PROGRESS IN BIOLOGICAL INQUIRIES, 1938 49 
The activities of the Great Lakes staff were again characterized 
by active cooperation with State and Federal officials and with sport 
and commercial fishermen. Certain of the cooperative projects will 
be described later in this report. During the year Dr, Van Oosten 
acted in an advisory capacity at 19 meetings and conferences in which 
Great Lakes fisheries problems were under consideration. He also 
continued to assist State conservation officials in the drafting of 
proposed fisheries regulations. 
The Bureau gratefully acknowledges the cooperation of the Uni- 
versity of Michigan in providing laboratory space and extending 
numerous other courtesies to the staff. 
STUDIES OF ABUNDANCE 
Dr. Ralph Hile has completed the routine computation of 1937 
indexes of production, abundance, and fishing intensity for important 
commercial species in each of the 20 statistical districts of the State 
of Michigan waters of the Great Lakes. The assignment of a 
W. P. A. project to the Great Lakes laboratories has made possible 
the tabulation of valuable production statistics for the several fishing 
districts over the 18-year period, 1891-1908. These compilations are 
being made from original records loaned to the Bureau by the Michi- 
gan Department of Conservation. 
AGE AND GROWTH STUDIES 
Lake Huron whitefish—A study (in press) of the Lake Huron 
whitefish, Coregonus clupeaformis, by Dr. Van Oosten included in- 
formation on growth rate, growth compensation, the age and year- 
class composition of the stock, the sex ratio, age at maturity, the 
relationship of total and standard length, the length-weight relation- 
ship, and the coefficient of condition. The Lake Huron whitefish 
grows most rapidly in the first year of life, but a secondary period 
of rapid growth occurs in the fourth year. Growth compensation 
occurs during at least the first 7 years of life. The collection of the 
summer of 1923 was dominated by age-group IV (1919-year class), 
and the fall collection of 1924 was dominated by age-group VI (1918- 
year class). The sexes were equally abundant in the collections as a 
whole, although the males tended to become relatively less numerous 
with increase in age. Sexual maturity was attained by nearly all 
males in the fifth year and by females in the seventh year. A single 
curve was found suitable to express the length-weight relationship 
of both males and females. There was, nevertheless, a noticeable 
tendency for females to be heavier than males of the same length, 
and for whitefish taken in the summer of 1923 to be in better condi- 
tion than those collected in the fall of 1924. 
Lake Champlain whitefish—A. paper entitled “The Age, Growth, 
and Food of the Whitefish of Lake Champlain” by Drs. Van Oosten 
and Deason is now in press. The materials consisted of scale samples 
and records of weights and measurements of 120 whitefish taken in 
northern Lake Champlain in 1930, and 175 individuals taken in 
southern Lake Champlain in 1931, and of the stomachs of 141 white- 
fish, also collected from southern Lake Champlain during the fall 
of 1931. The data suggested that the natural size and age compo- 
