REPORT UPON THE PISHES OF IOWA. 
219 
Tlie streams of southwestern Iowa have usually very muddy bottoms, while those 
elsewhere, having stronger currents, are generally characterized by sandy, gravelly, 
or rocky bottoms. The former are the least adapted to fish life and are not rich in 
either species or individuals; with the latter the contrary is the rule. 
There are within the limits of the State a few lakes of moderate size; these are 
situated on or near some watershed and each is fed by only a few small streams. The 
most important are Clear, Storm, Spirit, and Okobojis Lakes. Clear Lake is very 
shallow ; Storm and Spirit Lakes are successively somewhat deeper, while Okobojis 
is by far the deepest of them all. 
All of the more important rivers have one or more, sometimes many, dams across 
them ; and few, if any, of these are supplied with fish ways. As a rule, the dams are 
not firmly constructed, and every spring many are washed away, never to be rebuilt. 
During the spring of 1890 much injury was done to the dams in the northeastern part 
of the State, where these structures are more common than elsewhere, but in 1891 the 
region about Cherokee suffered most in this respect. At many places where dams 
exist the streams widen out above them, forming shallow lakes. These areas contain 
much swamp vegetation, and seem to have become fairly stocked with bass, pickerel, 
and sunfishes. The same fishes, I am told, have increased in abundance in such 
localities since the dams were built. 
All of the streams examined by the writer, except perhaps a few in the southwestern 
part of the State, were well supplied with the smaller fishes. With respect, however, 
to the abundance of the larger forms, it was often difficult to reach satisfactory con- 
clusions by the use of the ordinary collecting seines. In the bayous along the larger 
streams young black bass, pickerel, and various species of sunfishes were always 
found in large numbers. Mi. B. F. Shaw, at one time fish commissioner of Iowa, did 
very effective work during his occupancy of that office in seining the fishes out of many 
of these bayous, where a great mortality occurs annually, and depositing them in 
the lakes and rivers. He was the first to suggest and put into practice this efficient 
method of transplanting and preserving the native species, but the work was not con- 
tinued subsequently, as it should have been. Much would be gained by again resort- 
ing to this economical system of propagation, the utility of which has been sufficiently 
demonstrated in Illinois and other adjacent States. There is at present, however, a 
growing interest among certain Iowa sportsmen to organize for the purpose of pre- 
venting the illegal taking of game of all kinds and of assisting in the protection and 
increase of our native food-fishes. 
As a result of observations, it was found that the temperature of the coldest 
springs in the State was about 48° F. ; but in few streams was the water temperature 
below 60° F. In nearly all such cases the range was from 70° to 75° F., but it should 
be taken into consideration that these observations were chiefly confined to the 
warmer months. 
