66 U. §. BUREAU OF FISHERIBNS 
were made employing synthetic diets supplemented with liberal sup- 
plies of vitamin concentrates. Al recognized vitamins were included 
m these supplements but this mixture “could not replace the factor 
H of fresh meat. Present knowledge about the part any of the 
vitamins play in the growth and well- being of trout is extremely 
limited. 
New attempts were made to prepare concentrates of factor H from 
liver but with little success. Ten percent of fresh liver added to a 
synthetic diet seems to satisfy the requirements of trout for all vita- 
mins. In accordance with our earher studies it seems that liver 
retains part of its factor H when dried in vacuo. 
Studies with meats and fish preserved in various ways have been 
continued. Some success has resulted from feeding meat such as 
spleen preserved with salt. No injurious effects have resulted from 
feeding high levels of salt to brook trout. 
Since ordinary dry feedstuffs contain about 10 percent of moisture, 
an attempt has been: ene to dehydrate fresh meat by mixing it with 
very dry feed mixtures. By starting with a very dry diet ‘sufficient 
fresh meat can be added to bring the mixture to its normal content 
of about 10 percent. Preliminary tests with this method indicate 
that part at least of the factor H is preserved. 
Intermountain Region.—Fish management work in the Intermoun- 
tain Region in cooperation with the United States Forest Service and 
the fish and game commissions of the several States, which had 
been discontinued for several years, was resumed with the appoint- 
ment of Dr. Stillman Wright as regional biologist. Dr. Wright 
established his headquarters” at Logan, Utah, on June 9, where the 
State Agricultural College has very eenerously provided adequate 
laboratory facilities for him and his assistants. Since entering upon 
his duties Dr. Wright has spent considerable time familiarizing him- 
self with conditions in this region, in the course of which he has 
traveled approximately 17,400 miles by automobile. 
Trout are the principal game fishes of this region in which, as 
elsewhere, the number of anglers and consequent intensity of fishing 
is increasing very rapidly. Failure of the fisheries to maintain them- 
selves under the heavy demands of the public is evident in the 
streams, particularly those near centers of population. In lakes and 
reservoirs excessive removal of trout is usually followed by a great 
imerease in the less-desirable species. Factors other than over fishine 
are, however, involved in the general decline of the fisheries in this 
region. Silting, resulting from overgrazing and accelerated erosion, 
makes streams less suitable for trout. In many streams hydroelectric 
and irrigation projects interfere with normal migrations, while fluc- 
tuations ‘of the water level in reservoired lakes interferes with normal 
spawning and may have other detrimental effects. Because of the 
variety and critical nature of the many problems involved, it is 
evident that for some time investigations in this region must be 
directed toward the formulation of management plans for waters 
showing possibilities of immediate improvement of fisheries resources. 
During the past summer special attention was given to Fish Lake, 
Utah, which formerly supported a highly productive fishery for 
rainbow, mackinaw, and brook trout. Some years ago the Utah club 
was introduced and bas since become extremely abundant. As the 
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