CALIFORNIA (Cont. ) 



15. Sacramento-San Joaquin River Salmon and Steelhead Study 



This study has two objectives: first, to estimate and evaluate losses in 

 irrigation diversions of seaward migrant salmon and steelhead; second, to 

 study the steelhead and its fishery in the Sacramento River to determine if 

 it is economically feasible to improve steelhead angling in this river system 

 by stocking yearling hatchery fish. Creel census, trapping, and the examina- 

 tion of fish at a fish ladder on Mill Creek and at Coleman Hatchery on Battle 

 Creek are being done to determine the contribution of the marked hatchery fish. 

 During 1956, a total of 270, 500 yearling steelhead were marked and released. 

 Tagging studies, in conjunction with the marking experiments, are making it 

 possible to determine the number of adult steelhead migrating into the upper 

 Sacramento River, the number taken by anglers, and the proportion of hatchery 

 fish in the population as well as the catch. 



U. S. Fish and Wildlife Service, California Kamloops , Inc. , and Steelhead 

 Unlimited cooperating; Sacramento-San Joaquin Valleys; began October 1952, to 

 close June 1959; $45, 000; Leo Shapovalov, Leader; reports available. 



Address inquiries to: As in No. 1 above. 



16. Stream and Lake Improvement 



The objective of this project is to improve lakes and streams in order to 

 increase the production and/or utilization of game fish. Some of the methods 

 used to achieve the objective include fish population control through use of fish 

 toxicants and other means; removal of log and debris jams acting as barriers 

 to migrating fish; construction of pool-creating devices in streams; and 

 control of excessive aquatic vegetation by chemical, mechanical, or other 

 means. 



Considerable time has been spent testing the new weedicides under various 

 California conditions and where various species of game fishes are present. 



Statewide; began March 1952, continuing; $50, 000; E. D. Bailey, Leader; 

 reports available. 



Address inquiries to: As in No. 1 above. 



Stanford University, Department of Biological Sciences 



Metabolism Rate Variations of Bluegill Siinfish 



The objectives are: (1) To determine the effect of body weight, temperature, 

 and activity on the rate of oxygen consumption. (2) To determine if seasonal 

 rates of oxygen consumption vary for given body weights, temperatures, and 

 activities. (3) To explain, if possible, late summer weight losses of larger 

 fish and stunting of smaller fish at a time when food appears in short supply 

 on the basis of metabolism rates. 



Felt Lake, Stanford University Campus; began March 1956, to close June 

 1957; Rogelio Juliano, Leader. 



Address inquiries to: Donald E. Wohlschlag, Natural History Museum, 

 Stanford University, California. 



Seasonal Envirnomental Effects on the Population Dynamics of a Natural 

 Predator-Prey Relationship 



The objectives are: (1) To determine the quantitative seasonal changes 

 in rates of recruitment, growth, and death, and also changes in population 

 size of a predator-prey fish combination (largemouth bass and bluegill) over a 

 period of three years. (2) To evaluate rates of change of biological production. 

 (3) To ascertain the possible magnitude and extent of causal environmental 

 factors influencing seasonal and annual changes in population statistics. (4) To 

 examine existing mathematical population models and relate them, with modi- 

 fications if necessary, to actual conditions of existence. 



