southern California north to British Columbia 

 were recaptured on all fishing grounds from 

 southern California to British Columbia. . . .Fish 

 tagged off central and northern Baja California 

 were recovered in large numbers in the south- 

 ern California catch, moderately in the central 

 California catch and negligibly in the catch of 

 the Pacific Northwest. No tags were recovered 

 from the two lots tagged and released south of 

 Sebastian Viscaino Bay, Baja California (i.e., 

 in Magdalena Bay and south) . 



'(b) Dispersal of tagged fish throughout 

 the range of the species is difficult to examine 

 in detail owing to lack of recovery facilities in 

 Baja California . However, the available data . 

 . . show that fish tagged off southern California 

 tended to move more to the north than did fish 

 tagged off central California tend to move south . 

 On the other hand, tags put off British Columbia 

 became increasingly more available to the 

 southern California fishery than to the British 

 Columbia fishery. Fish tagged in southern 

 California were equally distributed on all fish- 

 ing grounds . 



"(c) Fish tagged off Baja California, from 

 Sebastian Viscaino Bay northward, gradually 

 dispersed throughout the California fishing 

 grounds, and there was one recovery off Wash- 

 ington. Over three-fourths of the recoveries 

 were made in the southern California area, how- 

 ever. Owing to the greater distance from the 

 California fishing grounds, the dispersal was 

 slower in the first season after tagging. . . . 

 than for fish tagged off California. The total 

 number of returns per thousand (56.43 for Baja 

 California, 90 26 for southern California and 

 79.80 for central California) indicate, however, 

 that in the California fishery the ratio of Baja 

 California fish to California was 56.43/90.26 

 and 56.43/79.80 and thus the recovery rate of 

 Baja California tagged fish was 60 to 70 percent 

 of the California tagged fish . These percent- 

 ages reflect the relative availability of the Baja 

 California and California sardines to the U.S.- 

 Canadian fishery. 



"(d) The recovery of all tagged fish in 

 southern California in relation to the number of 

 fish taken in the commercial catch was 1 .5 

 times as great as in the central California re- 



gion .... As noted above, fish tagged off southern 

 California were recovered in all areas in about 

 the same proportion as the total catch and the 

 greater concentration of tagged members in this 

 area came from fish tagged off Baja California . 

 It might be concluded from this that the density 

 of tags was greater in fish tagged off Baja Cal- 

 ifornia than in fish tagged off central California, 

 and therefore the population off Baja California 

 was somewhat smaller than that off central 

 California during the period of tagging experiments . 



Growth characteristics: Data on the length 

 frequency distributions of sardines have been col- 

 lected almost from the inception of the fishery. 

 Not until the development of techniques for de- 

 termining age (Walford and Mosher, 1943a and b), 

 however, was it possible to study growth in any 

 detail. Subsequently, considerable attention has 

 been given to growth and related problems, es- 

 pecially by Phillips (1948), Landa (1953) and 

 Felin (1954). 



These studies have shown that there are 

 between- season, between-port and between -year - 

 class differences in "size on age curves. 

 Similarly, there are within -season, within-port 

 and within -year-class differences. Some of the 

 differences appear to be associated with latitude . 

 Insofar as the characteristics examined are con- 

 cerned, the sardine population, as sampled by 

 the fishery, is not homogeneous. The nature of 

 the observed differences is not definitely known, 

 but they are probably phenotypic . 



Spawning : If all sardine spawning took 

 place at a single time and in a single place, 

 then there would be no subpopulation problem 

 since there would be opportunity for gene flow 

 throughout the population . An important recent 

 addition (Ahlstrom, 1954) to our knowledge of 

 sardines is that there are at least four space - 

 time opportunities for separation between spawn - 

 ing sardines. These include: 



1 . Southern California offshore area: 

 An area extending roughly from Pt. Conception 

 to Pt. San Quintin and extending some 300 miles 

 offshore. The peak of spawning here occurs in 

 April -May in waters of 13 .0° -16 .5°C . 



2 . Lower California offshore area: An 



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