THIRTY-SEVENTH BIENNIAL REPORT 51 



provided to Jielp the tisli over otherwise insiirniountable dams, and suffi- 

 cient water must be maintained in the streams to provide passage. 

 Stream blocks such as Shasta and Friant dams and the proposed dams on 

 the American and Trinity rivers require adequate provisions for caring 

 for or salvaging the fish that will be stopped by these structures. 



Surveys have been made of spawning areas in the Central Valleys 

 streams. A count of the salmon spawning in the American River is being 

 made to estimate stream flows and spawning area necessary to care for 

 them. This work is now required, since the United States Bureau of 

 Reclamation has temporarily abandoned the Cross Delta Canal and has 

 substituted a series of three storage reservoirs on the American River 

 as a source of water to supplement the San Joaquin Valley supply. 

 Counts are planned to proA'ide similar information on the run in the 

 Trinity River, where another dam is noAV contemplated to supplement 

 the water supply in the Sacramento River Basin. 



Tagging of salmon has been continued to determine the relation of 

 the offshore fishing to the spa^vning stocks in various streams. Results 

 so far indicate that of the fish recovered from those tagged north of 

 Point Arena, over 50 per cent are taken in the Sacramento-San Joaquin 

 River system, w^hile 76 per cent of the recoveries from fish tagged south 

 of Point Arena are taken there. 



Measurements of the numbers of downstream salmon migrants lost 

 in large diversion canals was begun during the spring of 1942 as a logical 

 basis for the fish-screen program. Irrigation was started later than 

 normally, due to the unusual extension of the rainy season, so that results 

 were not significant, since most of the young salmon had left the streams 

 before the diversions being tested started taking water. 



SHARKS 



Records of the landings of sharks during 1940 and 1941 show a 

 decrease over the amount taken in 1939. The total landings were 

 7,813,000 pounds in 1940 and 7,511,595 in 1941. Legislation was 

 adopted by the 1941 Legislature which was calculated to stop the waste 

 of shark carcasses at sea, prevalent at that time. However, an unfor- 

 tunate wording of this law made it unenforceable, and the practice is 

 continued at the present time, except in districts where the market for 

 fresh fish can absorb the shark meat. An examination of the detailed 

 landings has indicated that approximately ten million pounds of sharks 

 have been taken off the coast of California each year. The discrepancy 

 in the recorded landings and the actual catch is due to the confusion 

 brought about through the practice of recording only the liver weights. 

 Therefore, the recorded decrease in landings over previous years can not 

 be considered as significant. 



Price of shark liver reached a high point in October and November, 

 1941, when $6 per pound was paid for the soupfin shark liver in Cali- 

 fornia. Accumulation of large stocks of oil and enforced conservation 

 brought about the issuance of Order No. L-40 by the War Production 

 Board and resulted in the complete collapse of the market in the spring 

 of 1942. With strict control of the utilization of vitamin A oils, there is 

 little prospect that such wild speculation as occurred in 1941 will occur 

 again. 



