PROGRESS IN BIOLOGICAL INQUIRIES, 1939 33 
tions indicate, however, that east of the Mississippi River the shrimp 
do not confine their movements within State boundary lines. Shrimp 
tagged in Louisiana were recaptured in Mississippi; Mississippi re- 
leases were taken both in Alabama and Louisiana; and Alabama 
shrimp were returned from both Mississippi and Louisiana waters. 
The shrimp tagged and released to date must be regarded as only 
a beginning of an extensive program. The highly variable character- 
istics of almost all aspects of shrimp life ‘and behavior make an 
unusually large amount of data necessary in order to approximate 
more closely the average. To obtain a complete picture of the move- 
ments in the Gulf populations the tagging should be extended to 
the eastern limit of the fishery, near Carrabelle, Fla., and westward 
along the Texas coast. The young shrimp inhabiting the inland 
marsh areas should be marked to follow their growth rate and to de- 
termine the factors influencing their egress to the fishing grounds. 
A considerable number of large spawning shrimp should ‘be perma- 
nently branded to determine the possibility of their living more than 
1 year, and to follow their spawning movements. The ‘accomplish- 
ment of these objectives will require a period of several years and 
will necessitate the tagging of many thousands of shrimp. 
NORTH PACIFIC AND ALASKA FISHERY INVESTIGATIONS 
Dr. FREDERICK A, DAVIDSON, in charge 
The North Pacific and Alaska fishery investigations, with head- 
quarters in the Fisheries Biological Laboratory at Seattle, Wash., 
are concerned with the solution of problems that arise in the mainte- 
nance and rehabilitation of the salmon populations of the Columbia 
River and Puget Sound and the salmon and herring populations of 
Alaska. All of the major investigations that were in progress in 1938 
were continued in 1939. 
COLUMBIA RIVER 
The enon of the biological and physical factors influencing 
the populations of fish inhabiting the Columbia River and its tribu- 
taries was continued during 1939 by J. A. Craig, A. J. Suomela, M. G. 
Hanavan, Z. E. Parkhurst, rate 1. Rucker, and J. R. Coleman. 
Since it was necessary to detail practically the entire personnel of 
this investigation to the fish-salvaging work, it was not possible to 
conduct any stream surveys during 1939. 
Migratory fish salvage-—The Grand Coulee irrigation project, now 
being carried out by the Bureau of Reclamation, U. S. Department 
of the Interior, makes necessary the erection of Grand Coulee Dam 
across the Columbia River at a point some 128 miles up-river from 
Wenatchee, Wash. This structure will be about 330 feet high, from 
river level to crest, when completed. Because of the great height of 
the dam, it was decided that it would not be feasible to pass adult 
migratory fish over the dam on their upstream journey, nor their 
offspring over the structure in their downstream migration. 
Since this situation prevailed, and since significantly important 
runs of chinook and blueback salmon and steelhead trout normally 
proceed upstream beyond Grand Coulee Dam, it was necessary to 
devise and carry out plans for the protection or salvaging of these 
