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.'\ I "I b <':'1 N ~.~.. ;;'. parameters were higWy variable, as evidenced by the large coefficients of variation (mean/SO x 100) that ranged from 52 to 236%. The variation in these parameters was partly due to (0 differences in the amount of food added to the tanks and in daily cleaning efficiencies (siphoning .! '"'I and filtering). Any direct adverse effects of suspended solids on the fish were believed to be minimal because measured concentrations in the tanks (range 4-77 mg/L) were below concentrations considered to be a protective of salmonids against gill damage (80-100 mg/L, Wedemeyer 1996). For the larval exposures, all measured parameters, except for chloride, magnesium, and conductivity, were within 10% of measured values in the blending tanks (Table 1), The high cWoride, magnesium, and conductivity values, relative to those in blending tanks, were probably due to the high salt concentration of the brine shrimp solution fed to the larvae. Brine shrimp were hatched and cultured in reconstituted sea water at about 35 gIL salinity, prepared by dissolving Instant Ocean (Aquarium Systems, Mentor, OH) dehydrated sea salts in deionized water. Adult Exposure Mortality One male and eight females died while they were at our laboratory from December 16, 1996 to September 21, 1997 (Appendix B). However, there were no mortalities during the exposure phase of the study. The one male mortality occurred during the acclimation period, 16 days before the study began. All female mortalities occurred during or after the depuration phase of the study, Among the female mortalities, three were spawners and five were nonspawners, The mortality of the spawners was probably due to handling stress.associated with artificial fertilization, because all three females died within 6 days after being spawned. One of the 27