The impact of earlier flood recession on metacommunity diversity of wintering waterbirds at shallow lakes in the middle and lower Yangtze River floodplain

The hydrological regime in wetlands plays an important role in the process of wintering waterbird metacommunity assemblage.However,increasing frequency of extreme climate and the intensification of human activities,such as the construction of sluices and dams,have resulted in frequently abnormal hydrological regime in the middle and lower Yangtze River floodplain.In recent years,earlier flood recession has become one of the main hydrological problems faced in the shallow lakes,having a great impact on wetland biodiversity.It is necessary to understand the impact of earlier flood recession on waterbirds,an indicator of wetland biodiversity,and the metacommunity concept is helpful to elucidate the underlying mechanism involved in the processes of assemblage by waterbird communities.In this study,we surveyed the wintering waterbirds at three sub-lakes of Caizi Lakes during 2019-2020 and 2020-2021 and compared the richness,abundance,alpha and beta diversity of waterbirds in and among local metacommunities under earlier flood recession and normal hydrological regime.The results showed that the earlier flood recession reduced the species richness in the early stage and abundance in the late stage,it also reduced the Shannon-Wiener index in the early stage and increased the dissimilarity between and within waterbird metacommunities in the late stage.The partition of beta diversity showed that the turnover component played a major role in the process of waterbird metacommunity assemblage.It was found that the earlier flood recession reduced the richness,abundance in different stages of flood recession,which also increased the turnover of waterbirds.Metacommunities with high habitat heterogeneity had better resistance to abnormal hydrological regime,which resulted in high dissimilarity between and within metacommunities.The results of this study provide important information for waterbird conservation and water level management at shallow lakes in the middle and lower Yangtze River floodplain.

Do alternative stable states exist in large shallow Taihu Lake,China?

Regime shifts from submersed macrophyte dominance to phytoplankton dominance have been widely reported in small-to medium-sized shallow lakes.However,alternative stable states in large shallow lakes(surface area>500 km^(2))remain unconfirmed.To understand the alternative stable states and the main influencing factors of submersed macrophytes in large lakes,the ecosystem states from monitoring data from 1959 to 2019 in large shallow Taihu Lake(2338 km^(2)in average depth of 2.12 m)in China were examined.Changes in submersed macrophyte coverage(C_(Mac))and phytoplankton chlorophyll a(Chl a)in the time series and their relationships with environmental factors were analyzed.During the field investigation from August 2018 to May 2019,nutrients and Chl a showed obvious heterogeneity across the lake,being generally higher in the western and northern areas and lower in the southeast area,while C_(Mac)was only observed in the eastern areas,e.g.,East Taihu Lake,Xukou Bay,and Gonghu Bay.During the long-term monitoring from 1959 to 2019 in the Central Region,Meiliang Bay,and East Taihu Lake,Chl a increased significantly in the time series.C_(Mac)varied slightly among different subareas,always at low levels(<10%)in the Central Region and Meiliang Bay but at relatively high levels in East Taihu Lake(10%–90%).Frequency distributions of response variables had no multimodality except for C_(Mac)in East Taihu Lake,with two peaks between 15%and 20%and between 55%and 60%.A dual relationship was found between Chl a and total phosphorus(TP)in the areas with and without macrophytes,while C_(Mac)showed no relationship with TP,and submersed macrophytes did not flourish in the Central Region and Meiliang Bay even when TP was at very low levels(≈10 mg/m3).Taihu Lake had similar algal turbidity(TurbAlg)as small-to mediumsized lakes but generally presented with higher values of nonalgal turbidity(TurbNonAlg),as did their contribution to total turbidity as a percentage.This study suggested that large shallow Taihu Lake may have no alternative stable states,but more evidence is needed for East Taihu Lake,which was dominated by macrophytes,as it remains unknown whether hysteresis occurs between the processes of eutrophication and oligotrophication.Unfavorable conditions caused by wind might be the main reason due to the absence of submersed macrophytes in Taihu Lake.These results demonstrate that stricter nutrient control is needed to maintain a healthy state or to recover from a decayed state for large lakes.

Geochemical Forms of Phosphorus in Sediments of Three Large, Shallow Lakes of China

A sequential extraction method for the fractionation of phosphorus （P） in lake sediments was used to analyze phos- phorus fractions of sediments taken from three large, shallow. eutrophic freshwater lakes of China-Talhu Lake. Chaohu Lake, and Long.an Lake. All three lakes are located in the lower reaches of the Changjiang River （Yangtze River）. In Taihu Lake and Chaohu Lake, algae blooms occurred every year, while Longgan Lake was a macrophyte-dominated lake. Results showed that exchangeable phosphorus fractions were much higher in the eutrophic lake sediments than in the macrophyte-flourishing lake sediment. Also, the ratio of Fe：P in the sediments of the algae-predomlnant lakes was generally much lower than that in the macrophyte-predominant lakes. Thus, the geochemical fractions of phosphorus in sediments had a closer relationship with the type of aquatic vegetation.

ABUNDANCE AND PRODUCTION OF BRANCHIURA SOWERBYI (OLIGOCHAETA: TUBIFICIDAE) IN TWO TYPICAL SHALLOW LAKES (HUBEI, CHINA)

An April 1996 to March 1997 comparative study on the abundance and secondary production of Branchiura sowerbyi Beddard, 1892 in two typical shallow lakes showed that in Houhu, an algae dominated lake, the worm density (68 ind·m -2 ) peaked in July, biomass (1.930 g·m -2 ) peaked in June, while in Biandantang, a macrophyte dominated lake, standing stock (density:60 ind·m - 2 ; biomass:1.019 g·m -2 in wet weight) peaked in December. Secondary production of the animal in Houhu Lake was 3.413 g wet wt m -2 a -1 , a little more than that (2.675 g wet wt m -2 a -1 ) in Biandantang Lake. Their turnover rates (P/B ratios) were 4.0 and 5.0, respectively.

Analysis on the Chemical Characteristics of Shallow Groundwater and Causes of Formation in the Area around Poyang Lake

[Objective] The study aimed at analysing the chemical characteristics of shallow groundwater and causes of formation around Poyang Lake area. [Method] The quality of shallow groundwater under seven counties or cities around Poyang Lake was investigated in 2010, and compared different regions from salinity, hardness, conductivity, hydrochemistry types and so forth, so as to reveal the status quo, change characteristics and reasons of shallow groundwater. [Result] Except for pH, other water quality indicators of shallow groundwater around Poyang Lake were better, attaining Class I water quality standards. Among these regions, the salinity, hardness, conductivity, Na+, K+, Ca2+, Mg2+, Cl- and HCO-3 concentration of shallow groundwater in Nanchang city were up to the maximum values, while pH and SO2-4 concentration were the highest in Duchang County; Mg2+ concentration and pH were the lowest in Poyang County, and hardness, K+, Ca2+, SO2-4 and Cl- concentration in Yongxiu County reached the minimum values, while Na+ concentration, salinity and conductivity were the lowest in Jinxian County. In addition, the better quality of groundwater around Poyang Lake was closely related to the low level of economic development in Jiangxi Province. Meanwhile, many water quality indices in Nanchang City reached the maximum values, and even tended to Class Ⅱ water quality standards, which resulted from the high level of economic development and decisive role of human activities. [Conclusion] The research could provide references for the establishment of management strategies for regional shallow groundwater.

A New Understanding of Channel Patterns and Facies Models of the Shallow Lake Delta Facies of Fuyu Oil Reservoir in Songliao Basin,China

In the Fuyu Reservoir of Songliao Basin, there occur a series of well-developed peculiar shallow lake delta facies, which can be divided to such three ones as the upper delta plain subfacies, the lower delta plain subfacies, and the delta front subfacies. Among them the upper delta plain subfacies mainly grows proximal distributary channels; the lower delta plain subfacies mainly grows distal ones. The entire Fuyu Reservoir has mainly developed 7 kinds of distributary channel patterns： proximal/ distal meandering type distributary channels, proximal/distal low-sinuosity type distributary channels, proximal/distal straight type distributary channels, and subaqueous distributary channels. Among these patterns, the proximal and distal meandering type distributary channels have bigger thickness of point bar and better sorting and low content of mud; moreover, they are the major reservoirs and occur in the bottom of Quan-4th member. The sandbars of the subaqueous distributary channels have higher mud content, and serve as the poorer reservoirs, and mainly occur in the top of Quan-4th member.

Size-dependent responses of zooplankton to submerged macrophyte restoration in a subtropical shallow lake

To explore the size-dependent responses of zooplankton to submerged macrophyte restoration, we collected macrophyte, zooplankton and water quality samples seasonally from a subtropical shallow lake from 2010 to 2012. Special attention was given to changes in rotifers and crustaceans （cladocerans and copepods）. The rotifers were grouped into three size classes （〈200 μm, 200μm-400μm, 〉400 μm） to explore their size-related responses to macrophyte restoration. The results showed that during the restoration, the annual mean biomass and macrophyte coverage increased significantly from 0 to 637 g/m2 and 0 to 27%, respectively. In response, the density and biomass of crustaceans and the crustacean-to-rotifer ratio increased significantly, while the rotifer density decreased significantly. Moreover, rotifers showed significant size- dependent responses to macrophyte restoration. Specially, rotifers 〈400 ~tm were significantly suppressed, while those≥400 μm were significantly encouraged. Overall, the population of large-sized zooplankton tended to boom, while that of small rotifers was inhibited during macrophyte restoration. Redundancy analysis （RDA） revealed positive correlations between macrophytes and crustaceans, rotifers and COD or Chl-a, but negative correlations between macrophytes and COD or Chl-a, and between crustaceans and Chl-a. Moreover, the results indicate that increased predation on phytoplankton by large-sized zooplankton might be an important mechanism for macrophyte restoration during development of aquatic ecosystems, and that this mechanism played a very important role in promoting the formation of a clear-water state in subtropical shallow lakes.

Effects of main range and strength factors on change of COD in a shallow lake

A model involving the relationship between non conservative matter (COD) and main range factors(loading, water stage) and strength factor (temperature) in a shallow lake has been established on the basis of less change of water stage area curve in certain extent, broader distribution in pollution sources and more homogeneous in quantity of heat. The effects of COD inflow and /or outflow, and hydro meterological factors upon COD content in Lake Taihu were calculated and simulated under the actual situation of the loadings and regimen. The results simulated by using the model are in better agreement with the observed field data. The error of the model was also discussed.

Hydroacoustic estimates of fish biomass and spatial distributions in shallow lakes

We conducted acoustical surveys with a horizontal beam transducer to detect fish and with a vertical beam transducer to detect depth and macrophytes in two typical shallow lakes along the middle and lower reaches of the Changjiang(Yangtze) River in November 2013. Both lakes are subject to active fish management with annual stocking and removal of large fish. The purpose of the study was to compare hydroacoustic horizontal beam estimates with fish landings. The preliminary results show that the fish distribution patterns dif fered in the two lakes and were af fected by water depth and macrophyte coverage. The hydroacoustically estimated fish biomass matched the commercial catch very well in Niushan Lake, but it was two times higher in Kuilei Lake. However, acoustic estimates included all fish, whereas the catch included only fish >45 cm(smaller ones were released). We were unable to determine the proper regression between acoustic target strength and fish length for the dominant fish species in the two lakes.

Evaluation of shallow groundwater discharge fluxes and nutrient fluxes in the west of Qinghai Lake using radium isotopes

We collected 14 samples and 9 samples for surface water in Quan bay and the north bay of Qinglai Lake respectively,as well as 11 samples for groundwater and 3 samples for river water.First the water samples were filtered through a

Response of rotifer community to environmental changes in five shallow lakes in the middle reach of Changjiang River, China

We evaluated the response of a rotifer community to environmental changes in five shallow lakes in the middle reach of the Changjiang （Yangtze） River in summer and autumn 2010. These five lakes differed in trophic status and rotifer community structure. Twenty-nine rotifer species were collected, of which Keratella cochlearis, Polyarthra dolichoptera, and Trichocerca elongate were dominant. The mean density, Shannon-Wiener diversity, and equitability among the five lakes differed significantly （P〈0.05）. The mean rotifer density was positively correlated with trophic state. The diversity was higher in lakes with high macrophyte coverage. The composition of rotifer species was closely associated with the trophic gradient. Five environmental variables, Secchi depth, conductivity, TN, NHa-N, and TP, significantly affected the composition of rotifer species. Keratella quadrata, Brachionus calyciflorus, and B. forficula were more common in eutrophic conditions. Our results suggest that eutrophication has a significant influence on the rotifer community structure and highlight the potential for using rotifer community structure as an indicator of trophic status in subtropical lakes.

Trophic Status of Shallow Lakes of La Pampa (Argentina) and Its Relation with the Land Use in the Basin and Nutrient Internal Load

Phosphorus and nitrogen are essential nutrients for living organisms. Their concentration in the water of an aquatic ecosystem is one of the factors responsible for the trophic status of the lake and is related to the soils of the region and to the human activities carried out in their basins. These nutrients are also found in the bottom sediments, where they can either be retained or re-enter the water column. Since the information about the concentrations of nutrients in the water of some lakes of La Pampa (Argentina) is fragmentary, the aim of this study is to describe the trophic status of some shallow lakes of the semiarid center of Argentina and analyze its relation with the human activities in their basins, the concentrations of nutrients and organic matter and particle size distribution of sediments. To this end, we studied ten shallow lakes subjected to different anthropogenic influences (agriculture, agriculture and livestock and impacted by cities). All were hypertrophic and the concentrations of total phosphorus and total nitrogen were among the highest reported globally. Since some lakes had no fish, cladoceran grazing (top-down effect) led them have reduced concentrations of phytoplankton chlorophyll-a and high water transparency. This relativizes the use of these parameters to determine the trophic status. The sediments of seven of the studied lakes were predominated by fine sands, whereas three were predominated by silts. Nutrient and organic matter content were high, with higher concentrations in lakes with prevalence of fine particles. The reduced adsorption capacity of sediments, the resuspension by wind, the anthropogenic input and the accumulation favored by the arheic character of the basins would explain the high concentrations of nutrients in the water of these Pampean environments.

Cretaceous Sandbody Characters at Shallow-Water Lake Delta Front and the Sedimentary Dynamic Process Analysis in Songliao Basin,China

Based on the abundant information from drilling, cores, and logging, the influence of topography, size of rivers and lakes, climate changes and the lake level＇s fluctuation on the sandbodies at shallow-water delta front are systematically summarized and the sedimentary dynamic processes are analyzed. The interwell communication among the sandbodies and their planar distribution revealed from the hydrodynamic features of the development wells are integrated during the analysis. The fundamental requirements for the development of the shallow-water delta included flat topography and uniform subsiding rate. The delta plain was connected smoothly with the wide delta front and predelta, without the three-fold structure of topset, foreset, and bottomset as defined in the Gilbert Delta Model. Because of the weak fluvial effect and the lake energy is strong, the small and scattered shallow-water delta is destroyed by the scouring-backwashing, coastal current, and lake wave, resulting in the coastal sheet deposition. As the fluvial effect became stronger and the lake energy became weaker, the shape of the shallow-water deltas transferred from sheets to lumps and then branches.

Emergent Macrophytes Alter the Sediment Composition in a Small, Shallow Subtropical Lake: Implications for Methane Emission

Aquatic macrophytes in shallow lakes emit high levels of methane. We hypothesize that the presence of emergent aquatic macrophytes in an artificial shallow lake promotes important input of autochthonous organic matter (OM) in sediment and higher levels of methane emission via bubbles. Samplings were performed at three sites in a small, shallow subtropical lake: (1) one station in the limnetic region and (2) - (3) two stations in the littoral region ((2) inside and (3) outside aquatic macrophyte stands). A higher concentration of OM was observed at the macrophyte station, and within this site, a higher methane concentration was observed in the sediment. These results could explain the methane ebullition values at macrophyte sites. At the macrophyte station, methane emission via bubbles contributed 17% to 56% of the total methane emission;however, at the other stations, its contribution via bubbles, was lower than 1%. This research confirmed the importance of emergent macrophytes at Polegar Lake as a source of OM in sediment and methane emission via bubbles. Further, we could confirm the positive effects of temperature on methane emission, mainly by bubbles.

Comparative study of epiphytic algal communities on Typha latifolia L.and Phragmites australis(Cav.)Trin.ex Steud in the shallow Gala Lake(European Part of Turkey)

The aim of this study was to determine the species composition, biodiversity and, relative abundance of epiphytic algae and their relationship with environmental variables on Typha latifolia and Phragmites australis at Lake Gala(National Park). Epiphytic algae were gathered monthly by collecting aquatic plants between March 2014 and November 2014. In the epiphytic flora were a total of 133 taxa were identified, 107 taxa were identified on T. latifolia and 96 were discovered on P. australis. While the mean species richness, species diversity and evenness values of the algae identified on T. latifolia were 46, 1.85 and 0.51 respectively, these values were respectively 43, 1.51 and 0.43 on P. australis. While diatoms were generally dominant, other dominant groups in the epiphytic flora included green algae and blue-green algae. The algae that had the highest relative biovolume on T. latifolia were Spirogyra affinis, Oscillatoria sancta and Gomphonema acuminatum, while the algae that had the highest relative biovolume on P. australis were E pithemia adnata, Oscillatoria sancta and R hopalodia gibba. Results show that species composition of epiphytic algae was different, but diversity values were similar on all the macrophytes. The hydrological pulse is one of the most important factors determining the physical and chemical environment of the epiphytic algal community. It was found that some environmental factors were highly eff ective on community distribution in the epiphyton. Additionally, it was observed that some epiphytic algae species had a substrate preference between T. latifolia and P. australis.

Characterizing Constituents of Sediment Phosphorus Fractionation in a Freshwater Shallow Lake System

This study aimed to characterize constituents of phosphorus （P） fractionation as wel as reciprocities among factors in sediments of a freshwater shal ow lake. [Method] Surface sediment was discretely sampled at 24 sites through Van Veen grabs. Based on a modified sequential extraction scheme, P fractionation was determined as Fe/Al bound P （Fe/Al-P）, Ca bound P （Ca-P）, solute and re-ductive P （S/R-P） and organic P （OP）. Curve estimation and Pearson product-mo-ment correlation were employed for statistical analysis. [Result] Total P （TP） content ranged from 443 to 774 mg/kg. Inorganic P （IP） was the major component of TP, of which Ca-P was dominated with an average of 51%±9.7%. Average contents of P fractionation were in the fol owing order： Ca-P（51%） 〉 OP（29%） 〉 S/R-P（8%） 〉Fe/Al-P（7%）. The molar ratio of Fe to P was 11 - 20, close to the threshold value of P leaching. [Conclusion] In freshwater shal ow lakes, IP and Ca-P were prone to be relatively high, whereas Fe/Al-P was low compared with deep lakes. Occurrence of spatial y monotonic gradient indicated the primary causation of anthropogenic sources. Imminent sediment P liberation was also expected. Close associations a-mong TP, Fe/Al-P and Ca-P, implying that anthropogenic P was mainly bound to metals in particulates. Significant correlations of TOC and P fractionation highlighted endogenous mechanism and authigenic origin in sediments.

Spatio-temporal dynamics of cyanobacterial abundance and toxicity in a Mediterranean hypereutrophic lake

The Mediterranean basin is considered one of the most vulnerable areas in the world under the impacts of global warming and changes in precipitation patterns.Oubeira,a shallow and polymictic freshwater lake located in northeastern Algeria(36°50′N,08°23′E),has recently experienced a significant proliferation of harmful cyanobacteria resulting in the generation of toxins.We carried out this study in order to understand the succession patterns of dominant cyanobacteria and cyanotoxin production and the factors driving this in Oubeira Lake.A total of 26 cyanobacterial genera were identified,and among them Microcystis and Planktothrix accounted for more than 60%of the overall cell abundance.The summer/fall period was dominated by Microcystis,Planktothrix,and in lesser extend by Cylindrospermum,Cylindrospermopsis.During the fall/winter transition,Dolichospermum,Pseudanabaena,and Aphanizomenon were the dominant genera.Statistically,the bloom-forming cyanobacteria showed significant differences between months but not between stations.Intracellular microcystins(MC-LR)was detected in all collected samples(0.62-and 19.14-μg MC-LR equivalent/L),but appeared in high concentrations throughout the period of dominance of Microcystis and Planktothrix.Microcystis was more sensitive to nutrients than to temperature.Planktothrix was more dependent on temperature than on nutrients,which explains their coexistence during summer-fall period.However,both genera are positively correlated with MC-LR and would probably be the main producers of microcystins.Pseudanabaena,Dolichospermum,and Aphanizomenon co-occurred at the end of Planktothrix dominance period(December).Aphanizomenon and Pseudanabaena were correlated negatively with temperature and positively with water conductivity.Dolichospermum showed a strong positive correlation with MC-LR.Oubeira Lake,could serve as a model of how cyanobacteria blooms may develop in lakes within Mediterranean climates.

河控浅水三角洲前缘树枝状沙坝沉积构型与形成机理

河控浅水三角洲前缘砂体可分为分流沙坝型和指状沙坝型2类河-坝组合类型,前人多关注扇状的分流沙坝型与鸟足状的指状沙坝型的前缘砂体,而对多个指状沙坝组成的树枝状沙坝关注不足,其沉积构型与形成机理尚不清楚。以鄱阳湖日帽洲三角洲为例,综合卫星地图、探地雷达、浅钻孔、沉积数值模拟数据,揭示了河控浅水三角洲前缘树枝状沙坝的沉积构型与形成机理。研究认为,树枝状沙坝是由多个相互分叉、交汇的指状沙坝拼接而成,呈现“河在坝上走”的河-坝组合关系,其间发育分流间湾。根据规模差异,树枝状沙坝内的分流河道可分为主支分流河道与侧支分流河道,主支分流河道的宽度大、数量少,多发育于近源端并延伸至沙坝末端,分布于沙坝中部;侧支分流河道的宽度小、数量多,多分布于前缘两侧与末端。树枝状沙坝的形成与细粒、黏性、高排量河流供给相关,细粒与黏性沉积物促进了稳定天然堤的加积与指状沙坝的形成,高排量导致了分流河道的分流与决口,从而形成树枝状的指状沙坝。河控浅水三角洲前缘树枝状沙坝储集层的侧向连通性较差,优势储集层位于指状沙坝中部,为分流河道砂体与近岸河口坝砂体。

鄱阳湖湿地碟形湖-河流水稳定同位素变化特征及其指示意义

为深入认识鄱阳湖湿地区域水循环过程,于2019年112月在鄱阳湖国家级自然保护区对降水、河流水、主要碟形湖水进行系统采集,综合分析碟形湖-河流水稳定同位素的动态变化特征及其指示意义。结果表明,鄱阳湖湿地修河和赣江的同位素组成具有明显的季节性变化规律,4月河水同位素最为富集,57月逐渐贫化,之后呈现出不断富集的变化趋势,整体上与降水同位素的时间变化特性相似。在空间分布上,各段河水的同位素组成均具有相对稳定的沿程分布特征,赣江在修河汇入点上、下游的同位素特性在大多数月份没有呈现出明显变化。碟形湖水同位素的年内变化范围比河水大,并且相对富集。主要碟形湖水的δ2 H-δ18 O关系接近当地大气降水线,具有更小的蒸发线斜率以及系统性偏离的特征,反映碟形湖主要受到当地降水补给,经历了一定程度的蒸发作用。基于指数模型方法估算修河和赣江水体的平均滞留时间(mean residence time,MRT)分别为1.54和0.81年,赣江较短的MRT表明鄱阳湖流域具有不同水体组分相互快速转化的水力条件,修河上游柘林水库的调蓄作用导致其MRT明显大于赣江。通过假定碟形湖水的蒸发过程遵循瑞利分馏模型,全年的同位素监测结果揭示蚌湖、沙湖、大湖池的年平均蒸发损失量分别为15.5%、15.0%、14.1%,不同碟形湖之间蒸发程度的差异可能与地形、植被和水动力条件等因素的综合影响有关。

长江中下游典型浅水湖泊表层水体微塑料时空分布特征——以湖北保安湖为例

以湖北保安湖为研究对象,分别于2021年4、7、10月和2022年1月采集表层水样,测定水体中微塑料丰度、粒径、形状、颜色和类型,探究浅水型湖泊表层水体中微塑料的时空分布特征及其影响因素。结果表明,保安湖表层水体微塑料的年平均丰度为(16.20±2.23)items/L。微塑料丰度呈现明显的季节性差异,其中夏季(采样时间7月)平均丰度最低,为(1.40±0.09)items/L。在所有微塑料颗粒中,粒径0.064~1 mm占比最大,为82.57%;黑色和无色微塑料占主导地位,占比分别为36.16%和21.31%;纤维状微塑料分布最广泛,占比达40.01%;聚乙烯(PE)和低密度聚乙烯(LDPE)是最主要的微塑料类型,两者之和占比达46.05%,其次为聚苯乙烯(PS,占比17.2%)、聚对苯二甲酸乙二醇酯(PET,占比8.33%)和聚乙酸乙酯(PVAC,占比8.31%)。统计分析表明,微塑料丰度与湖水水质无显著相关关系。该研究揭示了长江中下游地区典型浅水湖泊微塑料分布现状,为评估类似湖泊微塑料潜在污染风险提供了科学依据。