p. 175 - 187 NEUTRON ACTIVATION ANALYSIS OF SOME MARINE MACROPHYTES ALONG THE ROMANIAN BLACK SEA SHORE A. S. Bologa 1), Ana Pantelica 2) and Maria Salagean 2) 1) Romanian Marine Research Institute Constanta 2) Institute of Physics and Nuclear Engineering Magurele Bucuresti Abstract The concentration of 23 elements contained in 11 species of marine algae and phanerogams collected along the Romanian Black Sea coast have been determined. A comparison with earlier chemical determinations of Na, K, Ca and Mg concentrations is breafly presented.