@inproceedings{oai:repo.qst.go.jp:00053376,
 author = {Fuma, Shoichi and Ishii, Nobuyoshi and Tanaka, Nobuyuki and Takeda, Hiroshi and Miyamoto, Kiriko and Yanagisawa, Kei and Kawabata, Zenichiro and 府馬 正一 and 石井 伸昌 and 田中 伸幸 and 武田 洋 and 宮本 霧子 and 柳澤 啓},
 book = {Proceedings of the International Symposium on Radioecology and Environmental Dosimetry},
 month = {Apr},
 note = {The purpose of this study was comparative evaluation of effects of ionizing radiation and other various toxic agents on aquatic microbial communities. For this purpose, the authors investigated effects of gamma-rays, ultraviolet (UV) radiation, acidification, aluminum, manganese, nickel, copper and gadolinium on the microcosm, i.e., the experimental model ecosystem consisting of populations of the flagellate alga Euglena gracilis as a producer, the ciliate protozoan Tetrahymena thermophila as a consumer and the bacterium Escherichia coli as a decomposer. 
Effects of toxic agents in the microcosm were not only direct effects but also community-level effects due to interactions among the constituting species or between organisms and toxic agents. 
In general, the degrees of effects observed in the microcosm could be categorized as follows: (1) no effects; (2) recognizable effects, i.e., decrease or increase in the cell densities of at least one species; (3) severe effects, i.e., extinction of one or two species; and (4) destructive effects, i.e., extinction of all species. These results were analyzed by the ecological effect index (EEI), in which differences in the cell densities between exposed and control microcosm were represented by the Euclidean distance function. A 50 % effect doses for the microcosm (EDM50), at which the EEI became 50 %, were evaluated to be 530 Gy for gamma-rays, 2100 J m-2 for UV, 4100 micro M for manganese, 45 micro M for nickel, 110 micro M for copper and 250 micro M for gadolinium.},
 pages = {45--52},
 publisher = {Institute for Environmental Sciences},
 title = {Ecological effects of ionizing radiation and other toxic agents on the aquatic microcosm},
 year = {2004}
}