Treating the Russian River to remove unwanted rough fish. 



(Fish and Game Photo) 



A new type of lightweight paddle wheel chemical 

 mixer was developed and was instrumental in the dis- 

 tribution of powdered chemical from boats. The two 

 chief manufacturers of fish toxicants have succeeded 

 in developing highly effective emulsions. These emul- 

 sions are somewhat more expensive than the powdered 

 form, but the savings in equipment and labor used in 

 their application compensates for the additional cost. 



Aircraft Used 



The use of aircraft to spread the chemicals in re- 

 mote mountain lakes was tested and found quite prom- 

 ising. Once developed, this should greatly reduce 

 costs for treatment of certain lakes. 



A total of 58 lakes was chemicall)- treated during 

 the period from July 1, 1954, through June 30, 1956. 

 This treatment will create improved fishing in approx- 

 imately 11,450 surface acres of water. In several in- 

 stances advantage was taken of seasonal drawdowns 

 of reservoirs. Scheduling the treatment when the res- 

 ervoir pool is at a minimum reduces the cost of the 

 job many fold and assures a more successful control. 



An outstanding example of this type of operation 

 took place on the Dallas-Warner Reservoir in Stanis- 

 laus County. This 3,800-acre lake was chemically 

 treated when drawn down to 280 surface acres. 



Air Boat Used 



An air boat (a shallow draft boat powered by an 

 airplane propeller) was used successfully to spread 

 the rotenone over the man\' shallow areas which oth- 

 erw ise would have been difficult to treat. The lake was 

 restocked with suitable varieties of warmwater fish, 

 and thev have produced good fishing. 



San Diego Story 



For the first time in California a municipal water 

 supply impoundment was chemically treated to re- 

 move rough fish. The date was January 31, 1956. The 

 place was Hodges Reservoir of the City of San Diego. 

 Fish toxicant was used to treat this body of water 

 and the fish kill was believed complete. More than 100 

 tons of carp were removed. 



State and local health departments followed the op- 

 eration with considerable interest; no similar project, 

 involving a large supply of domestic water, had ever 

 been attempted heretofore in California. 



The project succeeded in improving both water 

 quality and conditions for a sport fishery. San Diego 

 is one of the few cities that permit fishing in its domes- 

 tic w ater supply; consequently, the success of the fish- 

 killing program is of far reaching importance to 

 anglers all over the State. 



Many Streams Treated 



In addition to the lakes, 25 streams with a total 

 length of approximately 245 miles were treated. Sev- 

 eral streams in the Russian River drainage were 

 treated, completing a job (286 miles) started in the 

 1952-54 Biennium. It was the largest chemical treat- 

 ment program ever undertaken on a river system. The 

 stream was treated to reduce the population of squaw- 

 fish, suckers, roach and carp and improve conditions 

 for natural reproduction of steelhead. 



At the end of the biennium, the rough fish appeared 

 to be making a comeback, but were still not up to 

 their former numbers. 



Aleanwhile summer trout fishing had greatly im- 

 proved. Eff^ects on the winter steelhead fishing will 

 not be felt until the large crops of fish spawned after 

 treatment reach maturity and come back into the 

 riser from the ocean. 



Putah Creek Project 



A second major rough fish control project involv- 

 ing a stream drainage was conducted in Putah Creek, 

 in Napa and Lake Counties. There 45 miles of stream 

 w as treated in an effort to control carp in the drain- 

 age area above the Berr\'essa Reservoir to be created 

 by iMonticello Dam. 



Table 23, Appendix, contains a tabulation of the 

 waters which received complete chemical treatment, 

 and also lists the fish species restocked. 



It does not, however, list the waters which received 

 partial chemical treatment to reduce heavy concentra- 

 tions of undesirable fishes in shallow inlets or shoreline 

 areas. 



Partial controls of this type were undertaken at 

 Cachuma Reservoir, Santa Barbara County, and at El 

 Capitan Reservoir, San Diego County. 



Flow Maintenance Dams 



The construction of new stream flow maintenance 

 dams was stepped up somewhat during the biennium. 

 The Wildlife Conservation Board provided funds to 

 finance the major portion of this work. 



Nearly all of the new dams were constructed in two 

 of the State's most popular trout angling counties. El 

 Dorado and Tuolumne, where 20 were constructed 

 or enlarged during the two-year period. Table 47, 

 Appendix, lists the streams benefited by this work. 



