CONCENTRATION AND DISTRIBUTION OF COPPER AND CADMIUM IN WATER, SEDIMENTS, DETRITUS, PLANTS AND ANIMALS IN A HARDWATER LOWLAND RIVER

The concentration and distribution of copper (Cu) and cadmium (Cd) wer e examined in water, sediments, detritus, plants and animals in a smal l, lowland, hardwater river. Consistently higher concentrations of Cu and Cd were found in all types of samples from two sites. There were m arked variations in metal concentrations between different types of sa mples, and between seasons. Copper and Cd were mainly concentrated in sediments, organic detritus and biota, while concentrations in water w ere three orders of magnitude lower than in the other components in th e system. The relatively high concentrations of Cu and Cd in biota sug gests that they provide an important pathway for metal transport throu gh the food web in this particular hardwater river. From the rank orde r of concentrations it appears that sticklebacks exert a greater degre e of control than invertebrates in the uptake and elimination of Cu an d Cd.