534 U. S. BUREAU OF FISHERIES 
also were obtained from the Shumagin Islands and Golovin Bay. 
Study of the racial characters of the herring has disclosed the 
existence of local races, which knowledge will be of great value in 
drafting regulations, as it indicates the relative independence of the 
fishing areas. Weights of herring are being tabulated in an effort 
to determine when the herring in each locality reach a condition suit- 
able for packing. 
The present data, although not conclusive, indicated the presence 
of dominant year groups, which may be one explanation for the 
great fluctuations in abundance. Further study may show the possi- 
bility of foretelling such periods. The investigation is discussed at 
greater length on p. 650 of this report. 
During 1927 it is planned to continue the investigation, commencing: 
the field work in April with some experimental tagging and con- 
tinuing with the collection of samples in one locality throughout the 
season. 
FISHERIES OF INTERIOR WATERS 
COREGONINZ OF THE GREAT LAKES 
Dr. Walter Koelz has continued his investigations of the white 
fishes, and in addition to publishing Document No. 1001, “ Fishing 
Industry of the Great Lakes,” has completed the revision of the 
Coregonine, in which systematic relations and natural history of 
these fishes in the Great Lakes and Lake Nipigon are given in great 
detail, together with descriptions of several new species. This work,. 
which is now ready for publication, embodies the most extensive and 
complete study of coregonine fishes in North America that has ever 
been made and lays the groundwork for an understanding of fishery 
conditions in the Great Lakes as a basis for protecting these rapidly 
declining fisheries. 
The investigations on the herring of Lake Huron by Dr. John Van 
Oosten, described in the last annual report, were continued during 
1926. The statistical data on the catch having been found wholly 
inadequate, biological data were sought which might furnish some 
clue to the trend of the intensity of fishing. That this fishing is very 
intense is suggested by the paucity of old fish in the commercial 
catches. Herring are known to reach an age of 11 years, yet ex- 
tremely few individuals reach the sixth year of their life—the second 
year after most of them first join the schools of commercial sizes. The 
majority of the herring do not even reach the fifth year of life, 
and relatively few 3-year-old fish, many of which enter the commer- 
cial catches for the first time in the fall, escape the nets to return a 
year later as 4-year-old fish. 
The biological data indicate, by the shifting in the age composition 
of the commercial catches, that the intensity of the fishing has 
steadily increased in recent years. In 1921 the 4-year-old fish were 
more numerous than the 2-year-olds,-but since 1921 the former have 
become progressively less and the latter progressively more abundant 
each successive years So intense does commercial fishing appear to. 
be that a year class is virtually wiped out during its year of abun- 
dance in the commercial catches. Although at present the herring: 
