46 U. S. BUREAU OF FISHERIES 
EARLY LIFE HISTORY 
The study of the data on size composition has already shown a 
relation between temperature and incoming successful year classes, 
warm years being associated with their appearance in the fishery 3 
years later, cold years with their nonappearance. A report on this 
subject was prepared during 1938 for publication. 
Further investigation of the relation between temperature, or other 
environmental elements, and successful year classes should make it 
possible to predict 3 years in advance the relative size of year classes, 
and hence facilitate greatly an intelligent management of the fishery 
from the conservation as well as industrial viewpoint. 
Such knowledge requires a boat for the quantitative sampling of 
the young during their stages of random distribution, and for the 
study of conditions on the actual spawning and nursery grounds. 
For 1939, arrangements have been made with the Scripps Institution 
of Oceanography for a joint expedition on the research boat #. W. 
Scripps during May and June off the coast from California to British 
Columbia. The northern and western limits of the spawning range 
of the pilchard will be sought by the Bureau. Parallel observations 
on the hydrographic conditions will be made by Scripps Institution. 
This first cruise must of necessity be of a preliminary nature, and can 
be of far-reaching significance only when related to cruises made in 
other years and covering the entire pilchard-spawning season. It 
seems unlikely that such a program of marine work can be carried 
out unless a boat is at the year-round disposal of the investigation. 
ORIGIN OF THE COMMERCIAL SUPPLY 
To determine whether the stock in northern waters is self-perpetu- 
ating, young pilchards were sought along the Washington and Ore- 
gon coasts during the year. The stomachs of salmon and albacore, 
both predaceous, which presumably feed to some extent on pilchards, 
were examined at frequent intervals between March and December. 
In this manner young fish were found in April and, later, additional 
ones were collected by a beach seine in Willapa Bay, and others in 
a trap at Coos Bay. Though these collections may indicate some 
spawning in northern waters, the importance of such spawning in 
perpetuating the population found there is yet to be investigated. 
It is hoped to appraise the contributions from various spawning 
areas through study of the sculpturing on the scales. Preliminary 
examination has shown that the spacing of the ridges on scales 
appears to differ among young fish caught in different localities. If 
further work confirms preliminary observations, this would be a 
characteristic established early and preserved throughout life. It 
would constitute, in effect, a marking on the fish according to areas of 
origin, and suitable interpretation of it would provide an answer 
to question 3. This will require additional collections of young fish 
during 1939 in various localities from Mexico to British Columbia. 
The studies on the scales will be continued so as to determine the 
significance and utility of ridge measurements and age determina- 
tions. 
The program of work was carried out by a staff consisting of 
O. E. Sette, in charge of the investigations, Dr, L. A. Walford, 
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