19 



Probability of Paraittenc* with R«Bp«ct to SuryiTkl 



An objectiva analysis of tha currant status of Snaka Rivar fall chinook 

 should also consider tha naw information recently developed in 

 conjunction with the IDFG v NMFS litigation settlamant negotiations 

 relative to the probability of persistence with respect to survival 

 under recent and various alternative hydro system management 

 configurations. The key question here is whether changes in the 

 management of the hydro eyatem are placing the stock of fall Chinook in 

 more jeopardy (indicating a change in status may be warranted) or are 

 placing the stock in less jeopardy (indicating a change in status is not 

 warranted) . 



Spawnar-Racrult Relationship 



An objective analysis should include investigation of tha effects of 

 spawner density on recruitment of Snake River fall Chinook. A spawner- 

 recruit relationship developed for escapements past Lower Granite Dam is 

 needed to assist in quantifying the level of escapement appropriate for 

 this stock under present conditions. Prior analyses have concluded that 

 escapements should increase above recent levels, but an objective 

 analysis is generally lacking relative to how much increase is 

 appropriate given the diminished availability of habitat for Snake River 

 fall Chinook since 1975. 



This spawner-recruit relationship should be limited to escapements 

 enumerated since 1975 since the progeny of these escapements had to 

 negotiate all four of the lower river dams and these spawnera and their 

 recruits had to reside in the reduced freshwater spawning and rearing 

 hcOsitats available following construction of all major Snake River dans. 

 This relationship (a Ricker function) has the potential to be far more 

 informative than the spawner to spawner relationship developed by Dygert 

 (1994) and Roler (1994) because it will help to determine if production 

 of fall Chinook is dependent upon spawner density as is typically the 

 case for anadrocnous salmon populations. Further residuals in the 

 modeled spawner-recruit relationship can be used in conjunction with 

 other variables to better understand the factors currently limiting 

 production of Snake River fall Chinook spawning and rearing in the wild. 



Forecasts of Adult Returns 



An objective analysis should include evaluation of the accuracy of 

 forecasts to predict future years returns of Snake River fall chinook 

 before these forecasts are uaed to make listing status changes and 

 before too much faith is placed in these forecasts for other ESA related 

 management actions. 



Hatchery Strays and Genetic Integrity 



An objective analysis of the current status of this ESA protected stock 

 should also address the "species" question. In determining if Snake 

 River fall chinook qualify as a species under the ESA, Waples et al. 

 (1991) concluded with the following statement 



Although Che NNFS Horchuest Region Biological Review Team (BRT) 

 concluded that, historically. Snake River fall chinook salmon were 

 an ESCI , it is not so clear whether this is still the case. One 

 viewpoint is that introgreasion from Columbia River hatchery 

 strays has caused the Snake River population to lose the qualities 

 that made it 'distinct' for ESA purposes . Evidence in support of 

 this viewpoint includes genetic and tagging data documenting 

 effects of straying on Lyons Ferry Hatchery brood stock, estimates 

 that in 1990 a high proportion of fish passing Lower Granite Dam 

 and found on nearby spawning grounds were hatchery strays, and the 

 lack of any positive information documenting the continued 

 existence of 'pure' wild fish. However, given that 1) an EStJ was 

 present until at least the early 1980s, f) substantial straying of 

 upper Columbia River hatchery fish has occurred only within the 

 last generation , and 3) no direct evidence exists for genetic 



