虾蟹混养池塘浮游植物群落结构的变化特征

为摸清锯缘青蟹(Scylla serrata)与斑节对虾(Penaeus monodon)混养池塘浮游植物种群结构的变化特征,于2018年3-11月对广州市番禺区十六涌3个养殖池塘中的浮游植物开展了逐月调查,并通过冗余分析(RDA)探讨了浮游植物与环境因子的相关性。结果表明,养殖池塘中共鉴定出浮游植物29种,主要由硅藻、蓝藻、甲藻、绿藻和裸藻5大门类组成,其中硅藻种类最多(19种),占浮游植物种类数的65.5%;其次是蓝藻,共5种,占浮游植物种类数17.2%;甲藻3种,绿藻和裸藻各1种。共出现优势种16种,主要为直舟形藻(Navicula directa)、奇异菱形藻(Nitzschia paradoxa)、柔弱菱形藻(Nitzschia delicatissima)、尖布纹藻(Gyrosigma acuminatum)、大角角藻(Ceratium macroceros)和小颤藻(Oscillatoria tenuis)等。浮游植物细胞密度介于2.56×103~189.2×103个·m-3,Shannon-Weaver多样性指数介于0.468~2.597。浮游植物与环境因子相关性RDA结果表明,营养盐、盐度和pH是影响养殖塘浮游植物种群结构的主要环境因子。     

Taxonomic and functional macroinvertebrate diversity of high-altitude ponds in the Macun Cirque,Switzerland

1. Global environmental change is threatening freshwater biodiversity with ecological impacts predicted to be particularly severe in high-altitude regions. Despite this, an ecological understanding of high-altitude pond networks remains patchy, with only limited knowledge of the environmental and spatial predictors of taxonomic and functional diversity. Moreover, previous studies of pond ecosystems have focused primarily on taxonomic richness and largely overlooked functional diversity.
2. This study examined the influence of local environmental and spatial factors on taxonomic and functional α and β diversity (including the turnover and nestedness-resultant components) of 17 high-altitude (~2,500 m above sea level) pond macroinvertebrate communities, in the Macun Cirque, Switzerland.
3. Spatial processes (pond connectivity) were important drivers for taxonomic α diversity, while local environmental variables (pond permanence and surface area) were important determinants of functional α diversity. Species turnover was the most important component of β diversity for taxonomic composition, and functional composition demonstrated a nested spatial pattern.
4. Variation in taxonomic and functional composition (and the turnover and nestedness components of β diversity) were determined by local environmental variables despite the limited environmental gradients within the pond network. No significant effects of spatial variables on community composition were recorded for either facet of diversity, indicating that compositional variation was determined at a local scale. Water temperature, depth and pond permanence were consistently the most important measured drivers of diversity.
5. Given the importance of both spatial and environmental variables in structuring taxonomic and functional diversity, landscape-scale conservation and management activities that aim to improve or protect high-altitude freshwater biodiversity should focus on maintaining connectivity among ponds and environmental heterogeneity, particularly pond surface area, water depth, and hydroperiod. Understanding the mechanisms driving taxonomic and functional diversity will be critically important for the management and conservation of macroinvertebrate communities in high-altitude pond networks in the face of climatic warming.

     

黄海南部近岸海域鱼类群落结构与区系划分

黄海南部海域具有复杂的水团结构和海流环境,使该海域鱼类群落产生较为复杂的空间结构。为研究黄海南部近岸海域鱼类群落结构特征,实验根据2014—2015年对该海域进行4个季度的底拖网调查数据,利用多元统计方法分析了该海域鱼类群落的分布格局并比较了各群落的相对生物量、生物多样性、优势种等结构特征。应用聚类分析(cluster)和多维标度排序(MDS)分析将黄海南部近岸海域划分为海州湾群落与江苏近岸群落;海州湾群落的平均相对资源量和生物多样性均高于江苏近岸群落,而暖温性与暖水性鱼类所占比重相对较低;海州湾群落的优势种主要为方氏云鳚、大泷六线鱼和日本鳀等,季节变化显著;江苏近岸群落的优势种为短吻红舌鳎、途、棘头梅童鱼和黑鳃梅童鱼等,季节变化不明显。研究表明,黄海南部近岸海域可划分为海州湾区系与江苏近岸区系,其鱼类群落结构特征具有显著差异。海流、水团、底质类型及水深等环境因子是形成鱼类群落结构差异的主要因素。     

Effects of Chaetomorpha valida bloom development on the structure and succession of the phytoplankton community in Apostichopus japonicus culture ponds

Phytoplankton is very important to aquaculture ecosystem and is vulnerable to ambient conditions. In recent years, Chaetomorpha valida, an invasive filamentous green alga, has been blooming in Apostichopus japonicus culture ponds. Here, we conducted a 5‐month investigation, examining whether that bloom affects the structure and succession of the pond phytoplankton community. Differences in dissolved oxygen, light and nutrient concentrations in both bloom and normal (non‐bloom) areas varied monthly. The species and populations of phytoplankton communities in both the bloom and normal areas showed no significant differences when C. valida biomass was low, but through time, differences became increasingly significant. Species in normal areas remained relatively stable as the numbers and species of the dominant species changed little and the diversity and evenness indexes increased monthly. In bloom areas, species abundance decreased gradually with most of the decrease affecting Bacillariophyta. Here, the number of dominant species remained stable from May to July but decreased significantly in August and September. Diversity and evenness indexes also decreased significantly, and the differences between the 2 areas increased rapidly. Results showed that C. valida bloom in A. japonicus culture ponds influenced both the structure and succession of the phytoplankton community, contributing to comprehensive assessment of the effects of C. valida bloom on aquaculture ecology.     

青海湖裸鲤放养密度对养殖池塘浮游动物群落结构的影响

为进一步了解青海湖裸鲤(Gymnocypris przewalskii)养殖池塘中养殖密度与浮游动物群落结构间的关系,通过对不同养殖密度的青海湖裸鲤池塘进行连续的采样调查,测定浮游动物的群落结构、水质指标以及青海湖裸鲤的生长情况。讨论并分析青海湖裸鲤养殖密度对池塘浮游动物群落结构的影响。结果显示:试验期间共测定出浮游动物38种,以轮虫为主,其数量占整个浮游动物种类的61. 5%;浮游动物密度、生物量、多样性指数在中、高养殖密度条件下均随着养殖时间的增加呈现下降趋势。研究表明:高密度养殖对浮游动物群落结构影响较大,中、高密度养殖鱼苗对浮游动物的高摄食压力使浮游动物生长受到限制,浮游动物种类减少并趋于小型化,不利于养殖水环境的稳定。     

Pond macrophyte assemblages,biodisparity and spatial distribution of ponds in the Northumberland coastal plain,UK

1. Macrophyte assemblages from 50 ponds throughout the Northumberland coastal plain were surveyed together with adjacent landscape, pond morphology and physical and chemical variables. 2. TWINSPAN classification and CANOCO ordinations suggested that, whilst distinct macrophyte assemblages recurred, relationships of assemblages to environmental variables were weak. Geographical variables (northing, easting and altitude) plus extent of drying out were the most important variables in the CANOCO ordination linking pond types and environmental factors. Most assemblages could be found across a wide range of conditions. Classifications using only aquatic or emergent taxa gave different results. 3. Regression analyses suggested that total species richness of aquatic taxa increased with greater area of deeper water and pH. Emergent taxa richness increased with pond area, areas of deeper water and drying down, and decreased with altitude. The level of prediction was weak. 4. Pond types, defined by their macrophytes, were dispersed throughout the region and interspersed so that adjacent ponds often supported different assemblages. No habitat or locale supported unique types or unusual variety. 5. Local, anecdotal classifications of pond types in Northumberland, e.g. ‘subsidence ponds’, proved unreliable. Classification of ponds using macrophytes suggested greater biodisparity than such simplistic categories. The two main approaches to pond assessment (spatial surveys and ecological classification) need to be combined for sound assessment of the local status of ponds. This would benefit regional selection of pond types for conservation. © 1998 John Wiley & Sons, Ltd.     

光合细菌强化对精养鱼塘藻类群落结构的影响

通过定期向池塘投加光合细菌,研究了有益微生物强化对精养鱼塘浮游藻类群落结构的影响。结果显示:光合细菌强化塘(试验塘)藻类组成以绿藻、硅藻为主,养殖前期(5—6月初),以针杆藻、直链藻等占优势,中后期(7—9月)则以绿球藻、栅藻、盘星藻、小环藻、菱形藻等为优势种,水色呈淡绿、黄褐色等良好状态;而对照塘藻类组成在前期与试验塘没有明显差异,但在中后期出现明显变化,以微囊藻、颤藻、鱼腥藻、席藻等蓝藻占优势。试验塘藻类生物量显著低于对照塘(P<0.05),且对照塘生物量波动变化大,蓝藻数量所占比例可高达77.6%,远高于试验塘蓝藻比例(均值低于25.0%);此外,藻类Shannon-Wiener指数、Pielou指数试验塘均大于对照塘。结果表明:光合细菌的定期添加有效控制了蓝藻增值,保持了藻类多样性,使精养鱼塘藻相趋于稳定,有利池塘养殖。     

2009年春、夏季浙江中北部沿岸海域浮游动物群落特征

2009年春季(4月)和夏季(8月)对浙江中北部沿岸海域(28°30'～30°45'N、121°30'～123°15'E)浮游动物的种类组成、优势种类、数量分布及群落特征进行了调查及分析。结果表明,春、夏季调查海域共鉴定出浮游动物177种,属18个大类,其中桡足类为主要优势类群。春、夏季间无共同优势种,春季主要优势种为中华哲水蚤(Calanus sinicus)、拟细浅室水母(Lensia subtiloides)、五角水母(Muggiaea atlantica)和假磷虾(Pseudeuphausia)幼体;夏季主要优势种为双生水母(Diphyes chamissonis)、肥胖箭虫(Sagitta enflata)、软拟海樽(Dolioletta gegenbauri)和亚强真哲水蚤(Eucalanus subcrassus)。浮游动物平均丰度和平均生物量季节变化均极显著(P<0.001),春季丰度介于8.80～581.19 cfu/m3之间,平均丰度为164.48 cfu/m3;夏季平均丰度介于15.09～1102.07 cfu/m3之间,平均丰度为352.47 cfu/m3;春季生物量介于3.76～569.50 mg/m3之间,生物量为140.16 mg/m3;夏季平均生物量介于16.35～1603.09 mg/m3之间,平均生物量为442.73 mg/m3。春、夏季节间群落结构指数存在着较大的差异,个体数、种类数、多样度、丰富度和均匀度差异均极显著(P<0.001)。     

2009年春夏季浙江中北部近岸海域浮游植物群落特征

分析了2009年春季(4月)和夏季(8月)在浙江中北部海域(121°30′~123°30′E、28°30′~30°45′N)进行调查所采集的浮游植物样品,对调查海域浮游植物群落的物种组成、细胞丰度的平面分布、优势种分布和群落的多样性指数等群落特征进行分析研究。初步鉴定浮游植物6门62属169种,硅藻占绝对优势。春季主要优势种为中肋骨条藻、蛇目圆筛藻、星脐圆筛藻和辐射圆筛藻。夏季主要优势种为尖刺拟菱形藻、窄隙角毛藻、中肋骨条藻和远距角毛藻。不同季节优势种既有交叉又有演替;春季浮游植物细胞丰度介于0.01×104~40.67×104cells/m3之间,平均为3.80×104cells/m3;夏季介于0.28×104~6 546.22×104cells/m3之间,平均为467.59×104cells/m3。细胞数量季节变化显著,浮游植物平面分布特征呈明显的斑块状分布,优势种明显。春季的香农-维纳指数和Pielou均匀度指数都好于夏季,而细胞丰度却低于夏季。     

诏安湾浮游植物的生态特征研究

根据2001年5月、8月和11月对诏安湾网采浮游植物样品的分析鉴定结果,对浮游植物的种类组成和细胞数量等的平面分布和季节变化进行了分析研究,结果表明:诏安湾浮游植物种类丰富,共鉴定浮游植物5门58属172种,浮游植物的生态类群以广布种为主;浮游植物细胞数量的季节变动范围在2.03×106cell/m3～4.01×107cell/m3,数量高峰出现在11月,这与海水中无机氮和活性磷酸盐含量的明显上升有关.海水中活性磷酸盐为影响诏安湾浮游植物生长繁殖的限制因子之一.     

旧镇湾浮游植物的生态特征研究

根据2001年5月、8月和11月对旧镇湾网采浮游植物样品的分析鉴定结果,对浮游植物的种类组成和细胞数量等的平面分布和季节变化进行了分析研究,并探讨了浮游植物分布与环境的关系,结果表明:3次调查共鉴定浮游植物3门46属131种,细胞数量的季节变动范围在2.18×105cell/m3～5.75×107cell/m3,均值为2.02×107cell/m3,种类数和细胞数量的季节变化规律相同,即春季＞夏季＞秋季.浮游植物的分布与水温、盐度、营养盐、养殖贝类等环境因素有关.     

长江芜湖江段鱼类多样性及其群落结构的时空格局

为制定合理的渔业资源保护措施与管理对策,2009年按季度共4次调查了长江芜湖江段鱼类多样性及其群落结构。结果显示:该江段现有鱼类54种,其中以似鳊(Parabramis pekinensis)、油(Hemiculter bleekeri bleek-eri warpacho)、短颌鲚(Coilia brachygnathus Kreyenberg et Pappenheim)、鲫(Carassius auratus)等中小型鱼类为常见种和优势种,表明了该江段的鱼类组成存在明显的小型化特点。长江干流沿岸浅水区的鱼类多样性最高,江心深水区最低,而青弋江支流、漳河支流和漳河河口的居中,青弋江的鱼类种数和个体数都显著低于沿岸浅水区,但漳河的鱼类数量与沿岸浅水区无明显差异。江心深水区的鱼类群落与其它样点明显不同,而青弋江的鱼类群落与沿岸浅水区、漳河及其河口的鱼类群落也存在部分差异。鱼类群落结构的季节动态无显著性。     

Threadfin shad impacts phytoplankton and zooplankton community structures in channel catfish ponds

Plankton community structure and chlorophyll a concentration were compared in twelve 0.1 ha earthen ponds co‐stocked with channel catfish (Ictalurus punctatus Rafinesque, 1818) in a multiple‐batch culture (initial biomass=5458 kg ha^?1) and a planktivore, threadfin shad (Dorosoma petenense Güther, 1867; initial biomass=449 kg ha^?1), during the April–November growing season. We used a completely randomized design in a 2 × 2 factorial arrangement to test the planktivore level (presence or absence of threadfin shad) and channel catfish feeding frequency (daily or every third day). Channel catfish were fed a 32% protein feed to apparent satiation on days fed. The presence of threadfin shad affected phytoplankton and zooplankton community structure more than did feeding frequency, and the impact in ponds was more pronounced after 1 July. The numbers of all major groups of zooplankton were lower in ponds with threadfin shad, but were unaffected by the feeding frequency. Chlorophyll a concentration before 1 July was higher in ponds with threadfin shad and unaffected by the feeding frequency, whereas after 1 July it was higher in ponds without threadfin shad and that were fed daily. Phytoplankton community structure after 1 July was dominated by nuisance algal bloom genera of cyanobacteria in ponds without threadfin shad and by Bacillariophyceae in ponds with threadfin shad.     

2004年秋季长江口海域浮游植物的群落结构和多样性

2004年9月20日~10月9日对长江口海域浮游植物的种类组成、多样性、丰度及其分布进行了调查研究。本次调查,长江口海域共鉴定浮游植物2门26属68种(含4个变种、6个不确定种),主要为温带近岸性种,其中硅藻门有21属51种,占总种数75%,甲藻门有5属17种,占总种数的25%。硅藻门中角毛藻属(Chaetoceros)和圆筛藻属(Coscinodiscus)的种类最多,分别为17种(占硅藻总种数的33.33%)和7种(占硅藻总种数的13.73%),甲藻门中以角藻属(Ceratium)为主,有10种,占甲藻总种数的58.8%。浮游植物数量平均为1400.00×104cells/m3。硅藻的平均数量为1392.69×104cells/m3,占浮游植物总量的99.3%;甲藻的平均细胞数量为7.31×104cells/m3,占浮游植物总量的0.7%。多样性指数平均值为1.90,而均匀度指数平均值为0.68。浮游植物密集区出现在调查区域的中部,靠近长江入海口水域。浮游植物的优势种主要为:中肋骨条藻(Skeletonema costatum(Greville)Cleve)、尖刺菱形藻(Nitzschia pungens Grunow)、菱形海线藻(Thalassionema nitzschioides Grunow)、洛氏角毛藻(Chaetoceros lorenzianus Grunow)、柔弱角毛藻(Chaetoceros debilis Cleve)、窄隙角毛藻(Chaetoseros affinis Lauder)和旋链角毛藻(Chaetoecros curvisetus Cleve)。本次调查长江口海域的浮游植物可划分为:东北部组群、近河口组群和南部组群3个主要生态类型。     

胶州湾中部海域虾类群落结构及其多样性

根据2008年9月至2009年8月在胶州湾中部海域进行的逐月底拖网调查数据,应用相对重要性指数、生物多样性指数和多元统计分析等方法对虾类群落结构及多样性进行了研究。结果表明:该调查海域捕获虾类共17种,隶属于6科15属。虾类相对资源量具有明显的月间变化,9月、10月、6月资源量较高,平均网获质量的变化范围为223.9~3 422.9 g/h,平均网获尾数为41~1 608 ind/h;优势种组成具有较为明显的月间变化,全年的优势种为鹰爪虾(Trachysalambra curvirostris)、细巧仿对虾(Parapenaeopsis tenella)和日本鼓虾(Alpheus japonicus)。虾类种类丰富度指数(D)的变化范围为0.77～1.89,Shannon-wiener多样性指数(H′)变化范围为0.90～2.34,均匀度指数(J)变化范围为0.26～0.76,多样性指数月变化较大,且春夏季高于秋冬季。CLUSTER聚类分析与MDS分析可将胶州湾中部海域全年虾类群落划分为4个月份组群:Ⅰ组群(4月、5月),Ⅱ组群(12月—翌年3月),Ⅲ组群(6月、9月、10月)和Ⅳ组群(7月、8月、11月)。ANOSIM分析表明,Ⅱ组群与Ⅲ组群、Ⅱ组群与Ⅳ组群差异显著,其他组群间差异不显著。各组群典型种与组群间分歧种对群落结构的影响明显。BIOENV分析表明,底层水温是影响胶州湾中部海域虾类群落结构月变化的主要环境因子。本研究旨在为保护与合理利用胶州湾海域虾类资源对策的制定提供科学依据。     

珠江口南沙海域浮游植物群落结构特征

基于2015年4月(丰水期)和2015年11月(枯水期)珠江口南沙海域的调查资料,分析该海域浮游植物的种类组成、优势度、细胞丰度及多样性。共鉴定出浮游植物5门44属76种,硅藻为最主要优势种群。丰水期优势种有2种,分别为新月筒柱藻(Cylindrotheca closterium)和中肋骨条藻(Skeletonema costatum);枯水期优势种有3种,分别为萎软海链藻(Thalassiosira mala)、中肋骨条藻和有棘圆筛藻(Coscinodiscus spinosus)。丰水期和枯水期浮游植物细胞丰度分别为651.91×104个·L-1和129.21×104个·L-1,2个时期细胞丰度分布都表现为近岸向离岸递增的趋势。调查海区的浮游植物Shannon-Wiener多样性指数(H')和Pielou均匀度指数(J')的平均值在丰水期分别为1.64和0.40,而在枯水期分别为1.58和0.41,多样性总体处于较低水平。典范对应分析结果表明,丰水期影响浮游植物群落结构的主要环境因子为盐度、温度、总氮和p H,枯水期为温度、透明度、磷酸盐和盐度。     

Ecology and conservation status of temporary and fluctuating ponds in two areas of southern England

• 1. A high proportion of ponds are temporary in nature, although the biodiversity value of such sites is still poorly recognized. This work explores the plant and macroinvertebrate communities of 76 temporary and fluctuating water bodies in two regions of southern England (Lizard Peninsula, Cornwall and New Forest, Hampshire) that have retained high pond densities. The ecology and conservation status of sites is examined, and comparisons made with ponds elsewhere in England and Wales.
• 2. Lizard and New Forest ponds supported 119 plant and 165 macroinvertebrate species respectively. Patterns of community similarity for plants and macroinvertebrates were highly concordant, taxa being related in a similar manner to measured environmental variables including pond area, depth, pH and water chemistry.
• 3. Patterns of pond occupancy revealed that most species were locally rare, over half occurring in less than 10% of ponds, and less than 10% being recorded from more than 50% of sites. More than 50% of ponds supported at least one nationally rare plant and almost 75% at least one nationally rare macroinvertebrate. These taxa occupied a wide range of pond types in each region, and did not have predictably different ecologies from common species.
• 4. Comparisons with ponds elsewhere in England and Wales revealed that Lizard and New Forest communities are nationally distinct, being most similar to ponds in areas of low intensity agriculture elsewhere in western Britain. Individual ponds in both regions supported more nationally rare taxa, on average, than ponds sampled in the national survey.
• 5. Ponds in the two areas have high conservation value, both regionally and nationally, supporting almost 75% of the global species richness of temporary ponds sampled across England and Wales. Within each region, many taxa are found in relatively few sites, and effective conservation of pond biodiversity will require a regional management approach.

Copyright © 2008 John Wiley & Sons, Ltd.     

Bacterial diversity in various coastal mariculture ponds in Southeast China and in diseased eels as revealed by culture and culture‐independent molecular techniques

Mariculture ponds are widely distributed in Chinese coasts and have become a threat to the health of coastal ecosystems. In order to improve our understanding on the microbial composition in mariculture environments, we sampled a variety of ponds farming different animals or plants around the Dongshan Island and Xiamen Island in Southeast China and isolated cultures from the tissues of diseased eels. Analysis by polymerase chain reaction (PCR)‐denaturing gradient gel electrophoresis (DGGE), clone library and direct culturing methods revealed highly diverse bacterial communities in these samples. Bacterial communities in the Dongshan samples were dominated by Alphaproteobacteria, Gammaproteobacteria and Bacteroidetes. The Gracilaria verrucosa pond harbours the most abundant species (20 DGGE bands), followed by Epinephelus diacanthus pond (18 bands), Haliotis diversicolor supertexta pond I (18 bands) and Penaeus vannamei pond (11 bands). In comparison with surface waters, Penacus orientalis pond sediment showed a much more complex bacterial community, from which only sequences affiliated with Deltaproteobacteria, Firmicutes, Acidobacteria and candidate phylum TM6 were found. Bacterial cultures in diseased eels were closely related to two pathogenic genera, Aeromonas in Gammaproteobacteria and Bacillus, in Firmicutes. Clones affiliated with another two genera, Escherichia and Vibrio, that have pathogenic potentials were also identified. Phylogenetic analysis of a total of 131 sequences showed that 48.9% of the sequences were clustered into Gammaproteobacteria and formed the most abundant group, followed by Alphaproteobacteria (19.1%), Firmicutes (7.6%), Bacteroidetes (5.3%), Deltaproteobacteria (5.3%), Actinobacteria (4.6%), Chloroplast (3.8%), Acidobacteria (2.3%), Cyanobacteria (1.5%), Betaproteobacteria (0.7%) and TM6 (0.7%). 43.7% (28/64) of the phylogenetic clusters cannot be classified into any known genus and 44.3% (58/131) of the sequences show <95% similarity to public database records, suggesting that abundant novel species exist in mariculture ponds. Gathering bacterial diversity data in mariculture ponds and diseased fish is meaningful for the prevention and control of fish diseases and for the improvement of our understanding of microbial ecology in a pond environment.     

虾池浮游微藻与养殖水环境调控的研究概况

在对虾养殖过程中,虾池中的浮游微藻群落结构和对虾的健康养殖有着密切关系,一些有益微藻能调节水体溶氧量（DO）和酸碱度（pH）,吸收氨氮（NH4-N）和亚硝氮（NO2-N）等有害物质,有效地调控养殖环境。但一些能分泌毒素的微藻也会给对虾的健康生长带来危害。数量和生物量占微藻总量比例均较高的浮游微藻优势种对整个虾池微藻群落结构的稳定起着重要作用,主导着微藻群落的功能发挥。不同养殖模式、养殖季节、养殖地域以及养殖阶段虾池中浮游微藻的优势种类分布、多样性等群落特征有差异。浮游微藻群落中优势种的变动规律和虾池中各种环境因子的动态密切相关,环境因子的变动会影响浮游微藻群落结构的变动。文章综述了对虾养殖生产实践中浮游微藻群落结构和生态调控特征的研究概况,并对在养殖中构建优良微藻藻相的方法进行了探讨。     

Spatio‐temporal patterns of fish assemblage structure in a coastal plain stream: appropriate scales reveal historic tales

Quantifying assemblage structure across spatio‐temporal scales is ecologically important and further aids in the understanding of community organisation processes. Currently, few studies have assessed assemblage structure across generous magnitudes of scale, and influences of processes (biotic and abiotic) responsible for structuring assemblages are still questioned. Using community and hydrologic data collected over a 22‐year period from a stretch of river nearing 150 km, we examined spatio‐temporal fish assemblage structural patterns in a temperate coastal plain stream. Results indicated that significant changes in assemblage structure across time were influenced by environmental disturbances, including drought and hurricane events. Assemblages were restructured in a punctuated manner directly following these events, and complete recovery of initial assemblage structure did not occur across the study period. Additionally, we found spatial differentiations between upstream and downstream assemblages, which were driven by greater abundances of several species in downstream sites. Our results suggest that assemblage structure is influenced by environmental variation, specifically, extreme disturbance events and spatial habitat heterogeneity.