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Lei-lei Luan

Bio: Lei-lei Luan is an academic researcher from Jinan University. The author has contributed to research in topics: Environmental science & Environmental chemistry. The author has an hindex of 2, co-authored 3 publications receiving 12 citations.

Papers
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Journal ArticleDOI
TL;DR: In this article, the distribution and structure of the zooplankton community in Pearl River Estuary were analyzed using a 1-year field investigation, and a total of 68 species were identified during the survey.
Abstract: Understanding the relationship between the zooplankton distribution and salinity may provide key information to understand ecosystem function under the condition of a global mean sea level rise caused by global climate change. However, little is known about how increasing salinity level will affect the entire zooplankton community on a large scale. Here we completed 1 year of field investigations on the Pearl River Estuary and analyzed the distribution and structure of the zooplankton community. A total of 68 zooplankton species were identified during the survey. The number and diversity (richness, evenness, Shannon index, and Simpson’s index) of the zooplankton species decreased as salinity increased from 0.10 to 21.26. Salinity negatively affected the abundances of rotifers, cladocerans, and total zooplankton, while it had little effect on copepod abundance. Some salt-tolerant species, such as Keratella tropica, Polyarthra vulgaris, and Paracalanus crassirostris, survived at high-salinity sites. A pattern was observed at all sites: the peak in copepod abundance always occurred when rotifers were abundant (sites S1 and S2) or after rotifer abundance reached a maximum level (sites S3, S4, and S5). In general, salinity was the most important environmental factor shaping zooplankton biodiversity and abundance. This study provides insight into potential biodiversity and structure of the zooplankton community in response to salinity change.

17 citations

Patent
19 Mar 2014
TL;DR: In this article, the utility model discloses a Gracilaria culturing net support resistant to fish damage and stormy waves, which comprises a frame, floats, a net, pile ropes, weights and seedling clamping ropes.
Abstract: The utility model discloses a Gracilaria culturing net support resistant to fish damage and stormy waves. The net support comprises a frame, floats, a net, pile ropes, weights and seedling clamping ropes. The frame is located on the water surface; the net has an open top end and is fixed on the frame, edges of the top end protruding upwards out of the water surface; the floats are fastened to the frame; one end of each pile rope is connected to the frame, and the other end is connected to a fixing object; the weights are hung at the bottom of the net; and the seedling clamping ropes are fastened onto the frame. The net support is used in sea areas with abundant herbivorous fishes such as Siganus, can effectively and economically prevent eating of Siganus, and has good resistance to stormy waves at the same time.

6 citations

Journal ArticleDOI
TL;DR: The hatching success of resting eggs of copepods and rotifers was affected by mariculture type, and that large-scale seaweed cultivation may offset the adverse effect of fish and shellfish cultivation on the resting eggs if integrated cultivation is adopted.
Abstract: The potential recruitment of resting eggs of calanoid copepods and rotifers to planktonic populations was investigated in the surface and sub-surface sediments of three mariculture zones: an integrated seaweed Gracilaria lemaneiformis and shellfish cultivation area (G), a fish cultivation area (F), and a shellfish cultivation area (S), as well as the sediments of a nearby control sea area (C) in a mariculture base in Southern China. The potential recruitment of copepod and rotifer eggs in the sediments of C and G was significantly higher than in F and S. Potential recruitment in the sub-surface sediments of F and S was not observed, suggesting that fish and shellfish mariculture may be responsible for this decrease. The hatching success of resting eggs of copepods and rotifers was affected by mariculture type, and that large-scale seaweed cultivation may offset the adverse effect of fish and shellfish cultivation on the resting eggs if integrated cultivation is adopted.

5 citations

Journal ArticleDOI
TL;DR: In this paper , the spectral characteristics of soil dissolved organic matter (DOM) under agricultural non-point source pollution in the Huaihe River Basin were studied using the parallel factor analysis method (PARAFAC).
Abstract: In order to study the spectral characteristics of soil dissolved organic matter (DOM) under agricultural non-point source pollution in the Huaihe River Basin, this study collected the soil from the Pihe River, a first-order tributary of the Zhengyangguan River, and used the parallel factor analysis method (PARAFAC) to obtain two components of humus and protein. Soil dissolved organic carbon (DOC) content was significantly different under different land use types (P<0.01). The soil DOM in the Huaihe River Basin is affected by both terrestrial and microbial sources. The biological index (BIX) of forest soil is significantly larger than that of cultivated land at different depths, which is caused by the rich plant diversity of forest land. The humification degree of cultivated land soil is higher than that of forest land, and the humification effect of cultivated land soil fertility is stronger due to human factors. The humification index (HIX), BIX and fluorescence index (FI) have a good indication of the degree of soil humification. At the same time, the greater the BIX, FI and spectral slope ratio (S R ), the greater the contribution of microorganisms to soil DOM.

Cited by
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Journal ArticleDOI
TL;DR: It is hypothesized that similar mechanisms at the organism level will lead to similar adaptive consequences at the population level across taxa, among which the formation of egg banks, the coexistence of species, and the possibility of differentiation among populations and local adaptation stand out.
Abstract: An in-depth look at the basic aspects of dormancy in cyclic parthenogenetic organisms is now possible thanks to research efforts conducted over the past two decades with rotifer dormant embryos. In this review, we assemble and compose the current knowledge on four central themes: (1) distribution of dormancy in animals, with an overview on the phylogenetic distribution of embryo dormancy in metazoans, and (2) physiological and cellular processes involved in dormancy, with a strong emphasis on the dormant embryos of cyclically parthenogenetic monogonont rotifers; and discussions of (3) the selective pressures and (4) the evolutionary and population implications of dormancy in these animals. Dormancy in metazoans is a widespread phenomenon with taxon-specific features, and rotifers are among the animals in which dormancy is an intrinsic feature of their life cycle. Our review shows that embryo dormancy in rotifers shares common functional pathways with other taxa at the molecular and cellular level, despite the independent evolution of dormancy across phyla. These pathways include the arrest of similar metabolic routes and the usage of common metabolites for the stabilization of cellular structures and to confer stress resistance. We conclude that specific features of recurrent harsh environmental conditions are a powerful selective pressure for the fine-tuning of dormancy patterns in rotifers. We hypothesize that similar mechanisms at the organism level will lead to similar adaptive consequences at the population level across taxa, among which the formation of egg banks, the coexistence of species, and the possibility of differentiation among populations and local adaptation stand out. Our review shows how studies of rotifers have contributed to improved knowledge of all of these aspects.

35 citations

Journal ArticleDOI
TL;DR: In this article, the authors identify the most sensitive taxa to seawater intrusion, establish maximum acceptable concentrations-environmental quality standards (MAC-EQSs) for sea water (SW) from species sensitivity distributions (SSDs), and compute risk quotients for the temperate zone.
Abstract: Seawater intrusion into low-lying coastal ecosystems carries environmental risks. Salinity levels at these coastal ecosystems may vary substantially, causing ecological effects from mortality to several sublethal endpoints, such as depression of rates of feeding, somatic growth, or reproduction. This review attempts to establish safe salinity levels for both terrestrial and freshwater temperate ecosystems by integrating data available in the literature. We have four specific objectives: (i) to identify the most sensitive ecological taxa to seawater intrusion; (ii) to establish maximum acceptable concentrations-environmental quality standards (MAC-EQSs) for sea water (SW) from species sensitivity distributions (SSDs); (iii) to compile from the literature examples of saline intrusion [to be used as predicted environmental concentrations (PECs)] and to compute risk quotients for the temperate zone; and (iv) to assess whether sodium chloride (NaCl) is an appropriate surrogate for SW in ecological risk assessments by comparing SSD-derived values for NaCl and SW and by comparing these with field data. Zooplankton, early life stages of amphibians and freshwater mussels were the most sensitive ecological receptors for the freshwater compartment, while soil invertebrates were the most sensitive ecological receptors for the terrestrial compartment. Hazard concentration 5% (HC5 ) values, defined as the concentration (herein measured as conductivity) that affects (causes lethal or sublethal effects) 5% of the species in a distribution, computed for SW were over 22 and 40 times lower than the conductivity of natural SW (≈ 52 mS/cm) for the freshwater and soil compartment, respectively. This sensitivity of both compartments means that small increments in salinity levels or small SW intrusions might represent severe risks for low-lying coastal ecosystems. Furthermore, the proximity between HC5 values for the soil and freshwater compartments suggests that salinized soils might represent an additional risk for nearby freshwater systems. This sensitivity was corroborated by the derivation of risk quotients using real saline intrusion examples (PECs) collected from the literature: risk was >1 in 34 out of 37 examples. By contrast, comparisons of HC5 values obtained from SSDs in field surveys or mesocosm studies suggest that natural communities are more resilient to salinization than expected. Finally, NaCl was found to be slightly more toxic than SW, at both lethal and sublethal levels, and, thus, is suggested to be an acceptable surrogate for use in risk assessment.

16 citations

Journal ArticleDOI
TL;DR: In this article, a bioavailability-based assessment of the HOC-stabilization efficacy of natural zeolites in maricultural sediments was performed using equilibrium passive sampling, and the results showed the bioaccumulations of four kinds of HOCs (including polycyclic aromatic hydrocarbons, polybrominated diphenyl ethers, pyrethroids, and organochlorine pesticides) in V. philippinaram were reduced by 7.3-38% after the natural zeolate amendment.
Abstract: As natural zeolites have been widely used as cost-effective adsorbents for plant nutrients and heavy metals in sediments, it is worthwhile to verify the potential of natural zeolites for mixed-contaminant stabilization including hydrophobic organic contaminants (HOCs). The effectiveness of natural zeolite amendment in sediment on reducing the bioaccumulation of sediment-associated HOCs in V. philippinaram (Cb) was assessed. Then, the role of sediment pore water freely dissolved HOCs (Cfree) in Cb prediction was further identified and modeled. In this study, a bioavailability-based assessment of the HOC-stabilization efficacy of natural zeolites in maricultural sediments was performed using equilibrium passive sampling. V. philippinaram was adopted as a biological indicator for HOC bioaccumulation. Polydimethylsiloxane (PDMS) was used as a passive sampler for monitoring the concentration of the Cfree. The assumption that Cfree is a central mediator driving the bioaccumulation process of HOCs from the bulk sediment to the exposed organisms was validated by correlating the reductions in Cb and Cfree of the sediments amended with natural zeolites. Subsequently, a model based on this assumption was built and verified for the bioavailability-based assessment of the stabilization efficacy of natural zeolite amendment on sediment-associated HOCs. The results showed the bioaccumulations of four kinds of HOCs (including polycyclic aromatic hydrocarbons, polybrominated diphenyl ethers, pyrethroids, and organochlorine pesticides) in V. philippinaram were reduced by 7.3–38% after the natural zeolite amendment (10% dry weight in sediments), and the Cfree values measured with PDMS were reduced proportionally. It supported the assumption that Cfree is a central mediator driving the bioaccumulation process of HOCs. Kow of HOCs and two properties of sediment were found to be significantly correlated with the reductions of the Cfree values. Based on these findings, a model to predict the Cb values of PAHs and PBDEs in V. philippinaram was built. The model was then verified by a significant correlation between the predicted and measured values of Cb. The potential of natural zeolites for the stabilization of mixed-contaminants in sediments, including HOCs, was proved as notable reductions of Cb and Cfree of HOCs in the sediments amended by natural zeolite were observed. The results also suggested PDMS is a promising tool for predicting the bioaccumulation of sediment-associated HOCs in V. philippinaram and further for assessing the stabilization efficacy of natural zeolites in maricultural sediments. Modifying natural zeolites to further improve the effectiveness of HOC stabilization is warranted.

11 citations

Journal ArticleDOI
TL;DR: In this paper , the effect of temperature, pH, turbidity, dissolved oxygen (DO), nitrate (NO3-), and phosphate (PO4³-) on the abundance of zooplankton of the River Adada, Nigeria was documented.
Abstract: Because of the pivotal role of zooplankton in most aquatic ecosystems; there is constant need to explore the effect of stressors (such as physicochemical properties of freshwater) on their abundance. We documented the effect of temperature, pH, turbidity, dissolved oxygen (DO), nitrate (NO3-), and phosphate (PO4³-) on the abundance of zooplankton of the River Adada, Nigeria. Using a manual pump, zooplankton were collected from three strategic stations from January to April (dry season) and June to September (rainy season). A total of 2,219 (dry = 945; rainy = 1,274) zooplankton occurred in the following descending order of abundance: copepods < rotifers < cladocerans < ostracods < insect larva. Whereas based on species number, cladocerans (n = 10) < copepods (n = 8) < rotifers (n = 7) < insect larva (n = 4) < ostracods (n = 2) occurred in this descending order. The downstream (station C) had more zooplankton (dry = 427; rainy = 391), followed by the mid-stream (station B; dry = 216; rainy = 591) and upstream (station A; dry = 302; rainy = 292). There was also a significant (P < 0.05) joint interactive effect of thermal condition on turbidity, pH, DO, PO4³- and NO3- to influence zooplankton abundance. Indicating that temperature is an important factor determining the assemblage of zooplankton in freshwater. Nevertheless, to assure an accurate evaluation of the effect of physicochemical parameters on zooplankton abundance in freshwater, future studies should include extended study periods and make use of more sophisticated trapping technique that would ensure the collection of a larger sample size with more species of zooplankton.

6 citations

Patent
13 Aug 2014
TL;DR: In this article, a seedling clamping type crassostrea hongkongensis middle incubation method is described, in which the seedlings are clamped and the two ends of the plastic ropes are knotted, a 0.2-0.5 kg cement block is fixed at the tail end of each plastic rope to be used as a counterweight block.
Abstract: The invention discloses a seedling clamping type crassostrea hongkongensis middle incubation method. The method comprises the following steps that (1) seedling clamping ropes are manufactured, wherein plastic ropes are cut, the length of the plastic ropes is 1.8-3 m, the diameter of the plastic ropes is 1.5-2.4 cm, each plastic rope is formed by two small ropes in a twisting mode, twist knots are arranged on the plastic ropes every 1.0-1.5 cm, the two ends of the plastic ropes are knotted, a 0.2-0.5 kg cement block is fixed at the tail end of each plastic rope to be used as a counterweight block, and manufacturing of the seedling clamping ropes is completed; (2) seedlings are clamped, wherein when young shells on a sheet-shaped plastic attaching piece are 2-10 mm in height, the twist knots in the step (1) are twisted off, fixing bases are clamped in the twist knots and fixed, and each seedling clamping rope is fixedly provided with 10-15 fixing bases; (3) middle incubation is conducted, wherein each seedling clamping rope with seedlings well clamped in the step (2) is placed in an ecological soil pool or a natural sea area, and the seedling clamping ropes are hung on a floating object for conducting middle incubation. The seedling clamping type crassostrea hongkongensis middle incubation method has the advantages that operation is convenient, time and labor are saved, the corrosion resistance capacity is high, the yield is large, and the benefits are high.

5 citations