PROGRESS IN BIOLOGICAL INQUIRIES, 1926 521 
sened materially, however, by the heavy mortality of the older fish. 
The bureau’s efforts, therefore, are of great importance, for its 
studies on nutrition and diseases have made possible an increased 
output of the larger fingerlings from hatcheries that formerly suf- 
fered the ravages of disease. 
Studies of the Atlantic marine fisheries have been prosecuted with 
increased vigor. Contributions to the basic knowledge of the biology 
of the region have been made through studies of the fish fauna, 
plankton, and oceanography of the Gulf of Maine; the fauna of 
Chesapeake Bay; cod-egg production in Massachusetts Bay; and mi- 
erations of the adult cod on the shore and offshore banks. The key 
to the fluctuation in the mackerel supply also has been discovered in 
the phenomenon of dominant year classes. These investigations dis- 
close the fact that the mackerel in the tremendous catches of the 
past two years are the progeny of but two successful spawning 
years. It is believed that continued observations will make possible 
the forecasting of the immediate future success or failure of the 
mackerel fishery. 
The extent and effectiveness of the bureau’s investigations has been 
increased materially by the cooperation of various State departments. 
During the past year, work was conducted in cooperation with the 
States of North Carolina, Texas, Arkansas, Minnesota, Michigan, 
Wisconsin, Washington, Oregon, and California. The States pro- 
vided men, laboratories, boats, and other equipment, and have been 
enthusiastic over the results obtained. 
An important conference of the North American Committee on 
Fishery Investigations was held at St. Johns, Newfoundland, on 
July 9, 1926, for the purpose of further coordinating the efforts of 
the several nations interested in the fisheries of the North Atlantic 
region. Dr. H. B. Bigelow, Elmer Higgins, and O. E. Sette rep- 
resented the United States; W. A. Found, Dr. A. H. Leim, and H. E. 
Tanner represented Canada; and D. James Davies, A. C. Goodrich, 
and G. F. Sleggs were the Newfoundland representatives. No rep- 
resentatives from France or Portugal were present. The various 
fishery investigations were considered by the committee and recom- 
mendations of extension or modification were made in some cases. 
The importance of statistics in the codfishery of the entire region 
was dwelt upon, and plans for participation by Newfoundland in 
the investigation of the oceanography of that region were made. 
Undoubtedly the most serious handicap to the proper development 
of effective fishery conservation in the United States is the almost 
uniform lack of adequate statistics of the fisheries. While there has 
always been a more or less general realjzation of the economic value 
of records of total annual yield, the numbers of persons engaged, 
and the amount of investment in the fisheries, less attention has been 
given to the need for determining the relative abundance of the fish 
stock, year by year, as an indication of the state of the fisheries: It 
has been announced repeatedly that the aim of the division of 
scientific inquiry is to study fluctuations in the fisheries and to deter- 
mine their immediate causes; but in nearly every case it has been 
impossible to attack the problem from a quantitative standpoint, 
which is by far the most important aspect, because of the lack of 
suitable statistical data. The yield per unit of effort, such as the boat 
