20 U. S. BUREAU OF FISHERIES 
depletion of the supply is occurring from overfishing, and to estab- 
lish a basis for proper regulation of the fishery to permit an adequate 
escapement of adult fish for spawning. 
2. A stream survey of the Columbia River system to determine the 
extent of available spawning areas; to discover barriers to fish migra- 
tion and to provide for their removal or modification to permit pass- 
age of fish; to locate unscreened irrigation outlets; and to deter- 
mine the productive capacity of the various streams with respect to 
quantities of fish food and the physical and chemical conditions 
favoring or hindering the development of young salmon. 
3. Research into the history and development of the fisheries of 
the Columbia and studies of parallel development in other natural 
resources, such as water power, agriculture, lumbering, and mining, 
which may have either directly or indirectly influenced the fisheries. 
4. Studies of the migrations of salmon by means of tagging experi- 
ments. 
The collection and analysis of catch records during recent years 
and currently is being undertaken for comparison with historical 
records to show the extent to which the fishery resources have de- 
clined and the part overfishing may play in reducing the total 
population. During 1936 a considerable amount of routine work on 
tabulating the original catch records collected in 1935 was accom- 
plished. The extensive data which include records of the fishery 
from 1897 to 1935 are now ready for the final analysis which will 
indicate annual and seasonal fluctuations in abundance of the com- 
mercially important species comprising the catch of the Columbia 
River fisheries. Summaries and tabulations have been completed for 
the records of chinook, blueback, and silver salmon; and the greater 
part of the steelhead fishery records have also been summarized. The 
major portion of the work during 1936 has dealt with fish other than 
the chinook salmon, because the compilation of catch records for 
that species was virtually completed in 1935. 
The final report on the history and development of the Columbia 
River fisheries is nearing completion. This study demonstrates the 
importance and extent of the Indian fishery before the advent of 
white men on the Columbia and shows the fishing methods employed 
by the Indians. It also traces the growth of the salmon fishery 
from its early beginning when explorers and settlers salted a few 
fish to the great canning industry of the present day. The evolu- 
tion and, operation of each type of gear in use on the Columbia, 
canning methods, and the development of markets for the finished 
product have also been investigated. 
A tagging experiment was conducted for the purpose of obtaining 
data concerning the fall run of chinook salmon which passes through 
the commercia! fishery in the Columbia in the latter part of August 
and during September. The results of this experiment provide data 
relative to the speed of migration of this run after it enters the 
river, the minimum distances which the fish travel upstream, the 
proportion of the run which returns to hatcheries and possibly some 
measure of the intensity of the commercial fishery above the point — 
of tagging. 
This is the second tagging experiment that has been conducted 
on the fall run of chinooks in the Columbia River. The first was 
