Environmental Engineering Reference
In-Depth Information
changing the soil microbial population (Wavre and Brinkhurst 1971; Kikuchi and
Kurihara 1977), and providing a food source for aquaculture species (Aston et al. 1982;
Marian and Pandian 1984).
11.2.1.1  Effects of Organochlorine on Rotifers
OCPs are toxic in both vertebrates and invertebrates. Many studies have shown that
OCPs have reduced the reproductive success of raptors such as the Bald eagle Haliaeetus
leucocephalus (Bowerman et al. 1995; Clark et al. 1998) and disrupted the sex hormones
in reptiles such as the American alligator Alligator mississippiensis (Guillette et al. 1994)
and common snapping turtle Chelydra serpentina (de Solla et al. 1998). Furthermore,
OCPs have disrupted estrogenic hormones in mammals. These reproductive compli-
cations may be due to the bioaccumulation of OCPs in high trophic level animals.
Invertebrate organisms are at the base of the food chain and take up and transfer
OCPs into the aquatic food chain. Studies have shown that OCPs, such as aldrin, can
significantly affect the duration of embryonic development of the rotifer Brachionus
calyciflorus pallas at concentrations ranging from 0.04 to 1.28 mg/L (Huang et al. 2007).
In addition, the OCPs DDT, dicofol, endosulfan, and lindane have been shown to sig-
nificantly decrease the population growth rate and reproduction of B. calyciflorus (Xi
et al. 2007).
11.2.1.2  Effects of Organophosphorus on Rotifers
OPPs are known to adversely affect rotifers. Ke et al. (2009) reported that OPPs such as
dichlorvos, triazophos, and chlorpyrifos have a significant effect on the population growth
rate of the freshwater rotifer B. calyciflorus in China. Studies showed that rotifers died
after being exposed to 10,000 μg/L of chlorpyrifos in a 24-h time period. Reproductive
effects from diazinon and fenitrothion were tested using B. plicatilis . The results showed
that diazinon and fenitrothion were highly acutely toxic with a 24-h LC 50 of 88.39 μM and
229.76 μM, respectively (Marcial et al. 2005).
11.2.2  Effect of Pesticides on Phylum Mollusca
Mollusks, such as apple snails, Pomacea canaliculata , are major pests in rice fields. Apple
snails damage crops, particularly rice, by feeding on germinating seeds and young
seedlings. Crops in many countries in Southeast Asia such as Thailand, Vietnam, and
Cambodia are affected by these species. Farmers usually use molluscicides to control these
pests. Molluscicides, known as snail bait and snail pellets, are used in agriculture or gar-
dening to control gastropod pests such as slugs and snails that can damage crops. For
example, endosulfan is a common chlorinated molluscicide used in agriculture to kill mol-
lusks in Thailand.
11.2.2.1  Effect of Organochlorine on Mollusks
OCPs are known to be potential endocrine disruptors. Residues from DDT and its
derivatives affect gonad development and cause reproductive abnormalities in mollusks
(Binelli et al. 2004). Long-term exposures to OCPs can also affect the freshwater snail,
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