Effect of Oxygen Concentration on the Bioavailability of Copper for the Bivalve 'Macoma balthica'

摘要

Copper is a trace element in seawater and sediment, classified as heavy metal, and well known as essential micronutrient and necessary cofactor for many metabolic processes. Nevertheless, at elevated concentrations, mostly reached in areas where the anthropogenic impact is higher, it can become toxic. In an experimental set-up the bivalve Macoma balthica was exposed to copper under different oxygen conditions. Two special aquaria were used to see whether the uptake of metal by the bivalve was influenced by the oxygen concentration in water and sediment. Results showed that a reduced oxygen tension (3.2 to 4 mg/l) in the water increased the accumulation of copper and caused a synergistic lethal effect on animals exposed to high doses of metal (25 to 50 ppb). Condition as well as copper concentrations in the sediment changed only slightly or not, and showed no relation with copper accumulation in the animals.