FORTY-SECOND BIENNIAL REPORT 161 



7. The movement of steelhead and salmon in streams is often obstructed by barriers 

 resulting from logging, mining, and road building, and it is only proper that 

 the owners or operators be required to prevent or remove such obstructions. 



S. Proper conditions for fish production can also be destroyed by the filling of 

 lakes and streams with the products of erosion, and every assistance will be 

 given to agencies directly concerned with the control of erosion and pollution. 



9. Constant vigilance will be maintained to prevent the introduction, either offi- 

 cially or unofficially, of plants, fishes, or other animals which might prove 

 harmful to existing fishes, either directly or indirectly. At the same time, con- 

 tinuing studies will be made to discover new introductions which could be made 

 safely to improve the productivity of certain waters. 



California was naturally endowed with an excellent supply of trout and salmon 

 in the cooler waters. Fishes suitable for warmer reservoirs, lakes and streams 

 were few in number. A wide variety has been introduced by the Fish and Game 

 Commission over the years. On the whole, these introductions were useful, but 

 some mistakes were made. Introduction of other game and forage fishes may be 

 desirable in the future but new fishes will not be brought in unless all available 

 evidence indicates that the benefits will be substantial and the hazards few. 

 Initial introductions would be made where spread to other waters in the State 

 can be controlled. 



B. TROUT POLICY 



1. Siuce the majority of trout caught are the result of natural propagation, every- 

 thing possible will be done to aid and protect natural production. Assistance will 

 in large part consist of the protection and improvement of habitat, but will also 

 include protection from disease and predators. Research will be carried out as 

 needed to solve management problems. 



2. Artificial propagation is a useful and important part of trout management and 

 will be used where necessary and helpful. It is not, however, a universal answer 

 to all fishery problems and will be subject to constant checks to determine the 

 results obtained. 



3. Present evidence indicates that in heavily fished waters the planting of trout 

 of catchable size increases the angler's take and resultant satisfaction, but is 

 expensive. This type of planting will be developed only as rapidly as funds are 

 available from those enjoying that type of trout angling. 



4. Fingerling trout plants have but slight value in most streams already contain- 

 ing trout. The major use of fingerlings will be in naturally barren waters, in 

 those waters where the population has been destroyed, and in the small and 

 lightly fished lakes. 



5. The planting of catchable trout is most effective in easily accessible roadside 

 waters, especially lakes, and they will therefore be given first priority. Due to 

 the cost of catchable trout, they shall not be planted unless a large number, 

 usually over 50 percent, will be taken by anglers. Waters only seasonably suit- 

 able for trout shall not be planted except in those areas of the State where the 

 potential fishing pressure is extremely high because of a lack of more suitable 

 waters. Even there they should not be planted unless the fishing pressure is 

 heavy enough to remove at least 50 percent while water conditions are favorable 

 for trout. 



(5. In the setting of open seasons for trout and salmon special protection will be 

 be given to spawning fish and the young of steelhead and salmon before migra- 

 tion to the ocean. 



C. WARM-WATER FISHES 



1. The great variation in the productiveness of our warmer waters indicates that 

 additional knowledge as to the controlling factors is more likely to increase the 

 production than is random planting. Management founded on basic facts will 

 therefore be the method of attack. 



2. Native warm-water game fishes were few in California waters, and of those 

 introduced years ago, black bass, sunfish, and catfish have prospered in certain 

 waters. They supply part of the angling for about 30 percent of California 

 anglers. Where conditions were suitable production has been satisfactory with 



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