198 U. S. BUREAU OF FISHERIES 
BIOLOGICAL ASPECT 
The biological aspect must be considered as two problems—the 
conservation and sustained supply of the resource, and the prediction 
of future trends or yields. Since the fisheries are usually prosecuted 
in areas not under private ownership, the problem of the conservation 
of these fisheries is of national concern. It is important that close 
watch be kept over the condition of the various fisheries in order to 
detect depletion, so that remedial measures can be promulgated 
timely and wisely. For this reason it is imperative that current 
statistical data be obtained on the yield of our fisheries. 
These statistics furnish the biologist with a background upon which 
to base his prediction of future trends and yields by coupling these data 
with studies of the life history of the species. Difficulty is experienced 
in making these predictions because the supply (population) of the 
species cannot be seen, as is the case with farm animals or crops. 
The more complete and reliable the statistics on yield are, the better 
foundation the biologist has for conducting his studies. The Bureau, 
therefore, attempts to obtain a complete picture of each individual 
fishery to further these biological studies. 
ECONOMIC ASPECT 
When the fishery has been conserved, and trends and yields of the 
fishery have been predicted, the problem still, remains of supplying 
the fishery trade with the information so essential to the conduct of its 
business activities. In these days of increased competition the very 
existence of the fishery industry must depend upon reliable economic 
and statistical information. Such material has been especially 
valuable during the past few years, when it has been used in national 
planning. The Bureau endeavors to make its statistical surveys so 
complete that the industry and the various governmental organiza- 
tions may turn to it for reliable fishery statistics. 
SURVEYS CONDUCTED 
The statistical surveys during 1939 were conducted under the imme- 
diate supervision of Edward A. Power, Associate Statistician, who was 
assisted by R. T. Whiteleather, Associate Marketing Agent. The 
statistical surveys were conducted under the general direction of Fred 
F. Johnson, Assistant Chief of the Division. These surveys included 
the collection and dissemination of statistics of the commercial catch 
and its value, fishmg craft and apparatus, and employment in the 
fisheries. In addition, data were collected on employment and com- 
pensation of those engaged in, and products of, fishery wholesale and 
manufacturing establishments. 
Surveys were made during the year covering all coastal sections as 
well as the Great Lakes and a portion of the Mississippi River for 
1938. Statistics of the fisheries of Alaska were collected by the 
Division of Alaska Fisheries. 
In addition to the above, statistics were collected on the following 
special phases: The landings of fish by United States fishing vessels 
at the ports of Boston and Gloucester, Mass., Portland, Maine, and 
Seattle, Wash. (published monthly); the catch of mackerel in the 
North Atlantic fishery; the cold-storage holdings of frozen and cured 
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