ALP 3

Contents
Sleeve Valve Passage Survival Testing
To test sleeve valve passage survival, we injected nonnative game fish, forage fish, and fish
embryos into the outlet discharge pipe at increasing reservoir depths and pressures at or near
each additional increment of atmospheric pressure (atm). Sleeve valve passage survival testing
began soon after the reservoir filled above its sill level where water could be gravity fed into the
discharge pipe. Initial testing using live specimens during summer of 2009 were intended to
develop site - specific fish and fish embryo handling, injection, andretrieval methods and
occurred when the reservoir was below its minimum pool elevAhon of 6801 ft.
Other previous dam passage experiments using a variety, f speoiies, have shown that typical
pressure levels associated with the various subsystems othydraulic "powerplants do not induce
complete fish mortality, providing that the fish have the opportunity to',gradually acclimate to
these pressure levels (Foye and Scott 1965). ishowever, does not hold:faT higher rates of
pressure change and especially for decompression., Depending on how the svufm bladder of fish
exchanges air with the environment, fish species ca` be classified into two broad categories; 1)
physoclistous species like perch, bass, and sunfishes, rich have a closed air bladder that
changes its air content through diff:isl6 tto.the blood syAftof the fish, and 2) physostomous
fishlike salmon, catfish, and suckers, vsFhich t4vq a pneumatic duct connecting the air bladder
with the environment usually located thiU then th cavity. ,,There is a great difference of the
response speed of thesetwo- systems to pressure variations. Physosttatmous fish react in seconds
whereas; physoclistctts ash may -take a few 'hours (Lagler et al., ;1962). Therefore, physoclistous
fish are much more susceptible 0,mortality bec' of rapid pressure variations than
physostomous fish (Ve*Wos and'Siptiropoulos 1999).
Ylihaitgh ffcient foa eruilibr&I*,, buoyahey pt a constant depth, gas bladders offer
seven'&iadvantage +dr rapid ehanges in depth such as those that occur when fish are drawn or
swim.,j&o deep turbine intakes from - Surface waters. Swim bladders expand when fish swim
towards ;surface, where -t"7te,,pressure is less, and are compressed when they swim deeper. In
accord with.- #gyle's Law (for the volume afgases under pressure), a swim bladder volume
should change. o,ne -half for every one atmosphere of pressure change. Thus, the density of a
fish with a swim Bladder matchekthat of the water (hydrostatic equilibrium) only at one depth
(the plane of equihbrits a), un *S the quantity of the gas in the bladder is adjusted' (Coutant and
Whitney, 2000).
After Lake Nighthorse overtopped its sill level, water could be discharged by gravity thus, not
requiring additional pumping to fill the discharge pipe. The reservoir's sill level is at 6761 ft and
preliminary testing started at 6775 ft during June 2009, where the depth of the reservoir was 45 ft
and the depth to the centerline of the sleeve valve was 63 ft with a pressure of approximately 3.1
atm. Subsequent sleeve valve passage survival testing occurred at or near each additional atm
increase along with tests near minimum pool and at the end of the 2010 water year (Table 1). At
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