p. 357 - 364 DONNEES PRELIMINAIRES CONCERNANT LES PREMIERS EXERCICES RADIOMETRIQUES D'INTERCALIBRATION DE L'INSTITUT ROUMAIN DE RECHERCHES MARINES DE CONSTANTA DANS LA MER NOIRE V. Patrascu Institute Roumain de Recherches Marines Constanta Abstract This paper presents a synthesis and a way of interpreting the RMRI results on gamma measurements occasioned by the 38th cruise of the Ukrainean research vessel "Profesor Vodyanitsky" and a working stage at IBSS - Sevastopol. The vertical gradients in Cs-137 distribution in water and bottom sediments are underlined. At the Dniepr mouths, the Cs-137 value exceeds at least twice that at the Danube mouths (240 Bq/kg dry). The radionuclide K-40 has usual values in water and sediments. RMRI and IBSS have started bilateral intercalibrations. For the international intercalibration (USA, Ukraine, Romania) on samples from the Black Sea, a conclusions is to be reached soon. Key words: marine radioecology, Black Sea, Chernobyl