Fishery bulletin of the Fish and Wildlife Service - NOAA

ABSTRACT
T7XCEPTIONAL DATA are available for the study of the salmon runs of the Columbia
-•—i River in 1938. Detailed figures on catch were supplied by Oregon and Washington in
such form that they could readily be combined with the counts at Bonneville Dam to provide
a basis for estimating the escapement. Tables show the catch of each species for each week
in each of six zones, and the counts at Bonneville and Rock Island dams. The general
course of the run of each species is shown. The numbers of fish bound for the spawning
grounds above Rock Island Dam are estimated as follows: Chinook salmon entering Columbia
River before May 1, 4 percent; during May, 6 percent; June and July, 15 percent; and
August to December, 1 percent. Blueback salmon entering the river during the above
periods, 40 percent. Steelhead trout entering the river during June to September, 1 percent;
during the rest of the year, 10 percent. Fishing intensities are shown by escapement to
catch ratios. Percentages of Chinook salmon escapement are less than 15 during May; 17
during June and July; and 33 during the remainder of the year. The June and July runs
are now greatly depleted, and an important part of these runs spawns above Rock Island
Dam. The blueback salmon escapement is about 20 percent, and of steelhead trout about
33 percent. Weekly and seasonal closed periods are shown to be almost entirely ineffective
for increasing the spawning escapement. Exploitation is further increased by the intensive
troll fishery conducted from Monterey Bay to southeastern Alaska. Chinook salmon are
also subjected to a sport fishery of considerable importance. Main runs of salmon to the
Columbia River are practically unprotected and are fished with destructive intensity.