362 
River, fishing with the trammel net floated 
is limited mainly to the upper ends of the 
pools where there is enough current to 
drift the net. 
The float method of fishing with the 
trammel net is limited not only in use but 
in the kinds of fishes it takes. The shovel- 
nose sturgeon, or hackleback, is the prin- 
cipal species taken by the float method. It 
may be noted in table 26 and fig. 17 that 
this species of sturgeon was not taken in 
the survey collections made with set tram- 
mel nets. The trammel net float was the 
only method by which the survey crew 
was able to take shovelnose sturgeons in 
numbers. ‘The only shovelnose sturgeon 
taken by the survey party with other gear 
or methods of fishing was a single speci- 
PER CENT OF TOTAL NUMBER 
BUFFALOFISHES 
FRESHWATER 
SHOVELNOSE 
STURGEON 
DRUM 
CARP 
ItLinois NaturAL History SURVEY BULLETIN 
Vol. 26, Art. 4 
men in a hoop net at the New Boston sta- 
tion. However, in the MR-C section of 
the river, sturgeons are taken on trot lines 
by commercial fishermen. 
Trammel net floating is an important 
method available to commercial fishermen 
interested in fishing for shovelnose stur- 
geons. This method of fishing makes it 
possible to harvest a fish crop that might 
otherwise be lost to man. The freshwater 
drum was the only other species taken by 
the float method in large enough numbers 
to be of importance to commercial fisher- 
men. 
Sport fishes are seldom taken in the 
Mississippi River by the float method. In 
108 floats, only 5 sport fishes were taken, 
of which all were saugers, table 26. 
Ee] TRAMMEL NET SETS 
MMB TRAMMEL NET FLOATS 
I 
| on | 
4 Ww 
5 SRS 
ro) 7) 2) 
ti a te Eon Win 
a a Iv =e o 
wey a ui oe ow a 
rec a xIo wt as 
EOL a ea [rad of 
ook ° On ok Li 
Fig. 17.—The relative numbers of commercial, sport, predator, and forage species of fish 
taken in trammel net sets and in trammel net floats on the Mississippi River between Grafton, 
Illinois, and Dubuque, Iowa, in 1944 and 1946. 
The graph is based on the total number of fish 
taken by each of the two methods of fishing, table 26. 
