基于大型底栖无脊椎动物完整性指数的鄱阳湖湿地生态健康评价

湿地生态健康评价对于掌握湿地的健康状况、理解人类活动干扰对其影响及实施生态预警等有重要意义。鄱阳湖对于维持其流域甚至长江中下游的生态平衡十分重要,目前尚未建立起其较完善的生态健康评价指标体系。大型底栖无脊椎动物完整性指数(benthic macroinvertebrate-based index of biotic integrity, B-IBI)是广泛应用的湿地生态健康评价方法。基于30个采样点(7个参照点,23个受损点)的大型底栖无脊椎动物采样数据,构建鄱阳湖湿地的B-IBI指数,采用自然断点法划分非常健康、健康、一般、差和极差5个健康等级标准,据此评价湿地生态健康状况。研究表明:(1)基于B-IBI指数的鄱阳湖湿地生态健康评价结果为一般;(2)就采样点B-IBI分值而言,呈现出西部健康状况优于东部的格局,其中国家级自然保护区内状况较好,而工业区、城镇、农田及河流入湖口附近状况较差;(3)B-IBI指数与前期构建的景观发展强度指数(LDI)、栖息地环境质量指数(QHEI)以及植被完整性指数(V-IBI)具有显著相关性,表明基于不同指数的评价结果较为一致。本研究构建的B-IBI指数能为鄱阳湖湿地的生态健康评价和监测提供重要方法。     

Benthic fauna in a series of lakes displaying a gradient of pH

The benthic fauna was examined in a series of four isolated headwater lakes, displaying a pH gradient of 5.4–7.0. A slight reduction in number of taxa present occurred below pH 6, with the fauna below 3 m dominated by the Diptera. Although epibenthic gastropods were rare, in contrast with European studies, Amphipoda, Ephemeroptera and Pisidium were common in the least buffered lake, which experiences spring pH values as low as 4.7. There were little relation between the pH or alkalinity, and the abundance, and biomass of the fauna at depths greater than 3 m. However, biomass of the littoral fauna increased significantly in the lakes with lower pH, as a result of an increase in large littoral species normally susceptible to fish predation.     

Seasonal changes in the digestive enzyme levels of the amphipod Corophium volutator (Pallas) in relation to diet

The diet of the amphipod Corophium volutator (Pallas) living on extensive intertidal mud flats in the Bay of Fundy, eastern Canada, was investigated by direct and indirect methods. Microscopic observation of gut contents revealed macrophyte detritus but few diatom frustules. Laboratory cultures showed good survival on a diet of benthic diatoms, while on a diet of Spartina detritus survival was poor, although significantly better than the survival of starved animals. The ratios of gut enzyme activities, amylase to protease and amylase to laminarinase, changed markedly with the season. In summer the ratio was similar to that of animals cultured on a diet of benthic diatoms; in spring it resembled that of animals cultured on Spartina detritus, while in winter it was similar to that of starved animals. It is concluded that in summer, rapid growth is made possible by feeding on benthic diatoms, while Spartina detritus is an inferior food source which aids survival at other times of the year.     

应用鱼类完整性评价体系评价辽河流域健康

根据2009年8月辽河流域33个站点采集的鱼类数据(参照点8个,观测点25个),通过参数指标值分布范围、相关关系和判别能力分析,从23个侯选指标中筛选出了辽河流域的鱼类完整性指数(F-IBI)构成指标体系。该体系包括鱼类总种类数、Shannon-Wiener多样性指数、中上层鱼类百分比、底层鱼类百分比、鱼类个体总数、杂食性鱼类百分比、耐受性鱼类百分比、敏感性鱼类百分比和产粘性卵鱼类百分比共9个生物参数。分别采用1、3、5赋值法和比值法计算各站点的IBI分值,并根据参照点IBI分值的25%分位数值确定健康等级标准,对小于25%分位数值的分布范围进行3等分,提出了辽河流域河流鱼类完整性评价标准,分为健康、一般、差、较差4个等级。两种方法评价结果虽不完全相同,但趋势基本一致。Pearson相关分析表明IBI值与生境状况、水质状况、栖息地环境质量显著相关,其中与海拔、栖息地评分呈显著正相关,与CODCr、氯化物、总溶解颗粒物、含沙量、硬度、电导率呈显著负相关。     

梯级水坝运行对漫湾库区底栖动物群落结构及分布格局的影响

底栖动物是对水生态系统退化和生境条件改变最为敏感的生物类群之一,同时也是开展梯级水坝水生态系统变化和演替研究的指示生物.本研究以国际生物多样性保护及水电梯级开发生态影响研究的热点地区澜沧江中下游为例,以澜沧江干流兴建的第一座水坝漫湾库区为研究区域,分别于2011和2016年开展底栖动物定点采样,并结合其蓄水前(自然河段,1996年)和单级水坝蓄水初期(1997年)的历史调研数据,全面分析了梯级水坝运行前后漫湾库区底栖动物群落的结构、分布格局及演变趋势.结果表明: 漫湾库区底栖动物群落的优势种组成逐渐由寡毛纲和昆虫纲种类演变为软体动物门类占绝对优势;沿库区生境的纵向梯度变化,底栖动物密度和生物量均表现为升高的趋势,而静水区增加更为显著;对底栖动物功能摄食群的分析表明,静水区由掠食者和收集者占优势演变为滤食者类占绝对优势;梯级水坝运行后,采用生物指数评价结果表明,2016年库区综合水质指标明显优于2011年.漫湾库区底栖动物群落的演变与上游梯级小湾水坝的调度运行及库区的水文状况和泥沙淤积情况密切相关,并随着梯级水坝的运行处于动态变化之中.     

Developing a Benthic Index of Biological Integrity and Some Relationships to Environmental Factors in the Subtropical Xiangxi River,China

The aim of this study is to develop a benthic index of biotic integrity (B‐IBI) to help understand how the increasing anthropogenic pressure may impact the subtropical Xiangxi River in China. Benthic macroinvertebrate and environmental surveys were conducted at 77 sites in early summer 2004. Each collection site was categorized as reference or impaired based on physical, chemical, biological, and land‐use information. Six non‐redundant metrics from 35 metrics were used to differentiate between reference and impaired sites. We selected six metrics for the final IBI. The scoring criteria of each metric were normalized based on the quadrisection and 0–10 scaling systems. Both scaling methods were used to assess the aquatic health of each site in the Xiangxi River watershed. The results showed that most sites were in fairly poor condition. Furthermore, we identified the relationship between B‐IBI metrics, water‐quality, and land‐use variables with a principal component analysis. A composite of nutrients and land‐use intensity explained most variances. These results suggest that the B‐IBI may be a suitable method for assessing river conditions within the subtropical Xiangxi River in central China (© 2010 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)     

The Distribution of Polychaete Feeding Guilds in Organic Enriched Sediments of San Vicente Bay,Central Chile

The benthic macroinfauna (>500 μm) of San Vicente Bay, Central Chile (36°44′S; 73°09′W) was studied at 8 sublittoral stations along a 6.5 km length transect from the San Vicente fishery harbor out to the open sea, during October 1991, January 1992 and October 1992. Structural changes of the benthic macroinfauna were evaluated a) functionally in terms of polychaete trophic guilds, and b) numerical classification and ecological ordination. Multivariate analysis was used to explore polychaete fedding guild responses to environmental variables. The principal objective of the study was to test whether changes in functional groups (within and between stations) are related to perturbation induced by anthropogenic organic enrichment, or are a consequence of natural environmental fluctuations. Trophic guilds of polychaetes associated with the sandy environment of the bay, showed a clear seasonal dominance of carnivores during the spring 1991–1992 and of surface suspension - deposit feeders, sessiles or discretely motile and tentacled polychaetes (F-SD-SDT, see Annex) in summer 1992. This guild distribution could be due to the sediment stability and a greater niche diversification in the more sandy stations. However, there were only a few significant relationships between trophic guilds and total organic matter and silt-clay fraction. This limits the utility of the guilds as indicators of perturbations induced by organic enrichment. Over 95% of the variation in the guild data was explained by environmental factors such as water depth, station distance from the harbor, silt-clay, sand, grain size and organic matter content. The comparison between reported faunistic and sedimentary data and the data obtained in this study, suggests that there is an increase of the organic enrichment of the sediments in the most inner area of this embayment. However, there is no evidence of this being directly responsible for the polychaete feeding guild distribution of San Vicente Bay.     

大型底栖无脊椎动物对溪流中三角枫落叶分解的影响

采用复合网袋法,研究了冬季南京紫金山三角枫落叶在无干扰溪流和生态恢复溪流中的分解过程.结果表明：112 d后,三角枫落叶无灰干质量剩余率为31％～62％,分解速率符合指数衰减模型(P<0.05).在生态恢复溪流和无干扰溪流的流水生境中, 三角枫落叶的分解速率分别为0.0030 d^-1和0.0064 d^-1,静水生境中分别为0.0018 d^-1和0.0016 d^-1.流水生境中,无干扰溪流网袋内的大型底栖动物多度和生物量显著高于恢复溪流(P<0.05),而静水中无显著差异(P>0.05).无干扰溪流中的撕食者多度比例最高(70.4%),以栉水虱为主;生态恢复溪流中滤食者的多度比例最高(37.8%),以长跗摇蚊属为主.流水生境中三角枫落叶的分解速率与撕食者物种丰富度和多度相关性显著(P<0.01),而与生物量的相关性不显著(P>0.05).说明冬季溪流中撕食者的物种丰富度和多度决定三角枫落叶的分解速率.     

The Need for Multiple Lines of Evidence for Predicting Site-Specific Ecological Effects

The goal of this paper is to illustrate the value and importance of the “weight of evidence” approach (use of multiple lines of evidence from field and laboratory data) to assess the occurrence or absence of ecological impairment in the aquatic environment. Single species toxicity tests, microcosms, and community metric approaches such as the Index of Biotic Integrity (IBI) are discussed. Single species toxicity tests or other single lines of evidence are valuable first tier assessments that should be used as screening tools to identify potentially toxic conditions in a effluent or the ambient environment but these tests should not be used as the final quantitative indicator of absolute ecological impairment that may result in regulatory action. Both false positive and false negative predictions of ecological effects can occur due to the inherent variability of measurement endpoints such as survival, growth and reproduction used in single species toxicity tests. A comparison of single species ambient toxicity test results with field data showed that false positives are common and likely related to experimental variability or toxicity to selected test species without measureable effects on the ecosystem. Results from microcosm studies have consistently demonstrated that chemical exposures exceeding the acute or chronic toxicity concentrations for highly sensitive species may cause little or no ecologically significant damage to an aquatic ecosystem. Sources of uncertainty identified when extrapolating from single species tests to ecological effects were: variability in individual response to pesticide exposure; variation among species in sensitivity to pesticides; effects of time varying and repeated exposures; and extrapolation from individual to population-level endpoints. Data sets from the Chesapeake Bay area (Maryland) were used to show the importance of using “multiple lines of evidence” when assessing biological impact due to conflicting results reported from ambient water column and sediment toxicity tests and biological indices (benthic and fish IBIs). Results from water column and sediment toxicity tests with multiple species in tidal areas showed that no single species was consistently the most sensitive. There was also a high degree of disagreement between benthic and fish IBI data for the various stations. The lack of agreement for these biological community indices is not surprising due to the differences in exposure among habitats occupied by these different taxonomic assemblages. Data from a fish IBI, benthic IBI and Maryland Physical Habitat Index (MPHI) were compared for approximately 1100 first through third-order Maryland non-tidal streams to show the complexity of data interpretation and the incidence of conflicting lines of evidence. A key finding from this non-tidal data set was the need for using more than one biological indicator to increase the discriminatory power of identifying impaired streams and reduce the possibility of “false negative results”. Based on historical data, temporal variability associated with an IBI in undisturbed areas was reported to be lower than the variability associated with single species toxicity tests.     

Changes in diatom-dominated biofilms during simulated improvements in water quality: implications for diatom-based monitoring in rivers

Although benthic diatoms are used to assess river water quality, there are few data on the rate at which diatom assemblages react to changes in water quality. The aim of this study was to assess the reaction time of diatoms and to discuss the changes occurring during water quality improvement on the basis of their autecological characteristics. In order to simulate this improvement, diatom-dominated biofilms grown on artificial sandstone substrata were transferred from several polluted rivers to an unpolluted river. They were sampled three times: before transfer and 1 and 2 months after transfer. The ecology and growth-forms of the taxa explained most of the changes in species composition observed during the experiment. Adnate diatoms gradually replaced motile and stalked taxa. Gomphonema parvulum, a stalked diatom positioned vertically in the biofilm, is adapted for light and space competition in high-density algal biofilms. When transferred to an unpolluted site, this growth-form is less competitive and does not tolerate the high grazing pressure. Fistulifera saprophila is a single celled motile diatom, living in organic matrices. When the artificial substrata were transferred to the unpolluted site, this particular ecological niche disappeared quickly. On the other hand, Achnanthidium minutissimum, which is considered to be cosmopolitan and an early colonizer, increased during the first month of transfer and then decreased. It was gradually replaced by A. biasolettianum, which was the taxon best suited to this pristine stream. The changes observed differed between treatments depending on the species composition and architecture of the biofilms. In particular, biofilms dominated by stalked and motile diatoms were more quickly modified than those dominated by small motile diatoms. The diatom index reflects these changes, and its values showed that about 60 days following a water quality improvement were necessary for transferred diatom assemblages to reach diatom index values similar as those at the unpolluted river.     

Validation of a fish-based index of biotic integrity for streams and rivers of central Mexico

An existing version of a fish assemblage-basedindex of biotic integrity (IBI) for the streamsand rivers of west central Mexico was testedwith independent data to validate itsusefulness as a measure of ecosystem qualityand to determine the geographic area where itis effective. Fish assemblages from 63 uplandsites in 10 basins in central Mexico(Armería, Ameca, Coahuayana, Marabasco,Purificación, Grande de Morelia, Grande deSantiago, Lerma, Balsas and Pánuco) wereassessed using the metrics and scoring criteriafrom the existing IBI and then compared withindependent evaluations of habitat and waterquality. IBI scores were congruent withhabitat and water quality values in theArmería, Purificación and Marabascobasins, where the IBI was first developed, aswell as in the adjacent Ameca and Coahuayanabasins. We conclude that the IBI can be usedwithout modification to assess environmentalquality in non-coastal streams and riverswithin these five basins. Further data areneeded from the Grande de Morelia, Grande deSantiago and middle Lerma basins, but ourresults suggest that the existing IBI may alsobe effective here. However, the existing IBIdoes not consistently reflect habitat and waterquality conditions in the Balsas and Pánucobasins and must be modified before it can beapplied there. Necessary modifications in theBalsas basin appear to be small and relatedprimarily to changes in the scoring criteriafor metrics. However, in the Pánuco basinmore substantive changes in the nature of themetrics are required. Changes in the IBI forthese basins are proposed. The IBI is nowvalidated for use in river monitoring,conservation and restoration efforts in 5basins in west central Mexico and suggestionsfor its application in other basins areavailable here.     

基于底栖动物预测模型构建生物完整性指数评价河流健康

提高生物完整性指数(integrity of biotic index,IBI; 又称多参数指数multi-metric index, MMI)在时间和空间尺度的稳定性是水生态完整性评价和水环境管理实践的重要内容.本研究利用2004—2011年在浙江省多个河流采集的227个点位的底栖动物和水质理化数据,利用地理信息系统(GIS)提取样点及其对应流域的自然预测因子(如地理形态学、气候学)和土地利用数据,通过随机森林模型方法定量时间和空间尺度自然变量对生物群落的影响,构建基于预测模型控制自然因子影响方法和常规方法的MMI,并比较它们的表现力.结果表明: 基于预测模型法和基于常规方法构建的MMI的核心组成参数存在差异,随机森林模型中自然预测因子对预测模型MMI构成生物参数的解释量介于11.4%～61.2%.预测模型方法提高了MMI的精确度和准确度,但其敏感性和响应性低于常规方法的MMI.最近距离方法表明,9个评价点位和1个严重受损点位的自然属性与参照点位的自然属性存在差异性.在计算参照点位自然属性代表性范围的基础上,采用预测模型方法控制自然变量可以提高MMI的精确度和准确度,同时降低评价结果出现Ⅰ型(将健康水体误判为受损水体)或者Ⅱ型(将受损水体误判为健康水体)错误的可能性.研究结果可以为提高完整性指数评价稳定性和表现力提供方法支持.     

基于大型底栖动物完整性指数的伊犁河健康评价及其对时间尺度变化的响应

大型底栖动物完整性指数（Benthic index of biotic integrity, B-IBI）是广泛应用的河流生态健康评价方法,然而从时间尺度（月份、年际变化）上评价B-IBI适用性的研究较少。有鉴于此,于2013-2015年期间,每年在5月、7月、8月和10月分别对新疆伊犁河大型底栖动物群落结构进行系统调查,并构建底栖动物完整性指数,评价河流水体的健康状况,同时评价其在时间尺度上的影响。非度量多维尺度分析（Non-metric multidimensional scaling, NMDS）显示,伊犁河不同月份的大型底栖动物群落结构相似度较高。通过对群落丰富度、种类个体相对丰度、功能摄食群、耐污能力、小生境质量和生物多样性指数等6个大类共计30个候选参数进行筛选,选取EPT（蜉蝣目、襀翅目、毛翅目）分类单元数、蜉蝣目个体相对丰度、耐污类群的个体相对丰度、生物指数（Biotic index, BI）以及黏附者个体相对丰度为伊犁河流域B-IBI健康评价体系的核心指标。B-IBI的评价等级为：B-IBI>3.38为健康,2.53-3.38为亚健康,1.69-2.53为一般,0.84-1.69为差,B-IBI值≤0.84为极差。结果显示,伊犁河8个典型样点中,6个采样点健康状况为健康或者亚健康,2个采样点为一般。总体上伊犁河健康状况较好,其中支流巩乃斯河和喀什河的健康状况要好于伊犁河干流和支流特克斯河。不同月份的B-IBI值无显著性差异（P>0.05）,表明伊犁河流域整体健康状况不受季节变化的重要影响。2013年与2015年B-IBI值差异显著（P<0.05）,伊犁河健康状况存在逐年变好的趋势,河流的生物健康评价需要开展长期的监测才能较全面的反映河流健康状况。参照点整体上的B-IBI值显著高于受损点的B-IBI值,表明B-IBI健康评价体系在伊犁河流域的良好适用性。该研究将从时间尺度上为基于B-IBI的河流健康评价方法提供理论参考。     

Individual and combined effects of fish predation and bed disturbance on stream benthic communities: a streamside channel experiment

1. The composition and spatiotemporal dynamics of biological communities are influenced by biotic processes, such as predation and competition, but also by physical disturbances, such as floods in running waters. However, the interplay of disturbance with predation is still poorly understood, especially in frequently disturbed streams. Further, different predator species can affect prey communities in different ways depending on their feeding mode and efficiency. 2. We investigated the individual and combined effects of flood‐induced bed disturbance and fish predation on the benthos for 4 weeks in 18 streamside channels fed by a flood‐prone New Zealand river. Bed movements caused by floods were simulated by tumbling the substratum in half the channels. Six channels each were stocked with introduced brown trout (Salmo trutta) or native upland bully (Gobiomorphus breviceps) or had fish excluded. We studied algal biomass and both invertebrate density and daytime activity on surface stones on several dates after the disturbance, invertebrate community composition in the substrata of the entire channels on day 28 and leaf decomposition rates over the 28‐day period. 3. Disturbance affected algal biomass and density, richness and activity of surface stone invertebrates, and overall density and richness of channel invertebrates. Presence or absence of fish, by contrast, did not influence overall invertebrate standing stocks when subsurface substrata were included but did affect invertebrate densities on surface stones in 45% of all analysed cases and invertebrate activity on surface stones in all cases. Leaf decomposition rates were not influenced at all by the experimental manipulations. 4. Native upland bullies featured more often than exotic brown trout in causing invertebrate density changes and equally often in causing changes to grazer behaviour. Overall, our results imply that fish predation can have strong effects on the benthic invertebrate community in frequently disturbed streams, especially via behavioural changes.     

Observations on feeding in a South African suctorial hoplonemertean, Nipponnemertes sp. (Family Cratenemertidae)

Marine hoplonemerteans were collected intertidally inAlgoa Bay, Port Elizabeth, South Africa in 1983.Algoa Living worms appear to belong to the genus Nipponnemertes, perhaps N. africanus (Wheeler, 1940). The external morphology and thestylet apparatus are described and illustrated. Laboratory observations showed that this speciesattacked and consumed two species of sympatricamphipods, Elasmopus pectenicrus and Hyalegrandicornis (the only two species tested). Thefeeding behavior was similar to that documented forother suctorial nemerteans that feed on amphipods. Onecomplete feeding sequence, from the initial strike tocompletion of feeding on H. grandicornis,took approximately 12 min: the proboscis struck theventral side of the amphipod, which was immobilized in<1 min; the head eventually wedged between thesternal plates, and the internal organs were evacuatedby suctorial action. The addition of E. pectenicrus andH. grandicornis as potentialprey for suctorial hoplonemerteans brings the totalknown number of amphipod species to 25, involving atleast ten families. A summary of all species ofAmphipoda known to be potential prey for suctorialhoplonemerteans is presented.     

Biodiversity and functioning of polychaetes in benthic sediments

Polychaetes are well represented in most marine and estuarine environments, both in terms of number of individuals and species, and they typically contribute a significant percentage of the total macrofaunal diversity. They exhibit considerable variations in recruitment in both time and space, which is then often reflected in adult distributions. Whilst families and genera of polychaetes have wide distributions, normally species have discrete distributions. Polychaetes are often classified according to their diverse feeding guilds. They play a major role in the functioning of benthic communities, in terms of recycling and reworking of benthic sediments, bioturbating sediments and in the burial of organic matter. Some species form dense tubiculous colonies which can radically change recruitment patterns of other infaunal organisms. Polychaetes, by their burrowing and feeding activity, may considerably enhance various sedimentary processes. However, much remains to be learnt as to how benthic communities function, and how they may change in function as they are increasingly being impacted especially in coastal waters adjacent to centres of population.     

Predicting the cover and richness of intertidal macroalgae in remote areas: a case study in the Antarctic Peninsula

Antarctica is an iconic region for scientific explorations as it is remote and a critical component of the global climate system. Recent climate change causes a dramatic retreat of ice in Antarctica with associated impacts to its coastal ecosystem. These anthropogenic impacts have a potential to increase habitat availability for Antarctic intertidal assemblages. Assessing the extent and ecological consequences of these changes requires us to develop accurate biotic baselines and quantitative predictive tools. In this study, we demonstrated that satellite‐based remote sensing, when used jointly with in situ ground‐truthing and machine learning algorithms, provides a powerful tool to predict the cover and richness of intertidal macroalgae. The salient finding was that the Sentinel‐based remote sensing described a significant proportion of variability in the cover and richness of Antarctic macroalgae. The highest performing models were for macroalgal richness and the cover of green algae as opposed to the model of brown and red algal cover. When expanding the geographical range of the ground‐truthing, even involving only a few sample points, it becomes possible to potentially map other Antarctic intertidal macroalgal habitats and monitor their dynamics. This is a significant milestone as logistical constraints are an integral part of the Antarctic expeditions. The method has also a potential in other remote coastal areas where extensive in situ mapping is not feasible.     

Macroinvertebrates as bioindicators of water quality in the Mkondoa River,Tanzania, in an agricultural area

The suitability of using macroinvertebrates as bioindicators of stream water quality was tested in the Mkondoa River in an agricultural area at Kilosa, using the rapid bioassessment protocol. The family biotic index (FBI) showed marked variation in water quality along the stream from values ranging from 4.1 to 5.0 in the upstream reaches, indicating good water quality, 5.3 to 5.5 in the mid-reaches and 6.0 to 6.5 in the lower reaches. The water quality index (WQI) indicated that water quality was fair (77 ± 0.98) in the upstream reach of the Mkondoa, marginal (55 ± 0.86) in the midstream reach and poor (33 ± 0.45) in the downstream reach. There were significant relationships between biological oxygen demand and dissolved oxygen and the occurrence of specific taxa, mainly Chironomus and Caenis. Significant changes in macroinvertebrate abundance were mostly related to changes in water quality. As in other parts of the world, macroinvertebrate communities proved to be good biological indicators of water quality and they should be used as bioindicators in long-term monitoring of this river.