94 U. S. BUREAU OF FISHERIES. 
It is quite plain that the saimon runs entering the Columbia River 
and the Strait of Juan de Fuca can not long continue to exist under 
this terrific drain upon the immature and mature fish. In the latter 
section the sockeyes and humpbacks are rapidly bemg exterminated, 
and it is probable that the chinooks and cohos, the especial victims in 
this attack, will soon show signs of exhaustion. 
The State authorities appear to be helpless in these matters, but an 
enactment by the Federal Government could be maintained, as the 
principle has been applied to fishery matters elsewhere, notably the 
spring mackerel closed season for five years and the sponge law relat- 
ing to the landing of undersized sponges taken from the grounds off 
the Florida coast. 
Next to the fishing operations of man, the gravest danger to the 
salmon fisheries of the Pacific coast lies in the pollution of the rivers 
which the salmon ascend for spawning purposes. The salmon, both 
old and young, require pure cold water, and the immense runs which 
have annually ascended the streams for many years are doubtless 
due to the fact that such conditions have prevailed in them. The 
large increase in the population of the coast States within recent 
years, with the resulting increase of mills and factories, has greatly 
increased the amount of sewage from cities and towns and the waste 
of the manufacturing plants. Many of the latter have also con- 
structed dams without adequate fishways, and these also wreak great 
havoc to the industry by cutting the fish off from the upper reaches 
of the rivers upon which constructed. 
The emptying of sewage into streams ought to be made. a crime. 
It is an exceedingly crude method of dealing with it, and, instead of 
disposing of the filth, merely transfers it from one place to another, 
making the water unfit for use at pomts farther downstream and 
spreading diseases and death amongst not only the finny but also 
human users of it. 
In the present condition of sanitary science it is a comparatively 
easy matter to dispose of this filth by modern septic devices, and a 
number of cities are now disposing of their sewage in this manner. 
The wrigation ditch, a comparatively new product on this coast, 
while of great benefit in developing the arid lands in certain sections, 
as at present operated is a considerable menace to the salmon fisheries. 
But few ditches have screens at their head, and as a result many 
thousands of young salmon slowly making their way to the ocean 
home pass into and down these to an early doom. Every owner of 
such a ditch should be compelled to place at its head a screen with 
fine enough mesh to prevent absolutely the passage through the 
same of even the tiniest baby salmon. 
Next to man and his methods the trout is undoubtedly one of the 
eres enemies of the salmon. The Dolly Varden follow the salmon 
rom the sea to the spawning beds, and when the eggs are extruded 
devour countless thousands of them. Many and many a time the 
writer has seen on the spawning beds female red salmon swimming 
around with a cloud of trout spread out behind like a fan, following 
her every movement, eagerly waiting for the moment when the eggs 
shall appear. 
In the summer, when the young are heading for the sea, the trout 
are lying in wait for them and again take their toll of countless 
thousands. 
