CS/K ATOM RATIOS OF MARINE ORGANISMS OF DIFFERENT TROPHIC LEVELS IN JAPANESE COASTAL WATERS

Cs/K atom ratios were examined in Japanese coastal waters and biota. The Cs/K atom ratios in coastal waters, chlorophyta (3 species), rhodophyta (10 species), phaeophyta (4 species), invertebrates (7 species), teleosts (15 species) were 2.1, 2.1, 1.9, 4.6, 3.5, 12 (x 10(-7)), respectively. The Cs/K atom ratios were especially large in teleosts examined. Cs/K atom ratios in organisms increased with the elevation of the trophic levels of the organisms. An ''increase ratio'' of Cs/K ratio was approximately 1.62 per one step elevation of trophic level. The highest Cs/K atom ratios observed in teleosts suggested both the discrimination of Cs from K in teleosts and the discrimination of Cs from K in transferring these elements along food chains.