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Steae &'30/96 Pag© 3 



Rgure 1 iliustraiBa the survivals thai the Team caJcuteted using NMFS 

 assumed survival estfmatss tor eacii r9««rvo(r b^km Lower Granfte and tof a« 

 passage rotrtes throoflh eedn dam. Those survivai calculations are t>as^ on the 

 peroenftaoe of (ls^ that pass each cSam by the thre« alternate pessage routes. 

 During sp«<l. at a dam with a bypass system, th« fish vwH either go ovor the 

 spillway, into th© turt>4r>e8 or b& captured in the Dypasa system forcoltectton and 

 transport or in some cases returned to the river. Figure 1 illustratBS the in-river 

 survival conditions with and vwithout spiil al arfl projects. The irvriver survivals 

 without adcStional spill are 37 percent to below Bonnevitte and wfth sp«ll at aJI 

 projects as recommonded by NMFS the in-rivef survivais increase to 40 percent. 

 This is a very srrtafl increase tnat protoaWy cannot be rr»eesured arxl sgain 

 assurrtes nst increase in rrtonaJty caused by increased dissolved sas. 



Rgurts 1 aiso illustrates the projected survtvaJ of fish to b^ow Bonnevitie 

 taking into account the fish that are colioct«d and transportBd. The currerrt 

 tran^xjrtation system when combired wiih fish omi^rHting In the river wiM result 

 in approx*ma2aiy 78 percent of the fish that approach Lower Granite surviviog to 

 below Bonr>eville. Under the NMFS proposed spill program this survival is 

 reduced to 74 percert because fewer fish am coiJoctod for transport and 

 the*efOfe more fish are exposed to tt^ ojmuiative mortality of emigr38f>g past 

 eight darns and reservoirs. Again, ttie drfference between tftese survfvai 

 estBTiaisi is prnbably too smai) to measure but the generai lev^ of survival 

 under the proposed sptli program is likely to reduce survivais of listed salmon to 

 beiow Bonnevifie dam. 



The Team believes that spil is not a vi^rie downstrsarn passage soMion. 

 The current spiH program w* result in suc*t a sma^ change in survivals that it will 

 be impossible to measure while at the same tfme presenting substantiai sunrivai 

 risks due to gas bubb^ disease. WVale the Cofps of Engineers (Corps) and 

 fiMFS are doing thstr best to manage diasoived gas levels, it is stppanm th«t 

 technical and manAgemem failures have led to gas supersalLirceJon that exceeds 

 theNMFSetandaidsot 115%torabayand I20%taiirace. The result is that ws 

 do net have the abJBty to corttroi gas concentratioas to prect&ofy set levefa and 

 the impacts of qsb bubble ^se^M could exceed ttie possible Der^efrts of avoKjing 

 turbine mortaity. Our analysis has shown that the ngducttors In mortality in 

 passing dams «(th ss>* are nxafe then offset by the trxyeased risk of 

 super«rtUJ3lion snd 9t9 cumulaave mortaity erf pesaing nxilt^jie ressrwoirg and 

 dams. 



