title: Effects of acute gamma-irradiation on the aquatic microbial microcosm in comparison with chemicals.
abstract: Effects of acute gamma-irradiation were investigated in the aquatic microcosm consisting of green algae (Chlorella sp. and Scenedesmus sp.) and a blue-green alga (Tolypothrix sp.) as producers; an oligochaete (Aeolosoma hemprichi), rotifers (Lecane sp. and Philodina sp.) and a ciliate protozoan (Cyclidium glaucoma) as consumers; and more than four species of bacteria as decomposers. At 100 Gy, populations were not affected in any taxa. At 500-5000 Gy, one or three taxa died out and populations of two or three taxa decreased over time, while that of Tolypothrix sp. increased. This Tolypothrix sp. increase was likely an indirect effect due to interspecies interactions. The principal response curve analysis revealed that the main trend of the effects was a dose-dependent population decrease. For a better understanding of radiation risks in aquatic microbial communities, effect doses of gamma-rays compared with copper, herbicides and detergents were evaluated using the radiochemoecological conceptual model and the effect index for microcosm.
authors: Environmental Radiation Effects Research Group, National Institute of Radiological Sciences, Chiba 263-8555, Japan. fuma@nirs.go.jp
authors: Shoichi
authors: S
authors: Fuma
authors: Nobuyoshi
authors: N
authors: Ishii
authors: Hiroshi
authors: H
authors: Takeda
authors: Kiriko
authors: K
authors: Miyamoto
authors: Kei
authors: K
authors: Yanagisawa
authors: Kazutaka
authors: K
authors: Doi
authors: Isao
authors: I
authors: Kawaguchi
authors: Nobuyuki
authors: N
authors: Tanaka
authors: Yuhei
authors: Y
authors: Inamori
authors: Gennady G
authors: GG
authors: Polikarpov
mesh_terms: D000818:Animals; D017753:Ecosystem; D056890:Eukaryota / Q000528:radiation effects*; D020387:Food Chain; D005720:Gamma Rays; D006863:Hydrogen-Ion Concentration; D019216:Metals, Heavy / Q000009:adverse effects*; D009835:Oligochaeta / Q000528:radiation effects*; D016802:Oligohymenophorea / Q000528:radiation effects*; D011839:Radiation, Ionizing; D012403:Rotifera / Q000528:radiation effects*; D018675:Toxicity Tests; D014871:Water Microbiology; D014873:Water Pollutants / Q000009:adverse effects*; D014881:Water Supply
chemical_list: D019216:Metals, Heavy; D014873:Water Pollutants