n in the reservoirs. 



Dams without fish ladders block salmon migrations. 



The Long Struggle of 



[Columhm Bjver 

 mon 



From the time they are hatched to the time 

 they die, salmon are in motion — and in 

 peril. While still quite young, they drift on a 

 wash of runoff that carries them down from their 

 freshwater birthing streams to the saltwater sea. For 

 some young salmon, this first trip of their lives can 

 be 900 miles long. They must pass as many as nine 

 major hydroelectric dams, where turbines can kill or 

 stun them, leaving them easy prey for waiting preda-- 

 tors. 



Before the dams were built, the journey to the 

 sea was a quick one, lasting a week or less. With the ' 

 dams, the salmon are often stalled in reservoirs. The 

 hazard here is a biological one. Their instinct to mi- 

 grate can be lost. 



Only about a quarter of the young salmon sur- 

 vive the first leg in their long migration. 



Once in the Pacific Ocean, most of the 

 Columbia' s salmon swim north, traveling thousands 

 of miles, feeding on small sea creatures along the 

 way. Larger sea creatures, in turn, feed on them. 



In the ocean, Columbia River salmon also are the 

 target of major commercial and sport fishing indus- 

 tries. By the time they turn back toward the mouth 

 of the Columbia, only a fraction of their original 

 number remain. 



In the lowest reaches of the Columbia, fishers 

 again await the salmon. Fish that escape capture 

 here are the remnant hope of future runs, but they 

 must first struggle back past the dams. 



The final survivors — typically less than 1 per- 

 cent of the original tiny migrants — seek the stream 

 of their origin, where they will reproduce, then die. 

 But more than a third of the spawning streams in the 

 basin have been blocked off by dams that lack fish 

 ladders. Much of the remaining habitat was degraded 

 by siltation, pollution, excessive water temperature 

 and the loss of spawning gravel and deep holes 

 where salmon rest and feed. The poor condition of 

 these streams will be the first, and last, constraint on 

 the survival of tjie Columbia River salmon. 



Note: The pointers used here are graphic devices. 

 These impacts occur throughout the basin. 



15 



