BUREAU OF FISHERIES LZ 
has declined to a dangerously low level and that curtailment of fish- 
ing is necessary. The decline has been caused by the virtual failure 
of three successive broods, those of 1932, 1933, and 1934, combined 
with excessive fishing. Closure of the Cape Ommaney area was rec- 
ommended until the population shows definite signs of recovery. 
The fishery of the Prince William Sound and Kodiak areas continued 
at a high level of abundance, but since considerable expansion is con- 
templated, a close watch must be maintained to avoid over- 
exploitation. 
Collection, tabulation, and analysis of the daily catch records from 
the various types of fishing gear operated by the salmon fishing indus- 
try in Alaska have been continued. Indexes of abundance derived 
from these data are an important basis of recommendations for 
changes in the fishing regulations. 
Pilchard investigations —Although biologists of the Pacific Coast 
States have already collected a considerable body of information bear- 
ing on the migrations, spawning, and age and growth of the pilchard, 
the basic problem remaining for solution is the determination of: the 
optimum level of catch below which the stock would go to waste 
through underutilization, above which it would become reduced to 
commercial unimportance through overexploitation. To provide a 
basis for determining this level, the staff conducted studies dealing 
with the determination of abundance, age, and reproductive success, 
and with the importance of intermigration. 
The use of aerial observers in gaging abundance was tested but 
rejected as unsatisfactory. Changes in relative abundance are there- 
fore being determined by statistical analysis of the commercial catch 
records over a period of years. 
To discover how much the stock is reduced by fishing it is neces- 
sary to determine the ages of the fish making up the population each 
year, thus learning the relative abundance of the individual broods 
of previous years and how fast they are removed by fishing and by 
natural mortality. Age determination is being attempted by inter- 
preting marks in scales and otoliths, by observing the growth of 
young pilchards, and by identifying modes in frequency distribu- 
tions of the adult population. 
During the spring of 1939 several cruises were made in the spawn- 
ing and nursery grounds, quantitative samples of the young pilchards 
being taken. These cruises were made possible by the cooperation 
of the Scripps Institution of Oceanography, which furnished the 
vessel F. W. Scripps. When the surveys are completed, it is hoped 
that light may be thrown on the distribution and abundance of eggs 
and young, as well as on the effect of oceanic conditions on the 
success of spawning. 
To determine whether the pilchard stock in northern waters is 
self-perpetuating or is maintained by migrations from other areas, 
techniques are being developed for appraising the contributions from 
various spawning areas through study of the sculpturing on the 
scales. If the method proves valid, it will aid in determining how 
much fishing in specific areas affects the stock in other areas. 
Great Lakes fishery investigations —A state of critical depletion 
continues to exist among the more valuable commercial species of 
the Great Lakes. The extent of this depletion is apparent from 

