636 U. S. BUREAU OF FISHERIES 
Such studies are now being conducted on the Karluk and Chignik Rivers and at Alitak 
in Alaska, and at Cultus Lake in British Columbia. These must be continued at least 
until the more fundamental factors affecting the fluctuations in production have been 
determined. It will be impossible to conduct such studies on all salmon streams, espe- 
cially on such large rivers as the Fraser and the Columbia; but it is believed that im- 
portant principles may be discovered by the intensive studies on these selected streams, 
which will be of universal application. 
STREAM SURVEYS OF THE SPAWNING GROUNDS 
These, as conducted on the Fraser, Rivers Inlet, Skeena, and the Nass Rivers by Mr. 
Babcock, and in the Bristol Bay region by Mr. Winn, and others, are valuable as a 
substitute for escapement counts, where these last are impossible. They provide a 
fairly satisfactory measure of the escapement and the extent to which the spawning 
grounds are seeded. 
STUDY OF THE PRODUCTION OF SEAWARD MIGRANTS FROM KNOWN ESCAPEMENTS 
OF PARENT FISH 
This is being done by actual counting at Cultus Lake, in British Columbia, and the 
Bureau of Fisheries is attempting to get some measure of the number of seaward migrants 
at Karluk through marking experiments. It is important as a means for determining 
whether the greatest fluctuations in mortality occur during the fresh-water life or in 
the ocean, and will also serve as a measure Of the results of conservation measures (such 
as artificial propagation) applied during the life in fresh water. 
EFFICIENGY OF VARIOUS METHODS OF ARTIFICIAL PROPAGATION, AS COMPARED WITH 
NATURAL PROPAGATION 
This line of investigation is one of the most practical and is designed to improve the 
present methods of fish culture. Intensive experiments are being conducted by the Bio- 
logical Board of Canada, and extensive marking experiments have been conducted by the 
Bureau of Fisheries and the States on the Columbia, Klamath, and Sacramento Rivers. 
Not the least important phase of this work is the study of the differences in the effi- 
ciency of natural propagation under varying conditions. Very few reliable data on this 
point are available, and a united effort should be made to discover the facts. 
EFFECT OF TRANSPLANTATION 
This is of very great practical importance on account of its bearing on the possibility 
of restoring depleted runs by artificial propagation. Experiments designed to test the 
effect of transplantation on the return of salmon to the tributaries of a large system are 
being conducted by the California Fish and Game Commission on the Klamath River. 
Some of the marking experiments conducted on the Columbia River will touch this 
problem, and others are planned in British Columbia. 
IMPROVEMENT OF SPAWNING AREAS AND OVERCOMING OF OBSTACLES, NATURAL AND 
ARTIFICIAL, TO THE ASCENT OF SPAWNING SALMON AND TO THE DESCENT OF THE 
SEAWARD MIGRANTS ° 
Under this heading by far the most important question is that pertaining to the 
possibility of providing efficient passageways for both adult and young salmon over 
high dams. It is imperative that a solution to this problem be reached in the near 
future, if possible, else the salmon runs in some of our more important streams will be 
destroyed, or at least reduced to a point where commercial fishing will be unprofitable. 
It is recommended that a subcommittee be appointed to consider the advisability of 
making a complete study of this whole question. 
THE LIFE HISTORY IN FRESH WATER, WITH PARTICULAR ATTENTION TO THE 
FACTORS AFFECTING SURVIVAL DURING THIS PERIOD OF THE SALMON’S LIFE 
. If we are to control, to any extent, the survival of young salmon in fresh water, it 
is essential that we know the causes of the fluctuations in the rate of mortality. It is 
important that we know the optimum conditions for the development of the eggs and 
young and the effect of variations in weather, water stages, temperature, chemical 
composition of the water, abundance of food, abundance of enemies, etc. This includes, 
necessarily, a study of the rate of development of the eggs, the growth and habits of 
the young, and allied problems. In addition to their bearing on the problems of natural 
propagation these questions also have to do with the problems of fish culture, and in 
that respect are of immediate practical value. 
LIFE HISTORY IN THE OCEAN 
Although many of these problems will be difficult of solution and must be deferred 
indefinitely, it is important, for the sake of completeness, that they be included in the 
program. The questions of the optimum conditions for survival in the ocean, habits, 
food, enemies, distribution, factors affecting migrations, factors affecting the onset of 
sexual maturity, etc., are all important to a thorough understanding of the fluctuations 
in mortality rates during the life in the ocean; but since they are not, apparently, subject 
to any control by man, these problems do not appear to this committee to be of prime 
practical importance. 
