91 



Smith (1974), using varied mysh gill nets on adjustable frames, has shown that up to 18% of Chinook 

 salmon jmolts and 7 9% of the sieelhend smelts can be found in the upper meter of the water column 

 upstream from Lower Monumental Dam on the Snake River Rondorf (1995), using hvdroacoustic 

 methodi, has shown that the dcptii distribution offish in Lower Granite Reservoir is quite variable. 

 Although the hydrcicoustic methods cannot sample accurately in the upper mctei of the water 

 column, Rondorfs data indicate that m some sections of the reservoir up to appioximatcly 18% of the 

 fish observed are in the 1 - 2 meter depths. Thus, the combination offish distribution depths and time 

 to mortality data from field and laboratoiy experiments indicate there is high risk of direct mortality to 

 fish exposed \o dissolved gas levels above 1 1 S%, l.inle is known about the level of indirect monaiity 

 {i.e., predatijn, disease, failure to adapt to sea water, eic.) associated with the sub-lethal effects of 

 GBT (NMTS 1994 Expert Panels on DGS «nd GBT). 



L'nforluriafeiy, the 1995 biological monitoring program, as designed, will not yield an accurate 

 assessment of the lethal or sublethal mortalities associated with the high levels of DGS present in the 

 Columbia and Snake Rivers The dlfTiculiy with the 1995 program is that it has not been designed 

 with an understanding of how fish are disliibutod in the Columbia and Snake Rivers in relation to 

 dis-.olved gas levels, periods of exposure, and poteniia! for mortality The NMFS 1994 Expert Panels 

 o:i DGS and GBT made recommendations regarding the design of a biological monitoring program for 

 ■i995. Few of the recommendations were implemented and the panel was never consulted regarding 

 the design of the 1995 monitoring program A team of scientists which reviewed the 1994 biological 

 monitoring program also made recommendation", for improving the design of the 1995 monitoring 

 program (Montgomery Watson 1994) Again, few of these recommendations were implemented in 

 1995 



At present, the 1995 biological monitoring program is an unfocused collection of attempts by various 

 agencies to sample fish without an understanding of the appropriate locations and conditions under 

 which to assess the impacts of DGS on the Columbia and Snake River juvenile and adult salmonids 

 In many cases, the examination methods are inferior to those used in 1994. For example, in 1994, 

 hatchery steelhead smolts were examined for bubbles in gill lamella and lateral lines using 90 - 100 

 power microscopes. In May of 1994, signs of bubbles in t;ill lamella were present in up to 60% of the 

 fish examined This led to a termination of spill in 1 994 Ii. ] 995, examination was done with 1 

 power microscopes and no signs of GBT are being reported even though TGP levels arc 10% to 1 5% 

 higher than in 1994 Cle-arly, there is a credibilhy problem in ihe results of the 1995 monitoring 

 progtam 



In 1994, both the NMTS Expert Panels on DGS and GBT and the Montgomery Watson scientific 

 review team pointed out the problem of high hydrostatic pressures i.i the smoll bypass systems 

 reducing or eliminating the signs of GBT in fish before ;hcy are intertepted for monitoring. Even with 

 the experimental results obtained /yom the Battelle Pacific Northwest Lnbo; atones experiments, the 

 smolt bypass system sites coniimio to be the primary locations used in monitoring for signs of GBT. 



Another problem with the monitoring program is that many of the agencies which have been most 

 vocal in their asserJon that high levels of DGS will not cause significant mortality In Columbia and 

 Snake Rjver salmonids are, in many cases, the people responsible for much of tht biological 

 monitoring. This presents a conflict of interest situation in that the credibility of tl)ese agencies may be 



