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Author

Danni Yuan

Other affiliations: Chinese Academy of Sciences
Bio: Danni Yuan is an academic researcher from Jinan University. The author has contributed to research in topics: Species evenness & Salinity. The author has an hindex of 1, co-authored 1 publications receiving 2 citations. Previous affiliations of Danni Yuan include Chinese Academy of Sciences.

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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


Cited by
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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 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

Journal ArticleDOI
TL;DR: In this paper, the spatio-temporal variation of phytoplankton and zooplankts assemblages in Kavaratti lagoon and offshore water of Lakshadweep archipelago, India was analyzed.
Abstract: This paper summarizes the spatio-temporal variation of phytoplankton and zooplankton assemblages in Kavaratti lagoon and offshore water of Lakshadweep Archipelago, India. The objective of this study was to evaluate phytoplankton and zooplankton assemblage with responses to changing environmental conditions in Kavaratti lagoon and offshore water. Samples were collected and analysed during the pre-monsoon and post-monsoon season during 2016. During this period, in total, 69 species of zooplankton and 54 species of phytoplankton were identified. The population density of various groups of zooplankton found to be of the following order: Crustacea > Foraminifera > Porifera > Chaetognatha > Ciliophora > Appendicularia. Similarly, phytoplankton composed of the order of Bacillariophyceae > Dinophyceae > Chlorophyceae > Cyanophyceae. The highest population densities were recorded in the pre-monsoon period of the study. The lagoon region recorded the maximum plankton distribution than the offshore region. Crustaceans exhibit maximum diversity and richness in all the stations and seasons studied. Macrosetella gracilis (711 nos/m3) was the most dominant zooplankton species observed and which may be attributed to the availability of preferential food and favorable environmental conditions. There is a significant effect of water salinity on the population density of Daphnia magna (652 nos/m3) has been noticed during the pre-monsoon season of the study. Daphnia magna is well adapted to certain fluctuations, such as low oxygen conditions, high pH, wide ranges of salinity, and temperature. Among the phytoplankton, diatoms, such as Bellerochea malleus (20,160 nos/m3), Coscinodiscus gigas (1180 nos/m3), Eucampia zodiacus (880 nos/m3), and Rhizosolenia alata (2380 nos/m3), were dominant during the study. The Shannon–Wiener Diversity Index (0.183–2.587) for phytoplankton represents moderate level of pollution in the Kavaratti Island. The canonical correspondence analysis (CCA) confirms that the positive correlation of environmental parameters, such as water temperature, salinity, ammonia, nitrates, and silicates, on the distribution and assemblages of the plankton community.

1 citations