Affiliation: | 1.Fukushima Prefectural Inland Water Fisheries Experimental Station, Inawashiro, Fukushima, 969-3283, Japan ;2.Institute of Environmental Radioactivity, Fukushima University, Fukushima, 960-1296, Japan ;3.The Institute of Statistical Mathematics, Tachikawa, Tokyo, 190-8562, Japan ; |