668 
BULLETIN OF THE BUREAU OF FISHERIES 
that the feeding salmon frequent the waters of the open sea as well as those of the 
immediate coast. Bigelow and Welsh (1924), in discussing the habits of the pink 
salmon transplanted in the coastal streams of Maine, state that: 
During their first months in salt water the fry linger near the mouths of the home streams, 
where they feed chiefly on copepods and other small crustaceans, or pteropods, and on insects 
that drift down stream with the current, and occasionally on fish fry. After they are 5 or 6 inches 
long they move out into deep water, and very little is known of their habits and wanderings there- 
after until they reappear on the coast as adults to breed. 
Since the Pacific salmon live alternately in two distinctly different environments, 
fresh-water and marine, their geographic distribution is influenced by the limiting 
factors in each environment. This study was made for the purpose of determining 
the geographic distribution of the salmon and gaining knowledge of the environmental 
limitations to their occurrence. 
GEOGRAPHIC DISTRIBUTION 
NATIVE 
The native distribution of the Pacific salmon is confined almost entirely to the 
temperate and arctic waters of the North Pacific. They are found in the streams 
along both the North American and Asiatic coast lines within similar geographic 
limits. On the North American continent O’Malley (1920), Cobb (1930), and Ever- 
mann and Clark (1931), give Monterey Bay, 70 miles south of San Francisco, Calif., 
as the southernmost limit of their common occurrence, although a few specimens 
have been taken at odd times as far south as the Ventura River, Calif. From here 
O’Malley (1920), Gilbert (1922), and Cobb (1930), report them inhabiting the coastal 
streams, in varying degrees of abundance, northward along the continent to Kotzebue 
Sound in Bering Strait. 
Dymond and Vladykov (1933) give the probable occurrence of chum salmon in 
the Mackenzie River of northern Canada and the definite occurrence of this species 
in the Lena River of northern Siberia. These rivers flow into the Arctic Ocean. 
From the Lena River, the northernmost point of occurrence on the Asiatic continent, 
they are found to a limited extent southeastward along the Arctic shores to the 
Chukchee Peninsula in Bering Strait. From the Anadir River just south of the 
Chukchee Peninsula all species, according to Caldwell (1916), Lebedev (1920), 
Russian Economic Monthly (1920), Baievsky (1926), and Pravdin (1932), are present 
in varying degrees of abundance in the coastal streams southward along the continent 
to the Amur River. The range of the pink and chum salmon extends farther south- 
ward to the Tumen River in northern Korea which is given by Mori (1933) as the 
southernmost occurrence of these salmon. 
All species other than the chinook salmon, according to Jordan, Tanaka, and 
Snyder (1913), Tanaka (1931), Handa (1933), Oshima (1933), and Tokuhisa and Ito 
(1933), are found in the coastal streams of Sakhalin, Hokkaido, and Kurile Islands 
and the northern shore of Honshu Island. The range of the pink and chum salmon 
extends farther southward on Honshu Island to the Tonegawa River near Cape 
Inuboye on the eastern shore, and to the Omonogawa River near Akita on the west- 
ern shore. A report has also been received through correspondence from Dr. Fujita 
of the Hokkaido Imperial University, of the limited occurrence of the chum salmon 
