BURPAU OF FISHERIES 313 
biological and economic purposes. Since the fisheries are usually 
prosecuted in areas not under private ownership, the problem of their 
conservation is of national concern. It therefore is important that the 
Federal Government keep close watch over the condition of the vari- 
ous fisheries in order that depletion may be anticipated in time that 
remedial measures can be successfully taken. Thus, current statistical 
data must be obtained on the yield of our fisheries. These figures 
furnish the biologist with the background from which he estimates 
future trends and yields. In addition to their value in the conduct 
of conservation studies, the Bureau’s statistical surveys form the basis 
for information of greatest importance to guide the fishery trade in 
the conduct of its business activities. 
Sectional surveys—The basic statistical surveys are those for the 
various geographical sections. These cover complete statistics of the 
volume of the catch of fish and its value, employment in fishing, quan- 
tity of fishing gear used, number and classification of fishing and 
transporting craft, employment in wholesale and manufacturing 
establishments, and the volume and value of manufactured fishery 
products and byproducts. The first comprehensive survey of this 
type was made for the year 1880. Surveys following 1880 until recent 
years were periodic, or covered a limited number of States or areas 
in any single year. Currently, however, complete statistical surveys 
of the commercial fisheries in all marine and lake sections are being 
made. Detailed tabular statements based on the sectional surveys are 
published annually. 
Landings at certain important United States ports—In addition 
to the basic sectional surveys, the Bureau also conducts various local 
or special surveys. These include the daily collection of data on the 
landings of fishery commodities by fishing vessels at the ports of Bos- 
ton and Gloucester, Mass.; Portland, Maine; and Seattle, Wash. 
Statistical data for the New England ports are recorded according to 
the fishing areas from which the catch is taken and gear used in cap- 
ture. Consequently, this information is most important in following 
the trend of the yield of the important North Atlantic species. Data 
on daily landings at Seattle are of equal importance in following the 
trend of the fisheries for halibut and other North Pacific forms. Data 
on these landings of fishery products are published monthly. 
Shad and alewife fisheries—Shad once entered the streams of the 
Atlantic coast, on their spawning migration, in much greater numbers 
than they now do. Two of the most important streams of present 
spawning migrations are the Hudson and Potomac Rivers. Conse- 
quently, in order that detailed data may be available for the study 
of these fisheries, annual surveys are made of the production of shad 
