. 



In order to separate Lake Pepin from the 

 remainder of pool 4, some of which exists as 

 river above and below the lake, it has been as- 

 signed an arbitrary number in the pool -number- 

 ing system. Throughout this report Lake Pepin 

 is designated as "pool 4-L" and the balance of 

 pool 4 is called "pool 4-R". This is unofficial 

 nomenclature not to be found on maps or charts. 



Characteristics of the 

 fishery 



Fishing methods . As would be expected on a 

 fishing water of this size and with various types 

 of topography and a variety of fish to be caught, 

 there is a considerable variation in the kinds of 

 tackle and angling methods employed. Almost 

 all of the common types of tackle are used, in- 

 cluding cane poles, fly rods, bait casting rods, 

 etc. In quantitative terms, however, at least 

 90 percent of the fishing is done by "still -fishing" 

 methods, i.e., with a pole and line in the sum- 

 mer and with a simple line rig in the winter. 

 There is a growing tendency however, toward 

 the use of bait and fly casting equipment. 



In the matter of bait, the preponderant 

 use is of live bait - usually minnows or angle- 

 worms. Artificial baits such as flies, plugs, 

 and spinners, find limited use. Some of the fish- 

 ing, such as that for carp or for catfish, uses 

 various kinds of so-called natural materials 

 such as dough balls, cheese, "stink baits", blood, 

 shrimp, crayfish, cut fish, etc. 



The catch varies both as to quantity and 

 as to kinds of fish with the bait used. For in- 

 stance, most of the blueg^Us are caught on worms, 

 while most of the crappies, bass, and walleyes 

 are caught with minnows. Thus the type of bait 

 used by the mai ority of the fishermen varies 

 from one fishing locality to another in the same 

 pattern that the kinds of fish fished for and taken 

 vary by localities. 



Kinds of fish. The Upper Mississippi River 

 offers an amazing variety of sport fishes . In 



