Temporal and spatial changes in macrozoobenthos diversity in Poyang Lake Basin,China

Poyang Lake plays a significant role in maintaining and replenishing the macrozoobenthos biodiversity in the middle Yangtze River. However, due to human activities and natural factors, the habitat of Poyang Lake has been seriously degraded, resulting in a decline in macrozoobenthos biodiversity. Here, we analyzed the effect of human activity and environmental elements change on the diversity of macrozoobenthos based on a systematic investigation of Poyang Lake Basin in 2016–2017. The current species richness, density, and biomass of macrozoobenthos were lower than those in the historical period. At the same time, the community structure of the macrozoobenthos assemblage exhibits significant temporal and spatial differences. In addition, the spatial turnover component was the main contribution to beta diversity, which indicated that a number of protected areas would be necessary to conserve the biodiversity of macrozoobenthos. Water depth, dissolved oxygen, water velocity, and chlorophyll‐a were significantly correlated with macrozoobenthos distributions and assemblage structure based on RDA. These results indicated that human activities have seriously destroyed the macrozoobenthos habitat and led to the decline in macrozoobenthos diversity. Therefore, habitat restoration and the conservation of macrozoobenthos have become urgent in Poyang Lake Basin, and an integrated management plan should be developed and effectively implemented.     

椒江口化工园区及其邻近区域潮间带大型底栖动物秋冬季分布特征

为了解椒江口化工园区及其邻近区域潮间带大型底栖动物分布特征,评价工厂排污对河口潮间带大型底栖动物生态的影响范围及程度,在椒江口共设置6条潮间带采样断面,于2007年10月和2008年1月进行了大型底栖动物野外调查.研究结果如下:(1) 秋冬两季共采集到大型底栖动物75种,其中秋季64种,冬季29种;(2) 物种数呈现河口外断面高于河口内断面的变化趋势;(3) 在各断面软相基质站位,化工园区及其邻近区域的大型底栖动物物种组成差异较大,栖息密度和生物量差异不显著;(4) 与国内其他河口近几年的调查数据相比,椒江口潮间带发现的大型底栖动物种数较高,且存在开敞型河口潮间带大型底栖动物种数大于内湾河口潮间带的现象.     

海洋大型底栖动物对海岛开发的生态响应——以宁波大榭岛为例

以开发时间长,产业密集的国家海岛开发试点大榭岛为例分析、评价了海岛开发的潮间带和近岸海域大型底栖动物生态响应。通过对大榭岛岩礁相、泥沙相潮间带以及近岸海域大型底栖动物的物种组成、群落结构和数量分布的分析,同时与该岛周围开发程度较弱的几大海岛的类似生境中大型底栖动物状况进行比较。结果发现:(1)大榭岛岩相潮间带断面牡蛎科(Ostre idae)和藤壶科(Balan idae)等科的物种栖息密度较高,生物多样性较低;(2)泥沙相潮间带底栖动物状况与其他海岛差别不显著;(3)大榭岛近岸海域底栖动物种数少于其他海岛近岸海域,且前者不倒翁虫(Sternaspis scutata)和小头虫(Capitellacapitata)等多毛类物种栖息密度较高,生物多样性较低,群落结构与其他区域相差较大;(4)环境质量的生物评价结果显示,大榭岛近岸海域扰动程度高于其他海岛近岸海域。此外,从海岛开发的规划与功能定位、工程设计与施工工艺、相关人员意识形态三方面提出了一些保护和恢复海洋生物多样性的对策。     

Macrozoobenthos of Lake Verevi

An overview on studies of macrozoobenthos in the small, hard-water, stratified and hypertrophic Lake Verevi (South-Eastern Estonia) is given. The list of macroinvertebrates comprises at least 105 taxa. In the open water habitats, the biomass and abundance of macrozoobenthos (except the phantom midge Chaoborus flavicans) was rather constant beginning from the epilimnion up to the upper hypolimnion (depth 2–4 m), but very low in the lower hypolimnion (depth 6 m), which was inhabited mainly by Chaoborus. Comparison with long-term reference data from other Estonian lakes, belonging to similar limnological types, indicated that the total biomass and abundance (without Chaoborus) in the profundal of Verevi were very low.     

胶州湾西北部潮滩湿地大型底栖动物功能群

2009年2、5、8和11月进行了7个断面35个站位的大型底栖动物调查,选取高潮区(A)、中潮区(B、C、D)和低潮区(E)研究了胶州湾西北部潮滩湿地大型底栖动物功能群组成及其时空变化.调查共发现大型底栖动物71种,主要种类为软体动物(31种)、环节动物(20种)和节肢动物(14种).潮区A、B、C、D、E物种数分别为26、33、35、38、31.依据食性将主要底栖动物划分为肉食者、浮游生物食者、碎屑食者和杂食者4个功能群.各功能群物种数占总物种数的百分比由高到低依次是肉食者、浮游生物食者、碎屑食者和杂食者.各功能群中肉食者的多样性指数最高,杂食者最低.各功能群的丰度、均匀度指数、多样性指数一般都是中潮区较高,高潮区和低潮区较低.大型底栖动物功能群的分布随潮区环境的改变而变化,是对生境状况的综合反映.     

Long-term studies of macrozoobenthos in intertidal and shallow subtidal habitats near the island of Norderney (East Frisian coast,Germany)

Near the East Frisian island of Norderney two sites are investigated permanently in order to study long-term fluctuations of macrozoobenthos: one transect (since 1977) at the northern side in shallow subtidal waters and another one (since 1976) at the sheltered southern side in the intertidal area of the Wadden Sea. Since 1980 the investigations have been continued in the frame of COST-47, sedimentary intertidal programme (including the shallow subtidal habitats colonized by the Macoma balthica community).The results up to 1984, respectively to 1985, are presented and the changes of abundance of the dominant species are discussed. Discussed are also the influences of water temperatures and sediment disturbances caused by wave action. There is evidence that the intertidal variety of the Macoma balthica community shows a greater stability than the subtidal variety.     

Long-term changes (1979–89) in the intertidal macrozoobenthos of the Oosterschelde estuary: are patterns in total density,biomass and diversity induced by the construction of the storm-surge barrier?

To evaluate the effects of the construction of a storm surge barrier in the Oosterschelde, long-term patterns (1979–89) in abundance and biomass of the intertidal macrozoobenthos were studied at 14 permanent stations. Additionally, data of a large-scale survey in late summer 1985 and 1989 were analysed. In this paper, patterns in general parameters are discussed.Late summer values of total biomass, total density, species richness, diversity and abundance- and biomass ratio show no overall significant trend during the study period. The changes in the hydrodynamics and the morphology of the Oosterschelde after the completion of the storm surge barrier do not seem to have influenced the normal patterns in benthic populations. The observed patterns are determined by the occurrence of severe versus mild winters, rather than by hydrodynamic changes caused by the construction of the barrier. Low biomasses, high densities (particularly of opportunistic species) and higher stress-values (abundance- and biomass ratio) in 1985(–87) indicate a temporal disturbance by severe winter weather. At the elevated COST-station 27, total biomass decreased sharply in 1985, due to a short-term increase in exposure time, caused by the manipulation of the storm surge barrier.     

Impact of Macrozoobenthos on Two-Dimensional Small-Scale Heterogeneity of Pore Water Phosphorus Concentrations: <Emphasis Type="Italic">in-situ</Emphasis> Study in Lake Arendsee (Germany)

An in-situ study was conducted in Lake Arendsee to study the influence of macrozoobenthos on pore water phosphate concentrations, and to investigate the importance of macrozoobenthos in causing small-scale heterogeneity. Two-dimensional pore water samplers with a high spatial resolution were exposed for 14 days at two sampling points with different water depths. Macrozoobenthos densities and the corresponding pore water phosphate concentrations were determined. In profundal sediments with chironomids (mean density: 480 m⁻²) the pore water phosphate concentration showed more patchiness (heterogeneity index 0.69) than in sediments without chironomids (heterogeneity index 0.38). Macrozoobenthos might affect the sediment environment mainly through bioirrigation, bioturbation, secretion, and digestion. It is most likely that the hot spots are caused by secretions from chironomids which intensify the microbially mediated P-release. The small-scale horizontal heterogeneity of pore water concentrations due to macrozoobenthos activities is insufficiently considered in many limnological studies focusing on vertical changes of pore water concentrations to investigate biogeochemical processes in sediment and to estimate internal nutrient loading. In sediments inhabited by macrozoobenthos the number of replicates should be high due to the extreme variability of single profiles of the two-dimensional sampler, as well as of averaged profiles simulating classical one-dimensional pore water analysis techniques. In cases where the profundal sediment is macrozoobenthos-free, single deployments of one-dimensional pore water samplers are well suited to describing pore water chemistry. Thus, determination of macrozoobenthos density is essential for study design.     

胶州湾潮间带大型底栖动物次级生产力的时空变化

根据2009年4个季度月在胶州湾潮间带进行的大型底栖动物调查,利用Brey经验公式、Tumbiolo 和 Downing模型以及Brey估算模型对潮间带大型底栖动物次级生产力进行了估算。结果表明,胶州湾潮间带大型底栖动物年均次级生产力在5.3-29.9 g AFDW · m^-2 · a^-1之间;不同季节次级生产力存在较大差异,以夏季最大,春、秋季次之,冬季最小。年均次级生产力在潮区间的分布从高至低依次为低潮区E,中潮区B、C、D和高潮区A,不同季节和不同估算方法的结果稍有差别。春季大型底栖动物次级生产力最高的潮区为潮区D,夏、秋季均为潮区E,冬季为潮区B。贝类养殖活动是影响本海域次级生产力时空变化的主要因素。应用不同经验模型的次级生产力估算结果未取得一致:春季3个估算值间存在明显差异;夏季Brey经验公式与Brey模型估算值基本一致,Tumbiolo 和 Downing模型估算值偏低;秋、冬季Tumbiolo 和 Downing模型与Brey模型估算结果相近,Brey经验公式估算值偏高。Wilcoxon检验表明3种方法对次级生产力的估算值差异显著。大型底栖动物群落种类组成和海域水温特征可能是造成不同模型次级生产力估算差异的主要原因。     

三门湾大型底栖动物群落结构及其与环境因子的关系

为了解三门湾大型底栖动物群落的现状和动态变化,分别于2015年11月、2016年2月、5月和8月在三门湾海域用阿氏拖网对大型底栖动物进行调查。结果表明: 经鉴定,大型底栖动物有119种,主要类群为鱼类、甲壳类和软体动物,占种类总数的79%。大型底栖动物全年优势种为细螯虾、长额超刺糠虾和六丝钝尾虾虎鱼,不同季节优势种的变化明显,种类差异性较大。大型底栖动物的年平均生物量和平均栖息密度分别为0.025 g·m^-2和0.07 ind·m^-2。三门湾大型底栖动物各季节的Shannon多样性指数为2.21～3.18,Margalef物种丰富度指数为3.25～3.78,Pielou均匀度指数为0.53～0.79。ABC曲线分析显示,在春季和冬季,群落受到中等程度干扰;而在夏季和秋季,群落受到轻微扰动。典范对应分析结果显示,水深、温度、盐度和pH值是影响大型底栖动物群落的最主要环境因子。     

江苏滆湖大型底栖动物群落结构及其与环境因子的关系

为了解滆湖大型底栖动物群落结构特征及其与环境因子的关系,于2013—2014年对滆湖20个采样点的大型底栖动物按季节进行了8次调查,同时对14项水环境指标进行了逐月监测.结果表明: 共采集到大型底栖动物25种,其中软体动物3种,占12%,摇蚊幼虫12种,占48%,寡毛类4种,占16%,甲壳类4种,占16%.优势种为霍甫水丝蚓、苏氏尾鳃蚓、中国长足摇蚊和太湖裸须摇蚊.摇蚊幼虫和寡毛类存在显著的空间和季节变化.氮、磷营养元素和水温对滆湖水域环境状况有较大影响,且总氮(TN)、硝态氮(NO₃^--N)和溶解氧(DO)均表现出显著的空间和季节变化.相关性分析表明,TN和NO₃^--N是影响滆湖大型底栖动物群落结构的主要水环境因子,环境变量可以较好地解释主要类群的变化.     

Influence of the Thin Drift Algal Mats on the Distribution of Macrozoobenthos in Kõiguste Bay, NE Baltic Sea

Macrozoobenthic communities within and outside of the drift algal mats were compared in Kõiguste Bay, NE Baltic Sea. The patches of the drift algae were on average 0.5–1 km wide in diameter covering about 25% of the total bottom area of the bay. Thickness of the mat did not exceed 6 cm. The biomass of the mat varied between 35 and 1391 g dw m^?2. The drift algal mats had no clear negative effect on macrozoobenthos except for a few infaunal species. The drift algae favoured several detrivorous, herbivorous and carnivorous species. Among the studied variables, the thickness of algal mat and oxygen concentration at near-bottom layer explained the best the structure of macrozoobenthos. Total number of invertebrate species increased curvilinearly with the thickness of algal mat having the peak value at 3–5 cm thick algal mat. To conclude, moderate drift algal mats increased habitat complexity and, thus, the diversity of benthic faunal assemblages in otherwise poorly vegetated coastal areas.     

Response by macrozoobenthos biomass to water level regulation in some Finnish lake littoral zones

The relationship of the macrozoobenthos biomass in the littoral area to the yearly fluctuation in water level and the characteristics of the area or lake are studied using data collected from sheltered bays in regulated and natural waters. Most of the lakes were clear and oligotrophic. The benthos biomass at all depths in the littoral decreased with increased water level fluctuation, provided that the transparency of the water was uniform.The macrozoobenthos biomass in the 0–3 m depth zone could be predicted fromlog macrozoobenthos biomass (mg ODW) m^-2=4.25-1.33 (log Biomass Index) in which the Biomass Index is calculated as% MathType!MTEF!2!1!+-% feaafiart1ev1aaatCvAUfeBSjuyZL2yd9gzLbvyNv2CaerbuLwBLn% hiov2DGi1BTfMBaeXatLxBI9gBaerbd9wDYLwzYbItLDharqqtubsr% 4rNCHbGeaGqiVu0Je9sqqrpepC0xbbL8F4rqqrFfpeea0xe9Lq-Jc9% vqaqpepm0xbba9pwe9Q8fs0-yqaqpepae9pg0FirpepeKkFr0xfr-x% fr-xb9adbaqaaeGaciGaaiaabeqaamaabaabaaGcbaGaaeOqaiaabM% gacaqGVbGaaeyBaiaabggacaqGZbGaae4CaiaabccacaqGjbGaaeOB% aiaabsgacaqGLbGaaeiEaiaab2dacaqGGaGaaeiiaiaabccacaqGGa% GaaeiiaiaabccacaqGGaGaaeiiaiaabccacaqGGaGaaeiiaiaabcca% caqGGaGaaeiiaiaabccacaqGGaGaaeiiaiaabccacaqGGaGaaeiiai% aabccadaWcaaabaeqabaGaae4DaiaabggacaqG0bGaaeyzaiaabkha% caqGGaGaaeiBaiaabwgacaqG2bGaaeyzaiaabYgacaqGGaGaaeOzai% aabYgacaqG1bGaae4yaiaabshacaqG1bGaaeyyaiaabshacaqGPbGa% ae4Baiaab6gacaqGGaGaaeyAaiaab6gacaqGGaGaaeiDaiaabIgaca% qGLbGaaeiiaiaabchacaqGYbGaaeyzaiaabAhacaqGPbGaae4Baiaa% bwhacaqGZbGaaeiiaiaabMhacaqGLbGaaeyyaiaabkhaaeaacaqGOa% GaaeyBaiaabUdacaqGGaGaae4yaiaabggacaqGSbGaae4yaiaabwha% caqGSbGaaeyyaiaabshacaqGLbGaaeizaiaabccacaqGMbGaaeOCai% aab+gacaqGTbGaaeiiaiaab2gacaqGVbGaaeOBaiaabshacaqGObGa% aeiBaiaabMhacaqGGaGaaeyBaiaabwgacaqGHbGaaeOBaiaabccaca% qG2bGaaeyyaiaabYgacaqG1bGaaeyzaiaabohacaqGPaaaaeaacaqG% tbGaaeyzaiaabogacaqGJbGaaeiAaiaabMgacaqGGaGaaeizaiaabM% gacaqGZbGaae4AaiaabccacaqG2bGaaeyyaiaabYgacaqG1bGaaeyz% aiaabccacaqGPbGaaeOBaiaabccacaqG0bGaaeiAaiaabwgacaqGGa% Gaae4CaiaabggacaqGTbGaaeyzaiaabccacaqGVbGaaeiCaiaabwga% caqGUbGaaeiiaiaabEhacaqGHbGaaeiDaiaabwgacaqGYbGaaeiiai% aabohacaqGLbGaaeyyaiaabohacaqGVbGaaeOBaiaabccacaqGOaGa% aeyBaiaabMcaaaaccaGae8hiaaIaaKiEaiab-bcaGiaaigdacaaIWa% GaaGimaiaac6caaaa!CBD8!\[{\text{Biomass Index = }}\frac{\begin{gathered} {\text{water level fluctuation in the previous year}} \hfill \\ {\text{(m; calculated from monthly mean values)}} \hfill \\ \end{gathered} }{{{\text{Secchi disk value in the same open water season (m)}}}} \user1{x} 100.\]The whole illuminated littoral shifts due to water level fluctuation, which disturbs the zonation of the benthos. Such an increase or decrease in benthic biomass has been observed after one year of disturbance due to water level fluctuation. It need, however, a study based on the carefully planned and collected data, in which it can be taken account by a multivariate statistical analysis also the interactions between the important factors affected the littoral benthos.     

Macrozoobenthos of Lake Peipsi-Pihkva: taxonomical composition, abundance, biomass, and their relations to some ecological parameters

The large but shallow (3,558 km², up to 15.3 m deep) lake is eutrophic, with Chironomus plumosus and Potamothrix hammoniensis as dominating macroinvertebrates in the profundal. The extensive well-aerated sublittoral with sandy bottom sediments has a mesotrophic appearance and supports a diverse fauna with several oxyphilous species, including a very abundant population of Dreissena polymorpha. The phytophilous fauna is limited to small sheltered areas only. The average abundance of the small animals of macrozoobenthos (without big molluscs) was 2,617 ind. m^–2, their biomass 12.34 g m^–2 (corresponding to 52.2 kJ m^–2) in 1964–1994. The same figures for big molluscs (mostly Dreissena) were 304 ind. m^–2 and 238 g m^–2 in 1964–1994, and even 864 ind. m^–2 and 687 g m^–2 in 1985–1988, at the time of their special mapping. The sublittoral zone revealed the lowest biomass of small animals but the highest biomass of big molluscs. The southern, shallower lake regions, more enriched with nutrients and better protected from wind, revealed a significantly higher biomass of small macrozoobenthos in the near-shore zone than the cleaner and open northern part, while no positive effect of enrichment was observed neither in the biomass of profundal zoobenthos nor in that of big molluscs. The production of the small macrozoobenthos was calculated as 111 and 53 kJ m^–2 during two annual cycles in Lake Peipsi s. s., the most productive period being the autumn overturn. Lake Peipsi-Pihkva has the highest abundance and biomass of macrozoobenthos among the large lakes of North Europe.     

Environmental monitoring in Baden-Württemberg with special reference to biocoenotic trend-monitoring of macrozoobenthos in rivers and methodical requirements for evaluation of long-term biocoenotic changes

Biomonitoring methods from a comprehensive study of man-made impacts on urban and on the near-natural environment are presented. Part of the environmental monitoring in Baden-Württemberg is a biocoenotic trend-monitoring project on macrozoobenthos in running waters which has resulted in a database enabling long-term trend assessment of biocoenosis in diverse rivers and streams in the future. About 561 species of macrozoobenthos have been recorded (21 species for the first time in Baden-Württemberg). Data are analysed for different purposes: methodological requirements for aquatic trendbiomonitoring, status of endangerment according to the Red Data Book, and first assessment of faunistic long-term changes in the River Rhine.Calculation of cumulative species numbers over number of samples offers sampling success and therefore represents a good way to show how sure or complete results of a given faunistic approach are at a given time. One sample provides less than 25% of the fauna recorded within a three years period of quarterly inspections. To collect the main fraction (90%) of species, it takes 3 years of quarterly collections if all species recorded only once during the whole period are neglected. Several rare species were recorded within the project. 34% of mayflies, stoneflies and caddisflies are endangered.The River Rhine and its changes in faunal composition within the last century is the example to illustrate the principle of biocoenotic trend-monitoring. The more recent samples of the macrobenthic fauna of the River Rhine indicate an improved quality and diversity because of improved water quality. Several species, indicative of good water quality have returned, and invasion of neozoans is still high, too. However, with respect to extinct species of macrozoobenthos, especially stoneflies, mayflies and caddisflies, mentioned by former authors, there is still a marked absence of indigenous species in the River Rhine.     

Integrated lake monitoring in Europe the macrozoobenthos in the four target lakes in Finland

In four small ( 1 km²) Finnish lakes belonging to the Integrated Monitoring Programme (UN ECE), macrozoobenthos has been studied at different depths since 1989. The lakes are situated between 61°N–70°N latitudes from the southern boreal coniferous region up to the forest tundra ecotone. The macrozoobenthos of the lakes was very different compared to each other, but chironomids were important in all lakes. Acid-sensitive taxa (molluscs, some mayflies) were lacking in one of the lakes because of its low pH. In all lakes the zoobenthos could indicatee.g. the wideness of the littoral region and stagnation conditions or groundwater input through the bottom. In future, both litoral and profundal sampling is needed because of the multi-purpose character of the monitoring (acidification, trophic level).     

水稻突变体des2和des5的研究和定位

小穗发育是决定水稻产量的主要农艺性状,鉴定控制小穗发育的关键基因对研究和分析调控农艺性状的分子机理是至关重要的.本文中,我们鉴定了一组小穗数目明显减少的突变体,命名为decteased spikelets(des),这里详细研究des2和des5两个突变体.结果显示des2是由单基因隐性位点控制,图位克隆将此位点定位到6号染色体的长臂上,并最终克隆了此基因,发现des2是moc1的一个新的等位突变体.定位克隆和序列分析显示在des5中,LAX基因的编码HLH(螺旋一环一螺旋)结构域的区域发生了一个点突变,暗示des5是lax的一个新的等位突变体.我们的结果暗示小穗和水稻叶腋分枝的发育受相同的遗传途径调控.     

基于生物量的大型底栖动物功能摄食群结构 及生态质量评价

基于2011年5月和9月2个航次获取的生物及环境数据, 分析了渤海湾大型底栖动物的功能摄食群组成, 并首次利用以生物量构建的摄食均匀度指数(the feeding evenness index, bj_FD)和多元AZTI海洋生物指数(multivariate-biomass AZTI marine biotic index, M-bAMBI)对渤海湾生态质量进行评价。结果表明, 渤海湾大型底栖动物功能群由4类组成, 分别是肉食者、碎屑食者、浮游生物食者和杂食者, 未发现植食者。2个航次均以浮游生物食者和杂食者的生物量最高, 碎屑食者最低。聚类分析结果表明海河口内大型底栖动物群落功能摄食群组成与其他区域明显不同。两个航次均以海河口的重金属潜在生态风险指数值(risk index, RI)较低, 且5月航次该指数沿河口向外有明显的空间分布梯度。bj_FD平均值为0.28, 指示研究区大部分区域生态质量较差, 其中低值区集中在海河口、北塘口及其附近海域, 与风险指数值的低值区基本吻合。BEST分析表明温度、盐度、重金属及营养盐等是影响bj_FD变化的主要环境因子。与M-bAMBI相比, bj_FD对海河口及北塘口较差的环境质量状况更为敏感。总体上, bj_FD适用于评价渤海湾的生态质量。     

Hydrophyte-macroinvertebrate interactions in Zwemlust,a lake undergoing biomanipulation

In two years after biomanipulation of Lake Zwemlust (The Netherlands), macrophytes (helophytes, elodeids) and filamentous algae developed luxuriantly in the lake. They influenced the structure of macroinvertebrate communities inhabiting them. Macrophytes and algae, by changing environmental and trophic conditions, also affected the composition of macrozoobenthos. Vascular plants served as an important source of food for zoobenthos and phytofauna, mainly after they were decomposed. Filamentous algae were consumed readily alive by many animals. Invertebrates appeared to be important as a potential nutrient source for hydrophytes.     

浙江分水江水库大型底栖动物群落结构及水质评价

2008年11月-2009年10月,在浙江桐庐分水江水库设置7个站点对大型底栖动物进行逐月调查.结果表明:调查共采集到37种底栖动物,主要由寡毛纲和摇蚊科物种组成.春、夏、秋季优势种均为霍甫水丝蚓,冬季优势种为羽摇蚊.直接收集者在物种数量、密度和生物量上均占绝对优势.群落年均密度和年均生物量分别为(488.0±48.8) ind·m-2和(1.86±0.49) g·m-2.底栖动物密度在站点间无明显差异但存在显著的季节变化,呈现春季＞夏季＞冬季＞秋季的趋势,生物量在站点、季节间均无显著差异.水温和水深是影响底栖动物时空分布的主要因子.Shannon多样性指数和Goodnight-Whitley指数不适合用于该水库的水质评价,其他指数综合显示分水江水库属于轻度污染.