18 ARTIFICIAL PROPAGATION OF PACIFIC SALMONS. 



At Bakor Lake the fish are taken in a web trap as they enter the 

 lake and are impounded in a slough at the head of the lake and held 

 there successfully for several months. When mature, they are re- 

 moved from the inclosure by means of a drag seine. 



AMiere immature salmon are to be held for any length of time, an 

 inclosure with a soft, muddy bottom should be provided for the pur- 

 pose, it having been found by experience to be far superior to a 

 gravel bottom. 



A rather novel method is employed for capturing silver salmon 

 and steelheads where the barrier preventing the ascent of the fish 

 chances to be a dam or a natural fall. At an advantageous point, 

 where the water pours over the crest of the barrier and where the 

 fish are known to jump in their attempt to ascend the river, a device 

 known as a jumping box is installed, being placed back of the fall 

 at a sufficient height, so that when the fish jmnp they will be likely 

 to fall through the water into it. The length of this box or trough 

 is governed by local conditions; its width varies from 18 to 24 inches, 

 and it is given a fall of at least 12 inches to each 10 feet of length. 

 A covered flume with a sharp fall connects it with a live box, which 

 is placed in the stream in such a manner as to insure its protection 

 so far as possible from high water, and at the outlet of the flume 

 leading to the live pen a downstream V is placed. This, together with 

 a secure cover, serves to prevent the escape of the fish from the pen. 



In the operation of this contrivance the fish fall into the jumping 

 box, and before they can regain their equilibrium they are carried 

 into the live pen and are held there until removed. Care must be 

 taken to prevent overcrowding in the pen, as, when the fish are jump- 

 ing from G to 9 a. m. and from 3 in the afternoon until sundown, 

 they are apt to be taken in such numbers that loss from smothering 

 will result, unless the pen is emptied at frequent intervals. 



TAKING AND IMPREGNATING THE EGGS. 



When chinook-salmon eggs are taken on a large scale, say from 

 a half million to three or four millions per day, as is customary at 

 the Little "VMiite Salmon station on the Columbia River, spawning 

 usually occurs daily throughout the egg-collecting season, it being 

 impracticable to hold the fish in pens for any length of time, as they 

 injure themselves more or less in fighting against confinement, and 

 many eggs are dropped. 



The females are placed in pens by experienced men, and ripe 

 ones only are put in. Of the signs that indicate ripeness in a female 

 salmon the separation of the eggs in the ovaries is the surest. Spe- 

 cific signs are all fallible, however, and the spawn taker must rely 

 mainly on an indescribable ripe look, which is neither color, shape, 

 nor condition of organs, but a general appearance which shows at 

 a glance that the fish is ripe. This knowledge can be gained only by 

 experience. 



An attendant gets into the pen containing the females and catches 

 a fish by the tail with his left hand, on which is worn a woolen 



flove or mitten as an aid in maintaining his hold. He kills the fish 

 y a blow on the head with a club and, casting it on the trap floor, 

 repeats the operation until from 40 to 50 have been killed. At some 

 stations it is customary to cut off the tails at the base of the caudal 



