89 



In the case of the Imnalia wild summer chinook, the Jiighcst surviva) occurred at a spill level of only 

 117 kcft while the third highest suivival occurred ai a spill le\el of only 8 2 kefs. The second highest 

 survival occurred at a spill levels of 54.8 kefs. Clearly, the data of Figure 1 show little consistency and 

 there is no dofinabie relationship between spill and the survival indices for the two populations of 

 Snake River chinook. 



A similar efTevl is found in data for the survival of fkll chinook migrants ft-om the Priest Rapids i 

 Hatchery fo; the period 1 980 through 1 987. Figure 2 shows a plot of migrant survival versus spill 

 flow 11 is apparent that some of the highest suivivais occur at spill levels of about 20 kefs and again at 

 spill leve's of about 160 kefs This constitutes a factor of 8 in the difference In spill rates. Based on 

 this large difference, along with the other data of the figuic, it is apparent that there is again no 

 consistency or definable relationship between spill and survival of this population of chinook salmon. 

 In su'.nmary, the available data on the survival of Snake River and mid-Columbia fisli stocks are Wghly 

 variable and fail to validate that spill is the best mechanism for fish passage at dams. 



A 1 additional coricern regarding the validation cf spill at; an optimum means offish passage is thai the 

 eiVecis of DOS and gas bubble trauma (GET) in fish, which arc the primary deleterious effects of spill, 

 have not been quantified in a manner which will allow a comparative analysis of the various fish 

 passage mechanisms. Without such a comparison, it is impossible to scientifically establish which 

 mecha;iism (or combination of mechanisms) will produce the greatest overall survival of salmonids. 



Furthermore, the NMFS 1 995 Rinlogical Opinion ignores much of the data from the literature, 

 especially those data which show adverse effects of DGS on fish The Biological Opinion often refers 

 to the risk analysis described in Spill cuxd 199^ RIskMamigemeni, which was prepared by the state 

 and tribal agencies However, the analysis methods contaimd in this latter document have been 

 criticized by NMFS' own staff, the Oregon Department of Er.vironmental Quality, and 8e\"eral 

 independent scientists The fiaws identified in this document a.-e such that the analysis and conclusicns 

 are invalid. 



The only justification which NMFS uses for seeking a variance to the stale water quality guidelines for 

 DGS (in order to permit high spill levels) is contained in the following statement taken from the 19y1 

 Biological Opinion 



"NMFS concluded that it was appropriate to seek an operation that would result in the EPA 

 criteria of I ]0% being exceeded primarily because of 1) the ability offish in a river environment 

 to compensate hydrostatically for the effects of dissolved gas supersaturation. and 2, the daily 

 fiucluaiion in levels of dissolved gas throughout most of the river." 



The statement with regard to fish having the "ability to compensate hydrostatically" is not 

 consistent with the scientific literature, which shows thai in many cases where fish have adequate 

 depth to compensate for DGS, they do not do so, and die of GBT as a result. NMFS' own 1995 net 

 pen studies (Vom below Ice Harbor Dam illustrate this point directly The high levels of mortality 

 which occurred In early May should have been avoided if the fish had compensated hydrostatically for 

 the effects of DGS Based on the measured TGP levels of 128%, a compensation depth of about 1.0 

 meter would have prevented bubble formation in the vascular systems of these fish (t^idler and Miller 



