68 U. 8S. BUREAU OF FISHERIES 
brown trout were made in the experimental stream, 13 of which 
were successful. The survival from plants of advanced fry and eyed 
eggs gave further confirmation of last year’s results. From a plant 
of 8,000 eyed cutthroat eggs, 465 fish, or 15.5 percent, survived after 
51 days. A shghtly higher survival of 21.7 percent was obtained 
from a plant of 2,000 unfed fr y. These results were obtained under 
hight predation, and survivals are slightly higher than any obtained 
last year. In contrast, a plant of 1,000 unfed fry showed a survival 
of only 1.4 percent under heavy predation, 64 wild trout being taken 
from this section at the end of the experiment. 
Brown trout fingerlings, planted at the usual size at which they 
are planted from “State hatcheries, showed surprisingly high sur- 
vivals after 3 months. For instance, in one section a survival of 
76.4 percent was obtained after 94 days, in spite of the fact that 117 
wild trout were also present in the section. These fish were planted 
at a length of 1.5 inches and averaged 3.2 inches at the end of the 
experiment. By way of comparison, wild brown trout of the same 
age, netted from Convict Creek, showed a survival of over 89 percent 
after 97 days under heavier predation, 
Small rainbow trout, averaging 1.7 inches in length, planted in 
two experimental sections, showed survival rates of 75.6 and 83.1 
percent, respectively, after 95 days. ‘These fish were planted without 
removing wild fish and no effort was made to protect them from 
other predators. 
One of the most surprising results has been the large numbers of 
naturally spawned fish that are found in the exper imental sections at 
the end of the season. This year a total of 1,123 wild brown, rain- 
bow, and eastern brook trout were removed from the 15 experimental 
sections, an average of 74 wild fish per section. 
Some much-needed j improvements were made during the past year, 
including the construction of a small cabin for living “quarters, and a 
few changes in the experimental section. Floodwaters in late June 
interfered with the experiments to some extent. Late in the fall a 
flood diversion ditch was constructed which will make it possible to 
divert at least a portion of high water out of the main channel and 
around the experimental area. 
Shasta Dam survey.—A party of four biologists, employed by the 
United States Reclamation Service, has been enga ged i in an investiga- 
tion of the salmon-salvage problems resulting from the construction 
of the Shasta Dam on the Sacramento River. This work is under the 
immediate direction of Dr. Smith. During the summer most of the 
spawning areas above the dam were located and measured to deter- 
mine the extent of such areas that will be destroyed upon completion 
of the dam. Streams below the dam were also examined for suitable 
spawning areas. 
On the basis of counts made of salmon passing over the fish ladder 
at the irrigation dam at Redding, it is estimated that there are 
approximately 20,000 salmon in the fall run alone, which would indi- 
cate a potential deposition of over 70 million eggs in the area that 
will be cut off by the dam. 
Dam debris survey.—tLate in June a crew of four men was em- 
ployed by the United States Engineer Corps to make a study, under 
the direction of Dr. Smith, of the fisheries problems arising from the 
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