40 U. S. BUREAU OF FISHERIES 
Studies pertaining to the continuation and well-being of the pink- 
salmon runs in Alaska were conducted at the Biological Station in 
Seattle and the summer field station at Little Port Walter, Alaska. 
The field station was opened on June 21, 1938, and continued in 
operation until October 20, at which time the season’s work was 
completed. A number of factors pertaining to the life history were 
investigated, and stream surveys and other types of aquatic biological 
studies were carried out. 
A tagging experiment was conducted to determine the migration 
routes of pink salmon passing through Lower Chatham Strait, 
Alaska. Some 2,095 mature pink salmon taken from the com- 
mercial fish traps in Tebenkof Bay, Kuiu Island, were tagged and 
released. Of the total number tagged, 637 were recaptured by the 
commercial fishery, a return of 30.4 percent. The experiment is to 
be repeated in the summer of 1939 and when all recovered tags are 
collected, information will be at hand covering the routes of migra- 
tion taken by both the even- and odd-year pink-salmon runs. 
The salmon-counting weir was installed across the stream at Little 
Port Walter, and a sexing pen was constructed in front of the 
counting gate to determine the number of male and female salmon 
in the run. The first of the run passed through the weir on August 
28. This was the latest date for the appearance of the run since 
the installation of a counting weir at Little Port Walter, the run 
being a full week after the latest observations previously recorded. 
The males entered the stream in greater abundance during the early 
part of the season, but by the close of the season the females had 
almost equaled their number. <A total of 3,283 males and 3,184 fe- 
males entered the stream, bringing the total to 6,467 salmon on Sep- 
tember 22, the close of the season. Previous weir-count totals of 
salmon entering the stream at Little Port Walter have consisted of 
6,952 pink salmon in 1934, 6,073 in 1935, 5,164 in 1936, and 7,085 in 
1937. From these figures it would appear that the run has been 
able to maintain itself at a more or less fixed level of abundance in 
this locality during the past 5 years. 
After the adult salmon had entered the stream to spawn, a series 
of gravel samples were taken from 28 nests of spawning fish to 
determine the size and type of rubble selected. Im computing a 
percentage mean for each gravel size, and using all of the samples, 
it was found that 6.88 percent was 3-inch gravel or over; 5.79 per- 
cent was 214-inch gravel; 8.38 percent was 2-inch; 10.80 percent was 
114-inch; 14.82 percent was 1-inch; 7.57 percent was 34-inch; 12.75 
percent was 14-inch; 8.76 percent was 14-inch; and 24.76 percent was 
sand aggregate that passed through a 14-inch screen. Nesting areas 
composed of gravel over 3 inches in diameter are not selected when 
areas of the finer aggregate are available, but, owing to crowded 
conditions, nest building and spawning sometimes take place in 
Jarge rubble. 
In February 1938, a C. C. C. camp was moved from Juneau, 
Alaska, to Little Port Walter, under the supervision of the Forest 
Service. C. C. C. personnel worked at the station all spring and 
summer clearing ground, building a dock and float, moving build- 
ings to higher ground, constructing 3 miles of forest trail, and build- 
ing two shelter cabins on the headwater lakes at Little Port Walter. 
