232 Conservation Department 



mentioned type of bed gave the lowest weight of potential food 

 per unit area of any studied. 



Considering next the potential fish foods available over all types 

 of plant beds, Table 8 shows the relative abundance of each class 

 of food. In a total of 9,084 organisms collected, crayfish and 

 shrimps constituted 42.16 per cent. Most of these were Caledonia 

 shrimps, a few water sowbugs, Asellus, being included. Fly 

 larvae and pupae formed 22.17 per cent and were the second most 

 abundant food in plant beds. Other foods largely eaten by trout 

 occurred in the following ratios: Caddis larvae and pupae, 8.88 

 per cent ; mayfly nymphs, 5.66 per cent and stonefly nymphs, 0.91 

 per cent. Bugs and beetles formed 7.82 per cent and 6.36 per 

 cent, respectively^ ^Miscellaneous organisms, 3.15 per cent, con- 

 sisted of a few leeches, oligochaetes and nematodes and are un- 

 important. 



One fact which this study has definitely shown is that stream 

 or pool bottoms bare of plant beds are much less productive of 

 available fish food than such places in which aquatic vegetation 

 has developed. The average for plant beds (Table 7) is 7.88 grams 

 per one square foot. The average for bare stream and pool bot- 

 toms is 1.05 grams and 0.21 grams (Table 2) respectively, using 

 this year's figures. These findings substantiate last year's results 

 in showing that: (1) plant beds are 37.5+ times as rich in food 

 as bare pool bottoms; (2) 7.5+ times as rich as bare stream bot- 

 toms and (3) stream riffles are 5.0 times as rich as pools in 

 available nutritive elements. 



Effects of Spring Floods upon Aquatic Fish Foods. — On 



March 7, 1927, the writer ran the drift net in Sixmile creek just 

 above the village of Slaterville for approximately fifteen minutes. 

 The w^aters of the creek were a raging torrent due to the sudden 

 melting of a heavy snowfall. This w^as done in an effort to ascer- 

 tain the effects of high w^aters on the bottom organisms which 

 furnish the major part of trout diet. 



The results were most illuminating. Practically every kind of 

 aquatic organism which had been collected from this stream during 

 the previous summer was taken in the net. The great majority 

 were dead or injured by the grinding action of the locks and 

 gravel which were being swept downstream hy the force of the 

 current. Many parts of insect larvae such as heads, legs, tails 

 and abdomens offered simple evidence of the destructive action of 

 high waters. Many aquatics such as the blackfly larvae (Simulium) 

 wiiich are never taken in the drift under normal circumstances 

 and which normally live in fixed j)()sitions on rocks in swift water, 

 were collected, l)ruise(l and l)attere(l as they were carried down- 

 stream. In brief this cari'ies back to the ])r<)l)lem of reforestation 

 which means flood conti-ol and in the end, natui-al and undisturbed 

 ])ropagati()n of n(|ii;ili(' insect lai'vnc upon wliicli. as lias been 

 shown above, trout jh'c dependent for tiie niajoi- |)art of their diet. 



