TWENTY-EIGHTH BIENNIAL REPORT. 15 



cooperative agreement with the Federal Bureau of Fisheries. Most of 

 the staff is busily engaged in gathering statistics and in compiling 

 them. 



The main conclusions in the sardine work are as follows: 



1. In order to have an accurate picture of the commercial catch, 

 it is necessary to take samples at least twice a week. 



2. Studies of fluctuation show this phenomenon to be due to one of 

 two factors: 



(a) Presence of dominant age groups which may appear in cycles 

 of several years. 



(b) Diminution due to relatively unsuccessful spawning. N<d regu- 

 larity in this instance has been discovered. 



3. Reliable forecasts of the commercial catch can be made as a 

 result of statistical study. 



4. From available statistics, overfishing can not be readily detected 

 in time to prevent depletion. 



5. Since sardines are the source of food for albacore, barracuda, 

 sea bass and tuna, the effect of overfishing would be far-reaching. 



Further study of the albacore emphasizes the fact that migrations 

 are not concerned in the peculiarities of the fishery. So-called ''runs" 

 are not the result of migrations, but the result of schools already 

 present which begin to take bait at the surface. 



Studies have shown that albacore 2iyo inches in length are just 

 completing their second 3'ear; those averaging 27 inches in length are 

 finishing their third year; and those 38 to 40 inches in length are 

 in their eighth year or over. 



The purse seine investigation, when completed, brouglit out some 

 interesting facts. Up to 1915 there was but one purse seine boat; 

 thereafter, five were in service, and by 1920, over 100 boats were being 

 utilized in the fishery. Blue-fin tuna are taken only by the purse 

 seine boats, and the winter supply of barracuda, yellow-tail, and 

 white sea bass is largely dependent upon this part of the fishery. In 

 fact, over one-half of the fish reaching the fresh fish markets of Los 

 Angeles harbor is a product of this fishery. 



Attention is called to the fact that the grunion, the life history of 

 which was worked out by the laboratory, will sooner or later need 

 protection as grunion fishing is a popular sport on the beaches of 

 southern California. 



This year will see added to the files the fifth successive annual 

 statistical record of the daily catch. The total take by locality has 

 been published quarterly. These statistics are more complete than 

 those collected by any other government and will give a dependable 

 comparison of abundance in successive years, a fundamental need in 

 the proper development of fisheries. In addition, biological data as 

 to the varying composition of the catch in regard to sex, size, and other 

 features, has been assembled. 



EDUCATION AND PUBLICITY. 



The Department of Education and Publicity was very active during 

 the past biennial period, as shown by the report submitted. Many 

 more people were reached through the medium of lectures than in any 

 previous biennium. The work in the summer resorts has proved par- 



