Large-scale assessments of river health using an Index of Biotic Integrity with low-diversity fish communities

1. Effective tools are needed to measure the ‘health’ of rivers at scales large enough to be useful for management. Indicators for assessing the complex of variables that constitutes river health need to be ecologically based, efficient, rapid and consistently applicable in different ecological regions. 2. A large-scale survey of rivers in New South Wales, Australia provided data to test the Index of Biotic Integrity (IBI). The IBI employs the fish-community attributes, identified using regional and river-size data, expected for a river reach of excellent environmental quality. It uses metrics based on species richness, abundance, community structure and the health of individual fish. IBI metrics were established to suit a relatively low-diversity and unspecialized freshwater fish fauna in south-eastern Australia, totalling 55 species. 3. The IBI was able to discriminate between relative levels of environmental quality within a diverse set of stream systems and four presumptive ecological regions. The index was validated by testing the repeatability of scores, and by comparison of IBI scores at eighty sites with an independent measure of potential catchment condition, the River Disturbance Index. 4. Assessments of metric performance showed that eleven of the twelve metrics contributed satisfactorily. One metric based on trophic guild performed poorly and should be deleted from the index. Six other recommendations are made to enhance the performance of the IBI. 5. Results show that, while all large rivers have been disturbed, rivers in the Murray region and those in many coastal montane areas are particularly degraded. 6. The IBI results presented here demonstrate a validated method for large-scale monitoring of river health based on a fish fauna of limited diversity, in the absence of suitable reference sites.     

THE LIMNOLOGY OF SOME SOUTH AFRICAN IMPOUNDMENTS I. THE PHYSICO-CHEMICAL LIMNOLOGY OF HARTBEESPOORT DAM

SUMMARY

Hartbeespoort Dam is a eutrophic, warm monomictic lake with overturn occurring in April. The lake is stratified for about six months of the year and in late summer the stratification appears stable. Light penetration in the dam depends both on the inflow of turbid water as well as on the magnitude of the algal population. In summer the surface waters are often super-saturated with oxygen, whilst the hype limnion is anaerobic. The concentrations of nitrogen compounds, phosphate, Na, K, Ca, CI and SO₄ are higher in waters entering the dam via the Crocodile River. Nitrogen compounds arc the primary growth-limiting nutrients for algal growth and phosphate is the secondary growth-limiting nutrient. Phosphate concentrations in the water have increased approximately a hundredfold since 1928 and NO₃ ?N concentrations about threefold. The pH as well as the mineral content of the dam have also increased over the last 50 years.     

Relations quantitatives entre les populations de bryophytes aquatiques et la pollution des eaux courantes. Définition d'un indice de qualité des eaux

Résumé L'étude physico-chimique des eaux, couplée à celle de la répartition quantitative des espèces bryophytiques aquatiques et subaquatiques de la Sambre, de la Somme et de la Meuse (Belgique et Nord de la France), permet de tirer quelques conclusions quant à la résistance de ces espèces aux différents types de pollutions.La synthèse multivariable des résultats aboutit à l'élaboration d'un indice de qualité des eaux, qui est comparé avec l'indice similaire de Descy, relatif aux diatomées benthiques.

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The physico-chemical analysis of the waters, in conjunction with the quantitative distribution of the aquatic and subaquatic bryophytes in the rivers Sambre, Somme and Meuse (Belgium and North France), has led to conclusions about species resistance to different kinds of pollution.The data's multivariable synthesis gives a quality index of water and permits comparison with Descy's index for benthic diatoms.

Recherches bénéficiant de l'appui du Fonds de la Recherche Fondamentale Collective: programme du Centre de recherches fondamentales sur les bioindicateurs de la pollution des milieux continentaux.     

Developing a wetland IBI with statewide application after multiple testing iterations

An index of biotic integrity (IBI) is a frequently used approach for assessing the ecological integrity of streams with fish and macroinvertebrates the faunal assemblages most commonly used as indicator taxa. The IBI approach has been much less commonly applied to wetlands, despite the legal, policy and scientific need to assess wetland condition and develop ecological performance goals for wetland creation, restoration and enhancement. While some IBIs are sophisticated systems with statewide application that have undergone one or more testing iterations, many published IBIs are derived from single data sets of a single class of aquatic resource with limited geographic application. The State of Ohio initiated development of a wetland IBI using vascular plants in 1996. Sampling methods were investigated and ultimately a plot-based method was adopted. Potential attributes and different human disturbance gradients were evaluated in several studies. Ultimately, IBIs for emergent, forest and shrub dominated wetlands were developed. Data from the Vegetation IBI-emergent (VIBI-E) is presented to illustrate this process. Subsequent testing and refinement is a critical step in the development of a robust IBI with more than local application. Throughout its initial development (R² = 0.863, p < 0.001), first major testing iteration (R² = 82.2%, p < 0.001), second test iteration (R² = 75.0%, p < 0.001) and third test iteration (R² = 82.1%, p < 0.001), the VIBI-E has remained significantly correlated with the disturbance gradient. Eight of the original 10 metrics proposed continued to have significant and interpretable relationships with the disturbance gradient, with 4 metrics remaining completely unchanged, and 4 undergoing relatively minor modifications, and 2 being replaced. The VIBI-E and its component metrics were also evaluated against a new disturbance gradient (Landscape Development Index or LDI), derived from land use percentages within a 1 km radius of the wetlands, that was not used during VIBI-E development. The VIBI-E score and 9 of 10 metrics were significantly correlated with the LDI disturbance gradient providing separate confirmation of the VIBI. The Vegetation IBI-E consistently and reliably assessed wetland condition across the whole range of wetland types throughout Ohio's ecological regions.     

Relationships between mesohabitats, ichthyological communities and IBI metrics adapted to a European river basin (The Meuse, Belgium)

We investigated the influence of mesohabitats on fish communities and on attributes of a multimetric index of fish integrity in the River Meuse basin. Three consecutive 150 m sectors in a Meuse tributary (Ourthe, Belgium), each divided in two or three sub-sections presenting various percentages of mesohabitats (riffles, runs and pools), were sampled by electrofishing. In each sub-section, relative and absolute biomasses of each fish species were estimated. The presence of limnophilic cyprinids was inversely correlated (r ² = 0.70 and 0.56 for absolute and relative biomass, respectively) with the percentage of riffles. Salmonids preferred runs and their absolute biomass was highly dependent (r ² = 0.71) on the proportion of this mesohabitat, whereas biomass of limnophilic cyprinids was highly correlated (r ² = 0.75 and r ² = 0.82 for absolute and relative biomass, respectively) with pools. A positive correlation (r ² = 0.58) was established between relative biomass of predators and the percentage of this mesohabitat. An IBI was calculated for the three sectors on the basis of results from the entire Meuse catchment. Scores of most metrics showed low variation among sectors but values of two metrics (% of individuals as tolerant, % of individuals as ubiquitous spawners) were greatest in sector 2, where pools predominated. Further, the lowest IBI score (51/65, integrity class: fair to good) was recorded in sector 2 where pools dominated, while sector 1 (where runs dominated) obtained the highest score (63/65, integrity class: excellent). Sector 3 which has a balanced proportion of riffles and runs obtained an intermediate score (57/65). Considering the response of IBI to the natural variation of mesohabitat proportions, it appears that an accurate sampling requires the prospection of a variety of mesohabitats (with a majority of runs) for the evaluation of river quality.     

A fish-based multimetric index for Brazilian savanna streams

Multimetric indices (MMI) have been widely used to assess ecosystem conditions because they are low-cost, employ a rapid field method, and can incorporate various biological metrics at different levels of biological organization. Our objective was to create a fish-based multimetric index applicable to all streams of the Brazilian savanna biome (Cerrado), the second largest biome in Brazil and deemed a global biodiversity hotspot. We evaluated 156 sites in two river basins (Paraná and São Francisco) and selected metrics capable of distinguishing stream-sites across a gradient of anthropogenic disturbances. We employed two different MMI approaches to determine if an MMI based on natural variation-adjusted metrics performed better than one based on unadjusted metrics. In addition, we assessed the performance of the two final MMIs and their sensitivity to anthropogenic pressures at local (LDI), catchment (CDI) and both scales integrated (IDI). Finally, we employed the power of a probability sample survey design to infer headwater stream conditions across a hydrologic region of approximately 47,000 km². Our final MMI for Brazilian savanna streams included six metrics: % common species; % characiform individuals; % loricariid individuals; % trichomycterid individuals; % invertivore species, and % Poecilia reticulata individuals. MMI₁ (unadjusted metrics) performed better than MMI₂ (natural variation-adjusted metrics) in discriminating least- and most-disturbed sites, but MMI₂ distinguished intermediate from most-disturbed sites better than MMI₁. Both indices were negatively correlated with the CDI scores; however, only MMI₂ was negatively correlated with the IDI scores. We inferred that 709 km (9.35%) of streams in the studied hydrologic region were in good condition, 8115 km (82.73%) were intermediate, and 641 km (7.91%) were in poor condition. We conclude that the MMIs proposed in this study have great potential for widespread application because they integrate data from two of the most important Brazilian river basins included in a biome that represents more than 20% of the country. Furthermore, the metrics retained in the indexes are easy to access with a rapid low-cost field method. However, their feasibility in areas influenced by mining, as well as in different biomes, should be tested.     

广西河池地区河流基于鱼类的生物完整性指数筛选及其环境质量评估

为促进生物完整性评价法在中国的应用,加强珠江上游广西河池地区河流环境质量监测,该研究以鱼类为研究对象,初步构建了包含21个指标在内的广西河池地区河流基于鱼类的生物完整性评价的指标体系。根据鱼类调查所收集数据,结合历史资料的记录,对这些指标进行筛选和赋值,最终确立了6个指标,用于建立适合广西河池地区河流的基于鱼类的生物完整性指标体系;应用此指标体系对该地区部分河流(河段)进行了评价。评价的结果表明,小环江鱼类完整性为好;红水河、龙江和大环江为一般;刁江为极差。评价的结果与河流受人为干扰的实际情况相吻合,研究构建的评价体系可供河池周边地区使用和借鉴。生物完整性评价是水域环境质量监测的重要手段,为使生物完整性评价更加科学和客观,应加强生物完整性与环境因子之间关系的研究。     

Developing biological indicators from diverse data: The Potomac Basin-wide Index of Benthic Integrity (B-IBI)

A Basin-wide Index of Benthic Integrity (B-IBI) was developed to uniformly assess aquatic ecosystem health of non-tidal, wadeable streams in the multi-jurisdictional Potomac River basin (US). Multiple datasets were merged and used to identify stream classes and discriminating biological metrics. The index (aggregated metric scores) accurately identified 95% of impaired sites. A jackknife cross-validation procedure confirmed the accuracy of the B-IBI. B-IBI assessments generally compare favorably to basin states’ assessments derived from the same data. A habitat quality matrix which includes an indicator of anthropogenic alterations and disturbances is recommended. The Potomac B-IBI is more useful than existing state-specific indexes for stream health comparisons across jurisdictional boundaries and basin-wide. The Potomac B-IBI can improve understanding of water quality issues in the basin and enhance the abilities of water quality managers to make well-informed decisions concerning the basin's non-tidal waters.     

Status assessment in acid-sensitive and non-acid-sensitive Maryland coastal planin streams using an integrated biological,chemical, physical,and land-use approach

This study was designed to: (1) evaluate the ecological status of acid-sensitive and non acid-sensitive Maryland coastal plain streams using biological (Index of biotic Integrity [IBI] for fish), chemical and physical habitat conditions; (2) determine if a low IBI for coastal plain stream fish can be related to stream sensitivity from acidic inputs and (3) correlate land use activities and watershed size in the coastal plain streams with biological, chemical and physical conditions. IBI values obtained using 12 community metrics for Maryland coastal plain stream fish demonstrated that there were no significant differences in these values when acid-sensitive and non-acid-sensitive streams were compared. However, other complementary data in acid-sensitive streams such as absence of the acid-sensitive species, blacknose dace and higher numbers and biomass of tolerant species suggested that these streams may be impacted. IBI values were also found to be negatively correlated with various trace metals in acid-sensitive streams but not in non-acid-sensitive areas. Chemical conditions such as trace metals and nutrients were associated with land use activities. Highest concentrations of trace metals (chromium, nickel, and cadmium) were found in streams with the highest percentage of low residential housing. Nitrate concentrations were significantly higher in streams found in agricultural areas than in forested areas. Agriculturally dominated streams with highest nitrate concentrations (> 10 mg l^-1) also contained the highest percentage of livestock feeding operations. The mean IBI score for streams draining agricultural land was higher than the mean value for forested streams when all streams were compared. However, when several streams that were only marginally forested (< 50%) were removed from the analysis, the IBI scores did not differ significantly by land use. Two physical habitat indices exhibited a strong associated with each other. Each habitat index also correlated with IBI values.     

Measuring the responses of macroinvertebrate communities to water pollution: a comparison of multivariate approaches, biotic and diversity indices

The responses of macroinvertebrate communities to pollution by sewage effluent in the River Trent system (UK) were investigated using a variety of multivariate approaches, biotic indices and diversity indices. It was found that multivariate analyses clearly illuminated the change of community structure along the pollution gradient. CY Dissimilarity Measure (CYD)-based Non-Metric Multidimensional Scaling (NMDS) appeared to perform better than DCA and clustering. Species richness, the BMWP, BMWP-ASPT, the Chandler Score, Chandler-ASPT could detect the effects of major pollution. However, these indices showed varying sensitivity to different ranges of pollution, for example, Chandler-ASPT and BMWP-ASPT are more sensitive to the change in clean/slightly polluted range than in the moderate/very polluted range. The diversity indices were the least informative. The advantages and disadvantages of the various approaches were discussed.     

An advanced Index of Biotic Integrity for use in tropical shallow lowland streams in Costa Rica: Fish assemblages as indicators of stream ecosystem health

This paper presents an advanced version of the Index of Biotic Integrity (IBI), a multimetric index to indicate ecosystem health. The multimetric index has been adapted in such a way that it not only indicates overall condition but also specific causes of environmental disturbance. The newly developed index (a) uses data of tolerant as well as intolerant species in a single metric to indicate environmental disturbance, (b) does not require knowledge about species from the literature, and (c) can be applied to artificial landscapes.The metrics proposed here consist of indicator species assemblages that are selected directly for their relationship with an environmental component or specific type of environmental degradation. Thus, each metric indicates a type of environmental concern, which enables conservation practices to be targeted more effectively. Species assemblages for each single metric consist of a combination of species that can be negatively and positively related to environmental disturbances, providing a better indication of stream ecosystem health.The area studied was assumed to be too diverse for one single index. Canonical Indirect-Gradient Principal Component Analysis indicated that the optimal division of subindices based on stream typology was for streams with drainage basin sizes <10 km² and >10 km². Pearson Product-Moment Correlations were used to identify relationships between anthropogenic disturbances and the composition and abundance of fish species at impacted as well as undisturbed sites. This index proved to be useful for indicating overall stream ecosystem health as well as local onsite environmental disturbances or the environmental components of greatest concern. This index does require extensive information about measured levels of anthropogenic disturbances with the accompanying composition and abundance of fish species.     

青藏高原跳甲亚科昆虫区系研究

讨论青藏高原（包括横断山区）的跳甲亚科昆虫区系。该区已知47属228种。1）据属级阶元的分布类型分析,以东洋属和南型属种显占优势,是区系主体,显示该区跳甲区系的热带渊源,其中高山属种赋予该区以高山区系特征;2）该区物种分化活跃,是某些多种属中国种类的分布中心和分化中心;3）联系中国跳甲亚科区系,在地理分布格局上显示西－东分布,如Hespera属的分布和西南－东北分布或西南－东北的间断分布格局,如Pentamesa和Stenoluperus属的分布。这种地理分布格局反映青藏高原的隆起给中国昆虫区系带来重要影响。     

Modification of an index of biotic integrity based on fish assemblages to characterize rivers of the Seine Basin,France

The Index of Biotic Integrity (IBI) is a measure of fish assemblage health that has been used to assess catchment and stream quality throughout North America. It reflects human perturbations on natural environmental structures and processes. While preserving the ecological foundation of the original North American metrics, we have modified and adapted the IBI to the mainstem Seine River and its major tributaries in France. This successful modification of the IBI to a considerably different fish fauna on a different continent further supports its wider use outside the midwestern United States. Using data collected in 1967, 1981, and 1988–1989 from a total of 46 sites, we show spatial and temporal variation in the Seine as indicated by IBI scores. Statistically significant relationships were found between IBI and catchment area but insignificant relationships existed between IBI and an independent Water Quality Index (WQI) based on water chemistry. Comparisons between the IBI and the WQI indicate that the former is a more sensitive and robust measure of water body quality. Our results demonstrate that the IBI, combined with a statistically designed national monitoring program, would offer a reliable means of assessing spatial patterns and temporal trends in water body improvement or degradation in France. The more primitive fish families in the Basin were affected first by perturbations. These families include all the diadromous species found in the Seine and suggest serious disruption of their life histories.     

Assessing the suitability of five benthic indices for environmental health assessment in a large subtropical South American estuary

Despite the increased and widespread usage of benthic indices for environmental health assessment, some methodological ambiguities remain to be solved. We tested the congruence and consistency of the benthic indices ITI, BO2A, BENTIX, AMBI and M-AMBI in a subtropical estuary (Paranaguá Bay, Brazil). Indices were applied to non-vegetated tidal flats increasingly contaminated by sewage to test: (i) correlations with molecular biomarkers of sewage (consistency); and (ii) evaluate the overall agreement/similarity of responses (congruence). The responses of the benthic indexes ITI, AMBI and BO2A were congruent among themselves and consistent with molecular biomarkers values. BENTIX and M-AMBI were less consistent and congruent and possibly need a readjustment of boundaries for subtropical habitats. The indices seemed robust to natural background yearly variations not related to contamination. Faecal sterols associated to nutrient contents suitably supported the validation of indices and could integrate reference conditions for sewage impacted coastal habitats. Benthic indices can successfully integrate management guidelines, but their suitable application demands further research on tolerance shifts of key indicator species.     

新世纪中推动生物科学发展的“Bio-X”

近二年国际上正掀起建立以生物科学为中心的交叉学科研究中心或研究所等实体的热潮。其中最引入注目的是美国斯坦福大学以诺贝尔物理学奖获得者朱棣文教授等人组建的“Bio-X”研究中心。Bio-X中的Bio为生物学,X泛指物理学、化学、工程学、医学等其它学科,在新世纪到来之时,生物科学中有不少迅速发展的领域迫切需要多学科交叉共同研究和参与,特别是：后基因组、基于同步辐射的结构生物学、单分子测量、纳米技术、脑科学、生物医学工程等。     

The development of a Biotic Pollution Index for the River Nile in Egypt

This article describes the development of a Nile Biotic Pollution Index (NBPI) for the River Nile in Egypt. Chemical data were collected from 30 locations along the Nile from Aswan to Cairo and 21 sites within the river delta, incorporating a range of conditions from unpolluted to grossly polluted. Seven chemical variables were used to calculate a Nile Chemical Pollution Index (NCPI) for each site. Biological data were collected primarily using Artificial Substrate Samplers (ASS). The UK developed, Biological Monitoring Working Party (BMWP) biotic index and the BMWP-ASPT were applied to the data. A Nile Biotic Pollution Index (NBPI) and the NBPI-ASPT were obtained by incorporating more of the Nile taxa. There were highly significant regressions (P < 0.001) for both the UK and the Nile Pollution Index scores with the NCPI for the whole river. The modification of the UK indices improved the Nile Indices increasing the number of taxa recorded from 29 to 43 and the total number of recorded taxon occurrences from 377 to 490. The Nile Indices provided better discrimination at both ends of the pollution spectrum. The NBPI-ASPT was best for the river as a whole, and particularly for the river from Aswan to Cairo. The NBPI was much better in the delta than from Aswan to Cairo. These differences in performance were attributed to the fact that the NBPI-ASPT excludes information on taxon diversity. In clean waters there was a wide range of NBPI score suggesting that the biodiversity of taxa is dependent on other aspects of habitat quality. Conversely in the polluted delta the high score of an individual taxon is critical for the NBPI-ASPT as it may have a distorting effect. As the NBPI-ASPT was the most consistent biotic index it is recommended as the regular biological assessment and regulatory tool for Egypt to meet the requirements of the Convention for Biodiversity. Handling editor: R. Norris     

新疆金龟甲的区系组成及食性(鞘翅目：金龟甲总科)

初步查明,新疆金龟甲昆虫计有154种,分隶于2科、13亚科、47属**。区系组成含中亚细亚、中央亚细亚、欧洲—西伯利亚、地中海、特有种、泛古北种和全北种等多种成分,其中以中亚细亚种类最多,达74种,约占48.5%。结合区系组成的分析,提出了新疆昆虫地理区划的划分意见。新疆金龟甲成虫的食性可分为粪食型、腐食型、角质物食型、尸食型、植食型和绝食型,其中粪食型达75种,约占49%,具有重要生态意义;植食型55种,约占36%,具有重要经济意义。     

四川壤塘县绰斯甲河段鸟类资源初步调查及区系分析

四川壤塘县处于中国古北界与东洋界的过渡地带,因此研究其鸟类区系具有一定意义。2010年8月和12月对壤塘县绰斯甲河段鸟类资源及区系进行了初步调查。结果表明,该区共有鸟类152种,包括留鸟102种,夏候鸟38种,冬候鸟5种,旅鸟7种。其中,中国特有鸟类12种,国家Ⅰ、Ⅱ级重点保护鸟类和省级重点保护鸟类20种。     

Benthic, Drifting and Marginal Macroinvertebrate Assemblages in a Lowland River: Temporal and Spatial Variations and Size Structure

Aquatic macroinvertebrates living in anastomosing lowland rivers use different habitats and respond differently to the hydrological regime. In this paper, the structure and composition of benthic, drifting and marginal macroinvertebrate assemblages are analyzed in the lowland river Ctalamochita (Córdoba, Argentina). The assemblages were studied in an annual cycle; a comparison among the composition of benthos, drift and marginal fauna was carried out; and size structure of the assemblages was characterized. Samples were obtained from two sites: a rural and an urban site. In total 73 taxa of aquatic macroinvertebrates were collected. Benthos was characterized by Chironomidae and Oligochaeta; marginal fauna was mainly constituted by Coleoptera, Heteroptera, Decapoda, the Trichoptera Nectopsyche sp., Ephemeroptera and Odonata. Drifting assemblage was composed by macroinvertebrates from local and remote upstream benthos, and from the marginal zone. Marginal fauna diversity was higher than benthos and drift. Total biomass of the assemblages pooled together was relatively equitably among size classes. Larger size classes consisted of organisms from the marginal zone whereas the smallest ones were composed by benthic and drifting organisms. In the study area there is habitat partitioning in the lateral dimension of the river. Marginal fauna was more diverse due to the asymmetry of transport and deposit processes, which generate a heterogeneous habitat in the bankside. The relation between fine substrate and high current velocity determines an unstable habitat in the central channel, which makes colonization by benthic macroinvertebrates difficult.