摘要

Coastal pollution is complex, often consisting of multiple contaminants, and it is increasingly recognised that exposure to combinations of pollutants can produce different outcomes than each does separately. This study investigates the toxicity of three major pollutants in coastal environments (copper, lead and zinc) individually and in binary mixtures on larvae of Evechinus chloroticus, a sea urchin endemic to New Zealand. Larval development assays were conducted for 72 h. Median effective concentrations (EC50) for normal larval development for individual metals were 5.4 mu g/L Cu, 52.2 mu g/L Pb and 27.7 mu g/L Zn. Evechinus chloroticus was more sensitive to copper and zinc than most echinoid species tested to date. Effects of metal mixtures were analysed using a toxic unit (TU) approach. Cu + Zn and Cu + Pb had a less-than-additive effect on E. chloroticus larval development. By contrast, Zn + Pb was strictly additive. None of the interactions were strong, with sums of TU ranging from 1.00 to 1.85. These results support the use of criteria based on strictly-additive models to determine whether these three metals exceed water quality thresholds when occurring in a simple mixture.

  • 出版日期2017