74 



DEPARTMENT OF FISH AND GAME 



A h\draulic drive mechanism for i<ccping screens free 

 from trash, rccentl\- de\cloped by department per- 

 sonnel, lias been simplified and improved. 



Coordinates Program 



To make most efficient use of shop facilities in Re- 

 girins I and II a member of the headquarters staff co- 

 ordinates the program and establishes state-wide prior- 

 it\- for screen and ladder construction and installation. 

 Screen activities have been confined mainly to the 

 northern part of the State, where serious losses of 

 young salmon and .stcelhead trout occur in irrigation 

 diversion canals. Perforated plate type screens were 

 installed in 23 water diversions in Siskiyou and Trinity 

 Counties in addition to maintaining existing screens. 



An outstanding innovation in fish screen design, an 

 automatic safety gate, was developed by Ernest Mur- 

 phe_\- of the Yreka shop. This gate is opened auto- 

 matically by a float arrangement when the water level 

 on the downstream side of the screen drops appre- 

 ciably, insuring a full flow in the diversion even in the 

 event of mechanical failure in the cleaning mechanism. 

 Several irrigation districts and other water users, form- 

 erl\- opposed to screen installation in their canals, were 

 fa\orabl\- impressed with the design, and approved 

 installation of screens equipped with the new gate. 



Among the projects of the Elk Grove shop was 

 remodeling of ladders at Clough Dam, and the lower 

 dam of the Los .Molinos Mutual Water Company on 

 Mill Creek in Tehama County. Two fish ladders on 

 the Stanford-V^ina Dam on Deer Creek in the same 

 count\' also were renovated. Federal aid project crews 

 repaired fish ladders on Sweasey Dam on A'lad River 

 in Humboldt County, and on Van Arsdale Dam on the 

 Eel River in Mendocino County. Jumping pools were 

 added to the San Geronimo Creek ladder in Marin 

 Count\', and on the Old Creek ladder in San Luis 

 Obispo County. 



Louver Type Screen 



A louver t\'pe fish screen patterned after U. S. Fish 

 and Wildlife Service experimental installations at 

 Trac>', built at the Elk Grove shop, was tested at a 





water diversion on Deer Creek in Tehama County. 

 This installation consisted of a series of vertical baffles 

 placed diagonally across a channel with a bypass open- 

 ing at the downstream end of the structure. Fish re- 

 sist the change in water velocity through the openings 

 between the baffles or louvers and are carried along 

 the line of louvers into a bypass. 



While young salmon and yearling steelhead trout 

 were successfully deflected by this device, trash grad- 

 ually accumulated on the vanes, causing considerable 

 head loss in the canal. It is believed that the debris 

 problem can be solved either by using wider spacing 

 between the individual louvers to allow trash to drift 

 through the screen or by developing a cleaning device 

 for intermittent operation when the head loss at the 

 screen reaches a predetermined point. 



SEISMIC EXPLORATIONS 



Department of Fish and Game personnel continued 

 to act as observers on all offshore seismic oil explora- 

 tions conducted by use of explosives, and to report 

 all observed damage of marine life. Each seismic ex- 

 ploration crew is accompanied at all times by an offi- 

 cial representative of the department, whose principal 

 duty is to observe the operation and take whatever 

 steps are necessary to keep damage to marine life to 

 an absolute minimum. Oil companies holding seismic 

 permits from the Fish and Game Commission must de- 

 fray costs of the department observers. 



From July 1, 1952, until June 30, 1953, there was 

 but a single oil survey crew working in California's 

 coastal waters. During this period the crew detonated 

 1,414,790 pounds of black powder with an observed 

 kill of 614 fish representing about a dozen species. 

 During the second half of the biennium, July 1, 1953, 

 to June 30, 1954, one seismic crew operated the entire 

 time, a second operated from July 28 to A'lay 31, a 

 third from December 2 through A4ay 31, and a fourth 

 from January 6 through May 20. These four crews 

 set off a total of 4,533,080 pounds of black powder 

 with an observed kill of 2,057 fish. In addition a fifth 

 crew, in the spring of 1954, carried out some experi- 

 mental work under special permit from the Fish and 

 Game Commission. 



In addition to seismic permits which allow the use 

 of black powder only, several permits were granted 

 various construction companies for use of high explo- 

 sives to remove pier structures, build sewer outfalls 

 and control teredos. Few of these operations lasted 

 more than two or three days but a department em- 

 ployee was on the spot to observe and oversee the 

 operation and report all observed damage to marine 

 life. 



Crob traps being set from a fypical crab boat off cenfral California. 



