27 



PorACABts of Adult Ratums 



The primary justification NMFS uses in the Federal Regieter dated 

 December 28, 1994, for changing status of Snake River fall chinoolc 

 salmon from threatened to endangered status are forecasts of abundance 

 in 1994 and 1995. Consequently it is prudent to evaluate how well prior 

 forecaatB of Snake River fall Chinook have performed. The following 

 provides such an evaluation: 



Projection of Natural Actual 



Escapement Over Escapement Over Differences 



Year Lower Granite Dam Lower Granite Dam Number Percent 



1993 457 742 +285 162% 



1994 299 441 -t-142 147% 



The forecast track record for Snake River fall Chinook is short in terms 

 of duration. Both projections significantly underestimated the actual 

 escapements past Lower Granite Dam. Use of projections that have so 

 significantly underestimated actual escapements as the basis for 

 changing the listing status of Snake River fall chinook is not 

 consistent with the Endangered Species Act requirement to use the best 

 available scientific and commercial data when making listing decisions. 



Hatchar7 Strays and Oenatic Integrity 



Coded wire tag technology was developed during the late 19708. This 

 technology has provided fishery scientists with a tool to identify 

 origins of returning anadromous salmonids. Releases of hatchery spawned 

 Chinook at various Columbia Basin facilities were first coded wire 

 tagged during the late 1970b and returns of these fish during the early 

 1980s provided the first estimates of straying rates of these hatchery 

 spawned fish. 



Adult Snake River strays in the escapement past Lower Granite Dam were 

 first documented in 1983 and straying of Snake River hatchery fish past 

 this dam have occurred each year since then (Tables 3 and 4 and Figures 

 4 and 5). Snake River hatchery strays were estimated to represent more 

 than 10% of the total escapement past Lower Granite Dam during 10 of the 

 11 years between 1983 and 1993 (Table 4) and these fish were estimated 

 to represent more than half of the total escapement during the years 

 1987 (67%) and 1990 (52%). 



Adult Columbia River strays in the escapement past Lower Granite Dam 

 were first documented in 1984 and straying of Columbia River hatchery 

 fish past this dam have occurred each year since then (Tables 3 and 4 

 and Figures 4 and 5). Most of the Columbia River strays were from 

 juvenile fall chinook salmon stocked in the Umatilla River, although 

 hatchery fish from other Columbia River system hatcheries have also 

 strayed past Lower Granite Dam and entered the Snake River spawning 

 grounds. Columbia River hatchery strays were estimated to represent 

 more than 10% of the total escapement past Lower Granite Dam during 4 of 

 the 10 years between 1984 and 1993 (Table 4) and these fish were 

 estimated to represent more than 20% of the total escapement during the 

 years 1989 and 1990. 



The potential affect of such high hatchery stray rates on the Snake 

 River spawning grounds, both from Snake River hatcheries and from 

 Columbia River hatcheries was an issue of concern when Snake River fall 

 Chinook were first listed under the Endangered Species Act as a 

 threatened species. Additionally, contamination by Columbia River 

 hatchery fish of the brood stock used at Lyons Ferry Hatchery was a 

 concern at the time Snake River fall chinook were listed. Waples et al. 

 (1991) cited the proportion of Columbia River hatchery strays entering 

 the brood stock at Lyons Ferry Hatchery as 4%, 18%, 39%, and 25% in 

 1987, 1988, 1989, and 1990; respectively. 



In 1990, a genetic control program was implemented. "Mining" for Lyons 

 Ferry Hatchery brood stock at Ice Harbor Dam and at Lower Granite Dam 

 was confined to fish with coded wire tags (hatchery spawned fish). 

 Before gametes of these fish were mixed with other gametes, their tags 



