14 REPORT OF COMMISSIONER OF FISH AND FISHERIES. 



ARTIFICIAL PROPAGATION. 



The Chinook being the principal salmon that has been propagated 

 artificially, the following chapter is devoted almost entirely to this 

 species. The discussion of the apparatus and methods has special 

 reference to the hatcheries of the United States Fish Commission on 

 the McCloud Eiver and Battle Creek, tributaries of the Sacramento, 

 although cognizance is also taken of the work at the stations in the 

 basin of the Columbia River and on the short coast rivers of California 

 and Oregon. 



In 1896 the number of eggs of this fish collected by the Commission 

 was 36,237,000, from which about 32,000,000 fry were hatched and 

 planted. The collections of eggs of the silver salmon numbered 298,137, 

 which yielded 298,000 fry, and of steelhead eggs 604,000, which pro- 

 duced 499,690 fry. 



CAPTURING ADULT SALMON. 



The adult salmon from which eggs are obtained for the purposes of 

 propagation are taken chiefly with drag or sweep seines, this being 

 the most practical method of collecting them in large numbers. The 

 seines at the United States Fish Commission station at Baird, on the 

 McCloud River, are from 120 to 170 feet long, made of about 28-thread 

 twine, and are 20 feet deep in the middle, tapering down to about 

 6 feet at the ends; tbey are double-leaded on account of the swift 

 current of the river, and have a 4-inch mesli. In the rack iilaced 

 across the river to stop tlie passage of fish it is customary to build 

 large wooden traps in which to capture salmon, and at times, espe- 

 cially during a rain storm accompanied by a marked rise in the river, 

 large numbers of salmon are taken, but at other times only a few, 

 while there is never more than a small percentage of sj^awning fish 

 secured in this way. 



The trap is quite a valuable auxiliary to the seine, but can not be 

 relied on exclusively. Although it will secure many unripe fish, the 

 ripe ones, which are the ones that are wanted, finding an obstruction 

 in their way, settle back to spawning-grounds below and remain there. 

 The trap is simjily a square inclosure of vertically placed slats, with 

 an entrance similar to that of an ordinary pound net. The fish in 

 their eager efforts to pass upstream, go through the V-shaped mouth of 

 the trap, and having once entered, are not able to find their way out. 

 Boards are placed over tbe top of the trap to prevent the fish from 

 leaping out. 



Large dip nets have been used occasionally at Clackamas station, in 

 Oregon, the fishermen standing on the rack at night and dipping below 

 it. Toward the end of the season this method secures a considerable 

 number of ripe fish, but it involves much labor and expense, and most 

 of the spawning fish taken with the dip nets would probably have been 

 captured in the regular course of fishing. There being no satisfac- 

 tory seining-grounds at Clackamas, and the river just below the rack 



