ACCUMULATION, REGULATION AND TOXICITY OF COPPER, ZINC, LEAD AND MERCURY IN HYALELLA-AZTECA

Zinc, lead and mercury accumulation in the amphipod Hyalella azteca in creases with increasing exposure to metals. During 10 week chronic tox icity tests, metal accumulated at the highest non-toxic/lowest toxic c oncentration was 126/136 mug Zn g-1, 7.1/16 mug Pb g-1 and 56/90 mug H g g-1 dry weight. Concentrations of lead and mercury in control animal s were substantially lower (1.3 mug Pb g-1 and 0.4 mug Hg g-1), but co ncentrations of zinc in controls (74 mug g-1) were about one half thos e of the lowest toxic concentration. Copper was completely regulated. Accumulated copper concentrations after 10 weeks exposure to all water borne copper concentrations resulting in less than 100% mortality were not significantly different from controls (79 mug g-1). Lead and merc ury concentrations in wild H. azteca should be useful indicators of po tential toxicity. Zinc accumulation may also be a useful indicator of zinc toxicity, but careful comparison with control or reference animal s is necessary because of the small differences between toxic and cont rol concentrations. Copper is not accumulated by H. azteca under chron ic exposure conditions and body burdens of field animals cannot be use d as an indicator of exposure or potential toxic effects. Short term e xposures to copper, however, result in elevated copper concentrations in H. azteca, even at concentrations below those causing chronic toxic ity. Short term bioaccumulation studies might, therefore, provide a us eful indication of potential chronic copper toxicity.