PROGRESS IN BIOLOGICAL INQUIRIES, 1938 63 
TROUT 
It is the purpose of the investigations on 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 main- 
taining a stable fish population. Attention is also being given to 
the correlation between normal production and the available food 
supply and other factors which must be given consideration in de- 
veloping management policies. 
Lest streams.—The scientific work at the Pittsford (Vt.) station, 
under the direction of R. F. Lord, was again chiefly concerned with 
studies on test waters. Waters set aside for this purpose include 
three streams and one lake operated in cooperation with the State Fish 
and Game Service. On one of these streams, Furnace Brook, a 
State game warden was stationed each week end to examine anglers’ 
catches for marked fish and to obtain data on the lengths and weights 
of all trout taken from the stream. 
On both Furnace Brook and the South Branch of Middlebury 
River the total catch for the season was considerably less than in 
previous years. Unfavorable conditions during the winter of 1937-38, 
when heavy winter rains raised the streams to flood stage with 
much damage from floating ice, are believed to have been the cause 
of the exceptionally poor stream fishing throughout the State. 
The superiority of rainbow over brook trout in contending with 
adverse conditions is again brought out clearly in the results from 
Furnace Brook. As pointed out in previous reports, no rainbows 
have been planted in Furnace Brook for years, while the stream is 
heavily stocked each year with fingerling brook trout and, for several 
years past, with yearling brook trout as well. Nevertheless, the 
catch of brook trout has shown a gradual decrease each year while 
the decrease in the catch of rainbows has been comparatively slight, 
with the result that the proportion of rainbows rose from 34 percent 
in 1935 to 388 percent in 1937. In 1938 this trend was accelerated ; 
rainbows increased to 62 percent, while brook trout provided only 
38 percent of the catch. Furthermore, the average catch of rainbow 
trout per angler, which had remained constant during the preceding 
years at 2.4, in 1938 jumped to 3.7. 
The returns from 5,200 yearling brook trout planted in Furnace 
Brook in the fall of 1937 were very disappointing, only one percent 
of these fish being reported by anglers. The 1937 record of only 
12 percent recovery was thought low but it remained for adverse 
wintering conditions to show how a fall plant of yearlings could be 
total loss. 
Fish population studies were made on the three test streams in 
cooperation with the United States Forest Service. The procedure 
was to block off a section of the stream with seines at the upper and 
lower ends. These were weighted with stones so as to prevent any 
fish entering or leaving the section. A dam of burlap sacks filled 
with sand was then constructed across the upper end of the section 
so as to divert the water into another channel. Any pools that could 
not be drained were pumped dry so that every fish present could 
be captured. The average number of trout per acre in three sections 
of Furnace Brook was 835, with a total weight of 385 pounds, 11 
