59 STAT.] CANADA-SOCKEYE SALMON FISHERIESJuly 21, 1944 1617 Aug. 5, 1944 RECOMMENDATION OF INTERNATIONAL PACIFIC SALMON FISHERIES COMMISSION FOR OVERCOMING OBSTRUCTIONS TO THE ASCENT OF SOCKEYE SALMON, PURSUANT TO TERMS OF A TREATY BETWEEN CANADA AND THE UNITED STATES The International Pacific Salmon Fisheries Commission was created for the purpose of rehabilitating a Pacific Coast salmon run known as the sockeye salmon of the Fraser River. In its largest year this run produced almost a quarter of a billion pounds of finest quality canned salmon which at present prices would have a value of more than forty million dollars. An eighth of that amount is now considered a good pack. Among causes suggested for this great decline were need for inter- national regulation and damage to the runs by blasting of rocks and by rock slides during railroad construction in the narrow gorge of the Fraser River, up which the fish must ascend to reach their spawning grounds. The first function of the Commission was to determine what were the actual causes, next to suggest remedies, and after eight years to regulate the catch. Sockeye salmon normally spawn in late summer or fall in gravel beds in streams which are near lakes, or in the lakes themselves in the upper Fraser River drainage area, some 90,000 square miles in extent. The eggs hatch in early spring, and the young usually spend a year in lakes, then go down to sea and when four years old return to the very stream in which they were born, then in turn to spawn and die. The production of each stream therefore depends upon the run to that stream four years before. In a big river system like the Fraser with its numerous feeder streams there are therefore many separate runs each year. These may occur at different times during a season, though in fact there is much overlapping of such runs. If the salmon had to keep on their way upstream or die and a run lasted only 30 days and there was a period of 30 days right at the time of such run when the fish could not pass up the river, the conclusion would be natural that such run would not reproduce itself. The problem is not that simple. However, the Commission did find that salmon could only stand a limited delay and that if the delay exceeded such limit they dropped downstream and were lost for reproductive purposes. The Commission further found that there were specific levels of the river during which the salmon were unable to get up through the terrific rush of water at Hell's Gate Canyon and that these impassable levels occurred during the salmon season, but varied greatly in time, length, and seriousness from year to year. In some years practically all the runs which had survived to that year got through. In other years the entire season was nearly impassable (in 1941 it is estimated that one
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