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<br />health, and muscle plugs were taken for selenium analysis. Two fish from each group held at the
<br />three exposure sites were sacrificed after spawning, after 30 days, and after 60 days in the
<br />depuration phase of the study for analysis of selenium concentrations in various tissues. The
<br />following samples were taken from each fish: muscle tissue from the dorsal area close to where
<br />muscle plugs were removed, liver, kidney, gonad, gall bladder, and gut contents (only two fish).
<br />The samples were placed in Whirl-Pak bags and stored frozen at -200C until chemical analysis.
<br />
<br />Informal observations of adult razorback sucker
<br />
<br />Five adult male razorback sucker used in an electroshocking study (Muth and Ruppert
<br />1996) were held at North Pond in a hoop net for 89 days (March 5 - June 2, 1995). The purpose
<br />of the informal observation was to determine if adult razorback sucker could survive in North
<br />Pond with selenium concentrations in water as high as 170 /lgIL. This test was conducted prior
<br />to stocking the young adults in the reproduction study. Fish had limited access to bottom
<br />sediments and received a commercial fish diet (Silvercup, Nelson & Sons, Murray, UT)
<br />approximately every 7-10 days. Duplicate samples of the commercial fish food diet were
<br />collected for analysis of selenium concentrations. At 0,30,60, and 89 days of exposure, fish had
<br />muscle plugs collected as described previously. After 89 days of exposure, fish were sacrificed
<br />and stored frozen until selenium analysis of various tissues. The following samples were taken
<br />from each fish: muscle tissue from the dorsal area close to where muscle plugs were removed,
<br />liver, kidney, gonad, and gall bladder (no gut contents were available). The samples were placed
<br />in Whirl-Pak bags and stored frozen at -20oC until analysis of selenium concentrations.
<br />
<br />Water and sediment sampling
<br />
<br />Beginning in mid-April 1995, selected water quality characteristics were measured every
<br />week in situ at most of the 17 sample stations at the three test sites (Figures 3, 4, 5). In addition,
<br />water samples were collected at 17 stations every 30 days and analyzed for general water quality
<br />characteristics in the mobile laboratory. Water quality characteristics measured in situ at each
<br />site included pH, conductivity, salinity, air temperature, water temperature, and dissolved
<br />oxygen. Water quality measurements in water samples measured in the mobile laboratory
<br />included pH, conductivity, hardness, calcium, magnesium, alkalinity, and chloride. Two
<br />subsamples of each sample taken to the mobile laboratory were collected in polyethylene bottles.
<br />One sample was used for alnmonia analysis and was acidified to a pH <2 with concentrated
<br />sulfuric acid. The other sample was used for analysis of nitrate, nitrite, sulfate, total suspended
<br />solids, volatile solids, and fixed solids and was stored in a refrigerator at 40C. These subsamples
<br />were then shipped in a cooler with ice packs by overnight express to Yankton Field Research
<br />Station (FRS), SD, for analysis. All water quality characteristics were measured according to
<br />standard methods (APHA et al. 1995), except for the nitrogenous chemicals and chloride.
<br />Ammonia, nitrate, and nitrite were measured using ion-selective electrodes and following the
<br />procedures for low concentration measurements of the electrode manufacturer (Orion Research
<br />1990, 1991; AT! Orion 1994). Chloride was measured by a modification of the APHA et al.
<br />(1995) method (Hach Company 1992).
<br />Subsamples of water collected between May 1995 and June 1996 for water quality
<br />analyses from the 17 sample stations were taken for selenium analysis and ICP analysis of
<br />
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