100 REPORT OF THE SECRETARY OF COMMERCE 
coast in winter, some traveling upward of 300 miles; while on the 
Gulf coast the winter movement is offshore, with a probable return 
to shallow water in the spring. Growth studies of the shrimp have 
been continued, and data have been collected for a report on the 
shrimp and shrimp fisheries of Texas. 
During the year extensive collections of eggs and larvae of im- 
portant commercial species have been studied, and a manuscript is 
being prepared which will set forth the characters by which these 
immature forms may be identified. The Pelican, a 73-foot Diesel 
ship, was transferred during the year to the shrimp investigation and 
will be used next season in offshore work. Aided by the life history 
studies now completed, it will be possible to determine the distribu- 
tion of larvae and young and possibly to discover basic causes for 
the fluctuations in abundance that disturb the fishery. With the 
Pelican, an attempt will also be made to discover whether the larger 
shrimp congregate in deep offshore waters after they leave the shal- 
lower areas in the fall and winter. If they are found to do so, an 
mmportant new fishery may be opened up. 
Pacific coast and Alaska fishery investigations.—Investigations on 
the Pacific coast and in Alaska are concerned mainly with the mainte- 
nance and rehabilitation of the salmon and herring fisheries of 
Alaska and the salmon fisheries of Puget Sound and the Columbia 
River. All of the major investigations in progress during the fiscal 
year 1936 were continued in 1937. 
In the Columbia River area the collection and analysis of catch 
records has been continued to determine the condition and trend of 
the commercial fishery, to demonstrate the extent of depletion of the 
supply if it prevails, and to establish a basis for proper regulation of 
the fishery. Excellent progress has been made on the stream-survey 
program, out of which is emerging a clear picture of the extent of 
available spawning areas, the location of barriers which may be 
removed or modified to permit the passage of fish, and the number of 
unscreened irrigation outlets that menace downstream migrants. A 
manuscript tracing the history and development of the fisheries of the 
Columbia and the parallel development of other natural resources: 
which directly or indirectly influence the fisheries has been prepared 
for publication. Studies of the migrations and the size and seasonal 
occurrence of the runs of salmon have been aided by tagging experi- 
ments performed during the year and by counts of migrating salmon 
passing through the three fish ladders at the Rock Island Dam and 
through weirs in the Okanogan and Wenatchee Rivers. 
In Puget Sound special attention has been given to determining the 
causes and extent of the decline in abundance of the sockeye salmon. 
These statistical and biological studies provide essential data for the 
scientific management of this seriously depleted fishery. The coho 
salmon of Puget Sound has been the object of special studies on 
rebuilding depleted populations through artificial propagation and 
transplanting of fingerlings. Marking experiments have been under- 
taken to determine the success of liberating hatchery-produced finger- 
lings of different sizes and of transplanting fish to “foreign” stream. 
systems. 
In Alaska the long-term studies of the red salmon runs of the Karluk 
River have been continued. One of the more important findings of the 
year was the accumulation of evidence indicating a positive correlation 
