fishing was of negligible importance; however, in the 

 winter of 1957-58 crappie were providing the most 

 successful angling in the area. The average catch per 

 angler effort was about five crappie, compared with 

 an average catch of 0.06 crappie in 1950-51. 



The effect of the shad on the important channel 

 catfish population of the Colorado River was not 

 well defined. There were some indications that growth 

 had improved slightly; however, the pre-shad growth 

 rate was so variable because of other environmental 

 factors that the response to the improved forage fish 

 supply was obscured. Since knowledge of the biology 

 of the shad is fundamental to a complete evaluation 

 of its effect in the Colorado River and its possible 

 effects in other California waters, it was imperative 

 that life history data be secured rapidly. 



The food habits, growth rates, reproductive char- 

 acteristics, and early development were investigated. 

 These data were utilized to predict the possible con- 

 sequences of an introduction of shad into the Sacra- 

 mento-San Joaquin Delta. It was concluded that the 

 benefits from such an introduction would outweigh 

 any possible harm to existing delta fisheries. 



Tagging Studies 



The development of adequate methods for obtaining 

 accurate measurements of the mortality rates within 



Threadfin shad (larger one eigh* inches^ token from on Imperial Valley 

 Irrigation ditch that drair\s into the Saltan Sea. 



— Fish and Game Photo 



fu//-grown gulf crooder from the Saltan Sea. Introduced as food lor 

 larger game fish, this small ocean species from Mexico's Gulf of Cali- 

 fornia is now the principal food of larger corvina. 



— Fish and Game Photo 



California's natural warmwater fish populations re- 

 ceived considerable attention. This type of informa- 

 tion is difficult to secure; nevertheless the demand for 

 such data is urgent in view of greatly expanding fish- 

 ing pressure, particularly in Southern California. 



Mortality data can best be obtained through tag- 

 ging studies, consequently much effort was expended 

 on the development of efficient tags and tagging tech- 

 niques. Sutherland Reservoir, a municipal water sup- 

 ply reservoir in San Diego County, was established 

 as a test water for tag experimentation. Complete 

 creel censuses, in connection with a largemouth bass 

 tagging study, were operated during the 1956, 1957, 

 and 1958 fishing seasons. The results demonstrated 

 that the disk dangler tag, used in the department's 

 successful catfish tagging studies, is also the most suit- 

 able tag for largemouth bass. 



The Sutherland Reservoir experiments will even- 

 tually show how largemouth bass populations react to 

 various levels of fishing and at what level the popula- 

 tion should be harvested to obtain the best fishing 

 during following years. 



Economic Value 



An estimate of the economic value of fishing in 

 California's warmwater lakes and reservoirs was de- 

 termined by personal interviews in 1956, in co-opera- 

 tion with the California Department of Water Re- 

 sources. The expression of warmwater fishery values 

 in monetary terms is vital to the proper planning and 

 development of water projects. It was found that an 

 average of 1 12.50 was spent daily by largemouth bass, 

 crappie, sunfish, and catfish anglers. The total annual 

 recreational value, in terms of actual cost to the an- 

 gler, of warmwater fishing in California was about 

 $46,000,000. 



Central Valleys Hatchery and Chino Fisheries Base 

 continued their roles as the centers for warmwater 

 fish salvage and transplanting. Appendix Table 35 lists 

 the number of fish. The great difference in totals be- 



