134 REPORT OF COMMISSIONER OF FISH AND FISHERIES. 
the Nushagak. Lieut.Commander Tanner, U. S. Navy, who made the. 
inspection, found that a double trap was being built upon the Wood 
River, about 20 miles above its mouth and 40 miles from the Nushagak 
cannery. The Wood River at this point is a swift-running stream of 
clear, cold water, between 700 and 800 feet wide and 10 to 14 feet deep. 
Operations had not progressed sufficiently to indicate the character 
and extent of the work, but the plans contemplated an opening in mid- 
stream 100 feet wide, flanked on each side by a trap 40 feet square, 
with wings extending from the latter to the shores. The report of Lieut. 
Commander Tanner was submitted to the Secretary of the Treasury, 
who decided that the proposed traps were obstructions to the ascent 
of salmon within the meaning of the law, and that their erection was 
therefore illegal. 
Although the salmon-eanning industry of Alaska is of very recent 
origin, the amount of capital invested in it is nearly $4,000,000, while 
the output in 1889 was valued at about $3,000,000, which is greatly in 
excess of the value of the yield of seal skins on the Pribilof Islands before 
the reduction was made in the number of seals that are allowed to be 
killed annually. That the salmon industry in that region is capable of 
very much greater development is unquestionable, as the resources 
have been tapped at only a comparatively few places, but, unless the 
fishery is carefully guarded, sooner or later there will be repeated in 
Alaska the same unfortunate condition of affairs which has obtained in 
every country where salmon have been abundant. The salmon spend 
most of their time at sea. The spawning instinct leads them into fresh 
waters, which furnish the necessary conditions for the hatching of the 
eggs and the development of the young during a portion of their exist- 
ence. The different species vary more or less in the date and duration 
of the spawning season and in their spawning habits. Some enter by 
preference the smaller streams, and others the larger rivers. Some 
never return to the sea, dying soon after having accomplished their 
reproductive functions, while others may survive to return again in a 
subsequent season. This habit of running up the rivers makes them 
fall an easy prey to the fishermen, especially if the river be small or 
shallow, or be restricted near its mouth. It is evident that if a river 
channel be closed against their ascent no spawning can be accom- 
plished in it, and from what is known of their habits it is also prob- 
able that the fish will not seek another river the same season. They 
remain below the obstruction, unable to make progress, but still guided 
by the common impulse to arrive at the spawning-grounds. Smaller 
barriers and large nets, of one character or another, accomplish the 
same result, although on a lesser scale, as they are generally arranged 
to retard whatever fish are not captured. 
The fishing season is, to be sure, restricted in its duration, and in 
this fact the fishermen find an excuse for resorting to their wholesale 
