|Budget Amount *help
¥2,200,000 (Direct Cost : ¥2,200,000)
Fiscal Year 1999 : ¥500,000 (Direct Cost : ¥500,000)
Fiscal Year 1998 : ¥1,700,000 (Direct Cost : ¥1,700,000)
The aim of this work was to determine the normal levels of elements in marine invertebrates, and to test the usefulness of such organisms as a bio-indicator of environmental conditions. I determined 20 elements in soft tissues or organs of 23 species of marine invertebrates caught from the sea around Japan by photon activation analysis and neutron activation analysis mainly. The analyzed elements were ; Ag, As, Br, Ca, Co, Cr, Cu, Fe, I, Mg, Mn, Mo, Na, Ni, Pb, Rb, Se, Sn, Sr, and Zn. From the data obtained, I could obtain several characteristics about the levels of marine invertebrates.
● Concentrations of Mg and Rb were almost constant (10^3 -10^4, 1-10 μg/gDW) for all the organs and species determined.
● The levels of Ca, Fe, Mn, and Sr in the soft tissues of several trough shell caught from same area had large differences. And it was same for the levels of Ca, Cu, Fe, Mg, Mn, Na, Sr, and Zn of gonads of sea-urchiness. They might be the differences between sexes.
● The levels of Ni in mid-gut-gonads of ear shells from different areas showed large differences.
● Very high levels of As (ca.100 μ g/gDW) were obtained for gills, hepatopancreas, and muscles of spiny lobsters. It is supposed that high levels of As in spiny lobsters comes from sea weeds through shells or other foods. It might become clear by studying about the migration of As in food chain of spiny lobster.
● It is notable that the levels of Ag are relativelly high (ca.5 μ g/gDW) in mantles of scallop shells and rock oysters comparing to other species. There are few information about Ag in biological samples. Therefore it is worthy to determine the chemical form of Ag in biological samples to know the role of Ag.