348 
BULLETIN OF THE UNITED STATES FISH COMMISSION. 
After the trout the greatest enemies to fry are perhaps the sea birds. Flounders 
and sculpins are too sluggish in their movements, besides being bottom fish, to be 
very destructive. Sudden storms, raising a heavy sea on the shore along which the 
fry are schooling, are also dangerous. 
The loss of the hatchery in the ratio of fry planted to the number of healthy 
eggs basketed it is believed at present will not amount to 25 per cent from all causes, 
although during the first season it was figured at not far from 40 per cent. The 
greatest present loss is from dead eggs and “empties,” or unfecundated eggs. This is 
not now as much as 15 per cent, and gradually diminishing as experience is gained. The 
loss from freaks and abortions and premature births, all combined, is nominal, but is 
greatest in the eggs of the spring run. It is not of itself considered a factor, but is 
lumped with the losses from other causes. Deaths due to smothering of the tiny fry 
during the period of absorption of egg sac, through injuries received in various ways 
while in the troughs and reservoir, with the other losses just mentioned, will make up 
a conservative total loss of 25 per cent. The superintendent believes his 1900 loss 
should not be much in excess of 20 percent unless from some unlooked-for calamity. 
The superintendent believes in the parent region theory, and thinks that the 
Karluk fishery has already this year (1900) felt the value and effects of artificial 
propagation. He thinks that the largest and strongest of the fry planted in the winter 
of 1896-97 and spring of 1897 have become matured, that this year they returned as 
breeders, and that their numbers were sufficient to make an appreciable increase in 
the runs of salmon schooling off Karluk Head, and possibly Ayakulik River. He 
believes they first put in an appearance as grilse, invariably males, which are 
thoroughly matured, and that these grilse are 2 years old, that is, from birth. Part 
of the breeders, he thinks, return in three years, while others of slower development 
return in four or five years, and it is not beyond the bounds of reason to presume 
that some may be delayed for an even longer period before reaching full maturity. 
In 1897 the adipose fin was cut from 513 fry, part of which were liberated in 
Karluk River and part in the lagoon. 
The approximate output of the Alaska Packers Association’s redfish hatchery at 
Karluk is estimated as follows: 
Fry liberated. 
Season 1896-97 2, 000, 000 
1897- 98 5, 000, 000 
1898- 99 5, 000, 000 
1899- 1900 6,000,000 
1900- 1901 12,000,000 
Total output 30,000,000 
