TWENTY-SEVENTH BIENNIAL REPORT. 35 



who are not fish eiilturists or seieiitists. su<i<;-est as feasible Unvj; fishways 

 on easy gradients with rest pools at convenient phices for the [jassage of 

 salmon over and around the higli chuns that are being proposed by pro- 

 moters of hydro-electric power enterprises. The instinct of the salmon 

 to follow the main stream is sure to make any of these plans a failure. 



Tlie salmon run in the Klamath Kiver should be maintained J"or the 

 use of the people as a food supply as well as to furnish eggs to keei) up 

 the supply in the Sacramento and Eel Rivers. Hydro-electric projects 

 and irrigation canals have cut off eighty per cent of the spawning 

 grounds on the tributaries of the Sacranu'uto and San Joaquin rivers. 

 The Bureau of Fisheries is assisting in every way possible to maintain 

 the salmon supply by operating their hatcheries and egg collecting sta- 

 tions at Battle Creek, Mill Creek and Baird in Northern California. 

 Their work must be augmented by the surplus eggs from the Klamathon 

 station on the Klamath river, if we are to have the salmon run main- 

 tained in numbers sufficient to be of any great benefit to the people. 



Referring again to the situation on the Klamatli River ; if the fishways 

 should be constructed that would allow the salmon to ascend above the 

 dams to their natural breeding grounds and to the egg collecting sta- 

 tions, the fry, the result of natural propagation or from the hatcheries, 

 would be destroyed in passing through the wheels used to operate the 

 generating plants as it is impossible to construct a screen of sufficient 

 fineness to prevent the fry of anadromous or sea running species of 

 fishes from entering the pipes or tubes that furnish the water to the 

 -power plants. A great deal has been said and written by the promoters 

 of the projects regarding the installation of electric fish stops, by the 

 use of electrodes to develop an electrical current in the water near the 

 end of the intake pipe. Experiments have satisfied us that the plan is 

 not practical. Freshwater fishes or those that spend their entire lives 

 in fresh water, do not descend the streams in schools or Avith such a 

 strong instinct to descend with the current as do the anadromous fishes. 

 The anadromous fishes such as the different species of salmon and the 

 steelhead trout are impelled by their instincts to descend the rivers to 

 the ocean, no matter what obstacles may be placed in their way. They 

 must enter the ocean to develop to maturity, and no electrical current 

 passing through the water that causes a tingling or stinging sensation is 

 going to stop them. If the electrical current is made too strong or strong 

 enough to stop their power to swim, they are either killed or stift'ened up 

 so that their powers of swimming are paralyzed and they Avill drift with 

 the current into the pipes leading to the impulse wheels. Screens with 

 meshes small enough to stop the descent of the fry would choke up dur- 

 ing the flood season when the fry are making their descent to the sea and 

 at other times, and would be removed by operators of these power 

 plants, so the flow of water to their generators Avould not be interfered 

 with. Screens in ditches and canals can be easily installed and cleaned, 

 but screens fine enough to prevent the fry of anadromous fishes from 

 entering pipes leading from high dams to power wheels are not practical. 

 Freshwater fishes whose habits are to live their entire lives in the streams 

 and lakes and rivers are easily turned away by ordinary screens as they 

 are not impelled by a strong instinct to descend the streams. They 

 move from different places in the stream in search of food and breeding 



