The effects of salinity, temperature and sediment on the toxicity of copper to juvenile Hediste (Nereis) diversicolor (O. F. Muller)

Without sediment, increasing salinity (7.3 to 29.2‰) and increasing temperature (12 to 22 °C) reduced the toxicity of copper to juvenile Hediste diversicolor. The LC50 values ranged from 357 μgL(-1) in 7.3‰ to 513 μg L(-1) in 29.2‰ at 12°C and from 247 to 500 μg L(-1) at 22°C. In deionized water all the juvenile were dead in all solutions to which copper was added (100 to 600 μg L(-1)). Dead worms were swollen and everted their pharynxs. In higher doses of copper (500 to 600 μg L(-1)) the worms were abnormal in behaviour in all salinities (0 to 29.2‰). The ability to swim or crawl was disturbed.With sediments increasing temperature and increasing salinity increased the toxicity of copper to the worms. The LC50 values ranged from 3200 to 4100 μg L(-1) at 22°C. The response of the juvenile to copper was antagonistic to increasing temperature and salinity and synergistic to increasing salinity and increasing temperature without and with the sediment respectively.