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inorganic elements. Samples for selenium analysis were collected monthly and those for ICP were collected bimonthly. Filtered and unfiltered water was collected for selenium analysis. Water was filtered through a 0.4 Jlm polycarbonate filter using a Geotech Filtration unit and 200 ml of filtered water samples was acidified with 2 ml of ultrapure HCI and stored frozen until analysis of selenium concentrations. Two-hundred ml of unfiltered water samples (but passed through a 25 Jlm filter bag) was acidified with 2 ml of ultrapure HCI and stored frozen until analysis of selenium concentrations. Samples for ICP analysis were filtered (0.4 Jlm) as described above and acidified with 2 ml of ultrapure HN03 and stored frozen. During the egg study, water samples were collected weekly from the pre filtered (25 Jlm filter bag) site waters for selenium analyses, and during the larval fish study for selenium and ICP analyses. The water was filtered (0.4 Jlm filter) and preserved as described above. Sediment samples were collected in May 1995, October 1995, and April 1996 from each site where the adult fish were held. Sediment was collected by a petit ponar grab sampler, placed in a large plastic pan, thoroughly mixed, and large pieces of debris removed (plants, twigs, rocks, etc.). Three subsamples of the homogenized sediment were collected in polyethylene bottles, and stored in a freezer until analysis. One sample was analyzed for selenium, and a second sample was analyzed for inorganic elements by ICP analysis. A second portion of each of the samples collected in October 1995 and April 1996 was analyzed for total and inorganic carbon, for total, volatile, and fixed solids, and a third portion was examined for sediment texture. Samples for carbon analysis were oven dried overnight at 1050C in a Fisher Isotemp oven. Dried samples were homogenized and ground in a CRC Micro-mill. Subsamples of about 30 mg each were wrapped in aluminum foil and bagged in Whirl-pak bags. The subsamples were sent to the Columbia Environmental Research Center (CERC), Columbia, MO, for analysis of . total anu inorganic carbon; organic carbon was determined by subtraction. Carbon analyses were accomplished with a Coulometrics Carbon model 5020 analyzer. Total, volatile, and fixed solids were determined by standard methods (APHA et al. 1995). Briefly, subsamples were weighed in an aluminum drying pan and air-dried prior to oven drying and muffle furnace ignition. Total solids was determined by drying the sediment overnight in a Fisher Isotemp oven at 1050e. Constant weights were determined by loss of less than 4% or 50 mg, whichever was less. Fixed and volatile solids were determined by ignition at 5500C for 60 minutes in a Thermolyne model FA1730 muffle furnace and then allowed to cool overnight in the furnace before weighing. Particle size determination of sediments was determined by standard methods (ASTM 1993). Samples were air-dried on fiberglass trays for 3-6 days, and large aggregates of dried sediment were crushed with a mortar and rubber-covered pestle. The dried sediment was sieved to remove particles >2.0 mm. Dried sediments were weighed, and stored at 40C until analysis. Each sample was analyzed in duplicate. Hydrometer analyses were conducted in l-L sedimentation cylinders or graduated cylinders using ASTM model 152H hydrometers following standard methods (ASTM 1990c). Briefly, sediment subsamples were dispersed overnight in 40 gIL sodium hexametaphosphate solution. A Hamilton Beach Scovill mechanical stirrer and a cup with baffles was utilized to further disperse the sample before hydrometer analysis. The results were plotted on graph paper and the percentage for the partic1e size of interest was interpolated from the graph. Particle sizes were classified according to the U.S. Geological Survey classification scheme, which is based on the Wentworth grade scale: sand 0.063 mm - 2.0 mm, silt 0.004 - 0.062 mm, and clay <0.004 mm (Guy 1969). 19 I I I I I I I I I I /1 I I I I I I I I