The migration pattern of the adults through Delta waters has 

 not been determined by direct investigation. However, returns from 

 marked salmon recoveries made at Paladini Fish Company in Pittsburg, 

 California, have contributed some knowledge of the migration pattern 

 of the Sacramento run of fall spawning salmon. In the fall of 1°U8, 

 UU adult salmon previously marked at the Coleman Salmon Hatchery as 

 seaward migrants were recovered from the commercial catch landed at the 

 Paladini Fish Company. Nine of the marked salmon were taken in gill 

 nets drifted in the San Joaquin River below the mouth of the Mokelumne 

 River. These recoveries indicate the possibility that 20 percent of 

 the Sacramento River salmon may return to their spawning grounds via 

 San Joaquin River and then through Three Mile or Georgiana Sloughs. 

 The principal upstream route is via Sacramento River. 



In 19h9 price disagreements between the packers and the fishermen's 

 union prevented duplication of the previous years inspection of salmon 

 landings at the Paladini Fish Company for marked fish and further study 

 of adult salmon movements through the Delta, 



No evidence of the migration pattern of the San Joaquin River king 

 salmon has been obtained. It is assumed that the principal upstream 

 migration is via Old River since approximately two-thirds of the San 

 Joaquin River flow is carried by it during the fall runoff. 



Seaward Migration 



Two separate studies of the seaward migration of king salmon 

 from the Sacramento River drainage have been made in the past. Rutter 

 (1902) made the first systematic study at Walnut Grove and Balls Ferry, 

 January 7 to May 8, l899« Hatton (19U0) and Hatton and Clark (19^2) 

 of the California Division of Fish and Game conducted a survey during 

 the years 1939<> 19^0, and 19hl at Hood, California. The present in- 

 vestigation began by using methods similar to those of Hatton. 



The pattern of the downstream migration of Sacramento River king 

 salmon in 19U7 is best illustrated by the following summary of fyke 

 net results obtained at Toland's Landings 



Month 



No. of Salmon 

 Percent of Total 

 Mean Monthly Runoff c, 



~19~W 



f .s 



December 

 f 9 

 1.0 



, 17100 



19U7 



January February March April May 



2 207 319 87 2 



.3 33oO 51.0 13.8 .3 



127UO 23390 30170 2ii220 10790 



Although the annual runoff of Sacramento River in 19^7 was 5k percent of 

 the fifty-year normal, the peak flows occurred in their historical runoff 

 pattern, and the downstream movement of the juvenile salmon migrants from 

 the Sacramento drainage conformed with this flow pattern. 



13 



