The Absorption of Zinc and Other Metals by the Brown Seaweed Laminaria Digitata

Abstract

The absorption of zinc has been studied in the brown seaweed Laminaria digitata (Huds.) Lamour., with use of the radionuclide ⁶⁵Zn and atomic absorption analysis. No evidence of the regulation of zinc by the plant has been found. Absorption of zinc or ⁶⁵Zn is a gradual process of accumulation which may continue throughout the life of the plant and is not accompanied by the exchange of zinc. As a result, once it has been absorbed, zinc or ⁶⁵Zn shows little tendency to be lost from the plant. The amounts of zinc or ⁶⁵Zn which can be accumulated from sea water containing different concentrations of zinc and the effects on these of growth, light and competition from other metals have been studied. Possible sites at which zinc might be bound have been discussed, and the experimental results have been compared with the situation found in the field.