Cobh. — Protecting Migrating Pacific Salmon. 151 



cause the owners of the dams were unwilling to allow the in- 

 stallation of anything that required any considerable cutting 

 into the dam. One of these provided for a tunnel under the 

 apron and the dam itself, and the installation of an enclosed pool 

 and fall fishway along the upper side of the dam, with an open- 

 ing upstream at the crest of the dam. This opening was to be 

 safeguarded from debris and was to be provided with gates for 

 controlling the supply of water entering therein. The entrance 

 to the fishway was to be at the head of one of the deeper pools 

 in which the fish generally congregated. 



SAFEGUARDING THE YOUNG ON THEIR SEAWARD WAY. 



After provision had been made as noted above for the ascent 

 of the adult fish, it was necessary to safeguard the young fish 

 on their way to the sea, their natural habitat. 



When the course of the river was unobstructed the little 

 fish usually came down stream in schools in the late spring and 

 early summer. When small tributaries were encountered many 

 of the fish would ascend these for some distance, or play around 

 inside their mouths, to later resume their interrupted journey. 

 For irrigation purposes large ditches, some of them carrying an 

 immense volume of water, are constructed and the entrance to 

 these is at one or the other side of the dams. They are pro- 

 tected by large gates, which are raised to a height sufficient to 

 permit the volume of water needed to enter under them. From 

 these main ditches innumerable distributing ditches radiate and 

 thus carry the life-giving water to the thirsty fields in the area 

 covered by the project. Water is usually turned into the ditches 

 early in April and shut off about October. 



If these main ditches are left unguarded, the young fish 

 appearing a month or more later are almost irresistibly drawn 

 into them by the strong current and in a very short period of 

 time the younger ones have been carried through the various 

 feeders to ultimately find an untimely fate on the fields. Should 

 the larger and stronger ones be enabled to keep out of the 

 smaller ditches which lead directly onto the cultivated fields, 

 their fate is merely postponed until the water is drawn off in the 

 fall, and they are left to die in the rapidly-drying ditches. We 

 have ocular evidence that many millions of young salmon and 

 trout have met such a fate. This has been a terrible drain on 

 the Pacific salmon runs, and while numerous attempts have been 



