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life wildlife tableaus with no more effect on the animals than they would have 

 had at a Disney nature movie. A tour boat hovered a few feet from a large 

 bobcat stalking a feeding deer. The doe, spotting the creeping predator, 

 charged, striking with her sharp hooves, nearly killing th^ fleeing cat before it 

 could scramble under a boulder to safety. Both animals seemed oblivious to the 

 boat or its 20 or so entranced passengers. 



In 1995 power boat passengers observed bear, bobcats, mountain lion, 

 moose, deer, elk, big horn sheep, mountain goat, bald eagles, osprey, golden 

 eagles and other less spectacular creatures with little or no effect upon them. 



Commonly accepted wisdom would tell us that motorized boats would be 

 more upsetting to wildlife than nonmotorized craft. Experiences on the river 

 don't seem to support that theory, however. Wild birds and animals appear to 

 have learned that power boats don't hunt them or take their lives and pay little 

 attention to boats or passengers. Float craft, on the other hand, slip up on wild 

 creatures quietly, more closely emulating the behavior of their predators. Little 

 is available in the way of studies, but thousands of wildlife observations by 

 power boaters in Hells Canyon would seem to belie the oft accepted truths. 

 Salmon 



The only comprehensive study of jet boat impacts on salmon was conducted 

 by the University of Alaska, Fairbanks (Reynods and Horton, Effects of Jet 

 Boats on Salmonid Reproduction in Alaskan Streams, 1994). An earlier study 

 in New Zealand suffered some serious flaws, prompting the new research. 

 There are, of course, many differences between the Alaskan salmon and streams 

 studied and our salmon and river in Hells Canyon. The research dealt with 

 sockeye salmon in very shallow water of small streams with fine substrates. In 

 Hells Canyon the only salmon species that spawn in the river are Fall Chinook, 

 They arrive in the fall, after the primary boating season; the Snake's waters are 

 deep and its gravels large. 



The Alaska study indicated that slow moving humans, shadows and bears 

 wading the stream were more disturbing to spawning adult salmon than jet 

 boats. A study of another fish species was cited which showed that slower, 

 nonmotorized boats produced a greater disturbance to spawning behavior than 

 fast, motorized craft. While salmon flared away from their shallow spawning 

 beds in response to a jet boat pass, they returned in a few seconds to a minute to 

 resume their activity; in response to humans and bears they moved away 

 considerable distances for several minutes. 



The researchers found that in small, shallow, steams with fine gravels, 

 intense use by large jet boats can kill incubating salmonid embryos. Many 

 variables affected mortality and water depth thresholds couldn't be clearly 

 defined, although the highest mortality occurred at depths of 13 to 23 



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