60 FISH AND GAME COMMISSION. 



gate their species. Then the weakened and dying fish drop down the 

 stream where they are found on the grizzlies at the head of the canal. 

 The same condition exists in Fall River. The reason, in the opinion 

 of the writer, for the nonmigratory habits of the fish in these two 

 streams, is that the temperature varies only slightly in comparison with 

 the Pit River and other streams in this region and the flow is constant. 

 There is but a very small difference between the maximum and mini- 

 mum flow in each of these streams. The water is not affected by the 

 flood conditions as the streams are short, receiving their supply from 

 the large springs which have a constant head throughout the year. 

 The aquatic insects and crustaceans on which the fish feed are 

 abundant, the water is nearly all clear, seldom, if ever, getting riley. 

 All these and many other physical conditions relating to the stream 

 beds, velocity of the water, etc., all have a tendency to cause these 

 fish to acquire habits that make them nonmigratory. The writer has 

 studied the conditions in these streams and the habits of these fish 

 for many years and is satisfied that his judgment is correct. But to 

 make an absolute test to either prove or disprove that the writer has 

 not made an error regarding the habits of the trout in these two 

 streams a rack-screen will be installed below Power House No. 1 of 

 the Pacific Gas and Electric Company. For this experiment, the 

 Commission is working in conjunction with the power company. The 

 cooperation of the Bureau of Fisheries has also been obtained and the 

 foreman of the Baird Hatchery has been instructed to assist in the 

 investigation. Members of the sportsmen's associations will be 

 requested to assist in checking up on this experiment to determine 

 beyond any question of a doubt whether there is any loss caused by the 

 trout passing through power wheels, and if so, to what extent. 



This experiment will be carefully checked by the biologist of this 

 department, Mr. Geo. A. Coleman, so that if any fish are found on the 

 rack-screen, the cause of death can be determined. If only emaciated 

 and dying spawners show up, which can be easily determined by 

 dissection and study of the anatomy of the fishes, it will be unnecessary 

 to screen the canals leading to the power houses that receive their 

 water from Hat Creek and Fall River. But on the other hand if 

 healthy fish in normal condition are found on the racks, it will be 

 necessary to have proper screens installed at the intakes to the canals 

 leading from these two streams. It is planned to keep the rack -screen 

 in place for a period of approximately one year so that every condi- 

 tion of seasonal change that might possibly cause the fish to descend 

 into the canals can be observed and data gathered. 



Spiny Bayed Fishes. Owing to the great demand on our trout 

 streams, we deem it advisable to establish pond rearing systems for the 

 propagation of such food and game fishes that will thrive in the warmer 

 waters of. the state. Properly constructed ponds and nurseries for 

 this purpose will be built and the rearing of these fishes placed in the 

 hands of experienced pond culturists. Several millions of the spiny- 

 rayed fishes can be raised each season and distributed in suitable waters 

 the same as trout are distributed. This would add greatly to the 

 fishing attractions of the state and relieve the rush of anglers to our 

 trout lakes and streams. 



Holding Ponds and Rest Stations. Owing to the demand of a 

 number of sportsmen's associations, for the raising of trout to a larger 



