ALASKA SALMON INVESTIGATIONS TN 1900. 
347 
from the large nursery pond and planted; or, if the nursery he frozen over, they are 
taken from the reservoir and parent troughs, where they have been held on this 
account. After the fry are three or four months old it lias been observed that they 
seem to deteriorate in the nursery ponds, and they are never held beyond this time. 
When the ponds and upper part of the lagoon are frozen over, the fry are placed 
in tanks prepared for them, transported on sleds to the open water, and planted. 
These tanks are made of clean, strong, salt-salmon barrels thickly coated with 
asphaltum varnish and rigged with handles, or beckets, of rope. Three of these 
are a sled load, and comprise a “plant,” which usually numbers about 100,000 by this 
method. When the ponds and lagoon are open and free from ice, the fry are driven 
out of the rearing-pond at high water, through a short flume, into a live-car made of 
an old skiff. This skiff, which has a number of square ports cut in its sides, covered 
with tine mesh wire netting, is brought directly under the short flume, which leads 
from one corner of the pond to the lagoon beach. It has a capacity of over 200,000 
fry. When the live-car is loaded the wire-screen gates are let down across the inner 
end of the flume and the further exit of fry stopped. 
Planting is done at high water along the shores of the lagoon between the mouth 
of the river and the upper end of the village at Karluk. The location selected 
depends upon the existing conditions, ice, waves, and the movements of predatory 
species being considered. As far as possible a rocky shore whose crevices afford safe 
retreats, away from the entrance of fresh water where trout are attracted, is chosen, 
and the fry released without further preliminaries. It is claimed that no salmon fry 
has ever been planted at Karluk with the egg sac not entirely absorbed. 
The superintendent firmly believes that the strong free-feeding fry early crave 
.salt water, and he usually has a barrel containing a small quantity of salt submerged 
in the large nursery pond. It has been observed that the fry collect about this like 
flies after sweets, and the salt appears to act upon them like a tonic, making them 
more sprightly and vigorous in their movements. 
After being set free the fry have been observed to work downstream alongshore 
toward the salter portions of the lagoon, which is fairly brackish except at the higher 
tides, when it is cpiite salt, or at the lowest tides when the river is full, when the 
lagoon is practically fresh. Later the fry are seen along the outside beaches in the 
vicinity of the shaded rocky points, but return to the lagoon at frequent intervals, 
working in and out with the tides for a long time, or until late in the fall following 
their birth. Some fry are much stronger and larger than others and grow very 
rapidly. Two or three were seen in the nursery pond August 8, 1900, which were 
from 2 to 3 inches in length and very timid. In April, 1897, fry from If to If inches 
long were seen in small schools passing seaward from Karluk River, and the fry 
hatched in the spring of 1898 were from If to If inches, some 2 inches, in length in 
the nursery pond in August. 
Trout are believed to be the most destructive natural enemies the fry have to 
contend with. An individual ( Salvelinus malma ) only 2f inches in length which 
once found its way into the nursery pond had 12 tiny fry in its maw when captured. 
The trout are not such active feeders in the winter, and are more sluggish in move- 
ment, and it is therefore deemed advisable at Karluk to plant fry at this season. 
Other natural dangers are also believed to be lessened at this time. 
