PROGRESS IN BIOLOGICAL INQUIRIES, 1939 30 
trapped at Rock Island before hauling ceased, and few, if any, steel- 
head trout ascend the upper Columbia in the winter. During the 
May—December period 41,722 fish were hauled. The totals by species 
are as follows: Chinook salmon, 11,206; blueback salmon, 19,591; 
silver salmon, 13; steelhead trout, 5,427: squawfish, 1,771; suckers, 
3,389 ; a, 133; whitefish, 163; Dolly Varden trout, 1; carp, 2; 
tench, 1; and lamprey, 25. Every effort was made to. sort out the 
scrap fish, such as suckers, squawfish, etc., so that they would not 
be hauled ‘along with the salmon. This practice was in general suc- 
cessful, but all of the undesirable species could not be eliminated 
from the loads. 
Careful and complete observations and records were made of the 
entire salvage operations. The records included the number and 
species of all fish trapped and hauled each day in each truck, and 
to each location. The number and species of all fish that died during 
the hauling or trapping operations were also recorded. Temperature 
readings of the water in the Columbia River, the tank trucks, and 
the streams or lakes where plants were made, were obtained. Also, 
determinations were made of the free carbon dioxide, dissolved oxy- 
gen, pH and alkalinity of the Columbia River, the water i the trucks 
and in the streams where the fish were pl inted. After the fish were 
liberated, continuous limnological observations were carried on in 
the areas where the fish were confined. All dead fish were examined 
to determine whether or not they had spawned, and aquatic-food 
samples were taken from the streams. The success of the spawning 
was recorded and some of the nests were examined to discover the 
degree of development and the mortality of the eggs. Samples were 
taken of young steelhead trout from the early spring spawning so that 
growth could be studied. 
The loss of fish during trapping and hauling was extremely small 
and the mortality in the streams and lakes after the fish were lib- 
erated and before they spawned was not excessive, except in the Entiat 
River where a bacterial fungus infection caused a significant per- 
centage of the spawners to die before they had matured ‘and deposited 
their eggs. 
It is felt that the analysis of these data will contribute significantly 
to our knowledge of the habits of chinook and blueback salmon and 
steelhead trout, as well as present a valuable account of a practical 
fish-salvage operation. 
Tagging.—Five tagging experiments were conducted near the east 
end of Sand Island, at the mouth of the Columbia River, on blueback 
salmon from June 11 to July 9, inclusive. The purpose of these 
experiments was to obtain data on: (1) The rate of migration of the 
salmon upstream; (2) their distribution in the river system; and 
(3) some estimates of fishing mortality. 
During the operations 238 blueback salmon were tagged and lib- 
erated, of which 61, or 25.6 percent, were recovered from the 
commercial fishery. 
Additional catch records of the commercial fishery were tabulated 
and summarized to be used in studying the movements and abundance 
of the salmon populations. 
Construction of fish protective works—The program of fish-screen 
construction in eastern Washington, Idaho, and Oregon was con- 
