GEOGRAPHIC DISTRIBUTION OF THE PACIFIC SALMON 
673 
these were found to have spawned and died in the usual way. A brief note in the last official year- 
book states that “a number exist in Lake Ohau, having acquired a landlocked habit. These fish 
run up creeks at the head of the lake and spawn there every season [year] in March and April.” 
Hatcheries have been constructed, and each year there is an abundant egg take. 
The eggs are hatched and the fry used to restock the parent stream or are planted in 
other streams on the island. Eggs collected and eyed in New Zealand have been sent 
to Tasmania for transplantation. Of the four successful foreign regions in the world 
to develop sea-run populations, New Zealand has been the most outstanding to date. 
The authors wish to acknowledge the kind cooperation of A. E. Hefford, Chief In- 
spector of Fisheries, New Zealand, in furnishing them with complete information 
concerning the history of the transplantation and development of the chinook salmon 
in the waters of New Zealand. Pictures of the chinook salmon and the streams in 
which they spawn, also scenes of the sport and commercial fisheries, are shown in 
figures 6-9. 
The sea-run populations of Pacific salmon that have been established in both 
Chile and New Zealand have adjusted their life cycle to the change in occurrence of 
the seasons in the Southern Hemisphere. The spawning migrations of these salmon 
occur in January, February and March which are the seasonal equivalents of July, 
August, and September in the Northern Hemisphere. The foreign regions into which 
the Pacific salmon have been introduced are shown in figures 1-4. The solid black 
areas indicate the regions in which the salmon have been transplanted successfully, 
and the dots show the regions in which transplantations failed. 
ENVIRONMENTAL LIMITATIONS TO OCCURRENCE 
During the first years of the introduction of the Pacific salmon into foreign waters 
very little was known concerning the proper methods for shipping or propagating 
these species. The failure of many transplantations to survive during this early 
period may have been due to excessive mortality in the eggs or unsuccessful rearing 
and planting of the young. However, with the improvement in fish-cultural methods 
the mortality during shipment and early propagation declined in importance so that 
following the year 1900 a high percentage of eggs shipped survived and the young were 
reared and planted successfully. This information was secured mainly through 
correspondence received from the various States and countries participating in this 
work. In view of this fact it is believed that the ultimate success or failure of these 
latter transplantations was dependent, to a high degree, upon the favorable or unfavor- 
able influences existing in the foreign waters in which they were made. 
NORTH PACIFIC REGION 
The environmental components of the fresh-water habitats in the native distri- 
bution of the salmon, which appear to be definite limiting factors, are temperature of 
water and character of stream bed. The degree of tolerance to temperature is much 
greater for the adults than for the eggs and young. The temperatures of the streams 
in which the salmon have been found spawning ranged from slightly above 0° to a 
maximum of 21°C. This range of temperature has been determined from recording 
thermographs operated yearly in Alaskan streams by the Bureau of Fisheries, and from 
stream surveys made by the Bureau’s biologists, in both the Pacific Coast States and 
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