Strontium-90 and cesium-137 in sea fish (from Aug. 1983 to Dec. 1983)

Sr-90 and Cs-137 in sea fish were determined using radiochemical analysis. Thirteen species of fish (Hexagrammos otakii, Trachurus trachurus, Sardinops melanosticta, Sebastiscus marmoratus, Limanda herzensteini, Spratelloides gracilis, Oncorhynchus keta, Scomber japonicus, Chrysophrys major, Arctoscopus japonicus, Seriola quinqueradiata, Mugil cephalus, and Decapterus muroadsi) were collected during the fishing season from 22 sampling locations. Only the edible part was used in cases of larger sized fish, and the whole part was used in cases of smaller ones. Each sample was weighed and placed in a stainless steel pan or a porcelain dish. After carbonized, the sample was ashed in an electric muffle furnace. The maximum value of Sr-90 was 1.9 +- 0.34 pCi/kg in Mugil cephalus collected from Okayama in November 1983; and that of Cs-137 was 9.0 +- 0.46 pCi/kg in Seriola quinqueradiata collected from Ishikawa in October 1983. (Namekawa, K.)