glaucoma decreased remarkably and then recovered with the addition of 10 mg/L of
fenitrothion. Thus, there was a recognized influence from this pesticide on
microanimals in the microcosm. In contrast, the microalgae, Chlorella sp.,
Scenedesmus quadricauda, and Tolypothrix sp., were not influenced by the addition
of less than 10 mg/L of Fenitrothion. The functional parameter, the quantity of
production (P) and respiration (R), increased in comparison with the no-addition
control system. There was no difference between the P/R ratios of systems with
Fenitrothion concentrations ranging from 0.01 to 10 mg/L and the acetone-only
control system. The P/R ratio did not change with the addition of Fenitrothion
(Fig. 7.16).
To understand the effects of Fenitrothion, an ANOVA was performed between the
acetone-only control system and each Fenitrothion addition system, but no meaningful
difference was recognized in the amounts of production and respiration or in the P/R
ratios of each microcosm; the influence of the Fenitrothion concentration remained the
same. The NOEC of Fenitrothion varied widely by species; it is reported as 0.009 mg/
L for Daphnia magna, a very small amount, whereas it was ~1.0 mg/L for rotifers and
microalgae. To focus on the constituent animals of the microcosm, because the
abundance of Aeolosoma hemprichi decreased with the addition of 0.1 mg/L of
Fenitrothion and Aeolosoma hemprichi and two species of rotifer, Philodina
erythrophthalma and Lecane sp., perished with the addition of 10 mg/L of
Fenitrothion, it may be said that influence at the same level as the aquatic animal
that tolerance is relatively strong. However, even at the concentration at which
constituent animals in the microcosm perished, there was no observed influence by
Fenitrothion alone on the amounts of production and respiration.
7.4.3 Lindane
Lindane was added to the microcosm N-system on the 16th day after cultivation
began (stationary phase) at concentrations of 0.003, 0.03, and 0.12 mg/L. There was
no statistically significant difference between the addition and control systems, and
stable production and respiration amounts were maintained that were equal to those
in the control system, at Lindane concentrations of 0.003, 0.03, and 0.12 mg/L
(Fig. 7.17). It was estimated that the m-NOEC of Lindane is greater than 0.12 mg/L.
7.4.4 Carbendazim
A benrate hydration agent was supplied for investigation. A benrate hydration agent
is a main product of Carbendazim, composed primarily of approximately 50% of
benomyl, and the benomyl is converted into Carbendazim underwater, having a halflife of 2 h. The addition concentration of Carbendazim was adjusted to 0.1, 1.0, 3, 5,
and 10 mg/L, and it was added on the 16th day of the stable state into the microcosm.
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K. Murakami et al.
fenitrothion. Thus, there was a recognized influence from this pesticide on
microanimals in the microcosm. In contrast, the microalgae, Chlorella sp.,
Scenedesmus quadricauda, and Tolypothrix sp., were not influenced by the addition
of less than 10 mg/L of Fenitrothion. The functional parameter, the quantity of
production (P) and respiration (R), increased in comparison with the no-addition
control system. There was no difference between the P/R ratios of systems with
Fenitrothion concentrations ranging from 0.01 to 10 mg/L and the acetone-only
control system. The P/R ratio did not change with the addition of Fenitrothion
(Fig. 7.16).
To understand the effects of Fenitrothion, an ANOVA was performed between the
acetone-only control system and each Fenitrothion addition system, but no meaningful
difference was recognized in the amounts of production and respiration or in the P/R
ratios of each microcosm; the influence of the Fenitrothion concentration remained the
same. The NOEC of Fenitrothion varied widely by species; it is reported as 0.009 mg/
L for Daphnia magna, a very small amount, whereas it was ~1.0 mg/L for rotifers and
microalgae. To focus on the constituent animals of the microcosm, because the
abundance of Aeolosoma hemprichi decreased with the addition of 0.1 mg/L of
Fenitrothion and Aeolosoma hemprichi and two species of rotifer, Philodina
erythrophthalma and Lecane sp., perished with the addition of 10 mg/L of
Fenitrothion, it may be said that influence at the same level as the aquatic animal
that tolerance is relatively strong. However, even at the concentration at which
constituent animals in the microcosm perished, there was no observed influence by
Fenitrothion alone on the amounts of production and respiration.
7.4.3 Lindane
Lindane was added to the microcosm N-system on the 16th day after cultivation
began (stationary phase) at concentrations of 0.003, 0.03, and 0.12 mg/L. There was
no statistically significant difference between the addition and control systems, and
stable production and respiration amounts were maintained that were equal to those
in the control system, at Lindane concentrations of 0.003, 0.03, and 0.12 mg/L
(Fig. 7.17). It was estimated that the m-NOEC of Lindane is greater than 0.12 mg/L.
7.4.4 Carbendazim
A benrate hydration agent was supplied for investigation. A benrate hydration agent
is a main product of Carbendazim, composed primarily of approximately 50% of
benomyl, and the benomyl is converted into Carbendazim underwater, having a halflife of 2 h. The addition concentration of Carbendazim was adjusted to 0.1, 1.0, 3, 5,
and 10 mg/L, and it was added on the 16th day of the stable state into the microcosm.
96
K. Murakami et al.