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Distribution Pattern Of Rotifera And Correlation To Its Environmental Factors In The Huaihe River Basin

Posted on:2015-10-28Degree:MasterType:Thesis
Country:ChinaCandidate:K ZhaoFull Text:PDF
GTID:2181330431468770Subject:Aquatic biology
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The Huaihe River is located in eastern China, between the Yangtze and YellowRiver basins and flows through four provinces: Henan, Anhui, Shandong and Jiangsu.The Huaihe River basin area is about270,000km2with a total length of1,000km andis China’s sixth largest and most densely populated basin. The basin containsimportant social and economic resources including transportation, hydropower,irrigation, and drinking-water reservoirs. Furthermore, the Huaihe River basincontains vast agricultural areas representing China’s major grain and cottonproduction. However, the Huaihe River basin is ecologically sensitive and currentlyfaces several environmental challenges including frequent flooding, severe waterpollution and ecological degredation. The Huaihe River basin is selected as one ofChina’s Science and Technology (ST) National Water Pollution Control andGovernance (water special) model watersheds to develop scienitific understanding ofwater pollution control and aquatic ecosystem protection. The river basin is also the“River Pollution Control District” in both the “Eleventh Five-Year” and “TwelfthFive-year” plans. Therefore, environmental research of the river and its tributarynetwork has important ecological and social significance in the Huaihe River basin.Rotifers are one kind of zooplankton that live in rivers throughout the world.Rotifers occupy the middle link in the food chain between phytoplankton and fish andthus represent an important biologic component of aquatic ecosystems. Rotiferaspecies composition and community structure can be affected by environmentalconditions and their sensitivity to water pollution makes them useful for environmental monitoring. This research examines the use of Rotifers as indicators ofenvironmental pollution in the Huaihe RiverFor this thesis, Rotifera were collected from217sites throughout the rivernetwork to investigate the relationship between the Rotifera community andenvironmental conditions, and to investigate the use of Rotifers in water qualitymonitoring and pollution governance in the Huaihe River. This research will not onlyprovide important information about Rotifera diversity, but also present basicunderstanding about the relationships between Rotifers and environmental conditionsacross the Huaihe River basin. The results of this research also provide importantecological knowledge that is needed to assess and monitor water quality, and todevelop pollution control strategies in the Huaihe River basin as well as other largerrivers in China. The main results of the research are as follows:1、A wide range of Rotifers were observed in the Huaihe River network. FromApril to May in2013,187species of Rotifers were collected (including13subspecies)belonging to2classes,3orders,22families, and41genera. The most commonRotifers were found in the Monogonota class, which contained2orders,20families,37genera and179species. Digonota was also common and contained1order,2families,4genera and8species. The most abundant species collected wereTrichocerca, Brachionus, Lecane, Lepadella. Rotifera abundance in the Huaihe RiverBasin network was highly variable and ranged from17to115017ind./L (mean=4638), and Rotifera biomass ranged from0.00167to43.024mg/L (mean=2.3057mg/L).2、Of the four administrative regions of the Huaihe River Basin,106species ofRotifers were found in Henan Province,89species in Anhui Province,76species inShandong Province and96species in Jiangsu Province. The maximum number andbiomass of Rotifers were found in the Shandong Province with7868ind./L and a3.8916mg/L respectively. The minimum number and biomass were found in theHenan Province with2628ind./L and1.6395mg/L respectively. The pioneer speciesPolyarthra sp. was the dominant Rotifera present in the Henan, Anhui and JiangsuProvinces. While in the Shandong Province,. Keratella cochlearis was the dominant pioneer species. In the Henan, Anhui and Jiangsu Provinces there were a total of5dominant species and4dominat species in the Shandong Province.3、The Strahlar method was used to divide the Huaihe River Basin into sixcategories based on stream order. In first order streams63species rotifers wereidentified,133species were in2ndorder streams,106species were in3rdorder streams,65species were in4thorder streams,42species were in5thorder streams and17species were in6thorder streams. Sampling effort was related to number of speciesfound and was highest in2ndorder and lowest in6thorder streams. Rotifers abundancedecreased from1stto5thorder streams, while at the same time the biomass generallyincreased. The highest abundance was found in1storder streams (5839ind./L) andlowest in5thorder streams (2604ind./L). The lowest biomass was found in1storderstreams (1.4468mg/L), and the highest in5thorder streams (3.4541mg/L).The number of dominant species was highest in2ndorder streams and lowest in1storder streams. From1stto5thorder, the type of pioneer dominant species changedfrom Kre.-Pol. Type→Pol.-Kre. type→Pol. type→Pol. type→Syn.-Pol.type. The size of pioneer dominant Rotifers increased from1stto5thorder streams4、Pearson correlation analysis showed that chemical oxygen demand (COD) wassignificantly correlated with a variety of biological indicators. The pioneer dominantand representative species, Polyarthra sp. was significantly positively correlated withCOD and pH, and was also significantly negatively correlated with total nitrogen tototal phosphorus ratio (TN/TP).Canonical Correspodnace Analysis (CCA) ordination shows that COD and TPwere the main environmental factors affecting the distribution of Rotifers in HenanProvince. TN/TP and COD were the main environmental factors affecting thedistribution of Rotifers in Anhui Province. Turbidity, TN and TP mainly affect thedistribution of Rotifers in Shandong Province and TP mainly affect the distribution ofRotifers in Jiangsu Province.COD, DO and pH were the main environmental factors affecting the distributionof Rotifers in1storder streams. Water tempetature (WT), TN and DO were the mainenvironmental factors affecting the distribution of Rotifers in2ndorder streams. TP was the main environmental factor affecting the distribution of Rotifers in3rdorderstreams. COD, WT and TN were the main environmental factors affecting thedistribution of Rotifers in4thorder streams. And TN/TP, DO and TP were the mainenvironmental factors affecting the distribution of Rotifers in5thorder streams.5、The results of this research suggest that Huaihe River Basin may be pollutedby human activities in the basin and that Rotifers may be a useful organism formonitoring the health of the Huaihe River and it’s associated tributary network.Furthermoe the findings of this research have the potential to be used as a model formonitoring other large rivers in China.
Keywords/Search Tags:The Huaihe River Basin, Rotifera, Community structure, Environmentalfactors, Water quality evaluation
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