VITA.L smTisncs 



Source Data 

 Total catch. - The hasic data for this central branch of research 



are the experiences of the fishermen themselves. Their "'Total catch" 

 is needed indirectly to derive "Intensity of fishing." It is used also 

 to compute "Vital statistics," a connectijon which is not shown in the 

 diagram. These statistics are collected by the several Pacific Coast 

 States and the Province of British Columbia as a matter of administrative 

 routine. 



Boat operation. - Records of activity, particularly of the time spent 

 fishing, would be invaluable for computing "Catch=per-unit=of -effort," 

 as it would permit by-passing two adjustments and would avoid an addi- 

 tional difficulty inherent in statistics of "Catch"=per-boat-week:,*' Un- 

 fortunately, records of boat operation are lacking except for a very small 

 sample resulting from an observer's interviews with fisherraeno Kftiether 

 or not these interview-data may be pressed into service in lieu of more 

 complete operational records remains to be seen. 



Boat -catch-records » - For the time being, the records of individual 

 daily landings by fishing boats, are the main reliance in deducing changes 

 in abundance or in availability of the pilchards from time to time and 

 from place to place. These records collected by the State and Provincial 

 Governments, give only the quantity of sardines in each delivery to the 

 processing plants. In California, each delivery represents one night or 

 a fraction of one night of fishing, in the Pacific Northwest, from a frac- 

 tion of a day to several days of fishing. In neither region is there any 

 record of nights or days spent in fruitless effort. 



Length samples . - "Length samples" cover the measurements and desig- 

 natlons of sex of a sample, usually 50, of individuals, from a delivery 

 of sardines. In California, prior to the season of 1941=42, semi -weekly 

 samples from 5 deliveries were taken by the California State Fisheries 

 Laboratoryo Sine© thenj, daily samples up to ten in number were taken by 

 the California State Fisheries Laboratory at San Pedro and Monterey and 

 by the Fish and Wildlife Service at San Francisco. Supplementing these 

 are special series of 100-fish samples collected by che Fish and Wildlife 

 Service at San Francisco and Monterey daily over certain periods during 

 the three seasons prior to 1941-42. In the Pacific Northwest, sampling 

 has been somewhat less systematic. In British Columbia, the Fisheries 

 Research Board of Canada has taken one 100-fish sample as nearly daily 

 as feasible. In Washingtonj, the Fish and Wildlife Service in some seasons 

 and the Washington Fisheries Department in others hav6 collected one to 

 several 50- to 100-fish samples daily. In Oregon, the Oregon Fish Commis- 

 sion has taken one to several 50- to 100-fish samples sometimes daily 

 and sometimes intermittently. 



