Environmental Factors Affecting Freshwater Snail Intermediate Hosts in Shenzhen and Adjacent Region, South China.

Sound knowledge of the local distribution and diversity of freshwater snail intermediate hosts and the factors driving the occurrence and abundance of them is crucial to understanding snail-borne parasitic disease transmission and to setting up effective interventions in endemic areas. In this study, we investigated the freshwater snails, water quality parameters, physical characteristics of habitats, predators and competitors, and human activity variables at 102 sites during December 2018 and August 2019 in Shenzhen and adjacent areas in China. We used decision tree models and canonical correspondence analysis to identify the main environmental and biotic factors affecting the occurrence and abundance of snail species.

Fabrication of HO slow-releasing composites for simultaneous Microcystis mitigation and phosphate immobilization.

Hydrogen peroxide (HO) is a widely accepted algicide in controlling cyanobacterial blooms. However, this method includes two disadvantages: 1) a low HO concentration (<5 mg L) is required; 2) HO-induced cell lysis causes phosphorus (P) contamination. To overcome the drawbacks, a HO slow-releasing composite (HSRC) based on calcium peroxide (CaO) was fabricated to substitute liquid HO.

Response of phytoplankton to banana cultivation: A case study of Lancang-Mekong River, southwestern China.

This study examined the possible effects of banana cultivation on phytoplankton biomass and community structure in southwest China along the Lancang-Mekong River. Water and phytoplankton samples were collected on March (dry season) and August (rainy season), and physical-chemical properties of water, phytoplankton biomass and community structure were determined. The results indicated that the banana cultivation resulted in increases in sediment, total phosphorus (TP) and total nitrogen (TN) concentrations at estuaries of Lancang-Mekong River branches.

[Challenges and countermeasures for water conservancy combined with schistosomiasis prevention and control in China in new era].

The spread of schistosomiasis seriously threaten the health of people and hinder the economic and social development in China. The water conservancy combined with schistosomiasis prevention and control effectively controlled the spread of schistosomiasis by controlling the spread of , the only intermediate host of . This paper reviews the evolution of the strategy of schistosomiasis prevention and control in China and points out the historical role of water conservancy combined with schistosomiasis prevention and control.

Spatiotemporal patterns of surface-suspended particulate matter in the Three Gorges Reservoir.

An investigation was conducted in the Three Gorges Reservoir (TGR) seasonally from September 2010 to June 2011 to screen the distribution pattern of suspended particulate matter (SPM). Concentration of SPM, particulate nitrogen (PN), particulate phosphorus (PP), bioavailable particulate phosphorus (BAPP), and chlorophyll a (Chl a) were determined synchronously. Concentration of SPM was higher in the flood season than in the dry season and higher in the mainstream than in the tributaries.

[Relationship between pCO2 and algal biomass in Xiangxi Bay in spring].

Water temperature (WT), pH, HCO3-, dissolved oxygen and the concentration of Chl-a in Xiangxi Bay were measured in spring. The partial pressure of carbon dioxide was calculated by the chemical balance and Henry's Law while CO2 flux by the thin-layer diffusion model. Results showed that pCO2 of surface water in Xiangxi Bay varied from 8.

[Diurnal changes in greenhouse gases at water-air interface of Xiangxi River in autumn and their influencing factors].

With the closed chamber and gas chromatography method, a 24-hour continuous monitoring was carried out to understand the greenhouse gases fluxes across the water-air interface of the Xiangxi River Bay, the Three-Gorges Reservoir in Autumn. Results indicated that the fluxes of CO2, CH4 and N2O across the water-air interface showed an obvious diurnal variation. The absorption and emission process of CH4 showed strong diurnal variation during the experimental period, reaching the highest emission at 1 am, whereas CO2 and N2O were emitted all day.

Responses of phytoplankton functional groups to the hydrologic regime in the Daning River, a tributary of Three Gorges Reservoir, China.

Daning River is a deep tributary of Three Gorges Reservoir (TGR) in China, with water level fluctuations of 30 m annually. It was assumed that the hydrologic regime would be the main driving force in the self-assembling of the phytoplankton community in the river. In order to test this hypothesis, limnological study was performed monthly in the estuary, midstream and upstream of this tributary from May 2008 to April 2009.

Contamination status of dioxins in sediment cores from the Three Gorges Dam area, China.

In order to screen dioxin pollution in sediment of Three Gorges Dam (TGD) area, three sediment cores were obtained from two sites in 2010~2011; each core was divided into different samples with every 10 cm depth. Sediment dating determined by radiometry ((137)Cs, (210)Pb) and concentrations of dioxins were analyzed by high-resolution gas chromatography/mass spectrometry. The results indicated: Sediment dating showed no significant difference among all the samples from the same core and the two locations (ANOVA, p>0.

Temporal variation and spatial distribution of PAH in water of Three Gorges Reservoir during the complete impoundment period.

Bioavailable concentrations of polycyclic aromatic hydrocarbons (PAHs) were investigated in water of Three Gorges Reservoir (TGR) using semipermeable membrane devices during the period of completely impounding water. ∑PAH concentrations in water of TGR in the period of completely impounding water were 15-381 ng L(-1). ∑PAH concentrations increased from town or counties to big industrialized cities in TGR, indicating urbanization effects on PAH pollution in the water.

Phytoplankton variation and its relationship with the environment in Xiangxi Bay in spring after damming of the Three-Gorges, China.

Following the completion of the Three-Gorges Dam, there was a strong spring phytoplankton bloom in Xiangxi Bay of Three-Gorges Reservoir. However, our knowledge of relationship between spring phytoplankton bloom and environmental factors was still limited. In this study, phytoplankton species composition, biomass, chlorophyll a concentration and environmental factors at two sampling sites in Xiangxi Bay were investigated during 25 March to 18 May 2007.

Determination of PAH, PCB, and OCP in water from the Three Gorges Reservoir accumulated by semipermeable membrane devices (SPMD).

Bioavailable water concentrations of polycyclic aromatic hydrocarbons (PAH), polychlorinated biphenyls (PCB) and organochlorine pesticides (OCP) were measured in the water column from Three Gorges Reservoir (TGR) collected in May 2008 using semipermeable membrane devices (SPMDs). The sampling sites spanned the whole reservoir from the upstream Chongqing to the great dam covering more than 600 km long distance with water flow velocities ranging from <0.05 to 1.