Determination of Trace Elements in Marine Organisms-I

Factors for Variation of Concentration of Trace Element

Abstract

As one part of our radioecological studies one the marine environment, the concentrations of stable isotopes such as Mn, Fe, Co, Ni, Cu, Zn, Rb and Cs in marine organisms were determined by atomic absorption spectroscopy and neutron activation analysis, and the environmental and biological factors controlling the concentrations of stable elements were examined.
Only small differences of concentration were observed among the species of marine fishes, but marine invertebrate and algae showed species specificity. For the iron family elements different concentration factors were obtained. Values in the muscles of marine fishes were in the range of 10³ for Fe, 9×10 for Co, and 10 for Ni. A regional variation was found for Cu and Zn, whose highest values were observed in the samples collected at the seashore of Mizuki in Ibaraki prefecture. The distribution of trace elements in each algal body was not homogeneous; for almost all trace elements the concentrations tended to increase with the distance from the growing tip. Trace elements for lamina in the organs of Sargassum showed the highest values, where Fe in particular was concentrated twenty times as much as in the receptacle. Little variation withe growth of marine algae was observed in the case of the trace elements other than Fe; the Fe concentration tended to decrease with growth. Seasonal variation was observed for Fe, Co, and Zn in Sargassum. These elements reached their highest values in March and thereafter decreased gradually, whereas Mn and alkali metals did not show any apparent seasonal variation.