THE INTERACTION OF SULFATE AND SELENATE (SE+6) EFFECTS ON BRINE SHRIMP, ARTEMIA SPP

Sulfate has been shown to be antagonistic to selenate toxicity in aqua tic organisms. Brine Shrimp, Artemia spp., flourish in evaporation pon ds of the San Joaquin Valley which have selenium concentrations betwee n 1 and 6,000 mu g/l. The salinity is dominated by Na2SO4 rather than NaCl in these ponds. Brine shrimp raised in artificial seawater at 25 degrees C exhibited a 96h LC50 of 0.006 mg/l selenate with sulfate lev els at 0.05 mg/l. The LC50 for those in waters containing 14,000 mg/l sulfate was 81.97 mg/l selenate. Developmental assay results indicated that selenate had no effect on emergence or hatching of brine shrimp regardless of the sulfate concentration. However, selenate was lethal to nauplier larvae. Mortality was significantly reduced with increased sulfate concentration in the media.