NAA has been applied to determine the concentration of K, As, Se, Zn, Cr, Cs, Fe, Co, Sb, Ni and Ca in sediments and a macroalgae
species collected from the Küçükçekmece Lagoon and Marmara Sea. The lagoon sediment showed higher metal levels than the sea
sediment. The metal contents in algae species are not changed significantly between months and sampling sites except Zn and
Cr. The profile of the lagoon sediments was also investigated.