Anthropogenic Impacts on the Distribution and Biodiversity of Benthic Macroinvertebrates and Water Quality of the Boufekrane River, Meknes, Morocco

The area of the city of Meknes (Morocco) undergoes anthropic pressure, which acts mainly on the rivers. River water is used, without preliminary treatment, for farm irrigation. A study of the impacts of anthropogenic activities on the distribution and biodiversity of benthic macroinvertebrates and water quality of the Boufekrane River (Meknes) was conducted. Four pristine stations from the upstream and two stations at the downstream receiving anthropogenic impacts were selected along the River. For 12 consecutive months (from January to December 2010), based on the SEQ-V.2 scoring system, water quality index classes, the upstream stations recorded significantly higher biological monitoring scores and better water quality indices than those of the downstream. Four variables are involved actively in the individualization of the physico-chemical environment: COD, dissolved oxygen, TSS and temperature. The total number of macrobenthic taxa and their overall richness indices and diversity indices were significantly higher at the upstream stations than at the downstream stations. The relationships between the physicochemical and the macrobenthic data were investigated by biotypology analysis (PCA and FCA) and Pearson correlation analysis. The analyses showed that the richness and diversity indices were generally influenced by the total suspended solids, chemical oxygen demand and the electric conductivity of the river water. This study also highlighted the impacts of anthropogenic activities on the distribution and species diversity of macrobenthic invertebrate. Some sensitive (Trichoptera and Ephemeroptera) and resistant species (Oligochaeta such as Tubifex sp.) are identified as potential bioindicators of clean and polluted river ecosystems, respectively, in Morocco rivers. The data obtained in this study supported the use of the bioindicator concept (Innovative Biotechniques for controlling water quality) for North Africa rivers because it is more efficient than conventional methods.

Spatial and seasonal pattern of macrozoobenthic assemblages and the congruence in water quality bioassessment using different taxa in artificial Mingzhu Lake in Shanghai

The spatial and seasonal pattern of macrozoobenthic structure and its relationship with environmental factors were studied from July 2006 to April 2008 in Mingzhu Lake,Chongming Island,Shanghai at the Changjiang River mouth.The congruences in water quality bioassessment based on diversity and biotic indices and using different taxonomic categories were also explored to find the best assessment method of water quality for the lake.All major structural characteristics of macrozoobenthic community,including species composition,abundance,biomass and four biomass-based diversity indices(Shannon's diversity,Simpson's diversity,Pielou's evenness and Simpson's evenness index) fluctuated significantly in season but in space.The above four abundance-based diversity indices plus abundance-based Margalef's richness index did not display significant spatial variations;and significant seasonal differences were found in three indices only.Water temperature was the key environmental factor responsible for macrozoobenthic spatio-temporal distribution patterns.Water quality assessed by Shannon's index(H_a') and biological pollution index(BPI) rather than the other four biotic indices were consistent with those by trophic state index(TSI).Results from chironomids and oligochaetes did not always agree to those from the whole community when H_a' or Hilsenhoff biotic index was applied to bioassessment.Therefore,combining multiple indices and avoiding a single taxonomic category to assess water quality are strongly recommended and in Mingzhu Lake using a mixture of H_a' and BPI will ensure the most effective investigation of water quality.Our results also show that the main structural characteristics of macrozoobenthic communities in the small lake may display consistent spatial patterns.

Influence of Water Quality on the Variation Patterns of the Communities of Benthic Macroinvertebrates in the Lakes of the Central Highlands of Peru

The influence of water quality on the variation patters of benthic macroin-vertebrate communities in the lakes in the central highlands of Peru was eva-luated. Samples of water and sediments were collected in 23 different sam-pling sites last 2017. The physiochemical variables of water quality deter-mined on site were: DO, TDS, EC, temperature and pH. The results obtained revealed that the physiochemical indicators are within the environmental quality standards for water, except COD and BOD5. Regarding the benthic macroinvertebrates, four phyla were identified wherein the most common is the phylum Arthropoda having the abundance and richness of taxa. The PCA reduced the variables to a few significant components that caused variation in water quality between lakes. The cluster analysis in relation to the relative abundance of benthic macroinvertibrates grouped the 22 sampling sites into three groups with the similar characteristics. The PCoA analysis of the ben-thic macroinvertebrate communities showed a clear separation of sites. The SIMPER analysis at the family-level showed the distribution of the most common species. Therefore, at a significance level of 0.01 it demonstrates that there are significant differences between the number of species and abun-dance of the areas that were evaluated.

Integrated assessment of river health based on water quality, aquatic life and physical habitat

The health conditions of Liao River were assessed using 25 sampling sites in April 2005, with water quality index, biotic index and physical habitat quality index. Based on the method of cluster analysis （CA） for water quality indices, it revealed that heavily polluted sites of Liao River are located at estuary and mainstream. The aquatic species surveyed were attached algae and benthic invertebrates. The result showed that the diversity and biomass of attached algae and benthic index of biotic integrity （B-IBI） were degrading as the chemical and physical quality of water bodies deteriorating. Physiochemical parameters, BODs, CODcr, TN, TP, NH3-N, DO, petroleum hydrocarbon and conductivity, were statistically analyzed with principal component analysis and correlation analysis. The statistical results were incorporated into the integrated assessing water quality index, combining fecal coliform count, attached algae diversity, B-IBI and physical habitat quality score. A comprehensive integrated assessing system of fiver ecological health was established. Based on the systimetic assessment, the assessed sites are categorized into 9 ＂healthy＂ and ＂sub-healthy＂ sites and 8 ＂sub-sick＂ and ＂sick＂ sites.

Integrated Assessment of the Ecological Status of Bulgarian Lowland and Semi-Mountain Natural Lakes

This work focuses on an integrated approach for lake ecological status assessment, elaborated according to the requirements of the European Water Framework Directive (WFD). Data from five lowland and semi-mountain lakes in Bulgaria (Southeast Europe) collected from two years (2011-2012) form the basis for an integrated assessment and the definition of reference conditions. Several metrics were applied in combination, to classify lakes into five ecological status classes. Assemblages of aquatic organisms: phytoplankton, macrophytes and benthic macroinvertebrates, together with 11 supporting physico-chemical parameters were studied. The assessed unique conditions suggested that reference conditions of Bulgarian lakes have natural variability. This first baseline study illustrated specific cases within the lake types that should be assessed in details before providing standardized classification systems in compliance with the requirements of WFD.

Bioassessment of the Rio Grande Upstream and Downstream of Los Alamos National Laboratory,New Mexico, USA

Benthic macroinvertebrates (aquatic insects) were collected from the Rio Grande upstream and downstream of Los Alamos Canyon (LAC), a major drainage that crosses Los Alamos National Laboratory (LANL) lands in northern New Mexico, USA. LAC contains legacy waste, including radionuclides and polychlorinated biphenyls, and occasionally discharges storm water and snowmelt flows to the Rio Grande. The Rio Grande is the major waterway that flows southward across the state. In 2009, rock baskets were placed in waters 61- to 76-cm-deep within each reach (five per reach), and, after approximately 6 weeks of colonization, the rock baskets were retrieved. All samples were sorted completely and organisms were identified to the lowest possible taxonomic level. Both reaches in 2009 were dominated by the collector filtering net-spinning caddisfly, Hydropsyche occidentalis. In 2011, benthic macroinvertebrates were collected using D kick nets from shallow riffle locations (15- to 31-cm depth) from each reach (six per reach). These samples were collected after post- (Las Conchas) fire flooding events moved sediment and ash through the two study areas—the downstream reach, however, was affected by higher flows and greater number of flooding events than those affecting the upstream reach. Each kick net sample consisted of ten 1-m (kick) samples. The 10 subsamples were composited and organisms were picked from randomly selected cells in a sorting pan until 500 organisms had been identified to the lowest possible taxonomic level. Both reaches in 2011 were dominated by the collector-gathering mayfly, Baetis tricaudatus. A bioassessment of the downstream reach compared with the upstream (reference) reach was conducted by scoring 10 metrics related to the structure and function of the benthic macroinvertebrate community. While 2009 ranked at the highest level (nonimpaired), 2011 ranked a level lower (slightly impaired). The slightly lower bioassessment score of the downstream reach in 2011 may be a result of flooding impacts following the Las Conchas fire rather than of LANL operations. Overall, based on the similarity of benthic macroinvertebrate metrics between reaches and the composition of benthic macroinvertebrates favoring pollution intolerant taxa, LANL influences, if any, via the LAC system to the Rio Grande are not significantly impacting water quality of the Rio Grande.

仁怀市主要河流春季大型底栖动物群落结构及其水质评价

底栖动物是水域生态系统不可或缺的组成部分,亦是水环境状况的重要指示类群。为探究仁怀市主要河流大型底栖动物的群落结构和水质状况,我们于2023年春季对赤水河仁怀段干流、8条主要支流及其附属水库的大型底栖动物群落进行了调查。结果发现:此次考察共采集到大型底栖动物93种,隶属于4门7纲18目58科,其中,软体动物17种(18.28%);环节动物9种(9.68%);水生昆虫65种(69.89%);甲壳动物和扁形动物各1种(均占1.08%)。优势种为多足摇蚊属一种(Polypedilum sp.)、河蚬(Corbicula fluminea)、摇蚊属一种(Chironomus sp.)与长跗摇蚊属一种(Tanytarsus sp.)。利用生物多样性和底栖动物分类评价指数对该市主要河流进行水质生物学评价,结果显示:Shannon-Wiener指数与Margalef指数评级偏差,Pielou指数评级偏优,而生物学污染性指数和生物指数评级一致,指示仁怀市主要河流水质整体上存在一定程度的退化。

黄浦江水生态系统变化趋势分析与改善策略

文章基于2013年—2014年和2021年的黄浦江水质、水生态调查数据以及通过问卷获得的公众相关生态感知数据,分析对比差异和变化趋势,探究了这一时期黄浦江干流水生态系统相关指标的变化特征和影响因素,并提出了改善策略。研究结果表明:2014年以来,黄浦江干流水质改善明显,大型底栖无脊椎动物和鱼类群落得到一定程度的恢复,公众对于黄浦江生态现状的满意程度也比先前有一定提升,但是黄浦江干流各河段生态由于区位因素、沿线产业模式等原因在这一时期的变化又各有特点,也面临着不同状况和问题。研究为后续开展黄浦江水生态系统治理和恢复工作提供了一定指导依据。

长江中下游浅水湖泊底栖动物评价指数筛选及其应用研究

以长江中下游13个浅水湖泊周年季节性湖沼学调查所获得的水质生物评价数据为基础,通过指数与环境因子的相关分析,指数值的分布范围分析,以及判别能力分析对其进行筛选,确定了Shannon-Wiener指数、Margalef指数、BI指数3个对水质判别较为敏感的底栖动物生物指数,并采用分位数法确定其水质评价分级标准。应用此3种评价指数对长江中下游13个湖泊进行水质判别,3个指数评价的结果基本吻合,且生物学评价结果和化学评价结果较为接近,属中度污染以上的湖泊,其营养状态均达到了富营养化水平。该评价指数及其评价标准适用于评价长江中下游地区浅水型湖泊的水质状况。

Water quality impacts of small-scale hydromodification in an urban stream in Connecticut, USA

Introduction:Construction activities in and along urban streams increase the sediment input into surface waters,causing an overall decline in water quality and aquatic ecosystems.In this case study,we investigate the water quality impacts of local hydromodification in an urban stream(discharge 0.4 m^(3)/s).At the site of interest,workers removed a stream crossing consisting of an embankment with culverts and replaced it with a small bridge(single span of 25 m)in an effort to improve flow capacity.Methods:Water samples were taken at four sites along the North Branch Park River in Connecticut,Northeastern United States.Turbidity and dissolved oxygen(DO)were measured in situ,and nitrate and total phosphorus(TP)were measured in the laboratory.Benthic macroinvertebrate samples were also collected and analyzed for taxon richness and Shannon-Weaver species diversity.Data were compared between upstream and downstream sites and before,during,and after hydromodification.We used one-way ANOVA combined with the post hoc Turkey test to derive statistical significance.Results:During construction,turbidity increased temporarily by 60.9%[from 2.48 Nephelometric Turbidity Units(NTU)over ambient to 4.00 NTU].Once construction was completed,DO increased locally from 11.0 to 13.0 mg/L.Benthic macroinvertebrate taxon richness and species diversity declined by 61.6 and 32.6%respectively,with no recovery observed in the year following construction.Water quality was only affected within 50 m downstream.Nitrate and TP concentrations were unaffected.Conclusions:Small-scale hydromodification temporarily increased the turbidity as a result of increased sediment input,approaching the maximum level for clean water(5 NTU).Benthic macroinvertebrate communities declined in the immediate downstream vicinity of construction but are expected to recover soon given that turbidity recovered to pre-construction levels,and DO increased.These outcomes emphasize that environmental assessment is important not only for large-scale hydromodification but also for smaller scale stream modifications.

湖荡区大型底栖无脊椎动物评价方法适用性探讨--以长三角一体化示范区为例

开展了青浦区西部地区大型底栖无脊椎动物调查,基于底栖生物完整性指数(benthic index of biotic integrity,B-IBI)评价体系,评价了区域水生态健康状况,分析了B-IBI指数与水质指标及相关指数的关系,探讨了B-IBI指数在湖荡地区的适用性.结果表明:研究区域水生态健康状况总体良好,健康及亚健康样点占比67.7%,湖泊及湖荡区域的B-IBI指数多优于河流;B-IBI指数对水体有机污染、富营养化有较好的指示作用;各评价指数之间具有显著相关性,但B-IBI指数与丰富度指数、多样性指数评价结果有所差异;B-IBI指数在湖荡区水生态评价中具有很好的适用性.

太湖水质评价中底栖动物综合生物指数的筛选及生物基准的确立

对太湖8个区域共60样点进行底栖大型无脊椎动物采样,共获得底栖动物24种,其中软体动物14种,节肢动物5种,甲壳动物5种。根据Hilsenhoff生物指数确定了15个相对清洁的样点和45个污染样点,然后进行21种生物指数的综合评估,结果表明,总分类单元数、（甲壳动物＋软体动物）分类单元数、%（甲壳动物＋软体动物）、%腹足纲、Goodnight-Whitley指数、Hilsenhoff生物指数和%直接收集者等7个底栖动物生物指数可以用作判别太湖水质的敏感生物指数。通过5,3,1记分法对6种生物指数统一量纲后,获得变化范围为7-35的综合生物指数,运用四分法划分了太湖水质判别的生物基准：7-14很差,15-21差,22-28一般,29-35好,并对60个样点进行重新记分,获得了太湖水质的基本生态分区现状,太湖的东南区属水质较好的区域,而西北区属水质较差的区域。该水质生物基准基本适合评价太湖不同区域的水质状况。

庐山地区底栖大型无脊椎动物耐污值与水质生物学评价

自 1996年至 1999年 ,对庐山自然保护区 2 2个采样点的底栖大型无脊椎动物进行了调查 .完成了庐山底栖大型无脊椎动物大多数科与部分属的耐污值核定工作 ,在Hilsenhoff(1988)与Lenat(1993)工作基础上 ,新增 73科的耐污值 .首次提出了蜚蠊目Blattodea、脉翅目Neuroptera、半翅目Hemiptera及鞘翅目Coleoptera水生类群的耐污值 .其它主要水生昆虫 11个目 ,凡在中国有分布记录或可能在中国及邻近地区有分布的科均收入并提出耐污值 .摇蚊科中国常见的 16属引用了Lenat(1994 )推荐的耐污值 ,增加了甲壳纲Crustacea、寡毛纲Oligochaeta、腹足纲Gastropoda、腮瓣纲Lamellibranchia、蛭纲Hirudinea、涡虫纲Turbellria与蜱螨纲Acarina水螨总科Hydrachnoidea等的耐污值 .利用上述耐污值系统 ,对 2 2个采样点中的 13个进行了连续水质生物监测 ,对其余 9个采样点水质进行了评估 .1996年 5月至1999年 9月期间 ,13个采样点水质由重污染至极清洁排序可分 6类 :如琴湖、东谷溪流、电站水库属重污染水体 ;天桥由轻污染至重污染 ;2级站、1级站、3级站由很清洁或清洁至一般 ;芦林湖、电站水库南支流很清洁 ;黄龙潭由很清洁至轻污染 ;三叠泉、第四纪冰川遗址、大月山水库为极清洁 .多数采样点 1996年 11月水质好于 5月份的水?

基于底栖动物完整性指数的洞庭湖典型断面的水质评价

2010年在枯水期、平水期、丰水期对洞庭湖的7个典型断面进行了大型底栖无脊椎动物采样,共获得底栖动物40种,其中节肢动物16种、软体动物18种,环节动物6种。根据Shannon-Wiener物种多样性指数确定了4个相对清洁的断面和3个污染断面,然后进行23种生物指数的综合评估,结果表明,(甲壳动物+软体动物)分类单元数、Shannon-Wiener物种多样性指数与Goodnight-Whitley指数3个底栖动物生物指数可以用作辨别洞庭湖典型断面水质的敏感生物指数。通过5、3、1记分法对3种生物指数统一量纲后,获得变化范围为3～15的综合生物指数,运用四分法划分出洞庭湖典型断面水质辨别的生物基准:3～6,差;7～9,一般;10～12,好;13～15,很好。据此对7个断面进行重新记分,获得了洞庭湖典型断面水质的基本分区现状:虞公庙、万子湖、目平湖3个断面的水质良好,而鹿角、坡头、南嘴及东洞庭湖4个断面的水质较差。该水质生物学基准基本适合评价洞庭湖典型断面的水质状况。

北江大型底栖无脊椎动物群落结构及水质的生物评价

对北江25个采样点的大型底栖无脊椎动物进行采样调查,并根据大型底栖无脊椎动物的群落结构特征对水质进行生物评价。研究中共采集到大型底栖无脊椎动物46属,分别隶属于15目31科,其中水生昆虫30属,占65.22%;软体动物8属,占17.39%;环节动物6属,占13.04%;甲壳动物2属,占4.35%。出现频率最高的3个种属分别为多足摇蚊属(Polypedilum)、巴蛭属(Barbronia)以及苏氏尾鳃蚓(Branchiurasowerbyi)。应用Shannon-Wiener多样性指数、Margalef多样性指数、Pielou均匀度指数、生物学污染指数BPI(biotic pollution index)、BI(biotic index)、FBI(family biotic index)、Goodnight-Whitley修正指数(GBI)7种生物指数对北江水质进行综合评价。结果表明:与20世纪80年代的评价结果相比,北江的大型底栖无脊椎动物在种类和数量等多方面均发生了较大的变化,生物多样性减少,耐污种所占比例增加,水质理化参数恶化;7种生物指数的评价结果存在一定的差异,部分指数之间存在较高的相关性,FBI指数和BPI指数的准确性和科学性更强,适用于北江水质的生物评价。在25个采样点中,6个采样点水质综合评价等级为较差或极差,16个采样点水质评价等级为一般,3个采样点水质等级为良好,整体水质属于一般的水平。人类活动对河流的水质状况造成了一定的影响。从水质生物学的角度衡量,北江水质整体呈现下降趋势。

苏州河水质和底栖动物群落1996～2006年的时空变化

分析评价了1996～2006年苏州河水质和底栖动物群落结构的时空变化。结果表明:苏州河环境综合整治工程并没有明显改变下游河段溶解氧低下的状况,底栖生态系统没有改善;苏州河中上游水生生态系统的退化,可能会抵消下游水质改善的效果。苏州河污染整治和水生生态修复的重点应当转移到上游地区。长期数据统计和分析不仅能解释苏州河多年离散的生物学数据,揭示大型底栖动物的长期时空变化规律及其与水质变化的对偶关系,还能指示苏州河修复的关键河段,可以成为河流水质和生态系统评价的有效方法。

适于北江水质生物评价的附着硅藻指数研究

采用主成分、层次聚类、箱型图和双向指示种分析(TWINSPAN)等方法,研究了15项附着硅藻指数在北江流域的适用性。在北江流域25个监测点中,共鉴定出附着硅藻2目6科30属98个种和亚种,相对丰度为5%以上的硅藻属有曲壳藻属(Achnanthes)、菱形藻属(Nitzschia)、舟形藻属(Navicula)和直链藻属(Melosira),分别为34.4%、18.1%、8.6%和7.3%。相对丰度为5%以上的硅藻种有极小曲壳藻(Achnanthes minutissima),极小曲丝藻(Achnanthidium minutissimum),克劳斯菱形藻(Nitzschia clausii)和可变直链藻(Melosira varians)。附着硅藻指数间,罗特营养指数(Rott Trophic Index,ROTT)和洛博指数(Lobo Index,LOBO)与其他指数相关性较弱,硅藻生物指数(Biological Diatom Index,IBD)和富营养污染硅藻指数(Diatom Eutrophication Pollution Index,EPI-D)呈极显著相关(r=0.915,P<0.01)。硅藻指数与水质指标的相关性分析表明,斯雷德切克指数(Sláde?ek Index,SLA)和LOBO与电导率(Cond)、溶解氧(DO)和总磷(TP)等10项水质指标间均无相关性,其他指数与某个或某几个水质指标有一定的相关性。对10项水质指标加权后进行层次聚类,结果表明阿图瓦-皮卡第硅藻指数(Artois-Picardy Diatom Index,IDAP)、特定污染敏感指数(Specific Polluosensitivity Index,IPS)、硅藻属指数(Generic Diatom Index,IDG)和IBD与水质分类结果较一致。利用TWINSPAN对样点和硅藻群落进行分类后绘制箱型图,结果表明,IBD对样点水质的变化最为敏感。结果表明,IBD是适合北江流域水质评价的硅藻指数。

北运河水系底栖动物群落结构与水环境质量评价

为全面了解北运河水系的底栖动物群落结构和水环境质量,于2015年5月对北运河水系33个样点的底栖动物和水体理化性质进行了调查,分别采用综合水质标识指数法和底栖动物BI指数法对北运河水系进行水质评价,并通过Kolmogorov-Smirnov检验判断正态性,用Pearson相关分析方法对两种评价结果进行比较和分析.结果表明:北运河水系共采集到底栖动物23种,隶属于3门4纲6目11科11属,以水生昆虫和软体动物为主,整个水系底栖动物群落结构单一;底栖动物BI指数法的评价结果显示,72%的采样点水质为中污染(Ⅳ)或重污染(Ⅴ);综合水质标识指数法的评价结果显示,超过57%的采样点水质为Ⅳ类及以下;根据K-S检验,两组评价得分均符合正态分布;Pearson相关分析显示两种评价结果呈显著正相关.两种评价结果总体上呈现出相同的趋势,均显示北运河水系整体水质状况较差,干流水质状况优于支流,上游水质状况优于下游,温榆河上游、坝河下游、通惠河上游和凉水河的水质状况较差,温榆河源头和坝河上游的水质状况较好.两种评价结果在个别点位存在一定差异,具体表现为基于水体理化因子的评价结果稍优于水质生物评价结果,造成这种差异的原因是两种评价方法在时空尺度上存在差异.针对城市化水平较高、人类活动干扰较强的北运河水系,同时采用这两种评价方法有助于全面了解其复杂的水环境质量.

硅藻指数在嫩江支流甘河的适用性评估

为了筛选出适用于甘河水生态评价的硅藻指数,合理评价甘河水生态健康状况,2018年8月在嫩江支流甘河调查了19个点位的着生硅藻群落结构和水环境特征.应用21种硅藻指数对甘河水生态健康状况进行评价,采用箱体图法分析了所选硅藻指数的适用性,使用Spearman相关分析研究了硅藻指数与环境因子的相关性,最后应用多元线性回归方法分析了不同因素对硅藻指数在甘河评价正确率的影响.结果表明:①所选硅藻指数中,IBD(biological diatom index,硅藻生物指数)、EPI-D(diatom eutrophication pollution index,富营养污染硅藻指数)和IPS(specific pollution sensitivity index,特定污染敏感指数)的评价结果区分度最好,最适用于甘河水生态健康状况评价.②甘河丰水期水生态健康状况总体较好,约70%的点位水生态健康状况为健康、较好和一般,约30%的点位水生态健康状况为较差和极差,极差的点位全部位于甘河下游区域.③硅藻指数与COD Cr的相关性对硅藻指数评价正确率有显著影响(P<0.01),硅藻指数与COD Cr相关性越强,评价的正确率越高;物种覆盖度对硅藻指数评价的正确率也有影响,但不显著,各点位最小物种覆盖度高于65%时,物种覆盖度对藻指数评价的正确率影响较为明显.研究表明,硅藻指数可以有效地评价水生态健康状况,但硅藻指数与环境因子之间的相关性等因素会影响评价的正确率,因此选择合适的硅藻指数进行研究区域的水生态健康状况评价尤为重要.

昆承湖大型底栖动物时空分布及对环境修复的指示性

2015年对常熟市昆承湖的大型底栖动物进行了时空分布调查,开展了水质生物学评价与环境影响因子分析,并基于底栖动物分布特征对昆承湖2006—2012年环境修复工程效果进行初步评估。结果表明:4次调查共采集底栖动物12科22种,优势物种多为耐污型;底栖动物年均密度为38.3 ind/m^2,各季节密度分布存在差异,但均以摇蚊幼虫类密度占优,其次为寡毛类和软体动物,底栖动物年均生物量为24.54 g/m^2,主要为软体动物所贡献;底栖动物Shannon-Wiener多样性指数值(H')、Margalef多样性指数值(D)、Pielou均匀度指数值(J)和BI指数值表明,昆承湖总体处于中度污染状态;不同湖区因污染程度等环境因素不同,底栖动物物种、密度与生物量分布存在差异,典范对应分析表明水体DO、浊度、TN、TP等水质因子以及底泥TN、总有机物等是影响底栖动物分布的主要环境因子;昆承湖实施封闭湖泊口门、深度清淤等环境修复措施后,水质总体得到改善,但湖泊水深增大、基底形态单一以及水生植物分布少等因素也影响了湖泊底栖动物密度与种群分布。