TOXICITY OF CADMIUM, HEXAVALENT CHROMIUM AND COPPER TO MARINE FISH LARVAE (CYPRINODON-VARIEGATUS) AND COPEPODS (TISBE BATTAGLIAI)

For comparative purposes, the toxicity of cadmium, hexavalent chromium and copper to marine fish larvae (Cyprinodon variegatus) and copepods (Tisbe battagliai) has been evaluated. Toxicity to fish larvae was measured in terms of survival and growth over 7 days, whilst toxicity to copepods was assessed in tel ms of survival and reproduction after 8 days exposure. For fish larvae, 96 h LC(50) values (based on mean measured concentrations of total metal ion) were 1.23 mg Cd/litre, 31.6 mg Cr6+/litre and >0.22 mg Cu/litre. Subchronic values (SChVs) for larval fish survival and growth after 7 days were 0.75 mg Cd/litre, 24.0 mg Cr6+/litre and 0.16 mg Cu/litre. For copepod nauplii and adults, 96 h LC(50) values were as follows. 0.46 mg Cd/litre and 0.34 mg Cd/litre, respectively, 1.60 Cr6+/litre, and 5.9 mg Cr6+/litre respectively; and 0.064 mg Cu/litre and 0.088 mg Cu/litre, respectively. SChVs foR naupliar survival and adult survival or reproduction after 8 days were 0.024 mg Cd/litre, 0.42 mg Cr6+/litre and 0.008 mg Cu/litre.