TWENTY-EIGHTH BIENNIAL REPORT. 



61 



to the incoming of al)un(lant groups of sizes, which then from year 

 to year increase in length until lost in the mass of larger fish. They 

 furthermore show that there may be periods several years in length 

 during which the spawning is relatively unsuccessful. They can not, 

 however, follow the progress of these groups above twenty-two 

 centimeters. 



Their data show the passage of but one of these periods of poor 

 spawning, and there is no ground as yet for assuming any definite 

 regularity in the appearance of this phenomenon of dominant and sup- 

 pressed groups. On the contrary it is expected that these periods of 

 nonsuccess in spawning will vary greatly in length, and that at any 

 time there may ensue periods of such length as to, for the time being, 

 practically sweep out of existence the sardine fishery — for the smaller 

 sizes at least. This same thing has happened in European herring 

 fisheries. The advantage to the canners of keeping their product 

 diversified should be plain. 



of pounc/s 



200 



Fig. 14. Amount of sardines in total California catch, 1915-1923. 



It was also attempted by ]\Ir. Higgins to correlate the sizes of sardines 

 taken with the numbers of fish packed in the pound oval cans. He 

 reports that the changes observed in the catch by our sampling methods 

 are reflected in the pack of the canners. It is therefore possible to 

 prophesy the take. A tentative effort at prophesying the catch during 

 the season 1923-1924 was successful at San Pedro. There is nothing 

 at all remarkable in this, considering the firm basis upon which our 

 records are founded, and it is the conviction of the staff that we may 

 look forward with assurance to the time when very definite and valuable 

 forecasts can be given the canners. It is, however, felt that considerable 

 caution is yet necessary in the use of this possibility. 



