Influence of sediment in copper toxicity tests with the polychaete Neanthes arenaceodentata

Adult male Neanthes arenaceodentata were exposed to measured concentrations of 0.04, 0.06, 0.10, 0.16 and 0.26 mg l⁻¹ Cu in a continuous-flow bioassay system, with and without a clean sand, to assess the influence of sand on Cu induced mortality. The presence of sand did affect the results. The 28-day LC50 was lower for polychaetes exposed without sand than those with sand, 0.044 and 0.10 mg l⁻⁵ Cu, respectively. The reasons for this difference are discussed.