158 REPORT OF THE SECRETARY OF COMMERCE 
comparisons of present-day production of certain species with yields 
of earlier years. In Lake Michigan, for example, production of 
wall-eyed pike, lake herring, lake trout, whitefish, and yellow perch 
varies from 43 to 62 percent of normal. Production of Lake Supe- 
rior whitefish is only 10 percent of normal. In Lake Huron produc- 
tion of perch and chubs is 44 and 36 percent, respectively, of normal. 
In Lake Erie production of nearly all important commercial species 
is on the decline, and total production of Lake Ontario is only 10 
percent of normal. 
Members of the Great Lakes staff cooperated actively with State 
and Federal officials and with sport and commercial fishermen, par- 
ticipating in an advisory capacity in 19 meetings and conferences in 
which Great Lakes fisheries problems were under consideration and 
assisting State conservation officials in the drafting of fisheries 
regulations. 
At the request of the Office of Indian Affairs of the Department 
of the Interior, a survey was made of the fisheries of Upper and 
Lower Red Lakes in Minnesota to settle various controversies con- 
cerning the regulation of the commercial gill-net fishery. Recom- 
mendations for the management of the fishery are being submitted. 
The report of the International Fact-Finding Commission on Lake 
Champlain was largely completed. The report will contain a dis- 
cussion of the fisheries controversies, a tabulation and analysis of all 
available information concerning commercial fishing and angling, 
descriptions of the natural history of the various species, a critical 
historical review of the artificial propagation of wall-eyed pike and 
yellow perch, and recommendations for the regulation of the com- 
mercial and sport fisheries of the lake. 
Age and growth studies of the whitefish of Lake Huron and Lake 
Champlain were completed for publication, and life-history studies 
of the yellow perch were continued. 
AQUICULTURAL INVESTIGATIONS 
The work of the aquicultural investigations continued along three 
principal lines: The development of means to obtain the maximum 
production of food and game fishes consistent with environmental 
conditions, the improvement of methods of artificially propagating 
and rearing fish, and the control of fish parasites and diseases. 
Investigations were conducted in trout waters to obtain definite 
information on the annual drain to which the trout population is 
subjected by anglers and the value of artificial stocking in maintain- 
ing a stable fish population. Such studies were conducted through 
the operation of test waters in Vermont; experimental stocking of 
streams in the Pisgah National Forest where fishing is closely super- 
vised and an accurate check on returns may be obtained; and the 
operation of the Convict Creek experimental stream in California. 
These studies have demonstrated that in some situations natural 
propagation is superior to artificial in maintaining a stock of trout 
under adverse conditions and have emphasized the necessity of reg- 
ulating planting operations in accordance with the amount of nat- 
ural food present in the streams. 
