Dissimilarity of 60Co/Co, 137Cs/Cs and 90Sr/Sr ratios in Beryx splendens from the Pacific and Atlantic Ocean

Specific radioactivities (SR) of 60Co/59Co, 137Cs/133Cs, 90Sr/86-8Sr, the elemental abundance of K, Rb, Fe, Zn, Ag and 14 others were determined on Beryx splendens collected from the southwest coast of the Africa on the Atlantic and at the Emperor Seamounts (E-smt) on the Western North Pacific. An overall ratio of 137Cs, 90Sr and their SR was 1 : 1/4 : 1/8 in Beryx from Kinmei (K-smt) of E-smt, Valdivian smt (V-smt) on Walvis Ridge and A-smt on Guinea Rise. Muscle content of 137Cs was the highest: 0.85 Bq/kg wet weight in K-smt Beryx and the lowest: 0.12 Bq in A-smt Beryx; this reflects well 137Cs content in seawater. By the concentration factor 1.48 x 102 (133Cs muscle/133Cs seawater) and 137Cs muscle, content of 137Cs in Beryx habitat was estimated at 6 - 7 mBq/l for K-smt, 1.5 - 2.0 mBq for V-smt and 0.7 - 1.0 mBq for A-smt. The strong differences were, first attributed to the different fallout by latitudes. 60Co ranging 30 - 150 mBq/kg wet weight was detected in livers of Beryx and a similar level of 60Co was found in the pectoral dark muscle of Beryx exclusively from the Pacific specimens (K-smt, Sagami Bay, Shichito-Iojima Ridge, Nansei-shoto Ridge, Kyushu-Palau Ridge). Coefficient of variation (CV) of radionuclides and their SR were in 60 - 100 % among A-V-K-smt Beryx. However, CV ranging within 10 - 34 % in the Pacific 6 groups. In most cases CV of many elements by each part lay less than 45 % through the three localities, except Ag and Cl. Thus, the benthopelagic Beryx splendens may serve as an indicator reflecting environmental radioactivities in 200 - 600 m depth of the Oceans. (author)