An ecological investigation of the Myall Lakes region

This ecological study of the Myall Lakes, a lagoon system on the New South Wales central coast, presents the physical setting and characteristics of the Lakes’catchments and relates these characteristics to the hydrochemical features of surface and subsurface waters. In turn these hydrochemical features have been related to the aquatic communities. It is suggested that the predominance of forest vegetation and stable soils in the Lakes’catchment has assisted in retaining these lakes in a generally undisturbed state. Fluctuations of salinity, turbidity and ionic concentrations in the lower part of the system are controlled by natural inputs of rainfall, run-off and tidal flushings. However, Boolambayte Lake and particularly Myall Lake, the upper part of the system, appear to be isolated from these influences. The aquatic communities reflect these hydrochemical differences. The lack of flushing of waters in this upper part of the system, in Dirty Creek and to a lesser extent in the Myall River immediately upstream of the Broadwater, makes these areas particularly susceptible to pollution and eutrophication associated with increased development.     

Fish fauna, biogeography and conservation of freshwater fish in Poyang Lake Basin, China

A checklist of the fish of Poyang Lake Basin based on an extensive survey and literature review is presented. A total of 220 species and subspecies belonging to12 orders, 27 families and 100 genera, have been recorded. Of these, 131 species are endemic to China. Based on cluster analysis with presence-absence data, freshwater ecosystems in Jiangxi Province are divided into two regions, the Xunwushui River region and the region of Poyang Lake. The Xunwushui River flows into the Pearl River, whereas the region of Poyang Lake flows into the Yangtze River. The fish fauna and evolution of the fish fauna in Poyang Lake Basin owes much to geological events and belongs to the Oriental Region, South-east Asiatic sub-region and East China area. Anthropogenic activities including habitat alteration, overfishing, pollution and soil erosion have severely reduced the fish biodiversity in Poyang Lake Basin. River modifications (i.e. dam construction and sand excavation) and heavy metal pollution are the most significant threats to fish diversity and ecosystem functioning in the majority of the river systems in the province. To protect fish diversity and fisheries more effectively in Poyang Lake Basin, law enforcement should be strengthened, and the following measures could be introduced: restocking economically important fish species; establishing fish sanctuaries and freshwater protected areas, ordering a close season and developing sustainable aquaculture.     

Effects of experimentally enhanced flows on fishes of a small Texas (U.S.A.) stream: assessing the impact of interbasin transfer

1. Completion of a large interbasin water transfer system in northern Texas (U.S.A.) provided the opportunity to test the effects of pre-planned, experimental increases (≈×30) in flow on the fish fauna of a small, low-gradient, natural stream that was included as part of the conveyance system. Water from Lake Texoma (Red River basin) was pumped via a 16-km pipeline to the headwaters of Sister Grove Creek (Trinity River basin), which then carried the donor water 50 km downstream to Lake Lavon.
2. Baseline (pre-transfer) data on the composition of fish assemblages at seven stations on the creek or at its confluence with the receiving reservoir were collected monthly for 3 years, and similar data were collected for 2 years during and after trial flows of Lake Texoma water to Sister Grove Creek. We also documented fish abundance at five creek stations immediately before and after three trial flow periods of 10–14 days each in summer and autumn.
3. Multivariate analysis of all routine monthly samples over the 5-year pre- and post-transfer period showed moderate changes in the fish fauna of the creek after initiation of the trial flows. Samples taken within a week before and after the artificial high flows showed little overall change in abundance of individual fish species, but at some stations the quantitative or qualitative change in composition of the local assemblage was substantial.
4. The trial flows lasted 2 weeks or less. Long-term effects of water transfer on the fish fauna of Sister Grove Creek can only be determined after the conveyance system goes into normal operation, with periods of artificial flow of longer duration.     

Retention of suspended sediment and phosphorus on a freshwater delta, South Lake Tahoe, California

The Upper Truckee River and Trout Creek, two major tributaries inflowing to Lake Tahoe, join to form what was historically the largest wetland in the Sierra Nevada mountain range that separates California and Nevada (USA). In the 1950s the delta floodplain of the Upper Truckee River was greatly reduced in area (38%) by urban development and the diversion of the river into a single excavated channel. Conversely, Trout Creek still flows through a wide marsh system with significant overbank flooding before entering Lake Tahoe. This study hypothesized that river channel reaches that are not incised within the delta floodplain retain more sediment and nutrients as a result of greater floodplain connectivity, compared to more incised and excavated reaches. Suspended sediment (SS) and total phosphorus (TP) load data from the delta formed by the Upper Truckee River and Trout Creek were collected using flow stage sensors, turbidometers and depth-integrated samples. During the spring snowmelt flow events monitored in 2003, SS load was reduced by 13–41% for the Upper Truckee River and by 68–90% for Trout Creek. Similar reductions in TP load were observed: 13–32% for the Upper Truckee River and 61–84% for Trout Creek. Monitoring of Trout Creek indicated a reduction in load per unit volume of 20–34% in a moderately incised reach versus a reduction of 51–77% in a non-incised marsh reach containing lagoons, braided channels and backwater areas created by a beaver dam. Smaller particle sizes, <10 μm, were retained in the lower marsh reach with similar efficiencies as larger particle sizes. If retention rates from the Trout Creek portion of the marsh are applied to the Upper Truckee River, sediment loading to Lake Tahoe for 2003 would have been reduced by 917 tons of SS.     

太浦河大型底栖动物群落组成及时空分布特征

太浦河连接东太湖和黄浦江,是东太湖向下游行洪的主河道,也是黄浦江上游重要的引水水源。分别于2017年10月、12月和2018年3月、6月在太浦河沿程设置的5个站点开展了大型底栖动物季节频次的取样调研,分析了太浦河大型底栖动物群落的结构特征及其主要影响因子。调查期间共采集到大型底栖动物25种,隶属于3门6纲14科,其中以河蚬（Corbicula fluminea）为代表的双壳类和以铜锈环棱螺（Bellamya aeruginosa）为代表的腹足类处优势地位。太浦河大型底栖动物群落的密度、生物量及多样性特征在不同站点间均存在显著差异（P<0.05）;而在不同季节间均不存在显著差异（P>0.05）。聚类排序分析表明,太浦河大型底栖动物群落在空间上的差异较季节间的变化更为明显。太浦河大型底栖动物群落的物种组成特征与太浦河、东太湖的水文连通格局密切相关;而沿程不同程度人为干扰下的水体营养水平以及底质类型与生境异质性等生境条件对太浦河大型底栖动物群落的分布特征具有重要影响,其综合作用机理有待进一步研究。     

Effects of experimentally enhanced flows on fishes of a small Texas (U.S.A.) stream: assessing the impact of interbasin transfer

1. Completion of a large interbasin water transfer system in northern Texas (U.S.A.) provided the opportunity to test the effects of pre-planned, experimental increases (≈×30) in flow on the fish fauna of a small, low-gradient, natural stream that was included as part of the conveyance system. Water from Lake Texoma (Red River basin) was pumped via a 16-km pipeline to the headwaters of Sister Grove Creek (Trinity River basin), which then carried the donor water 50 km downstream to Lake Lavon.
2. Baseline (pre-transfer) data on the composition of fish assemblages at seven stations on the creek or at its confluence with the receiving reservoir were collected monthly for 3 years, and similar data were collected for 2 years during and after trial flows of Lake Texoma water to Sister Grove Creek. We also documented fish abundance at five creek stations immediately before and after three trial flow periods of 10–14 days each in summer and autumn.
3. Multivariate analysis of all routine monthly samples over the 5-year pre- and post-transfer period showed moderate changes in the fish fauna of the creek after initiation of the trial flows. Samples taken within a week before and after the artificial high flows showed little overall change in abundance of individual fish species, but at some stations the quantitative or qualitative change in composition of the local assemblage was substantial.
4. The trial flows lasted 2 weeks or less. Long-term effects of water transfer on the fish fauna of Sister Grove Creek can only be determined after the conveyance system goes into normal operation, with periods of artificial flow of longer duration.     

Risk assessment of heavy metals contamination in sediment and aquatic animals in downstream waters affected by historical gold extraction in Northeast China

To assess the risk of heavy metals contamination on the aquatic ecosystem in downstream waters of a gold field in Northeast China, samples of sediment, fish, shrimp, and mussels were collected to determine heavy metals concentrations. According to I_geo, more attention should be given to Hg, Pb, and Cu pollution in sediment of Weisha River. For aquatic animals, the greatest contents of Hg, Cu, and Pb were found in samples collected from Weisha River, while the maximum values of Zn, Cd, and Cr were found in Hongshi Reservoir, Banmiao River, and Songhua Lake, respectively. The Hg and Pb contents in fish were found in the order of predatory fish > omnivorous fish > herbivorous fish, although for other metals no significant difference was observed among the three trophic levels. The contents of metals in Oriental river prawn and Chinese pond mussel were greater than that in fish, except for Pb. The Target Hazard Quotient and Hazard Index of metals showed that the Carnivorous and Omnivorous fish from Songhua Lake and Hongshi Reservoir, as well as all fish from Banmiao River and Weisha River, were not suitable for consuming in the view of the combined risk of all metals.     

南四湖典型入湖河流沉积物重金属污染特征与风险评价研究

以南四湖两条典型入湖河流为研究对象,分别对湖东的泗河及湖西的东鱼河沉积物中9种重金属(Cr、Ni、Zn、Cu、Pb、Hg、Cd、As、Mn)含量进行分析,最后采用多种方法解析重金属的来源并对其污染特征和生态风险进行评价.结果表明,两条河流沉积物中重金属均存在一定程度的富集,尤其是Hg、Zn、Cd富集最严重.泗河沉积物中...     

Assessing trout farm pollution by biological metrics and indices based on aquatic macrophytes and benthic macroinvertebrates: A case study

In this study we examine the ecological responses of aquatic macrophytes and benthic macroinvertebrates to a trout farm effluent located in the upper Tajuña River (Guadalajara province, Central Spain), comparing the suitability of biological metrics and indices based on these two communities to assess trout farm pollution in the upper reaches of fluvial ecosystems. Sampling surveys were carried out in winter and summer 2006, and in spring 2007. Four sampling sites were selected along the study reach: S-1, placed upstream from the trout farm, was used as a reference station; S-2, S-3 and S-4 were placed about 10, 100 and 1000 m downstream from the trout farm outlet, respectively. The stream bottom was mainly stony with cobbles and pebbles at all sampling sites, except at S-2 where it was covered by a thick layer of organic sediment. Aquatic macrophytes and benthic macroinvertebrates significantly increased in abundance downstream from the trout farm effluent, particularly at S-3 and S-4. However, while the diversity of aquatic macrophytes increased downstream (at S-3 and S-4, but not at S-2), the diversity of benthic macroinvertebrates significantly decreased, particularly at S-2. Regarding aquatic macrophytes, moss coverage values, as well as values of the Index of Macrophytes (IM) and the Macroscopic Aquatic Vegetation Index (MAVI), were higher at S-1 than at S-2. In contrast, values of moss coverage and IM were significantly lower at S-1 than at S-3 and S-4. MAVI values were similar at S-1, S-3 and S-4. Regarding benthic macroinvertebrates, the abundance percentage of oligochaetes and chironomids (expressed as OC%) was significantly higher at downstream polluted sites (particularly at S-2) than at S-1. Conversely, the abundance percentage of ephemeropterans, plecopterans and trichopterans (expressed as EPT%), and scores of the total Biological Monitoring Water Quality (t-BMWQ) index and the average Biological Monitoring Water Quality (a-BMWQ) index were much lower at S-2 than at S-1, with a clear tendency to increase with increasing downstream distance from the trout farm. Correlation analyses showed that changes in physicochemical parameters (inorganic nutrients, dissolved oxygen and turbidity) along the study reach were better correlated with changes in metrics and indices based on benthic macroinvertebrates. Overall it is concluded that metrics and indices based on benthic macroinvertebrates (such as OC% and EPT% metrics and t-BMWQ and a-BMWQ indices) can be more suitable than those based on aquatic macrophytes for the biological monitoring of trout farm pollution in the upper reaches of fluvial ecosystems, since the higher diversity of benthic macroinvertebrates inhabiting the river bottom would permit this community to exhibit a better indicator performance regarding the environmental stress caused by trout farm effluents. However, further studies are needed in order to generalize this conclusion.     

深圳大鹏半岛主要河流底栖动物群落结构及水质生物学评价

2013年5月对深圳大鹏半岛4条主要河流(葵涌河、王母河、鹏城河和东涌河)的大型底栖动物群落结构进行了调查,并利用香农-维纳多样性指数和生物指数(BI)对河流水质进行了生物学评价。在大鹏半岛主要河流的15个样点共采获大型底栖动物35种,隶属3门7纲21科,其中水生昆虫26种,约占底栖动物种类数的74%。但底栖动物的种类组成与分布极不均匀,EPT(蜉蝣目+襀翅目+毛翅目)等对水质变化较敏感的类群主要分布于葵涌河的源头及受人为干扰活动较少的东涌河,而耐污能力较强的摇蚊科幼虫、霍甫水丝蚓和颤蚓等则为葵涌河中、下游样点、王母河和鹏城河的优势物种。生物指数(BI)相较于香农-维纳多样性指数,更适用于水质评价。结果显示,除葵涌河源头、鹏城河和东涌河样点的水质处于清洁至轻污染外,其余大部分样点处于中污染至重污染状态。推测大鹏半岛的王母河及葵涌河中、下游河段的生活污水及工业废水已对底栖动物的群落结构与河流水质造成了一定的影响。     

The impact of an industrially contaminated lake on heavy metal levels in its effluent stream

Levels of cadmium and zinc in various components of Williamson Ditch (an industrially contaminated stream flowing into Palestine Lake), Trimble Creek (a stream draining Palestine Lake) and the Tippecance River (a river receiving Trimble Creek) were determined. Water, sediment, plant, fish and clam samples were analyzed for cadmium and zinc content by atomic absorption spectrophotometry. Unweighted mean metal concentrations in Trimble Creek were the following: water, 51 µg Zn/1 and 4.2 µg Cd/1; sediment, 592 µg Zn/g and 48.8,µg Cd/g; plants, 375 µm Zn/g and 7.91 µg Cd/g; fish, 145 µg Zn/g and 6.02 µg Cd/g. These concentrations were generally lower than those found in Williamson Ditch and higher than those found in the Tippecanoe River or background levels previously reported for other aquatic ecosystems.     

硫铁矿酸性矿山废水对大型底栖动物群落结构的影响

2006年11月和2007年1月通过金属和生物指标的量化监测,就酸性矿山废水对大型底栖动物群落结构的影响及高岚河污染现状进行研究。典型对应分析表明：酸性废水对高岚河上游大型底栖动物群落结构影响最大。对高岚河大型底栖动物群落结构和功能摄食类群进行分析,研究硫铁矿酸性矿山废水对河流大型底栖动物群落的影响,结果表明：高岚河自矿源起约16km河段,大型底栖动物群落结构已经遭到严重破坏;多足摇蚊Polypedilum tritum和真凯氏摇蚊Eukiefferiellab rehmi对酸和金属均具有较强的耐受力;捕食者和刮食者对矿山酸性废水带来的污染反应最为敏感。逐步回归分析表明：大型底栖动物生物多样性受Al、Ca、Cd、Fe、Mg、Mn等金属影响最大;密度受Ca、Cr和Mg的影响最大。     

滆湖入湖河流春季大型底栖动物群落结构及水质生物学评价

分别于2018年4月和2019年4月对滆湖入湖河流底栖动物开展调查,并利用生物指数对水质进行生物学评价。结果表明:共鉴定滆湖入湖河流底栖动物28种,以重度耐污种霍甫水丝蚓(优势度为0.46)和中等耐污种铜锈环棱螺(优势度为0.11)占据绝对优势。生物多样性方面以鹤溪河最高,湟里河、扁担河次之,夏溪河及入湖河口最低,水生植物分布是影响各区域底栖动物多样性的重要因素。卡尔森营养状态指数(TSI)与水质污染等级生物评价结果基本一致,以新孟河延伸拓浚工程沿线为界,鹤溪河、夏溪河、湟里河中上游河段处于中度富营养化水平,水体为轻-中污染状态,而下游河段、扁担河及入湖河口处于重度富营养化水平,水体为中-重污染状态。     

Stream Macroinvertebrate Community Affected by Point‐Source Metal Pollution

The impacts of mining activities on aquatic biota have been documented in many stream ecosystems. In mining streams, point‐source heavy metal pollution often appears in the stream. We hypothesize that this pollution is toxic to macroinvertebrates owing to high concentrations of metals and therefore affects macroinvertebrate community structure. We investigated macroinvertebrate community structure in mountain streams, including heavy metal‐polluted sites and neutral‐pH streams, to determine the relationship between community structure and environmental factors such as low pH and heavy metal concentrations. Based on multidimensional scaling ordination, the macroinvertebrate community at heavy metal pollution sites was remarkably different from that at the other sites. Inductively coupled plasma mass spectrometry revealed high concentrations of aluminum and iron in surface water at the polluted sites. Macroinvertebrate community structure at the metal pollution sites was significantly different from that at other sites in the same stream and in neutral‐pH streams. Thus, point‐source metal pollution may reduce the density and diversity of in situ macroinvertebrates. (© 2007 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)     

鄱阳湖主要入湖段典型底栖动物体内微塑料累积特征

以鄱阳湖-饶河和鄱阳湖-赣江中支两个主要入湖段典型底栖动物(河蚬、圆顶珠蚌、中国圆田螺)为对象,通过组织消解、滤膜过滤分离和显微镜检筛分微塑料(粒径<5mm),分析底栖动物体内微塑料的累积特征。结果表明:三种底栖动物体内均有微塑料淀积且主要淀积于消化道组织中,不同物种淀积丰度表现为河蚬>中国圆田螺>圆顶珠蚌;淀积的微塑料类型包括颗粒类、碎片类、薄膜类和纤维类,其中以纤维类为主;微塑料颜色主要有透明、蓝、红、紫;粒径以<1 mm的丰度最高,且随粒径增大丰度呈递减的趋势;空间尺度上,饶河入湖段底栖动物体内微塑料丰度高于赣江中支入湖段。本研究表明,鄱阳湖微塑料污染已造成底栖动物体内微塑料的累积,湖水产品的食用需要谨慎,但与国内外其他研究相比,本次研究区域的底栖动物处于中等微塑料污染。     

Pollution of a Tasmanian River by Mine Effluents. II. Distribution of Macroinvertebrates

The distribution and abundance of macroinvertebrates were studied in the South Esk River, Tasmania; a river subject to cadmium and zinc pollution as a result of mining. The groups most intolerant of cadmium-zinc pollution were the Crustacea, Mollusca and Annelida. Highly tolerant groups included aquatic Hemiptera and Arachnida, and larvae of leptocerid trichopterans. A drop in both species diversity and abundance occurred after floods in winter and was probably due to pulses of cadmium and zinc down the river and also to increased molar action of the unstable substrate.     

广东横石水河大型底栖动物群落与环境因子的关系

应用典范对应分析(CCA)对横石水河流域14个样点中的大型底栖动物与环境因子的关系进行了研究。结果表明,枯水期和丰水期的物种与环境因子的相关性均在90%以上,说明大型底栖动物在横石水河的分布很大程度上受到环境因子的影响。化学需氧量(COD)和pH值是影响枯水期大型底栖动物分布的两个主要因子,浊度和重金属Cu、Pb浓度对大型底栖动物分布也有一定程度的影响。在丰水期,重金属Cu、Pb浓度和pH值是影响大型底栖动物分布的关键因子。从种类水平看,耐污种类如蠓类、摇蚊和大蚊的丰富度与COD和重金属浓度的环境轴呈正相关,而敏感种类如腹足纲、毛翅目以及蜉蝣目昆虫与COD和重金属浓度的环境轴呈负相关。     

山地河流潜流层大型无脊椎动物群落组成及分布

潜流层大型无脊椎动物是河流生态系统重要的组成部分.2013年8月(夏季)、12月(冬季)和2014年4月(春季),在黑水滩河上游河段,采用人工基质法调查潜流层大型无脊椎动物.结果表明: 3个季节共采集大型无脊椎动物27种,其中夏季22种、冬季和春季各16种,各季节水生昆虫种类所占比例均较高,分别为81.8%、75.0%和62.5%;夏季群落密度显著低于冬季和春季,春季最高;冬季群落生物量显著高于夏季和春季,夏季最低;3个季节群落的物种丰富度指数、Shannon多样性指数和Pielou均匀度指数均没有显著性差异.空间分布上,大型无脊椎动物的密度和丰富度均随潜流层深度增加而呈现降低的趋势,大多数个体均分布在0～20 cm深度.群落以滤食者和收集者组成的集食者为绝对优势功能群.动物的相互作用、生活史策略和潜流层的理化条件影响着潜流层大型无脊椎动物的群落结构和时空分布.     

Periphyton responses to invertebrate grazing and riparian canopy in three northern California coastal streams

SUMMARY. 1. Field experiments were conducted to examine the impact of grazing invertebrates on periphyton biomass in twenty-one pools across three northern California coastal streams (U.S.A.): Big Sulphur Creek, the Rice Fork of the Eel River, and Big Canyon Creek. Periphyton accrual on artificial substrate tiles was compared in each stream between two treatments: those elevated slightly above the stream bottom to reduce access by grazers (= platforms) and those placed directly on the stream bottom to allow access by grazers (=controls).
2. Crawling invertebrate grazers (cased caddisflies and snails) were numerically dominant in each stream (86% of all grazers in Big Sulphur Creek, 61% in the Rice Fork, 84% in Big Canyon Creek). Platforms effectively excluded crawling grazers, but were less effective in excluding swimming mayfly grazers (Baetidae).
3. Periphyton biomass (as AFDM) on tiles was significantly lower on controls compared to platforms for the Rice Fork, an open-canopy stream, and Big Sulphur Creek, a stream with a heterogeneous canopy. In contrast, no grazer impact was found for Big Canyon Creek, a densely shaded stream. Here, extremely low periphyton biomass occurred for both treatments throughout the 60 day study.
4. The influence of riparian canopy on periphyton growth (i.e. accrual on platforms), grazer impact on periphyton, and grazer abundance was examined for Big Sulphur Creek. As canopy increased (15–98% cover), periphyton biomass on platforms decreased. In contrast, canopy had little influence on periphyton accrual on controls; apparently, grazers could maintain low periphyton standing crops across the full range of canopy levels. The abundance of one grazer species, the caddisfly Gumaga nigricula , was highest in open, sunlit stream pools; abundance of two other prominent grazers, Helicopsyche borealis (Trichoptera) and Centroptilum convexum (Ephemeroptera), however, was unrelated to canopy.     

Assessing structural and functional ecosystem condition using leaf breakdown: studies on a polluted river

1. Leaf breakdown rates of Alnus glutinosa were determined and the structure of decomposer assemblages associated with leaves were analysed to assess the effect of pollution on the ecological condition of the Ave River (North‐west Portugal). 2. Increase in organic and inorganic nutrients was associated with an increase in density and a decrease in richness of macroinvertebrates, a dramatic decline in the conidial production of aquatic hyphomycetes, but no major change in the richness of aquatic hyphomycetes. 3. Downstream nutrient enrichment was correlated with accelerated leaf breakdown rates. 4. The degree of functional impairment assessed by the ratio of leaf breakdown rates in coarse‐mesh and fine‐mesh bags was in accordance with the gradient of pollution defined by two biotic indices. 5. This study supports the contention that leaf breakdown experiments are a valuable tool to assess the effect of pollution on the ecological condition of rivers.