common only in the inore isolated backwaters. Emergent aquatic plants 

 were more generally distributed, the common kinds being lotus (Nelumbo 

 pentapetala ) and arrowhead ( Sagittaria latifolia ) . 



Pool 8 supports a commercial fishery vrhich took 8^0,000 pounds of 



fish during the I9I1.8 season. 1/ The important commercial fishes are carp, 

 sheepshead, buffalo and catfish. Parts of this pool are popular fishing 

 grounds for anglers from southwestern Wisconsin and southeastern Minne- 

 sota. Good catches of walleye?, northern pike, panfishes and catfish are 

 frequent. In the area netted, however, angling pressue is so light that 

 the effect of angling take on the fish population and on net catches may 

 be considered negligible. 



GEAR USED 



The trap net was used to sample fish populations at the permanent 

 netting stations in 19lj8 and for other netting surveys conducted north 

 of Dubuque, Iowa. This net is illustrated in Figure 2. It takes most 

 of the species of fish present in the river and appears to be less selec- 

 tive than most other kinds of entrapment gear. It is easily handled by 

 two men and in an emergency can be raised and reset by one man. Since 

 the trap net offers considerable resistance to current it does not 

 operate well in fast waters. 



The fore-part of the net is a box-like frame, six feet wide, three 

 feet high, and two and a half feet deep, to which a 5ri-foot lead is 

 attached. The rear of this frame is fastened to a hoopnet of seven hoops. 

 In the frame is a heart which serves as the first throat of the net and 

 in the hoop-net portion are two throats, the first square and the second 



tapered or "fingered". Mesh of the webbing on the frane is l-l/Ii inch 

 bar measure and on the hoops is 1-inch bar measure. The trap nets used 

 in this study were set at right angles to the bank with the lead extended 

 from the center of the frame to the shore. 



To gain some additional information in fast-water areas, large-mesh 

 commercial buffalo nets were also fished. The buffalo net is a large 

 hoopnet, about 13 feet long, with 7 to 10 hoops that are 3 to I4 feet in 

 diameter. Mesh of the webbing varied from 1-3/U-inch to 2-inch bar 

 measure. Buffalo nets were fished without leads or wings and were 

 anchored in the current to intercept fish moving up stream. Buffalo 

 nets are used by commercial fishermen to take buffalo, sheepshead and 

 carp from the Mississippi below Dubuque, Iowa, but are illegal in 

 Wisconsin-Minnesota boundary waters. 



1/ Sixth Progress Report, Upper Mississippi Riirer Conservation Committee. 

 Technical Committee for Fisheries, 1950 



