7.3.11 3,4-Dichloroaniline
The effect of 3,4-dichloroaniline (3,4-DCA) was investigated by Dr. Sugiura.
3,4-Dichloroaniline was added at the start of the microcosm culture (day 0), and
the number of organisms (abundance) and amounts of respiration and production
were tracked. With the addition of 3,4-DCA, both the respiration volume and
production volume became larger than in the control system. The m-NOEC of
3,4-DCA was estimated to be 1 mg/L (Sugiura 1992).
7.3.12 Paraquat
The effect of paraquat was investigated by Dr. Sugiura. Paraquat was added at the
start of the microcosm culture (day 0), and the number of organisms and amount of
respiration and production were tracked. The m-NOEC was estimated to be 0.01 mg/
L (Sugiura 1992).
7.3.13 2,4,5-Trichlorophenoxyacetic Acid (2,4,5-T)
The effect of 2,4,5-trichlorophenoxyacetic acid (2,4,5-T) was investigated by
Dr. Sugiura. 2,4,5- Trichlorophenoxyacetic acid was added at concentrations of
0.1, 1.0, 10, and 100 mg/L at the start of the microcosm culture (day 0). The change
over time in the population density and community metabolism with the addition of
10 mg/L did not differ from those of the control system. In the 100 mg/L addition
system, Philodina erythrophthalma, Aeolosoma hemprichi, Scenedesmus
quadricauda, and Tolypothrix sp. perished, and the change over time in the community metabolism also differed greatly from the control system. From these results,
the addition of 10–100 mg/L of 2,4,5-T was estimated to have affected this system
(Sugiura 1992).
7.3.14 Cafenstrole
On the 16th day after the start of the microcosm culture (stationary phase),
cafenstrole was added at concentrations of 0, 0.5, 1.0, 2.5, and 5.0 mg/L. The
influence exerted by this chemical on the microorganisms constituting the microcosm depended upon the concentration added. At an addition concentration of
0.5 mg/L, Cyclidium glaucoma, Lecane sp., and Aeolosoma hemprichi began to be
affected, with Aeolosoma hemprichi being affected at 1.0 mg/L, and both Aeolosoma
hemprichi and Cyclidium glaucoma disappeared within 2 days after the addition of
7 Example Assessments of the Microcosm N-System
93
The effect of 3,4-dichloroaniline (3,4-DCA) was investigated by Dr. Sugiura.
3,4-Dichloroaniline was added at the start of the microcosm culture (day 0), and
the number of organisms (abundance) and amounts of respiration and production
were tracked. With the addition of 3,4-DCA, both the respiration volume and
production volume became larger than in the control system. The m-NOEC of
3,4-DCA was estimated to be 1 mg/L (Sugiura 1992).
7.3.12 Paraquat
The effect of paraquat was investigated by Dr. Sugiura. Paraquat was added at the
start of the microcosm culture (day 0), and the number of organisms and amount of
respiration and production were tracked. The m-NOEC was estimated to be 0.01 mg/
L (Sugiura 1992).
7.3.13 2,4,5-Trichlorophenoxyacetic Acid (2,4,5-T)
The effect of 2,4,5-trichlorophenoxyacetic acid (2,4,5-T) was investigated by
Dr. Sugiura. 2,4,5- Trichlorophenoxyacetic acid was added at concentrations of
0.1, 1.0, 10, and 100 mg/L at the start of the microcosm culture (day 0). The change
over time in the population density and community metabolism with the addition of
10 mg/L did not differ from those of the control system. In the 100 mg/L addition
system, Philodina erythrophthalma, Aeolosoma hemprichi, Scenedesmus
quadricauda, and Tolypothrix sp. perished, and the change over time in the community metabolism also differed greatly from the control system. From these results,
the addition of 10–100 mg/L of 2,4,5-T was estimated to have affected this system
(Sugiura 1992).
7.3.14 Cafenstrole
On the 16th day after the start of the microcosm culture (stationary phase),
cafenstrole was added at concentrations of 0, 0.5, 1.0, 2.5, and 5.0 mg/L. The
influence exerted by this chemical on the microorganisms constituting the microcosm depended upon the concentration added. At an addition concentration of
0.5 mg/L, Cyclidium glaucoma, Lecane sp., and Aeolosoma hemprichi began to be
affected, with Aeolosoma hemprichi being affected at 1.0 mg/L, and both Aeolosoma
hemprichi and Cyclidium glaucoma disappeared within 2 days after the addition of
7 Example Assessments of the Microcosm N-System
93