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Sample records for benthic macroinvertebrate assemblages

  1. Linkages between benthic macroinvertebrate assemblages and landscape stressors in the US Great Lakes

    Science.gov (United States)

    We used multiple linear regression analysis to investigate relationships between benthic macroinvertebrate assemblages in the nearshore region of the Laurentian Great Lakes and landscape characteristics in adjacent watersheds. Benthic invertebrate data were obtained from the 201...

  2. Benthic macroinvertebrate assemblages in the US nearshore zone of Lake Erie, 2009: Status and linkages to landscape-derived stressors

    Science.gov (United States)

    Benthic macroinvertebrate assemblages have been used as indicators of ecological condition because their responses integrate localized environmental conditions of the sediments and overlying water. Assemblages of benthic invertebrates in the near coastal region are of particular...

  3. Effects of anthropogenic impacts on benthic macroinvertebrates assemblages in subtropical mountain streams

    Directory of Open Access Journals (Sweden)

    Leticia M. Mesa

    2013-12-01

    Full Text Available The nature of the riparian and surrounding landscape has been modified by anthropogenic activities, which may subsequently alter the composition and functional structure of macroinvertebrate assemblages. The effect of these changes on function of benthic fauna is difficult to assess due to the scarce knowledge on functional structures in tropical streams. In this study we evaluate whether sites impacted and unimpacted by anthropogenic alterations differed in assemblage composition and density, richness and diversity of each functional feeding group. The selection of the sites was related to their distinct riparian characteristics, following the QBRy riparian quality index. Collector-gatherer was the dominant functional feeding group, comprising 91% of total density, whereas the proportion of shredders was very low, representing less of 0.5% of total density. Asemblage composition of macroinvertebrates differed between impacted and unimpacted sites. Predators were dominant in taxa number, representing about 60% of total taxa richness. In addition, the diversity and richness of collector-gatherers differed significantly between degraded and unimpacted sites, reflecting the sensitivity of this group to environmental changes and the utility to be used in the assessment of anthropogenic modifications. The results of this study reinforce the idea that riparian corridor management is critical for the distribution of macroinvertebrate assemblages as well as functional organization of lotic streams.

  4. Comparison of ecological diversity and species composition of macroalgae, benthic macroinvertebrates, and fish assemblages between two tropical rocky reefs

    OpenAIRE

    Verónica C. García-Hernández; Héctor Reyes-Bonilla; Balart, Eduardo F; Eduardo Ríos-Jara; Lluch-Cota, Salvador E.; Elisa Serviere-Zaragoza

    2014-01-01

    Within the marine environment, the rocky shores are recognized for their high species diversity and particularly transitional zones represent areas of biotic mix, promoted by historical and ecological natural variations that allow the presence of taxa from different regions and which present dissimilar biological traits. An extensive survey describes the benthic macroalgae, macroinvertebrates (molluscs, crustaceans, and echinoderms), and fish assemblages at two rocky reefs, Islas Marietas and...

  5. Temporal variability in discharge and benthic macroinvertebrate assemblages in a tropical glacier-fed stream

    DEFF Research Database (Denmark)

    Jacobsen, Dean; Andino, Patricio; Calvez, Roger;

    2014-01-01

    Abstract High flows are major disturbances in streams and cause benthic communities to vary temporally. Meltwater runoff in glacier-fed streams at temperate–arctic latitudes primarily follows a strong seasonal pattern. In contrast, such streams at the equator show less seasonal, but more......-pronounced diel variability in discharge that tracks a year-round diurnal melting–nocturnal freezing cycle of glaciers. Consequently, qualitative and quantitative differences in temporal variability of macrobenthos communities should be expected between high-latitude and tropical glacier-fed streams. We explored...... temporal variability in density, taxon richness, and community composition of benthic macroinvertebrates and analyzed community responses to flow events at 3 sites along a glacier-fed stream in equatorial Ecuador (0.05, 1.6, and 4.3 km from the glacier front). We obtained continuous flow recordings...

  6. Benthic macroinvertebrate assemblages and sediment toxicity testing in the Ely Creek watershed restoration project

    International Nuclear Information System (INIS)

    The Ely Creek watershed in Lee County, Virginia, contains an abundance of abandoned mined land (AML) seeps that contaminate the majority of the creek and its confluence into Big Stone Creek. Contaminated sediments had high concentrations of iron (∼10,000 mg/kg), aluminum (∼1,500 mg/kg), magnesium (∼400 mg/kg) and manganese (∼150 mg/kg). Copper and zinc generally ranged from 3 to 20 mg/kg. Benthic macroinvertebrates surveys at six of 20 sites sampled in the watershed yielded no macroinvertebrates, while eight others had total abundances of 1 to 9 organisms. Four reference sites contained ≥100 organisms and at least 14 different taxa. Laboratory, 10-day survival/impairment sediments tests with Daphnia magna did not support the field data. Mortality of 92 to 100% for D. magna occurred in samples collected from six cities. Daphnid reproduction was more sensitive than laboratory test organism survivorship; however, neither daphnid survivorship nor reproduction were good predictors of taxa richness. Laboratory test concerns included the use of a reference diluent water rather than site specific diluent water

  7. Nationwide Benthic Macroinvertebrate Assemblage Multimetric Indices: Identifying Inconsistencies and Limitations in Reporting Stream Impairment Status, USA

    Science.gov (United States)

    Lau, J. K.; Lauer, T. E.

    2015-07-01

    The objective of this study was to identify the current status of stream water-quality assessment and reporting methods for four states in the Ohio River basin (Indiana, Ohio, Tennessee, and Virginia), as required by the 305(b) section of the United States (US) Clean Water Act. Specifically, we clarified the discrepancies that exist among stream-impairment status classified by benthic macroinvertebrate multimetric indices (MMIs) and depicted using Geographic Information Systems shapefiles. In addition, we provided guidance in solving some of the comparability problems that arise when developing state-specific MMIs and depicting stream-impairment status using Geographic Information Systems technology. The MMI variation among states and differences in shapefile formats resulted in a nationwide dataset, which cannot be directly compared. Incorporating the changes suggested in this study allow for a uniform assessment and reporting method nationwide. Successful implementation of these changes would strengthen the US Environmental Protection Agency efforts to identify impaired streams and sources of those impairments without the limitations of state-by-state .developed assessment methods.

  8. Evaluation of benthic macroinvertebrate assemblage for disturbance zonation in urban rivers using multivariate analysis: Implications for river management

    Science.gov (United States)

    Shah, Ram Devi Tachamo; Shah, Deep Narayan

    2013-08-01

    River pollution has tremendously increased in the major cities of South Asia, where the rivers have become a repository for domestic, agricultural, municipal and industrial wastes. This study presents the evaluation of benthic macroinvertebrate assemblage as a means of assessing ecological status, determining different disturbance zones and identifying environmental variables and stressors that deteriorate the river ecosystem. In total, 20 sites in 36-km stretch of the main stem of the Bagmati River and 7 sites on its tributaries were selected for sampling in the post-monsoon and pre-monsoon seasons during the time period 2008-2010. The Ganga River System Biotic Score (GRSbios) index was applied to determine the ecological status. The ecological status of the different Bagmati River stretches ranged from reference (Class 1) to extremely polluted (Class 5). We identified three types of disturbance zones along the river, ranging from minimally polluted to extremely polluted. A river corridor survey was conducted to identify any river stressing factors, revealing a sharp deterioration of the river from upstream to downstream with increasing concentrations of chloride and ortho-phosphate phosphorus. Effluents and Activities and Facilities were found to be the major stressing factors to the river ecosystem. The information gained should help water managers find the most time-efficient and cost-effective measures to address river degradation.

  9. Evaluation of benthic macroinvertebrate assemblage for disturbance zonation in urban rivers using multivariate analysis: Implications for river management

    Indian Academy of Sciences (India)

    Ram Devi Tachamo Shah; Deep Narayan Shah

    2013-08-01

    River pollution has tremendously increased in the major cities of South Asia, where the rivers have become a repository for domestic, agricultural, municipal and industrial wastes. This study presents the evaluation of benthic macroinvertebrate assemblage as a means of assessing ecological status, determining different disturbance zones and identifying environmental variables and stressors that deteriorate the river ecosystem. In total, 20 sites in 36-km stretch of the main stem of the Bagmati River and 7 sites on its tributaries were selected for sampling in the post-monsoon and pre-monsoon seasons during the time period 2008–2010. The Ganga River System Biotic Score (GRSbios) index was applied to determine the ecological status. The ecological status of the different Bagmati River stretches ranged from reference, class 1 to class 5 (extremely polluted). We identified three types of disturbance zones along the river, ranging from minimally polluted to extremely polluted. A river corridor survey was conducted to identify any river stressing factors, revealing a sharp deterioration of the river from upstream to downstream with increasing concentrations of chloride and ortho-phosphate phosphorus. Effluents and Activities and Facilities were found to be the major stressing factors to the river ecosystem. The information gained should help water managers find the most time-efficient and cost-effective measures to address river degradation.

  10. Abiotic stream types and species assemblages: is there any simle linkage? Czech streams and benthic macroinvertebrates as an example

    Czech Academy of Sciences Publication Activity Database

    Zahrádková, S.; Brabec, K.; Kokeš, J.; Němejcová, D.; Soldán, Tomáš; Jarkovský, J.; Pařil, P.; Hájek, O.

    2005-01-01

    Roč. 29, - (2005), s. 1087-1094 R&D Projects: GA AV ČR(CZ) 1QS500070505 Institutional research plan: CEZ:AV0Z50070508 Keywords : typology * biocenoses * benthic macroinvertebrates Subject RIV: EH - Ecology, Behaviour

  11. Effects of Urbanization on the Condition of Streams in the Piedmont of North Carolina: Responses of Benthic Macroinvertebrate Assemblages

    Science.gov (United States)

    Cuffney, T. F.; Harned, D. A.; McMahon, G.; Giddings, E. M.

    2004-12-01

    The effects of urbanization on the physical, chemical, and biological characteristics of streams in the North Carolina Piedmont were investigated as part of the U.S. Geological Survey's National Water-Quality Assessment (NAWQA) Program. Over 1,200 candidate basins (2-3rd order streams) were identified using a 30-m digital elevation model. A multimetric urban intensity index (UII) derived from population, infrastructure, land use, land cover, and socioeconomic factors was used to characterize the degree of urbanization in each basin. Candidate basins were grouped together based on natural features (e.g., ecoregion, elevation, relief, and soil characteristics) and a subset of 30 basins was selected for study on the basis of uniformity in natural features, representation of the urban gradient (i.e., low to high UII), and accessibility. Biological (fish, benthic macroinvertebrates, and algae), physical (stream stage, temperature, and habitat), and chemical (nutrients, pesticides, and major ions) characteristics were measured in each stream and related to changes in the UII. Biological responses were assessed using multivariate (i.e., assemblage ordinations) and multimetric (i.e., assemblage metrics) methods. The relations between invertebrate responses, the UII, and characteristics of urbanization are described in this paper. These relations were examined using correlations and regressions. Invertebrate assemblages exhibited strong responses to the UII based on ordination site scores (Y = -0.013X + 1.613, R2 = 0.78, P urbanization. Response rates in the North Carolina Piedmont were similar to response rates reported for the Boston, MA (ordination -0.016, EPT richness -0.268, tolerance 0.015), Birmingham, AL (ordination -0.017, EPT richness -0.168, tolerance 0.015), and Salt Lake City, UT (ordination -0.012, EPT richness -0.169, tolerance 0.021) metropolitan areas based on previous NAWQA Program urban gradient studies. The characteristics of urbanization most strongly

  12. The assemblage characteristics of benthic macroinvertebrates in the Yalutsangpo River, the highest major river in the world

    Science.gov (United States)

    Xu, Mengzhen; Wang, Zhaoyin; Pan, Baozhu; Yu, Guoan

    2014-09-01

    Aquatic ecosystems of highland rivers are different from those of low altitude rivers because of the specific topography and environmental parameters associated with high altitudes. Yalutsangpo, the upper course of the Brahmaputra River, is the highest major river in the world, flowing from west to east across Tibet, China and pouring into India. Macroinvertebrates were sampled from Yalutsangpo and its tributaries, the Lhasa, Niyang, and Parlong Tsangpo Rivers, from October 2009 to June 2010, to study characters of the highland aquatic ecosystem. Altogether, 110 macroinvertebrate taxa belonging to 57 families and 102 genera were identified from the basin. The biodiversity and composition of macroinvertebrate assemblages were strongly affected by altitude gradients. Local diversity represented by taxa richness and the improved Shannon-Wiener index were high at altitudes of 3,300-3,700 m, among which suitability of habitat was higher due to the better integrated environmental conditions of water temperature, dissolved oxygen, and aquatic vegetation, etc. Macroinvertebrates were grouped into shredders, scrapers, predators, collector-filterers, and collector-gatherers according to their feeding behaviors. It was found that the distributions of the functional feeding groups varied with habitat altitudes. Shredders were present at altitudes of 2,900-4,400 m, while scrapers mainly inhabited altitudes of 3,500-4,500 m, and collector-filterers preferred 3,500-4,000 m. Even though the local taxa richness was not high at each site, the taxonomic composition and density of the assemblages varied greatly among the different sites, resulting in much higher regional diversity compared to the lowland river with similar flow and substrate conditions. The regional cumulative taxa richness of Yalutsangpo decreased and more families were lost as the altitude increased. However, some families that were newly present as the altitude increased were essential for sustaining the high

  13. THE RESPONSE OF BENTHIC MACROINVERTEBRATE AND FISH ASSEMBLAGES TO HUMAN IMPACT ALONG THE LOWER STRETCH OF THE RIVERS MORAVA AND DYJE (DANUBE RIVER BASIN, CZECH REPUBLIC

    Directory of Open Access Journals (Sweden)

    Zdeněk Adámek

    2013-10-01

    Full Text Available The lower Morava and Dyje rivers belong among the large lowland rivers on the southeast of the Czech Republic flowing into the Danube 69 km downstream of their confluence. Despite their high nature value and environment protection, both rivers suffered from heavy pollution from the sixties to the eighties of the last century. Significant improvement of their water quality during the last two decades resulted in the partial recovery of former assemblages of both benthic macroinvertebrates and fish. Recently, altogether 262 and 137 taxa of macrozoobenthos were recorded at the Dyje and Morava rivers, respectively. In the River Dyje, 3 and 21 non-native and threatened (according to IUCN categories invertebrate species, respectively, were ascertained, whilst in the River Morava their numbers were 2 and 10, respectively. The fish assemblage consisted of 23 and 24 species, respectively, plus one hybrid in each of the rivers, bleak being by far the most abundant fish. In the sections under study, several rare and/or protected species were also recorded. Two of them, ide (Leuciscus idus and burbot (Lota lota belong among vulnerable fish species and four others, white-eye bream (Abramis sapa, striped ruffe (Gymnocephalus schraetser, streber (Zingel streber and zingel (Zingel zingel, are considered as critically endangered species. Currently, both lower stretches of the rivers Morava and Dyje have been heavily invaded by round goby, Neogobius melanostomus.

  14. Effects of urbanization on benthic macroinvertebrate assemblages in contrasting environmental settings: Boston, Massachusetts; Birmingham, Alabama; and Salt Lake City, Utah

    Science.gov (United States)

    Cuffney, T.F.; Zappia, H.; Giddings, E.M.P.; Coles, J.F.

    2005-01-01

    Responses of invertebrate assemblages along gradients of urban intensity were examined in three metropolitan areas with contrasting climates and topography (Boston, Massachusetts; Birmingham, Alabama; Salt Lake City, Utah). Urban gradients were defined using an urban intensity index (UII) derived from basin-scale population, infrastructure, land-use, land-cover, and socioeconomic characteristics. Responses based on assemblage metrics, indices of biotic integrity (B-IBI), and ordinations were readily detected in all three urban areas and many responses could be accurately predicted simply using regional UIIs. Responses to UII were linear and did not indicate any initial resistance to urbanization. Richness metrics were better indicators of urbanization than were density metrics. Metrics that were good indicators were specific to each study except for a richness-based tolerance metric (TOLr) and one B-IBI. Tolerances to urbanization were derived for 205 taxa. These tolerances differed among studies and with published tolerance values, but provided similar characterizations of site conditions. Basin-scale land-use changes were the most important variables for explaining invertebrate responses to urbanization. Some chemical and instream physical habitat variables were important in individual studies, but not among studies. Optimizing the study design to detect basin-scale effects may have reduced the ability to detect local-scale effects. ?? 2005 by the American Fisheries Society.

  15. Benthic Macroinvertebrate Communities in Agriculturally Impaired Streams

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    Virginija Pliuraite

    2009-10-01

    Full Text Available Normal 0 false false false EN-US X-NONE X-NONE This work presents research into the taxonomic composition of macroinvertebrate communities in streams that are under the influence of agricultural pollution A total of 67 macroinvertebrate taxa (including 61 identified species belonging to 40 families have been identified in the explored streams. The greatest species richness is recorded for the Trichoptera (18 species/1 taxa and Mollusca (12 species. The molluscs Gyraulus albus, amphipods Gammarus pulex, caddisflies Hydropsyche pellucidula and oligochaetes are detected in all examined streams. There, the number of total benthic macroinvertebrate taxa is highly variable, ranging from 16 to 40. Results show that the examined streams depending on the benthic macroinvertebrate taxonomic composition and predominance of seperate macroinvertebrate groups undergo different pollution. Intolerant to pollution taxa such as Plecoptera, which are the most sensitive to pollution insects, have been found only in 5 of 12 examined streams and in low abundances. The richness and diversity of macrozoobenthos in some streams appear to respond to the water quality deterioration. The present study has found out that in the stream where the total macroinvertebrate taxa, EPT taxa richness are the lowest and a relative abundance of gatherers is the highest, the values of NH4-N, NO3-N, total N, PO4-P and total P in the stream water are the highest, too.

  16. Land Use Influences Niche Size and the Assimilation of Resources by Benthic Macroinvertebrates in Tropical Headwater Streams

    OpenAIRE

    Parreira de Castro, Diego Marcel; Reis de Carvalho, Débora; Pompeu, Paulo dos Santos; Moreira, Marcelo Zacharias; Nardoto, Gabriela Bielefeld; Callisto, Marcos

    2016-01-01

    It is well recognized that assemblage structure of stream macroinvertebrates changes with alterations in catchment or local land use. Our objective was to understand how the trophic ecology of benthic macroinvertebrate assemblages responds to land use changes in tropical streams. We used the isotope methodology to assess how energy flow and trophic relations among macroinvertebrates were affected in environments affected by different land uses (natural cover, pasture, sugar cane plantation). ...

  17. Benthic macroinvertebrates in Italian rice fields

    Directory of Open Access Journals (Sweden)

    Daniela Lupi

    2013-02-01

    Full Text Available Rice fields can be considered man-managed temporary wetlands. Five rice fields handled with different management strategies, their adjacent channels, and a spring were analysed by their benthic macroinvertebrate community to i evaluate the role of rice agroe- cosystem in biodiversity conservation; ii find indicator species which can be used to compare the ecological status of natural wetlands with rice agroecosystems; and iii find the influence of environmental variables on biodiversity. Different methods of data analysis with increasing degree of complexity – from diversity index up to sophisticated multivariate analysis – were used. The investigation provided a picture of benthic macroinvertebrates inhabiting rice agroecosystems where 173 taxa were identified, 89 of which detected in rice paddies. Among them, 4 phyla (Mollusca, Annelida, Nematomorpha, and Arthropoda, 8 classes (Bivalvia, Gastropoda, Oligochaeta, Hirudinea, Gordioida, Insecta, Branchiopoda, and Malacostraca, 24 orders, 68 families, 127 genera and 159 species have been found. Ten threatened and 3 invasive species were detected in the habitats examined. The information obtained by the different methods of data analysis allowed a more comprehensive view on the value of the components of rice agroecosystems. Data analyses highlighted significant differences between habitats (feeding channel and rice field, with higher diversity observed in channels, and emphasised the role of the water chemical-physical parameters. The period of water permanence in rice fields resulted to be only one of the factors influencing the community of benthic macroinvertebrates. The presence of rare/endangered species allowed characterising some stations, but it was less informative about management strategies in rice paddies because most of these species were absent in rice fields.

  18. Evaluation of Environmental Factors to Determine the Distribution of Functional Feeding Groups of Benthic Macroinvertebrates Using an Artificial Neural Network

    NARCIS (Netherlands)

    Verdonschot, P.F.M.

    2008-01-01

    Functional feeding groups (FFGs) of benthic macroinvertebrates are guilds of invertebrate taxa that obtain food in similar ways, regardless of their taxonomic affinities. They can represent a heterogeneous assemblage of benthic fauna and may indicate disturbances of their habitats. The proportion of

  19. 城市溪流中径流式低坝对底栖动物群落结构的影响%The impact of run-of stream dams on benthic macroinvertebrate assemblages in urban streams

    Institute of Scientific and Technical Information of China (English)

    韩鸣花; 于海燕; 周斌; 张勇; 王备新

    2012-01-01

    Study of the degradation of urban stream ecosystems has been an important focus of urban ecology. During urbanization, infrastructure such as dams and other water projects can have a significant impact on the stream ecosystem. Dams create barriers, upstream and downstream, which hinder the migration of benthic invertebrates, change their living environment and affect their reproductive success, negatively affecting the macroinvertebrate community and its structure. This destroys the integrity of the stream ecosystem. To date, there has been no published research on this topic in China. Therefore, we surveyed the macroinvertebrate assemblages of nine sites (six in urban streams with run-of stream dams [ 2- 3m] and three in reference forest streams) in August, in Xitiao River catchment, Anji County, Zhejiang Province. Using the data collected, we explored the biological degradation of urban streams and the impact of run-of stream dams on the structure and composition of the macroinvertebrate community as well as on a range of biochemical parameters. Multiple comparison and non-parametric tests were used to compare the biochemical parameters of the different stream types, performed using SPSS 18.0 statistical software. Non-metric multidimensional scaling (NMDS) analysis was used to compare the community composition, performed using Primer 6.0 software. Our results showed that the main substrate components of the reference sites were boulders (35.92% ) and cobbles (33.66% ) , while the substrate of the urban streams was mostlygravel (57.97% ). Water temperature, conductivity, and concentrations of total nitrogen and total phosphorous were all significantly ( P < 0. 05) higher in urban streams than in reference streams, whereas total taxa richness and EPT ( Ephemeroptera, Plecoptera and Trichoplera) taxa richness were significantly (P<0.05) lower in the urban streams than in the reference streams. Differences in velocity (P=0.273) and depth/width (/* = 3.92) between

  20. Hydrologic controls on basin-scale distribution of benthic macroinvertebrates

    Science.gov (United States)

    Bertuzzo, E.; Ceola, S.; Singer, G. A.; Battin, T. J.; Montanari, A.; Rinaldo, A.

    2013-12-01

    The presentation deals with the role of streamflow variability on basin-scale distributions of benthic macroinvertebrates. Specifically, we present a probabilistic analysis of the impacts of the variability along the river network of relevant hydraulic variables on the density of benthic macroinvertebrate species. The relevance of this work is based on the implications of the predictability of macroinvertebrate patterns within a catchment on fluvial ecosystem health, being macroinvertebrates commonly used as sensitive indicators, and on the effects of anthropogenic activity. The analytical tools presented here outline a novel procedure of general nature aiming at a spatially-explicit quantitative assessment of how near-bed flow variability affects benthic macroinvertebrate abundance. Moving from the analytical characterization of the at-a-site probability distribution functions (pdfs) of streamflow and bottom shear stress, a spatial extension to a whole river network is performed aiming at the definition of spatial maps of streamflow and bottom shear stress. Then, bottom shear stress pdf, coupled with habitat suitability curves (e.g., empirical relations between species density and bottom shear stress) derived from field studies are used to produce maps of macroinvertebrate suitability to shear stress conditions. Thus, moving from measured hydrologic conditions, possible effects of river streamflow alterations on macroinvertebrate densities may be fairly assessed. We apply this framework to an Austrian river network, used as benchmark for the analysis, for which rainfall and streamflow time-series and river network hydraulic properties and macroinvertebrate density data are available. A comparison between observed vs "modeled" species' density in three locations along the examined river network is also presented. Although the proposed approach focuses on a single controlling factor, it shows important implications with water resources management and fluvial

  1. Effects of grade control structures on the macroinvertebrate assemblage of an agriculturally impacted stream

    Science.gov (United States)

    Litvan, M.E.; Stewart, T.W.; Pierce, C.L.; Larson, C.J.

    2008-01-01

    Nearly 400 rock rip-rap grade control structures (hereafter GCS) were recently placed in streams of western Iowa, USA to reduce streambank erosion and protect bridge infrastructure and farmland. In this region, streams are characterized by channelized reaches, highly incised banks and silt and sand substrates that normally support low macroinvertebrate abundance and diversity. Therefore, GCS composed of rip-rap provide the majority of coarse substrate habitat for benthic macroinvertebrates in these streams. We sampled 20 sites on Walnut Creek, Montgomery County, Iowa to quantify macroinvertebrate assemblage characteristics (1) on GCS rip-rap and at sites located (2) 5-50 m upstream of GCS, (3) 5-50 m downstream of GCS and (4) at least 1 km from any GCS (five sites each). Macroinvertebrate biomass, numerical densities and diversity were greatest at sites with coarse substrates, including GCS sites and one natural riffle site and relatively low at remaining sites with soft substrates. Densities of macroinvertebrates in the orders Ephemeroptera, Trichoptera, Diptera, Coleoptera and Acariformes were abundant on GCS rip-rap. Increases in macroinvertebrate biomass, density and diversity at GCS may improve local efficiency of breakdown of organic matter and nutrient and energy flow, and provide enhanced food resources for aquatic vertebrates. However, lack of positive macroinvertebrate responses immediately upstream and downstream of GCS suggest that positive effects might be restricted to the small areas of streambed covered by GCS. Improved understanding of GCS effects at both local and ecosystem scales is essential for stream management when these structures are present. Copyright ?? 2007 John Wiley & Sons, Ltd.

  2. A Benthic Macroinvertebrate Multimetric Index for Assessment of the Ecological Integrity of Northeast Streams, Thailand

    Directory of Open Access Journals (Sweden)

    Nantiya Rattanachan

    2016-07-01

    Full Text Available This study aims to develop a benthic macroinvertebrate multimetric index for assessing the ecological quality of streams in Northeastern Thailand. ANOSIM indicated that the benthic macroinvertebrate assemblage in both of each basin and each season were not significantly different (R = 0.09, p = 0.24 and R = 0.07, p = 0.35, respectively. The efficacy metrics of each basin consisting of the Mekong II, the Chi, and the Mun basins were integrated and calibrated. A total of 255 data sets of water physico-chemical and benthic macroinvertebrates during the dry period (cool and hot seasons were obtained. The stream classification could be divided into three groups: the reference group (48 stations, the stressed group (42 stations, and the intermediate group (165 stations. Twelve out of 56 metrics have been considered as a core metric for the development of a biological index for quality streams in the Northeast, including Total taxa, EPT taxa, Ephemeroptera taxa, Coleoptera taxa, % EPT, % Chironomidae, % Tolerant individuals, % Intolerant individuals, Beck's index, HBI, Predator taxa, and Clinger taxa. Moreover, this metric set covered the structure and function of organisms including the diversity of species, community structure, tolerance/intolerance measures, functional feeding group, and habit. From the efficacy validation of the biological index, the results of stream assessment corresponded to the classification sites with the physico-chemical characteristics.

  3. Assessment tools for urban catchments: developing biological indicators based on benthic macroinvertebrates

    Science.gov (United States)

    Purcell, A.H.; Bressler, D.W.; Paul, M.J.; Barbour, M.T.; Rankin, E.T.; Carter, J.L.; Resh, V.H.

    2009-01-01

    Biological indicators, particularly benthic macroinvertebrates, are widely used and effective measures of the impact of urbanization on stream ecosystems. A multimetric biological index of urbanization was developed using a large benthic macroinvertebrate dataset (n = 1,835) from the Baltimore, Maryland, metropolitan area and then validated with datasets from Cleveland, Ohio (n = 79); San Jose, California (n = 85); and a different subset of the Baltimore data (n = 85). The biological metrics used to develop the multimetric index were selected using several criteria and were required to represent ecological attributes of macroinvertebrate assemblages including taxonomic composition and richness (number of taxa in the insect orders of Ephemeroptera, Plecoptera, and Trichoptera), functional feeding group (number of taxa designated as filterers), and habit (percent of individuals which cling to the substrate). Quantile regression was used to select metrics and characterize the relationship between the final biological index and an urban gradient (composed of population density, road density, and urban land use). Although more complex biological indices exist, this simplified multimetric index showed a consistent relationship between biological indicators and urban conditions (as measured by quantile regression) in three climatic regions of the United States and can serve as an assessment tool for environmental managers to prioritize urban stream sites for restoration and protection.

  4. Land Use Influences Niche Size and the Assimilation of Resources by Benthic Macroinvertebrates in Tropical Headwater Streams.

    Directory of Open Access Journals (Sweden)

    Diego Marcel Parreira de Castro

    Full Text Available It is well recognized that assemblage structure of stream macroinvertebrates changes with alterations in catchment or local land use. Our objective was to understand how the trophic ecology of benthic macroinvertebrate assemblages responds to land use changes in tropical streams. We used the isotope methodology to assess how energy flow and trophic relations among macroinvertebrates were affected in environments affected by different land uses (natural cover, pasture, sugar cane plantation. Macroinvertebrates were sampled and categorized into functional feeding groups, and available trophic resources were sampled and evaluated for the isotopic composition of 13C and 15N along streams located in the Cerrado (neotropical savanna. Streams altered by pasture or sugar cane had wider and more overlapped trophic niches, which corresponded to more generalist feeding habits. In contrast, trophic groups in streams with native vegetation had narrower trophic niches with smaller overlaps, suggesting greater specialization. Pasture sites had greater ranges of resources exploited, indicating higher trophic diversity than sites with natural cover and sugar cane plantation. We conclude that agricultural land uses appears to alter the food base and shift macroinvertebrate assemblages towards more generalist feeding behaviors and greater overlap of the trophic niches.

  5. Land Use Influences Niche Size and the Assimilation of Resources by Benthic Macroinvertebrates in Tropical Headwater Streams

    Science.gov (United States)

    Parreira de Castro, Diego Marcel; Reis de Carvalho, Débora; Pompeu, Paulo dos Santos; Moreira, Marcelo Zacharias; Nardoto, Gabriela Bielefeld; Callisto, Marcos

    2016-01-01

    It is well recognized that assemblage structure of stream macroinvertebrates changes with alterations in catchment or local land use. Our objective was to understand how the trophic ecology of benthic macroinvertebrate assemblages responds to land use changes in tropical streams. We used the isotope methodology to assess how energy flow and trophic relations among macroinvertebrates were affected in environments affected by different land uses (natural cover, pasture, sugar cane plantation). Macroinvertebrates were sampled and categorized into functional feeding groups, and available trophic resources were sampled and evaluated for the isotopic composition of 13C and 15N along streams located in the Cerrado (neotropical savanna). Streams altered by pasture or sugar cane had wider and more overlapped trophic niches, which corresponded to more generalist feeding habits. In contrast, trophic groups in streams with native vegetation had narrower trophic niches with smaller overlaps, suggesting greater specialization. Pasture sites had greater ranges of resources exploited, indicating higher trophic diversity than sites with natural cover and sugar cane plantation. We conclude that agricultural land uses appears to alter the food base and shift macroinvertebrate assemblages towards more generalist feeding behaviors and greater overlap of the trophic niches. PMID:26934113

  6. Land Use Influences Niche Size and the Assimilation of Resources by Benthic Macroinvertebrates in Tropical Headwater Streams.

    Science.gov (United States)

    Parreira de Castro, Diego Marcel; Reis de Carvalho, Débora; Pompeu, Paulo dos Santos; Moreira, Marcelo Zacharias; Nardoto, Gabriela Bielefeld; Callisto, Marcos

    2016-01-01

    It is well recognized that assemblage structure of stream macroinvertebrates changes with alterations in catchment or local land use. Our objective was to understand how the trophic ecology of benthic macroinvertebrate assemblages responds to land use changes in tropical streams. We used the isotope methodology to assess how energy flow and trophic relations among macroinvertebrates were affected in environments affected by different land uses (natural cover, pasture, sugar cane plantation). Macroinvertebrates were sampled and categorized into functional feeding groups, and available trophic resources were sampled and evaluated for the isotopic composition of 13C and 15N along streams located in the Cerrado (neotropical savanna). Streams altered by pasture or sugar cane had wider and more overlapped trophic niches, which corresponded to more generalist feeding habits. In contrast, trophic groups in streams with native vegetation had narrower trophic niches with smaller overlaps, suggesting greater specialization. Pasture sites had greater ranges of resources exploited, indicating higher trophic diversity than sites with natural cover and sugar cane plantation. We conclude that agricultural land uses appears to alter the food base and shift macroinvertebrate assemblages towards more generalist feeding behaviors and greater overlap of the trophic niches. PMID:26934113

  7. Spatial and temporal variability of mobile macro-invertebrate assemblages associated to coralligenous habitat

    Directory of Open Access Journals (Sweden)

    R. BEDINI

    2014-07-01

    Full Text Available The study aimed to investigate patterns of spatial and temporal variability of mobile macroinvertebrate assemblages associated to coralligenous habitat. A multi-factorial sampling design was used to test the hypotheses that the structure of assemblages and their spatial and temporal variability changed in relation to substrate inclination. Moreover, macroalgae and sessile macro-invertebrates were also investigated in order to detect eventual relationship between sessile and mobile assemblages. A total of 236 mobile macro-invertebrate taxa were identified, among them 2 Platyhelminthes, 4 Sipuncula, 6 Nemertea, 27 Mollusca, 86 Annelida, 103 Arthropoda, 8 Echinodermata. Results of the study showed that mobile macro-invertebrate assemblages of coralligenous habitat were little influenced by the inclination of substrate and by the morphology of sessile organisms, as patterns of variation were different between the two assemblages. Mobile macro-invertebrate assemblages changed among sampling dates within one year period and they showed high variability at the spatial scale examined.

  8. Effects of acid mine drainage on water, sediment and associated benthic macroinvertebrate communities

    International Nuclear Information System (INIS)

    The toxic constituents of abandoned mined land (AML) discharges (acidic pH, heavy metals, total suspended solids) are extremely toxic to aquatic life . Studies were undertaken to ascertain environmental impacts to the upper Powell River, Lee and Wise Counties, Va. These impacts included disruptions in physical water quality, sediment quality, altered benthic macroinvertebrate assemblages, and toxicity of the water column and sediments from short-term impairment bioassays, and the potential to bioaccumulate selected metals (Al, Fe, Mn, P, Zn, Cu, Mg, S, Ni, Cd) by periphyton and resident bivalves. Water chemistry and macroinvertebrate assemblages were collected at upstream control, just below acid mine drainage and other downstream sites. Selected trace metal concentrations (Al, Fe, Mn, P, Zn, Cu, Mg, S, Ni, Cd) were determined for water, sediment and resident bivalves using ICP-AES. Acidic pH ranged from 2.15--3.3 at three AML-influenced seeps and varied from 6.4--8.0 at reference stations. At one AML-influenced creek, acidic pH conditions worsened from summer to fall and eradicated aquatic life throughout a 1.5 km stretch of that creek as it flowed into another creek. An additional dilution of 3.4 km in the second creek was needed to nearly neutralize the acidic pH problem. Conductivity (umhos/cm) ranged from 32--278 at reference sites and from 245--4,180 at AML-impact sites. Benthic macroinvertebrate abundance and taxon richness were essentially eliminated in the seeps or reached numbers of 1 -3 taxa totaling < 10 organisms relative to reference areas where richness values were 12--17 and comprised 300--977 organisms. Concentrations of Fe, Al, Mg and Cu and Zn were highest in the environmentally stressed stations of low pH and high conductivity relative to the reference stations. Iron was, by far, the element in highest concentration followed by Al and Mg

  9. Effects of engineered application of Eichhornia crassipes on the benthic macroinvertebrate diversity in Lake Dianchi, an ultra-eutrophic lake in China.

    Science.gov (United States)

    Zhang, Zhiyong; Wang, Zhi; Zhang, Zhenghua; Zhang, Junqian; Guo, Junyao; Li, Enhua; Wang, Xuelei; Liu, Haiqin; Yan, Shaohua

    2016-05-01

    An ecological engineering project with confined growth of 1.5 km(2) of Eichhornia crassipes was implemented to remove pollutants in Lake Dianchi. To assess the ecological effects of this project on benthic macroinvertebrate assemblages, a 1-year investigation at the areas inside and outside E. crassipes mats was conducted from May 2013 to May 2014. All the 10 sampling sites in the areas were grouped into two statistically significant clusters mainly corresponding to inside and outside E. crassipes mat areas (EMAs), by clustering analysis. E. crassipes reduced the densities of pollution indicator taxa (e.g., Oligochaeta and Chironomidae larvae); thus, the total densities of benthic macroinvertebrates at the area inside EMAs (mean 328.2 ind./m(2)) were slightly lower than that at the area outside EMAs (mean 505.6 ind./m(2)). Four functional feeding groups including 38 species of benthic macroinvertebrates were collected at the area inside EMAs, while only three functional feeding groups containing 17 species were collected at the area outside EMAs. The biodiversity indices (Shannon-Weiner, Margalef, Simpson, and Peilou indices) and K-dominance curves also showed higher diversity of benthic macroinvertebrates at the area inside EMAs than at the area outside EMAs. These results suggested that a certain scale of engineering application of E. crassipes was beneficial to benthic macroinvertebrate communities in the ultra-eutrophic Lake Dianchi and it could be used as a pioneer species in ultra-eutrophic lake for pollutant removal. PMID:26780060

  10. Impact of extreme oxygen consumption by pollutants on macroinvertebrate assemblages in plain rivers of the Ziya River Basin, north China.

    Science.gov (United States)

    Ding, Yuekui; Rong, Nan; Shan, Baoqing

    2016-07-01

    The aim of the study was to estimate the impact of oxygen depletion on macroinvertebrate community structure in benthic space. Macroinvertebrate assemblages and potential of dissolved oxygen (DO) consumption were investigated simultaneously in the plain rivers of the Ziya River Basin. The degree of DO depletion was represented by sediment oxygen demand (SOD) and DO, chemical oxygen demand (CODCr), and ammonia nitrogen (NH4 (+)-N) in the overlying water. The results showed an all-around hypoxia environment formed, and the values of DO, SOD, CODCr, and NH4 (+)-N were separately 0.11-4.03 mg L(-1), 0.41-2.60 g m(-2) day(-1), 27.50-410.00 mg L(-1), and 1.79-101.41 mg L(-1). There was an abnormal macroinvertebrate assemblage, and only 3 classes, Insecta, Gastropoda, and Oligochaeta, were found, which included 9 orders, 30 families, and 54 genera. The biodiversity was at a low level, and Shannon-Wiener index was 0.00-1.72. SOD, and NH4 (+)-N had major impact on the macroinvertebrate community, and the former had negative effect on most taxa, for instance, Nais, Branchiura, Paraleptophlebia, etc., which were sensitive or had a moderate-high tolerance to pollution. NH4 (+)-N had both positive and negative impacts on benthic animals, for instance, Dicrotendipes, Gomphus, Cricotopus, etc., for the former, and Procladius, Limnodrilus, Hippeutis, etc., for the latter. They all had a moderate-high tolerance to pollution. It is significant to improve DO condition and macroinvertebrate diversity in river harnessing and management. PMID:27048327

  11. Benthic macroinvertebrate richness along Sausal Creek, Oakland, California

    Science.gov (United States)

    Lara, D.; Ahumada, E.; Leon, Y.; Bracho, H.; Telles, C.

    2012-12-01

    Sausal Creek, 5.0 km long, is one of the principal watercourses in Oakland, California. The headwaters of Sausal Creek arise in the Oakland Hills and the creek flows southwestward through the city, discharging into the tidal canal that separates the island of Alameda from Oakland; the creek ultimately flows into San Francisco Bay. Due to the presence of rainbow trout, the stream health of Sausal Creek is a local conservation priority. In the present study, a survey of benthic macroinvertebrates in the creek was conducted and possible correlations between environmental variables and taxonomic richness were analyzed. Three stations along the creek were sampled using a 30.5cm 500 micron aquatic d-net, and temperature, pH and dissolved oxygen levels were measured in creek samples obtained at each station. Temperature, pH and dissolved oxygen levels remained constant along the creek. Taxonomic richness was highest at the upstream site of Palo Seco, located in an eastern section of the creek, and furthest downstream at Dimond Park, in the western portion of the creek. The Monterrey site, just west of Palo Seco was found to be significantly low in benthic macroinvertebrates. The Palo Seco and Monterrey sites are separated by Highway 13 and storm drain inputs may bring contaminants into the creek at this site. At the Monterrey site Sausal Creek follows the Hayward Fault, gas emissions or change in substrate may also affect the local population of benthic invertebrates. Further research will be conducted to determine what factors are contributing to this local anomaly.

  12. Patrones de distribución espacial de ensambles de macroinvertebrados bentónicos de un sistema fluvial Andino Patagónico Spatial distribution patterns of benthic macroinvertebrates assemblages in an Andean Patagonian fluvial system

    Directory of Open Access Journals (Sweden)

    CAROLINA MOYA

    2009-01-01

    Full Text Available En enero de 2006 se estudiaron los patrones espaciales de distribución de comunidades de macroinvertebrados bentónicos de la cuenca hidrográfica del río Baker (45°50' O y 47°55' S y los principales factores controladores, intentando cubrir la mayor variedad de ecosistemas lóticos. Para llevar a cabo el estudio se seleccionaron 27 estaciones de muestreo ubicadas en las diferentes subcuencas del río. En cada estación se realizó una caracterización fisicoquímica del agua (conductividad, oxígeno disuelto, pH, temperatura y turbidez, y se documentaron las características del tramo de río (e.g. ancho del cauce y tipo de sedimento e información cartográfica utilizando un sistema de información geográfica (SIG. Se identificaron un total de 51 taxa que correspondieron en su mayoría a larvas de insectos (80 %. Los grupos con mayor riqueza fueron los órdenes Ephemeroptera (15 taxa, Plecoptera (8 taxa y Trichoptera (8 taxa. Los análisis de clasificación y ordenación realizados con los datos de abundancia, permitieron reconocer siete grupos de estaciones diferentes (A-F que fueron estadísticamente significativos (P In January of 2006 we studied the distributional patterns of benthic macroinvertebrate communities of the Baker river basin (45°50' O and 47°55' S and their main controlling factors trying to cover the greater variety of the lotic ecosystems. To carry out the study, 27 sampling stations were located in the different sub basins of the river. In each station, physical-chemical parameters of the column of water were quantified (conductivity, dissolved oxygen, pH, temperature and turbidity, and documented characteristics of the segment (e.g. wide of the channel and sediment type and cartographic information using a geographic information system (GIS and complemented with cartographic information using GIS. Identified a total of 51 taxa, are mostly insect larvae (80 %. The groups most richness were orders Ephemeroptera (15

  13. A bioassessment of lakes in the Athabasca Oil Sands Region, Alberta, using benthic macroinvertebrates

    Directory of Open Access Journals (Sweden)

    Keith M. SOMERS

    2010-08-01

    Full Text Available Emissions of sulphur oxides, nitrogen oxides and other pollutants have increased in the Athabasca Oil Sands Region (AOSR in Alberta, Canada. Atmospheric pollutants impact aquatic communities through a number of processes, but due to a lack of regional monitoring programs potential biological impacts have not been assessed. In this study, a bioassessment was conducted using approaches borrowed from a variety of protocols to establish a baseline dataset, determine appropriate methodologies, and to assess the current impact of emissions on benthic macroinvertebrate (BMI communities in the AOSR. As a result, 32 lakes, including 5 test lakes located in a modelled high deposition region, were sampled for water chemistry and BMI. The Reference Condition Approach (RCA was used because a baseline dataset does not exist and data were evaluated using three separate statistical techniques. All of the statistical methods used: One Sample T-Tests, Multivariate Analysis of Variance (MANOVA and Test Site Analysis (TSA, showed that BMI assemblages in test lakes differed from BMI assemblages in reference lakes. Traditional statistics classified all 5 test lakes as "significantly impaired" whereas TSA identified 3 of the 5 test lakes as only potentially impaired and 2 lakes were in "reference condition". The variability in lake attributes present challenges in interpreting BMI data and establishing an accurate biomonitoring program in the AOSR which need to be addressed in future assessment studies.

  14. Benthic macroinvertebrates diversity and water quality assessment at Sungai Congkak recreational area, Hulu Langat, Selangor

    Science.gov (United States)

    Mustaqim-Alias, M.; Ahmad, A. K.

    2013-11-01

    A study on benthic macroinvertebrates diversity and water quality assessment was conducted at Sungai Congkak recreational area in Hulu Langat, Selangor. Sums of eight sampling stations were selected with a distance of 100-200 m interval between each station. Benthic macroinvertebrates was sampled using a Surber net, while water sampling and analysis were undertaken according to HACH standard methods. A total of 3754 individuals from 40 families of benthic macroinvertebrates were recorded at this river. Ecological indices namely Shannon diversity index (2.49), Pielou evenness index (0.77) and Margalef richness index (4.06) demonstrate that Sungai Congkak is at good condition and benthic macroinvertebrates has homogeneous distribution along the sampling sites. Elmidae, Hydrophilidae, Baetidae and Perlidae were most dominant families present in that area and adapted progressively with excellent water quality (> 300 individuals). As regards to Malaysian's Water Quality Index (WQI), the study area at Sungai Congkak is classified in class I which has good water quality conditions. The Pearson correlation test indicates that ecological indices have strong correlation toward WQI at all sampling stations. As a conclusion, the benthic macroinvertebrates and WQI data demonstrated that Sungai Congkak is clean and suitable as recreational stream based on this study.

  15. Physical variables influencing macro-invertebrate assemblages in epiphytic bromeliads in the rain forest of Belize

    OpenAIRE

    Urrutia, Jose Joaquin

    2011-01-01

    Epiphytic bromeliads from the genus Aechmea are found on many different tree species in the tropics. These bromeliads have evolved water storage tanks where they are able to host many different macro-invertebrate species. The aim of the present study was to assess if six physical variables: i) tree height, ii) tree width, iii) bromeliad weight, iv) bromeliad longest leaf length, v) bromeliad temperature and vi) bromeliad position, have an effect on macro-invertebrate assemblage...

  16. Effect of riparian vegetation cover and season on aquatic macroinvertebrate assemblages in the Ecuadorian Andes

    OpenAIRE

    Gallegos-Sánchez, Silvana Andrea

    2013-01-01

    The purpose of this study was to investigate the effects of season and changes in the riparian vegetation cover on diversity, structure, temporal variability, and trophic structure of aquatic macroinvertebrate assemblage in the Sambache River, Pasochoa Wildlife Refuge, Ecuador. Macroinvertebrate samples were collected using a Surber bottom sampler during the dry and rainy seasons from sections of the river dissecting three different riparian vegetation types with varying degrees of disturbanc...

  17. Studying the movement behaviour of benthic macroinvertebrates with automated video tracking

    OpenAIRE

    Augusiak, J.A.; Brink, van den, L.

    2015-01-01

    Quantifying and understanding movement is critical for a wide range of questions in basic and applied ecology. Movement ecology is also fostered by technological advances that allow automated tracking for a wide range of animal species. However, for aquatic macroinvertebrates, such detailed methods do not yet exist. We developed a video tracking method for two different species of benthic macroinvertebrates, the crawling isopod Asellus aquaticus and the swimming fresh water amphipod Gammarus ...

  18. Ecological studies of benthic macroinvertebrates for determining sedimentation impacts in Chattahoochee National Forest streams

    OpenAIRE

    Longing, Scott Douglas

    2006-01-01

    Understanding sedimentation impacts to benthic macroinvertebrates in headwater, mountain streams is a top priority of watershed management programs in the Chattahoochee National Forest. Five studies involving the analysis of historical, biological survey data and current data were conducted to improve our understanding of macroinvertebrate response to sedimentation and to support the development of biological information for sediment load models to be applied in the Chattooga River watershed...

  19. Successional trends of the benthic macroinvertebrate community in a new southeastern cooling reservoir

    International Nuclear Information System (INIS)

    Lakes created by river impoundments provide new lentic habitats for benthic macroinvertebrates. As new lakes age, benthic macroinvertebrate succession proceeds as first colonizers are replaced and stable populations eventually become established. L Lake, a 400 ha reservoir, was constructed in 1985 on the Department of Energy's Savannah River Site in South Carolina to receive heated effluent from a nuclear production reactor. Benthic macroinvertebrates were collected in L Lake with a ponar grab sampler at 2 and 4 meters at 10 locations in 5 lake regions. Monthly collections were made from 1986 through 1989. Annual average densities of benthic macroinvertebrates increased substantially during the study (ranging from 3955.5--4471.6 organisms/m2 in 1986 to 8948.1--11,694.1 organisms/m2 in 1988). Annual mean biomass also increased (ranging from 0.749--0.907g AFDM/m2 in 1986 to 2074--11,322 g AFDM/m2 in 1988). Mean annual taxa richness ranged from 9.3--12.2 per ponar in 1986 to 11.8--15.3 per ponar in 1988. Some early colonizers (Chironomidae: Chironomini) dominated throughout the study (ranging from 60.3--79.1% of all organisms). Other chironomids (Tanytarsini and Tanypodinae) declined while slower colonizers (oligochaetes and nematodes) generally increased from 1986 through 1988. The increases in macroinvertebrate density, biomass and changes in community composition observed are typical of early reservoir succession. 14 refs., 12 figs., 1 tab

  20. Explaining dissimilarities in macroinvertebrate assemblages among stream sites using environmental variables

    Directory of Open Access Journals (Sweden)

    Adriano S. Melo

    2009-03-01

    Full Text Available The relationship between community structure and environmental factors usually varies according to ecosystem type, group of organisms, and spatial scale. In this study I assessed whether dissimilarities among assemblages of stream macroinvertebrates are related to differences in environmental variables. Data consisted of macroinvertebrate samples of 10 stream sites during the dry season. Seven environmental variables were assessed. The relationship among dissimilarities in assemblage structure and dissimilarities in environmental variables was assessed using the BioEnv approach. Conductivity and measures related to stream size were the most important variables. However, part of the correlation with conductivity was due to the high value observed in a single stream site, which presented a relatively distinct macroinvertebrate fauna. There was an abrupt change in assemblage structure between 4th and 5th order streams. Although the study included a single 5th order site and thus only weak generalizations are possible, this finding corroborates scattered evidence observed in previous studies. The finding that nearby sites may harbor distinct macroinvertebrate assemblages implies whole-catchment conservation strategies. As most of the remaining Atlantic Rain Forest is restricted to small fragments, restoration projects near fragments should be implemented so as to properly conserve lotic ecosystems.

  1. Relationships between lake water chemistry and benthic macroinvertebrates in the Athabasca Oil Sands Region, Alberta

    Directory of Open Access Journals (Sweden)

    Keith M. SOMERS

    2010-08-01

    Full Text Available Sulphur and nitrogen emissions in the Athabasca Oil Sands Region (AOSR are a threat to regional lentic ecosystems. Benthic macroinvertebrates have been used successfully elsewhere to monitor the impacts of acid emissions on water bodies and the opportunity exists to implement a regional lentic biomonitoring program in the AOSR. Metrics are often used to assess the impacts of anthropogenic stressors because they describe biological conditions through a variety of measures. The selection of appropriate metrics is an integral component of any biomonitoring program and it depends on the in situ relationships between water chemistry and benthic macroinvertebrates. In order to establish these relationships we compared lake water chemistry parameters with benthic macroinvertebrate communities and metric scores from 32 lakes in the AOSR through Redundancy Analyses. Lake acidity correlates positively with Hyallelidae and negatively with Chironomidae and Oligochaeta while dissolved organic carbon is also an important determinant of benthic macroinvertebrate community composition. A number of metrics were strongly correlated with lake acidity and the following compositional metrics proved to be the most suitable for monitoring acidification in the AOSR: % Diptera, % Oligochaeta, % EPT, Total Ephemeroptera and Total Trichoptera.

  2. Water Quality Assessment Using Benthic Macroinvertebrates in a Periurban Stream (Cameroon)

    OpenAIRE

    Foto Menbohan S; Tchakonte S; Ajeagah Gideon A; Zebaze Togouet S. H; Bilong Bilong C.F.; Njiné T

    2013-01-01

    In order to assess the water quality of Nga stream, the right tributary of Mefou, physicochemical variables were coupled to benthic macroinvertebrates communities. Physicochemical results revealed a good health status of the Nga stream, with significant differences of conductivity observed between stations and months (P

  3. Anthropogenic disturbance and landscape patterns affect diversity patterns of aquatic benthic macroinvertebrates

    Science.gov (United States)

    Maloney, K.O.; Munguia, P.; Mitchell, R.M.

    2011-01-01

    Measures of species diversity are valuable tools for assessing ecosystem health. However, most assessments have addressed individual sites or regional taxon pools, with few comparisons of differences in assemblage composition within or among regions. We examined the effects of anthropogenic disturbance on local richness (?? diversity) and species turnover (?? diversity) of benthic macroinvertebrates in small streams within and between 2 ecoregions (Northern Piedmont vs Southeastern Plains ecoregions) of the Patuxent River basin (Maryland, USA). Regional species pools did not differ between ecoregions (Piedmont = 166 taxa, Plains = 162 taxa); however, local richness was lower in the Plains (mean = 17.4 taxa/stream) compared to the Piedmont (mean = 22.2 taxa/stream). When streams were categorized into disturbance classes (low, medium, high), local richness did not differ among categories for either region. However, at the entire Patuxent scale, local richness tended to decrease with % impervious cover in a watershed. Variation in species composition, analyzed with nonmetric multidimensional scaling (nMDS), differed significantly between Piedmont and Plains streams, and Plains streams had higher ?? diversity than Piedmont streams. When partitioned by disturbance category and region, ?? diversity differed only between the low-disturbance sites (Plains > Piedmont). Relationships between ?? diversity and environmental variables varied by region. ?? diversity was weakly negatively related to % row-crop cover in a watershed at the entire Patuxent scale. For the Piedmont region, ?? diversity tended to decrease with % forest, % pasture, and % row-crop cover in a watershed. Such negative relationships between ?? diversity and landuse variables indicate a possible homogenization of the assemblage. The incongruence between diversity measures and composition measures, together with differing effects of anthropogenic land use on ?? diversity in the 2 regions, emphasizes the need

  4. Length-mass relationships for transitional water benthic macroinvertebrates in Mediterranean and Black Sea ecosystems

    Science.gov (United States)

    Rosati, I.; Barbone, E.; Basset, A.

    2012-11-01

    Length-mass relationships are potentially useful tools to estimate individual biomass, assuming a relative invariance within and among populations and, sometimes, among species pertaining to a same family or order. Here, we present a field test of these assumptions in guilds of benthic macroinvertebrates colonising transitional water ecosystems. To this aim, we are analysing length-mass relationships of benthic macroinvertebrates of transitional water ecosystems and assessing their variability among populations of a same species and among species of a same family and/or order. Data are from synoptic studies carried out at four oligohaline transitional water ecosystems, from the Southern Italy and the Danube delta ecoregions; they refer to 40 macroinvertebrate taxa selected from the overall species pool according to absolute and relative density requirements. Species composition differed widely among ecoregions while length-mass relationships of the species occurring in both ecoregions did not; the variability of length-mass parameters of these species among ecosystems was lower than 10%. Length-mass regressions were relatively conservative also with respect to taxonomic resolution; significant differences were observed among species within 5 out of the 7 orders tested but differences in slopes and intercepts were on average lower than 15%. Therefore, our results, representing one of the first efforts to catalogue length-mass relationships for benthic macroinvertebrates in transitional waters, support the assumption of relative invariance of length-mass relationships and their use in studies where gross estimates of population biomasses are required.

  5. Ultraviolet-B-driven pigmentation and genetic diversity of benthic macroinvertebrates from high-altitude Andean streams

    NARCIS (Netherlands)

    R.A. Loayza Muro; J.K. Marticorena-Ruíz; E.J. Palomino; C Merrit; J.A.J. Breeuwer; P. Kuperus; M.H.S. Kraak; W. Admiraal

    2013-01-01

    Photoprotective pigments in benthic macroinvertebrates may reduce the damage caused by the blistering UV-B radiation in Andean high-altitude streams above 3500 m. The aim of this study was therefore to determine whether melanisation in macroinvertebrates inhabiting high-altitude Andean streams is an

  6. Mesohabitat-specific Macroinvertebrate Assemblage Responses to Water Quality Variation in Mid-continent (North America) Great Rivers

    Science.gov (United States)

    We compared the responsiveness of macroinvertebrate assemblages to water quality stressors (ions, nutrients, dissolved metals and suspended sediment) in two mesohabitats within the main-channel macrohabitat of three mid-continent North American rivers, the Upper Mississippi, Miss...

  7. Benthic Macroinvertebrates along the Haraz Downstream in Southern Caspian Sea Basin: In Gradient of the Physicochemical Parameters

    OpenAIRE

    Amir Faraz Ghasemi; Morteza Kamali

    2014-01-01

    The Haraz River is one of the most important rivers in the Caspian Sea basin. In order to investigate changes in the taxa abundance composition and feeding groups of the benthic macroinvertebrates, twelve-time sampling was carried out at nine stations along three different sites: (1) before, (2) into, and (3) after Amol City. Results showed impacts of anthropogenic activities caused by the urbanization and development on the occurrence of benthic macroinvertebrates taxa. Families, Hydropsychi...

  8. Biodiversity assessment of benthic macroinvertebrates in altitudinal lotic ecosystems of Serra do Cipó (MG, Brazil)

    OpenAIRE

    GALDEAN N.; Callisto, M.; F. A. R. BARBOSA

    2001-01-01

    Five lotic systems of Serra do Cipó, south-east Brazil, were investigated in order to assess the existing diversity of benthic macroinvertebrates, habitats-microhabitats, and the available trophic resources. For each river it was analysed the communities of benthic macroinvertebrates and the composition of some taxonomic groups (Plecoptera, Ephemeroptera, Trichoptera and Diptera Chironomidae): the community with Bivalvia Sphaeriidae, Oligochaeta and Ephemeroptera Baetidae (being supposed a cl...

  9. Spatial-temporal variability in water quality and macro-invertebrate assemblages in the Upper Mara River basin, Kenya

    Science.gov (United States)

    Kilonzo, Fidelis; Masese, Frank O.; Van Griensven, Ann; Bauwens, Willy; Obando, Joy; Lens, Piet N. L.

    Tropical rivers display profound temporal and spatial heterogeneity in terms of environmental conditions. This aspect needs to be considered when designing a monitoring program for water quality in rivers. Therefore, the physico-chemical composition and the nutrient loading of the Upper Mara River and its two main tributaries, the Amala and Nyangores were monitored. Initial daily, and later a weekly monitoring schedule for 4 months spanning through the wet and dry seasons was adopted. Benthic macro-invertebrates were also collected during the initial sampling to be used as indicators of water quality. The aim of the current study was to investigate the physico-chemical status and biological integrity of the Upper Mara River basin. This was achieved by examining trends in nutrient concentrations and analyzing the structure, diversity and abundance of benthic macro-invertebrates in relation to varying land use patterns. Sampling sites were selected based on catchment land use and the level of human disturbance, and using historical records of previous water quality studies. River water pH, dissolved oxygen, electrical conductivity (EC), temperature, and turbidity were determined in situ. All investigated parameters except iron and manganese had concentration values within allowable limits according to Kenyan and international standards for drinking water. The Amala tributary is more mineralized and also shows higher levels of pH and EC than water from the Nyangores tributary. The latter, however, has a higher variability in both the total phosphorus (TP) and total nitrogen (TN) concentrations. The variability in TP and TN concentrations increases downstream for both tributaries and is more pronounced for TN than for TP. Macro-invertebrate assemblages responded to the changes in land use and water quality in terms of community composition and diversity. The study recommends detailed continuous monitoring of the water quality at shorter time intervals and to identify

  10. Effects of agricultural and urban impacts on macroinvertebrates assemblages in streams (Rio Grande do Sul, Brazil

    Directory of Open Access Journals (Sweden)

    Luiz Ubiratan Hepp

    2010-02-01

    Full Text Available This study evaluates the effects of agricultural and urban activities on the structure and composition of benthic communities of streams in the state of Rio Grande do Sul, Brazil. Benthic macroinvertebrates were collected in streams influenced by urbanization and agriculture and in streams with no anthropogenic disturbances (reference streams. Organism density was superior in urban streams when compared with streams in the other two areas. The taxonomic richness and Shannon diversity index were higher in reference streams. The benthic fauna composition was significantly different among land uses. The classification and ordination analyses corroborated the results of variance analyses demonstrating the formation of clusters corresponding to streams with similar land use. Seasonality was also found to influence the benthic community, though in a lesser degree than land use.

  11. Benthic macroinvertebrates as ecological indicators for estuarine and coastal ecosystems : assessment and intercalibration

    OpenAIRE

    Teixeira, Heliana Lilita Gonçalves

    2010-01-01

    The aim of the research work presented in this thesis is to be a contribution to the field of ecological assessment in coastal and transitional ecosystems. The main goals were: a) to present a method for the assessment of the ecological status of benthic macroinvertebrate communities in Portuguese transitional waters that would meet the requirements of the European Water Framework Directive (WFD); and b) to propose alternatives to harmonize ecological assessments, namely those ...

  12. Relationships between lake water chemistry and benthic macroinvertebrates in the Athabasca Oil Sands Region, Alberta

    OpenAIRE

    Keith M. SOMERS; Peter J Dillon; Shaun A. WATMOUGH; Brent G. PARSONS

    2010-01-01

    Sulphur and nitrogen emissions in the Athabasca Oil Sands Region (AOSR) are a threat to regional lentic ecosystems. Benthic macroinvertebrates have been used successfully elsewhere to monitor the impacts of acid emissions on water bodies and the opportunity exists to implement a regional lentic biomonitoring program in the AOSR. Metrics are often used to assess the impacts of anthropogenic stressors because they describe biological conditions through a variety of measures. The selection of ap...

  13. Spatial variation in lake benthic macroinvertebrate ecological assessment: a synthesis of European case studies

    DEFF Research Database (Denmark)

    Sandin, Leif Leonard; Solimini, Angelo G.

    2012-01-01

    This paper summarizes eight case studies that were analysed as part of the research theme ``lake benthic macroinvertebrates'' forming part of the EU-funded WISER project ``Water bodies in Europe: Integrative Systems to assess Ecological status and Recovery''. The relationships between lake benthi...... our aim is to provide useful information for designing monitoring programs and invertebrate based ecological classification tools with the ultimate aim to improve a sound management of European lake ecosystems....

  14. The role of physical habitat and sampling effort on estimates of benthic macroinvertebrate taxonomic richness at basin and site scales.

    Science.gov (United States)

    Silva, Déborah R O; Ligeiro, Raphael; Hughes, Robert M; Callisto, Marcos

    2016-06-01

    Taxonomic richness is one of the most important measures of biological diversity in ecological studies, including those with stream macroinvertebrates. However, it is impractical to measure the true richness of any site directly by sampling. Our objective was to evaluate the effect of sampling effort on estimates of macroinvertebrate family and Ephemeroptera, Plecoptera, and Trichoptera (EPT) genera richness at two scales: basin and stream site. In addition, we tried to determine which environmental factors at the site scale most influenced the amount of sampling effort needed. We sampled 39 sites in the Cerrado biome (neotropical savanna). In each site, we obtained 11 equidistant samples of the benthic assemblage and multiple physical habitat measurements. The observed basin-scale richness achieved a consistent estimation from Chao 1, Jack 1, and Jack 2 richness estimators. However, at the site scale, there was a constant increase in the observed number of taxa with increased number of samples. Models that best explained the slope of site-scale sampling curves (representing the necessity of greater sampling effort) included metrics that describe habitat heterogeneity, habitat structure, anthropogenic disturbance, and water quality, for both macroinvertebrate family and EPT genera richness. Our results demonstrate the importance of considering basin- and site-scale sampling effort in ecological surveys and that taxa accumulation curves and richness estimators are good tools for assessing sampling efficiency. The physical habitat explained a significant amount of the sampling effort needed. Therefore, future studies should explore the possible implications of physical habitat characteristics when developing sampling objectives, study designs, and calculating the needed sampling effort. PMID:27165604

  15. The impact of episodic coal mine drainage pollution on benthic macroinvertebrates in streams in the Anthracite region of Pennsylvania

    International Nuclear Information System (INIS)

    Episodic coal mine drainage, caused by fluctuations in mine discharges relative to stream flow, has devastating effects on aquatic macroinvertebrate communities. Seven stream reaches in the Anthracite region of Pennsylvania were identified as chronically, episodically or not impaired by mine drainage, and sampled seasonally for 1 year to determine the effect of episodic mine drainage on macroinvertebrates. Specific conductance fluctuated seasonally in episodic sites; it was lower in winter when discharge increased and higher in summer when discharges decreased and mine drainage made up a larger proportion of stream flow. Although we hypothesized that episodic streams would have higher macroinvertebrate richness than chronic streams, comparisons showed no differences in richness between treatments. Episodic pollution may result from undersized or poorly maintained passive treatment systems; therefore, intensive macroinvertebrate monitoring may be needed to identify streams being affected by episodic mine drainage because macroinvertebrate richness may be sensitive to water quality fluctuations. - Episodic coal mine pollution decreases benthic macroinvertebrate richness and density

  16. Field experiments on responses of a freshwater, benthic macroinvertebrate community to vertebrate predators

    International Nuclear Information System (INIS)

    The seasonal importance of vertebrate predators in potentially regulating the abundance and diversity of the benthic macroinvertebrates in the littoral zone of a soft-bottom reservoir that receives thermal effluent from a nuclear production reactor was examined. Thirty-six predator (fish and turtle) exclusion cages (4 m2) were placed in shallow water at six locations along a thermal gradient in Par Pond, a 1100-ha cooling reservoir on the Savannah River Plant near Aiken, South Carolina, USA. An additional 36 control plots (4 m2) were also set up. Cages were in place during three, 3-mo test periods beginning in September 1977. Estimates of benthic density, taxon richness, and distribution within functional groups (defined by feeding mechanism) were calculated for each test period. Effects of temperature on predator-prey relationships were also determined. Experimental results of this study suggest that vertebrate predation was not the fundamental parameter organizing the benthic macroinvertebrate community in the littoral zone of this reservoir. Neither taxon richness nor density of total macroinvertebrates was conclusively related to predator treatment. Relationships between predator treatment and community response (changes in density and taxon richness) were generally unaffected by either plot locality, temperature fluctuations from thermal effluent, or seasonal changes. When data from caged and control plots were pooled, however, both location and water temperature individually had direct impacts on the benthic community. From these results and other field studies it is hypothesized that individual species of keystone benthic predators do not occur in the littoral zone of freshwater lentic environments with soft bottoms

  17. L-Lake macroinvertebrate community

    Energy Technology Data Exchange (ETDEWEB)

    Specht, W.L.

    1996-06-01

    To characterize the present benthic macroinvertebrate community of L-Lake, Regions 5 and 7 of the reservoir were sampled in September 1995 at the same locations sampled in 1988 and 1989 during the L-Lake monitoring program. The macroinvertebrate community of 1995 is compared to that of 1988 and 1989. The species composition of L-Lake`s macroinvertebrate community has changed considerably since 1988-1989, due primarily to maturation of the reservoir ecosystem. L-Lake contains a reasonably diverse macroinvertebrate community that is capable of supporting higher trophic levels, including a diverse assemblage of fish species. The L-Lake macroinvertebrate community is similar to those of many other southeastern reservoirs, and there is no indication that the macroinvertebrate community is perturbed by chemical or physical stressors.

  18. L-Lake macroinvertebrate community

    International Nuclear Information System (INIS)

    To characterize the present benthic macroinvertebrate community of L-Lake, Regions 5 and 7 of the reservoir were sampled in September 1995 at the same locations sampled in 1988 and 1989 during the L-Lake monitoring program. The macroinvertebrate community of 1995 is compared to that of 1988 and 1989. The species composition of L-Lake's macroinvertebrate community has changed considerably since 1988-1989, due primarily to maturation of the reservoir ecosystem. L-Lake contains a reasonably diverse macroinvertebrate community that is capable of supporting higher trophic levels, including a diverse assemblage of fish species. The L-Lake macroinvertebrate community is similar to those of many other southeastern reservoirs, and there is no indication that the macroinvertebrate community is perturbed by chemical or physical stressors

  19. Macroinvertebrate assemblages in agricultural, mining, and urban tropical streams: implications for conservation and management.

    Science.gov (United States)

    Mwedzi, Tongayi; Bere, Taurai; Mangadze, Tinotenda

    2016-06-01

    The study evaluated the response of macroinvertebrate assemblages to changes in water quality in different land-use settings in Manyame catchment, Zimbabwe. Four land-use categories were identified: forested commercial farming, communal farming, Great Dyke mining (GDM) and urban areas. Macroinvertebrate community structure and physicochemical variables data were collected in two seasons from 41 sites following standard methods. Although not environmentally threatening, urban and GDM areas were characterised by higher conductivity, total dissolved solids, salinity, magnesium and hardness. Chlorides, total phosphates, total nitrogen, calcium, potassium and sodium were significantly highest in urban sites whilst dissolved oxygen (DO) was significantly higher in the forested commercial faming and GDM sites. Macroinvertebrate communities followed the observed changes in water quality. Macroinvertebrates in urban sites indicated severe pollution (e.g. Chironomidae) whilst those in forested commercial farming sites and GDM sites indicated relatively clean water (e.g. Notonemouridae). Forested watersheds together with good farm management practices are important in mitigating impacts of urbanisation and agriculture. Strategies that reduce oxygen-depleting substances must be devised to protect the health of Zimbabwean streams. The study affirms the wider applicability of the South African Scoring System in different land uses. PMID:26920532

  20. The impact of sediment removal on the aquatic macroinvertebrate assemblage in a fishpond littoral zone

    Directory of Open Access Journals (Sweden)

    Zdeněk ADÁMEK

    2011-02-01

    Full Text Available Bottom sediment removal, a widely used technique in restoration management of standing water bodies, has a strong influence on communities of aquatic organisms. As most information on the impact of sediment removal on the aquatic environment comes from studies on lakes, the aim of this study was to describe macroinvertebrate assemblage succession in a fishpond (Štěpánek fishpond, Bohemian-Moravian highlands, Czech Republic littoral zone following restoration by sediment removal during the winter of 2003/2004. Semi-quantitative hand net sampling was undertaken one year before (2003 and in each of the following five years (2004–2008 after sediment removal. A significant decrease in both abundance (approx. 90% of individuals and diversity (approx. 30% of taxa of macroinvertebrates was detected immediately after pond restoration. The values gradually increased over subsequent years, reaching comparable abundance and diversity three years after sediment removal. A significant shift was recorded in the taxonomic and functional composition of the macroinvertebrate assemblage after sediment removal. Mayfly larvae were the dominant invertebrates before restoration, while chironomid larvae and oligochaetes dominated after sediment removal. Phytophilous taxa, grazers and scrapers, and swimming or diving invertebrates were common in 2003, whilst open-water taxa preferring mud and other mostly inorganic microhabitats, gatherers/collectors, and burrowing/boring invertebrates were relatively common after sediment removal. In 2008, the assemblage reverted towards the situation before sediment removal, probably connected with a lower water level and accelerated macrophyte bed succession. Principal Component Analysis on the species data confirmed the differences in invertebrate taxonomic structure among sampling years. Succession of the fishpond invertebrate assemblage in the years following sediment removal was mainly influenced by fish farming practice and

  1. Spatial variability in macroinvertebrate assemblages along and among neighbouring equatorial glacier-fed streams

    DEFF Research Database (Denmark)

    Kuhn, J.; Andino, P.; Calvez, R.;

    2011-01-01

    Andes of Ecuador. Our main goals were (i) to determine overall longitudinal patterns in density, taxon richness and the composition of macroinvertebrate assemblages and driving factors in equatorial glacial streams and (ii) to examine variability among replicate streams in faunal metrics and assemblages...... sites, following a supposed decrease in environmental harshness along the streams. Relationships between faunal metrics and the four environmental variables mean temperature, the stability index, chlorophyll a and coarse particulate organic matter also varied among the three streams. Generalised linear...... and temperature and stability as main driving factors were met by our three replicate equatorial glacial streams. Qualitative departures from the model were mainly because of zoogeographical differences. We demonstrated that variability in assemblages between comparable sites in closely situated...

  2. Development of a local-scale urban stream assessment method using benthic macroinvertebrates: An example from the Santa Clara Basin, California

    Science.gov (United States)

    Carter, J.L.; Purcell, A.H.; Fend, S.V.; Resh, V.H.

    2009-01-01

    Research that explores the biological response to urbanization on a site-specific scale is necessary for management of urban basins. Recent studies have proposed a method to characterize the biological response of benthic macroinvertebrates along an urban gradient for several climatic regions in the USA. Our study demonstrates how this general framework can be refined and applied on a smaller scale to an urbanized basin, the Santa Clara Basin (surrounding San Jose, California, USA). Eighty-four sampling sites on 14 streams in the Santa Clara Basin were used for assessing local stream conditions. First, an urban index composed of human population density, road density, and urban land cover was used to determine the extent of urbanization upstream from each sampling site. Second, a multimetric biological index was developed to characterize the response of macroinvertebrate assemblages along the urban gradient. The resulting biological index included metrics from 3 ecological categories: taxonomic composition ( Ephemeroptera, Plecoptera, and Trichoptera), functional feeding group (shredder richness), and habit ( clingers). The 90th-quantile regression line was used to define the best available biological conditions along the urban gradient, which we define as the predicted biological potential. This descriptor was then used to determine the relative condition of sites throughout the basin. Hierarchical partitioning of variance revealed that several site-specific variables (dissolved O2 and temperature) were significantly related to a site's deviation from its predicted biological potential. Spatial analysis of each site's deviation from its biological potential indicated geographic heterogeneity in the distribution of impaired sites. The presence and operation of local dams optimize water use, but modify natural flow regimes, which in turn influence stream habitat, dissolved O2, and temperature. Current dissolved O2 and temperature regimes deviate from natural

  3. Non-indigenous macroinvertebrate species in Lithuanian fresh waters, Part 2: Macroinvertebrate assemblage deviation from naturalness in lotic systems and the consequent potential impacts on ecological quality assessment

    Directory of Open Access Journals (Sweden)

    Arbačiauskas K.

    2011-12-01

    Full Text Available The biological pressure represented by non-indigenous macroinvertebrate species (NIMS should be addressed in the implementation of EU Water Framework Directive as this can have a direct impact on the ’naturalness’ of the invaded macroinvertebrate assemblage. The biocontamination concept allows assessment of this deviation from naturalness, by evaluation of abundance and disparity contamination of an assemblage. This study aimed to assess the biocontamination of macroinvertebrate assemblages in Lithuanian rivers, thereby revealing the most high-impact non-indigenous species, and to explore the relationship between biocontamination and conventional metrics of ecological quality. Most of the studied rivers appeared to be impacted by NIMS. The amphipods Pontogammarus robustoides, Chelicorophium curvispinum and snail Litoglyphus naticoides were revealed as high-impact NIMS for Lithuanian lotic systems. Metrics of ecological quality which largely depend upon the richness of indicator taxa, such as the biological monitoring working party (BMWP score and Ephemeroptera/Plecoptera/Trichoptera (EPT taxa number, were negatively correlated with biocontamination, implying they could provide unreliable ecological quality estimates when NIMS are present. Routine macroinvertebrate water quality monitoring data are sufficient for generation of the biocontamination assessment and thus can provide supplementary information, with minimal extra expense or effort. We therefore recommend that biocontamination assessment is included alongside established methods for gauging biological and chemical water quality.

  4. Benthic macroinvertebrate as biological indicator for water quality in Sungai Penchala

    Science.gov (United States)

    Mahazar, Akmal; Shuhaimi-Othman, Mohammad; Kutty, Ahmad Abas

    2013-11-01

    Sungai Penchala is one of the main tributaries for Sungai Klang which flows through the urban area of Wilayah Persekutuan Kuala Lumpur before merging with Sungai Klang in the Petaling Jaya district. As urban river, Sungai Penchala is polluted because of anthropogenic activities and this include direct garbage load, untreated drainage system from nearby residential area and also runoff from frequent heavy rain as the country located in tropical area. Currently, there are efforts from government and educational sectors to monitor and rehabilitate the river with vision to return it into its former natural function and not as a sink for urban population. Unlike pristine or recreational river, the water quality of urban river changes drastically over day even hours. Thus there is need for a procedure that can be used for water quality inspection in time of sampling but also provides reliable information that can resemble past event. Therefore, to do that the river monitoring was carried out by employing the traditional physical-chemical parameter by using Hydrolab Quanta® multi parameter reader. The benthic macroinvertebrate was collected using Surber's sampler and preserved in 95% ethanol for identification purposes. The data collected was analyzed for Water Quality Index (WQI) and Biological Monitoring Working Party (BMWP) to determine the river condition. The system used has its own strength and weakness but when employed together, it is expected to give better knowledge in evaluating river condition. Thus, increase the accuracy of evaluation process. In this study, the biological monitoring shows that changes in water quality influence the diversity of benthic macroinvertebrate. This study prove that biological monitoring by utilizing benthic macroinvertebrate can also be used in determining water quality of urban type river. It is also produced result that more readily interprets as it reveal past event disturbance which sometimes missed by physical

  5. Linkages between nutrients and assemblages of macroinvertebrates and fish in wadeable streams: Implication to nutrient criteria development

    Science.gov (United States)

    Wang, L.; Robertson, D.M.; Garrison, P.J.

    2007-01-01

    We sampled 240 wadeable streams across Wisconsin for different forms of phosphorus and nitrogen, and assemblages of macroinvertebrates and fish to (1) examine how macroinvertebrate and fish measures correlated with the nutrients; (2) quantify relationships between key biological measures and nutrient forms to identify potential threshold levels of nutrients to support nutrient criteria development; and (3) evaluate the importance of nutrients in influencing biological assemblages relative to other physicochemical factors at different spatial scales. Twenty-three of the 35 fish and 18 of the 26 macroinvertebrate measures significantly correlated (P macroinvertebrate measures that most strongly correlated with the most nutrient measures. Selected biological measures showed clear trends toward degradation as concentrations of phosphorus and nitrogen increased, and some measures showed clear thresholds where biological measures changed drastically with small changes in nutrient concentrations. Our selected environmental factors explained 54% of the variation in the fish assemblages. Of this explained variance, 46% was attributed to catchment and instream habitat, 15% to nutrients, 3% to other water quality measures, and 36% to the interactions among all the environmental variables. Selected environmental factors explained 53% of the variation in macroinvertebrate assemblages. Of this explained variance, 42% was attributed to catchment and instream habitat, 22% to nutrients, 5% to other water quality measures, and 32% to the interactions among all the environmental variables. ?? 2006 Springer Science+Business Media, Inc.

  6. Effects of highway construction on sediment and benthic macroinvertebrates in two tributaries of the lost river, West Virginia

    Science.gov (United States)

    Hedrick, Lara B.; Welsh, S.A.; Anderson, James T.

    2007-01-01

    During a three-year study of two tributaries being crossed by a four-lane highway under construction in the eastern panhandle of West Virginia, we found little difference in the amount of fine sediment collected at upstream and downstream sites. The downstream site on one tributary collected significantly greater amounts of sediment in 2003, prior to installation of sediment fencing. Despite several episodic flow events that caused changes in the streambed, benthic macroinvertebrate metrics did not differ significantly annually or seasonally between sites or between streams. On-site controls effectively checked new sedimentation, and benthic macroinvertebrates were not significantly impacted.

  7. The isolation and characterization of actinobacteria from dominant benthic macroinvertebrates endemic to Lake Baikal.

    Science.gov (United States)

    Axenov-Gribanov, Denis; Rebets, Yuriy; Tokovenko, Bogdan; Voytsekhovskaya, Irina; Timofeyev, Maxim; Luzhetskyy, Andriy

    2016-03-01

    The high demand for new antibacterials fosters the isolation of new biologically active compounds producing actinobacteria. Here, we report the isolation and initial characterization of cultured actinobacteria from dominant benthic organisms' communities of Lake Baikal. Twenty-five distinct strains were obtained from 5 species of Baikal endemic macroinvertebrates of amphipods, freshwater sponges, turbellaria worms, and insects (caddisfly larvae). The 16S ribosomal RNA (rRNA)-based phylogenic analysis of obtained strains showed their affiliation to Streptomyces, Nocardia, Pseudonocardia, Micromonospora, Aeromicrobium, and Agromyces genera, revealing the diversity of actinobacteria associated with the benthic organisms of Lake Baikal. The biological activity assays showed that 24 out of 25 strains are producing compounds active against at least one of the test cultures used, including Gram-negative bacteria and Candida albicans. Complete dereplication of secondary metabolite profiles of two isolated strains led to identification of only few known compounds, while the majority of detected metabolites are not listed in existing antibiotic databases. PMID:26347255

  8. Benthic macroinvertebrates as bioindicators of water quality in an Atlantic forest fragment

    Directory of Open Access Journals (Sweden)

    Augusto Oliveira

    2010-12-01

    Full Text Available The objective of this study was to evaluate benthic macroinvertebrate communities as bioindicators of water quality in five streams located in the "Reserva Particular do Patrimônio Natural" (RPPN Mata Samuel de Paula and its surroundings, in the municipality of Nova Lima near the city of Belo Horizonte, Minas Gerais State, southeastern Brazil. This region has been strongly modified by human activities including mining and urbanization. Samples were collected in the field every three months between August 2004 and November 2005, totaling six samplings in the rainy and dry seasons. This assessment identified one area ecologically altered while the other sampling sites were found to be minimally disturbed systems, with well-preserved ecological conditions. However, according to the Biological Monitoring Work Party (BMWP and the Average Score Per Taxon (ASPT indices, all sampling sites had excellent water quality. A total of 14,952 organisms was collected, belonging to 155 taxa (148 Insecta, two Annelida, one Bivalvia, one Decapoda, one Planariidae, one Hydracarina, and one Entognatha. The most abundant benthic groups were Chironomidae (47.9%, Simuliidae (12.3%, Bivalvia (7.5%, Decapoda (6.1%, Oligochaeta (5.2%, Polycentropodidae (3.7%, Hydropsychidae (2.5%, Calamoceratidae (1.8%, Ceratopogonidae (1.7%, and Libellulidae (1.2%. The assessment of the benthic functional feeding groups showed that 34% of the macroinvertebrates were collector-gatherers, 29% predators, 24% collector-filterers, 8% shredders, and 5% scrapers. The RPPN Mata Samuel de Paula comprises diversified freshwater habitats that are of great importance for the conservation of many benthic taxa that are intolerant to organic pollution.

  9. The role of the hydrological cycle on the temporal patterns of macroinvertebrate assemblages in an Andean foothill stream in Colombia

    Directory of Open Access Journals (Sweden)

    María I. Ríos-Pulgarín

    2016-03-01

    Full Text Available The seasonal and interannual changes in the structure, composition and functional feeding groups of the macroinvertebrate assemblage of the Guarinó River, a torrential system located in the Colombian Andean foothills, were examined in relation to the physical and chemical environmental changes associated with the hydrological cycle and the El Niño-Niña/Southern Oscillation (ENSO between 2007 and 2010. Benthic samples were collected at three sites in the lower sections of the river. A total of 127 taxa were collected in the study, with the total taxonomic richness per site ranging from 82 to 96 taxa and benthos density averaging 5.41 ind. m-2. The density showed a tendency to decrease in periods of maximum river level and flow, particularly during La Niña phenomena, and to increase in dry periods, especially in the third year (2009-2010 during El Niño phenomena. The presence and abundance of taxa, functional feeding groups and life habits were regulated by environmental parameters associated with hydrological variability, derived of ENSO phenomena, especially flow rate values. The assemblage showed high taxonomic and functional diversity, which is characteristic of ecosystems affected by recurrent hydrological disturbances, exhibiting differentiated responses based on adaptive strategies against the local hydrologic regime that allow fast recovery under conditions like ENSO phenomena. Such responses include composition changes according to adaptations to different hydrological scenarios, the predominance of generalist trophic guilds and taxa with plasticity in their habits and range of environmental tolerance.

  10. Permafrost thaw and intense thermokarst activity decreases abundance of stream benthic macroinvertebrates.

    Science.gov (United States)

    Chin, Krista S; Lento, Jennifer; Culp, Joseph M; Lacelle, Denis; Kokelj, Steven V

    2016-08-01

    Intensification of permafrost thaw has increased the frequency and magnitude of large permafrost slope disturbances (mega slumps) in glaciated terrain of northwestern Canada. Individual thermokarst disturbances up to 40 ha in area have made large volumes of previously frozen sediments available for leaching and transport to adjacent streams, significantly increasing sediment and solute loads in these systems. To test the effects of this climate-sensitive disturbance regime on the ecology of Arctic streams, we explored the relationship between physical and chemical variables and benthic macroinvertebrate communities in disturbed and undisturbed stream reaches in the Peel Plateau, Northwest Territories, Canada. Highly disturbed and undisturbed stream reaches differed with respect to taxonomic composition and invertebrate abundance. Minimally disturbed reaches were not differentiated by these variables but rather were distributed along a disturbance gradient between highly disturbed and undisturbed sites. In particular, there was evidence of a strong negative relationship between macroinvertebrate abundance and total suspended solids, and a positive relationship between abundance and the distance from the disturbance. Increases in both sediments and nutrients appear to be the proximate cause of community differences in highly disturbed streams. Declines in macroinvertebrate abundance in response to slump activity have implications for the food webs of these systems, potentially leading to negative impacts on higher trophic levels, such as fish. Furthermore, the disturbance impacts on stream health can be expected to intensify as climate change increases the frequency and magnitude of thermokarst. PMID:26766394

  11. Influence of benthic macro-invertebrate bioturbation on the biogeochemical behaviour of uranium within freshwater sediments

    International Nuclear Information System (INIS)

    In freshwater ecosystems, sediments act as an accumulation compartment for metallic pollutants as uranium. Secondary, there can also represent endogenous sources of contamination by resuspension (e.g. flood, bioturbation) or changes of metal speciation that acts upon their bioavailability. Indeed, metallic compounds can be transformed in more or less toxic or inert compounds through physico-chemical (e.g. pH, redox conditions, ionic force) and microbiological variations. These conditions are themselves under the effects of benthic macro-invertebrate activities via bioturbation processes. The main objective of this PhD was to determinate the influence of two benthic macro-invertebrate species (Chironomus riparius and Tubifex tubifex) on the distribution and the transfers of uranium within freshwater sediments. To reach this goal, laboratory experiments were performed in order to (i) assess the effects of uranium on benthic macro-invertebrates, more particularly on their bioturbation activity, (ii) determine the influence of these organisms on uranium behaviour through high resolution physico-chemical measurements (e.g. oxygen optodes, DET gel probes), and (iii) estimate the consequences of these interactions on pelagic organisms via genotoxicity measurements (micronuclei assay and molecular bio-markers analysis on Xenopus laevis). The results demonstrate that bioturbation intensity of macro-invertebrates can be affected in uranium-contaminated sediments, but the two species studied in this work show a relative tolerance. For high uranium concentrations (>100 times the geochemical background level), corresponding however to realistic concentrations in highly contaminated sites, T. tubifex worms are able to maintain a sufficient bioturbation activity that induces a high remobilization of uranium initially associated with sediments to the overlying water (factor 2 to 10). That represents therefore a potential risk for the remaining aquatic biocenose. However, by

  12. Analytical approaches used in stream benthic macroinvertebrate biomonitoring programs of State agencies in the United States

    Science.gov (United States)

    Carter, James L.; Resh, Vincent H.

    2013-01-01

    Biomonitoring programs based on benthic macroinvertebrates are well-established worldwide. Their value, however, depends on the appropriateness of the analytical techniques used. All United States State, benthic macroinvertebrate biomonitoring programs were surveyed regarding the purposes of their programs, quality-assurance and quality-control procedures used, habitat and water-chemistry data collected, treatment of macroinvertebrate data prior to analysis, statistical methods used, and data-storage considerations. State regulatory mandates (59 percent of programs), biotic index development (17 percent), and Federal requirements (15 percent) were the most frequently reported purposes of State programs, with the specific tasks of satisfying the requirements for 305b/303d reports (89 percent), establishment and monitoring of total maximum daily loads, and developing biocriteria being the purposes most often mentioned. Most states establish reference sites (81 percent), but classify them using State-specific methods. The most often used technique for determining the appropriateness of a reference site was Best Professional Judgment (86 percent of these states). Macroinvertebrate samples are almost always collected by using a D-frame net, and duplicate samples are collected from approximately 10 percent of sites for quality assurance and quality control purposes. Most programs have macroinvertebrate samples processed by contractors (53 percent) and have identifications confirmed by a second taxonomist (85 percent). All States collect habitat data, with most using the Rapid Bioassessment Protocol visual-assessment approach, which requires ~1 h/site. Dissolved oxygen, pH, and conductivity are measured in more than 90 percent of programs. Wide variation exists in which taxa are excluded from analyses and the level of taxonomic resolution used. Species traits, such as functional feeding groups, are commonly used (96 percent), as are tolerance values for organic pollution

  13. Assessment of benthic macroinvertebrates at Nile tilapia production using artificial substrate samplers.

    Science.gov (United States)

    Moura E Silva, M S G; Graciano, T S; Losekann, M E; Luiz, A J B

    2016-05-17

    Biomonitoring is a cheap and effective tool for evaluation of water quality, and infer on the balance of aquatic ecosystems. The benthic macroinvertebrates are bioindicators sensitive to environmental changes, and can assist in detecting and preventing impacts such as organic enrichment and imbalance in the food chain. We compared the structure of benthic communities on artificial substrate samplers located in places near and far from net cages for production of Nile tilapia (Oreochromis niloticus). Samplers were manufactured with nylon net, using substrates such as crushed stone, gravel, loofah and cattail leaves. Samples were collected after 30 days of colonization, rinsed and then the specimens were identified and quantified. The following metrics were calculated: richness of Operational Taxonomic Units, Margalef richness, abundance of individuals, Shannon index and evenness index. The macrobenthic community structure was strongly modified according to the proximity of the net cages. Metrics showed significant differences (p macroinvertebrate community, as near sites showed higher values for the community metrics, such as richness and diversity. Near sites presented a larger number of individuals, observed both in the dry and rainy seasons, with a predominance of Chironomidae (Diptera) in the dry season and Tubificidae (Oligochaeta) in the rainy season. PMID:27191461

  14. Benthic macroinvertebrates in lake ecological assessment: A review of methods, intercalibration and practical recommendations.

    Science.gov (United States)

    Poikane, Sandra; Johnson, Richard K; Sandin, Leonard; Schartau, Ann Kristin; Solimini, Angelo G; Urbanič, Gorazd; Arbačiauskas, Kęstutis; Aroviita, Jukka; Gabriels, Wim; Miler, Oliver; Pusch, Martin T; Timm, Henn; Böhmer, Jürgen

    2016-02-01

    Legislation in Europe has been adopted to determine and improve the ecological integrity of inland and coastal waters. Assessment is based on four biotic groups, including benthic macroinvertebrate communities. For lakes, benthic invertebrates have been recognized as one of the most difficult organism groups to use in ecological assessment, and hitherto their use in ecological assessment has been limited. In this study, we review and intercalibrate 13 benthic invertebrate-based tools across Europe. These assessment tools address different human impacts: acidification (3 methods), eutrophication (3 methods), morphological alterations (2 methods), and a combination of the last two (5 methods). For intercalibration, the methods were grouped into four intercalibration groups, according to the habitat sampled and putative pressure. Boundaries of the 'good ecological status' were compared and harmonized using direct or indirect comparison approaches. To enable indirect comparison of the methods, three common pressure indices and two common biological multimetric indices were developed for larger geographical areas. Additionally, we identified the best-performing methods based on their responsiveness to different human impacts. Based on these experiences, we provide practical recommendations for the development and harmonization of benthic invertebrate assessment methods in lakes and similar habitats. PMID:26580734

  15. SPATIO-TEMPORAL VARIATIONS IN MACROINVERTEBRATE ASSEMBLAGES OF NEW CALEDONIAN STREAMS.

    Directory of Open Access Journals (Sweden)

    MARY N. J.

    2002-01-01

    Full Text Available Forty-one sites located on 14 New Caledonian streams were surveyed four times between October 1996 and October 1997 in order to examine the spatial and temporal changes in the structure of the benthic macroinvertebrate communities. About 250 000 invertebrates representing 167 taxa were collected in the streams. Seventy-five percent of identified taxa and 67% of individuals were insects. Major spatial and temporal changes in the composition of the fauna were detected by multivariate analyses (ordination and classification. Overall, the number of individuals was significantly higher in the dry season (October than in the wetter seasons (January and June. However, a low temporal variability was detected in the structure of benthic communities during the sampling period. A cluster analysis based on taxonomic composition separated five groups of sites in relation with rock type, land use, and geographic characteristics. Several metrics (total invertebrate density, taxon richness, relative abundance of major invertebrate groups, diversity indices were used to characterize each group of sites. Forested streams, where the highest specific diversity occurred, represented the most speciose habitat for benthic fauna. A less rich and abundant fauna occurred in streams draining ultramafic rocks probably because of their low content in food resources and organic matter.

  16. Application of Water Quality and Ecology Indices of Benthic Macroinvertebrate to Evaluate Water Quality of Tertiary Irrigation in Malang District

    Directory of Open Access Journals (Sweden)

    Desi Kartikasari

    2013-12-01

    Full Text Available This research aims to determine the water quality of tertiary irrigation in several subdistricts in Malang, namely Kepanjen, Karangploso, and Tumpang. The water quality depends on the water quality indices (National Sanitation Foundation’s-NSF Indices and O’Connor’s Indices based on variables TSS, TDS, pH, DO, and Nitrate concentrate and ecological indices of benthic macroinvertebrate (Diversity Indices Shannon-Wiener, Hilsenhof Biotic Indices-HBI, Average Score per Taxon-ASPT which is calculated by Biological Monitoring Working Party-BMWP, Ephemeroptera Indices, Plecoptera, Trichoptera-EPT. Observation of the physico-chemical water quality and benthic macroinvertebrate on May 2012 to April 2013. The sampling in each subdistrict was done at two selected stations in tertiary irrigation channel with three plot at each station. The data of physico-chemical quality of water were used to calculate the water quality indices, while the benthic macroinvertebrate data were used to calculate the ecological indices. The research findings showed that 27 taxa of benthic macroinvertebrates belong 10 classes were found in the three subdistrict. The pH, DO, Nitrate, TSS and TDS in six tertiary irrigation channels in Malang still met the water quality standards based on Government Regulation No. 82 of 2001 on Management of Water Quality and Water Pollution Control Class III. Based on NSF-WQI indices and O'Connor's Indices, water qualities in these irrigation channels were categorized into medium or moderate (yellow to good (green category. However, based on benthic macroinvertebrate communities which was used to determine the HBI, the water quality in the irrigation channels were categorized into the fair category (fairly significant organic pollution to fairly poor (significant organic pollution, while based on the value of ASPT, the water were categorized into probable moderate pollution to probable severe pollution. The irrigation water which was

  17. Long-Term Benthic Macroinvertebrate Community Monitoring to Assess Pollution Abatement Effectiveness

    Energy Technology Data Exchange (ETDEWEB)

    Smith, John G [ORNL; Brandt, Craig C [ORNL; Christensen, Sigurd W [ORNL

    2011-01-01

    The benthic macroinvertebrate community of East Fork Poplar Creek (EFPC) in East Tennessee was monitored for 18 years to evaluate the effectiveness of a water pollution control program implemented at a major United States (U.S.) Department of Energy facility. Several actions were implemented to reduce and control releases of pollutants into the headwaters of the stream. Four of the most significant actions were implemented during different time periods, which allowed assessment of each action. Macroinvertebrate samples were collected annually in April from three locations in EFPC (EFK24, EFK23, and EFK14) and two nearby reference streams from 1986 through 2003. Significant improvements occurred in the macroinvertebrate community at the headwater sites (EFK24 and EFK23) after implementation of each action, while changes detected 9 km further downstream (EFK14) could not be clearly attributed to any of the actions. Because the stream was impacted at its origin, invertebrate recolonization was primarily limited to aerial immigration, thus, recovery has been slow. As recovery progressed, abundances of small pollution-tolerant taxa (e.g., Orthocladiinae chironomids) decreased and longer lived taxa colonized (e.g., hydropsychid caddisflies, riffle beetles, Baetis). While assessments lasting three to four years may be long enough to detect a response to new pollution controls at highly impacted locations, more time may be needed to understand the full effects. Studies on the effectiveness of pollution controls can be improved if impacted and reference sites are selected to maximize spatial and temporal trending, and if a multidisciplinary approach is used to broadly assess environmental responses (e.g., water quality trends, invertebrate and fish community assessments, toxicity testing, etc.).

  18. Drivers of abundance and community composition of benthic macroinvertebrates in Ottawa River sediment near Chalk River Laboratories

    International Nuclear Information System (INIS)

    The Ottawa River has received effluent from Chalk River Laboratories (CRL) for more than 60 years. Some radionuclides and contaminants released in effluents are bound rapidly to particles and deposited in bottom sediments where they may be biologically available to benthic invertebrates and other aquatic biota. As part of a larger ecological assessment, we assess the potential impact of contaminated sediments in the vicinity of CRL on local benthic community structure. Using bivariate and multivariate approaches, we demonstrate that CRL operations have had little impact on the local benthic community. Despite elevated anthropogenic radionuclide activity concentrations in sediment near CRL's process outfall, the benthic community is no less abundant or diverse than what is observed upstream at background levels. The Ottawa River benthic invertebrate community is structured predominantly by natural physical and biological conditions in the sediment, specifically sediment water content and organic content. These natural habitat conditions have a stronger influence on macroinvertebrate communities than sediment contamination. (author)

  19. Drivers of abundance and community composition of benthic macroinvertebrates in Ottawa River sediment near Chalk River Laboratories

    Energy Technology Data Exchange (ETDEWEB)

    Bond, M.J.; Rowan, D.; Silke, R.; Carr, J., E-mail: bondm@aecl.ca [Atomic Energy of Canada Limited, Chalk River, Ontario (Canada)

    2013-12-15

    The Ottawa River has received effluent from Chalk River Laboratories (CRL) for more than 60 years. Some radionuclides and contaminants released in effluents are bound rapidly to particles and deposited in bottom sediments where they may be biologically available to benthic invertebrates and other aquatic biota. As part of a larger ecological assessment, we assess the potential impact of contaminated sediments in the vicinity of CRL on local benthic community structure. Using bivariate and multivariate approaches, we demonstrate that CRL operations have had little impact on the local benthic community. Despite elevated anthropogenic radionuclide activity concentrations in sediment near CRL's process outfall, the benthic community is no less abundant or diverse than what is observed upstream at background levels. The Ottawa River benthic invertebrate community is structured predominantly by natural physical and biological conditions in the sediment, specifically sediment water content and organic content. These natural habitat conditions have a stronger influence on macroinvertebrate communities than sediment contamination. (author)

  20. Rapid integrated water quality evaluation of Mahisagar river using benthic macroinvertebrates.

    Science.gov (United States)

    Bhadrecha, M H; Khatri, Nitasha; Tyagi, Sanjiv

    2016-03-01

    The water quality of Mahisagar river, near Galteshwar in Kheda district of Gujarat, India, was assessed through a rapid integrated technique by physicochemical parameters as well as benthic macroinvertebrates. Physicochemical parameters retrieved were pH, color, conductivity, total solids, total suspended solids, total dissolved solids, chlorides, total hardness, calcium hardness, magnesium hardness, alkalinity, turbidity, ammoniacal nitrogen, chemical oxygen demand, biochemical oxygen demand, dissolved oxygen, sulfates, and nitrates. The biological indices calculated were BMWP (Bio Monitoring Working Party) score or saprobic score and sequential comparison index or diversity score. In total, 37 families were encountered along the studied river stretch. The findings indicate that the water quality of Mahisagar river at sampled locations is "slightly polluted." Moreover, the results of physicochemical analysis are also in consonance with the biological water quality criteria developed by Central Pollution Control Board. PMID:27025593

  1. The use and limits of various methods of sampling and interpretation of benthic macro-invertebrates

    Directory of Open Access Journals (Sweden)

    Antony DAVIES

    2001-09-01

    Full Text Available This paper attempts to provide an overview of the present state of the art of biological sampling of aquatic benthic macro-invertebrates as reflected in the international standard methods of the International Standards Organisation (ISO and the European Standards Organisation (CEN. Also of importance are guideline standards which assist in the standardisation of the interpretation and presentation of the biological data. The importance of standardising methods of sampling aquatic habitats has been recently recognised by the European Union by the inclusion of these standards as a mandatory requirement within the Framework Directive (2000/60 EC European Parliament and Council for the protection of inland surface waters. Adherence to these standards of sampling by member countries ensures that the biological survey data is comparable throughout the Union and can be assessed as an improvement, deterioration or stable biological quality at agreed survey sites.

  2. Rapid integrated water quality evaluation of Mahisagar river using benthic macroinvertebrates.

    Science.gov (United States)

    Bhadrecha, M H; Khatri, Nitasha; Tyagi, Sanjiv

    2016-04-01

    The water quality of Mahisagar river, near Galteshwar in Kheda district of Gujarat, India, was assessed through a rapid integrated technique by physicochemical parameters as well as benthic macroinvertebrates. Physicochemical parameters retrieved were pH, color, conductivity, total solids, total suspended solids, total dissolved solids, chlorides, total hardness, calcium hardness, magnesium hardness, alkalinity, turbidity, ammoniacal nitrogen, chemical oxygen demand, biochemical oxygen demand, dissolved oxygen, sulfates, and nitrates. The biological indices calculated were BMWP (Bio Monitoring Working Party) score or saprobic score and sequential comparison index or diversity score. In total, 37 families were encountered along the studied river stretch. The findings indicate that the water quality of Mahisagar river at sampled locations is “slightly polluted.” Moreover, the results of physicochemical analysis are also in consonance with the biological water quality criteria developed by Central Pollution Control Board. PMID:27358997

  3. Stream health of Courtland Creek, Oakland, California utilizing benthic macroinvertebrates as ecological indicators

    Science.gov (United States)

    White, K.; Ahumada, A.; Lopez, C.; Phillips, A.; Varella, N.; Torres, E.; Quintero, D.; Bracho, H.

    2012-12-01

    An initial benthic macroinvertebrate and water quality survey was conducted on Courtland Creek, Oakland, California. Samples were collected from 3 sites between Brookdale avenue and 45th street at accessible sections of this largely culverted stream. To collect macroinvertebrates, brass frame kick nets with 500 micron netting were placed in the stream and substrate was disturbed for 1 minute in front of the opening of the kick net. The kick net was rinsed into a tub and invertebrates were identified and sorted on site. Organisms were ranked using a biotic index and average index was determined for each site. The biotic index of each site ranked the stream overall as poor. Dissolved oxygen and Nitrates were measured using wet chemistry procedures. Dissolved oxygen levels in the stream are sufficient for invertebrates but low for a stream at 4-5ppm. Nitrate levels were significantly high concentrations of 40 ppm for all sites. Nitrate levels recorded could reflect the presence of animal waste in the water or agricultural fertilizer from private homes and gardens that adjoin the stream. The presence of animal waste was observed at all sites in the study area and may have caused the levels of nitrates observed. Nitrate levels are not at toxic levels but at this level affect immunological functions of invertebrates. Results indicate that the habitat and water quality of Courtland Creek is in poor condition and restoration is recommended in order to increase the ecological health or this urban watershed.

  4. Spatial and temporal heterogeneity in a subtropical reservoir and their effects over the benthic macroinvertebrate community

    Directory of Open Access Journals (Sweden)

    Frederico Guilherme de Souza Beghelli

    2014-09-01

    Full Text Available AIM: The objective of the present study was to demonstrate the influences of the environment spatial heterogeneity on benthic macroinvertebrates considering transverse and longitudinal gradients as also seasonality. METHODS: Four samplings were performed: two in the wet and two in the dry season in the riverine, transitional and lacustrine zones in the littoral and profundal regions of Itupararanga reservoir, SP, Brazil. Abiotic characterization of the water and of the sediment was performed. The biotic characterization was based on richness, dominance, diversity, and density of organisms, as well as on the relative abundance of predominant taxa. Two-way ANOSIM analyses were performed for both biotic and abiotic components, in order to test the significance of the differences in the longitudinal and transverse directions as well as of the differences between seasons. RESULTS: Compartmentalization was present in both directions, longitudinal and transverse. In a general way, the littoral region presented higher diversity values when compared with the profundal region, and the riverine zone presented high densities and high percentage of taxons, which usually indicate organic pollution. The differentiation between the transitional and lacustrine zones was determined mainly by taxonomic composition. Seasonality was also observed and the transportation of small particles, the entrance of nutrients, and the presence of macrophytes were considered as determinants for differentiation. CONCLUSIONS: Together, these results demonstrate the responses of benthic macroinvertebrate communities considering distinct sources of variation: longitudinal heterogeneity, determined by the increasing distance from the forming rivers that leads to a gradient of physical and chemical conditions; transverse heterogeneity, determined by the proximity with the land environment and depth differences. Seasonal heterogeneity was recorded during the period of this research and

  5. Tolerance of benthic macroinvertebrates to organic enrichment in highland streams of northeastern Rio Grande do Sul, Brazil

    Directory of Open Access Journals (Sweden)

    Aline Correa Mazzoni

    2014-06-01

    Full Text Available AIM: the aim of this study was to determine the ecological valence of benthic macroinvertebrates at different pollution levels in highland rivers and streams of Rio Grande do Sul; METHODS: the dataset proceeds from samplings performed between 2002-2011 in 35 lotic ecosystems. The Chemical Index was used to determine pollution levels. Indices of richness and Shannon diversity were applied to characterize the structure of benthic communities. The descriptors used to determine taxa's ecological valence were selected according to Coefficient of Variation and regression analyses. Groups of tolerance were identified using Interquartile range and cluster analysis; RESULTS: Conductivity and Chemical Index were the descriptors best related with diversity of benthic macroinvertebrate community. These metrics were used to determine the tolerance range of 38 taxa. Interquartile range and cluster analysis revealed three groups of taxa, according to their occurrence in different levels of pollution: taxa with narrow amplitudes, present at sites with very low or very high load of organic enrichment; taxa with moderate amplitude, found until moderately polluted sites; and taxa with occurrence in widespread environmental conditions. The results, when compared to other studies in Brazil, showed differences in some taxa's tolerance. This observation indicates the need to assess the bioindication potential of these taxa in genus and species level; CONCLUSION: the present study contributes to increase knowledge about the bioindicator potential of benthic macroinvertebrates. Therefore, the study supports an advanced biomonitoring of ecological quality in mountain streams of southern Brazil.

  6. Assessment of mercury bioavailability to benthic macroinvertebrates using diffusive gradients in thin films (DGT).

    Science.gov (United States)

    Amirbahman, Aria; Massey, Delia I; Lotufo, Guilherme; Steenhaut, Nicholas; Brown, Lauren E; Biedenbach, James M; Magar, Victor S

    2013-10-01

    Mercury-specific diffusive gradient in thin films (DGTs) were used in laboratory microcosms as a biomonitoring tool to assess the lability of mercury (Hg) total and monomethylmercury Hg (MeHg), and to develop a relationship between chemical lability and bioavailability in estuarine sediments. Time-series deployment of DGTs in sediments showed that sediment-bound MeHg is more labile than sediment-bound inorganic Hg. In subsequent experiments, DGTs were deployed simultaneously with three benthic macroinvertebrates (the estuarine amphipod, Leptocheirus plumulosus; the estuarine polychaete, Nereis virens; and the marine clam, Macoma nasuta) in sediments for up to 55 days. All organisms and their co-deployed DGTs exhibited an initial period of rapid Hg uptake followed by slower uptake reaching apparent steady state. Strong correlative relationships were generally observed between paddle-type DGTs and macroinvertebrate tissue data (r(2) between 0.57 and 0.97). Further, %MeHg:Total Hg ratios for M. nasuta and N. virens (38.5 ± 12.2 and 19.2 ± 5.2) were similar to their corresponding ratios for the DGTs (33.1 ± 13.3 and 24.4 ± 11.0), and they were significantly higher than the same ratios for sediment (2.9 ± 0.3) and pore water (8.5 ± 4.9). The %MeHg:Total Hg ratios for L. plumulosus (68.5 ± 6.2) were significantly higher than those for the DGTs. This may be because the tissue and DGT data for this organism were not truly co-located as L. plumulosus burrows close to the sediment surface, and the DGTs sampled the sediment surface. Overall, our results suggest that for benthic macroinvertebrates in estuarine sediments studied here, (a) sediment MeHg is more bioavailable than inorganic Hg, (b) sediment and pore-water concentration measurements are not good predictors for the extent of bioaccumulation of Hg species, and (c) DGTs are an effective biomonitoring tool for the assessment of bioavailability of Hg species. PMID:24084872

  7. Macroinvertebrate assemblages and biodiversity levels: ecological role of constructed wetlands and artificial ponds in a natural park

    Directory of Open Access Journals (Sweden)

    Laura Sartori

    2014-02-01

    Full Text Available Normal 0 14 false false false MicrosoftInternetExplorer4 Constructed wetlands play an important role in water supply, floodwater retention and nutrient removal, at the same time allowing the restoration of lost habitat and the preservation of biodiversity. There is little knowledge about the biodiversity that can be found in these artificial environments along time, especially at the invertebrate community level. Macroinvertebrate assemblages, water chemistry, morphology, and environmental characteristics of natural ponds, artificial pools and constructed wetlands in Parco Pineta (Northern Italy were studied to evaluate the effects of local factors on macroinvertebrate communities. The objective was to verify if each ecosystem could equally contribute to local biodiversity, regardless of its natural or artificial origin. Principal Components Analysis showed that ponds were divided into clusters, based on their morphology and their water quality, independently from their origin. The composition of macroinvertebrate communities was similar among natural wetlands and ponds artificially created to provide new habitats in the park, while it was different among natural wetlands and constructed wetlands created for wastewater treatment purposes. Biodiversity of natural ponds and constructed wetlands, evaluated using taxa richness, Shannon index, and Pielou index, was comparable. Canonical Correspondence Analysis highlighted differences in macroinvertebrate community composition and pointed out the relationships among macroinvertebrates and various environmental variables: habitat heterogeneity resulted as the most relevant factor that influences taxa richness. Water quality also affects the macroinvertebrate community structure. We determined that constructed wetlands with higher pollutant concentrations show different assemblage compositions but comparable overall macroinvertebrate biodiversity. Constructed wetlands became valuable ecological elements

  8. Effectiveness of Road-Stream Crossing Improvements and Bank Stabilization in the Manistee River Watershed, MI: Response of the Benthic Macroinvertebrates

    Science.gov (United States)

    Stout, N. Y.; Wright, A. L.; Gressick, N. J.; Snyder, E. B.

    2005-05-01

    The Manistee River Watershed is a unique resource used by many individuals including the Little River Band of Ottawa Indians (LRBOI). However, the presence of excessive sediment from continued erosion of stream banks and poorly designed road-stream crossings threaten habitat quality. The U.S. EPA has recently awarded a grant to the LRBOI to improve road-stream crossings and stabilize stream banks. Our objective is to determine how these improvements affect the physical habitat of the stream and the response of macroinvertebrate assemblages. Initial results from a subset of 10 sites indicate that immediately below a restoration site, there was a decline in abundance and family richness post-restoration. Likely this was due to construction-related deposition of sand, which particularly impacted the Diptera (Simuliidae spp. and Chironomidae spp.). In contrast, fall sampling of sites further from the construction zone exhibited an increase in benthic abundance (from 204 to 816 individuals/m2). The extent to which the construction-generated sand will have impacted reaches further from the restoration site are continuing to be monitored. Although the short-term effects appear to be negative, we believe the ongoing monitoring will document an eventual improvement in the macroinvertebrate community and in overall stream ecosystem integrity.

  9. Nestedness and successional trajectories of macroinvertebrate assemblages in man-made wetlands.

    Science.gov (United States)

    Ruhí, Albert; Boix, Dani; Gascón, Stéphanie; Sala, Jordi; Quintana, Xavier D

    2013-02-01

    Current successional models, primarily those based on floral succession, propose several distinct trajectories based on the integration of two key hypotheses from succession theory: convergence versus divergence in species composition among successional sites, and progression towards versus deviation from a desired reference state. We applied this framework to faunal succession, including differential colonization between active and passive dispersers, and the nested patterns generated as a consequence of this peculiarity. Nine man-made wetlands located in three different areas, from 0-3 years from wetland creation, were assessed. In addition, 91 wetlands distributed throughout the region were used as references for natural macroinvertebrate communities. We predicted the following: (1) highly nested structures in pioneering assemblages will decrease to lower mid-term values due to a shift from active pioneering taxa to passive disperser ones; (2) passive idiosyncratic taxa will elicit divergent successional trajectories among areas; (3) the divergent trajectories will provoke lower local and higher regional diversity values in the mid-term assemblages than in pioneer assemblages. Our results were largely congruent with hypotheses (1) and (2), diverging from the anticipated patterns only in the case of the temporary wetlands area. However, overall diversity trends based on hypothesis (3) did not follow the expected pattern. The divergent successional trajectories did not compensate for regional biodiversity losses that occurred as a consequence of pioneering colonizer decline over time. Consequently, we suggest reconsidering wetland construction for mitigation purposes within mid-term time frames (≤ 3 years). Wetlands may not offset, within this temporal scenario, regional biodiversity loss because the ecosystem may not support idiosyncratic taxa from natural wetlands. PMID:22965268

  10. Analysis of Benthic Macroinvertebrates in Relation to Environmental Variables of Lake Gala, a National Park of Turkey

    OpenAIRE

    Çamur-Elipek, Belgin; Arslan, Naime; KIRGIZ, Timur; ÖTERLER, Burak; GÜHER, Hüseyin; Özkan, Nurcan

    2010-01-01

    In order to determine the relationships between the dynamics of benthic macroinvertebrates (both species number and individual number) and environmental variables, sampling was made at four different stations at monthly intervals during a year between March 2004 and January 2005 of Lake Gala which is a part of an important wetland and a national park in European part of Turkey (Enez/Edirne). Altogether, a total of 49 zoobenthic taxa which were grouped as "Oligochaeta", "Chi...

  11. Application of Water Quality and Ecology Indices of Benthic Macroinvertebrate to Evaluate Water Quality of Tertiary Irrigation in Malang District

    OpenAIRE

    Desi Kartikasari; Catur Retnaningdyah; Endang Arisoesilaningsih

    2013-01-01

    This research aims to determine the water quality of tertiary irrigation in several subdistricts in Malang, namely Kepanjen, Karangploso, and Tumpang. The water quality depends on the water quality indices (National Sanitation Foundation’s-NSF Indices and O’Connor’s Indices based on variables TSS, TDS, pH, DO, and Nitrate concentrate) and ecological indices of benthic macroinvertebrate (Diversity Indices Shannon-Wiener, Hilsenhof Biotic Indices-HBI, Average Score per Taxon-ASPT which is calcu...

  12. CONCORDANCE OF TAXONOMIC COMPOSITION PATTERNS ACROSS MULTIPLE LAKE ASSEMBLAGES: EFFECTS OF SCALE, BODY SIZE, AND LAND USE

    Science.gov (United States)

    We assessed environmental gradients and the extent to which they induced concordant patterns of taxonomic composition among benthic macroinvertebrate, riparian bird, sedimentary diatom, fish, and pelagic zooplankton assemblages in 186 northeastern U.S.A. lakes. Human population ...

  13. Impact assessment of agricultural driven stressors on benthic macroinvertebrates using simulated data.

    Science.gov (United States)

    Stefanidis, K; Panagopoulos, Y; Mimikou, M

    2016-01-01

    Agricultural land use poses a significant threat to the ecological integrity of rivers in Europe. Particularly in the Mediterranean, water abstraction and nutrient application are anthropogenic pressures that have a significant impact on aquatic habitats and biodiversity. In this article, we assessed the effects of agricultural management practices on benthic macroinvertebrates in a large river basin of central Greece using simulated data based on the application of SWAT (Soil Water Assessment Tool) model. Physicochemical and hydrological output variables of the model were used as predictors of the ASPT (Average Score Per Taxon) metric based on a correlated component regression analysis (CCR) built on empirical data. The estimation of ASPT was performed for the wet and dry seasons within a 20-year period for a total of 47 subbasins under the baseline conditions and after implementing three management scenarios that reduced: a) irrigation water applied to crops by 30%, b) chemical fertilization applied to crops by 30% and c) both irrigation and fertilization by 30%. The results revealed that application of the reduced irrigation resulted to a slight increase of the simulated dissolved inorganic nitrogen concentration (DIN), which in turn decreased the mean ASPT in 21 of the 47 subbasins implying a negative effect on the macroinvertebrate communities. On the contrary, the reduction of fertilization as well as the combined scenario decreased both the simulated DIN and phosphate concentration causing an increase of the mean ASPT for a total of 40 of the 47 subbasins. Based on these results, we suggest that the best management option is a combined practice of deficit irrigation and fertilization reduction since it improved water quality, increased ASPT values and saved a considerable amount of water. Overall, this work demonstrates a simple methodology that can efficiently assess the effects of agricultural management practices on biotic indicators. PMID:26311349

  14. An evaluation of the relative quality of dike pools for benthic macroinvertebrates in the Lower Missouri River, USA

    Science.gov (United States)

    Poulton, B.C.; Allert, A.L.

    2012-01-01

    A habitat-based aquatic macroinvertebrate study was initiated in the Lower Missouri River to evaluate relative quality and biological condition of dike pool habitats. Water-quality and sediment-quality parameters and macroinvertebrate assemblage structure were measured from depositional substrates at 18 sites. Sediment porewater was analysed for ammonia, sulphide, pH and oxidation-reduction potential. Whole sediments were analysed for particle-size distribution, organic carbon and contaminants. Field water-quality parameters were measured at subsurface and at the sediment-water interface. Pool area adjacent and downstream from each dike was estimated from aerial photography. Macroinvertebrate biotic condition scores were determined by integrating the following indicator response metrics: % of Ephemeroptera (mayflies), % of Oligochaeta worms, Shannon Diversity Index and total taxa richness. Regression models were developed for predicting macroinvertebrate scores based on individual water-quality and sediment-quality variables and a water/sediment-quality score that integrated all variables. Macroinvertebrate scores generated significant determination coefficients with dike pool area (R2=0.56), oxidation–reduction potential (R2=0.81) and water/sediment-quality score (R2=0.71). Dissolved oxygen saturation, oxidation-reduction potential and total ammonia in sediment porewater were most important in explaining variation in macroinvertebrate scores. The best two-variable regression models included dike pool size + the water/sediment-quality score (R2=0.84) and dike pool size + oxidation-reduction potential (R2=0.93). Results indicate that dike pool size and chemistry of sediments and overlying water can be used to evaluate dike pool quality and identify environmental conditions necessary for optimizing diversity and productivity of important aquatic macroinvertebrates. A combination of these variables could be utilized for measuring the success of habitat enhancement

  15. Predicting ecological changes on benthic estuarine assemblages through decadal climate trends along Brazilian Marine Ecoregions

    Science.gov (United States)

    Bernardino, Angelo F.; Netto, Sérgio A.; Pagliosa, Paulo R.; Barros, Francisco; Christofoletti, Ronaldo A.; Rosa Filho, José S.; Colling, André; Lana, Paulo C.

    2015-12-01

    Estuaries are threatened coastal ecosystems that support relevant ecological functions worldwide. The predicted global climate changes demand actions to understand, anticipate and avoid further damage to estuarine habitats. In this study we reviewed data on polychaete assemblages, as a surrogate for overall benthic communities, from 51 estuaries along five Marine Ecoregions of Brazil (Amazonia, NE Brazil, E Brazil, SE Brazil and Rio Grande). We critically evaluated the adaptive capacity and ultimately the resilience to decadal changes in temperature and rainfall of the polychaete assemblages. As a support for theoretical predictions on changes linked to global warming we compared the variability of benthic assemblages across the ecoregions with a 40-year time series of temperature and rainfall data. We found a significant upward trend in temperature during the last four decades at all marine ecoregions of Brazil, while rainfall increase was restricted to the SE Brazil ecoregion. Benthic assemblages and climate trends varied significantly among and within ecoregions. The high variability in climate patterns in estuaries within the same ecoregion may lead to correspondingly high levels of noise on the expected responses of benthic fauna. Nonetheless, we expect changes in community structure and productivity of benthic species at marine ecoregions under increasing influence of higher temperatures, extreme events and pollution.

  16. A Multimetric Benthic Macroinvertebrate Index for the Assessment of Stream Biotic Integrity in Korea

    Directory of Open Access Journals (Sweden)

    Soon-Jin Hwang

    2012-10-01

    Full Text Available At a time when anthropogenic activities are increasingly disturbing the overall ecological integrity of freshwater ecosystems, monitoring of biological communities is central to assessing the health and function of streams. This study aimed to use a large nation-wide database to develop a multimetric index (the Korean Benthic macroinvertebrate Index of Biological Integrity—KB-IBI applicable to the biological assessment of Korean streams. Reference and impaired conditions were determined based on watershed, chemical and physical criteria. Eight of an initial 34 candidate metrics were selected using a stepwise procedure that evaluated metric variability, redundancy, sensitivity and responsiveness to environmental gradients. The selected metrics were number of taxa, percent Ephemeroptera-Plecoptera-Trichoptera (EPT individuals, percent of a dominant taxon, percent taxa abundance without Chironomidae, Shannon’s diversity index, percent gatherer individuals, ratio of filterers and scrapers, and the Korean saprobic index. Our multimetric index successfully distinguished reference from impaired conditions. A scoring system was established for each core metric using its quartile range and response to anthropogenic disturbances. The multimetric index was classified by aggregating the individual metric ..scores and the value range was quadrisected to provide a narrative criterion (Poor, Fair, Good and Excellent to describe the biological integrity of the streams in the study. A validation procedure showed that the index is an effective method for evaluating stream conditions, and thus is appropriate for use in future studies measuring the long-term status of streams, and the effectiveness of restoration methods.

  17. Inferring community properties of benthic macroinvertebrates in streams using Shannon index and exergy

    Science.gov (United States)

    Nguyen, Tuyen Van; Cho, Woon-Seok; Kim, Hungsoo; Jung, Il Hyo; Kim, YongKuk; Chon, Tae-Soo

    2014-03-01

    Definition of ecological integrity based on community analysis has long been a critical issue in risk assessment for sustainable ecosystem management. In this work, two indices (i.e., Shannon index and exergy) were selected for the analysis of community properties of benthic macroinvertebrate community in streams in Korea. For this purpose, the means and variances of both indices were analyzed. The results found an extra scope of structural and functional properties in communities in response to environmental variabilities and anthropogenic disturbances. The combination of these two parameters (four indices) was feasible in identification of disturbance agents (e.g., industrial pollution or organic pollution) and specifying states of communities. The four-aforementioned parameters (means and variances of Shannon index and exergy) were further used as input data in a self-organizing map for the characterization of water quality. Our results suggested that Shannon index and exergy in combination could be utilized as a suitable reference system and would be an efficient tool for assessment of the health of aquatic ecosystems exposed to environmental disturbances.

  18. Selecting a distributional assumption for modelling relative densities of benthic macroinvertebrates

    Science.gov (United States)

    Gray, B.R.

    2005-01-01

    ). However, the zero-modified Poisson models underestimated small counts (1 ??? y ??? 4) and overestimated intermediate counts (7 ??? y ??? 23). Counts greater than zero were estimated well by zero-modified negative binomial models, while counts greater than one were also estimated well by the standard negative binomial model. Based on AIC and percent zero estimation criteria, the two-stage and zero-inflated models performed similarly. The above inferences were largely confirmed when the models were used to predict values from a separate, evaluation data set (n = 110). An exception was that, using the evaluation data set, the standard negative binomial model appeared superior to its zero-modified counterparts using the AIC (but not percent zero criteria). This and other evidence suggest that a negative binomial distributional assumption should be routinely considered when modelling benthic macroinvertebrate data from low flow environments. Whether negative binomial models should themselves be routinely examined for extra zeroes requires, from a statistical perspective, more investigation. However, this question may best be answered by ecological arguments that may be specific to the sampled species and locations. ?? 2004 Elsevier B.V. All rights reserved.

  19. Effects of organic pollution and physical stress on benthic macroinvertebrate communities from two intermittently closed and open coastal lagoons (ICOLLs)

    Science.gov (United States)

    Coelho, Susana; Pérez-Ruzafa, Angel; Gamito, Sofia

    2015-12-01

    Benthic macroinvertebrate communities and environmental conditions were studied in two intermittently closed and open coastal lakes and lagoons (ICOLLs), located in southern Algarve (Foz do Almargem e Salgados), with the purpose of evaluating the effects of organic pollution, originated mainly from wastewater discharges, and the physical stress caused by the irregular opening of the lagoons. Most of the year, lagoons were isolated from the sea, receiving the freshwater inputs from small rivers and in Salgados, also from the effluents of a wastewater plant. According to environmental and biotic conditions, Foz do Almargem presented a greater marine influence and a lower trophic state (mesotrophic) than Salgados (hypereutrophic). Benthic macroinvertebrate communities in the lagoons were distinct, just as their relations with environmental parameters. Mollusca were the most abundant macroinvertebrates in Foz do Almargem, while Insecta, Oligochaeta and Crustacea were more relevant in Salgados. Corophium multisetosum occurred exclusively in Salgados stations and, just as Chironomus sp., other Insecta and Oligochaeta, densities were positively related to total phosphorus, clay content and chlorophyll a concentration in the sediment, chlorophyll a concentration in water and with total dissolved inorganic nitrogen. Abra segmentum, Cerastoderma glaucum, Peringia ulvae and Ecrobia ventrosa occurred only in Foz do Almargem, with lower values of the above mentioned parameters. Both lagoons were dominated by deposit feeders and taxa tolerant to environmental stress, although in Salgados there was a greater occurrence of opportunistic taxa associated to pronounced unbalanced situations, due to excess organic matter enrichment.

  20. Biological Assessment of Aquaculture Effects on Effluent-Receiving Streams in Ghana Using Structural and Functional Composition of Fish and Macroinvertebrate Assemblages

    Science.gov (United States)

    Ansah, Yaw Boamah; Frimpong, Emmanuel A.; Amisah, Stephen

    2012-07-01

    Biological assessment of aquatic ecosystems is widely employed as an alternative or complement to chemical and toxicity testing due to numerous advantages of using biota to determine ecosystem condition. These advantages, especially to developing countries, include the relatively low cost and technical requirements. This study was conducted to determine the biological impacts of aquaculture operations on effluent-receiving streams in the Ashanti Region of Ghana. We collected water, fish and benthic macroinvertebrate samples from 12 aquaculture effluent-receiving streams upstream and downstream of fish farms and 12 reference streams between May and August of 2009, and then calculated structural and functional metrics for biotic assemblages. Fish species with non-guarding mode of reproduction were more abundant in reference streams than downstream ( P = 0.0214) and upstream ( P = 0.0251), and sand-detritus spawning fish were less predominant in reference stream than upstream ( P = 0.0222) and marginally less in downstream locations ( P = 0.0539). A possible subsidy-stress response of macroinvertebrate family richness and abundance was also observed, with nutrient (nitrogen) augmentation from aquaculture and other farming activities likely. Generally, there were no, or only marginal differences among locations downstream and upstream of fish farms and in reference streams in terms of several other biotic metrics considered. Therefore, the scale of impact in the future will depend not only on the management of nutrient augmentation from pond effluents, but also on the consideration of nutrient discharges from other industries like fruit and vegetable farming within the study area.

  1. Epigeus macroinvertebrates species assemblages along a successional gradient in Hailuotu Island (Bothnia Bay, Finland

    Directory of Open Access Journals (Sweden)

    Adolfo A. Del Rio Mora

    2014-03-01

    Full Text Available Epigeus macroinvertebrates were collected during summer time in 2007, by using pitfall traps in different sites representing vegetation patches situated on land uplift area on successional gradients in the dune shore of Bothnian on the island of Hailuoto, Northern part of the Gulf of Bothnia, Finland. The sites were divided into six vegetation patches types or open sands, all of them localized on early, deflation zone and late successional stages or ecological subgroups: 1 Empetrum patches or microsites (small-scale element distribution in soil plant-systems in patches of Empetrum nigrum, in early succession; 2 Empetrum nigrum patches in deflation zone; 3 open sand in early succession; 4 open sand in deflation zone; 5 Empetrum nigrum patches in late succession, and 6 open sand in late succession. A total of 19034 specimens belonging to 14 species of Insecta and only one group to Aranea species were caught and identified. Afterwards they were grouped by trophic groups as follows: herbivores, predators and detritivores and calculated their richness, abundance, diversity and evenness for each vegetation type. The data obtained were analyzed by different analytical methods and relevant between them as MRPP for the purpose of identifying the possible differences between groups and habitats, which denoted no statistically significant between the 6 environmental types, but if for the case of composition or populations general diversity as abundance, richness, evenness, diversity. It is enclosed too Correspondence Analysis (CA and cluster analysis for epigeus invertebrates species assemblages. As a support to analysis of results we added on ended the species-accumulation curve and estimation curves Chao1 and Jacknife2 for all ecological types.

  2. A comparison of different biotic indices based on benthic macro-invertebrates in italian lakes

    Directory of Open Access Journals (Sweden)

    Laura MARZIALI

    2011-02-01

    Full Text Available Benthic macroinvertebrates samples were taken from Italian lakes with different geological, morphological and chemical characteristics. Thirty-two lowland small and large lakes sampled using a grab in soft substrate were selected to develop biotic indices. Diversity indices based on species numbers - abundances and indices using species sensitivity values were compared. The lakes selected were all situated in the Alpine Ecoregion below 800 m a.s.l. and had similar chemical composition but different levels of anthropogenic pressure. Lakes with data available in different years were included as separate lakes in the analysis; littoralsublittoral samples of large lakes were also separated from profundal samples yielding a total of 41 sites for analysis. Seven different biotic indices were compared: (1 Shannon diversity index (H, (2 weighted Shannon diversity index (Hw including in the calculation a sensitivity value assigned to each species, (3 a benthic quality index based on means of three different environmental variables, measuring trophic status, weighted by species abundances (BQITS, (4 an index based on weighted means using a larger set of environmental variables (BQIENV, (5 a modified BQITS, which included both species numbers and total abundance of individuals (BQIES, (6 an index calculated according to a rarefaction method (ES, (7 an index considering indicator species based on experts judgment (BQIEJ. The indices were compared with a trophic status index (TSI constructed by joining three environmental variables: O2% saturation in the hypolimnion during summer stratification, total phosphorous and transparency during full circulation. Comparisons were also made with another environmental stress index (ENI constructed on a larger number of variables. All the biotic indices had significant correlations with both TSI and ENI. BQIES, WFD compliant and well correlated with TSI and ENI, was selected to tentatively assign the investigated lakes

  3. Sources of beta diversity in estuarine benthic macro-invertebrate communities in the Baltic Sea - North Sea transition

    DEFF Research Database (Denmark)

    Josefson, Alf B.; Göke, Cordula

    Identification of sources of beta diversity, the change of diversity, is important to understand regulation of overall diversity. Additive partitioning of diversity (species richness and expH) compared to random, was performed on a quantitative benthic macro-invertebrate collection of > 400 species...... regions. The study indicates control of beta diversity by both environmental factors and factors related to invertebrate biology, operating at different spatial scales....... regimes (ca 100 km). Contributions of beta to total diversity were high among regions, but minor between sediment types. Thus controlling for the two environmental factors, salinity and sediment type, there was still an unexplained high beta among stations within regions. A significant distance...

  4. Large-scale macroinvertebrate assemblage patterns from least-disturbed wadeable stream sites across the 48 contiguous US states

    Directory of Open Access Journals (Sweden)

    Gerth W. J.

    2013-03-01

    Full Text Available We quantified the patterns in macroinvertebrate assemblages and their associated environmental gradients from 457 least-disturbed wadeable stream sites across the 48 contiguous United States sampled as part of US EPA’s National Wadeable Stream Assessment. The majority of the variation in assemblage composition at the finest taxonomic resolution was related to substrate size, %fastwater habitat, water chemistry, as well as east-west geographic position and elevation. Sites were classified into 5 groups with cluster analysis, and group membership was predicted from environmental data using classification tree analysis (CTA. CTA correctly classified 69.1% of test sites and indicated that groups were distinguished by east-west location, and by factors distinguishing mountain streams from lowland/plains streams. Eastern and western groups that had similar environmental characteristics had very similar coarse scale taxa composition and convergent taxa traits. Ordinations confirmed that composition patterns using coarse level taxa resolution and taxa traits no longer reflected geographic distinctions, but were only related to non-geographic environmental factors. However, composition patterns based on traits, coarse taxa, and macroinvertebrates identified to the finest practical level were all correlated with the same dominant non-geographic environmental gradients.

  5. Sampling benthic macroinvertebrates in a large flood-plain river: Considerations of study design, sample size, and cost

    Science.gov (United States)

    Bartsch, L.A.; Richardson, W.B.; Naimo, T.J.

    1998-01-01

    Estimation of benthic macroinvertebrate populations over large spatial scales is difficult due to the high variability in abundance and the cost of sample processing and taxonomic analysis. To determine a cost-effective, statistically powerful sample design, we conducted an exploratory study of the spatial variation of benthic macroinvertebrates in a 37 km reach of the Upper Mississippi River. We sampled benthos at 36 sites within each of two strata, contiguous backwater and channel border. Three standard ponar (525 cm(2)) grab samples were obtained at each site ('Original Design'). Analysis of variance and sampling cost of strata-wide estimates for abundance of Oligochaeta, Chironomidae, and total invertebrates showed that only one ponar sample per site ('Reduced Design') yielded essentially the same abundance estimates as the Original Design, while reducing the overall cost by 63%. A posteriori statistical power analysis (alpha = 0.05, beta = 0.20) on the Reduced Design estimated that at least 18 sites per stratum were needed to detect differences in mean abundance between contiguous backwater and channel border areas for Oligochaeta, Chironomidae, and total invertebrates. Statistical power was nearly identical for the three taxonomic groups. The abundances of several taxa of concern (e.g., Hexagenia mayflies and Musculium fingernail clams) were too spatially variable to estimate power with our method. Resampling simulations indicated that to achieve adequate sampling precision for Oligochaeta, at least 36 sample sites per stratum would be required, whereas a sampling precision of 0.2 would not be attained with any sample size for Hexagenia in channel border areas, or Chironomidae and Musculium in both strata given the variance structure of the original samples. Community-wide diversity indices (Brillouin and 1-Simpsons) increased as sample area per site increased. The backwater area had higher diversity than the channel border area. The number of sampling sites

  6. Abundance and distribution of benthic macroinvertebrates in offshore soft sediments in Western Lake Huron, 2001-2007

    Science.gov (United States)

    French, J. R. P., III; Schaeffer, J.S.; Roseman, E.F.; Kiley, C.S.; Fouilleroux, A.

    2009-01-01

    Invasive species have had major impacts on the Great Lakes. This is especially true of exotic dreissenid mussels which are associated with decreased abundance of native macroinvertebrates and changes in food availability for fish. Beginning in 2001, we added a benthic macroinvertebrate survey to the USGS-Great Lakes Science Center's annual fall prey fish assessment of Lake Huron to monitor abundance of macrobenthos. Mean abundance of Diporeia, the most abundant benthic taxon in Lake Huron reported by previous investigators, declined greatly between 2001 and 2007. Diporeia was virtually absent at 27-m sites by 2001, decreased and was lost completely from 46-m depths by 2006, but remained present at reduced densities at 73-m sites. Dreissenids in our samples were almost entirely quagga mussels Dreissena bugensis. Zebra mussels Dreissena polymorpha were virtually absent from our samples, suggesting that they were confined to nearshore areas shallower than we sampled. Loss of Diporeia at individual sites was associated with arrival of quagga mussels, even when mussel densities were low. Quagga mussel density peaked during 2002, then decreased thereafter. During the study quagga mussels became established at most 46-m sites, but remained rare at 73-m sites. Length frequency distributions suggest that initial widespread recruitment may have occurred during 2001-2002. Like other Great Lakes, Lake Huron quagga mussels were associated with decreased abundance of native taxa, but negative effects occurred even though dreissenid densities were much lower. Dreissenid effects may extend well into deep oligotrophic habitats of Lake Huron.

  7. Assessment of Streamside Management Zones for Conserving Benthic Macroinvertebrate Communities Following Timber Harvest in Eastern Kentucky Headwater Catchments

    Directory of Open Access Journals (Sweden)

    Joshua K. Adkins

    2016-06-01

    Full Text Available Headwater streams generally comprise the majority of stream area in a watershed and can have a strong influence on downstream food webs. Our objective was to determine the effect of altering streamside management zone (SMZ configurations on headwater aquatic insect communities. Timber harvests were implemented within six watersheds in eastern Kentucky. The SMZ configurations varied in width, canopy retention and best management practice (BMP utilization at the watershed scale. Benthic macroinvertebrate samples collected one year before and four years after harvest indicated few differences among treatments, although post-treatment abundance was elevated in some of the treatment streams relative to the unharvested controls. Jaccard index values were similar across SMZ treatments after logging, indicating strong community overlap. These findings suggest that stream invertebrate communities did respond to the timber harvest, though not negatively. Results also suggest that SMZ criteria for aquatic habitats in steeply sloping topography, including at least 50 percent canopy retention and widths of at least 16.8 m, appear to be adequate for protecting benthic macroinvertebrate communities from logging impacts.

  8. Bathymetric and regional changes in benthic macrofaunal assemblages on the deep Eastern Brazilian margin, SW Atlantic

    Science.gov (United States)

    Bernardino, Angelo Fraga; Berenguer, Vanessa; Ribeiro-Ferreira, Venina P.

    2016-05-01

    Deep-sea continental slopes have valuable mineral and biological resources in close proximity to diverse, undersampled and fragile marine benthic ecosystems. The eastern Brazilian Continental Margin (19.01°S to 21.06°S, 37.88°W to 40.22°W) is an important economic region for both fishing and oil industries, but is poorly understood with respect to the structure of the soft-sediment benthic fauna, their regional distribution and their bathymetric patterns. To identify spatial and temporal patterns of benthic macrofaunal assemblages on the slope (400 to 3000 m), the Espirito Santo Basin Assessment Project (AMBES, coordinated by Cenpes-Petrobras) sampled 42 stations across the Brazilian Eastern Slope during both Summer 2012 and Winter 2013. We found a significant decrease in macrofaunal abundance at the 400 m isobath along the slope near the northern region of the Espirito Santo Basin, suggesting benthic responses to upwelling events towards the south in Campos Basin and southern Espirito Santo Basin. The taxonomic diversity and assemblage composition also changed significantly across depth zones with mid-slope peaks of diversity at 1000-1300 m. In general, macrofaunal assemblages were strongly related to slope depth, suggesting a strong influence of productivity gradients and water mass distribution on this oligotrophic margin. Sediment grain size was marginally important to macrofaunal composition on the upper slope. In general, macrofaunal assemblages on the slope of Espirito Santo Basin are similar to other areas of the SE Brazilian margin, but regional changes in response to productivity and depth need to be considered for management strategies in the face of increasing economic activities off-shore.

  9. Land use influences on benthic invertebrate assemblages in southern Appalachian agricultural streams

    OpenAIRE

    Bennett, Barbara Loraine Jr.

    1998-01-01

    I investigated the role of land use in structuring benthic invertebrate assemblages in agricultural streams in the French Broad River drainage in western North Carolina. I sampled six agricultural streams (3 with cleared headwaters and 3 with forested headwaters) at three points along a gradient (headwaters, a midpoint, and a downstream site). At each site, I measured a variety of physico-chemical parameters, including temperature, chlorophyll a, discharge, nutrients, and suspended solids. ...

  10. Recent benthic foraminiferal assemblages from cold-water coral mounds in the porcupine seabight

    OpenAIRE

    Schönfeld, Joachim; Dullo, Wolf-Christian; Pfannkuche, Olaf; Freiwald, André; Rüggeberg, Andres; Schmidt, Steffi; Weston, Janice

    2011-01-01

    Cold-water coral ecosystems are characterised by a high diversity and population density. Living and dead foraminiferal assemblages from 20 surface sediment samples from Galway and Propeller Mounds were analysed to describe the distribution patterns of benthic foraminifera on coral mounds in relation to different sedimentary facies. Hard substrates were examined to assess the foraminiferal microhabitats and diversities in the coral framework. We recognised 131 different species, of which 27 p...

  11. Evaluation of an alternate method for sampling benthic macroinvertebrates in low-gradient streams sampled as part of the National Rivers and Streams Assessment

    Science.gov (United States)

    Benthic macroinvertebrates are sampled in streams and rivers as one of the assessment elements of the U.S. Environmental Protection Agency’s National Aquatic Resource Surveys. In a 2006 report, the recommendation was made that different yet comparable methods be evaluated for di...

  12. Effect of zinc on diversity of riverine benthic macroinvertebrates: estimation of safe concentrations from field data.

    Science.gov (United States)

    Iwasaki, Yuichi; Kagaya, Takashi; Miyamoto, Ken-Ichi; Matsuda, Hiroyuki; Sakakibara, Mayu

    2011-10-01

    We conducted field surveys at 25 sites in three Japanese catchments to provide conservative estimates of the safe concentration of zinc (Zn) for the protection of riverine macroinvertebrate diversity. The relationships between the Zn concentration and six macroinvertebrate metrics for taxon richness were determined by using regression analysis; this included a piecewise regression model, where two lines are joined at an unknown point. For each metric the piecewise regression model with a zero slope below a threshold concentration was selected as the best model to explain the influence of Zn. Under the assumption that macroinvertebrate diversity reductions of overprotective for macroinvertebrate diversity. Field studies are useful for evaluating the level of protectiveness of safe concentrations (water quality standards) based on individual-level effects from laboratory toxicity tests, and this evaluation process will have a crucial role in implementing more purpose-driven ecological risk managements that aim to protect natural populations and communities. PMID:21721036

  13. Environmental and spatial controls of macroinvertebrate functional assemblages in seagrass ecosystems along the Pacific coast of northern Japan

    Directory of Open Access Journals (Sweden)

    Katsumasa Yamada

    2014-12-01

    Full Text Available The relative contributions of environmental and spatial processes in macroinvertebrate community structure (i.e.,  β-diversity for three functional groups classified on the basis of dispersal ability and microhabitat selection (seagrass-associated [SA], drift-faunal [DF], and benthic-faunal [BF] groups were examined in a seagrass ecosystem along the Sanriku coast of Japan. Variation partitioning was conducted to explain the environmental heterogeneity and spatial arrangement of local communities (i.e., degree of variation in the community for each functional group. Processes determining community structure and metacommunity type differed among the functional groups. The SA group was under greater influence of environmental control, whereas the fractions of β-diversity in the DF and BF groups were explained by only spatial predictors. Thus, even if macroinvertebrate communities live in the same ecosystem, different mechanisms may determine the functional community structure, which depends on ecological traits such as dispersal ability and microhabitat. Ecological processes underlying community assembly differ among functional groups, indicating that the existence and/or dynamics of seagrass patches may affect the variation of faunal functions in an ecosystem.

  14. In situ effects of titanium dioxide nanoparticles on community structure of freshwater benthic macroinvertebrates.

    Science.gov (United States)

    Jovanović, Boris; Milošević, Djuradj; Piperac, Milica Stojković; Savić, Ana

    2016-06-01

    For the first time in the current literature, the effect of titanium dioxide (TiO2) nanoparticles on the community structure of macroinvertebrates has been investigated in situ. Macroinvertebrates were exposed for 100 days to an environmentally relevant concentration of TiO2 nanoparticles, 25 mg kg(-1) in sediment. Czekanowski's index was 0.61, meaning 39% of the macroinvertebrate community structure was affected by the TiO2 treatment. Non-metric multidimensional scaling (NMDS) visualized the qualitative and quantitative variability of macroinvertebrates at the community level among all samples. A distance-based permutational multivariate analysis of variance (PERMANOVA) revealed the significant effect of TiO2 on the macroinvertebrate community structure. The indicator value analysis showed that the relative frequency and abundance of Planorbarius corneus and Radix labiata were significantly lower in the TiO2 treatment than in the control. Meanwhile, Ceratopogonidae, showed a significantly higher relative frequency and abundance in the TiO2 treatment than in the control. PMID:26924756

  15. Patterns of benthic assemblages invaded and non-invaded by Grateloupia turuturu across rocky intertidal habitats

    Science.gov (United States)

    Freitas, Cristiano; Araújo, Rita; Bertocci, Iacopo

    2016-09-01

    Intertidal benthic assemblages invaded and non-invaded by the introduced Asian red alga Grateloupia turuturu were compared at a rocky shore along the NW coast of Portugal. The structure of whole assemblages, the total richness of taxa and the abundance of individual taxa were examined as response variables in two different habitats (rock pools and emergent rock), two shore levels (low and mid intertidal) and two dates of sampling (June 2013 and June 2014). Invaded and non-invaded assemblages differed consistently across habitats and shore levels. Such differences were driven by 13 (with the green alga genus Ulva, the red alga Chondrus crispus and the mussel Mytilus galloprovincialis driving the total dissimilarity) out of the total 37 taxa identified. Individual taxa revealed idiosyncratic patterns, in several cases (C. crispus, M. galloprovincialis, articulated coralline algae of the genus Corallina and the crustose sporophyte of the red alga Mastocarpus stellatus) there were differences in the abundance of a taxon between invaded and non-invaded assemblages varying with levels of some other experimental factors. The total number of taxa was higher in invaded compared to non-invaded assemblages for each combination of habitat and shore level. Patterns of invasion by G. turuturu along the Portuguese continental coast were recently described in terms of its temporal and spatial distribution, but never examined in terms of differences between invaded and non-invaded assemblages. Such information is very limited for other geographic areas where this species is recorded out of its native range of distribution. Therefore, the present study provides a new contribution to the understanding of modifications of native assemblages associated with the invasion of G. turuturu, opening avenues of research aimed at specifically examining the factors and processes likely responsible for the invasion dynamics and success of this species.

  16. Final report (2002-2004): Benthic macroinvertebrate communities of reconstructed freshwater tidal wetlands in the Anacostia River, Washington, D.C

    Science.gov (United States)

    Brittingham, K.D.; Hammerschlag, R.S.

    2006-01-01

    Considerable work has been conducted on the benthic communities of inland aquatic systems, but there remains a paucity of effort on freshwater tidal wetlands. This study characterized the benthic macroinvertebrate communities of recently reconstructed urban freshwater tidal wetlands along the Anacostia River in Washington, D.C. The focus of the study was on the two main areas of Kingman Marsh, which were reconstructed by the U.S. Army Corps of Engineers in 2000 using Anacostia dredge material. Populations from this 'new' marsh were compared to those of similarly reconstructed Kenilworth Marsh (1993) just one half mile upstream, the relic reference Dueling Creek Marsh in the upper Anacostia estuary and the outside reference Patuxent freshwater tidal marsh in an adjacent watershed. Benthic macro invertebrate organisms were collected using selected techniques for evaluation including the Ekman bottom grab sampler, sediment corer, D-net and Hester-Dendy sampler. Samples were collected at least seasonally from tidal channels, tidal mudflats, three vegetation/sediment zones (low, middle and high marsh), and pools over a 3-year period (late 2001-2004). The macroinvertebrate communities present at the marsh sites proved to be good indicators of disturbance and stress (Kingman Marsh), pollution, urban vs. rural location (Kenilworth and Patuxent), and similarities between reconstructed and remnant wetlands (Kenilworth and Dueling Creek). Macroinvertebrate density was significantly greater at Kingman Marsh than Kenilworth Marsh due to more numerous chironomids and oligochaetes. This may reflect an increase in unvegetated sediments at Kingman (even at elevations above natural mudflat) due to grazing pressure from over-abundant resident Canada geese. Unvegetated sediments yielded greater macroinvertebrate abundance but lower richness than vegetated marsh sites. Data collected from this study provides information on the extent that benthic macroinvertebrate communities can serve

  17. Assessment of water chemistry, habitat, and benthic macroinvertebrates at selected stream-quality monitoring sites in Chester County, Pennsylvania, 1998-2000

    Science.gov (United States)

    Reif, Andrew G.

    2004-01-01

    Biological, chemical, and habitat data have been collected from a network of sites in Chester County, Pa., from 1970 to 2003 to assess stream quality. Forty sites in 6 major stream basins were sampled between 1998 and 2000. Biological data were used to determine levels of impairment in the benthic-macroinvertebrate community in Chester County streams and relate the impairment, in conjunction with chemical and habitat data, to overall stream quality. Biological data consisted of benthic-macroinvertebrate samples that were collected annually in the fall. Water-chemistry samples were collected and instream habitat was assessed in support of the biological sampling. Most sites in the network were designated as nonimpacted or slightly impacted by human activities or extreme climatic conditions on the basis of biological-metric analysis of benthic-macroinvertebrate data. Impacted sites were affected by factors, such as nutrient enrichment, erosion and sedimentation, point discharges, and droughts and floods. Streams in the Schuylkill River, Delaware River, and East Branch Brandywine Creek Basins in Chester County generally had low nutrient concentrations, except in areas affected by wastewater- treatment discharges, and stream habitat that was affected by erosion. Streams in the West Branch Brandywine, Christina, Big Elk, and Octoraro Creek Basins in Chester County generally had elevated nutrient concentrations and streambottom habitat that was affected by sediment deposition. Macroinvertebrate communities identified in samples from French Creek, Pigeon Creek (Schuylkill River Basin), and East Branch Brandywine Creek at Glenmoore consistently indicate good stream conditions and were the best conditions measured in the network. Macroinvertebrate communities identified in samples from Trout Creek (site 61), West Branch Red Clay Creek (site 55) (Christina River Basin), and Valley Creek near Atglen (site 34) (Octoraro Creek Basin) indicated fair to poor stream conditions and

  18. Evaluating ethanol-based sample preservation to facilitate use of DNA barcoding in routine freshwater biomonitoring programs using benthic macroinvertebrates.

    Directory of Open Access Journals (Sweden)

    Eric D Stein

    Full Text Available Molecular methods, such as DNA barcoding, have the potential to enhance biomonitoring programs worldwide. Altering routinely used sample preservation methods to protect DNA from degradation may pose a potential impediment to application of DNA barcoding and metagenomics for biomonitoring using benthic macroinvertebrates. Using higher volumes or concentrations of ethanol, requirements for shorter holding times, or the need to include additional filtering may increase cost and logistical constraints to existing biomonitoring programs. To address this issue we evaluated the efficacy of various ethanol-based sample preservation methods at maintaining DNA integrity. We evaluated a series of methods that were minimally modified from typical field protocols in order to identify an approach that can be readily incorporated into existing monitoring programs. Benthic macroinvertebrates were collected from a minimally disturbed stream in southern California, USA and subjected to one of six preservation treatments. Ten individuals from five taxa were selected from each treatment and processed to produce DNA barcodes from the mitochondrial gene cytochrome c oxidase I (COI. On average, we obtained successful COI sequences (i.e. either full or partial barcodes for between 93-99% of all specimens across all six treatments. As long as samples were initially preserved in 95% ethanol, successful sequencing of COI barcodes was not affected by a low dilution ratio of 2∶1, transfer to 70% ethanol, presence of abundant organic matter, or holding times of up to six months. Barcoding success varied by taxa, with Leptohyphidae (Ephemeroptera producing the lowest barcode success rate, most likely due to poor PCR primer efficiency. Differential barcoding success rates have the potential to introduce spurious results. However, routine preservation methods can largely be used without adverse effects on DNA integrity.

  19. A benthic macroinvertebrate survey of Secret Ravine : the effects of urbanization on species diversity and abundance

    OpenAIRE

    de Barruel, Monique; West, Nicole

    2003-01-01

    The population in Placer County, California, is growing four times faster than the state of California. With the increase in population comes a large increase in impervious surfaces such as residential developments, strip malls, roads, and a probable decline in local stream water quality. To test whether the recent developments have impacted a local stream, we compared macroinvertebrate populations in an undeveloped (upstream) and a developed (downstream) reach of Secret Ravine. We sampled...

  20. The role of benthic microhabitats in determining the effects of hydromorphological river restoration on macroinvertebrates

    OpenAIRE

    Verdonschot, R.C.M.; Kail, Jochem; McKie, Brendan G.; Verdonschot, P.F.M.

    2016-01-01

    Despite the large number of river restoration projects carried out worldwide, evidence for strong and long-term positive ecological effects of hydromorphological restoration on macroinvertebrates is scarce. To improve the understanding of the success and failure of restoration measures, a standardized field study was carried out in nineteen paired restored and degraded river sections in mid-sized lowland and mountain rivers throughout Europe. We investigated if there were effects of restorati...

  1. Correlation of Fish and Benthic Macroinvertebrate Communities With Multi-scale Environmental Descriptors in Wadeable Streams of the Yukon River Basin

    Science.gov (United States)

    Bailey, J. L.; Bailey, R. C.; Scott, R. J.

    2005-05-01

    We sampled fish and benthic macroinvertebrates at thirty wadeable stream sites in the Yukon River basin in Yukon Territory, Canada during July, 2004, to establish reference conditions in Yukon River basin stream communities. We also measured water quality (eg. temperature, dissolved oxygen, conductivity, pH), stream flow, substrate characteristics and riparian vegetation at each site. Water samples from each site were subsequently analyzed for nutrients and metals. In addition, catchment area, catchment perimeter, catchment land cover, distance of each site to major water bodies and stream barriers were determined through Geographic Information System and satellite photography analysis. Fish and benthic macroinvertebrate community structures and their relationships with the multi-scale description of the stream environment were quantified with non-metric multidimensional scaling, principal component analysis, and correlation analysis.

  2. Classifying the Health of Connecticut Streams Using Benthic Macroinvertebrates with Implications for Water Management

    Science.gov (United States)

    Bellucci, Christopher J.; Becker, Mary E.; Beauchene, Mike; Dunbar, Lee

    2013-06-01

    Bioassessments have formed the foundation of many water quality monitoring programs throughout the United States. Like many state water quality programs, Connecticut has developed a relational database containing information about species richness, species composition, relative abundance, and feeding relationships among macroinvertebrates present in stream and river systems. Geographic Information Systems can provide estimates of landscape condition and watershed characteristics and when combined with measurements of stream biology, provide a useful visual display of information that is useful in a management context. The objective of our study was to estimate the stream health for all wadeable stream kilometers in Connecticut using a combination of macroinvertebrate metrics and landscape variables. We developed and evaluated models using an information theoretic approach to predict stream health as measured by macroinvertebrate multimetric index (MMI) and identified the best fitting model as a three variable model, including percent impervious land cover, a wetlands metric, and catchment slope that best fit the MMI scores (adj- R 2 = 0.56, SE = 11.73). We then provide examples of how modeling can augment existing programs to support water management policies under the Federal Clean Water Act such as stream assessments and anti-degradation.

  3. Benthic foraminiferal assemblage formation: Theory and observation for the European Arctic margin

    Science.gov (United States)

    Loubere, Paul; Rayray, Shan

    2016-09-01

    We use theory and observation to determine how benthic foraminiferal populations living in a range of sedimentary microenvironments are translated into fossil assemblages along the continental margin of the European Arctic. We examine downcore stained (cell tracker green and rose Bengal) and total species shell abundances through the sediment mixing (bioturbation) zone. This, in combination with porewater geochemical measurements, allows us to establish zones of production and destruction for species' shells, and deduce how the fossil record is being generated by the living community. For many taxa, shell production is high in the upper, oxic, sedimentary layer, but destruction in this zone is also high. Hence, contribution to the fossil record is biased to more infaunal populations and species. Taxa producing near, or below, the anoxic boundary of the sediments are particularly important to the developing fossil record of the fjord environment. We find that taxon relative and absolute abundances change continuously through the biologically active sediment profile. This has implications for reconstructing paleoenvironments using benthic foraminiferal assemblages, and potentially for the geochemistry of individual fossil taxa.

  4. Comparison of fish and macroinvertebrates as bioindicators of Neotropical streams.

    Science.gov (United States)

    Ruaro, Renata; Gubiani, Éder André; Cunico, Almir Manoel; Moretto, Yara; Piana, Pitágoras Augusto

    2016-01-01

    The biomonitoring of aquatic ecosystems in developing countries faces several limitations, especially related to gathering resources. The present study aimed at comparing the responses of fish and benthic macroinvertebrates to environmental change, to identify which group best indicates the differences between reference and impacted streams in southern Brazil. We determined reference and impacted sites based on physical and chemical variables of the water. For the analysis and comparison of biological responses, we calculated 22 metrics and submitted them to a discriminant analysis. We selected from this analysis only six metrics, which showed that the two studied assemblages respond differently to environmental change. A larger number of metrics were selected for macroinvertebrates than for fish in the separate analysis. The metrics selected for macroinvertebrates in the pooled analysis (i.e., fish and macroinvertebrates together) were different from those selected in the separate analysis for macroinvertebrates alone. However, the metrics selected for fish in the pooled analysis were the same selected in the separate analysis for fish alone. The macroinvertebrate assemblage was more effective for distinguishing reference from impacted sites. We suggest the use of macroinvertebrates as bioindicators of Neotropical streams, especially in situations in which time and money are short. PMID:26687088

  5. A biological assessment of streams in the eastern United States using a predictive model for macroinvertebrate assemblages

    Science.gov (United States)

    Carlisle, D.M.; Meador, M.R.

    2007-01-01

    A predictive model (RIVPACS-type) for benthic macroinvertebrates was constructed to assess the biological condition of 1,087 streams sampled throughout the eastern United States from 1993-2003 as part of the U.S. Geological Survey's National Water-Quality Assessment Program. A subset of 338 sites was designated as reference quality, 28 of which were withheld from model calibration and used to independently evaluate model precision and accuracy. The ratio of observed (O) to expected (E) taxa richness was used as a continuous measure of biological condition, and sites with O/E values biologically degraded. Spatiotemporal variability of O/E values was evaluated with repeated annual and within-site samples at reference sites. Values of O/E were regressed on a measure of urbanization in three regions and compared among streams in different land-use settings. The model accurately predicted the expected taxa at validation sites with high precision (SD = 0.11). Within-site spatial variability in O/E values was much larger than annual and among-site variation at reference sites and was likely caused by environmental differences among sampled reaches. Values of O/E were significantly correlated with basin road density in the Boston, Massachusetts (p biological degradation. Taxa that occurred less frequently than predicted by the model were those known to be generally intolerant of a variety of anthropogenic stressors. ?? 2007 American Water Resources Association.

  6. Importance of environmental factors on the richness and distribution of benthic macroinvertebrates in tropical headwater streams

    Science.gov (United States)

    It is essential to understand the interactions between local environmental factors (e.g., physical habitat and water quality) and aquatic assemblages to conserve biodiversity in tropical and subtropical headwater streams. Therefore, we evaluated the relative importance of multipl...

  7. Effects of sewage pollution on the structure of rocky shore macroinvertebrate assemblages

    OpenAIRE

    Cabral-Oliveira, J.; Mendes, S.; Maranhão, P.; Pardal, M.A.

    2014-01-01

    The urgency to find efficient indices and indicators to prevent further deterioration of coastal areas is one of the hot topics in today’s scientific publication. However, a detailed knowledge of community responses to anthropogenic impacts is essential to sustain those indices. The studies on the response of benthic community to sewage pollution on intertidal rocky shores are generally based on visual census and do not take into account the tidal levels. In order to f...

  8. Spatial and temporal influences of environmental conditions on benthic macroinvertebrates in northeast Lake Jesup, central Florida

    Czech Academy of Sciences Publication Activity Database

    Ali, A.; Lobinske, R. J.; Frouz, Jan; Leckel Jr., R. J.

    2003-01-01

    Roč. 66, č. 2 (2003), s. 69-83. ISSN 0098-4590 Grant ostatní: St. Johns River Water Management District(US) 96G345 Institutional research plan: CEZ:AV0Z6066911 Keywords : benthic invertebrates * community * Canonical Correspondence Analysis Subject RIV: EH - Ecology, Behaviour

  9. Benthic macroinvertebrate surveys in Chequamegon Bay in support of invasive species early detection research

    Science.gov (United States)

    This presentation describes the impetus and approach for MED invasive species early detection research generally and presents preliminary results concerning benthic composition and non-native species found in the 2013 Chequamegon Bay survey. The audience is a group of researchers...

  10. Bioturbation of sediments by benthic macroinvertebrates and fish and its implication for pond ecosystems: a review

    Czech Academy of Sciences Publication Activity Database

    Adámek, Z.; Maršálek, Blahoslav

    2013-01-01

    Roč. 21, č. 1 (2013), s. 1-17. ISSN 0967-6120 R&D Projects: GA MPO FR-TI3/196 Institutional research plan: CEZ:AV0Z60050516 Institutional support: RVO:67985939 Keywords : benthic macroinverttebrates * benthivorous fish * bottom- water interface * nutrient cycling * pond management Subject RIV: EF - Botanics Impact factor: 0.960, year: 2013

  11. Development of a Benthic Macroinvertebrate Multimetric Index (MMI) for Neotropical Savanna Headwater Streams

    Science.gov (United States)

    Assessing the ecological impacts of anthropogenic pressures is a key task in environmental management. Multimetric indices (MMIs), based on aquatic assemblage responses to anthropogenic pressures, have been used increasingly throughout the world. The MMI approach is a low-cost, r...

  12. Effects of nutrient enrichment derived from fish farming activities on macroinvertebrate assemblages in a subtropical region of Hong Kong.

    Science.gov (United States)

    Gao, Qin-Feng; Cheung, Kwok-Leung; Cheung, Siu-Gin; Shin, Paul K S

    2005-01-01

    To study the correlation between nutrient enrichment derived from fish farming activities and changes in macrobenthic assemblages, a one-year field study was conducted in Kau Sai Bay marine fish culture zone of Hong Kong. Bimonthly sediment samples were collected at six stations: two at the fish cages, two near the boundary of the fish culture area, and two reference sites further away from the culture area. Sediment physico-chemical characteristics in terms of silt/clay fraction, moisture content, total organic carbon (TOC), total Kjeldahl nitrogen (TKN) and total phosphorus (TP) were analyzed. The macrobenthos (>0.5 mm) present in the sediment were sorted, identified and enumerated. On average, TOC, TKN and TP levels at the fish cage stations were 82.8%, 128.5% and 1315.7% higher than those at the reference stations, respectively. As a result, the N:P molar ratio was greatly reduced from 8.75 at the reference stations to 1.83 at the fish cage stations. Univariate and multivariate analyses revealed that diversity of macrofauna was significantly reduced and community structure differed at the fish cage stations relative to the reference sites. The intermediary stations near the fish culture area showed a transitional state of disturbance. Faunal diversity was negatively correlated with nutrient level, reflecting the adverse impacts of nutrient enrichment derived from fish farming activities on the benthic assemblages. Whilst in subtropical Asia-Pacific trash fish is the major feed for fish culture resulting in a higher nutrient loading and nutrient ratio accumulated in the sediment beneath the fish rafts, the effects of nutrient enrichment on macrobenthic assemblages are comparable to that in temperate waters owing to relatively high sediment metabolism rate and smaller fish culture scale in Hong Kong. PMID:16291200

  13. A survey of benthic assemblages of foraminifera in tropical coastal waters of pulau pinang, malaysia.

    Science.gov (United States)

    Minhat, Fatin Izzati; Yahya, Khairun; Talib, Anita; Ahmad, Omar

    2013-08-01

    The distribution of benthic Foraminifera throughout the coastal waters of Taman Negara Pulau Pinang (Penang National Park), Malaysia was studied to assess the impact of various anthropogenic activities, such as fishing, ecotourism and floating cage culture. Samples were obtained at 200 m intervals within the subtidal zone, extending up to 1200 m offshore at Teluk Bahang, Teluk Aling, Teluk Ketapang and Pantai Acheh. The depth within coastal waters ranged between 1.5 m and 10.0 m, with predominantly muddy substrate at most stations. Water quality analysis showed little variation in micronutrient (nitrite, NO2; nitrate, NO3; ammonia, NH4 and orthophosphate, PO4) concentrations between sampling stations. Temperature (29.6±0.48°C), salinity (29.4±0.28 ppt), dissolved oxygen content (5.4±0.95 mg/l) and pH (8.5± 0.13) also showed little fluctuation between stations. A total of nine genera of foraminifera were identified in the study (i.e., Ammonia, Elphidium, Ammobaculites, Bigenerina, Quinqueloculina, Reopax, Globigerina, Textularia and Nonion). The distribution of benthic foraminifera was dominated by opportunistic groups that have a high tolerance to anthropogenic stressors. Ammonia had the highest frequency of occurrence (84.7%), followed by Bigenerina (50%), Ammobaculites (44.2%) and Elphidium (38.9%). The Ammonia-Elphidium Index (AEI) was used to describe the hypoxic condition of benthic communities at all sites. Teluk Bahang had the highest AEI value. The foraminiferal assemblages and distribution in Teluk Bahang, Teluk Aling, Teluk Ketapang and Pantai Acheh showed no correlation with physical or chemical environmental parameters. PMID:24575240

  14. Quantitative tolerance values for common stream benthic macroinvertebrates in the Yangtze River Delta, Eastern China.

    Science.gov (United States)

    Qin, Chun-Yan; Zhou, Jin; Cao, Yong; Zhang, Yong; Hughes, Robert M; Wang, Bei-Xin

    2014-09-01

    Aquatic organisms' tolerance to water pollution is widely used to monitor and assess freshwater ecosystem health. Tolerance values (TVs) estimated based on statistical analyses of species-environment relationships are more objective than those assigned by expert opinion. Region-specific TVs are the basis for developing accurate bioassessment metrics particularly in developing countries, where both aquatic biota and their responses to human disturbances have been poorly documented. We used principal component analysis to derive a synthetic gradient for four stressor variables (total nitrogen, total phosphorus, dissolved oxygen, and % silt) based on 286 sampling sites in the Taihu Lake and Qiantang River basins (Yangtze River Delta), China. We used the scores of taxa on the first principal component (PC1), which explained 49.8% of the variance, to estimate the tolerance values (TV(r)) of 163 macroinvertebrates taxa that were collected from at least 20 sites, 81 of which were not included in the Hilsenhoff TV lists (TV(h)) of 1987. All estimates were scaled into the range of 1-10 as in TV(h). Of all the taxa with different TVs, 46.3% of TV(r) were lower and 52.4% were higher than TV(h). TV(r) were significantly (p streams in China, particularly in the Yangtze River Delta. PMID:24865385

  15. Isonychia spp. and macroinvertebrate community responses to stressors in streams utilizing the benthic in situ toxicity identification evaluation (BiTIE) method

    International Nuclear Information System (INIS)

    Exposures of caged organisms in situ have proven to be a useful way to improve exposure realism and link to stressor effects in aquatic assessments of hazard or risk. A novel cage system, the benthic in situ toxicity identification evaluation (BiTIE), was developed for benthic macroinvertebrates (surrogate species, resident populations and communities) to separate low and high flow effects, and major chemical classes of stressors in streams. Three resin types were used to separate the chemical stressors in the streams Honey Creek and Little Beavercreek, Ohio, USA: DowexTM OptiporeTM (non-polar organics), zeolite (ammonia), and polywool (control). Isonychia spp. sensitivity was compared to Chironomus tentans, and no significant differences were found (p > 0.05). Isonychia spp. growth (length) showed a stressor response in the zeolite treatments, and community testing revealed improved metric responses in the DowexTM treatments. The BiTIE chamber system demonstrated stressor-response relationships using sublethal and multimetric endpoints. - Use of an indigenous aquatic insect and benthic macroinvertebrate communities allows for discerning the stressors in low and high flows with an in situ TIE approach

  16. Last glacial to Holocene productivity and oxygen changes based on benthic foraminiferal assemblages from the western Alboran Sea

    Science.gov (United States)

    Pérez-Asensio, José N.; Cacho, Isabel; Frigola, Jaime; Pena, Leopoldo D.; Asioli, Alessandra; Kuhlmann, Jannis; Huhn, Katrin

    2016-04-01

    Late glacial to Holocene productivity and oxygen changes in the Alboran Sea were investigated analyzing benthic foraminiferal assemblages from the marine sediment core HER-GC-UB06. This 255 cm-long core was recovered at 946 m water depth in the Alboran Sea (western Mediterranean Sea) and includes homogeneous greyish clays from the last 23 ka. Nowadays, the core site is bathed by the Western Mediterranean Deep Water (WMDW) and near the overlying Levantine Intermediate Water (LIW). Benthic foraminifera from the size fraction >63 μm were identified at species level and counted until reaching at least 300 individuals. Q-mode principal component analyses (PCA) was performed to establish benthic foraminiferal assemblages. In addition, benthic foraminifera were classified according to their microhabitat preferences. Diversity was assessed with several diversity indices. Four benthic foraminiferal assemblages have been identified along the core. The distribution of these assemblages records changes in productivity and oxygen conditions during the last 23 ka. The last glacial and deglaciation interval, 23-12.5 ka, shows low diversity and is characterized by the Nonionella iridea assemblage, which includes Cassidulina laevigata, Bolivina dilatata, Nonionoides turgida and Cibicides pachyderma as secondary taxa. This assemblage can be interpreted as a moderately oxygenated mesotrophic environment with episodic pulses of fresh organic matter. Although general mesotrophic conditions prevail, the Last Glacial Maximum shows a more oligotrophic and better oxygenated setting as suggested by higher abundance of epifaunal-shallow infaunal taxa. In contrast, along the Bølling-Allerød eutrophic conditions with higher productivity and lower oxygenation are recorded by a deep infaunal taxa maximum. During the Younger Dryas (YD) and the earliest Holocene (12.5-10.5 ka), the Bolivina dilatata assemblage dominates coinciding with a lower diversity, especially during the YD. This species

  17. Effects of cutting disturbance in Schoenoplectus californicus (C.A. Mey.) Soják on the benthic macroinvertebrates - doi: 10.4025/actascibiolsci.v33i1.6383 Effects of cutting disturbance in Schoenoplectus californicus (C.A. Mey.) Soják on the benthic macroinvertebrates - doi: 10.4025/actascibiolsci.v33i1.6383

    OpenAIRE

    Norma Luiza Würdig; Gabriela Peixoto Coelho de Souza; Gilberto Gonçalves Rodrigues; Thiago Cesar Lima Silveira

    2011-01-01

    Lagoons are considered protected areas because these systems play a key ecological role. However, the extraction of macrophyte Schoenoplectus californicus is held for manufacture of handcrafts, being an alternative income for riverbank communities. This study evaluated the impact of S. californicus experimental cutting on benthic macroinvertebrates trough a field experiment. Macroinvertebrates were sampled at 1, 12, 26 and 60 days after the macrophyte cutting in demarked plots (1 m²), as well...

  18. A comparison of results from previous and present investigations of benthic macroinvertebrates in the small and shallow Lake Shoji, Fuji Five Lakes, Japan

    Directory of Open Access Journals (Sweden)

    Kimio Hirabayashi

    2012-10-01

    Full Text Available In order to clarify the current status of the benthic community of Lake Shoji, and to examine the difference with the last quantitative data of the lake by Miyadi (1932 and Kitagawa (1973, the distribution of benthic macroinvertebrates in this lake was studied. Also, a comparison of the benthic fauna and density was made between the present and previous studies, with a discussion concerning the succession of benthic macroinvertebrates in relation to changes in the lake bottom environment. On March 1, 2010, and September 7, 2011, bathymetrical sampling surveys were carried out using a standard Ekman-Birge grab at each of the 7 locations in Lake Shoji. The average densities of the benthic communities for all the stations were 4,107 inds. m-2, comprised principally of oligochaetes 50.2%, chironomids 48.6%, and chaoborid 1.2% in March 2010, whereas in September 2011 the average density was 1,185 inds. m-2, and mostly comprised of oligochaetes 86.6% and chironomids 13.4%. On the other hand, the average biomasses (wet weight of these benthic macroinvertebrates in March 2010 were composed of 33.3% oligochaetes, 62.8% chironomid larvae, and 3.9% chaoborid larvae, as opposed to 48.8% oligochaetes and 51.2% chironomid larvae, respectively, in September 2011. Propsilocerus akamusi (Tokunaga, 1938 and Procladius sp. of chironomid larvae were the dominant species, making up 10.0% and 17.6%, respectively, of the total chironomid fauna in density, and 83.2% and 9.2% in biomass in March 2010. The mean density of P. akamusi was about 2.5 times higher than that reported by Kitagawa in the 1970s. In recent years, the number of P. akamusi larvae has tended to increase; they are widely distributed, and the anoxic-layer and anaerobic-layer are thickening, especially during summer to late fall in Lake Shoji, suggesting that the lake is in the process of eutrophication.doi: 10.5324/fn.v31i0.1365.Published online: 17 October 2012

  19. The role of benthic macrophytes and their associated macroinvertebrate community in coastal lagoon resistance to eutrophication

    International Nuclear Information System (INIS)

    Eutrophication is widely recognised as one of the major menaces to coastal environments, particularly enclosed bays and lagoons. Although there is a general understanding of the consequences of eutrophication in these systems, there is a lack of sufficient knowledge concerning biotic feedbacks that influence eutrophication patterns and the resistance capacity of coastal environments. In this paper, the isotope ratios of main producers and consumers of a Mediterranean lagoon were examined in order to elucidate the fate of anthropogenic inputs from the main watercourse flowing into the lagoon. The results of the study of stable isotope data in the Mar Menor lagoon reflected that the whole benthic community plays an important role as a natural 'filter' that removes excess nutrients from the water column and stores them in the sediments, thereby enhancing lagoon resistance to eutrophication.

  20. A Polyethylenetherephthalate (PET) device for sampling freshwater benthic macroinvertebrates Um dispositivo de Polietiltereftalato (PET) para amostragem de macroinvertebrados bênticos de água doce

    OpenAIRE

    Volkmer-Ribeiro, C.; D. L. Guadagnin; R. De Rosa-Barbosa; M. M. Silva; S. Drügg-Hahn; V. L. Lopes-Pitoni; H. A. de O. Gastal; M. P. Barros; L. V. Demaman

    2004-01-01

    A new device to sample freshwater benthic macroinvertebrates was used in a low and sandy stretch of a Brazilian sub-tropical river (the River Caí, Triunfo, RS) and in one of its small tributaries, Bom Jardim brook (Arroio Bom Jardim). In this study, the effectiveness of this device, a PET sampler, was tested at different sites in the river and the brook throughout the four seasons between 2001-2002. Comparisons were made by PCA and ANOVA, both employing a bootstrap procedure based on similari...

  1. A study of the effects of implementing agricultural best management practices and in-stream restoration on suspended sediment, stream habitat, and benthic macroinvertebrates at three stream sites in Surry County, North Carolina, 2004-2007-Lessons learned

    Science.gov (United States)

    Smith, Douglas G.; Ferrell, G.M.; Harned, Douglas A.; Cuffney, Thomas F.

    2011-01-01

    The effects of agricultural best management practices and in-stream restoration on suspended-sediment concentrations, stream habitat, and benthic macroinvertebrate assemblages were examined in a comparative study of three small, rural stream basins in the Piedmont and Blue Ridge Physiographic Provinces of North Carolina and Virginia between 2004 and 2007. The study was designed to assess changes in stream quality associated with stream-improvement efforts at two sites in comparison to a control site (Hogan Creek), for which no improvements were planned. In the drainage basin of one of the stream-improvement sites (Bull Creek), several agricultural best management practices, primarily designed to limit cattle access to streams, were implemented during this study. In the drainage basin of the second stream-improvement site (Pauls Creek), a 1,600-foot reach of the stream channel was restored and several agricultural best management practices were implemented. Streamflow conditions in the vicinity of the study area were similar to or less than the long-term annual mean streamflows during the study. Precipitation during the study period also was less than normal, and the geographic distribution of precipitation indicated drier conditions in the southern part of the study area than in the northern part. Dry conditions during much of the study limited opportunities for acquiring high-flow sediment samples and streamflow measurements. Suspended-sediment yields for the three basins were compared to yield estimates for streams in the southeastern United States. Concentrations of suspended sediment and nutrients in samples from Bull Creek, the site where best management practices were implemented, were high compared to the other two sites. No statistically significant change in suspended-sediment concentrations occurred at the Bull Creek site following implementation of best management practices. However, data collected before and after channel stabilization at the Pauls

  2. Dynamics of coral reef benthic assemblages of the Abrolhos Bank, eastern Brazil: inferences on natural and anthropogenic drivers.

    Science.gov (United States)

    Francini-Filho, Ronaldo B; Coni, Ericka O C; Meirelles, Pedro M; Amado-Filho, Gilberto M; Thompson, Fabiano L; Pereira-Filho, Guilherme H; Bastos, Alex C; Abrantes, Douglas P; Ferreira, Camilo M; Gibran, Fernando Z; Güth, Arthur Z; Sumida, Paulo Y G; Oliveira, Nara L; Kaufman, Les; Minte-Vera, Carolina V; Moura, Rodrigo L

    2013-01-01

    The Abrolhos Bank (eastern Brazil) encompasses the largest and richest coral reefs of the South Atlantic. Coral reef benthic assemblages of the region were monitored from 2003 to 2008. Two habitats (pinnacles' tops and walls) were sampled per site with 3-10 sites sampled within different reef areas. Different methodologies were applied in two distinct sampling periods: 2003-2005 and 2006-2008. Spatial coverage and taxonomic resolution were lower in the former than in the latter period. Benthic assemblages differed markedly in the smallest spatial scale, with greater differences recorded between habitats. Management regimes and biomass of fish functional groups (roving and territorial herbivores) had minor influences on benthic assemblages. These results suggest that local environmental factors such as light, depth and substrate inclination exert a stronger influence on the structure of benthic assemblages than protection from fishing. Reef walls of unprotected coastal reefs showed highest coral cover values, with a major contribution of Montastraea cavernosa (a sediment resistant species that may benefit from low light levels). An overall negative relationship between fleshy macroalgae and slow-growing reef-building organisms (i.e. scleractinians and crustose calcareous algae) was recorded, suggesting competition between these organisms. The opposite trend (i.e. positive relationships) was recorded for turf algae and the two reef-building organisms, suggesting beneficial interactions and/or co-occurrence mediated by unexplored factors. Turf algae cover increased across the region between 2006 and 2008, while scleractinian cover showed no change. The need of a continued and standardized monitoring program, aimed at understanding drivers of change in community patterns, as well as to subsidize sound adaptive conservation and management measures, is highlighted. PMID:23365655

  3. Dynamics of coral reef benthic assemblages of the Abrolhos Bank, eastern Brazil: inferences on natural and anthropogenic drivers.

    Directory of Open Access Journals (Sweden)

    Ronaldo B Francini-Filho

    Full Text Available The Abrolhos Bank (eastern Brazil encompasses the largest and richest coral reefs of the South Atlantic. Coral reef benthic assemblages of the region were monitored from 2003 to 2008. Two habitats (pinnacles' tops and walls were sampled per site with 3-10 sites sampled within different reef areas. Different methodologies were applied in two distinct sampling periods: 2003-2005 and 2006-2008. Spatial coverage and taxonomic resolution were lower in the former than in the latter period. Benthic assemblages differed markedly in the smallest spatial scale, with greater differences recorded between habitats. Management regimes and biomass of fish functional groups (roving and territorial herbivores had minor influences on benthic assemblages. These results suggest that local environmental factors such as light, depth and substrate inclination exert a stronger influence on the structure of benthic assemblages than protection from fishing. Reef walls of unprotected coastal reefs showed highest coral cover values, with a major contribution of Montastraea cavernosa (a sediment resistant species that may benefit from low light levels. An overall negative relationship between fleshy macroalgae and slow-growing reef-building organisms (i.e. scleractinians and crustose calcareous algae was recorded, suggesting competition between these organisms. The opposite trend (i.e. positive relationships was recorded for turf algae and the two reef-building organisms, suggesting beneficial interactions and/or co-occurrence mediated by unexplored factors. Turf algae cover increased across the region between 2006 and 2008, while scleractinian cover showed no change. The need of a continued and standardized monitoring program, aimed at understanding drivers of change in community patterns, as well as to subsidize sound adaptive conservation and management measures, is highlighted.

  4. Dynamics of Coral Reef Benthic Assemblages of the Abrolhos Bank, Eastern Brazil: Inferences on Natural and Anthropogenic Drivers

    OpenAIRE

    Francini-Filho, Ronaldo B.; Coni, Ericka O. C.; Meirelles, Pedro M.; Amado-Filho, Gilberto M.; Thompson, Fabiano L; Pereira-Filho, Guilherme H.; Bastos, Alex C.; Abrantes, Douglas P.; Ferreira, Camilo M.; Fernando Z Gibran; Güth, Arthur Z.; Sumida, Paulo Y. G.; Oliveira, Nara L.; Kaufman, Les; Minte-Vera, Carolina V.

    2013-01-01

    The Abrolhos Bank (eastern Brazil) encompasses the largest and richest coral reefs of the South Atlantic. Coral reef benthic assemblages of the region were monitored from 2003 to 2008. Two habitats (pinnacles' tops and walls) were sampled per site with 3–10 sites sampled within different reef areas. Different methodologies were applied in two distinct sampling periods: 2003–2005 and 2006–2008. Spatial coverage and taxonomic resolution were lower in the former than in the latter period. Benthi...

  5. Reef fish and benthic assemblages of the Trindade and Martin Vaz Island group, southwestern Atlantic

    Directory of Open Access Journals (Sweden)

    Guilherme Henrique Pereira-Filho

    2011-09-01

    Full Text Available The Trindade and Martin Vaz island group (TMVIG is located at about 1,120 km off the Brazilian coast. Despite its importance, highlighted by the presence of several endemic fish species, the TMVIG lacks detailed information on the structure of fish and benthic assemblages. Presented here is the first quantitative assessment of reef fish and benthic assemblages of the TMVIG in a depth gradient ranging from 5 to 45 m. Additional qualitative information on reef assemblages between 45 and 100 m was obtained using advanced gas diving techniques (TRIMIX and a remotely operated vehicle (ROV. Similarly to other Brazilian oceanic islands, the TMVIG possesses depauperated fish and benthic assemblages, possibly due to its isolation and small size in comparison to the mainland. Depth was the most important factor affecting the structure of fish assemblages, with the density of most fish species declining with depth. Deep reefs (> 45 m were characterized by the presence of extensive rhodolith beds and rocky reefs sparsely covered with crustose coralline algae, black coral (Cirripathes sp. and a few massive or plate-like reef corals. Part-time or obligatory planktivorous fishes (e.g. Cephalopholis furcifer and Clepticus brasiliensis also dominated deep reefs. Similar characteristics were recorded in mesophotic reef ecosystems across the Western Atlantic. Evidence of overfishing (obtained here and in other recent studies, the presence of four endemic and restricted range fish species, as well as the increase in number of new (and still undescribed endemic taxa, indicates that the adoption of precautionary conservation measures are urgently needed in order to maintain the fragile and unique ecosystems of the TMVIG.O conjunto insular de Trindade e Martin Vaz (CITMV está localizado a aproximadamente 1.120 km da costa brasileira. Apesar de sua importância, salientada pela presença de diversas espécies endêmicas de peixes, não existem informações detalhadas

  6. Relations Between the Structure of Benthic Macro-Invertebrates and the Composition of Adult Water Beetle Diets from the Dytiscidae Family.

    Science.gov (United States)

    Frelik, Anna; Pakulnicka, Joanna

    2015-10-01

    This paper investigates the relations between the diet structure of predaceous adult water beetles from the Dytiscidae family and the structure of macrofauna inhabiting the same environments. The field studies were carried out from April until September in 2012 and 2013 in 1-mo intervals. In total, >1,000 water beetles and 5,115 benthic macro-invertebrates were collected during the whole period of the study. Subsequently, 784 specimens of adult water beetles (70.6% out of the total sampled) with benthic macro-invertebrates found in their proventriculi, were subject to analysis. The predators were divided into three categories depending on their body size: small beetles (2.3-5.0 mm), medium-sized beetles (13-15 mm), and large beetles (27-37 mm). All adult Dytiscidae consumed primarily Ephemeroptera and Chironomidae larvae. Although Asellidae were numerically dominant inhabitants of the sites, the adult water beetles did not feed on them. The analysis of feeding relations between predators and their prey revealed that abundance of Ephemeroptera, Chironomidae, and larval Dytiscidae between the environment and the diet of adult Dytiscidae were strongly correlated. PMID:26314015

  7. Spatial and temporal distribution of benthic macroinvertebrates in a Southeastern Brazilian river Distribuição espaço-temporal de macroinvertebrados bentônicos em um rio do sudeste brasileiro

    Directory of Open Access Journals (Sweden)

    M. P. Silveira

    2006-05-01

    Full Text Available Benthic macroinvertebrate assemblages are structured according to physical and chemical parameters that define microhabitats, including food supply, shelter to escape predators, and other biological parameters that influence reproductive success. The aim of this study is to investigate spatial and temporal distribution of macroinvertebrate assemblages at the Macaé river basin, in Rio de Janeiro state, Southeastern Brazil. According to the "Habitat Assessment Field Data Sheet - High Gradient Streams" (Barbour et al., 1999, the five sampling sites are considered as a reference condition. Despite the differences in hydrological parameters (mean width, depth and discharge among sites, the physicochemical parameters and functional feeding groups' general structure were similar, except for the less impacted area, which showed more shredders. According to the Detrended Correspondence Analysis based on substrates, there is a clear distinction between pool and riffle assemblages. In fact, the riffle litter substrate had higher taxa in terms of richness and abundance, but the pool litter substrate had the greatest number of exclusive taxa. A Cluster Analysis based on sampling sites data showed that temporal variation was the main factor in structuring macroinvertebrate assemblages in the studied habitats.A fauna de macroinvertebrados bentônicos é estruturada por fatores físicos e químicos que determinam os microhábitats, incluindo a disponibilidade de alimento, a existência de refúgios contra predadores e tempestades, o sucesso reprodutivo e outros parâmetros biológicos. O objetivo deste estudo foi investigar a distribuição espaço-temporal da comunidade de macroinvertebrados bentônicos na bacia do rio Macaé, Estado do Rio de Janeiro, Brasil. De acordo com o Habitat Assessment Field Data Sheet - High Gradient Streams (Barbour et al., 1999, os cinco locais coletados são considerados como referência para propósito de biomonitoramento

  8. Assessing environmental impact from gas and oil exploration in the SW Barents Sea using benthic foraminiferal assemblages

    Science.gov (United States)

    Dijkstra, N.; Junttila, J.; Husum, K.; Carroll, J.; Hald, M.

    2012-04-01

    During the last decades petroleum industry and shipping activities have increased in the SW Barents Sea. Oil exploration wells were drilled in the 1980s with production starting in 2007. These activities are projected to expand in the coming years. As part of the Northern Environmental Waste Management (EWMA) project, a competence cluster for petroleum industry related waste handling, we investigate the impacts of enhanced anthropogenic activities on benthic foraminiferal assemblages in the SW Barents Sea. Sediment cores (0-20 cm) from sites in proximity to two oil- and gas fields are under investigation. These sediment cores, dated with the 210Pb method, represent the last 90 to 150 years. Both dead and living benthic foraminifera (100 µm-1 mm) were counted to elucidate differences in foraminiferal assemblages between pre-impact and recent conditions. In addition, the heavy metal concentrations, persistent organic pollutant (POP) concentrations, grain size and total organic content (TOC) of the sediment cores have been analyzed. Pollution levels of the surface sediments (0-1 cm) are of background to good level (level I-II) according to the definitions of the Water Framework Directorate (WFD). Patterns in living benthic foraminiferal assemblages identified in the sea floor surface sediments, are the result of natural environmental changes such as depth, water mass and sediment composition. Further downcore (1-20 cm) pollution levels are in general of background environmental status (WFD level I). However, at some depth intervals, especially in sediment cores from the near proximity of the oil- and gas- fields, pollution levels are slightly enhanced (WFD level II). Further work will include statistical comparison of dead and living foraminiferal assemblages with sediment pollution levels, sediment properties, and oceanographic conditions. This research contributes to the development of foraminifera as a useful bio-monitoring technique for the Arctic region as

  9. Assessment of the effects of the dry period on the faunal composition of aquatic macroinvertebrate assemblages in two temporary ponds in NW Spain

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    Amaia Pérez-Bilbao

    2014-02-01

    Full Text Available Temporary ponds are habitats that undergo periods of drying and flooding. They have been neglected for many years and changes produced by climatic change will greatly affect them. Thus, nowadays they constitute an endangered ecosystem due to their characteristics and to human pressures. These habitats support a high biological richness with species adapted to extreme conditions. Assuming that hydroperiod is the main factor structuring aquatic assemblages in this type of ecosystem, the aim of this study was to assess the effect of the dry period on the faunal composition and the natural succession process of macroinvertebrate assemblages in two temporary ponds and to analyze the differences between two periods, before and after the dry period. A total of 7225 individuals belonging to 93 macroinvertebrate taxa (Nematoda, Hirudinea, Oligochaeta, Mollusca, Crustacea, Acari, Insecta were collected. The most abundant and richest group were insects. Cluster and Non-Metric Multi-Dimensional Scaling (NMDS analyses showed the clustering of the samples in two groups, before and after the dry period, as we had expected. Thus, there was a change in faunal composition in both ponds, corresponding to a successional process. According to the SIMPER analysis, the most contributive taxa in both ponds were mostly insects and crustaceans. Regarding feeding traits, predators and shredders were the dominant groups. However, there was a change in the trophic structure of the assemblages between the two periods. Most taxa resist the drying season with resting eggs, cocoons or simply by flying to more permanent freshwater bodies. Although the two studied ponds are temporary habitats, they support a different faunal composition hosting species that are endemic or rare at regional or national level. 

  10. Late Pleistocene-Holocene events on the continental slope of the Laptev Sea: Evidence from benthic and planktonic foraminiferal assemblages

    Science.gov (United States)

    Ovsepyan, Ya. S.; Taldenkova, E. E.; Bauch, H. A.; Kandiano, E. S.

    2015-11-01

    This work is dedicated to the study of benthic and planktonic foraminifers and is a contribution to the multidisciplinary investigations of Core PS51/154-11 from the Laptev Sea. The paleoecological analysis of foraminiferal assemblages makes it possible to reconstruct in detail environmental changes on the western continental margin of the Laptev Sea during the Late Pleistocene and Holocene. The examined core dated by the AMS radiocarbon method is divided into intervals that reflect main stages in the regional evolution for the last 17.6 k.y.: early deglaciation, Bølling-Allerød warming, Younger Dryas cooling, transition to the Interglacial, Holocene climatic optimum, Middle-Late Holocene. The presence of subpolar planktonic foraminifers and benthic species Cassidulina neoteretis (Tappan) provides grounds to reconstruct for the continental slope area stages of the enhanced activity of subsurface Atlantic-derived water in the intervals of 12.0-14.7 and 0.6-5.4 ka. The benthic assemblage reflects changes in depositional environments related to the postglacial transgression and also climatic change impacts affecting bioproductivity. The events defined on the basis of foraminifers are correlated with climatic oscillations and changes in circulation of water masses.

  11. Effectiveness of benthic foraminiferal and coral assemblages as water quality indicators on inshore reefs of the Great Barrier Reef, Australia

    Science.gov (United States)

    Uthicke, S.; Thompson, A.; Schaffelke, B.

    2010-03-01

    Although the debate about coral reef decline focuses on global disturbances (e.g., increasing temperatures and acidification), local stressors (nutrient runoff and overfishing) continue to affect reef health and resilience. The effectiveness of foraminiferal and hard-coral assemblages as indicators of changes in water quality was assessed on 27 inshore reefs along the Great Barrier Reef. Environmental variables (i.e., several water quality and sediment parameters) and the composition of both benthic foraminiferal and hard-coral assemblages differed significantly between four regions (Whitsunday, Burdekin, Fitzroy, and the Wet Tropics). Grain size and organic carbon and nitrogen content of sediments, and a composite water column parameter (based on turbidity and concentrations of particulate matter) explained a significant amount of variation in the data (tested by redundancy analyses) in both assemblages. Heterotrophic species of foraminifera were dominant in sediments with high organic content and in localities with low light availability, whereas symbiont-bearing mixotrophic species were dominant elsewhere. A similar suite of parameters explained 89% of the variation in the FORAM index (a Caribbean coral reef health indicator) and 61% in foraminiferal species richness. Coral richness was not related to environmental setting. Coral assemblages varied in response to environmental variables, but were strongly shaped by acute disturbances (e.g., cyclones, Acanthaster planci outbreaks, and bleaching), thus different coral assemblages may be found at sites with the same environmental conditions. Disturbances also affect foraminiferal assemblages, but they appeared to recover more rapidly than corals. Foraminiferal assemblages are effective bioindicators of turbidity/light regimes and organic enrichment of sediments on coral reefs.

  12. Does Nutrient Enrichment Alter the Response of Stream Macroinvertebrates to Disturbance?

    Science.gov (United States)

    Gafner, K.; Robinson, C. T.

    2005-05-01

    We examined the influence of nutrient enrichment on the response of benthic macroinvertebrates to disturbance in springbrooks of an alpine floodplain. Individual stones in three different springs were physically disturbed at frequencies of 0, 4, 8 and 16 days, and then collected on day 32. In another experiment, nutrients (slow-release fertilizer pellets) were added to one of two streams, and stones in both treated as in the first experiment. In both experiments, stones were analyzed for periphyton biomass, total invertebrate density, and the density and relative abundance of four common families: Baetidae, Nemouridae, Chironomidae, and Simuliidae. N, P, and C were analyzed for periphyton, benthic sediments and invertebrates in the 2nd experiment to test for stoichiometric changes resulting from nutrient enrichment. In the 1st experiment, disturbance affected the relative abundance of the four families. Fertilization changed the stoichiometry of periphyton, invertebrates and sediments and altered macroinvertebrate assemblages. Here, the effect of disturbance differed between the two streams, and the non-fertilized stream displayed a similar disturbance response pattern by macroinvertebrates as in the 1st experiment. These results suggest that nutrient enrichment alters the effects of physical disturbance on macroinvertebrates by changing food resource stoichiometry and shifting macroinvertebrate assemblage structure.

  13. Structure and diversity of intertidal benthic diatom assemblages in contrasting shores: a case study from the Tagus estuary(1).

    Science.gov (United States)

    Ribeiro, Lourenço; Brotas, Vanda; Rincé, Yves; Jesus, Bruno

    2013-04-01

    The structure of intertidal benthic diatoms assemblages in the Tagus estuary was investigated during a 2-year survey, carried out in six stations with different sediment texture. Nonparametric multivariate analyses were used to characterize spatial and temporal patterns of the assemblages and to link them to the measured environmental variables. In addition, diversity and other features related to community physiognomy, such as size-class or life-form distributions, were used to describe the diatom assemblages. A total of 183 diatom taxa were identified during cell counts and their biovolume was determined. Differences between stations (analysis of similarity (ANOSIM), R = 0.932) were more evident than temporal patterns (R = 0.308) and mud content alone was the environmental variable most correlated to the biotic data (BEST, ρ = 0.863). Mudflat stations were typically colonized by low diversity diatom assemblages (H' ~ 1.9), mainly composed of medium-sized motile epipelic species (250-1,000 μm(3) ), that showed species-specific seasonal blooms (e.g., Navicula gregaria Donkin). Sandy stations had more complex and diverse diatom assemblages (H' ~ 3.2). They were mostly composed by a large set of minute epipsammic species (<250 μm(3) ) that, generally, did not show temporal patterns. The structure of intertidal diatom assemblages was largely defined by the interplay between epipelon and epipsammon, and its diversity was explained within the framework of the Intermediate Disturbance Hypothesis. However, the spatial distribution of epipelic and epipsammic life-forms showed that the definition of both functional groups should not be over-simplified. PMID:27008515

  14. The impact of an industrial effluent on the water quality, submersed macrophytes and benthic macroinvertebrates in a dammed river of Central Spain.

    Science.gov (United States)

    Gonzalo, Cristina; Camargo, Julio A

    2013-10-01

    This research was conducted in the middle Duratón River (Central Spain), in the vicinity of Burgomillodo Reservoir. An industrial effluent enters the river 300 m downstream from the dam. Fluoride and turbidity levels significantly increased downstream from the effluent, these levels being to some extent affected by differential water releases from the dam. The community of submersed macrophytes exhibited slighter responses and, accordingly, lower discriminatory power than the community of benthic macroinvertebrates, this indicating that metrics and indices based on macroinvertebrates may be more suitable for the biological monitoring of water pollution and habitat degradation in dammed rivers receiving industrial effluents. However, in relation to fluoride bioaccumulation at the organism level, macrophytes (Fontinalis antipyretica and Potamogeton pectinatus) were as suitable bioindicators of fluoride pollution as macroinvertebrates (Ancylus fluviatilis and Pacifastacus leniusculus). Fluoride bioaccumulation in both hard and soft tissues of these aquatic organisms could be used as suitable bioindicator of fluoride pollution (even lower than 1 mg F(-)L(-1)) in freshwater ecosystems. Echinogammarus calvus exhibited a great sensitivity to the toxicity of fluoride ions, with a 96 h LC₅₀ of 7.5 mg F(-)L(-1) and an estimated safe concentration of 0.56 mg F(-)L(-1). The great capacity of E. calvus to take up and retain fluoride during exposures to fluoride ions would be a major cause of its great sensitivity to fluoride toxicity. It is concluded that the observed fluoride pollution might be partly responsible for the absence of this native amphipod downstream from the industrial effluent. PMID:23830885

  15. Comparison of watershed disturbance predictive models for stream benthic macroinvertebrates for three distinct ecoregions in western US

    Science.gov (United States)

    Waite, I.R.; Brown, L.R.; Kennen, J.G.; May, J.T.; Cuffney, T.F.; Orlando, J.L.; Jones, K.A.

    2010-01-01

    The successful use of macroinvertebrates as indicators of stream condition in bioassessments has led to heightened interest throughout the scientific community in the prediction of stream condition. For example, predictive models are increasingly being developed that use measures of watershed disturbance, including urban and agricultural land-use, as explanatory variables to predict various metrics of biological condition such as richness, tolerance, percent predators, index of biotic integrity, functional species traits, or even ordination axes scores. Our primary intent was to determine if effective models could be developed using watershed characteristics of disturbance to predict macroinvertebrate metrics among disparate and widely separated ecoregions. We aggregated macroinvertebrate data from universities and state and federal agencies in order to assemble stream data sets of high enough density appropriate for modeling in three distinct ecoregions in Oregon and California. Extensive review and quality assurance of macroinvertebrate sampling protocols, laboratory subsample counts and taxonomic resolution was completed to assure data comparability. We used widely available digital coverages of land-use and land-cover data summarized at the watershed and riparian scale as explanatory variables to predict macroinvertebrate metrics commonly used by state resource managers to assess stream condition. The "best" multiple linear regression models from each region required only two or three explanatory variables to model macroinvertebrate metrics and explained 41-74% of the variation. In each region the best model contained some measure of urban and/or agricultural land-use, yet often the model was improved by including a natural explanatory variable such as mean annual precipitation or mean watershed slope. Two macroinvertebrate metrics were common among all three regions, the metric that summarizes the richness of tolerant macroinvertebrates (RICHTOL) and some form

  16. Effects of the Terra Nova offshore oil development on benthic macro-invertebrates over 10 years of development drilling on the Grand Banks of Newfoundland, Canada

    Science.gov (United States)

    Paine, Michael D.; DeBlois, Elisabeth M.; Kilgour, Bruce W.; Tracy, Ellen; Pocklington, Patricia; Crowley, Roger D.; Williams, Urban P.; Gregory Janes, G.

    2014-12-01

    This paper describes effects of drilling with water and synthetic-based drilling muds on benthic macro-invertebrates over 10 years at the Terra Nova offshore oil development. As such, the paper provides insight on the effects of relatively new synthetic-based drilling muds (SBMs), and makes an important contribution to our understanding of the long-term chronic effects of drilling on benthic communities. The Terra Nova Field is located approximately 350 km offshore on the Grand Banks of Newfoundland (Canada). Sediment and invertebrate samples were collected in 1997 (baseline) prior to drilling, and subsequently in 2000, 2001, 2002, 2004, 2006, 2008 and 2010. Approximately 50 stations were sampled in each year at distances of less than 1 to approximately 20 km from drill centres. Summary benthic invertebrate community measures examined were total abundance, biomass, richness, diversity and multivariate measures of community composition based on non-Metric Dimensional Scaling (nMDS). Decreases in abundance, biomass and richness were noted at one station located nearest (0.14 km) to a drill centre in some environmental effects monitoring (EEM) years. These decreases coincided with higher levels of tracers of drill muds in sediments (barium and >C10-C21 hydrocarbons). Abundances of selected individual taxa were also examined to help interpret responses when project-related effects on summary measures occurred. Enrichment effects on some tolerant taxa (e.g., the polychaete family Phyllodocidae and the bivalve family Tellinidae) and decreased abundances of sensitive taxa (e.g., the polychaete families Orbiniidae and Paraonidae) were detected to within approximately 1-2 km from discharge source. Lagged responses three to five years after drilling started were noted for Phyllodocidae and Tellinidae, suggesting chronic or indirect effects. Overall, results of benthic community analyses at Terra Nova indicate that effects on summary measures of community composition were

  17. Biodiversity assessment of benthic macroinvertebrates in altitudinal lotic ecosystems of Serra do Cipó (MG, Brazil) Avaliação da biodiversidade de macroinvertebrados bentônicos em ecossistemas lóticos de altitude na Serra do Cipó (MG, Brasil)

    OpenAIRE

    GALDEAN N.; Callisto, M.; F. A. R. BARBOSA

    2001-01-01

    Five lotic systems of Serra do Cipó, south-east Brazil, were investigated in order to assess the existing diversity of benthic macroinvertebrates, habitats-microhabitats, and the available trophic resources. For each river it was analysed the communities of benthic macroinvertebrates and the composition of some taxonomic groups (Plecoptera, Ephemeroptera, Trichoptera and Diptera Chironomidae): the community with Bivalvia Sphaeriidae, Oligochaeta and Ephemeroptera Baetidae (being supposed a cl...

  18. Using benthic macroinvertebrate and fish communities as bioindicators of the Tanshui River basin around the greater Taipei area - multivariate analysis of spatial variation related to levels of water pollution.

    Science.gov (United States)

    Young, Shuh-Sen; Yang, Hsi-Nan; Huang, Da-Ji; Liu, Su-Miao; Huang, Yueh-Han; Chiang, Chung-Ting; Liu, Jin-Wei

    2014-07-01

    After decades of strict pollution control and municipal sewage treatment, the water quality of the Tanshui River increased significantly after pollution mitigation as indicated by the River Pollution Index (RPI). The pollution level of the estuarine region decreased from severe pollution to mostly moderately impaired. The most polluted waters are presently restricted to a flow track length between 15-35 km relative to the river mouth. From July 2011 to September 2012, four surveys of fish and benthic macroinvertebrates were conducted at 45 sampling sites around the Tanshui River basin. The pollution level of all the study area indicated by the RPI could also be explained by the Family Biotic Index (FBI) and Biotic Index (BI) from the benthic macroinvertebrate community, and the Index of Biotic Integrity (IBI) of the fish community. The result of canonical correlation analysis between aquatic environmental factors and community structure indicated that the community structure was closely related to the level of water pollution. Fish species richness in the estuarine area has increased significantly in recent years. Some catadromous fish and crustaceans could cross the moderate polluted water into the upstream freshwater, and have re-colonized their populations. The benthic macroinvertebrate community relying on the benthic substrate of the estuarine region is still very poor, and the water layer was still moderately polluted. PMID:25026081

  19. Using Benthic Macroinvertebrate and Fish Communities as Bioindicators of the Tanshui River Basin Around the Greater Taipei Area — Multivariate Analysis of Spatial Variation Related to Levels of Water Pollution

    Directory of Open Access Journals (Sweden)

    Shuh-Sen Young

    2014-07-01

    Full Text Available After decades of strict pollution control and municipal sewage treatment, the water quality of the Tanshui River increased significantly after pollution mitigation as indicated by the River Pollution Index (RPI. The pollution level of the estuarine region decreased from severe pollution to mostly moderately impaired. The most polluted waters are presently restricted to a flow track length between 15–35 km relative to the river mouth. From July 2011 to September 2012, four surveys of fish and benthic macroinvertebrates were conducted at 45 sampling sites around the Tanshui River basin. The pollution level of all the study area indicated by the RPI could also be explained by the Family Biotic Index (FBI and Biotic Index (BI from the benthic macroinvertebrate community, and the Index of Biotic Integrity (IBI of the fish community. The result of canonical correlation analysis between aquatic environmental factors and community structure indicated that the community structure was closely related to the level of water pollution. Fish species richness in the estuarine area has increased significantly in recent years. Some catadromous fish and crustaceans could cross the moderate polluted water into the upstream freshwater, and have re-colonized their populations. The benthic macroinvertebrate community relying on the benthic substrate of the estuarine region is still very poor, and the water layer was still moderately polluted.

  20. Using Benthic Macroinvertebrate and Fish Communities as Bioindicators of the Tanshui River Basin Around the Greater Taipei Area — Multivariate Analysis of Spatial Variation Related to Levels of Water Pollution

    Science.gov (United States)

    Young, Shuh-Sen; Yang, Hsi-Nan; Huang, Da-Ji; Liu, Su-Miao; Huang, Yueh-Han; Chiang, Chung-Ting; Liu, Jin-Wei

    2014-01-01

    After decades of strict pollution control and municipal sewage treatment, the water quality of the Tanshui River increased significantly after pollution mitigation as indicated by the River Pollution Index (RPI). The pollution level of the estuarine region decreased from severe pollution to mostly moderately impaired. The most polluted waters are presently restricted to a flow track length between 15–35 km relative to the river mouth. From July 2011 to September 2012, four surveys of fish and benthic macroinvertebrates were conducted at 45 sampling sites around the Tanshui River basin. The pollution level of all the study area indicated by the RPI could also be explained by the Family Biotic Index (FBI) and Biotic Index (BI) from the benthic macroinvertebrate community, and the Index of Biotic Integrity (IBI) of the fish community. The result of canonical correlation analysis between aquatic environmental factors and community structure indicated that the community structure was closely related to the level of water pollution. Fish species richness in the estuarine area has increased significantly in recent years. Some catadromous fish and crustaceans could cross the moderate polluted water into the upstream freshwater, and have re-colonized their populations. The benthic macroinvertebrate community relying on the benthic substrate of the estuarine region is still very poor, and the water layer was still moderately polluted. PMID:25026081

  1. Correlations between benthic habitats and demersal fish assemblages — A case study on the Dogger Bank (North Sea)

    Science.gov (United States)

    Sell, Anne F.; Kröncke, Ingrid

    2013-07-01

    The interdependence between groundfish assemblages and habitat properties was investigated on the Dogger Bank in the North Sea. Abiotic habitat parameters considered included topography, hydrographic conditions, sediment composition, and the biotic habitat variable the prevailing benthic invertebrates. Distinct epi- and infauna communities occurred at different locations on the Dogger Bank. Fish assemblages were clearly linked to both the biotic and abiotic habitat characteristics. Overall, fish and benthic communities revealed similar spatial distribution, represented in the respective clusters of characteristic and abundant species. Distribution patterns corresponded with the prevailing abiotic conditions such as depth and sediment composition, which appear to relate to autecological preferences of individual species. The apparently most generalist species, grey gurnard (Eutrigla gurnardus) and dab (Limanda limanda) occurred at all stations and dominated in terms of biomass in most cases. The absolute numbers of grey gurnards were related to the abundance of suitable prey, invertebrate and fish species, which stomach analyses revealed as part of the diet in an independent study during the same research cruise. Haddock (Melanogrammus aeglefinus) and whiting (Merlangius merlangus) were only abundant at deep stations along the flanks of the bank. The occurrence of lemon sole (Microstomus kitt), American plaice (Hippoglossoides platessoides) and cod (Gadus morhua) was also positively correlated with depth, whereas especially lesser weever (Echiichthys vipera), sandeel species and solenette (Buglossidium luteum) occurred predominantly at the shallower sites. At the same time, individual fish species such as solenette and lesser weever were associated with high densities of selected epi- or infauna species.

  2. Analysis of benthic macroinvertebrates and biotic indices to evaluate water quality in rivers impacted by mining activities in northern Chile

    Directory of Open Access Journals (Sweden)

    Alvial I.E.

    2013-02-01

    Full Text Available Catchments in the semiarid regions are especially susceptible to environmental perturbation associated with water scarcity, hydrological variations and overuse by anthropogenic activities. Using multivariate analysis to relate environmental and biological data, and diversity and biotic indices (ChBMWP, ChIBF, we analyzed the macroinvertebrate composition of 12 rivers of the semiarid region of northern Chile. A non-metric multidimensional scaling for macroinvertebrate taxa and a principal component analysis for environmental variables strongly separated upstream sites (e.g. Vacas Heladas and Malo Rivers, which presented low pH and high dissolved metal concentrations, from other sites. Effectively, CCA showed that metals and low pH, associated with the altitudinal gradient, determined the distributional patterns of macroinvertebrates in the Elqui catchment. The causes of these particular conditions could be related to geological processes and human impact. The biotic indices applied to the sampling sites corroborated and reflected these characteristics, with La Laguna and Turbio Rivers showing a diverse macroinvertebrate community and moderate to good water quality, and the Claro River showing favorable conditions for the development of aquatic biota, indicating its better quality relative to other stations. To the middle and low part of the basin, a change in the composition of the community was observed, with species that suggest an impact by an increase in organic matter, due to agricultural activities and urban settlements concentrated in this area. Our results suggest that macroinvertebrate taxa in northern Chile may be exceptional species, adapted to unfavorable geochemical conditions, and emphasize the need for protection of the semiarid basins of the region.

  3. Stable-isotope analysis of a deep-sea benthic-fish assemblage: evidence of an enriched benthic food web.

    Science.gov (United States)

    Boyle, M D; Ebert, D A; Cailliet, G M

    2012-04-01

    In this study, fishes and invertebrates collected from the continental slope (1000 m) of the eastern North Pacific Ocean were analysed using stable-isotope analysis (SIA). Resulting trophic positions (T(P) ) were compared to known diets and habitats from the literature. Dual isotope plots indicated that most species groups (invertebrates and fishes) sorted as expected along the carbon and nitrogen axes, with less intraspecific variability than interspecific variability. Results also indicated an isotopically distinct benthic and pelagic food web, as the benthic food web was more enriched in both nitrogen and carbon isotopes. Trophic positions from SIA supported this finding, resulting in the assignment of fishes to different trophic positions from those expected based on published dietary information. These differences can be explained largely by the habitat of the prey and the percentage of the diet that was scavenged. A mixing model estimated dietary contributions of prey similar to those of the known diet of Bathyraja trachura from stomach-content analysis (SCA). Linear regressions indicated that trophic positions calculated from SIA and SCA, when plotted against B. trachura total length for 32 individuals, exhibited similar variation and patterns. Only the T(P) from SCA yielded significant results (stomach content: P 0·05). PMID:22497394

  4. Eocene benthic foraminiferal assemblages from Central Anatolia (Turkey): Biostratigraphy, stable isotope data, paleoenvironmental and paleontological interpretations

    Science.gov (United States)

    Dinçer, Feyza

    2016-02-01

    Stable isotope (δ13C and δ18O) values from Eocene aged shallow marine deposits in two different basins (Haymana and Kırşehir-Kaman) of Central Anatolia and benthic foraminiferal biostratigraphy's corresponding sequences were analyzed to determine paleontological and paleoenvironmental changes. The shallow marine units (Çayraz and Altıpınar formations), deposited as a result of different geological processes in the same period, show differences in paleontological and geochemical properties of the tests. The geological process controlled by environmental factors affect the formation of the chemical structure of foraminiferal calcite. These Lutetian and Bartonian aged formations are represented by five Shallow Benthic Zones. While, the Çayraz section is represented by SBZ 14-18, Boztepe section is represented by SBZ 13-17. With an increase in temperature, the variety of benthic foraminifera decreased, and Assilina exponens became the dominant species in the warm conditions. The most important proxy is δ13C, which reflects the paleoproductivity (food supply) where benthic foraminifera lived. In addition, food supply can be considered to be a more important factor than temperature, as it controls the diversity and abundance of benthic foraminifera.

  5. Effects of heavy metals pollution on benthic foraminifera assemblage: the Gulf of Gabes, Tunisia

    Science.gov (United States)

    Ayadi, Najla; Zghal, Ihsen; Bouzid, Jalel; Abdennaceur Ouali, Jamel

    2014-05-01

    Benthic foraminifera are amongst the most abundant protists found in huge marine and brackish water habitat. During the last few decades, many researches had been focused on using benthic foraminifera as bioindicators of marine pollution caused by industrial, domestic and agricultural waste, oil or heavy metal contamination. The aim of this research is to investigate heavy metals pollution in superficial sediments in two industrial locations at the Gulf of Gabes and to examine the reaction of benthic foraminifera towards metallic concentration. The Gulf of Gabes, located on the eastern coast of Tunisia, is regarded as an extremely vital zone and considered as one of the most important area for fishing in the country. During last years, the coastal area of this region had known an important demographic and industrial development, leading to the presence of uncontrolled discharge. Fifteen superficial sediment samples were collected along the coastline of Skhira and Ghannouch- Gabes. They have been analyzed for Al, Cd, Cr, Cu, Pb, and Zn concentrations as well as for the species composition of benthic foraminifera. Results show three levels of metallic contamination with high concentration of cadmium and zinc. Thirty five benthic foraminifera species were identified. Ammonia parkinsoniana, Ammonia beccarii, Peneroplis planatus, Triloculina trigonula and Adelosina longirostraare are the most abundant and common species. Increasing pollution results in a lower species diversity as well as population density, with the presence of a barren zone, and more frequent abnormal specimens. A complementary statistical analysis (PCA/FA and matrix correlation) shows that heavy metals are resulting from the same anthropogenic source and negative correlation between faunal parameters (density and diversity) and pollutants concentrations.

  6. Benthic macroinvertebrates and the use of stable isotopes (δ13C and δ15N) in the impact assessment of peatland use on boreal stream ecosystems

    Science.gov (United States)

    Nieminen, Mika L.; Daza Secco, Emmanuela; Nykänen, Hannu; Meissner, Kristian

    2013-04-01

    Stable isotope analysis (SIA) can provide insights into carbon flow dynamics and trophic positions of consumers in food webs. SIA is used in this study, where we assess the possible changes in the basal resources of Finnish boreal stream ecosystems and differences in the impact of two forms of peatland use, forestry and peat mining. About 30% of the total land area of Finland is classified as peatland, of which about 55% has been drained for forestry and about 0.6% is in peat production. Unlike forestry, peat production is regionally less scattered and can thus have measurable local impacts although the total area of peat production is small. Three watersheds were used as study areas. Within each watershed, one stream drains a subcatchment affected only by peat mining, whereas the other stream flows through a subcatchment affected by forestry. The two subcatchment streams merge to form a single stream flowing into a lake. Studied watersheds were subject to no other forms of land use. In addition to the impacted sites, we used two pristine natural mire and two natural forest catchments as controls. We analysed the stable isotopes of carbon (δ13C) and nitrogen (δ15N) from benthic macroinvertebrates, stream bank soil, stream sediment, and dissolved organic carbon (DOC) in stream water. Samples for stable isotope analyses were collected in the summer of 2011 and samples for invertebrate community analyses in the autumn of 2011. Upon sampling we measured several physical parameters at each sampling site. In addition, stream water samples collected in summer and autumn 2012 were analysed for CH4 and CO2 gas concentrations and autumn gas samples also for their δ13C values. Our initial SIA results of invertebrates suggest some degree of discrimination between different sources of OM and possible effects on feeding habits, presumably due to the quality of the basal resources. We will explore this result further by examining not only taxonomical structure, but also the

  7. Coral Reefs at the Northernmost Tip of Borneo: An Assessment of Scleractinian Species Richness Patterns and Benthic Reef Assemblages.

    Directory of Open Access Journals (Sweden)

    Zarinah Waheed

    Full Text Available The coral reefs at the northernmost tip of Sabah, Borneo will be established under a marine protected area: the Tun Mustapha Park (TMP by the end of 2015. This area is a passage where the Sulu Sea meets the South China Sea and it is situated at the border of the area of maximum marine biodiversity, the Coral Triangle. The TMP includes fringing and patch reefs established on a relatively shallow sea floor. Surveys were carried out to examine features of the coral reefs in terms of scleractinian species richness, and benthic reef assemblages following the Reef Check substrate categories, with emphasis on hard coral cover. Variation in scleractinian diversity was based on the species composition of coral families Fungiidae (n = 39, Agariciidae (n = 30 and Euphylliidae (n = 15. The number of coral species was highest at reefs with a larger depth gradient i.e. at the periphery of the study area and in the deep South Banggi Channel. Average live hard coral cover across the sites was 49%. Only 7% of the examined reefs had > 75% hard coral cover, while the majority of the reef sites were rated fair (51% and good (38%. Sites with low coral cover and high rubble fragments are evidence of blast fishing, although the observed damage appeared old. Depth was a dominant factor in influencing the coral species composition and benthic reef communities in the TMP. Besides filling in the information gaps regarding species richness and benthic cover for reef areas that were previously without any data, the results of this study together with information that is already available on the coral reefs of TMP will be used to make informed decisions on zoning plans for conservation priorities in the proposed park.

  8. Coral Reefs at the Northernmost Tip of Borneo: An Assessment of Scleractinian Species Richness Patterns and Benthic Reef Assemblages

    Science.gov (United States)

    Waheed, Zarinah; van Mil, Harald G. J.; Syed Hussein, Muhammad Ali; Jumin, Robecca; Golam Ahad, Bobita; Hoeksema, Bert W.

    2015-01-01

    The coral reefs at the northernmost tip of Sabah, Borneo will be established under a marine protected area: the Tun Mustapha Park (TMP) by the end of 2015. This area is a passage where the Sulu Sea meets the South China Sea and it is situated at the border of the area of maximum marine biodiversity, the Coral Triangle. The TMP includes fringing and patch reefs established on a relatively shallow sea floor. Surveys were carried out to examine features of the coral reefs in terms of scleractinian species richness, and benthic reef assemblages following the Reef Check substrate categories, with emphasis on hard coral cover. Variation in scleractinian diversity was based on the species composition of coral families Fungiidae (n = 39), Agariciidae (n = 30) and Euphylliidae (n = 15). The number of coral species was highest at reefs with a larger depth gradient i.e. at the periphery of the study area and in the deep South Banggi Channel. Average live hard coral cover across the sites was 49%. Only 7% of the examined reefs had > 75% hard coral cover, while the majority of the reef sites were rated fair (51%) and good (38%). Sites with low coral cover and high rubble fragments are evidence of blast fishing, although the observed damage appeared old. Depth was a dominant factor in influencing the coral species composition and benthic reef communities in the TMP. Besides filling in the information gaps regarding species richness and benthic cover for reef areas that were previously without any data, the results of this study together with information that is already available on the coral reefs of TMP will be used to make informed decisions on zoning plans for conservation priorities in the proposed park. PMID:26719987

  9. Benthic Macrofaunal Assemblage in the Arid Zone Mangroves of Gulf of Kachchh - Gujarat

    Institute of Scientific and Technical Information of China (English)

    2007-01-01

    The total benthic macrofauna consisting of 62 species in 5 groups, viz. crustaceans (18), gastropods (17), bivalves (16), polychaetes (9) and fishes (2), was recorded in western Kachchh mangroves near Gujarat. The population densities of benthic macrofauna ranged from 424 to 2393 ind.m-2, the diversity ranged from 1.84 to 2.45 bits ind.-1, the richness varied between 0.82 and 0.98, and the evenness varied between 0.64 and 0.81. Two maximum diversity values were recorded during winter and summer. The salinity ranged from 34 to 44, temperature varied between 17 and 37 ℃, and the acidity ranged from 7 to 8.9.

  10. The Expansion of Dreissena and Long-term Shifts in Benthic Macroinvertebrate Community Structure in Lake Ontario, 1998-2008

    Science.gov (United States)

    The introduction of Dreissena to the Great lakes has profoundly impacted benthic ecosystems, resulting in the decline of native species and dramatic community restructuring. In Lake Ontario, long-term monitoring has yielded a wealth of detailed information regarding both the exp...

  11. A comparative analysis of benthic nematode assemblages from Zostera noltii beds before and after a major vegetation collapse

    Science.gov (United States)

    Materatski, Patrick; Vafeiadou, Anna-Maria; Ribeiro, Rui; Moens, Tom; Adão, Helena

    2015-12-01

    Benthic nematodes are widely regarded as very suitable organisms to monitor potential ecological effects of natural and anthropogenic disturbances in aquatic ecosystems. During 2008, the seagrass beds of Zostera noltii located in the Mira estuary (SW Portugal) disappeared completely. However, during 2009, slight symptoms of natural recovery were observed, a process which has since evolved intermittently. This study aims to investigate changes in patterns of nematode density, diversity, and trophic composition between two distinct habitat conditions: "before" the collapse of seagrass beds, and during the early recovery "after" the seagrass habitat loss, through the analysis of: i) temporal and spatial distribution patterns of nematode communities, and ii) the most important environmental variables influencing the nematode assemblages. The following hypotheses were tested: i) there would be differences in nematode assemblage density, biodiversity and trophic composition during both ecological conditions, "before" and "after"; and ii) there would be differences in nematode assemblage density, biodiversity and trophic composition at different sampling occasions during both ecological conditions. Nematode density and diversity were significantly different between the two ecological situations. A higher density was recorded before, but a higher diversity was evident after the collapse of Z. noltii. In spite of the disturbance caused by the seagrass habitat loss in the Mira estuary, the nematode trophic composition did not significantly differ between the before and after seagrass collapse situations. Despite the significant differences found among sampling occasions, a consistent temporal pattern was not evident. The response of nematode communities following this extreme event exhibited considerable resistance and resilience to the new environmental conditions.

  12. Biodiversity loss in benthic macroinfaunal communities and its consequence for organic mercury trophic availability to benthivorous predators in the lower Hudson River estuary, USA

    International Nuclear Information System (INIS)

    Organic mercury such as methylmercury is not only one of the most toxic substances found in coastal ecosystems but also has high trophic transfer efficiency. In this study, we examined implications of chronically altered benthic macroinfaunal assemblages for organic mercury trophic availability (based on organic mercury intracellular partitioning) to their predators in the Arthur Kill-AK (New York, USA). Despite low species diversity, both density and biomass of benthic macroinvertebrates in AK were significantly higher than those at the reference site. Disproportionately high biomass of benthic macroinvertebrates (mostly polychaetes) in the northern AK resulted in a more than twofold increase ('ecological enrichment') in the trophically available organic mercury pool. These results suggest that altered benthic macroinfaunal community structure in AK may play an important role in organic mercury trophic availability at the base of benthic food webs and potentially in mercury biogeochemical cycling in this severely urbanized coastal ecosystem.

  13. Efficiency of Different Sampling Tools for Aquatic Macroinvertebrate Collections in Malaysian Streams.

    Science.gov (United States)

    Ghani, Wan Mohd Hafezul Wan Abdul; Rawi, Che Salmah Md; Hamid, Suhaila Abd; Al-Shami, Salman Abdo

    2016-02-01

    This study analyses the sampling performance of three benthic sampling tools commonly used to collect freshwater macroinvertebrates. Efficiency of qualitative D-frame and square aquatic nets were compared to a quantitative Surber sampler in tropical Malaysian streams. The abundance and diversity of macroinvertebrates collected using each tool evaluated along with their relative variations (RVs). Each tool was used to sample macroinvertebrates from three streams draining different areas: a vegetable farm, a tea plantation and a forest reserve. High macroinvertebrate diversities were recorded using the square net and Surber sampler at the forested stream site; however, very low species abundance was recorded by the Surber sampler. Relatively large variations in the Surber sampler collections (RVs of 36% and 28%) were observed for the vegetable farm and tea plantation streams, respectively. Of the three sampling methods, the square net was the most efficient, collecting a greater diversity of macroinvertebrate taxa and a greater number of specimens (i.e., abundance) overall, particularly from the vegetable farm and the tea plantation streams (RVmacroinvertebrate collection in Malaysian streams and gathered assemblages that resulted in the determination of similar biological water quality classes using the Family Biotic Index (FBI) and the Biological Monitoring Working Party (BMWP). However, despite a slightly longer processing time, the square net was more efficient (lowest RV) at collecting samples and more suitable for the collection of macroinvertebrates from deep, fast flowing, wadeable streams with coarse substrates. PMID:27019685

  14. Diversity and spatial and temporal variation of benthic macroinvertebrates with respect to the trophic state of Lake Figueira in the South of Brazil

    Directory of Open Access Journals (Sweden)

    Fernanda Blauth de Lima

    2013-12-01

    Full Text Available Benthic macroinvertebrates are widely used in evaluations of environmental impact and recommended in biomonitoring, but little used in Brazilian lentic environments. One of the main objectives has been to explain and predict the distribution of those species according to environmental characteristics. Thus, the study aims to characterize the predominant fauna of the Lake Figueira sediment and its relationship with organic matter and depth, analyzing seasonal variation in communities and aiming to select bioindicators of the trophic state. Sampling was carried out from January 2008 to January 2009, along the lagoon fetch, with an Ekmann-Birge dredge (area 225 cm². Taxon richness was not significantly related with depth and organic matter content, but those variables were highly correlated (r = 0.962; r² = 0.926 and p < 0.001. The constant oxygenation of the whole water column allows the occurrence of organisms, independent of depth and organic matter content. Chironomidae was the most abundant taxon and from the frequency of occurrence, abundance and clustering analysis it was possible to select Larsia sp. , Goeldichironomus maculatus, Xenochironomus sp. , Aedokritus sp. Cladopelma forcipis, Cryptochironomus brasiliensis, Nilothauma sp.1 and Caladomyia sp. C, Tanytarsus sp. , Tanytarsus rhabdomantis and Chironomus gr. salinarius as potential indicators related with the spatiotemporal faunal distribution of Lake Figueira.

  15. Influence of benthic macroinvertebrates on the erodability of estuarine cohesive sediments: Density- and biomass-specific responses

    OpenAIRE

    Kristensen, Erik; Neto, João Magalhães; Lundkvist, Morten; Frederiksen, Lars; Pardal, Miguel Ângelo; Valdemarsen, Thomas; Flindt, Mogens Rene

    2013-01-01

    The impact of three dominating benthic invertebrates on sediment stability and erosion conditions of cohesive sediments in the Mondego Estuary, Portugal, was examined in laboratory annular flume experiments. The purpose was to test how the life habits and body size of the three involved species (Hydrobia ulvae, Nereis diversicolor and Scrobicularia plana) in terms of density or biomass influence sediment erosion. All three species decreased the free-stream erosion threshold (uc) a...

  16. Benthic faunal assemblages from the Holocene middle shelf of the South Evoikos Gulf, central Greece, and their palaeoenvironmental implications

    Science.gov (United States)

    Asimina Louvari, Markella; Tsourou, Theodora; Drinia, Hara; Anastasakis, George

    2013-04-01

    South Evoikos Gulf is an elongate, WNW - ESE trending basin, 60 km long and 15 km wide. Its floor slopes towards the south-east where the basin connects with the Aegean Sea across a 55 m deep sill. The hydrographic network of the area is characterized by Asopos river the small Lilas River and some other ephemeral streams. A sedimentary record spanning the last 13000 calyr BP was recovered at N 38°12'23.1228" E 24°8'14.2404", water depth 70 m, in this gulf. A total of 52 samples from the lower half of the core were quantitatively analyzed for micropalaeontological (benthic foraminifera and ostracods) study in order to reconstruct palaeoenvironmental conditions. This work contributes to the evaluation of the modern environmental problems in South Evoikos Gulf (hypoxia, ecosystem changes, subaquatic vegetation die-off, metal pollution) within the context of the palaeoenvironmental record. In the investigated core, the benthic microfaunal assemblages indicate a marine coastal environment with a gradual transition from a circalittoral to an infralittoral restricted environment. The basal part of the record is characterized by Haynesina depressula Assemblage, which is composed of Haynesina depressula, Textularia agglutinans and Bulimina aculeata.The abundance of Haynesina depressula could be associated with normal marine conditions, but always with periodic brackish water influence. The species composed this assemblage, which are almost all typically infaunal, characterize sediments with a high or medium-high muddy fraction, rich in organic matter available for the organisms that live within the sediment, and low salinity bottom water. Samples from the upper unit of the core indicate a nearshore, inner-shelf facies less than 50 m deep. Common inner-shelf species in these samples include Ammonia beccarii together with Bulimina marginata (Sgarrella & Moncharmont Zei, 1993). The highest abundance of A. beccarii is found between 15 and 20 m water-depth in samples with

  17. DEVELOPMENT OF MULTI-METRIC INDEX BASED ON BENTHIC MACROINVERTEBRATES TO ASSESS RIVER ECOSYSTEM OF A TYPICAL PLAIN RIVER NETWORK IN CHINA%典型平原河网地区底栖动物生物指数筛选及评价基准研究

    Institute of Scientific and Technical Information of China (English)

    陈小华; 康丽娟; 孙从军; 杨青

    2013-01-01

    Bio assessment of benthic macroinvertebrate-based multmietrics is a very effective approach to evaluate quality of river water. Benthic macroinvertebrate assemblages were sampled at 83 sites in Shanghai metropolitan area, a typical dense river network plain. A total of 20 taxa of the benthic macroinvertebrate were collected, including 50% of Mollusca, 30% of Arthropoda and 20% of Annelida. Among 74 sites with living samples, 32 relatively clean sites and 42 polluted sites were separated based on Hilsenhoff biotic index discrminatory criteria. A comprehensive evaluation using 28 widely-used metrics was carried out. Furthermore, 8 metrics were selected as the most sensitive ones based on non-parametric tests (i.e., Mann-Whitney U test and Kolmogorov-Smirnov test). By standard scoring method, eight sensitive metrics were unified and integrated into a multi-metric index on a scale ranging from 8 to 40 for bioassessment at each site. Biocriteria values for benthic macroinvertebrate were proposed by quartation, i.e., 8-15, very poor; 16-23, poor; 24-31, fair; and 32-40, good. Water quality of 9 sites with no living sample were marked as very poor. According to the biocriteria, 41 typical sites were divided into 5 groups. The past 5-year historical data of physico-chemical water quality indicators have significant difference among 5 group sites. Consequently, the discrminatory biocriteria are suitable for the assessment of the river water quality of the Shanghai City.%2011年夏、秋季在上海市全境主要河流的83个断面进行大型底栖动物的采样,共获取底栖动物20个分类单位(种),其中软体动物、环节动物和节肢动物分别占50%、30% 和20%.选取常见的28个生物指数分别进行计算,并采用非参数统计检验方法筛选出8个敏感生物指数.通过记分法对8种敏感生物指数统一量纲后,获得数值范围为8-40的综合生物指数,运用四分法划分了判别河道水环境质量的生物基准:32-40,

  18. Experimental sediment exchanges between natural and constructed wetlands on oil sands leases, near Fort McMurray, Alberta : a look at the relationship between sediment treatments and benthic macroinvertebrates colonizers

    International Nuclear Information System (INIS)

    Oil sand mining activity has been ongoing in the Fort McMurray area since the 1960s, affecting more than 1400 sq. km. of land that has required, and will continue to require, land reclamation. This study examined the feasibility of sequestering mining by-products, a method that has received much attention in recent years. In particular, it examined the suitability of using the mining by-product consolidated tailings as sediment for constructed wetlands. The study isolates the effect of tailings associated water from the effect of consolidated tailings sediment on benthic macroinvertebrate population health. Sediments from reference and opportunistic wetlands were transplanted with sediment from a constructed wetland layered with 4 metres of consolidated tailings. The effects of macrophyte presence in these plots will be examined and contrasted with macroinvertebrates to determine a possible relationship

  19. Benthic foraminiferal assemblages as potential ecological proxies for environmental monitoring in coastal sediment of the Port Klang, Selangor

    Science.gov (United States)

    Chandran, Ravindran; Omar, Ramlan; Leman, Mohd Shafeea; Faiz, Noraswana Nor

    2015-09-01

    This study represents the benthic foraminiferal assemblages, distribution and its composition along the coastal water of Port Klang, Malaysia. A total of 60 samples were collected bimonthly between Jun 2013 and July 2013 at four sites (i.e. West Port, North Port, South Port, Telok Gong and Klang River). There were 20 genera of foraminifera identified from this study sites namely: Acupeina, Ammobaculites, Ammonia, Ammotium, Arenoparella, Asterorotalia, Bolivina, Cibicides,Discorbis, Elphidium, Haplophragmoides, Haynesina, Lagena, Miliammina, Nonion, Pseudorotalia, Quinqueloculina, Spiroloculina, Textularia and Trochammina. The foraminiferal assemblages at West Port was low in diversity (H'=0.58)compared to other sites and low in abundance (804 individuals). Stress tolerant taxa, Ammonia (317 individuals) dominated the distribution in West Port. However, in North Port, high foraminifera diversity (H'=0.67) was noted compared to West Port but lower than Telok Gong and Klang river. Foraminifera at North Port very low in abundance (213 individuals). High Ammonia-Elphidium Index (AEI) value (95) and low FORAM Index (FI=1.04) recorded at South Port indicating the sediments impacted by anthropogenic stressor and therefore the sediments were in hypoxic condition. Higher FORAM Index (F1=2.34) at North Port indicated less human induced activities in the area. There were high density of foraminifera (8918 individuals) and high AEI index value (83) with high Foram Index (F1=1.11) at Telok Gong compared to other sites except North Port. The same results were recorded at Klang River locations which covered 15 sampling stations with high abundance of Ammonia spp indicating disturbed environments. Lower abundance of Elphidium spp in contrast to Ammonia spp suggests that the sediments in all the sampling sites are in hypoxic condition and less oxygen concentrations.

  20. 黄河三角洲石油生产对东营湿地底栖动物群落结构和水质生物评价的影响%The effects of petroleum exploitation on water quality bio-assessment and benthic macro-invertebrate communities in the Yellow River Delta wetland,Dongying

    Institute of Scientific and Technical Information of China (English)

    陈凯; 肖能文; 王备新; 李俊生

    2012-01-01

    The major environmental risks associated with petroleum extraction (e. G. Oil spills and leaks) are well known. There is a lot of information on the impacts of petroleum exploration on benthic communities in foreign studies. In this study, we probed the effects of petroleum exploration on macro-invertebrate assemblages, which are important components of benthic communities in this wetland ecosystem. The object of the investigation was to provide scientific data to guide the management, ecological restoration, conservation of biodiversity, and sustainable development of aquatic ecosystems. Physicochemical variables were measured at 34 sites in the Yellow River Delta wetland, Dongying, China, in October 2009, and benthic macro-invertebrate assemblages were collected using a D-frame net and a Peterson grab. The water body in the study area was oligohaline, its salinity ranging between 0. 05 and 5 ppt. A total of 84 macro-invertebrate taxa, belonging to 70 genera, 41 families, 12 orders, 6 classes, and 3 phyla, were collected. Insecta comprised 52.4% of all benthic invertebrate taxa, of which Odonata and Diptera accounted for 23% and 24% , respectively. The structure anddiversity of macro-invertebrate assemblages were expressed using the Shannon-Wiener index, the Margalef index and the dominance index. Water quality was assessed by the Shannon-Wiener index and the biotic index. The dominant species at most of the sites were either Chironomus spp. Or Glyptotendipes spp. With overall dominance indices of 0. 0315 and 0. 0522, respectively. Pearson correlation analysis showed that the Shannon-Wiener index was negatively correlated with total nitrogen (TN) (r=-0.446, P = 0.02) but was not correlated with any of the other physicochemical variables measured. The biotic index was not correlated with any of the physicochemical variables. The numbers of molluscan taxa were negatively correlated with salinity (r= -0.422, P = 0.028) and positively correlated with pH (r = 0.435, P

  1. SHE analysis for biozonation of benthic foraminiferal assemblages from western arctic ocean

    Science.gov (United States)

    Osterman, L.E.; Buzas, M.A.; Hayek, L.-A.C.

    2002-01-01

    Benthic foraminiferal species abundance in samples from three Mendeleyev Ridge box cores were analyzed by cluster analysis and the newer method of SHE analysis. Previously, the latter technique only has been used on foraminiferal data from depth transects of modern surface sediment samples. Unlike most methods, which initially compare all possible pairs of samples, the SHE procedure results in a linear pattern if a sequence of samples are from the same statistical distribution. A change in slope indicates a statistical change in community structure and / or a change in species composition. The research reported herein is the first application of SHE for the purpose of identifying biozones in sediment core samples for the purpose of stratigraphic correlation. Both cluster analysis and the SHE method provided zonation within cores. However, the cluster method often produced clusters that were difficult to identify and also contained a mixture of samples without stratigraphic continuity. In contrast, SHE resulted in easily identifiable biozones and ensured temporal continuity within them. In general, the cluster analysis produced more zones than the SHE analysis. About 87% of the cluster zones and 64% of the SHE zones were correlated across more than one core. The average age range for correlated biozone boundaries among the three cores, based on radiocarbon dates, was 821 years using cluster analysis and 296 years using SHE. The sequential nature of the analysis, ease in choosing boundaries, and correlation of these boundaries across cores makes SHE the preferred technique.

  2. A comparison of sampling techniques and summary indices for assessment of water quality in the Yamaska River, Québec, based on benthic macroinvertebrates.

    Science.gov (United States)

    Barton, D R; Metcalfe-Smith, J L

    1992-06-01

    The Yamaska River drainage basin in Quebec, Canada, is intensively farmed and heavily polluted with poorly treated domestic and industrial wastes. We investigated the responses of the resident and colonizing components of the benthic macroinvertebrate community to municipal/industrial versus agricultural pollution in the basin, and evaluated the performances of seven diversity and biotic indices for assessing water quality. Samples of riffle-dwelling, infaunal and colonizing invertebrates were collected from 13 stations representing a wide range of types and degrees of pollution using Surber, scoop and artificial substrate samplers. The data were summarized using the indices S (number of taxa), N (number of individuals), H' (Shannon-Wiener's diversity index), D (Simpson's diversity index), BBI (Belgian Biotic Index), TBI (a modification of Hilsenhoff's Biotic Index), % CHIR (percentage of arthropods consisting of Chironomidae) and %OLIGO (percentage of total organisms consisting of Oligochaeta). Different components of the community generated somewhat different assessments and were, therefore, complementary. Community composition, expressed as the percentage of individuals contributed by major taxonomic groups, reflected the kinds of stresses at a station more consistently than did any of the indices. S and TBI came closest to ranking control, agricultural and municipal/industrial sites in accordance with our a priori classification, both between months and among sampling methods. %OLIGO usually separated municipal/industrial sites from control sites. Other indices were found to be less sensitive, accurate or temporally stable, or were otherwise inappropriate for use with certain sampling methods or for certain types of pollution. With most of our samples, all of the summary indices suggested that the impact of agricultural practices on stream ecosystems may be as severe as the impacts of municipal and industrial wastes. PMID:24234488

  3. Efeito de metais Cobre (Cu e Zinco (Zn sobre a comunidade de macroinvertebrados bentônicos em riachos do sul do Brasil = The effect of metals (Cu and Zn on the benthic macroinvertebrate community in streams in southern Brazil

    Directory of Open Access Journals (Sweden)

    Silvia Vendruscolo Milesi

    2008-07-01

    Full Text Available O objetivo deste estudo foi avaliar os efeitos de metais (Cu e Zn sobre a comunidade de macroinverterados bentônicos. Foram amostrados, trimestralmente, entre setembro de 2006 e junho de 2007, organismos e água em oito trechos de riachos de duas bacias hidrográficas influenciadas por urbanização e agricultura. Foram estimados os valores de densidade de organismos, riqueza taxonômica e diversidade de Shannon. Para avaliação dos dados, foram utilizados testes de variância e regressão linear simples. Os resultados demonstraram variabilidade das concentrações dos metais e da macrofauna entre as estações do ano e riachos estudados. O metal Cobre (Cu apresentou influência apenas sobre a densidade Chironomidae e o metal Zinco (Zn apresentou efeito sobre a densidade total da macrofauna bentônica e de Chironomidae. Nenhum dos metais apresentou efeitos sobre ariqueza e diversidade de macroinvertebrados. Os resultados indicam potencial bioindicador da comunidade bentônica na avaliação da qualidade integrada do ambiente.The aim of this study was to evaluate the effect of metals (Cu and Zn on the benthic macroinvertebrate community. The organismsand water were collected quarterly between September 2006 and June 2007, in eight sites in streams of two hydrographic basins, influenced by urbanization and agriculture. The values of organism density, taxonomic richness and the Shannon diversity index were calculated. For data evaluation, tests of variance and simple linear regression were used. The results showed variability in the metal concentration and benthic community among seasons and studied streams. Cu showed influence only on Chironomidae density. Zn demonstrated effect on the benthic community and Chironomidae density. None of the metals presented effect on the macroinvertebrate richness and diversity. The results indicate a bioindicatorpotential of the benthic community in the evaluation of integral quality of the environment.

  4. Influence of benthic macroinvertebrates on the erodability of estuarine cohesive sediments: Density- and biomass-specific responses

    Science.gov (United States)

    Kristensen, Erik; Neto, João Magalhães; Lundkvist, Morten; Frederiksen, Lars; Pardal, Miguel Ângelo; Valdemarsen, Thomas; Flindt, Mogens Rene

    2013-12-01

    The impact of three dominating benthic invertebrates on sediment stability and erosion conditions of cohesive sediments in the Mondego Estuary, Portugal, was examined in laboratory annular flume experiments. The purpose was to test how the life habits and body size of the three involved species (Hydrobia ulvae, Nereis diversicolor and Scrobicularia plana) in terms of density or biomass influence sediment erosion. All three species decreased the free-stream erosion threshold (uc) and increased erosion rate (E), since their feeding activities diminished the surface stabilizing effect of extracellular polymeric substances (EPS) produced by microphytobenthos. S. plana had the highest and H. ulvae the lowest impact when related to density (factor of 29 for uc and factor of 19 for E), while H. ulvae was more important than S. plana when related to biomass (factor of 4 for uc and factor of 6 for E). N. diversicolor had intermediate density-specific (4-6 times higher than H. ulvae) and lowest biomass-specific (2-3 times lower than S. plana) effects on erosion. It appears that faunal erosion impacts preferably should be reported in biomass units for comparative purposes because individual behavioural effects of a small-bodied species like H. ulvae functionally can be relatively more important than those of a 100 times heavier S. plana individual. This is clearly evidenced from the strongly diminished response in suspended Chlorophyll-a content in the presence of the former than the latter species, which is caused by an efficient microphytobenthos grazing by H. ulvae. It is also important to emphasize that the total faunal impact on erosion threshold in a certain area is dictated by combination of contributions from individual species. The total outcome is unpredictable and controlled by synergistic and antagonistic species-specific effects, species interactions as well as environmental and sediment conditions.

  5. Relationships among rotational and conventional grazing systems, stream channels, and macroinvertebrates

    Science.gov (United States)

    Raymond, K.L.; Vondracek, B.

    2011-01-01

    Cattle grazing in riparian areas can reduce water quality, alter stream channel characteristics, and alter fish and macroinvertebrate assemblage structure. The U.S. Department of Agriculture, Natural Resources Conservation Services has recommended Rotational Grazing (RG) as an alternative management method on livestock and dairy operations to protect riparian areas and water quality. We evaluated 13 stream channel characteristics, benthic macroinvertebrate larvae (BML), and chironomid pupal exuviae (CPE) from 18 sites in the Upper Midwest of the United States in relation to RG and conventional grazing (CG). A Biotic Composite Score comprised of several macroinvertebrate metrics was developed for both the BML assemblage and the CPE assemblage. Multi-Response Permutation Procedures (MRPP) indicated a significant difference in stream channel characteristics between RG and CG. Nonmetric Multidimensional Scaling indicated that RG sites were associated with more stable stream banks, higher quality aquatic habitat, lower soil compaction, and larger particles in the streambed. However, neither MRPP nor Mann-Whitney U tests demonstrated a difference in Biotic Composite Scores for BML or CPE along RG and CG sites. The BML and CPE metrics were significantly correlated, indicating that they were likely responding to similar variables among the study sites. Although stream channel characteristics appeared to respond to grazing management, BML and CPE may have responded to land use throughout the watershed, as well as local land use. ?? 2011 Springer Science+Business Media B.V. (outside the USA).

  6. Influence of benthic macro-invertebrate bioturbation on the biogeochemical behaviour of uranium within freshwater sediments; Influence de la bioturbation des macro-invertebres benthiques sur le comportement biogeochimique de l'uranium au sein des sediments d'eau douce

    Energy Technology Data Exchange (ETDEWEB)

    Lagauzere, S.

    2008-06-15

    In freshwater ecosystems, sediments act as an accumulation compartment for metallic pollutants as uranium. Secondary, there can also represent endogenous sources of contamination by resuspension (e.g. flood, bioturbation) or changes of metal speciation that acts upon their bioavailability. Indeed, metallic compounds can be transformed in more or less toxic or inert compounds through physico-chemical (e.g. pH, redox conditions, ionic force) and microbiological variations. These conditions are themselves under the effects of benthic macro-invertebrate activities via bioturbation processes. The main objective of this PhD was to determinate the influence of two benthic macro-invertebrate species (Chironomus riparius and Tubifex tubifex) on the distribution and the transfers of uranium within freshwater sediments. To reach this goal, laboratory experiments were performed in order to (i) assess the effects of uranium on benthic macro-invertebrates, more particularly on their bioturbation activity, (ii) determine the influence of these organisms on uranium behaviour through high resolution physico-chemical measurements (e.g. oxygen optodes, DET gel probes), and (iii) estimate the consequences of these interactions on pelagic organisms via genotoxicity measurements (micronuclei assay and molecular bio-markers analysis on Xenopus laevis). The results demonstrate that bioturbation intensity of macro-invertebrates can be affected in uranium-contaminated sediments, but the two species studied in this work show a relative tolerance. For high uranium concentrations (>100 times the geochemical background level), corresponding however to realistic concentrations in highly contaminated sites, T. tubifex worms are able to maintain a sufficient bioturbation activity that induces a high remobilization of uranium initially associated with sediments to the overlying water (factor 2 to 10). That represents therefore a potential risk for the remaining aquatic biocenose. However, by

  7. Methods of analysis by the U.S. Geological Survey National Water Quality Laboratory; processing, taxonomy, and quality control of benthic macroinvertebrate samples

    Science.gov (United States)

    Moulton, Stephen R., II; Carter, James L.; Grotheer, Scott A.; Cuffney, Thomas F.; Short, Terry M.

    2000-01-01

    Qualitative and quantitative methods to process benthic macroinvertebrate (BMI) samples have been developed and tested by the U.S. Geological Survey?s National Water Quality Laboratory Biological Group. The qualitative processing method is based on visually sorting a sample for up to 2 hours. Sorting focuses on attaining organisms that are likely to result in taxonomic identifications to lower taxonomic levels (for example, Genus or Species). Immature and damaged organisms are also sorted when they are likely to result in unique determinations. The sorted sample remnant is scanned briefly by a second person to determine if obvious taxa were missed. The quantitative processing method is based on a fixed-count approach that targets some minimum count, such as 100 or 300 organisms. Organisms are sorted from randomly selected 5.1- by 5.1-centimeter parts of a gridded subsampling frame. The sorted remnant from each sample is resorted by a second individual for at least 10 percent of the original sort time. A large-rare organism search is performed on the unsorted remnant to sort BMI taxa that were not likely represented in the sorted grids. After either qualitatively or quantitatively sorting the sample, BMIs are identified by using one of three different types of taxonomic assessment. The Standard Taxonomic Assessment is comparable to the U.S. Environmental Protection Agency Rapid Bioassessment Protocol III and typically provides Genus- or Species-level taxonomic resolution. The Rapid Taxonomic Assessment is comparable to the U.S. Environmental Protection Agency Rapid Bioassessment Protocol II and provides Familylevel and higher taxonomic resolution. The Custom Taxonomic Assessment provides Species-level resolution whenever possible for groups identified to higher taxonomic levels by using the Standard Taxonomic Assessment. The consistent use of standardized designations and notes facilitates the interpretation of BMI data within and among water-quality studies

  8. An elutriation apparatus for macroinvertebrates

    Science.gov (United States)

    Worswick, Joseph M., Jr.; Barbour, Michael T.

    1974-01-01

    An inexpensive hydropneumatic apparatus screens macroinvertebrates from bottom samples containing silt, mud, or clay. The elutriator, an acrylic cylinder with screened windows, cemented on an upright plastic funnel, retains benthic fauna while the sediment is washed away. The apparatus yields clean samples and has reduced the time required to sort benthos samples by more than 80%.

  9. Patterns of macroinvertebrate assemblages in a long-term watershed-scale study to address the effects of pulp and paper mill discharges in four US receiving streams.

    Science.gov (United States)

    Flinders, Camille A; Minshall, G Wayne; Ragsdale, Renee L; Hall, Timothy J

    2009-04-01

    Changes in macroinvertebrate communities exposed to pulp and paper mill effluent (PPME) have been seen in mesocosm and short-term field studies. However, long-term patterns of macroinvertebrates in PPME receiving streams have not been examined. We conducted a study of 4 PPME receiving streams (Codorus Creek, PA; the Leaf River, MS; and the McKenzie and Willamette rivers, OR) over 9 y to assess temporal patterns in macroinvertebrate community structure and metrics related to PPME discharge. Study streams represented different ecoregions, warm-/cold-water systems, gradients of PPME concentration (<1%-33%), and mill process types. Bray-Curtis similarity and nonmetric multidimensional scaling showed significant community differences across sites in Codorus Creek, but differences were related to stream temperature patterns and not PPME. In the other study streams, seasonal community differences across years were greater than differences across sites. General linear models were used to examine spatial and temporal variation in macroinvertebrate metric response (% dominant taxa, density, richness, Hilsenhoff Biotic Index [HBI], Simpson's Index, and ash-free dry mass). Mean HBI scores indicated that the macroinvertebrate community reflected fair to very good water quality conditions, with water quality typically classified as "good" at most sites. Significant site differences in macroinvertebrate metric response were uncommon in the Leaf, McKenzie, and Willamette rivers but were seen in all metrics in Codorus Creek, where metric response was spatially variable. In the McKenzie River, there was an increase in mean HBI scores at sites downstream of the mill relative to 1 of the 2 upstream sites. However, significant differences were seen only between 1 upstream and downstream site, and HBI scores at all downstream sites consistently reflected "good" water quality. Significant annual differences in metric response were typical in all rivers. Water quality (pH, conductivity

  10. Relations of benthic macroinvertebrates to concentrations of trace elements in water, streambed sediments, and transplanted bryophytes and stream habitat conditions in nonmining and mining areas of the upper Colorado River basin, Colorado, 1995-98

    Science.gov (United States)

    Mize, Scott V.; Deacon, Jeffrey R.

    2002-01-01

    Intensive mining activity and highly mineralized rock formations have had significant impacts on surface-water and streambed-sediment quality and aquatic life within the upper reaches of the Uncompahgre River in western Colorado. A synoptic study by the U.S. Geological Survey National Water-Quality Assessment Program was completed in the upper Uncompahgre River Basin in 1998 to better understand the relations of trace elements (with emphasis on aluminum, arsenic, copper, iron, lead, and zinc concentrations) in water, streambed sediment, and aquatic life. Water-chemistry, streambed-sediment, and benthic macroinvertebrate samples were collected during low-flow conditions between October 1995 and July 1998 at five sites on the upper Uncompahgre River, all downstream from historical mining, and at three sites in drainage basins of the Upper Colorado River where mining has not occurred. Aquatic bryophytes were transplanted to all sites for 15 days of exposure to the water column during which time field parameters were measured and chemical water-quality and benthic macroinvertebrate samples were collected. Stream habitat characteristics also were documented at each site. Certain attributes of surface-water chemistry among streams were significantly different. Concentrations of total aluminum, copper, iron, lead, and zinc in the water column and concentrations of dissolved aluminum, copper, and zinc were significantly different between nonmining and mining sites. Some sites associated with mining exceeded Colorado acute aquatic-life standards for aluminum, copper, and zinc and exceeded Colorado chronic aquatic-life standards for aluminum, copper, iron, lead, and zinc. Concentrations of copper, lead, and zinc in streambed sediments were significantly different between nonmining and mining sites. Generally, concentrations of arsenic, copper, lead, and zinc in streambed sediments at mining sites exceeded the Canadian Sediment Quality Guidelines probable effect level (PEL

  11. Benthic foraminifera as bioindicators of anthropogenic impacts in two north African lagoons: a comparison with ostracod assemblages

    OpenAIRE

    Ruiz Muñoz, Francisco; González-Regalado Montero, María Luz; Galán Huertos, Emilio; González, María Isabel; Prudencio, María Isabel; Dias, María Isabel; Abad de los Santos, Manuel; Toscano Grande, Antonio; Prenda Marín, José; García García, Edith Xiomara

    2012-01-01

    Numerous investigations have used the foraminiferal assemblages or species as bioindicators. This paper tests the responses of these microorganisms to different environmental changes (heavy metal pollution, treatment stations, artificial inlets, agricultural and urban sewages) and compares them to those observed previously on ostracod assemblages. Foraminifera are more tolerant to these changes, while ostracods present a more specialized response. Numerosas investigaciones han ...

  12. Between-Habitat Variation of Benthic Cover, Reef Fish Assemblage and Feeding Pressure on the Benthos at the Only Atoll in South Atlantic: Rocas Atoll, NE Brazil.

    Science.gov (United States)

    Longo, G O; Morais, R A; Martins, C D L; Mendes, T C; Aued, A W; Cândido, D V; de Oliveira, J C; Nunes, L T; Fontoura, L; Sissini, M N; Teschima, M M; Silva, M B; Ramlov, F; Gouvea, L P; Ferreira, C E L; Segal, B; Horta, P A; Floeter, S R

    2015-01-01

    The Southwestern Atlantic harbors unique and relatively understudied reef systems, including the only atoll in South Atlantic: Rocas atoll. Located 230 km off the NE Brazilian coast, Rocas is formed by coralline red algae and vermetid mollusks, and is potentially one of the most "pristine" areas in Southwestern Atlantic. We provide the first comprehensive and integrative description of the fish and benthic communities inhabiting different shallow reef habitats of Rocas. We studied two contrasting tide pool habitats: open pools, which communicate with the open ocean even during low tides, thus more exposed to wave action; and closed pools, which remain isolated during low tide and are comparatively less exposed. Reef fish assemblages, benthic cover, algal turfs and fish feeding pressure on the benthos remarkably varied between open and closed pools. The planktivore Thalassoma noronhanum was the most abundant fish species in both habitats. In terms of biomass, the lemon shark Negaprion brevirostris and the omnivore Melichtys niger were dominant in open pools, while herbivorous fishes (mainly Acanthurus spp.) prevailed in closed pools. Overall benthic cover was dominated by algal turfs, composed of articulated calcareous algae in open pools and non-calcified algae in closed pools. Feeding pressure was dominated by acanthurids and was 10-fold lower in open pools than in closed pools. Besides different wave exposure conditions, such pattern could also be related to the presence of sharks in open pools, prompting herbivorous fish to feed more in closed pools. This might indirectly affect the structure of reef fish assemblages and benthic communities. The macroalgae Digenea simplex, which is uncommon in closed pools and abundant in the reef flat, was highly preferred in herbivory assays, indicating that herbivory by fishes might be shaping this distribution pattern. The variations in benthic and reef fish communities, and feeding pressure on the benthos between open and

  13. Between-Habitat Variation of Benthic Cover, Reef Fish Assemblage and Feeding Pressure on the Benthos at the Only Atoll in South Atlantic: Rocas Atoll, NE Brazil.

    Directory of Open Access Journals (Sweden)

    G O Longo

    Full Text Available The Southwestern Atlantic harbors unique and relatively understudied reef systems, including the only atoll in South Atlantic: Rocas atoll. Located 230 km off the NE Brazilian coast, Rocas is formed by coralline red algae and vermetid mollusks, and is potentially one of the most "pristine" areas in Southwestern Atlantic. We provide the first comprehensive and integrative description of the fish and benthic communities inhabiting different shallow reef habitats of Rocas. We studied two contrasting tide pool habitats: open pools, which communicate with the open ocean even during low tides, thus more exposed to wave action; and closed pools, which remain isolated during low tide and are comparatively less exposed. Reef fish assemblages, benthic cover, algal turfs and fish feeding pressure on the benthos remarkably varied between open and closed pools. The planktivore Thalassoma noronhanum was the most abundant fish species in both habitats. In terms of biomass, the lemon shark Negaprion brevirostris and the omnivore Melichtys niger were dominant in open pools, while herbivorous fishes (mainly Acanthurus spp. prevailed in closed pools. Overall benthic cover was dominated by algal turfs, composed of articulated calcareous algae in open pools and non-calcified algae in closed pools. Feeding pressure was dominated by acanthurids and was 10-fold lower in open pools than in closed pools. Besides different wave exposure conditions, such pattern could also be related to the presence of sharks in open pools, prompting herbivorous fish to feed more in closed pools. This might indirectly affect the structure of reef fish assemblages and benthic communities. The macroalgae Digenea simplex, which is uncommon in closed pools and abundant in the reef flat, was highly preferred in herbivory assays, indicating that herbivory by fishes might be shaping this distribution pattern. The variations in benthic and reef fish communities, and feeding pressure on the benthos

  14. Spatial variability of macroinvertebrate assemblages and the influence of hydrological and environmental variables along the Sigi River, Tanzania-East Africa

    OpenAIRE

    Masikini, Rosemary Joshua

    2012-01-01

    The study of investigating the spatial and temporal variability of macroinvertebrate and their relation to hydrology, hydraulic and environmental factors was done along the Sigi River during two sampling periods in the dry (March) and wet (May) periods of 2012. The river was demarcated based on slope ranges and five river zones were identified as mountains streams (MS), upper foothills (UF), lower foothills (LF), rejuvenated foothills (REJ) and mature lower river (MR). Samples ...

  15. Temporal trends in algae, benthic invertebrate, and fish assemblages in streams and rivers draining basins of varying land use in the south-central United States, 1993-2007

    Science.gov (United States)

    Miller, Matthew P.; Kennen, Jonathan G.; Mabe, Jeffrey A.; Mize, Scott V.

    2012-01-01

    Site-specific temporal trends in algae, benthic invertebrate, and fish assemblages were investigated in 15 streams and rivers draining basins of varying land use in the south-central United States from 1993–2007. A multivariate approach was used to identify sites with statistically significant trends in aquatic assemblages which were then tested for correlations with assemblage metrics and abiotic environmental variables (climate, water quality, streamflow, and physical habitat). Significant temporal trends in one or more of the aquatic assemblages were identified at more than half (eight of 15) of the streams in the study. Assemblage metrics and abiotic environmental variables found to be significantly correlated with aquatic assemblages differed between land use categories. For example, algal assemblages at undeveloped sites were associated with physical habitat, while algal assemblages at more anthropogenically altered sites (agricultural and urban) were associated with nutrient and streamflow metrics. In urban stream sites results indicate that streamflow metrics may act as important controls on water quality conditions, as represented by aquatic assemblage metrics. The site-specific identification of biotic trends and abiotic–biotic relations presented here will provide valuable information that can inform interpretation of continued monitoring data and the design of future studies. In addition, the subsets of abiotic variables identified as potentially important drivers of change in aquatic assemblages provide policy makers and resource managers with information that will assist in the design and implementation of monitoring programs aimed at the protection of aquatic resources.

  16. Freshwater Macroinvertebrates.

    Science.gov (United States)

    Nalepa, T. F.

    1978-01-01

    Presents a literature review of freshwater biology particularly freshwater macroinvertebrates and their effect on water pollution, covering publications of 1976-77. A list of 158 references is also presented. (HM)

  17. Ensamble de crustáceos bentónicos en un lago salino tropical Benthic crustaceans assemblage in a tropical, saline lake

    Directory of Open Access Journals (Sweden)

    Ma. del Carmen Hernández

    2010-10-01

    Full Text Available El presente trabajo reconoce la composición, estructura y distribución espacial del ensamble de crustáceos bentónicos de Alchichica, un lago salino tropical ubicado en el extremo oriental del altiplano mexicano. El lago presenta una riqueza taxonómica de crustáceos bentónicos compuesta por 1 anfípodo (Hyalella azteca, 1 isópodo (Caecidotea williamsi y 2 ostrácodos (Limnocythere inopinata y Candona sp.. Comparada con otros lagos tropicales, la riqueza de especies es reducida. A pesar de lo anterior, es importante mencionar el grado elevado de endemismo representado por C. williamsi, recientemente descrita para el lago Alchichica; adicionalmente, es factible que tanto Candona como H. azteca sean especies nuevas y endémicas del lago. Los crustáceos bentónicos se distribuyen desde la zona litoral hasta la zona más profunda del lago (62 m con abundancias y riqueza taxonómica variables. Los ostrácodos fueron los crustáceos que con mayor frecuencia se recolectaron en el lago, en la zona litoral, en el talud, y en la zona profunda de la que son habitantes exclusivos. Los anfípodos constituyeron el segundo grupo en abundancia de la zona litoral y talud y estuvieron ausentes en la zona profunda. Los isópodos sólo se encuentran asociados a los depósitos de tufa, hábitat característico del lago que se extiende a lo largo del talud, por lo que con las técnicas de muestreo tradicional empleadas en el presente estudio no fueron capturados. En este ensamble de crustáceos predominan las especies de desarrollo directo y con posiciones tróficas que incluyen componentes herbívoros (H. azteca, omnívoros (C. williamsi y bacterívoros (L. inopinata y Candona sp..This work acknowledges the composition, structure and spatial distribution of the benthic crustaceans assemblage of Alchichica, a tropical saline lake located in the easternmost portion of the Mexican highlands. The benthic crustaceans' assemblage was comprised by 1 amphipod

  18. Foote Brook Macroinvertebrate Biomonitoring-Phase I in Johnson, Vermont

    Data.gov (United States)

    Vermont Center for Geographic Information — The Foote Brook Biomonitoring Project, Phase I geospatial dataset consists of data from the biomonitoring of benthic macroinvertebrates at three sites located along...

  19. A benthic macroinvertebrate size spectra index for implementing the Water Framework Directive in coastal lagoons in Mediterranean and Black Sea ecoregions

    OpenAIRE

    Basset, Alberto; Barbone, Enrico; Borja, Angel; BRUCET SANDRA; Pinna, Maurizio; D. QUINTANA Xavier; REIZOPOULOU Sophia; Rosati, Ilaria; SIMBOURA Mika

    2010-01-01

    Size spectra show common patterns of variation among ecosystem types, functional guilds and taxonomic groups, as well as predictable responses to pressures. Here, we extend the size spectra approach to macroinvertebrate ecological status assessment in transitional waters, by developing, testing and validating a multi-metric index of size spectra sensitivity (ISS), which integrates size structure metrics with metrics describing the sensitivity of size classes to anthropogenic distu...

  20. Western Indian Ocean circulation and climate variability on different time scales. A study based on stable oxygen and carbon isotopes, benthic foraminiferal assemblages and Mg/Ca paleothermometry

    Energy Technology Data Exchange (ETDEWEB)

    Romahn, Sarah

    2014-08-19

    In order to understand the Earth's climate evolution it is crucial to evaluate the role of low-latitude oceans in the global climate system, as they are connected to both hemispheres via atmospheric and oceanic circulation and thus hold the potential to disentangle the asynchronicity of short-term Pleistocene climate variability. However, the potential of low latitude oceans to respond to and force large-scale changes of the climate system is still debated. The aim of this thesis is to examine and to understand the causal relationship of both atmospheric and oceanic changes in the tropical western Indian Ocean on centennial-, millennial and glacial-interglacial timescales. For this purpose I investigated stable oxygen and carbon isotope compositions of both planktic and benthic foraminiferal tests, Mg/Ca ratios of planktic foraminiferal tests as well as benthic foraminiferal assemblages and sedimentary geochemical parameters on two sediment cores (GeoB12615-4, 446 m and GeoB12616-4, 1449 m) from the continental slope off Tanzania, East Africa.

  1. Ancient fish and recent invaders: white sturgeon Acipenser transmontanus diet response to invasive-species-mediated changes in a benthic prey assemblage

    Science.gov (United States)

    Zeug, Steven C; Brodsky, Annie; Kogut, Nina; Stewart, Robin; Merz, Joe

    2014-01-01

    Invasive organisms can have significant impacts on native species, and the San Francisco Estuary (SFE), California, USA, is one of the world's most invaded estuaries. Decline of native white sturgeon Acipenser transmontanus abundance in the SFE has been acknowledged, but underlying mechanisms are poorly understood. Invasion by the overbite clam Potamocorbula amurensis has drastically altered the SFE benthic prey community, yet little is known about how this change has affected sturgeon diets. We investigated changes in the diet of white sturgeon following the overbite clam invasion and subsequent shift in the SFE benthic prey assemblage. Gut content analysis was used to compare white sturgeon prey composition and importance between the pre- and post-invasion periods. Additionally, stable isotope analysis was employed to estimate the assimilation of prey items to sturgeon biomass. Overbite clams dominated diets in the post-invasion period, accounting for 82 to 93% of total volume. Stable isotope analysis confirmed the importance of this prey item, although their assimilated contribution to sturgeon biomass was estimated to be less (70 to 83%) than gut contents indicated. The frequency of fish in white sturgeon guts increased in the post-invasion period, and isotope analysis indicated relatively large contributions of fish to sturgeon biomass (3.7 to 19%). The trophic adaptability of white sturgeon has allowed them to exploit this new prey source (overbite clam). Future conservation and restoration efforts must consider a potentially destabilized food web given the large importance of a single prey item.

  2. The use of rapid bioassessment protocols to describe fish and benthic macroinvertebrate communities in three creeks near the Little River National Wildlife Refuge, McCurtain County, Oklahoma

    Data.gov (United States)

    US Fish and Wildlife Service, Department of the Interior — Selected metrics from the Rapid Bioassessment Protocols (RBPs), published by the U.S. Environmental Protection Agency, were used to describe fish and benthic...

  3. The health of benthic diatom assemblages in lower stretch of a lesser Himalayan glacier-fed river, Mandakini

    Indian Academy of Sciences (India)

    Prakash Nautiyal; Asheesh Shivam Mishra; Jyoti Verma

    2015-03-01

    This study examines the ecological state of epilithic diatom assemblages along the lower stretch of Mandakini, a glacier-fed Himalayan river. The diatoms were sampled at four stations during winter and summer, only once in each season. Valve counts were obtained from Naphrax mounts prepared from each sample. Assemblages were recorded for each location. The software OMNIDIA Ver. 5.3 was used for computing the ecological values from the sample counts. Normally Achnanthidium spp. dominated the assemblages, except Nitzschia fonticola (Grunow) at S1 (Kund) and Encyonema minutum (Hilse in Rabh) at S4 (Rudraprayag), only during summer. The ecological values revealed that the assemblages were in -mesosaprobic and mésotraphentic states. However, at S4, trophic state was observed to be eutraphentic. Louis Leclercq index indicated that organic pollution was nonexistent, while the anthropogenic eutrophication was low except at S2 (Tilwara) and S3 (Medanpur) in summer and was moderate at S4 in winter characterized by a lean flow. The most abundant indicator taxa for anthropogenic eutrophication are varied; Cymbella tumida (Brebisson-Van Heurck) at S1, Encyonema minutum at S2, S4 while Surirella aungusta (Kutzing) at S3. Ordination showed that the taxa indicating degradation and anthropogenic eutrophication figured as characteristic taxa at respective locations.

  4. Spatial and temporal benthic species assemblage responses with a deployed marine tidal energy device: a small scaled study.

    Science.gov (United States)

    Broadhurst, Melanie; Orme, C David L

    2014-08-01

    The addition of man-made structures to the marine environment is known to increase the physical complexity of the seafloor, which can influence benthic species community patterns and habitat structure. However, knowledge of how deployed tidal energy device structures influence benthic communities is currently lacking. Here we examined species biodiversity, composition and habitat type surrounding a tidal energy device within the European Marine Energy Centre test site, Orkney. Commercial fishing and towed video camera techniques were used over three temporal periods, from 2009 to 2010. Our results showed increased species biodiversity and compositional differences within the device site, compared to a control site. Both sites largely comprised of crustacean species, omnivore or predatory feeding regimes and marine tide-swept EUNIS habitat types, which varied over the time. We conclude that the device could act as a localised artificial reef structure, but that further in-depth investigations are required. PMID:24840255

  5. Biogenic reefs affect multiple components of intertidal soft-bottom benthic assemblages: the Lanice conchilega case study

    Science.gov (United States)

    De Smet, Bart; D'Hondt, An-Sofie; Verhelst, Pieterjan; Fournier, Jérôme; Godet, Laurent; Desroy, Nicolas; Rabaut, Marijn; Vincx, Magda; Vanaverbeke, Jan

    2015-01-01

    Biogenic reefs composed of the tube-building polychaete Lanice conchilega are important from a conservation point of view because they noticeably increase the biodiversity in otherwise species poor environments. However, up to now, little or no attention has been paid to the intertidal epi- and hyperbenthic communities associated with the reefs. Therefore, this is the first study which focuses on the effect of L. conchilega reefs on the entire bentho-pelagic community at two different locations. Environmental variables were measured and macro-, epi- and hyperbenthic communities were sampled within a L. conchilega reef and a control area at two locations in France: the bay of the Mont Saint-Michel (BMSM) and Boulogne-sur-Mer (Boulogne). The effect of the reef presence on the benthic community was studied with a 3-factor (Reef, Location and Period) Permanova. In addition, the relationship between the benthic community and the environmental variables was investigated using Distance-based linear models (DistLM). Most collected organisms were sampled in the reef area (macrobenthos: 91%, epibenthos: 81% and hyperbenthos: 78.5%) indicating that, independent of the location, the L. conchilega reefs positively affect all three associated benthic communities. However, the extent of the effect seems to be most pronounced for the macrobenthos and less distinct in case of the hyperbenthos. The macro-, and epibenthos are mainly structured by biotic variables (L. conchilega density and macrobenthic food availability respectively), while the hyperbenthos is rather structured by environmental variables. In general, L. conchilega reefs do not only affect abundances and diversity but they substantially steer the structure of the intertidal benthic sandy beach ecosystem.

  6. Predicted macroinvertebrate response to water diversion from a montane stream using two-dimensional hydrodynamic models and zero flow approximation

    Science.gov (United States)

    Holmquist, Jeffrey G.; Waddle, Terry J.

    2013-01-01

    We used two-dimensional hydrodynamic models for the assessment of water diversion effects on benthic macroinvertebrates and associated habitat in a montane stream in Yosemite National Park, Sierra Nevada Mountains, CA, USA. We sampled the macroinvertebrate assemblage via Surber sampling, recorded detailed measurements of bed topography and flow, and coupled a two-dimensional hydrodynamic model with macroinvertebrate indicators to assess habitat across a range of low flows in 2010 and representative past years. We also made zero flow approximations to assess response of fauna to extreme conditions. The fauna of this montane reach had a higher percentage of Ephemeroptera, Plecoptera, and Trichoptera (%EPT) than might be expected given the relatively low faunal diversity of the study reach. The modeled responses of wetted area and area-weighted macroinvertebrate metrics to decreasing discharge indicated precipitous declines in metrics as flows approached zero. Changes in area-weighted metrics closely approximated patterns observed for wetted area, i.e., area-weighted invertebrate metrics contributed relatively little additional information above that yielded by wetted area alone. Loss of habitat area in this montane stream appears to be a greater threat than reductions in velocity and depth or changes in substrate, and the modeled patterns observed across years support this conclusion. Our models suggest that step function losses of wetted area may begin when discharge in the Merced falls to 0.02 m3/s; proportionally reducing diversions when this threshold is reached will likely reduce impacts in low flow years.

  7. Estrutura da comunidade de macroinvertebrados bentônicos de um riacho de serra em Itatinga, São Paulo, Brasil Structure of a benthic macroinvertebrates community in a mountain stream in Itatinga, São Paulo, Brazil

    Directory of Open Access Journals (Sweden)

    Ludmilla O. Ribeiro

    2005-09-01

    Full Text Available A comunidade de macroinvertebrados bentônicos de um riacho de terceira ordem foi analisada em duas estações do ano, chuvosa e seca. Substratos artificiais foram amostrados semanalmente, ao longo de 56 dias para a coleta de macroinvertebrados, nas duas estações do ano. A composição da comunidade foi caracterizada por uma baixa diversidade, ou seja, presença de muitas espécies raras e poucas espécies abundantes nas duas estações do ano. Uma alta dominância de Chironomidae (Diptera nas duas estações, seguida de Baetidae (Ephemeroptera e Ancylidae (Mollusca, respectivamente nas estações chuvosa e seca, foi característico. Os resultados obtidos reforçam a grande importância de Chironomidae na comunidade bentônica de riachos e salientam a influência da sazonalidade sobre a estruturação destes organismos.The benthic macroinvertebrates community of a third order stream was studied during the wet and dry seasons. The community was analyzed using artificial substrates sampled weekly during 56 days in each season. The community composition was characterized by low species diversity, with high number of rare species and few abundant species for both seasons. A high dominance of Chinonomidae (Diptera for both seasons, followed by Baetidae (Ephemeroptera and Ancylidae (Mollusca, respectively for the wet and dry seasons, was found. The results reinforced the high importance of Chironomidae and the seasonal effect determining the stream benthic community structure.

  8. Macroinvertebrates as Indicators of Stream Health.

    Science.gov (United States)

    McDonald, Brook S.; And Others

    1991-01-01

    Describes Ohio's Scenic Rivers Monitoring Program that uses benthic macroinvertebrates, such as the stonefly, mayfly, and water penny beetle larva, as key indicators of water quality and stream health. Presents a three-category scheme for invertebrates based upon their tolerance to pollution. Students can collect samples of these organisms,…

  9. Deep-sea trace fossil and benthic foraminiferal assemblages across glacial Terminations 1, 2 and 4 at the "Shackleton Site" (IODP Expedition 339, Site U1385)

    Science.gov (United States)

    Rodríguez-Tovar, Francisco J.; Dorador, Javier; Grunert, Patrick; Hodell, David

    2015-10-01

    Numerous studies focused on the transitions between glacial and interglacial periods, the so-called terminations, due to the associated significant reorganizations of the ocean-atmosphere system. However, analyses combining macro- and micropaleontological information are near absent. In this research, an integrative study of trace fossils and benthic foraminiferal assemblages is conducted in order to improve the characterization of Terminations 1, 2 and 4, as revealing the response of the macro-and microbenthic habitats to the involved paleoenvironmental changes. For this purpose, selected cores from Site U1385 (IODP Expedition 339) located off the western Iberian Margin, have been studied. Changes in trace fossils and benthic foraminifera related to both long-term variations at the glacial/interglacial scale, and short-term millennial-scale climatic events. Food and oxygen availability have been identified as the main factors determining variations in the macro- and microbenthic community structure across glacial terminations in the context of changes in water mass distribution and productivity in the NE Atlantic. A deep-sea multi-tiered tracemaker community, consisting of biodeformational structures, Chondrites, ?Nereites, Palaeophycus, Planolites, Thalassinoides, and Zoophycos, suggest generally well-oxygenated bottom and pore-water conditions during interglacial as well as glacial intervals, with punctual decreases in oxygenation. Short-climatic events registered during Terminations 1, 2, and 4 induce a similar response of trace fossil and benthic foraminifera communities to the variable incidence of food and oxygen availability. Termination 1 shows a severe deterioration of oxic conditions and increasing food availability during the YD and HS 1, favoring appearance/dominance of Zoophycos, together with the lowest miliolid and the highest deep infaunal taxa abundances. Short-term climatic events (HS 11, IRE 10.1) associated with Terminations 2 and 4 are

  10. Evaluation of ecological quality in peri-urban rivers in Mexico City: a proposal for identifying and validating reference sites using benthic macroinvertebrates as indicators

    Directory of Open Access Journals (Sweden)

    Angela Caro-Borrero

    2015-08-01

    Full Text Available Conservation and management of aquatic ecosystems that are significantly influenced by urban activities requires the classification and establishment of potential reference sites. However, in Latin American countries, policies are not available that outlines the identification and evaluation of such sites. Therefore, this study represents a proposal for evaluating the ecological quality of peri-urban rivers in the conservation soil (CS areas/zones of Mexico City. The proposal accounts for the zone’s physicochemical, hydromorphological, and bacteriological characteristics along with its macroinvertebrate richness. Our evaluation was performed using a canonical correspondence analysis (CCA and indicator values (IndVal calculated for different species. River headwaters serve/work as a good physicochemical point for potential references sites. However, the hydromorphology of the CS has been gradually modified by numerous hydraulic alterations within the peri-urban zone. Using the CCA and IndVal, two types of sites were confirmed: sites in a good state of conservation and quality and sites modified by human activity, featuring lower discharge flow, poor quality hydromorphological values and Oligochaeta class organisms. At the sites featuring a good state of conservation and quality, higher hydromorphological values were positively correlated with discharge flow and certain macroinvertebrate taxa, including Nemouridae, Podonominae, Tanypodinae, Acarina, Baetis, Tipula, Antocha, Atopsyche, Glossosoma, Polycentropus, Hesperophylax and Limnephilus. In the sites modified by human activity, the genus Simulium was classified as a disturbance-tolerant organism. The river reach within the urban zone is basically an open-air drainage ditch. Evaluations of the ecological quality of the riparian zone were used to identify the most important hydromorphological qualities and discharge flow parameters and to select the most appropriate factors that should be

  11. Estimation and application of indicator values for common macroinvertebrate genera and families of the United States

    Science.gov (United States)

    Carlisle, D.M.; Meador, M.R.; Moulton, S.R., II; Ruhl, P.M.

    2007-01-01

    Tolerance of macroinvertebrate taxa to chemical and physical stressors is widely used in the analysis and interpretation of bioassessment data, but many estimates lack empirical bases. Our main objective was to estimate genus- and family-level indicator values (IVs) from a data set of macroinvertebrate communities, chemical, and physical stressors collected in a consistent manner throughout the United States. We then demonstrated an application of these IVs to detect alterations in benthic macroinvertebrate assemblages along gradients of urbanization in New England and Alabama. Principal components analysis (PCA) was used to create synthetic gradients of chemical stressors, for which genus- and family-level weighted averages (WAs) were calculated. Based on results of PCA, WAs were calculated for three synthetic gradients (ionic concentration, nutrient concentration, and dissolved oxygen/water temperature) and two uncorrelated physical variables (suspended sediment concentration and percent fines). Indicator values for each stress gradient were subsequently created by transforming WAs into ten ordinal ranks based on percentiles of values across all taxa. Mean IVs of genera and families were highly correlated to road density in Alabama and New England, and supported the conclusions of independent assessments of the chemical and physical stressors acting in each geographic area. Family IVs were nearly as responsive to urbanization as genus IVs. The limitations of widespread use of these IVs are discussed.

  12. Studies upon the structure and dynamics of the benthic macroinvertebrate communities from two habitats of The Ier River’s Channel (Bihor county, Romania)

    OpenAIRE

    iana CUPŞA; Magdolna BIRKAS; Ilie TELCEAN

    2009-01-01

    The aim of the present study was to describe the structure and dynamics of the macrozoobenthic communities on a sandy and muddy substrate from Ier Channel, in order to show the importance of the composition of the substratum in the macrozoobenthic community settlement. During the study period (May-October 2006) we identified 43 species and 884 individuals of benthic organisms, especially Gastropoda and insect larvae. The number of species and individuals exhibited high variability on the sand...

  13. The benthic marine assemblages of the estuarine and shallow marine Upper Burdigalian deposits of the Korneuburg Basin in Lower Austria

    Science.gov (United States)

    Hengst, Babette; Zuschin, Martin; Harzhauser, Mathias; Mandic, Oleg; Roetzel, Reinhard

    2010-05-01

    In the course of highway constructions (Wiener Außenring-Schnellstraße (S1)) a detailed sedimentological transect of 1.8 km length was logged in deposits of the Central Paratethys near the village of Stetten, N of Korneuburg in Lower Austria. A total of 324 sediment- and 118 molluscan samples was studied. The siliciclastic succession consists of pelitic and sandy sediments and sandstones and is rich in fossils. The fossil remains consist of sponges, corals, serpulids, molluscs, balanids, echinoderms, fish and micromammals. Quantitatively the molluscs dominate and have been studied in detail. 139 species were determined from more than 11,000 shells. Two gastropod species, Agapilia pachii und Granulolabium bicinctum make up more than 53% of the assemblage. Another 11 species (Nassarius edlaueri, Bittium spina, Loripes dujardini, Hydrobia spp., Paphia subcarinata, Cyllenina ternodosa, Turritella gradata, Corbula gibba, Cerastoderma praeplicata, Striarca lactea, Sandbergeria perpusilla) each contributes more than 1% to the total molluscan composition, but all other 126 species are quantitatively unimportant. A conspicuous alternation between intertidal and shallow subtidal mollusc associations is evident. The intertidal is dominated by the superabundant Agapilia pachii and Granulolabium plicatum, whereas the heavily bioturbated fully marine subtidal is characterized by a more diverse assemblage including Turritella gradata, Nassarius edlaueri, Anadara diluvii and various venerids. Additionally, layers with large fragments of Crassostrea and thin coal deposits with Terebralia bidentata are quite abundant in the section. Washed in land snails (e.g., Planorbidae) and river snails (Melanopsidae) occur occasionally. This faunal composition, along with its typical alternation points to a vivid dynamic within this Lower Miocene, subtropical ecosystem in the paleo-estuary of the southern Korneuburg basin.

  14. Temporal changes in taxonomic and functional diversity of fish assemblages downstream from mountaintop mining

    Science.gov (United States)

    Hitt, Nathaniel P.; Chambers, Douglas B.

    2014-01-01

    Mountaintop mining (MTM) affects chemical, physical, and hydrological properties of receiving streams, but the long-term consequences for fish-assemblage structure and function are poorly understood. We sampled stream fish assemblages using electrofishing techniques in MTM exposure sites and reference sites within the Guyandotte River basin, USA, during 2010–2011. We calculated indices of taxonomic diversity (species richness, abundance, Shannon diversity) and functional diversity (functional richness, functional evenness, functional divergence) to compare exposure and reference assemblages between seasons (spring and autumn) and across years (1999–2011). We based temporal comparisons on 2 sites that were sampled during 1999–2001 by Stauffer and Ferreri (2002). Exposure assemblages had lower taxonomic and functional diversity than reference assemblages or simulated assemblages that accounted for random variation. Differences in taxonomic composition between reference and exposure assemblages were associated with conductivity and aqueous Se concentrations. Exposure assemblages had fewer species, lower abundances, and less biomass than reference assemblages across years and seasons. Green Sunfish (Lepomis cyanellus) and Creek Chub (Semotilus atromaculatus) became numerically dominant in exposure assemblages over time because of their persistence and losses of other taxa. In contrast, species richness increased over time in reference assemblages, a result that may indicate recovery from drought. Mean individual biomass increased as fish density decreased and most obligate invertivores were apparently extirpated at MTM exposure sites. Effects of MTM were not related to physical-habitat conditions but were associated with water-quality variables, which may limit quality and availability of benthic macroinvertebrate prey. Simulations revealed effects of MTM that could not be attributed to random variation in fish assemblage structure.

  15. Cold seep and oxygen minimum zone associated sources of margin heterogeneity affect benthic assemblages, diversity and nutrition at the Cascadian margin (NE Pacific Ocean)

    Science.gov (United States)

    Guilini, Katja; Levin, Lisa A.; Vanreusel, Ann

    2012-04-01

    Hydrate Ridge (HR), located on the northeastern Pacific margin off Oregon, is characterized by the presence of outcropping hydrates and active methane seepage. Additionally, permanent low oxygen conditions overlay the benthic realm. This study evaluated the relative influence of both seepage and oxygen minima as sources of habitat heterogeneity and potential stress-inducing features on the bathyal metazoan benthos (primarily nematodes) at three different seep and non-seep HR locations, exposed to decreasing bottom-water oxygen concentrations with increasing water depth. The nematode seep communities at HR exhibited low diversity with dominance of only one or two genera (Daptonema and Metadesmolaimus), elevated average individual biomass and δ13C evidence for strong dependance on chemosynthesis-derived carbon, resembling deep-sea seeps worldwide. Although the HR seep habitats harbored a distinct nematode community like in other known seep communities, they differed from deep-sea seeps in well-oxygenated waters based on that they shared the dominant genera with the surrounding non-seep sediments overlain by oxygen-deficient bottom water. The homogenizing effect of the oxygen minimum zone on the seep nematode assemblages and surrounding sediments was constant with increasing water depth and concomitant greater oxygen-deficiency, resulting in a loss of habitat heterogeneity.

  16. Assessing the influence of source distance and hydroecoregion on the invertebrate assemblage similarity in central Italy streams

    Directory of Open Access Journals (Sweden)

    Traversetti L.

    2014-04-01

    Full Text Available Increasing the river habitat safeguard level is one of the main actions proposed by the European Water Framework Directive in the field of biomonitoring. To do so, watercourses within the same hydroecoregions (that is, homogeneous areas based on climate, geology and topography ought to be compared. In addition, the source distance was thought to play an important role in comparing rivers and then planning monitoring activities. The purpose of this study was to evaluate if both hydroecoregion and source distance affect the response (in terms of taxa assemblage of one of the most used group in the river monitoring activities: the benthic macroinvertebrate. Here we proposed the comparative influence of hydroecoregion and source distance on the invertebrate assemblage in Mediterranean rivers of central Italy. Our statistical outputs highlighted how macroinvertebrate differed for both hydroecoregions and source distance ranks. In particular, no differences were found among sites of different (1 source distance ranks and (2 hydroecoregion (that is, when this two descriptors were analyzed separately, while the highest difference in the macroinvertebrate assemblage was observed between the same source distance ranks of different hydroecoregions. Our results showed how the use of both hydroecoregion and source distance should be considered for planning monitoring activities to properly manage rivers and water resources.

  17. The response of benthic macroinvertebrate and fish assemblages to human impact along the lower stretch of the rivers Morava and Dyje (Danube basin, Czech Republic)

    Czech Academy of Sciences Publication Activity Database

    Adámek, Zdeněk; Zahrádková, S.; Jurajda, Pavel; Bernardová, I.; Jurajdová, Zdenka; Janáč, Michal; Němejcová, D.

    2013-01-01

    Roč. 71, č. 3 (2013), s. 93-115. ISSN 1330-061X R&D Projects: GA ČR GBP505/12/G112 Institutional support: RVO:68081766 Keywords : Macrozoobenthos * Fish * Diversity * River pollution * River regulation * Joint Danube Survey Subject RIV: EG - Zoology http:// ribarstvo .agr.hr/volumes.php?lang=en&search=Article%3A656

  18. Environmental impact of bleufin tuna aquaculture on benthic assemblages in the western coast of Baja California, Mexico

    Science.gov (United States)

    Diaz-Castaneda, V.

    2013-05-01

    Sea-cage farming results in a constant rain of organic waste onto the surrounding benthos. In Baja California there is growing concern over the effects of sea-cages on the local environment: sediment chemistry and benthic communities. Samples were taken in 18 stations using a Van veen grab (0.1 m2) in Bahía Salsipuedes, Baja California in 2003, 2004, 2006 and 2008. Organisms belonging to 7 Phyla were collected: Polychaeta, Mollusca, Crustacea, Echinodermata, Cnidaria, Sipuncula and Bryozoa. Polychaetes were the dominant group followed by crustaceans and mollusks. Polychaetes were represented by 37 families and 157 species. Best represented families were Paraonidae, Cirratulidae, Spionidae, Glyceridae and Maldanidae. This study shows that in the NW area of the bay organic carbon (2.54%) and organic nitrogen (0.95%) are being accumulated (higher concentrations and lower Eh values) and smaller opportunistic species are increasing rapidly near the tuna pens. It is crucial to maintain "healthy" macrofaunal populations in order to enhance decomposition of organic matter and to prevent its excessive accumulation. The most abundant polychaete species were Aphelochaeta multifinis, Mediomastus ambiseta, Prionospio steenstrupi Spiophanes bombyx, Apoprionospio pygnaea, Paraonella sp, Monticellina sp, Aricidea (Allia) ramosa, Spiophanes bombyx and Levinsenia gracilis. The dominant trophic groups were deposit-feeders and carnivores. The buildup of organic matter on the seafloor has attracted scavenger species particularly peracarid crustaceans. Non-metric multidimensional scaling (MDS) separated stations depending of the distance to the tuna pens.

  19. Assessing the performance of macroinvertebrate metrics in the Challhuaco-Ñireco System (Northern Patagonia, Argentina

    Directory of Open Access Journals (Sweden)

    Melina Mauad

    2015-09-01

    Full Text Available ABSTRACT Seven sites were examined in the Challhuaco-Ñireco system, located in the reserve of the Nahuel Huapi National Park, however part of the catchment is urbanized, being San Carlos de Bariloche (150,000 inhabitants placed in the lower part of the basin. Physico-chemical variables were measured and benthic macroinvertebrates were collected during three consecutive years at seven sites from the headwater to the river outlet. Sites near the source of the river were characterised by Plecoptera, Ephemeroptera, Trichoptera and Diptera, whereas sites close to the river mouth were dominated by Diptera, Oligochaeta and Mollusca. Regarding functional feeding groups, collector-gatherers were dominant at all sites and this pattern was consistent among years. Ordination Analysis (RDA revealed that species assemblages distribution responded to the climatic and topographic gradient (temperature and elevation, but also were associated with variables related to human impact (conductivity, nitrate and phosphate contents. Species assemblages at headwaters were mostly represented by sensitive insects, whereas tolerant taxa such as Tubificidae, Lumbriculidae, Chironomidae and crustacean Aegla sp. were dominant at urbanised sites. Regarding macroinvertebrate metrics employed, total richness, EPT taxa, Shannon diversity index and Biotic Monitoring Patagonian Stream index resulted fairly consistent and evidenced different levels of disturbances at the stream, meaning that this measures are suitable for evaluation of the status of Patagonian mountain streams.

  20. Comparison of benthic macroinvertebrate indices for the assessment of the impact of acid mine drainage on an Irish river below an abandoned Cu-S mine

    International Nuclear Information System (INIS)

    A range of macroinvertebrate indices were compared to assess the most appropriate metric for the assessment of acid mine drainage (AMD) in a low alkalinity, highly erosional river in south-east Ireland. Differences were found in the ability of indices to discriminate AMD impact with the Brillouin, BMWP score, Margalef and Shannon Indices the most precise. Taxon richness was also strongly correlated with AMD indicator parameters (e.g. pH alkalinity, sulphate, Zn and Fe) at impacted sites being an equally reliable metric. The response of the community structure to AMD in this river does not fulfil the optimum criteria for either diversity or biological indices, which may explain the variation in the success of different indices seen in this and other studies. The development of indices that model the expected community response to AMD more accurately or are based on the response of indicator species to AMD pollutants are required. - Several indices were suitable for AMD impact assessment, although due to AMD and receiving water variability no single index may be universally reliable

  1. Seasonal mercury concentrations and δ15N and δ13C values of benthic macroinvertebrates and sediments from a historically polluted estuary in south central Chile

    International Nuclear Information System (INIS)

    The Lenga Estuary is one of the most industrialized sites in south central Chile where the historic operation of chlor-alkali plants resulted in large quantities of mercury (Hg) being deposited into the estuary. This historical contamination may still represent a risk to the biota in the estuary. To investigate this four macroinvertebrates, Neotrypaea uncinata (ghostshrimp), Elminius kingii (barnacle), Hemigrapsus crenulatus (shore crab) and Perinereis gualpensis (ragworm) were collected seasonally from three different sites in the Lenga Estuary and one in a reference estuary (Tubul Estuary), and analyzed for Hg and stable isotopes (δ15N and δ13C). Mercury concentrations in Lenga sediments ranged from 0.4 ± 0.1 to 13 ± 3 mg/kg, while those in Tubul sediments ranged from 0.02 ± 0.01 to 0.07 ± 0.09 mg/kg. Total Hg concentrations of invertebrates were significantly different between estuaries (p 0.05). In contrast, organic Hg concentrations were different by species and season with shore crab muscle tissues exhibiting the greatest percent difference. Site-specific relationships demonstrated that total Hg concentrations in ragworm best reflected the total Hg sediment mercury concentrations. Signatures of δ13C were correlated to the organic Hg % rather than total Hg. This suggests that organic Hg concentrations in these species were related to the carbon sources. -- Highlights: ► Hg in sediments and biota from Lenga Estuary were elevated compared to nearby estuary. ► Invertebrates showed interspecific and seasonal differences in terms of organic Hg %. ► Total Hg levels in the ragworm best reflect Hg sediment gradient in Lenga Estuary. ► Interspecific variation in δ13C signatures indicated different feeding modes. ► Organic forms of Hg in invertebrates were mainly related to the carbon sources.

  2. Influence of stream habitat and land use on benthic macroinvertebrate indicators of stream quality of selected above-tidal streams in the Houston-Galveston Area Council service area, Texas, 1997-98

    Science.gov (United States)

    Moring, J. Bruce

    2001-01-01

    During 1997?98, the U.S. Geological Survey, in cooperation with the Houston-Galveston Area Council, collected stream-habitat and benthic macroinvertebrate data for 31 reaches on above-tidal streams in the Council service area near Houston, Texas. Stream-habitat, land-use and population, and benthic aquatic insect metrics were determined for the 31 reaches. Statistical analyses were used to determine the stream-habitat, land-use and population, and aquatic insect variables that are strongly intercorrelated and that explain the greatest amount of variation between the reaches. Comparison of stream-habitat and biological integrity scores computed for each of the 31 reaches indicated (1) reaches generally had larger stream-habitat integrity scores in drainage areas that were heavily forested and had fewer people per square mile, (2) larger biological integrity scores were significantly correlated with larger stream-habitat integrity scores, and (3) urban reaches generally had more simplified stream-habitat conditions and smaller biological integrity scores. Seven reaches in the study area were selected as reference reaches on the basis of high stream-habitat integrity and high biological integrity. The reference-reaches median biological integrity score was equaled or exceeded by three reaches (one on Spring Creek and two on Cypress Creek) that are on the State of Texas 303(d) list of threatened or impaired waters with respect to aquatic life. This indicates that direct measures of biological integrity could be used to supplement surrogate-based designations of biological integrity such as the State list. A statistically significant multiple-regression model was developed that uses independent variables that can be obtained without field-intensive studies to predict the biological integrity score for a reach. The deviation from the model?s predicted score with the score based on biological sampling can be used to interpret the degree of biological impairment in a reach

  3. Construction of habitat suitability models(HSMs)for benthic macroinvertebrate and their applications to instream environmental flows:A case study in Xiangxi River of Three Gorges Reservior region,China

    Institute of Scientific and Technical Information of China (English)

    Fengqing Li; Qinghua Cai; Xiaocheng Fu; Jiankang Liu

    2009-01-01

    Based on a long-term ecological monitoring,the present study chose the most dominant benthic macroinvertebrate(Baetis spp.)as tar-get organisms in Xiangxi River,built the habitat suitability models(HSMs)for water depth,current velocity and substrate,respectively,which is the first aquatic organisms model for habitat suitability in the Chinese Mainland with a long-term consecutive in situ measurement.In order to protect the biointegrity and function of the river ecosystem,the theory system of instream environmental flow should be categorized into three hierarchies, namely minimum required instream flow(hydrological level),minimum instream environmental flow(bio-species level),and optimum instream environmental flow(ecosystem level).These three hierarchies of instream environmental flow models were then constructed with the hydropogical and seighted usable area(WUA)method.The results show that the minimum required instream flow of Yiangxi River calculated by the Tennant method(10% of the mean annual flow)was 0.615m3s-1;the minimum instream environmental flow accounted for 19.22% of the mean annual flow(namely 1.182m3s-1),which was the damaged river channel flow in the dry season;and 42.91% of the mean annual flow(namely 2.639m3s-1)should be viewed as the optimum instream environmental flow in order to protect the health of the river ecosystem,maintain the instream biodiversity,and reduce the impact of small hydropower stations nearby the Xiangxi River.We recommend that the hydrological and biological methods can help establish better instream environmental flow models and design best management practices for use in the small hydropower station project.

  4. Concentrations of metals in water, sediment, biofilm, benthic macroinvertebrates, and fish in the boulder river watershed, Montana, and the role of colloids in metal uptake

    Science.gov (United States)

    Farag, A.M.; Nimick, D.A.; Kimball, B.A.; Church, S.E.; Harper, D.D.; Brumbaugh, W.G.

    2007-01-01

    To characterize the partitioning of metals in a stream ecosystem, concentrations of trace metals including As, Cd, Cu, Pb, and Zn were measured in water, colloids, sediment, biofilm (also referred to as aufwuchs), macroinvertebrates, and fish collected from the Boulder River watershed, Montana. Median concentrations of Cd, Cu, and Zn in water throughout the watershed exceeded the U.S. EPA acute and chronic criteria for protection of aquatic life. Concentrations of As, Cd, Cu, Pb, and Zn in sediment were sufficient in the tributaries to cause invertebrate toxicity. The concentrations of As, Cu, Cd, Pb, and Zn in invertebrates from lower Cataract Creek (63, 339, 59, 34, and 2,410 ??g/g dry wt, respectively) were greater than the concentrations in invertebrates from the Clark Fork River watershed, Montana (19, 174, 2.3, 15, and 648 ??g/g, respectively), that were associated with reduced survival, growth, and health of cutthroat trout fed diets composed of those invertebrates. Colloids and biofilm seem to play a critical role in the pathway of metals into the food chain and concentrations of As, Cu, Pb, and Zn in these two components are significantly correlated. We suggest that transfer of metals associated with Fe colloids to biological components of biofilm is an important pathway where metals associated with abiotic components are first available to biotic components. The significant correlations suggest that Cd, Cu, and Zn may move independently to biota (biofilm, invertebrates, or fish tissues) from water and sediment. The possibility exists that Cd, Cu, and Zn concentrations increase in fish tissues as a result of direct contact with water and sediment and indirect exposure through the food chain. However, uptake through the food chain to fish may be more important for As. Although As concentrations in colloids and biofilm were significantly correlated with As water concentrations, As concentrations in fish tissues were not correlated with water. The pathway for

  5. Efeito de metais Cobre (Cu e Zinco (Zn sobre a comunidade de macroinvertebrados bentônicos em riachos do sul do Brasil - DOI: 10.4025/actascibiolsci.v30i3.677 The effect of metals (Cu and Zn on the benthic macroinvertebrate community in streams in southern Brazil - DOI: 10.4025/actascibiolsci.v30i3.677

    Directory of Open Access Journals (Sweden)

    Luiz Ubiratan Hepp

    2008-10-01

    Full Text Available O objetivo deste estudo foi avaliar os efeitos de metais (Cu e Zn sobre a comunidade de macroinverterados bentônicos. Foram amostrados, trimestralmente, entre setembro de 2006 e junho de 2007, organismos e água em oito trechos de riachos de duas bacias hidrográficas influenciadas por urbanização e agricultura. Foram estimados os valores de densidade de organismos, riqueza taxonômica e diversidade de Shannon. Para avaliação dos dados, foram utilizados testes de variância e regressão linear simples. Os resultados demonstraram variabilidade das concentrações dos metais e da macrofauna entre as estações do ano e riachos estudados. O metal Cobre (Cu apresentou influência apenas sobre a densidade Chironomidae e o metal Zinco (Zn apresentou efeito sobre a densidade total da macrofauna bentônica e de Chironomidae. Nenhum dos metais apresentou efeitos sobre a riqueza e diversidade de macroinvertebrados. Os resultados indicam potencial bioindicador da comunidade bentônica na avaliação da qualidade integrada do ambiente.The aim of this study was to evaluate the effect of metals (Cu and Zn on the benthic macroinvertebrate community. The organisms and water were collected quarterly between September 2006 and June 2007, in eight sites in streams of two hydrographic basins, influenced by urbanization and agriculture. The values of organism density, taxonomic richness and the Shannon diversity index were calculated. For data evaluation, tests of variance and simple linear regression were used. The results showed variability in the metal concentration and benthic community among seasons and studied streams. Cu showed influence only on Chironomidae density. Zn demonstrated effect on the benthic community and Chironomidae density. None of the metals presented effect on the macroinvertebrate richness and diversity. The results indicate a bioindicator potential of the benthic community in the evaluation of integral quality of the environment.

  6. Efficiency of Different Sampling Tools for Aquatic Macroinvertebrate Collections in Malaysian Streams

    OpenAIRE

    Ghani, Wan Mohd Hafezul Wan Abdul; Rawi, Che Salmah Md; Hamid, Suhaila Abd; Al-Shami, Salman Abdo

    2016-01-01

    This study analyses the sampling performance of three benthic sampling tools commonly used to collect freshwater macroinvertebrates. Efficiency of qualitative D-frame and square aquatic nets were compared to a quantitative Surber sampler in tropical Malaysian streams. The abundance and diversity of macroinvertebrates collected using each tool evaluated along with their relative variations (RVs). Each tool was used to sample macroinvertebrates from three streams draining different areas: a veg...

  7. Altered performance of white sucker populations in the Manitouwadge chain of lakes is associated with changes in benthic macroinvertebrate communities as a result of copper and zinc contamination

    Energy Technology Data Exchange (ETDEWEB)

    Munkittrick, K.R.; Miller, P.A.; Barton, D.R.; Dixon, D.G. (University of Waterloo, Ontario (Canada))

    1991-06-01

    White sucker (Catostomus commersoni) collected from the Manitouwadge chain of lakes show a lower growth rate and fecundity in lakes contaminated with copper and zinc from a mixed metal mine. This study evaluated whether the changes in performance of the fish were related to direct impacts of the metals or indirect impacts associated with changes in food availability. Concentrations of metals in the water and sediment of lakes in the Manitouwadge chain were elevated, relative to reference sites. The concentrations of Cu and Zn in the digesta of white sucker were significantly higher, as were the levels of both Cu and Zn in liver, kidney, and gill tissue. Muscle and spleen levels of Cu and Zn were significantly lower or not different from controls. Tissue levels were within the homeostatic range for Cu and Zn. However, the total density of invertebrates varied from greater than 25,000 m-2 at control sites to less than 13,000 m-2 at contaminated sites, and the number of genera recorded was more than 50% lower in shallow water samples. There was almost a complete absence of several invertebrate taxa at contaminated sites, including Plecoptera, Ephemeroptera, Odonata, Trichoptera, Amphipoda, and Unionidae. Diptera accounted for 78 to 96% of the total numbers of individuals at metal-contaminated sites as compared with 40 to 75% at the control sites. An analysis of white sucker stomach contents showed that the contents closely reflected the benthic composition observed in the natural substrate. Changes in food availability and feeding activity were correlated with previous changes documented in the growth, fecundity, and lipid levels of white sucker.

  8. Macroinvertebrate diversity in the karst Jadro River (Croatia

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    Rađa Biljana

    2008-01-01

    Full Text Available This paper presents the results of 10 years of investigation of the aquatic macroinvertebrate fauna along the karst Jadro River. The Jadro is a typical karst river. Benthic macroinvertebrates were collected along the river at 15 sites by standard methods of sampling, in addition to which several physicochemical parameters were also determined. Based on qualitative and quantitative composition of the macroinvertebrate fauna, correspondence analysis divided the river course into three sections: upstream, midcourse, and downstream. Forty-three taxa were recorded. Results of saprobiological analysis based on macrozoobenthos indicate that water of the Jadro River belongs to quality classes I and II.

  9. Riparian leaf litter processing by benthic macroinvertebrates in a woodland stream of central Chile Procesamiento de detritus ripariano por macroinvertebrados bentónicos en un estero boscoso de Chile central

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    CLAUDIO VALDOVINOS

    2001-06-01

    Full Text Available Leaf litter input from riparian landscapes has been identified as both a major energy flow to stream ecosystems and as a food source for stream macroinvertebrates. In riparian landscapes of woodland streams of central Chile, the native deciduous hardwoods are being artificially replaced by exotic coniferous trees at a large spatial scale. It is suggested that this process has a significant impact on the stream communities of central Chile. Today, exotic plantations occur throughout central Chile, with Pinus radiata (D. Don (Monterrey pine accounting for about 80 % of the more than 1,800,000 ha of exotic forests. The objective of this paper was to analyze the effect of the litter beds of a dominant native species (Nothofagus pumilio and an exotic species (P. radiata on the detritus processing carried out by benthic macroinvertebrates, in an experimental catchment of central Chile (Rucúe Creek; 36° 26'00" S, 71° 35'40" W. Results revealed that processing rates of native leaf packs are higher than rates of coniferous leaf packs, suggesting that the replacement of the native hardwoods by exotic coniferous riparian flora has an important impact on the stream energy flow in central Chile. The decay rate coefficients (k were 0.0072 for N. pumilio, and 0.0027 for P. radiata. The greater abundance and biomass of shredders per gram of leaf pack of native Nothofagus would explain the differences in leaf processing rates, especially through the activity of two Plecoptera Gripopterygidae, Limnoperla jaffueli and Antarctoperla michaelseniLa entrada de detritus foliar procedente de áreas riparianas ha sido reconocido como un componente importante en la energética de ecosistemas fluviales y como fuente de alimento de macroinvertebrados acuáticos. En áreas riparianas de esteros boscosos de Chile central los componentes nativos caducifolios están siendo artificialmente reemplazados a gran escala por coníferas exóticas, sugiriendo que este proceso tiene

  10. Temporal variability in macroinvertebrates diversity patterns and their relation with environmental factors

    OpenAIRE

    MOHAMMAD HASAN GERAMI; RAHMAN PATIMAR; HOSSEIN NEGARESTAN; HOJJATOLLAH JAFARIAN; MOHAMMAD SEDDIQ MORTAZAVI

    2016-01-01

    Abstract. Gerami MH, Patimar R, Negarestan H, Jafarian H, Mortazavi MS. 2015. Temporal variability in macroinvertebrates diversity patterns and their relation with environmental factors. Biodiversitas 17: 36-43. Seasonal changes are the most important factor in temporal variability of macroinvertebrates communities in marine benthic zone. Realizing the pattern of these changes are the key attributes to maintain benthic resources. For this purpose this study aimed to investigate temporal varia...

  11. The benthic macroinvertebrate fauna of highland streams in southern Brazil: composition, diversity and structure Fauna de macro-invertebrados bentônicos de rios de montanha no sul do Brasil: composição, diversidade e estrutura

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    Ludwig Buckup

    2007-06-01

    Full Text Available Benthic macroinvertebrate in four rivers, three in the Pelotas River basin (Divisa, Marco and Silveira rivers, in the headwaters of the Uruguai River and one in the Taquari-Antas system (Antas River, a tributary in the Guaíba basin, in the state of Rio Grande do Sul, were identified. Two samples were collected in summer, autumn and spring, with one replicate in each river. The total of 28,961 specimens included members of Platyhelminthes, Annelida, Acarina, Insecta, Crustacea and Mollusca. The Silveira and Marco rivers showed significant differences in the indices of Shannon-Weaver (H’, Simpson’s Reciprocal (1/D, Margalef (DMg and Equitability (E. The Silveira River showed the highest means of diversity and the EPT index (Ephemeroptera, Plecoptera, Trichoptera. Comparison among the diversity indices, considered individually, were insufficient to show differences in community structure, for the purpose of ecological characterization of the rivers. The EPT values characterized the Divisa River as having the highest abundance (73%, followed by the Marco (71%, Antas (48% and Silveira (36%. These results suggest that the Silveira River is subject to moderate environmental stress, from human impact, although it showed the highest diversity of the major macrobenthic groups.Os macro-invertebrados bentônicos que ocorrem em quatro rios, três pertencentes à bacia do Rio Pelotas (Rios Divisa, Marco e Silveira nas cabeceiras do Rio Uruguai e um ao sistema Taquari-Antas (Rio Antas, tributário da bacia do Guaíba, no Estado do Rio Grande do Sul, foram identificados. Duas amostras foram coletadas no verão, outono e primavera, com uma réplica em cada rio. Foram coletados 28961 espécimes de macro-invertebrados compreendendo Platyhelminthes, Annelida, Acarina, Insecta, Crustacea e Mollusca. Na comparação entre os rios, Silveira e Marco mostraram diferenças significativas nos índices de Shannon-Weaver (H’, no Recíproco de Simpson (1/D, de

  12. Effects of carbofuran and metsulfuron-methyl on the benthic macroinvertebrate community in flooded ricefields Efeito do carbofurano e metsulfuron-methyl sobre a comunidade de macroinvertebrados bentônicos de lavoura de arroz irrigado

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    Joele Baumart

    2011-06-01

    Full Text Available AIM: This study evaluated the effect of the insecticide carbofuran and the herbicide metsulfuron-methyl on the abundance and diversity of benthic macroinvertebrates in a paddy ricefield. METHODS: To achieve this goal, two pesticide treatments [the insecticide carbofuran (IC and the herbicide metsulfuron-methyl (HM] and a control (Co treatment with no added pesticide were established in an experimental area of the Plant Science Department of the Federal University of Santa Maria. Soil samples were collected in triplicate from each treatment 30 days before and 1, 10, and 51 days after the pesticide application, for macrofauna identification. RESULTS: Among the 21 taxa identified, Trichoceridae was present only in Co, Hydroptilidae was recorded only in IC, and Corixidae in HM. In Co, the most abundant group was Annelida, while in IC and HM Diptera (Chironomidae was dominant. Significant differences were observed between Co and IC, in the density of Odontoceridae (Control>IC and Hydrophilidae (ControlHM and Hirudinea (ControlOBJETIVO: O objetivo desse estudo foi avaliar o efeito do inseticida carbofurano e do herbicida metsulfuron-methyl na abundância e diversidade de macroinvertebrados bentônicos em campo de arroz irrigado. MÉTODOS: Para isto, dois tratamentos com agrotóxicos [o inseticida carbofurano (IC e o herbicida metsulfuron-methyl (HM] e um controle (Co, tratamento sem pesticida, foram aplicados em uma área experimental no Departamento de Fitotecnia da Universidade Federal de Santa Maria. Amostras de solo foram coletadas em triplicatas em cada tratamento 30 dias antes (DBA e 1, 10 e 51 dias após a aplicação dos pesticidas, posteriormente a macrofauna foi identificada. RESULTADOS: Vinte e um (21 taxa foram identificados, entre esses Trichoceridae esteve presente apenas em Co, enquanto que Hydroptilidae foi coletado apenas em IC, e Corixidae em HM. Em Co e IC, o grupo mais abundante foi Annelida, e em HM foi Diptera (Chironomidae que

  13. Using Regional Distribution of Estuarine and Coastal Benthic Invertebrates to Calibrate Benthic Indices of Ecological Condition

    Science.gov (United States)

    The biogeography of marine benthic macroinvertebrates of the U.S. Atlantic coast from Delaware Bay north to Passamaquoddy Bay, Maine, was studied to define physical-chemical factors affecting broad taxa distributions and provide information needed to calibrate benthic indices of ...

  14. Evaluation of alternative macroinvertebrate sampling techniques for use in a new tropical freshwater bioassessment scheme

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    Isabel Eleanor Moore

    2015-06-01

    Full Text Available Aim: The study aimed to determine the effectiveness of benthic macroinvertebrate dredge net sampling procedures as an alternative method to kick net sampling in tropical freshwater systems, specifically as an evaluation of sampling methods used in the Zambian Invertebrate Scoring System (ZISS river bioassessment scheme. Tropical freshwater ecosystems are sometimes dangerous or inaccessible to sampling teams using traditional kick-sampling methods, so identifying an alternative procedure that produces similar results is necessary in order to collect data from a wide variety of habitats.MethodsBoth kick and dredge nets were used to collect macroinvertebrate samples at 16 riverine sites in Zambia, ranging from backwaters and floodplain lagoons to fast flowing streams and rivers. The data were used to calculate ZISS, diversity (S: number of taxa present, and Average Score Per Taxon (ASPT scores per site, using the two sampling methods to compare their sampling effectiveness. Environmental parameters, namely pH, conductivity, underwater photosynthetically active radiation (PAR, temperature, alkalinity, flow, and altitude, were also recorded and used in statistical analysis. Invertebrate communities present at the sample sites were determined using multivariate procedures.ResultsAnalysis of the invertebrate community and environmental data suggested that the testing exercise was undertaken in four distinct macroinvertebrate community types, supporting at least two quite different macroinvertebrate assemblages, and showing significant differences in habitat conditions. Significant correlations were found for all three bioassessment score variables between results acquired using the two methods, with dredge-sampling normally producing lower scores than did the kick net procedures. Linear regression models were produced in order to correct each biological variable score collected by a dredge net to a score similar to that of one collected by kick net

  15. Spatial heterogeneity of benthic community assemblages with an emphasis on reef algae at French Frigate Shoals, Northwestern Hawai`ian Islands

    Science.gov (United States)

    Vroom, Peter S.; Page, Kimberly N.; Peyton, Kimberly A.; Kukea-Shultz, J. Kanekoa

    2005-12-01

    Reefs in tropical atoll systems have historically been described on a geomorphic basis, and segregated into loosely defined fore-reef, back-reef, and lagoonal reef zones. However, recent oceanographic monitoring data have shown that physical factors within a single geomorphic zone can vary significantly, calling into question whether benthic communities within a single zone are biologically similar. To determine the amount of benthic variability that may occur in a geomorphic zone, percent cover of benthic organisms was determined at the species level for 28 sites in three geomorphic zones at French Frigate Shoals, Northwestern Hawai‘ian Islands. Multivariate statistical analyses found most windward fore-reef and back-reef sites to be statistically similar, but considerable variation to exist among sites within calmer lagoonal areas. Surveys revealed macroalgae to dominate over scleractinian coral species at the majority of sites in this healthy, subtropical reef system, although select lagoonal areas were dominated by dense coral communities.

  16. Impact of macroalgal blooms and wader predation on intertidal macroinvertebrates: experimental evidence from the Mondego estuary (Portugal)

    OpenAIRE

    Lopes, Ricardo J; Pardal, Miguel A.; Marques, João C.

    2000-01-01

    The effect of macroalgal blooms and predation by wading on benthic macroinvertebrates was examined in the Mondego estuary, Portugal, during spring 1997. Introduced macroalgal cover and exclusion of predators were used to examine changes in density of macroinvertebrates using univariate and multivariate analyses. There was no evidence of changes in numbers of macroinvertebrates due to predation. Macroalgae were, however, responsible for a decrease in abundance of the worms Amage adspersa (Grub...

  17. Influence of bauxite tailings on the structure of the benthic macroinvertebrate community in an Amazonian Lake (Lago Batata, Pará - Brazil Influência do rejeito de bauxita sobre a estrutura da comunidade de macroinvertebrados bentônicos em um lago amazônico (Lago Batata, Pará, Brasil

    Directory of Open Access Journals (Sweden)

    J. J. L. FONSECA

    1999-08-01

    Full Text Available This research was developed between 1993 and 1996, aiming to study the structure of the benthic macroinvertebrate community, relating it to some abiotic variables, in an amazonian lake (lago Batata, that received for ten years a great amount of bauxite tailings. The benthic macroinvertebrates were collected with a core and the abiotic variables that were measured were: dissolved oxygen, suspended material, depth, transparency (secchi disc, temperature of the water column and total nitrogen, available phosphorus and organic matter in the sediment. With the use of a Principal Components Analysis (PCA, we were able to show that the sampling sites differed regarding the abiotic variables, especially total-N, available-P and organic matter in the sediment, all of which were found in greater concentrations in the natural areas. The PCA concerning the benthic macroinvertebrate community also distinguished the natural sites from the impacted one. The impacted site was positively grouped with the Ephemeroptera (Campsurus sp. and the natural sites were grouped together with the Chironomidae, Chaoboridae, Oligochaeta and Bivalvia. The results achieved in this research made clear that the sites under influence of the bauxite tailings had alterations of their abiotic characteristics and of their benthic macroinvertebrate structure.Esta pesquisa foi desenvolvida entre 1993 e 1996 com o objetivo de estudar a estrutura da comunidade de macroinvertebrados bentônicos, relacionando-a a algumas variáveis abióticas, em um lago amazônico (lago Batata, que recebeu durante dez anos rejeito de bauxita. Os macroinvertebrados bentônicos foram coletados com um coletor tipo core e as variáveis abióticas medidas foram: oxigênio dissolvido, material em suspensão, profundidade, transparência (disco de secchi, temperatura da coluna d’água e nitrogênio total, fósforo disponível e matéria orgânica do sedimento. A partir da aplicação da Análise de Componentes

  18. Zoogeografía de macroinvertebrados bentónicos de la costa de Chile: contribución para la conservación marina Zoogeography of benthic macroinvertebrates of the Chilean coast: contribution for marine conservation

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    DOMINGO A. LANCELLOTTI

    2000-03-01

    Full Text Available La diversidad de macroinvertebrados marinos ha recibido una atención creciente, no obstante, con un escaso tratamiento en el contexto biogeográfico. Este estudio analiza los registros de 1.601 especies de macroinvertebrados bentónicos pertenecientes a: Demospongiae, Anthozoa, Polychaeta, Mollusca, Crustacea, Echinodermata y Ascideacea, agrupados en 10 zonas y tratados desde una perspectiva zoogeográfica. Mollusca (611 especies, Polychaeta (403 y Crustacea (370 corresponden a los grupos mejor representados a lo largo de la costa chilena, determinantes en el patrón global de la biodiversidad. Este aumenta suavemente de norte a sur, interrumpido por máximos que sugieren esfuerzos diferenciales de estudio más que un comportamiento natural de la biodiversidad. El grado de agrupamiento entre las zonas muestra las tres unidades biogeográficas definidas recientemente por Lancellotti & Vásquez. Este arreglo, que representa lo exhibido por los grupos más diversos, se ve alterado en los grupos menos representados donde las diferencias obedecen al patrón de afinidades mostradas por las zonas comprendidas dentro de la Región Templada Transicional. El quiebre zoogeográfico alrededor de los 41º S, sugerido largamente en la literatura, sólo ocurre en Echinodermata y Demospongiae, evidenciando en los otros taxa la existencia de un área de transición entre los 35º y 48º S, caracterizada por un reemplazo gradual de especies. Dentro de las regiones la biodiversidad muestra homogeneidad, contrario al endemismo, el que alcanza un máximo de 52% en la Región Templada Fría y que parece ser consecuencia del alto número de especies con registros únicos (38,2% de especies citadas para una sóla zona. Esto sugiere un desconocimiento de los macroinvertebrados chilenos (distribución y diversidad, sobrestimando el endemismo regional y distorsionando los patrones locales de biodiversidadThe diversity of marine macroinvertebrates has received increasing

  19. Between-Habitat Variation of Benthic Cover, Reef Fish Assemblage and Feeding Pressure on the Benthos at the Only Atoll in South Atlantic: Rocas Atoll, NE Brazil

    OpenAIRE

    Longo, G. O.; Morais, R. A.; C D L Martins; Mendes, T. C.; Aued, A. W.; Cândido, D. V.; Oliveira, J. C.; L T Nunes; Fontoura, L.; M N Sissini; Teschima, M. M.; M. B. Silva; Ramlov, F.; Gouvea, L. P.; Ferreira, C. E. L.

    2015-01-01

    The Southwestern Atlantic harbors unique and relatively understudied reef systems, including the only atoll in South Atlantic: Rocas atoll. Located 230 km off the NE Brazilian coast, Rocas is formed by coralline red algae and vermetid mollusks, and is potentially one of the most "pristine" areas in Southwestern Atlantic. We provide the first comprehensive and integrative description of the fish and benthic communities inhabiting different shallow reef habitats of Rocas. We studied two contras...

  20. Cold seep and oxygen minimum zone associated sources of margin heterogeneity affect benthic assemblages, diversity and nutrition at the Cascadian margin (NE Pacific Ocean)

    OpenAIRE

    Guilini, K.; Levin, L. A.; Vanreusel, A.

    2012-01-01

    Hydrate Ridge (HR), located on the northeastern Pacific margin off Oregon, is characterized by the presence of outcropping hydrates and active methane seepage. Additionally, permanent low oxygen conditions overlay the benthic realm. This study evaluated the relative influence of both seepage and oxygen minima as sources of habitat heterogeneity and potential stress-inducing features on the bathyal metazoan benthos (primarily nematodes) at three different seep and non-seep HR locations, expose...

  1. Deforestation and benthic indicators: how much vegetation cover is needed to sustain healthy Andean streams?

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    Carlos Iñiguez-Armijos

    Full Text Available Deforestation in the tropical Andes is affecting ecological conditions of streams, and determination of how much forest should be retained is a pressing task for conservation, restoration and management strategies. We calculated and analyzed eight benthic metrics (structural, compositional and water quality indices and a physical-chemical composite index with gradients of vegetation cover to assess the effects of deforestation on macroinvertebrate communities and water quality of 23 streams in southern Ecuadorian Andes. Using a geographical information system (GIS, we quantified vegetation cover at three spatial scales: the entire catchment, the riparian buffer of 30 m width extending the entire stream length, and the local scale defined for a stream reach of 100 m in length and similar buffer width. Macroinvertebrate and water quality metrics had the strongest relationships with vegetation cover at catchment and riparian scales, while vegetation cover did not show any association with the macroinvertebrate metrics at local scale. At catchment scale, the water quality metrics indicate that ecological condition of Andean streams is good when vegetation cover is over 70%. Further, macroinvertebrate community assemblages were more diverse and related in catchments largely covered by native vegetation (>70%. Our results suggest that retaining an important quantity of native vegetation cover within the catchments and a linkage between headwater and riparian forests help to maintain and improve stream biodiversity and water quality in Andean streams affected by deforestation. This research proposes that a strong regulation focused to the management of riparian buffers can be successful when decision making is addressed to conservation/restoration of Andean catchments.

  2. The Relative Influence of Catchment and Site Variabbles on Fish and Macroinvertebrate Richness in Cerrado Biome Streams

    Science.gov (United States)

    Landscape and site-scale data aid the interpretation of biological data and management alternatives. We evaluated how three classes of environmental variables (natural landscape, anthropogenic pressures, and local physical habitat), influence fish and macroinvertebrate assemblage...

  3. The Effects of the Landguard™ A900 Enzyme on the Macroinvertebrate Community in the Salinas River, California, United States of America.

    Science.gov (United States)

    Phillips, Bryn M; Anderson, Brian S; Siegler, Katie; Voorhees, Jennifer P; Budd, Robert; Tjeerdema, Ron

    2016-02-01

    Agricultural use of organophosphate pesticides are responsible for surface water toxicity in California and has led to a number of impaired water body listings under section 303(d) of the Clean Water Act. Integrated passive-treatment systems can reduce pesticide loading in row crop runoff, but they are only partially effective for the more soluble organophosphates. The Landguard™ enzyme has been effectively proven as an on-farm management practice for the removal of chlorpyrifos and diazinon in furrow runoff, but it has not been used in larger-scale treatment because of concerns regarding the potential impact on in-stream macroinvertebrates after chronic use. A first-order agricultural creek was treated with the Landguard enzyme for 30 days approximately 450 m upstream of its intersection with the Salinas River. Toxicity and pesticide chemistry were measured in the creek during treatment as well as in the river both upstream and downstream of the creek input before and after treatment. Benthic macroinvertebrates were also surveyed in the river before and after enzyme treatment. Low concentrations of organophosphate pesticides were detected in the creek, but Landguard removed detected concentrations of chlorpyrifos. Toxicity detected in the creek was likely caused by pyrethroid pesticides, and no toxicity was detected in river samples. There were no differences in habitat or macroinvertebrate assemblages between upstream and downstream samples or between pre- and post-treatment samples. These results indicate that chronic treatment of the creek with Landguard enzyme had no impact on macroinvertebrate community structure in the river. PMID:26118992

  4. Benthic macrofaunal dynamics and environmental stress across a salt wedge Mediterranean estuary.

    Science.gov (United States)

    Nebra, Alfonso; Alcaraz, Carles; Caiola, Nuno; Muñoz-Camarillo, Gloria; Ibáñez, Carles

    2016-06-01

    The spatial distribution of benthic macroinvertebrate community in relation to environmental factors was studied along the Ebro Estuary (NE Iberian Peninsula), a salt wedge Mediterranean estuary. Both ordination methods and generalized additive models were performed to identify the different benthic assemblages and their relationship to abiotic factors. Our results showed a strong relationship between macrofaunal assemblages and the predominant environmental gradients (e.g. salinity); thus revealing spatial differences in their structure and composition. Two different stretches were identified, namely the upper (UE) and the lower Ebro Estuary (LE). UE showed riverine characteristics and hence was colonized by a freshwater community; whereas LE was influenced by marine intrusion and sustained a complex marine-origin community. However, within each stretch, water and sediment characteristics played an important role in explaining species composition differences among sampling stations. Moreover, outcomes suggested a total species replacement pattern, instead of the nestedness pattern usually associated with well-mixed temperate estuaries. The sharp species turnover together with the estuarine stratification point out that the Ebro Estuary is working, in terms of ecological boundaries, under an ecotone model. Finally, despite obvious differences with well mixed estuaries (i.e. lack of tidal influence, stratification and species turnover), the Ebro Estuary shares important ecological attributes with well-mixed temperate estuaries. PMID:27062106

  5. Categorização funcional trófica das comunidades de macroinvertebrados de dois reservatórios na região Centro-Oeste do Estado de São Paulo, Brasil - DOI: 10.4025/actascibiolsci.v31i1.331 Functional feeding groups of benthics macroinvertebrates communities of two lentic systems in the central west region of São Paulo State - DOI: 10.4025/actascibiolsci.v31i1.331

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    Jandira Liria Biscalquini Talamoni

    2009-04-01

    Full Text Available A utilização do conceito de guilda pode ser útil para a categorização funcional trófica de comunidades, pois não há obrigatoriedade da identificação dos organismos em nível de espécie, nem de tratar cada espécie como uma entidade separada. O objetivo deste estudo foi analisar os grupos funcionais tróficos (coletores-catadores, coletores-filtradores, fragmentadores, predadores e raspadores das comunidades de macroinvertebrados de dois reservatórios da região Centro-Oeste do Estado de São Paulo, Brasil. As amostragens foram realizadas nos períodos chuvoso (março/abril - 2001 e de seca (julho/agosto - 2001 e os dados obtidos indicam que os coletores-catadores foram a guilda mais frequente. Este fato sugere grande importância da matéria orgânica como recurso alimentar na dieta dos macroinvertebrados analisados.The aim of this study was analyze the functional feeding groups (collectors, shredders, predators and grazer-scrapers of benthic macroinvertebrates communities in two lentic systems in the central west region of São Paulo State. The samples were realized in rainy (March/April - 2001 and dry (July/August - 2001 seasons. The results obtained contribute for the best knowledgement of benthic macroinvertebrate community on those two systems.

  6. DISTRIBUTION AND OCCURRENCE OF BENTHIC MACROINVERTEBRATES IN RIVERS WITH RICE CULTURE AREA IN ITAJAÍ VALLEY - SC = DISTRIBUIÇÃO E OCORRÊNCIA DE MACROINVERTEBRADOS BENTÔNICOS EM RIOS NAS ÁREAS COM CULTURA ORIZÍCOLA NO VALE DO ITAJAÍ-SC

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    Joseline Molozzi

    2009-01-01

    Full Text Available Rice is one of the main cereals grown in Brazil. The handling of the rice culture may impact in the river downstream of the farming. The main goal of this research was to evaluate the distribution and occurrence of benthic macroinvertebrates in rivers with rice plantations. This research was developed in the cities of Gaspar and Agrolândia, in Itajaí River Basin, Santa Catarina, Brazil. In Gaspar City, macroinvertebrate data and environmental information were collected quarterly, in August/04, November/04 and February/05. In Agrolândia City, they were also collected quarterly in October/04, January/05 and April/05. Benthic macroinvertebrates samples were collected using Surber sampler. The macroinvertebrates were identified at family level. Diversity was estimated using Shannon, Margalef and Evenness Indices. To compare the diversity among these sites, T Student Test was used. Richness and Dominance were also determinated. 21.831 organisms were collected at the six sites. 73% were Diptera with predominance of Chironomidae family with 14.956 individuals. Site 4 had the lowest diversity and the highest dominance. In rivers under influence of the rice culture it is observed predominance of taxons resistant to pollution. Taxons more sensitive to pollution were hardly found at the six sites, demonstrating the inappropriate conditions for their development. = O arroz é um dos principais cereais cultivados no Brasil. No manejo desta cultura é possível que ocorra um impacto no corpo hídrico à jusante das lavouras. Este trabalho teve por objetivo estudar a distribuição e ocorrência de macroinvertebrados bentônicos em rios nas áreas com cultura orizícola. O estudo foi desenvolvido nos municípios de Gaspar e Agrolândia, localizados na bacia do Itajaí, SC. As coletas foram realizadas trimestralmente, em agosto e novembro de 2004 e fevereiro de 2005 em Gaspar, outubro de 2004, janeiro e abril de 2005 em Agrolândia. As amostras de

  7. Sampling strategies for biotope definition: minimal sampling area for selected groups of macroinvertebrates in the rocky subtidal of São Miguel, Azores.

    OpenAIRE

    Martins, Gustavo M.; Wallenstein, Francisco; Álvaro, Nuno V.; Neto, Ana I.; Costa, Ana C.

    2005-01-01

    Azorean rocky shores are mainly characterized by patchy algae-based communities with variable associated macrofauna. Characterization studies should therefore include quantitative information for both algae and macroinvertebrates. Unlike for the algae, minimal sampling areas are undefined for macroinvertebrates in the Azores. The present study defines the minimal area to be used for the assessment of the abundance of conspicuous benthic macroinvertebrate abundance. This study proposes methodo...

  8. Prey distribution, physical habitat features, and guild traits interact to produce contrasting shorebird assemblages among foraging patches.

    Directory of Open Access Journals (Sweden)

    Beth M VanDusen

    Full Text Available Worldwide declines in shorebird populations, driven largely by habitat loss and degradation, motivate environmental managers to preserve and restore the critical coastal habitats on which these birds depend. Effective habitat management requires an understanding of the factors that determine habitat use and value to shorebirds, extending from individuals to the entire community. While investigating the factors that influenced shorebird foraging distributions among neighboring intertidal sand flats, we built upon species-level understandings of individual-based, small-scale foraging decisions to develop more comprehensive guild- and community-level insights. We found that densities and community composition of foraging shorebirds varied substantially among elevations within some tidal flats and among five flats despite their proximity (all located within a 400-m stretch of natural, unmodified inlet shoreline. Non-dimensional multivariate analyses revealed that the changing composition of the shorebird community among flats and tidal elevations correlated significantly (ρ(s = 0.56 with the spatial structure of the benthic invertebrate prey community. Sediment grain-sizes affected shorebird community spatial patterns indirectly by influencing benthic macroinvertebrate community compositions. Furthermore, combining sediment and macroinvertebrate information produced a 27% increase in correlation (ρ(s = 0.71 with shorebird assemblage patterns over the correlation of the bird community with the macroinvertebrate community alone. Beyond its indirect effects acting through prey distributions, granulometry of the flats influenced shorebird foraging directly by modifying prey availability. Our study highlights the importance of habitat heterogeneity, showing that no single patch type was ideal for the entire shorebird community. Generally, shorebird density and diversity were greatest at lower elevations on flats when they became exposed; these

  9. Comparison of live and dead molluscan assemblages suggests recent human-driven decline in benthic diversity in Phetchaburi (NW Gulf of Thailand)

    Science.gov (United States)

    Negri, Mauro Pietro; Sanfilippo, Rossana; Basso, Daniela; Rosso, Antonietta

    2015-12-01

    Dead and live molluscan assemblages from the coastal area of Phetchaburi (NW Gulf of Thailand) were compared by means of multivariate analysis. Seven thanatofacies were recognized, thriving in the area after the 1960s. Five of them, scattered along the tidal flat, represent oligotypic intertidal biotopes linked to a variety of environmental factors; the remaining two mirror high-diversity infralittoral associations. Conversely, only two poor, ill-defined biofacies thrive at present between the intertidal and the shallow infralittoral zones, somewhat resembling two of the thanatofacies. Diversity indexes reveal a dramatic biodiversity decline occurred from the 1960s onwards, far beyond the effects of time-averaging and accumulation. The responsibility for this reduction is largely attributable to the high impact of human activities, such as the intensive sea bottom trawling, the wastewaters from aquaculture (shrimp and fish ponds) and dense coastal villages, and, at a minor extent, the digging of edible molluscs from the tidal flat.

  10. Benthic Assemblages of the Anton Dohrn Seamount (NE Atlantic: Defining Deep-Sea Biotopes to Support Habitat Mapping and Management Efforts with a Focus on Vulnerable Marine Ecosystems.

    Directory of Open Access Journals (Sweden)

    Jaime S Davies

    Full Text Available In 2009 the NW and SE flanks of Anton Dohrn Seamount were surveyed using multibeam echosounder and video ground-truthing to characterise megabenthic biological assemblages (biotopes and assess those which clearly adhere to the definition of Vulnerable Marine Ecosystems, for use in habitat mapping. A combination of multivariate analysis of still imagery and video ground-truthing defined 13 comprehensive descriptions of biotopes that function as mapping units in an applied context. The data reveals that the NW and SE sides of Anton Dohrn Seamount (ADS are topographically complex and harbour diverse biological assemblages, some of which agree with current definitions of 'listed' habitats of conservation concern. Ten of these biotopes could easily be considered Vulnerable Marine Ecosystems; three coral gardens, four cold-water coral reefs, two xenophyophore communities and one sponge dominated community, with remaining biotopes requiring more detailed assessment. Coral gardens were only found on positive geomorphic features, namely parasitic cones and radial ridges, found both sides of the seamount over a depth of 1311-1740 m. Two cold-water coral reefs (equivalent to summit reef were mapped on the NW side of the seamount; Lophelia pertusa reef associated with the cliff top mounds at a depth of 747-791 m and Solenosmilia variabilis reef on a radial ridge at a depth of 1318-1351 m. Xenophyophore communities were mapped from both sides of the seamount at a depth of 1099-1770 m and were either associated with geomorphic features or were in close proximity (< 100 m to them. The sponge dominated community was found on the steep escarpment either side of the seamount over at a depth of 854-1345 m. Multivariate diversity revealed the xenophyophore biotopes to be the least diverse, and a hard substratum biotope characterised by serpulids and the sessile holothurian, Psolus squamatus, as the most diverse.

  11. Spatial and seasonal distribution of macroinvertebrates in high altitude reservoir (Beyler Reservoir, Turkey)

    Science.gov (United States)

    Findik, Özlem

    2013-09-01

    A highland reservoir in the West Black Sea region of Turkey which belongs to the Mediterranean climatic zone was examined. Both littoral and profundal zones were sampled from October 2009 to September 2010, to determine taxonomic composition, biodiversity and abundance of benthic invertebrates as well as the seasonal variation of these measures. A total of 35 taxa were identified, of which 12 belong to Chironomidae and 10 to Oligochaeta groups. The highest diversity and abundance of benthic macroinvertebrates were found at the littoral stations. Macroinvertebrates showed significant positive correlations with water temperature and NO2 and NO3 concentrations, and negative correlation with dissolved oxygen.

  12. Effect of Ocean Acidification and pH Fluctuations on the Growth and Development of Coralline Algal Recruits, and an Associated Benthic Algal Assemblage.

    Directory of Open Access Journals (Sweden)

    Michael Y Roleda

    Full Text Available Coralline algae are susceptible to the changes in the seawater carbonate system associated with ocean acidification (OA. However, the coastal environments in which corallines grow are subject to large daily pH fluctuations which may affect their responses to OA. Here, we followed the growth and development of the juvenile coralline alga Arthrocardia corymbosa, which had recruited into experimental conditions during a prior experiment, using a novel OA laboratory culture system to simulate the pH fluctuations observed within a kelp forest. Microscopic life history stages are considered more susceptible to environmental stress than adult stages; we compared the responses of newly recruited A. corymbosa to static and fluctuating seawater pH with those of their field-collected parents. Recruits were cultivated for 16 weeks under static pH 8.05 and 7.65, representing ambient and 4× preindustrial pCO2 concentrations, respectively, and two fluctuating pH treatments of daily [Formula: see text] (daytime pH = 8.45, night-time pH = 7.65 and daily [Formula: see text] (daytime pH = 8.05, night-time pH = 7.25. Positive growth rates of new recruits were recorded in all treatments, and were highest under static pH 8.05 and lowest under fluctuating pH 7.65. This pattern was similar to the adults' response, except that adults had zero growth under fluctuating pH 7.65. The % dry weight of MgCO3 in calcite of the juveniles was reduced from 10% at pH 8.05 to 8% at pH 7.65, but there was no effect of pH fluctuation. A wide range of fleshy macroalgae and at least 6 species of benthic diatoms recruited across all experimental treatments, from cryptic spores associated with the adult A. corymbosa. There was no effect of experimental treatment on the growth of the benthic diatoms. On the community level, pH-sensitive species may survive lower pH in the presence of diatoms and fleshy macroalgae, whose high metabolic activity may raise the pH of the local microhabitat.

  13. Macroinvertebrates of the Iranian running waters: a review

    OpenAIRE

    Moslem Sharifinia

    2015-01-01

    Abstract A comprehensive review of macroinvertebrate studies conducted along the Iranian running waters over the last 15 years has been made by providing the most updated checklist of the Iranian running waters benthic invertebrates. Running waters ecosystems are complex environments known for their importance in terms of biodiversity. As part of the analysis, we endeavored to provide the critical re-identification of the reported species by through comparisons with the database of the Animal...

  14. Evaluating the response of biological assemblages as potential indicators for restoration measures in an intermittent Mediterranean river.

    Science.gov (United States)

    Hughes, Samantha Jane; Santos, Jose; Ferreira, Teresa; Mendes, Ana

    2010-08-01

    Bioindicators are essential for detecting environmental degradation and for assessing the success of river restoration initiatives. River restoration projects require the identification of environmental and pressure gradients that affect the river system under study and the selection of suitable indicators to assess habitat quality before, during and after restoration. We assessed the response of benthic macroinvertebrates, fish, bird and macrophyte assemblages to environmental and pressure gradients from sites situated upstream and downstream of a cofferdam on the River Odelouca, an intermittent Mediterranean river in southwest Portugal. The Odelouca will be permanently dammed in 2010. Principal Component Analyses (PCA) of environmental and pressure variables revealed that most variance was explained by environmental factors that clearly separated sites upstream and downstream of the partially built cofferdam. The pressure gradient describing physical impacts to the banks and channel as a result of land use change was less distinct. Redundancy Analysis revealed significant levels of explained variance to species distribution patterns in relation to environmental and pressure variables for all 4 biological assemblages. Partial Redundancy analyses revealed high levels of redundancy for pH between groups and that the avifauna was best associated with pressures acting upon the system. Patterns in invertebrates and fish were associated with descriptors of habitat quality, although fish distribution patterns were affected by reduced connectivity. Procrustean and RELATE (Mantel test) analyses gave broadly similar results and supported these findings. We give suggestions on the suitability of key indicator groups such as benthic macroinvertebrates and endemic fish species to assess in stream habitat quality and appropriate restoration measures, such as the release of peak flow patterns that mimic intermittent Mediterranean systems to combat habitat fragmentation and

  15. Evaluating the Response of Biological Assemblages as Potential Indicators for Restoration Measures in an Intermittent Mediterranean River

    Science.gov (United States)

    Hughes, Samantha Jane; Santos, Jose; Ferreira, Teresa; Mendes, Ana

    2010-08-01

    Bioindicators are essential for detecting environmental degradation and for assessing the success of river restoration initiatives. River restoration projects require the identification of environmental and pressure gradients that affect the river system under study and the selection of suitable indicators to assess habitat quality before, during and after restoration. We assessed the response of benthic macroinvertebrates, fish, bird and macrophyte assemblages to environmental and pressure gradients from sites situated upstream and downstream of a cofferdam on the River Odelouca, an intermittent Mediterranean river in southwest Portugal. The Odelouca will be permanently dammed in 2010. Principal Component Analyses (PCA) of environmental and pressure variables revealed that most variance was explained by environmental factors that clearly separated sites upstream and downstream of the partially built cofferdam. The pressure gradient describing physical impacts to the banks and channel as a result of land use change was less distinct. Redundancy Analysis revealed significant levels of explained variance to species distribution patterns in relation to environmental and pressure variables for all 4 biological assemblages. Partial Redundancy analyses revealed high levels of redundancy for pH between groups and that the avifauna was best associated with pressures acting upon the system. Patterns in invertebrates and fish were associated with descriptors of habitat quality, although fish distribution patterns were affected by reduced connectivity. Procrustean and RELATE (Mantel test) analyses gave broadly similar results and supported these findings. We give suggestions on the suitability of key indicator groups such as benthic macroinvertebrates and endemic fish species to assess in stream habitat quality and appropriate restoration measures, such as the release of peak flow patterns that mimic intermittent Mediterranean systems to combat habitat fragmentation and

  16. Are macroinvertebrates in high altitude streams affected by oxygen deficiency?

    DEFF Research Database (Denmark)

    Jacobsen, Dean; Rostgaard, S.; Vásconez, J. J.

    2003-01-01

    1. The solubility of oxygen in water increases with decreasing temperature. This has led to a general perception of cold, high mountain streams as more oxygen rich than warmer lowland streams, and that macroinvertebrates inhabiting high altitude streams have had no need to adapt to critical oxygen...... conditions. However, this fails to take into account that oxygen solubility declines with decreasing atmospheric pressure, which may be of importance at high altitudes. 2. Based on samples of macroinvertebrate benthos and in situ measurements of respiratory oxygen demand of macroinvertebrates in small...... include relatively few groups normally regarded as oxygen-sensitive. Nevertheless, high altitude assemblages react more strongly to lowering of oxygen saturation, and are thus more sensitive to organic pollution. 5. Oxygen deficiency has been overlooked completely in studies of the altitudinal...

  17. Benthic diatoms in lakes

    OpenAIRE

    Gottschalk, Steffi

    2014-01-01

    In order to protect or improve surface waters ecosystem response to pressures needs to be quantified. Diatoms are frequently used for assessing ecological status in streams and for reconstructing water quality of lakes. However, ecological status assessment of European lakes based on extant diatom assemblages is rare. The overall aim of this thesis is to facilitate the application of benthic diatoms in water quality assessment of boreal lakes, using methods developed for stream assessmen...

  18. [Distribution and species composition of hyporheic macroinvertebrates in a mountain stream].

    Science.gov (United States)

    Zhang, Yue-wei; Yuan, Xing-zhong; Liu, Hong; Ren, Hai-qing; Deng, Wei; Wang, Xiao-feng

    2015-09-01

    Hyporheic macroinvertebrates are an important component of stream ecosystem. The composition and distribution of the hyporheic macroinvertebrates were investigated using artificial substrates in the upper reaches of Heishuitan River in August, December 2013 and April 2014. The results indicated that a total of 27 microinvertbrate species were identified in all three seasons. In summer, 22 species were identified, accounting for 81.8% of aquatic insects. 16 species were identified both in winter and spring, accounting for 75.0% and 62.5% of aquatic insects, respectively. The density of macroinvertebrate assemblage was significantly lower in summer than in winter and spring, and was the highest in spring. The biomass of macroinvertebrate assemblage was significantly higher in winter than in summer and spring, and was the lowest in summer. Species richness, Shannon index and Pielou index all had no significant difference among the three seasons. The density and richness of macroinvertebrates decreased with bed depth, and the maximum invertebrate density was found within the top 20 cm of the stream bed. Collector-filterer and collector-gatherer were the dominant functional feeding group in all three seasons. The community structure and temporal-spatial distribution of macroinvertebrates were determined by interactions and life history strategy of macroinvertebrates, and physical-chemical factors of hyporheic zone. PMID:26785569

  19. Dispersal mechanisms of macroinvertebrates colonizing salmon flesh in a developing Alaskan stream

    Science.gov (United States)

    Monaghan, Kieran A.; Milner, Alexander M.

    2008-07-01

    Patterns of carcass colonization by macroinvertebrates suggest deterministic resource tracking. As salmon carcasses decay in riverine ecosystems, exudates and abraded particles enter the water column accompanied by qualitative changes in benthic biofilms. We used a combination of implanted substrates, controlled exposure experiments and descriptive surveys to examine dispersal and colonization behaviour of macroinvertebrates in a developing stream in the presence/absence of decaying salmon flesh. Macroinvertebrate colonization of implanted trays containing salmon flesh showed no relationship with their sequential downstream position and (potential) increasing gradient of decay products. Dispersal to trays was principally due to drift with colonization patterns indicative of resource evaluation by direct contact, as opposed to remote detection. Macroinvertebrates in enclosed exposure chambers switched between artificial channels with and without salmon flesh demonstrated no significant difference related to exposure history; chamber opening was followed by a net migration from both treatment and controls. In a companion experiment, macroinvertebrates freely colonizing rock baskets switched between channel treatments, demonstrated no significant difference related to exposure history. Although the distribution of macroinvertebrates in the stream corresponded to habitats where carcasses accumulated, macroinvertebrate density in respective habitats was unrelated to carcass densities. The absence of a behavioural dispersal response to the presence of decaying salmon flesh in this study might be explained by the spatio-temporal design of the experiments, the use of previously frozen flesh as opposed to fresh carcasses, and the relatively early developmental stage of this stream and its associated macroinvertebrate community.

  20. Contrasting responses of coral reef fauna and foraminiferal assemblages to human influence in La Parguera, Puerto Rico

    Science.gov (United States)

    Coral reef biota including stony corals, sponges, gorgonians, fish, benthic macroinvertebrates and foraminifera were surveyed in coastal waters near La Parguera, in southwestern Puerto Rico. The goal was to evaluate sensitivity of coral reef biological indicators to human distur...

  1. The effects of tricyclazole treatment on aquatic macroinvertebrates in the field and in laboratory

    OpenAIRE

    B. Rossaro; Cortesi, P

    2013-01-01

    The effects of tricyclazole treatments on benthic macroinvertebrates in the field and in laboratory were studied. In field conditions, low density of benthic populations was observed, both in treated and untreated plots, which was attributed to the short period of submersion of the rice field and high water temperature, fungicide treatments had no significant effect. Both laboratory acute toxicity test and a test using a mesocosm suggested a low toxicity of tricyclazole on invertebrates. A re...

  2. Macroinvertebrate diets reflect tributary inputs and turbidity-driven changes in food availability in the Colorado River downstream of Glen Canyon Dam

    Science.gov (United States)

    Wellard Kelly, Holly A.; Rosi-Marshall, Emma J.; Kennedy, Theodore A.; Hall, Robert O., Jr.; Cross, Wyatt F.; Baxter, Colden V.

    2013-01-01

    Physical changes to rivers associated with large dams (e.g., water temperature) directly alter macroinvertebrate assemblages. Large dams also may indirectly alter these assemblages by changing the food resources available to support macroinvertebrate production. We examined the diets of the 4 most common macroinvertebrate taxa in the Colorado River through Glen and Grand Canyons, seasonally, at 6 sites for 2.5 y. We compared macroinvertebrate diet composition to the composition of epilithon (rock and cliff faces) communities and suspended organic seston to evaluate the degree to which macroinvertebrate diets tracked downstream changes in resource availability. Diets contained greater proportions of algal resources in the tailwater of Glen Canyon Dam and more terrestrial-based resources at sites downstream of the 1st major tributary. As predicted, macroinvertebrate diets tracked turbidity-driven changes in resource availability, and river turbidity partially explained variability in macroinvertebrate diets. The relative proportions of resources assimilated by macroinvertebrates ranged from dominance by algae to terrestrial-based resources, despite greater assimilation efficiencies for algal than terrestrial C. Terrestrial resources were most important during high turbidity conditions, which occurred during the late-summer monsoon season (July–October) when tributaries contributed large amounts of organic matter to the mainstem and suspended sediments reduced algal production. Macroinvertebrate diets were influenced by seasonal changes in tributary inputs and turbidity, a result suggesting macroinvertebrate diets in regulated rivers may be temporally dynamic and driven by tributary inputs.

  3. Weak Concordance between Fish and Macroinvertebrates in Mediterranean Streams

    OpenAIRE

    Stefano Larsen; Laura Mancini; Giorgio Pace; Massimiliano Scalici; Lorenzo Tancioni

    2012-01-01

    Although anthropogenic degradation of riverine systems stimulated a multi-taxon bioassessment of their ecological integrity in EU countries, specific responses of different taxonomic groups to human pressure are poorly investigated in Mediterranean rivers. Here, we assess if richness and composition of macroinvertebrate and fish assemblages show concordant variation along a gradient of anthropogenic pressure in 31 reaches across 13 wadeable streams in central Italy. Fish and invertebrate taxo...

  4. The fauna structure of benthic macro-invertebrates for environmental restoration in a eutrophic lake using water hyacinths.%水葫芦修复富营养化湖泊水体区域内外底栖动物群落特征

    Institute of Scientific and Technical Information of China (English)

    王智; 张志勇; 张君倩; 张迎颖; 严少华

    2012-01-01

    From August to October in 2010, approximately 70 hectares of water hyacinth were planted at the Baishan Bay in Lake Dianchi and benthic macro-invertebrates were sampled. The densities of benthic macro-invertebrates in water hyacinth area (WHA), near water hyacinth area (NWHA) and far water hyacinth area (FWHA) were 294.5,159 and 261 ind/m2, respectively. Amongst of all present species, oligochaete Limnodrilus hoffmeisteri was the dominant species, representing 68.3% (WHA), 59.6% (NWHA) and 86.0% (FWHA). Stepwise regression analysis showed a significantly positive relationship (P < 0.01) between the densities of Limnodrilus hoffineisteri to the total phosphorus (TP) in the water and Labile-P in the sediment. Limnodrilus hoffineisteri was a good indicator of eutrophication. The richness and biodiversity in WHA were higher (P < 0.05) than that in the NWHA and FWHA. The richness of benthic macro-invertebrates was 14 in WHA, 10 in NWHA and 6 in FWHA, respectively. Shannon-Wiener diversity indexes in WHA, NWHA and FWHA were 1.10, 0.57 and 0.54, respectively. After planting water hyacinth in the lake, in WHA and NWHA, the Margalef index, Shannon-Wiener index, Simpson index and Peilou index in October 2010 were significantly increased comparing to August and September 2010 (P< 0.05). However, these indexes were not significantly different at FWHA during the research intervals. A controlled presence of water hyacinth is not harmful to benthic invertebrates in a eutrophic lake.%于2010年8~10月对滇池白山湾人工控制性种养的约70hm2的水葫芦区、近水葫芦区和远水葫芦区采样分析,探讨了水葫芦种养工程区域内外底栖动物群落结构特征.结果表明,在水葫芦区、近水葫芦区及远水葫芦区,底栖动物总密度分别为294.5,159,261ind/m2,其中寡毛类的霍甫水丝蚓(Limnodrilus hoffmeisteri)为绝对优势种,分别占各自区域总密度的68.3%,59.6%和86.0%.逐步回归分析显示,水体总磷(TP)和底

  5. Influence of environmental factors on benthic macroinvertebrate communities of urban streams in Vereda habitats, Central Brazil Influência de variáveis ambientais na comunidade de macroinvertebrados bentônicos de córregos urbanos de Veredas, Brasil Central

    Directory of Open Access Journals (Sweden)

    Renata de Moura Guimaraes Souto

    2011-09-01

    Full Text Available AIM: Veredas and the aquatic and semi-aquatic communities play a key role in watershed protection in the Cerrado Biome. Information about the effects of physical and chemical variables and habitat integrity on benthic communities has been increased in recent years; however, there is no study evaluating the influence of urbanization on macroinvertebrates of Vereda streams. Thus, improving the knowledge of the relationship between abiotic properties and benthic fauna is very important for understanding the functioning of ecological processes and health of aquatic ecosystems. This study investigated the influence of physical and chemical variables on benthic macroinvertebrate communities along a gradient of anthropogenic disturbance in four Vereda streams in Uberlândia (MG, one in a preserved area and three in the urban area; METHODS: samplings were collected during the dry and rainy seasons; RESULTS: principal component analysis separated the stream in the preserved area from those in the urban area by having lower values of BOD, COD, sediment size, conductivity, detergents, pH, deposited solids and total dissolved solids. Pollution sensitive groups (e.g., Ephemeroptera and Trichoptera were associated to the stream in the preserved area, and more tolerant groups (e.g., Chironomidae and Oligochaeta had greater abundance in the streams of the urban area. Canonical Correspondence Analysis indicated that dissolved oxygen, conductivity, BOD, oil and grease, and turbidity explained 56% of the variance in the distribution and abundance of macroinvertebrates; CONCLUSIONS: Benthic communities of Vereda streams in urban areas in the Cerrado Biome seem to be highly affected by human activities that increase water organic pollution and sedimentation.OBJETIVO: Veredas e comunidades aquáticas e semi-aquáticas desempenham importante papel na proteção das bacias hidrográficas no Bioma Cerrado. Informações sobre efeitos de variáveis físico-químicas e da

  6. Steel creek macroinvertebrates: L Lake/steel creek biological monitoring program January 1986--December 1987

    Energy Technology Data Exchange (ETDEWEB)

    O' Hop, J.R.; Lauritsen, D.; Magoulik, D.

    1988-04-01

    The macroinvertebrate community in Steel Creek was monitored at 13 sampling stations from January 1986 to December 1987 to assess the effects of L-Lake impoundment on the biological community downstream from the dam. The benthic macroinvertebrate communities were sampled monthly at 13 stations in Steel Creek using artificial substrates. Macroinvertebrates suspended in the water column were collected monthly at seven stations using drift nets. Emerging aquatic insects were sampled monthly at seven stations with floating emergence traps. Invertebrates on natural substrates (bottom sediments, snags, and macrophytes) were collected at seven stations in May and September in both 1986 and 1987. Macroinvertebrates were collected in February and August of 1986 and 1987 at 13 stations in Steel Creek using dip nets. 61 refs., 79 figs., 18 tabs.

  7. Choosing the best non-parametric richness estimator for benthic macroinvertebrates databases Eligiendo el mejor estimador no paramétrico para calcular riqueza en bases de datos de macroinvertebrados bentónicos

    Directory of Open Access Journals (Sweden)

    Carola V. Basualdo

    2011-06-01

    Full Text Available Non-parametric estimators allow to compare the estimates of richness among data sets from heterogeneous sources. However, since the estimator performance depends on the species-abundance distribution of the sample, preference for one or another is a difficult issue. The present study recovers and revalues some criteria already present in the literature in order to choose the most suitable estimator for streams macroinvertebrates, and provides some tools to apply them. Two abundance and four incidence estimators were applied to a regional database at family and genus level. They were evaluated under four criteria: sub-sample size required to estimate the observed richness; constancy of the sub-sample size; lack of erratic behavior and similarity in curve shape through different data sets. Among incidence estimators, Jack1 had the best performance. Between abundance estimators, ACE was the best when the observed richness was small and Chao1 when the observed richness was high. The uniformity of curves shapes allowed to describe the general sequences of curves behavior that could act as references to compare estimations of small databases and to infer the possible behavior of the curve (i.e the expected richness if the sample were larger. These results can be very useful for environmental management, and update the state of knowledge of regional macroinvertebrates.Los estimadores no paramétricos permiten comparar la riqueza estimada de conjuntos de datos de origen diverso. Empero, como su comportamiento depende de la distribución de abundancia del conjunto de datos, la preferencia por alguno representa una decisión difícil. Este trabajo rescata algunos criterios presentes en la literatura para elegir el estimador más adecuado para macroinvertebrados bentónicos de ríos y ofrece algunas herramientas para su aplicación. Cuatro estimadores de incidencia y dos de abundancia se aplicaron a un inventario regional a nivel de familia y género. Para

  8. Controlling factors of benthic macroinvertebrates distribution in a small tropical pond, lateral to the Paranapanema River (São Paulo, Brazil Macroinvertebrados bentônicos e fatores controladores de sua distribuição em uma pequena lagoa tropical adjacente ao rio Paranapanema (São Paulo, Brasil

    Directory of Open Access Journals (Sweden)

    Erika Mayumi Shimabukuro

    2011-06-01

    Full Text Available AIM: The aim of the present study was to examine the benthic fauna in a marginal pond lateral to the Paranapanema River and to identify the main controlling factors of its distribution. Considering the small size of the lacustrine ecosystem, we expected that seasonal variations of the benthic community attributes are more important than spatial variations; METHODS: Two samplings, one in March and another in August, were carried out at nine sites in the pond. Sediment samples were obtained through a Van Veen grab for invertebrate sorting, granulometric analysis, and for quantification of organic matter in sediment. Other abiotic factors were measured, such as water transparency, dissolved oxygen, pH, electric conductivity, temperature, and depth of sediment sampling sites. Regarding the comparative analysis at spatial scale, no significant variations in density of the benthic invertebrate community were found. RESULTS: In relation to the studied abiotic factors, only depth presented significant differences among sampling sites; All the measured environmental parameters presented significant differences among sampling months, except depth and the physical and chemical characteristics of the sediment. The abundance of Chaoboridae and Chironomidae was the unique attribute with a significant difference in comparing the two months. A higher abundance of taxa occurred in August, especially for Oligochaeta, Nematoda, Chaoboridae, and Chironomidae; CONCLUSIONS: Because of the low structural complexity of the studied pond, we concluded that the changes in benthic macroinvertebrate community attributes were mainly due to seasonal effects.OBJETIVO: O presente estudo tem por objetivo examinar a fauna bentônica em lagoa marginal ao rio Paranapanema e os principais fatores reguladores da sua distribuição. Devido ao pequeno tamanho do ambiente lacustre, procurou-se mostrar que as variações sazonais dos atributos da comunidade bentônica são mais

  9. Constitution of fish assemblages in three nearshore habitats and the effect of benthic macroalgae on fish assemblages in Gouqi Island%拘杞岛近岸3种生境鱼类群落组成及岩礁区底栖海藻对鱼类群落结构的影响

    Institute of Scientific and Technical Information of China (English)

    王蕾; 章守宇; 汪振华; 王凯; 林军

    2011-01-01

    Macroalgae covering on the rocky reef around coast of Gouqi Island were surveyed and sampled through diving during 2005 to 2006 and May to June 2010, in order to find out the distribution, constitution and life history of macroalgae. Two composing patterns of macroalgae were shown in the subtidal zone of rocky reef; one was dominated by standing macroalgae Sargassum horneri; another was dominated by smaller macroalgaes, such as Ulva pertusa, which is widely distributed both in intertidal and subtidal zone. The life history of S. Horneri showed the four stages of the larger kelp bed: young seedling development period (August to September) ,slow growth period of seeding (October to February in next year) ,fast growth and reproduction period (March to May) .decomposing and declining period (June to July). The smaller kelp bed exists the whole year, without much difference to outside of the kelp bed. To estimate the composition of fish assemblages in three habitats around Gouqi Island nearshore, I. E. Rocky reef, sandy beach and mussel cultivation rafts,we sampled the fish assemblages in three habitats by combined gill nets every month from February 2009 to January 2010. The indexes of Jaccard similarity, Margalef richness and Shannon-wiener diversity were used to compare the variety of fish community structures among habitats, combined with statistical analysis of variance, UPGMA and nMDS. It showed that the differences of fish community structures among above three habitats were significant. The dominant fish species in rocky reef habitat were Sebastiscus marmoratus, Agrammus agrammus and N. Albiflora. Fish community was mainly based on the demersal omnivorous rocky fishes, which prey mainly on benthic invertebrates living on macroalgaes. The dominant fish species in sandy beach habitat were Paraplagusia japonica and Nibea albiflora. Fish community was mainly based on the mid-lower migration fishes. For fish assemblages in mussel cultivation raft habitat, which were

  10. Constitution of fish assemblages in three nearshore habitats and the effect of benthic macroalgae on fish assemblages in Gouqi Island%拘杞岛近岸3种生境鱼类群落组成及岩礁区底栖海藻对鱼类群落结构的影响

    Institute of Scientific and Technical Information of China (English)

    王蕾; 章守宇; 汪振华; 王凯; 林军

    2011-01-01

    Macroalgae covering on the rocky reef around coast of Gouqi Island were surveyed and sampled through diving during 2005 to 2006 and May to June 2010, in order to find out the distribution, constitution and life history of macroalgae. Two composing patterns of macroalgae were shown in the subtidal zone of rocky reef; one was dominated by standing macroalgae Sargassum horneri; another was dominated by smaller macroalgaes, such as Ulva pertusa, which is widely distributed both in intertidal and subtidal zone. The life history of S. Horneri showed the four stages of the larger kelp bed: young seedling development period (August to September) ,slow growth period of seeding (October to February in next year) ,fast growth and reproduction period (March to May) .decomposing and declining period (June to July). The smaller kelp bed exists the whole year, without much difference to outside of the kelp bed. To estimate the composition of fish assemblages in three habitats around Gouqi Island nearshore, I. E. Rocky reef, sandy beach and mussel cultivation rafts,we sampled the fish assemblages in three habitats by combined gill nets every month from February 2009 to January 2010. The indexes of Jaccard similarity, Margalef richness and Shannon-wiener diversity were used to compare the variety of fish community structures among habitats, combined with statistical analysis of variance, UPGMA and nMDS. It showed that the differences of fish community structures among above three habitats were significant. The dominant fish species in rocky reef habitat were Sebastiscus marmoratus, Agrammus agrammus and N. Albiflora. Fish community was mainly based on the demersal omnivorous rocky fishes, which prey mainly on benthic invertebrates living on macroalgaes. The dominant fish species in sandy beach habitat were Paraplagusia japonica and Nibea albiflora. Fish community was mainly based on the mid-lower migration fishes. For fish assemblages in mussel cultivation raft habitat, which were

  11. Tools for the development of a benthic quality index for Italian lakes

    Directory of Open Access Journals (Sweden)

    Angelo SOLIMINI

    2006-02-01

    Full Text Available In this paper, we propose a methodology to develop a benthic quality index useful for Italian lakes. The existing data about benthic macroinvertebrates of the Italian lakes were collected over a period of 50 years, but only a few lakes such as the Maggiore and the Mergozzo have been intensely studied. Some large lakes such as Lake Como are still almost uninvestigated. In total, 570 benthic macroinvertebrate taxa were identified; of which 373 belong to Chironomidae and 85 to Oligochaeta. With the aim of relating environmental variables with macrobenthos assemblages, we carried out a canonical correlation analysis (CANON using a database that included 1060 sampling points. Both environmental (13 variables describing morphometry and hydrochemistry and biological data (57 taxa were available, but only taxa present in at least 10 samples were selected for data analysis. Three canonical variates were ecologically significant. The first one was correlated with conductivity, pH and alkalinity and accounted for 20% of the total variation. The second one was positively correlated with total phosphorus and N-NH4, and inversely with dissolved oxygen, and accounted for 18% of the total variation. The third one showed a direct correlation with maximum lake depth and volume and an inverse correlation with water temperature, and accounted for 17% of the total variation. A Trophic Status Index (TSI, based on the table 11 of the Italian Law 152/99 (without including chlorophyll, was calculated by ranking percent oxygen saturation, transparency and total phosphorus. TSI was used to test a Benthic Quality Index for Italian Lakes (BQIL which is proposed in the present paper. The algorithm considered three steps. First, the means of three variables were calculated: percent oxygen saturation, transparency and total phosphorus weighted by the taxa abundances. These values are interpreted as optimum for each taxon and used to assign an indicator weight (BQIW. Second

  12. Seasonal mercury concentrations and {delta}{sup 15}N and {delta}{sup 13}C values of benthic macroinvertebrates and sediments from a historically polluted estuary in south central Chile

    Energy Technology Data Exchange (ETDEWEB)

    Diaz-Jaramillo, Mauricio, E-mail: mdiazjaramillo@conicet.gov.ar [Aquatic Systems Research Unit, EULA Chile Environmental Sciences Centre, Universidad de Concepcion (Chile); Munoz, Claudia; Rudolph, Ignacio [Aquatic Systems Research Unit, EULA Chile Environmental Sciences Centre, Universidad de Concepcion (Chile); Servos, Mark [Department of Biology, University of Waterloo, ON (Canada); Barra, Ricardo [Aquatic Systems Research Unit, EULA Chile Environmental Sciences Centre, Universidad de Concepcion (Chile)

    2013-01-01

    The Lenga Estuary is one of the most industrialized sites in south central Chile where the historic operation of chlor-alkali plants resulted in large quantities of mercury (Hg) being deposited into the estuary. This historical contamination may still represent a risk to the biota in the estuary. To investigate this four macroinvertebrates, Neotrypaea uncinata (ghostshrimp), Elminius kingii (barnacle), Hemigrapsus crenulatus (shore crab) and Perinereis gualpensis (ragworm) were collected seasonally from three different sites in the Lenga Estuary and one in a reference estuary (Tubul Estuary), and analyzed for Hg and stable isotopes ({delta}{sup 15}N and {delta}{sup 13}C). Mercury concentrations in Lenga sediments ranged from 0.4 {+-} 0.1 to 13 {+-} 3 mg/kg, while those in Tubul sediments ranged from 0.02 {+-} 0.01 to 0.07 {+-} 0.09 mg/kg. Total Hg concentrations of invertebrates were significantly different between estuaries (p < 0.05), but not by species or season for each estuary (p > 0.05). In contrast, organic Hg concentrations were different by species and season with shore crab muscle tissues exhibiting the greatest percent difference. Site-specific relationships demonstrated that total Hg concentrations in ragworm best reflected the total Hg sediment mercury concentrations. Signatures of {delta}{sup 13}C were correlated to the organic Hg % rather than total Hg. This suggests that organic Hg concentrations in these species were related to the carbon sources. -- Highlights: Black-Right-Pointing-Pointer Hg in sediments and biota from Lenga Estuary were elevated compared to nearby estuary. Black-Right-Pointing-Pointer Invertebrates showed interspecific and seasonal differences in terms of organic Hg %. Black-Right-Pointing-Pointer Total Hg levels in the ragworm best reflect Hg sediment gradient in Lenga Estuary. Black-Right-Pointing-Pointer Interspecific variation in {delta}{sup 13}C signatures indicated different feeding modes. Black

  13. Rising from the ashes: Changes in salmonid fish assemblages after 30 months of the Puyehue-Cordon Caulle volcanic eruption.

    Science.gov (United States)

    Lallement, Mailén; Macchi, Patricio J; Vigliano, Pablo; Juarez, Santiago; Rechencq, Magalí; Baker, Matthew; Bouwes, Nicolaas; Crowl, Todd

    2016-01-15

    Events such as volcanic eruptions may act as disturbance agents modifying the landscape spatial diversity and increasing environmental instability. On June 4, 2011 the Puyehue-Cordon Caulle volcanic complex located on Chile (2236 m.a.s.l., 40° 02' 24" S- 70° 14' 26" W) experience a rift zone eruption ejecting during the first day 950 million metric tons into the atmosphere. Due to the westerly winds predominance, ash fell differentially upon 24 million ha of Patagonia Argentinean, been thicker deposits accumulated towards the West. In order to analyze changes on stream fish assemblages we studied seven streams 8, 19 and 30 months after the eruption along the ash deposition gradient, and compare those data to pre eruption ones. Habitat features and structure of the benthic macroinvertebrate food base of fish was studied. After the eruption, substantial environmental changes were observed in association with the large amount of ash fallout. In western sites, habitat loss due to ash accumulation, changes in the riparian zone and morphology of the main channels were observed. Turbidity was the water quality variable which reflected the most changes throughout time, with NTU values decreasing sharply from West to East sites. In west sites, increased Chironomid densities were recorded 8 months after the initial eruption as well as low EPT index values. These relationships were reversed in the less affected streams farther away from the volcano. Fish assemblages were greatly influenced both by habitat and macroinvertebrate changes. The eruption brought about an initial sharp decline in fish densities and the almost total loss of young of the year in the most western streams affecting recruitment. This effect diminished rapidly with distance from the emission center. Thirty months after the eruption, environmental changes are still occurring as a consequence of basin wide ash remobilization and transport. PMID:26473706

  14. Macroinvertebrate community responses to gravel augmentation in a high-gradient, Southeastern regulated river

    Energy Technology Data Exchange (ETDEWEB)

    McManamay, Ryan A [ORNL; Orth, Dr. Donald J [Virginia Polytechnic Institute and State University; Dolloff, Dr. Charles A [United States Department of Agriculture (USDA), United States Forest Service (USFS) and Virginia Pol

    2013-01-01

    Sediment transport, one of the key processes of river systems, is altered or stopped by dams, leaving lower river reaches barren of sand and gravel, both of which are essential habitat for fish and macroinvertebrates. One way to compensate for losses in sediment is to supplement gravel to river reaches below impoundments. Because gravel addition has become a widespread practice, it is essential to evaluate the biotic response to restoration projects in order to improve the efficacy of future applications. The purpose of our study was to evaluate the response of the macroinvertebrate community to gravel addition in a high-gradient, regulated river in western North Carolina. We collected benthic macroinvertebrate samples from gravel-enhanced areas and unenhanced areas for 1 season before gravel addition, and for 4 seasons afterwards. Repeated measures multivariate analysis of variance indicated that the responses of macroinvertebrates to gravel addition were generally specific to individual taxa or particular functional feeding groups and did not lead to consistent patterns in overall family richness, diversity, density, or evenness. Non-metric multi-dimensional scaling showed that shifts in macroinvertebrate community composition were temporary and dependent upon site conditions and season. Correlations between macroinvertebrate response variables and substrate microhabitat variables existed with or without the inclusion of data from enhanced areas, which suggests that substrate-biotic relationships were present before gravel addition. A review of the current literature suggests that the responses of benthic macroinvertebrates to substrate restoration are inconsistent and dependent upon site conditions and the degree habitat improvement of pre-restoration site conditions.

  15. Macroinvertebrados bentónicos como indicadores de calidad de agua de ríos del sur de Chile Benthic macroinvertebrates as indicators of water quality of southern Chile rivers

    Directory of Open Access Journals (Sweden)

    RICARDO FIGUEROA

    2003-06-01

    Full Text Available La Cuenca Hidrográfica del Río Damas (40°39' S, 72°23' O, presenta una intensa actividad agrícola y ganadera en un 78,2 % de su superficie, lo cual se ha traducido en importantes aportes de nutrientes al ecosistema acuático. Los objetivos de este estudio fueron: (a analizar la distribución espacial de la macrofauna bentónica en la cuenca y (b determinar la viabilidad de utilizar el Índice Biótico de Familias (IBF para evaluación de la calidad de las aguas. Los muestreos se realizaron en enero de 1998 con una red Surber (0,09 m², en 15 sitios distribuidos en el curso principal y sus tributarios. Se registró un total de 77 taxa, siendo los grupos más diversos Plecoptera (16 %, Trichoptera (16 %, Diptera (14 % y Ephemeroptera (12 %. Se observó una marcada tendencia a la disminución de riqueza específica desde la cabecera de la cuenca hacia aguas abajo. Las abundancias, biomasas y el IBF, presentaron una tendencia inversa a la riqueza específica. IBF se correlacionó significativa y positivamente con el fósforo total (r² = 0,71, temperatura (r² = 0,66, nitrito (r² = 0,56, conductividad eléctrica (r² = 0,50, demanda biológica de oxígeno (r² = 0,46 y nitrógeno total (r² = 0,46, y negativamente con oxígeno disuelto (r² = 0,53, variables estrechamente asociadas al uso intensivo de fertilizantes en la cuenca. Los resultados sugieren que el IBF es un buen indicador de la calidad de las aguas de los ríos de cuencas agrícolas y ganaderas del sur de ChileThe Damas River Hydrographic Basin (40°39'S, 72°23' W presents an intense agricultural and cattle ranching activities in 78.2 % of its surface, which has resulted in important inputs of nutrients into the aquatic ecosystem. The objectives of this study were: (a to analyze the spatial distribution of the benthic macrofauna in the Damas basin, and (b to determine the feasibility of using the Families Biotic Index (FBI for the evaluation of water quality. The samplings were

  16. Are macroinvertebrate functional traits useful in differentiating hydrologically variable small piedmont streams and their recovery from drought?

    Science.gov (United States)

    We quantified benthic macroinvertebrates in six small (1st order) Alabama piedmont streams from 1994-1998. Streams spanned a gradient of hydrologic permanence from typically intermittent to perennial, the degree of permanence for a given stream depending on water year. Initial sa...

  17. Benthic Cover

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — Benthic cover (habitat) maps are derived from aerial imagery, underwater photos, acoustic surveys, and data gathered from sediment samples. Shallow to...

  18. Alien macroinvertebrates in Flanders (Belgium)

    OpenAIRE

    Boets, Pieter; Brosens, Dimitri; Lock, Koen; Adriaens, Tim; Aelterman, Bart; Mertens, Joost; Goethals, Peter

    2016-01-01

    Biological invasions of aquatic macroinvertebrates are gaining interest because of their potential for significant ecological and socio-economic impacts (positive and negative). In the present study, an inventory was made of the alien macroinvertebrates occurring in Flanders (northern Belgium) based on extensive existing collections of biological samples and supplemented with our additional sampling programs. Fresh and brackish waters as well as the Belgian coastal harbours, situated at the i...

  19. Legacy of a Chemical Factory Site: Contaminated Groundwater Impacts Stream Macroinvertebrates

    DEFF Research Database (Denmark)

    Rasmussen, Jes J.; McKnight, Ursula S.; Sonne, Anne Thobo;

    2016-01-01

    data for many of the compounds occurring at contaminated sites. We studied the potential impact of a contaminated site, characterised by chlorinated solvents, sulfonamides, and barbiturates, on benthic macroinvertebrates in a receiving stream. Most of these compounds are characterised by low or unknown......Legislative and managing entities of EU member states face a comprehensive task because the chemical and ecological impacts of contaminated sites on surface waters must be assessed. The ecological assessment is further complicated by the low availability or, in some cases, absence of ecotoxicity...... primary inflow zone of the contaminated GW. Moreover, macroinvertebrate communities at these sampling sites could be distinguished from those at upstream control sites and sites situated along a downstream dilution gradient using multidimensional scaling. Importantly, macroinvertebrate indices currently...

  20. Cascading effects of flow reduction on the benthic invertebrate community in a lowland river

    DEFF Research Database (Denmark)

    Graeber, Daniel; Pusch, Martin T.; Lorenz, Stefan; Brauns, Mario

    2013-01-01

    Reduction of flow constitutes one of the most severe human alterations to rivers, as it affects the key abiotic feature of these ecosystems. While there has been considerable progress in understanding the effects of reduced flow on benthic macroinvertebrates, cascading effects of flow reduction on...... concentration minima of less than 5 mg l−1 which prevailed 74% of the days in summer. This depletion of DO after flow reduction presumably caused the observed species turnover. Hence, flow reduction in lowland rivers may not only directly impair the ecological functions provided by benthic macroinvertebrates...

  1. The effects of tricyclazole treatment on aquatic macroinvertebrates in the field and in laboratory

    Directory of Open Access Journals (Sweden)

    B. Rossaro

    2013-12-01

    Full Text Available The effects of tricyclazole treatments on benthic macroinvertebrates in the field and in laboratory were studied. In field conditions, low density of benthic populations was observed, both in treated and untreated plots, which was attributed to the short period of submersion of the rice field and high water temperature, fungicide treatments had no significant effect. Both laboratory acute toxicity test and a test using a mesocosm suggested a low toxicity of tricyclazole on invertebrates. A reduction of the macroinvertebrate density was observed only when tricyclazole concentration was applied at concentrations 100 times the ones tested in the field, acute toxicity test gave an LC50 after 48 h of 26 mg*L–1, in agreement with data obtained for other species.

  2. The influence of differing protected area status and environmental factors on the macroinvertebrate fauna of temperate austral wetlands

    Directory of Open Access Journals (Sweden)

    Toni Furlonge

    2015-07-01

    Full Text Available One means of conserving wetlands is to designate the area around them as ‘protected’. Although many different types of protected areas exist, ranging from international (Ramsar-listed to local importance, there is little information on how the type of protection influences biodiversity conservation. Studies of the effectiveness of protected area systems are a priority, if we are to understand their importance and design systems effectively. Many Tasmanian wetlands are regarded as having high to very high conservation values with more than 60% located within protected areas. This study tested macroinvertebrate richness and assemblage responses to a range of environmental attributes and differing types of protected area status at 66 protected Tasmanian (Australian wetlands. Two hundred and eighteen taxa were identified with an average of 33 species (or morphospecies and 18 families recorded per wetland. The wetland assemblages were idiosyncratic, four families contributed 21% of the total recorded and only two families contributed greater than 10%. Wetlands were not significantly nested on the basis of the composition of their macroinvertebrate assemblages. No single environmental attribute had a strong relationship with macroinvertebrate richness or assemblage composition and neither species richness nor assemblage composition varied significantly between different types of protected areas. Although the majority of protected area types were designed to support terrestrial conservation objectives rather than wetland values, our results suggest that the latter were also afforded protection. The state of the proximal zone (the terrestrial zone within 50m of the wetland edge and the type of aquatic habitat present (macrophyte or sediment-dominated substrates were the most important determinants of macroinvertebrate richness and assemblage composition across all types of protected wetlands. These results suggest that for temperate austral wetlands

  3. Evaluation of alternative macroinvertebrate sampling techniques for use in a new tropical freshwater bioassessment scheme

    OpenAIRE

    Isabel Eleanor Moore; Kevin Joseph Murphy

    2015-01-01

    Aim: The study aimed to determine the effectiveness of benthic macroinvertebrate dredge net sampling procedures as an alternative method to kick net sampling in tropical freshwater systems, specifically as an evaluation of sampling methods used in the Zambian Invertebrate Scoring System (ZISS) river bioassessment scheme. Tropical freshwater ecosystems are sometimes dangerous or inaccessible to sampling teams using traditional kick-sampling methods, so identifying an alternative procedure that...

  4. Water quality assessment using macroinvertebrates and physico-chemical parameters in the riverine system of Iligan City, Philippines

    OpenAIRE

    Annielyn D. Tampus; Ermelinda G. Tobias; Ruben F. Amparado; Lydia Bajo; Astrid L. Sinco

    2012-01-01

    The water quality in the riverine systems (Mandulog and Iligan) of Iligan City decreases as itapproaches the downstream. Canonical Correspondence Analysis (CCA) was used to determine whichphysico-chemical parameters would influence the assemblage of macroinvertebrates. Results revealedthat Total Suspended Solids (TSS) affect the groups Plecoptera, Tricoptera, Diptera and Simuliidae whilenitrate affects Plecoptera and Gomphidae. Principal Component Analysis (PCA) was used to determinewhich phy...

  5. Strange Assemblage

    Directory of Open Access Journals (Sweden)

    David Robert Cole

    2014-08-01

    Full Text Available This paper contends that the power of Deleuze & Guattari’s (1988 notion of assemblage as theorised in 1000 Plateaus can be normalised and reductive with reference to its application to any social-cultural context where an open system of dynamic and fluid elements are located. Rather than determining the assemblage in this way, this paper argues for an alternative conception of ‘strange assemblage’ that must be deliberately and consciously created through rigorous and focused intellectual, creative and philosophical work around what makes assemblages singular. The paper will proceed with examples of ‘strange assemblage’ taken from a film by Peter Greenaway (A Zed and 2 Noughts; the film ‘Performance’; educational research with Sudanese families in Australia; the book, Bomb Culture by Jeff Nuttall (1970; and the band Hawkwind. Fittingly, these elements are themselves chosen to demonstrate the concept of ‘strange assemblage’, and how it can be presented. How exactly the elements of a ‘strange assemblage’ come together and work in the world is unknown until they are specifically elaborated and created ‘in the moment’. Such spontaneous methodology reminds us of the 1960s ‘Happenings’, the Situationist International and Dada/Surrealism. The difference that will be opened up by this paper is that all elements of this ‘strange assemblage’ cohere in terms of a rendering of ‘the unacceptable.'

  6. Benthic macrofauna

    Digital Repository Service at National Institute of Oceanography (India)

    Ansari, Z.A.; Sivadas, S.; Ingole, B.S.

    in these waters has been empirically defined as animals retained by 0.5mm screens. Many organ- isms can thus be seen only on close inspection, while other may weigh several grams while fresh. Benthic macrofauna are good indicators of estuarine conditions because... they are relatively sedentary at the sediment?water interface and within deeper sediments (Dauer and Conner 1980). The abundance of benthic animals in an area is closely related to its environment and reflects the characteristics of an ecological niche (Ansari et al...

  7. Multi-Scalar Land Cover Influences on Benthic Invertebrate Assemblages in Agricultural Streams. F.B. Daniel, M.B. Griffith, M.E. Troyer, and J.E. Lazorchak Office of Research and Development, U.S. Environmental Protection Agency, Cincinnati, OH 45268

    Science.gov (United States)

    Daniel, F. B.; Griffith, M. B.; Troyer, M. E.; Lazorchak, J. E.

    2005-05-01

    The northern half of the Little Miami River watershed (LMRW) was graded by the Wisconsinan glacier; the southern half lies beyond the glacier terminus and is set in an older, Illinoisan landscape. Benthic invertebrates were collected in 35 headwater streams (sub-watersheds) in the LMRW for four consecutive years and the land cover was quantified at three spatial scales (the catchment, the riparian corridor, and sampled reach) for each sub-watershed. In the northern sub-watersheds (N=19) a significantly greater percentage of land surface is committed to row crop agriculture and significantly lesser percent is covered in permanent grasses or forest relative to those in the south (N=16). Analysis of the invertebrate samples showed that Ephemeroptera, Plecoptera, and Trichoptera (EPT) constituted a significantly greater proportion of those assemblages collected from the southern sub-watersheds compared to those from the northern section In contrast, Coleoptera (Cole) and Odonata (Odon) were significantly increased in the northern streams. Approximately 60 % of the variation in the invertebrate assemblages, e.g., the ratio of EPT/(EPT+Cole+Odon), at these sites can be accounted for by consideration of land cover at either the catchment or riparian scale but not at the reach scale.

  8. Structural and functional responses of benthic invertebrates to imidacloprid in outdoor stream mesocosms

    International Nuclear Information System (INIS)

    Structural and functional responses of a benthic macroinvertebrate assemblage to pulses of the insecticide imidacloprid were assessed in outdoor stream mesocosms. Imidacloprid pulses reduced invertebrate abundance and community diversity in imidacloprid-dosed streams compared to control streams. These results correlated well with effects of imidacloprid on leaf litter decomposition and feeding rates of Pteronarcys comstocki, a stonefly, in artificial streams. Reductions in oxygen consumption of stoneflies exposed to imidacloprid were also observed in laboratory experiments. Our findings suggest that leaf litter degradation and single species responses can be sensitive ecotoxicological endpoints that can be used as early warning indicators and biomonitoring tools for pesticide contamination. The data generated illustrates the value of mesocosm experiments in environmental assessment and how the consideration of functional and structural endpoints of natural communities together with in situ single species bioassays can improve the evaluation and prediction of pesticide effects on stream ecosystems. - Combining organism-level responses with community-level processes for the evaluation and prediction of pesticide effects on stream ecosystems.

  9. Depauperate macroinvertebrates in a mine affected stream: Clean water may be the key to recovery

    International Nuclear Information System (INIS)

    Acid mine drainage (AMD) is frequently linked with changes in macroinvertebrate assemblages, but the relative contribution of water and sediment to toxicity is equivocal. We have shown that the macroinvertebrate fauna of Neubecks Ck, a mine impacted stream in New South Wales, Australia, was much poorer than in two reference streams. Multivariate RELATE analyses indicated that the patterns in the biological data were more strongly correlated with the concentrations of common metals in the surface water than the pore water of these streams. From this we hypothesised that the water was more toxic to the biota than the sediment and we tested this hypothesis with a sediment transplant experiment. Sediment from Neubecks Ck that was placed in reference streams retained high concentrations of metals throughout the experiment, yet supported a macroinvertebrate assemblage similar to that in the reference streams. Sediment from the reference streams that was placed in Neubecks Ck supported few, if any, animals. This indicates that water in Neubecks Ck is toxic to biota, but that sediment is able to support aquatic biota in clean water. Therefore, remediation should focus on improving water quality rather than sediment quality. - Macroinvertebrates colonise contaminated sediment in clean water

  10. Change does not happen overnight: a case study on stream macroinvertebrates

    Directory of Open Access Journals (Sweden)

    Guareschi S.

    2016-01-01

    Full Text Available The influence of day/night conditions on individual animal/plant species has been widely studied, but diel cycle studies of the entire stream macroinvertebrate community are extremely rare. This study explored potential dissimilarities between daytime and nighttime macroinvertebrate assemblages by extensive fieldwork conducted in the Lemme stream, a natural water course of NW Italy. Here numerous structural and functional metrics (richness, abundance, biomass, indicator taxa, composition, biomonitoring values and feeding groups were evaluated at the family level. Small-scale environmental variables were investigated to understand possible differences between macroinvertebrate assemblages in the daytime/nighttime. After collecting and identifying 21 459 organisms of 50 taxa, Chironomidae (Diptera was the most abundant under both day and night conditions. Our findings stressed that similar results and biological information on daytime/nighttime data were obtained. No marked differences could be related to various factors: heterotrophic condition of small-order streams, presence of aquatic predators under night and day conditions, absence of taxa with a specific phototaxis. Of all the environmental variables, velocity was always the most important in both situations, with some differences detected in the importance of the second variable (riverbed substrate diameter. This research, and future studies on different conditions and geographic areas, will contribute knowledge on stream macroinvertebrate diel activity, and provide useful information about efficient sampling strategies.

  11. Biodiversity patterns of macrophyte and macroinvertebrate communities in two lagoons of Western Greece.

    Science.gov (United States)

    Fyttis, G.; Reizopoulou, S.; Papastergiadou, E.

    2012-04-01

    Aquatic macrophytes and benthic macroinvertebrates were studied seasonally (Spring, Autumn, Summer) between the years 2009 - 2011 in two coastal lagoons (Kotychi and Prokopos) located in Peloponnese, Greece, in order to investigate spatial and temporal biodiversity trends related to hydrological processes (degree of confinement, nitrates, phosphates, chl-a, total suspended materials, light irradiance, pH, salinity, temperature and dissolved oxygen). Kotychi lagoon presents a better communication with the sea, while Prokopos has a high degree of confinement. Both ecosystems seasonally receive freshwater input from streams. The submerged aquatic macrophytes constituted a major component of the ecosystems studied. In total, 22 taxa of aquatic macrophytes (angiosperms and macroalgae), 16 taxa for Kotychi (2 Rhodophyta, 8 Chlorophyta, 5 Magnoliophyta, 1 Streptophyta) and 14 taxa for Prokopos (1 Rhodophyta, 5 Chlorophyta, 5 Magnoliophyta, 3 Streptophyta) were found. Ruppia cirrhosa, and Potamogeton pectinatus were dominant in both lagoons. Kotychi lagoon was also dominated by Zostera noltii and Prokopos by Zannichellia pallustris ssp. pedicellata, while the biomass of aquatic species peaked during the summer periods, in both lagoons. The total number of macroinvertebrates found in the lagoons was 28 taxa for Kotychi and 19 for Prokopos. Chironomidae were dominant in both lagoons, while Kotychi was also dominated by Lekanesphaera monodi and Monocorophium insidiosum, and Prokopos by Ostracoda and Lekanesphaera monodi. Benthic diversity ranged from 1.33 to 2.57 in Kotychi and from 0.67 to 2.48 in Prokopos. Species richness, diversity, and abundance of benthic macroinvertebrates were strongly related to aquatic vegetation and to the degree of communication with the marine environment. Moreover, species richness and abundance of both macrophytes and macroinvertebrates were mainly dependent on depth, temperature, pH and concentration of total suspended materials (TSM). Results

  12. 2010 NCCA oligochaete trophic index results to inform benthic index development for the Great Lakes

    Science.gov (United States)

    Over 400 sites were sampled in the nearshore of the U.S. Great Lakes during the National Coastal Condition Assessment (NCCA) field survey in summer 2010. To assess benthic ecological condition, 393 PONARs were attempted, and collected macroinvertebrates were identified and enume...

  13. Benthic foraminifera

    Digital Repository Service at National Institute of Oceanography (India)

    Saraswat, R.; Nigam, R.

    Paula, Goa, India (For Correspondence: rsaraswat@nio.org) (Modified after Paul Loubre# and William Austin$) # Department of Geology and Environmental Geosciences, Davis Hall, Northern Illinois University, DeKalb, Illinois 60115 USA $ School... and trochospiral forms) (Figure 1). The external surface of the shell is often ornamented with pits, ribs, spines, plates, etc. The benthic foraminifers communicate with the surrounding environment through an opening in the shell, called as aperture. A web...

  14. Weak concordance between fish and macroinvertebrates in Mediterranean streams.

    Directory of Open Access Journals (Sweden)

    Stefano Larsen

    Full Text Available Although anthropogenic degradation of riverine systems stimulated a multi-taxon bioassessment of their ecological integrity in EU countries, specific responses of different taxonomic groups to human pressure are poorly investigated in Mediterranean rivers. Here, we assess if richness and composition of macroinvertebrate and fish assemblages show concordant variation along a gradient of anthropogenic pressure in 31 reaches across 13 wadeable streams in central Italy. Fish and invertebrate taxonomic richness was not correlated across sites. However, Mantel test showed that the two groups were significantly, albeit weakly, correlated even after statistically controlling for the effect of environmental variables and site proximity. Variance partitioning with partial Canonical Correspondence Analysis showed that the assemblages of the two groups were influenced by different set of environmental drivers: invertebrates were influenced by water organic content, channel and substratum features, while fish were related to stream temperature (mirroring elevation and local land-use. Variance partitioning revealed the importance of biotic interactions between the two groups as a possible mechanisms determining concordance. Although significant, the congruence between the groups was weak, indicating that they should not be used as surrogate of each other for environmental assessments in these Mediterranean catchments. Indeed, both richness and patterns in nestedness (i.e. where depauperate locations host only a subset of taxa found in richer locations appeared influenced by different environmental drivers suggesting that the observed concordance did not result from a co-loss of taxa along similar environmental gradients. As fish and macroinvertebrates appeared sensitive to different environmental factors, we argue that monitoring programmes should consider a multi-assemblage assessment, as also required by the Water Framework Directive.

  15. Uppermost Jurassic to Lower Cretaceous benthic foraminiferal biostratigraphy at ODP Site 765 on the Argo Abyssal Plain.

    OpenAIRE

    Kaminski, M.A.; Gradstein, F.M.; Geroch, S.

    1992-01-01

    Benthic foraminifers were studied in 99 samples collected from the lower 200 m of Hole 765C. The studied section ranges from the Tithonian to Aptian, and benthic foraminifers can be subdivided into five assemblages on the basis of faunal diversity and stratigraphic ranges of distinctive species. Compared with deep-water assemblages from Atlantic DSDP sites and Poland, assemblages from the Argo Abyssal Plain display a higher diversity of agglutinated forms, which comprise the autochthonous ...

  16. Evaluating macroinvertebrate community shifts in the confluence of freestone and limestone streams

    Directory of Open Access Journals (Sweden)

    Jennifer K. Hellmann

    2014-07-01

    Full Text Available Aquatic macroinvertebrates are critical to ecosystem functioning through their regulation of many essential top-down and bottom-up ecosystem processes such as energy translocation, nutrient flow, and detrital decomposition. However, specific preferences by macroinvertebrates for certain ranges of abiotic and biotic characteristics mean that changes in these factors often create large differences in benthic community structure. Investigations into drivers of community structure have found distinct patterns of variation between ecosystems, but drivers of macroscale variation may differ from drivers of microscale variation. Such microscale variation in macroinvertebrate community structure as a function of abiotic conditions may be found in the confluence of two geologically distinct freshwater streams. Variation in the origin, underlying bedrock, and watershed of a stream results in drastically different physical and chemical characteristics and correspondingly distinct macroinvertebrate community structures. In areas where water from geologically distinct streams flows together, a mixing zone emerges with unique chemical and physical characteristics. There is little information on how invertebrate communities are structured within this mixing zone. To investigate this, we examined how the structure of the macroinvertebrate community changed downstream of the confluence. Up to thirty metres downstream, we found distinct stream sections that mirrored physical and chemical conditions found in limestone and freestone streams, and a mixing zone with emergent properties. These physical and chemical changes between sites were accompanied by shifts in macroinvertebrate community composition. Diversity indices indicated significantly higher diversity in freestone sites than in limestone sites or the mixing zone and there was a unique composition of genera in the mixing zone that were distinct from both limestone and freestone sites. Factors driving

  17. Macroinvertebrate community structure and function along gradients of physical stream quality and pesticide contamination in Danish streams

    DEFF Research Database (Denmark)

    Rasmussen, Jes

      A wide array of pesticides are applied to agricultural crops during spring and autumn spraying season, and detections of pesticides in stream water and bed sediments of agricultural streams emphasize the potential exposure of benthic macroinvertebrates. Major transportation routes from catchment...... to stream are surface runoff and tile drainage giving rise to short pulses of acute contamination strongly coinciding with high levels of precipitation. Field studies indicate that macroinvertebrate community structure can be impacted by pesticides during spraying seasons in May and June, but also...... pesticide concentrations in each stream were measured applying sediment sampling and event triggered water samplers. Furthermore, on all reaches macroinvertebrate community structure was assessed before, during and after the spring application season. Stream reaches with good physical quality generally...

  18. Biological traits of European pond macroinvertebrates

    OpenAIRE

    Céréghino, Régis; Oertli, Beat; Marcello BAZZANTI; Coccia, Cristina; Compin, Arthur; Biggs, Jeremy; Bressi, Nicolas; Grillas, Patrick; Hull, Andrew P.; Kalettka, Thomas; Scher, Olivier

    2012-01-01

    Whilst biological traits of river macroinvertebrates show unimodal responses to geographic changes in habitat conditions in Europe, we still do not know whether spatial turnover of species result in distinct combinations of biological traits for pond macroinvertebrates. Here, we used data on the occurrence of 204 macroinvertebrate taxa in 120 ponds from four biogeographic regions of Europe, to compare their biological traits. The Mediterranean, Atlantic, Alpine, and Continental regions have s...

  19. Coal-tar based pavement sealant toxicity to freshwater macroinvertebrates

    Energy Technology Data Exchange (ETDEWEB)

    Bryer, P.J.; Scoggins, M.; McClintock, N.L. [Lamar University, Beaumont, TX (United States). Dept. of Biology

    2010-05-15

    Non-point-source pollution is a major source of ecological impairment in urban stream systems. Recent work suggests that coal-tar pavement sealants, used extensively to protect parking areas, may be contributing a large portion of the polycyclic aromatic hydrocarbon (PAH) loading seen in urban stream sediments. The hypothesis that dried coal-tar pavement sealant flake could alter the macroinvertebrate communities native to streams in Austin, TX was tested using a controlled outdoor laboratory type approach. The treatment groups were: control, low, medium, and high with total PAH concentrations (TPAH = sum of 16 EPA priority pollutant PAHs) of 0.1, 7.5, 18.4, & 300 mg/kg respectively. The low, medium, and high treatments were created via the addition of dried coal-tar pavement sealant to a sterile soil. At the start of the 24-day exposure, sediment from a minimally impacted local reference site containing a community of live sediment-dwelling benthic macroinvertebrates was added to each replicate. An exposure-dependent response was found for several stream health measures and for several individual taxa. There were community differences in abundance (P = 0.0004) and richness (P < 0.0001) between treatments in addition to specific taxa responses, displaying a clear negative relationship with the amount of coal-tar sealant flake. These results support the hypothesis that coal-tar pavement sealants contain bioavailable PAHs that may harm aquatic environments.

  20. Coal-tar based pavement sealant toxicity to freshwater macroinvertebrates

    International Nuclear Information System (INIS)

    Non-point-source pollution is a major source of ecological impairment in urban stream systems. Recent work suggests that coal-tar pavement sealants, used extensively to protect parking areas, may be contributing a large portion of the polycyclic aromatic hydrocarbon (PAH) loading seen in urban stream sediments. The hypothesis that dried coal-tar pavement sealant flake could alter the macroinvertebrate communities native to streams in Austin, TX was tested using a controlled outdoor laboratory type approach. The treatment groups were: control, low, medium, and high with total PAH concentrations (TPAH = sum of 16 EPA priority pollutant PAHs) of 0.1, 7.5, 18.4, and 300 mg/kg respectively. The low, medium, and high treatments were created via the addition of dried coal-tar pavement sealant to a sterile soil. At the start of the 24-day exposure, sediment from a minimally impacted local reference site containing a community of live sediment-dwelling benthic macroinvertebrates was added to each replicate. An exposure-dependent response was found for several stream health measures and for several individual taxa. There were community differences in abundance (P = 0.0004) and richness (P < 0.0001) between treatments in addition to specific taxa responses, displaying a clear negative relationship with the amount of coal-tar sealant flake. These results support the hypothesis that coal-tar pavement sealants contain bioavailable PAHs that may harm aquatic environments. - Coal-tar pavement sealants degrade stream invertebrate communities.

  1. Macroinvertebrates of the Iranian running waters: a review

    Directory of Open Access Journals (Sweden)

    Moslem Sharifinia

    2015-12-01

    Full Text Available Abstract A comprehensive review of macroinvertebrate studies conducted along the Iranian running waters over the last 15 years has been made by providing the most updated checklist of the Iranian running waters benthic invertebrates. Running waters ecosystems are complex environments known for their importance in terms of biodiversity. As part of the analysis, we endeavored to provide the critical re-identification of the reported species by through comparisons with the database of the Animal Diversity Web (ADW and appropriate literature sources or expert knowledge. A total of 126 species belonging to 4 phyla have been compiled from 57 references. The phylum Arthropoda was found to comprise the most taxa (n = 104 followed by Mollusca, Annelida and Platyhelminthes. Ongoing efforts in the Iranian running waters regarding biomonitoring indices development, testing, refinement and validation are yet to be employed in streams and rivers. Overall, we suggest that future macroinvertebrate studies in Iranian running waters should be focused on long-term changes by broadening target species and strong efforts to publish data in peer-reviewed journals in English.

  2. Recovery of lotic macroinvertebrate communities from disturbance

    Science.gov (United States)

    Wallace, J. Bruce

    1990-09-01

    Ecosystem disturbances produce changes in macrobenthic community structure (abundances, biomass, and production) that persist for a few weeks to many decades. Examples of disturbances with extremely long-term effects on benthic communities include contamination by persistent toxic agents, physical changes in habitats, and altered energy inputs. Stream size, retention, and local geomorphology may ameliorate the influence of disturbances on invertebrates. Disturbances can alter food webs and may select for favorable genotypes (e.g., insecticidal resistance). Introductions of pesticides into lotic ecosystems, which do not result in major physical changes within habitats, illustrate several factors that influence invertebrate recovery time from disturbance. These include: (1) magnitude of original contamination, toxicity, and extent of continued use; (2) spatial scale of the disturbance; (3) persistence of the pesticide; (4) timing of the contamination in relation to the life history stages of the organisms; (5) vagility of populations influenced by pesticides; and (6) position within the drainage network. The ability of macroinvertebrates to recolonize denuded stream habitats may vary greatly depending on regional life histories, dispersal abilities, and position within the stream network (e.g., headwaters vs larger rivers). Although downstream drift is the most frequently cited mechanism of invertebrate recolonization following disturbance in middle- and larger-order streams, evidence is presented that shows aerial recolonization to be potentially important in headwater streams. There is an apparent stochastic element operating for aerial recolonization, depending on the timing of disturbance and flight periods of various taxa. Available evidence indicates that recolonization of invertebrate taxa without an aerial adult stage requires longer periods of time than for those that possess winged, terrestrial adult stages (i.e., most insects). Innovative, manipulative

  3. On the benthic molluscs of Banco Inglés (Río de la Plata, Uruguay

    Directory of Open Access Journals (Sweden)

    Carranza, A.

    2007-12-01

    Full Text Available We describe the specific richness and community structure of benthic molluscs on a shallow-water sandy bank (Banco Inglés in the Río de la Plata estuary. From a total of 25 macroinvertebrate taxa collected, that included one ophiuroid, one bryozoan, fourcrustaceans and four polychaete species, molluscs were the dominant taxon, with 15 species recorded. These were one species of Polyplacophora, eight Bivalvia and six Gastropoda (one exotic, representing 11families and 11 genera. In terms of mean relative abundance, the molluscan assemblage was dominated by the deposit-feeder bivalve Corbula caribaea, averaging ca. 30% of the individuals of the macroinfauna. The alien species Rapana venosa was noted in two stations, represented by one and four specimens. We used null model analysis to test for nonrandomness in the structure of the molluscan communities of the area. The analysis supported the null hypothesis that co-occurrence patterns could not be distinguished from those that might arise by random processes.

  4. Bottom fish assemblages at the shelf and continental slope off East Greenland

    DEFF Research Database (Denmark)

    Jørgensen, Ole A; Hvingel, Carsten; Møller, P.R.

    2015-01-01

    benthic species were used for analyses of the fish fauna diversity and fish assemblages. Nine assemblages were found by a standard type of cluster analysis. A Bayesian multinomial logit model was then applied to calculate vectors of probabilities defining the likelihood of each haul belonging to each...

  5. Evaluation of Macroinvertebrate Communities and Habitat for Selected Stream Reaches at Los Alamos National Laboratory

    Energy Technology Data Exchange (ETDEWEB)

    L.J. Henne; K.J. Buckley

    2005-08-12

    This is the second aquatic biological monitoring report generated by Los Alamos National Laboratory's (LANL's) Water Quality and Hydrology Group. The study has been conducted to generate impact-based assessments of habitat and water quality for LANL waterways. The monitoring program was designed to allow for the detection of spatial and temporal trends in water and habitat quality through ongoing, biannual monitoring of habitat characteristics and benthic aquatic macroinvertebrate communities at six key sites in Los Alamos, Sandia, Water, Pajarito, and Starmer's Gulch Canyons. Data were collected on aquatic habitat characteristics, channel substrate, and macroinvertebrate communities during 2001 and 2002. Aquatic habitat scores were stable between 2001 and 2002 at all locations except Starmer's Gulch and Pajarito Canyon, which had lower scores in 2002 due to low flow conditions. Channel substrate changes were most evident at the upper Los Alamos and Pajarito study reaches. The macroinvertebrate Stream Condition Index (SCI) indicated moderate to severe impairment at upper Los Alamos Canyon, slight to moderate impairment at upper Sandia Canyon, and little or no impairment at lower Sandia Canyon, Starmer's Gulch, and Pajarito Canyon. Habitat, substrate, and macroinvertebrate data from the site in upper Los Alamos Canyon indicated severe impacts from the Cerro Grande Fire of 2000. Impairment in the macroinvertebrate community at upper Sandia Canyon was probably due to effluent-dominated flow at that site. The minimal impairment SCI scores for the lower Sandia site indicated that water quality improved with distance downstream from the outfall at upper Sandia Canyon.

  6. Assessment of impact of geochemical and environmental properties on the meiofauna (benthic foraminifer, ostracod, mollusc) assemblages: A case study in The Late Quaternary Sediments In The Gulf Of Izmir (Eastern Aegean Sea)

    Science.gov (United States)

    Yümün, Zeki Ü.

    2016-04-01

    The drilling samples collected from varying depths at 1.00-13.00 m at four different localities of Karsiyaka, Bayrakli, Inciralti and Urla (Çesmealti) in the Gulf of Izmir were studied for their geochemical, sedimantological and micropaleontological properties. The purpose of this study is to describe the meiofauna of the sediments, to determine the pollution history of the gulf and to show the effect of the pollution on the foraminifera and ostracoda. Examination of the loose sediments reveals that the gulf has been affected by the sea for a long time, and it had a rich microfaunal assemblages. Both foraminiferal tests and ostracod carapaces have coloring, and morphological abnormalities have been determined in foraminiferal tests. Peneroplis pertusus (Forskal) and P. planatus (Fichtel and Moll) have blue and black colored tests, while morphological abnormalities were observed on the tests of Ammonia compacta Hofker, Elphidium complanatum (d'Orbigny), E. crispum (Linné), E. macellum (Fichtel and Moll). The ostracod carapaces are generally gray-black colored. Heavy metal (Cr, Mn, Zn, Co, Ni, Cu) analyses have been carried out on the sediments of the Gulf of Izmir. Heavy metal concentrations are high in Bayrakli, and low in Urla (Çesmealti). Cr, Mn and Zn values are the highest in Bayrakli, whereas Co, Ni and Cu values are the highest in Inciralti. Scanning Electron Microscope (SEM) analyses were performed and no heavy metal was detected on the white and colored ostracod carapaces. When the white and colored ostracod carapaces are compared, the coloured ostracode carapace has higher Mg content, and also includes Fe, Al, N, Cl and K. Based on the results obtained, it is observed that the Bayrakli region have been more affected by the pollution than Urla (Çesmealti).

  7. Responses of epibenthic and nektonic macroinvertebrate communities to a gradient of fish size in ponds

    Directory of Open Access Journals (Sweden)

    Marek Nieoczym

    2014-07-01

    Full Text Available Size relationships between fish and organisms from adjacent trophic levels are crucial for predicting the structure and dynamics of aquatic ecosystems. We compared macroinvertebrate communities along a fish-size gradient created by separate stocking of three age cohorts of common carp Cyprinus carpio in semi-natural ponds. The specific size range of fish (small, medium and large corresponding to fish age in ponds was the factor most strongly associated with macroinvertebrate composition. The other significant habitat variables were dissolved oxygen concentration in the water and submerged vegetation abundance in the open-water zone. Among the most numerous taxa in the ponds, relative abundances of Hirudinea, Gastropoda, Odonata and Coleoptera were larger in the presence of small-sized than of larger-sized carp. However, fish size effect was not linear, in that macroinvertebrate assemblages were less similar between ponds containing medium- vs large-sized fish than between ponds with small- vs large-sized fish. The dissimilarity patterns were mainly determined by disparities in abundance of Corixidae, which unlike other taxa common in the ponds occurred in the greatest numbers in the presence of large-sized carp. Macroinvertebrate diversity was greatest in ponds with small-sized fish and was positively related to emergent macrophyte cover. Enhancement of emergent vegetation is recommended as the most effective management strategy to buffer adverse impacts of fish on macroinvertebrates. If fish are present in the system, assessment of the size structure of fish populations can be advantageous in unravelling the essential processes driving the variation in pond communities.

  8. Structure of Benthic Communities along the Taiwan Latitudinal Gradient.

    Science.gov (United States)

    Ribas-Deulofeu, Lauriane; Denis, Vianney; De Palmas, Stéphane; Kuo, Chao-Yang; Hsieh, Hernyi Justin; Chen, Chaolun Allen

    2016-01-01

    The distribution and the structure of benthic assemblages vary with latitude. However, few studies have described benthic communities along large latitudinal gradients, and patterns of variation are not fully understood. Taiwan, lying between 21.90°N and 25.30°N, is located at the center of the Philippine-Japan arc and lies at the northern margin of coral reef development. A wide range of habitats is distributed along this latitudinal gradient, from extensive fringing coral reefs at the southern coast to non-reefal communities at the north. In this study, we examined the structure of benthic communities around Taiwan, by comparing its assemblages in four regions, analyzing the effects of the latitudinal gradient, and highlighting regional characteristics. A total of 25 sites, 125 transects, and 2,625 photographs were used to analyze the benthic communities. Scleractinian corals present an obvious gradient of increasing diversity from north to south, whereas macro-algae diversity is higher on the north-eastern coast. At the country scale, Taiwanese coral communities were dominated by turf algae (49%). At the regional scale, we observed an important heterogeneity that may be caused by local disturbances and habitat degradation that smooths out regional differences. In this context, our observations highlight the importance of managing local stressors responsible for reef degradation. Overall, this study provides an important baseline upon which future changes in benthic assemblages around Taiwan can be assessed. PMID:27513665

  9. Sediment Burial Intolerance of Marine Macroinvertebrates.

    Science.gov (United States)

    Hendrick, Vicki J; Hutchison, Zoë L; Last, Kim S

    2016-01-01

    The marine environment contains suspended particulate matter which originates from natural and anthropogenic sources. Settlement of this material can leave benthic organisms susceptible to smothering, especially if burial is sudden i.e. following storms or activities such as dredging. Their survival will depend on their tolerance to, and their ability to escape from burial. Here we present data from a multi-factorial experiment measuring burial responses incorporating duration, sediment fraction and depth. Six macroinvertebrates commonly found in sediment rich environments were selected for their commercial and/or conservation importance. Assessments revealed that the brittle star (Ophiura ophiura), the queen scallop (Aequipecten opercularis) and the sea squirt (Ciona intestinalis) were all highly intolerant to burial whilst the green urchin (Psammichinus miliaris) and the anemone (Sagartiogeton laceratus), showed intermediate and low intolerance respectively, to burial. The least intolerant, with very high survival was the Ross worm (Sabellaria spinulosa). With the exception of C. intestinalis, increasing duration and depth of burial with finer sediment fractions resulted in increased mortality for all species assessed. For C. intestinalis depth of burial and sediment fraction were found to be inconsequential since there was complete mortality of all specimens buried for more than one day. When burial emergence was assessed O. ophiura emerged most frequently, followed by P. miliaris. The former emerged most frequently from the medium and fine sediments whereas P. miliaris emerged more frequently from coarse sediment. Both A. opercularis and S. laceratus showed similar emergence responses over time, with A. opercularis emerging more frequently under coarse sediments. The frequency of emergence of S. laceratus increased with progressively finer sediment and C. intestinalis did not emerge from burial irrespective of sediment fraction or depth. Finally, and perhaps

  10. Sediment Burial Intolerance of Marine Macroinvertebrates.

    Directory of Open Access Journals (Sweden)

    Vicki J Hendrick

    Full Text Available The marine environment contains suspended particulate matter which originates from natural and anthropogenic sources. Settlement of this material can leave benthic organisms susceptible to smothering, especially if burial is sudden i.e. following storms or activities such as dredging. Their survival will depend on their tolerance to, and their ability to escape from burial. Here we present data from a multi-factorial experiment measuring burial responses incorporating duration, sediment fraction and depth. Six macroinvertebrates commonly found in sediment rich environments were selected for their commercial and/or conservation importance. Assessments revealed that the brittle star (Ophiura ophiura, the queen scallop (Aequipecten opercularis and the sea squirt (Ciona intestinalis were all highly intolerant to burial whilst the green urchin (Psammichinus miliaris and the anemone (Sagartiogeton laceratus, showed intermediate and low intolerance respectively, to burial. The least intolerant, with very high survival was the Ross worm (Sabellaria spinulosa. With the exception of C. intestinalis, increasing duration and depth of burial with finer sediment fractions resulted in increased mortality for all species assessed. For C. intestinalis depth of burial and sediment fraction were found to be inconsequential since there was complete mortality of all specimens buried for more than one day. When burial emergence was assessed O. ophiura emerged most frequently, followed by P. miliaris. The former emerged most frequently from the medium and fine sediments whereas P. miliaris emerged more frequently from coarse sediment. Both A. opercularis and S. laceratus showed similar emergence responses over time, with A. opercularis emerging more frequently under coarse sediments. The frequency of emergence of S. laceratus increased with progressively finer sediment and C. intestinalis did not emerge from burial irrespective of sediment fraction or depth. Finally

  11. Spray drift of pesticides and stream macroinvertebrates: Experimental evidence of impacts and effectiveness of mitigation measures

    International Nuclear Information System (INIS)

    Impoverished stream communities in agricultural landscapes have been associated with pesticide contamination, but conclusive evidence of causality is rare. We address this deficiency by adopting an experimental approach to investigate the effects of the insecticides cypermethrin and chlorpyrifos on benthic macroinvertebrates. Three treatments were established and a combination of biomarker, bioassay and biomonitoring approaches was employed to investigate, individual, population and community-level effects. Animals deployed during pesticide application had altered enzyme activity, depressed feeding rate and reduced survival, but these effects were only observed where pesticide was sprayed to the stream edge. There were no clear pesticide-related effects on macroinvertebrate community structure or on the population densities of individual species. Hence, short-term pesticide exposure did cause individual-level effects in stream macroinvertebrates, but these were not translated to effects at the population or community-level and were effectively mitigated by the adoption of a no-spray buffer zone. - Pulsed pesticide exposures via spray drift adversely affected stream invertebrates but did not cause population or community-level effects and were mitigated by no-spray buffer zones

  12. Legacy of a Chemical Factory Site: Contaminated Groundwater Impacts Stream Macroinvertebrates.

    Science.gov (United States)

    Rasmussen, Jes J; McKnight, Ursula S; Sonne, Anne Th; Wiberg-Larsen, Peter; Bjerg, Poul L

    2016-02-01

    Legislative and managing entities of EU member states face a comprehensive task because the chemical and ecological impacts of contaminated sites on surface waters must be assessed. The ecological assessment is further complicated by the low availability or, in some cases, absence of ecotoxicity data for many of the compounds occurring at contaminated sites. We studied the potential impact of a contaminated site, characterised by chlorinated solvents, sulfonamides, and barbiturates, on benthic macroinvertebrates in a receiving stream. Most of these compounds are characterised by low or unknown ecotoxicity, but they are continuously discharged into the stream by way of a long-lasting source generating long-term chronic exposure of the stream biota. Our results show that taxonomical density and diversity of especially sediment dwelling taxa were reduced by >50 % at the sampling sites situated in the primary inflow zone of the contaminated GW. Moreover, macroinvertebrate communities at these sampling sites could be distinguished from those at upstream control sites and sites situated along a downstream dilution gradient using multidimensional scaling. Importantly, macroinvertebrate indices currently used did not identify this impairment, thus underpinning an urgent need for developing suitable tools for the assessment of ecological effects of contaminated sites in streams. PMID:26276033

  13. The effect of an industrial effluent on an urban stream benthic community: water quality vs. habitat quality

    International Nuclear Information System (INIS)

    Discharges that affect both water quality and habitat quality can have complex effects on flowing water communties. - We studied the effect of an industrial effluent on the water quality, habitat quality, and benthic macroinvertebrates of an urban stream in southwestern Michigan (USA). The effluent affected water quality by raising in-stream temperatures 13-18 deg. C during colder months and carrying high amounts of iron (>20xhigher than ambient) that covered the streambed. The effluent also affected habitat conditions by increasing total stream discharge by 50-150%, causing a significant change in substrate and flow conditions. We used three methods to collect benthic macroinvertebrates in depositional and erosional habitats and to understand the relative importance of habitat quality and water quality alterations. Macroinvertebrate response variables included taxonomic richness, abundance, and proportional abundance of sensitive taxonomic groups. Results indicated that the effluent had a positive effect on macroinvertebrate communities by increasing the quantity of riffle habitat, but a negative effect on macroinvertebrate communities by reducing water quality. Results illustrated the need for careful consideration of habitat quality and water quality in restoration or remediation programs

  14. Differences Found in the Macroinvertebrate Community Composition in the Presence or Absence of the Invasive Alien Crayfish, Orconectes hylas.

    Science.gov (United States)

    Freeland-Riggert, Brandye T; Cairns, Stefan H; Poulton, Barry C; Riggert, Christopher M

    2016-01-01

    Introductions of alien species into aquatic ecosystems have been well documented, including invasions of crayfish species; however, little is known about the effects of these introductions on macroinvertebrate communities. The woodland crayfish (Orconectes hylas (Faxon)) has been introduced into the St. Francis River watershed in southeast Missouri and has displaced populations of native crayfish. The effects of O. hylas on macroinvertebrate community composition were investigated in a fourth-order Ozark stream at two locations, one with the presence of O. hylas and one without. Significant differences between sites and across four sampling periods and two habitats were found in five categories of benthic macroinvertebrate metrics: species richness, percent/composition, dominance/diversity, functional feeding groups, and biotic indices. In most seasons and habitat combinations, the invaded site had significantly higher relative abundance of riffle beetles (Coleoptera: Elmidae), and significantly lower Missouri biotic index values, total taxa richness, and both richness and relative abundance of midges (Diptera: Chironomidae). Overall study results indicate that some macroinvertebrate community differences due to the O. hylas invasion were not consistent between seasons and habitats, suggesting that further research on spatial and temporal habitat use and feeding ecology of Ozark crayfish species is needed to improve our understanding of the effects of these invasions on aquatic communities. PMID:26986207

  15. Long-Term Changes in the Water Quality and Macroinvertebrate Communities of a Subtropical River in South China

    Directory of Open Access Journals (Sweden)

    Kun Li

    2014-12-01

    Full Text Available Subtropical rivers support a highly diverse array of benthic macroinvertebrates. In this study, by combining historical data and new data, we identified specific changes in the Guanlan River, in South China, from 1981 to 2011, and evaluated the effectiveness of an ecological restoration project under highly polluted conditions. From 1981 to 2011, the water quality in the Guanlan River underwent three major stages. With the deterioration of water quality, there was an overall decrease in the species number of macroinvertebrates in the Guanlan River, an increase in macroinvertebrate density, and a reduction of the biodiversity, and a reduction of functional feeding groups. In 2011, after five years of comprehensive remediation, the Guanlan River was somewhat improved. Macroinvertebrate biodiversity in the middle reach of the Guanlan River, where a key ecological restoration engineering project was implemented, did not differ significantly from other sites. This finding indicates that the effectiveness of ecological restoration measures in highly polluted rivers, particularly at the reach-scale, is very limited and even ineffective.

  16. Differences Found in the Macroinvertebrate Community Composition in the Presence or Absence of the Invasive Alien Crayfish, Orconectes hylas

    Science.gov (United States)

    Freeland-Riggert, Brandye T.

    2016-01-01

    Introductions of alien species into aquatic ecosystems have been well documented, including invasions of crayfish species; however, little is known about the effects of these introductions on macroinvertebrate communities. The woodland crayfish (Orconectes hylas (Faxon)) has been introduced into the St. Francis River watershed in southeast Missouri and has displaced populations of native crayfish. The effects of O. hylas on macroinvertebrate community composition were investigated in a fourth-order Ozark stream at two locations, one with the presence of O. hylas and one without. Significant differences between sites and across four sampling periods and two habitats were found in five categories of benthic macroinvertebrate metrics: species richness, percent/composition, dominance/diversity, functional feeding groups, and biotic indices. In most seasons and habitat combinations, the invaded site had significantly higher relative abundance of riffle beetles (Coleoptera: Elmidae), and significantly lower Missouri biotic index values, total taxa richness, and both richness and relative abundance of midges (Diptera: Chironomidae). Overall study results indicate that some macroinvertebrate community differences due to the O. hylas invasion were not consistent between seasons and habitats, suggesting that further research on spatial and temporal habitat use and feeding ecology of Ozark crayfish species is needed to improve our understanding of the effects of these invasions on aquatic communities. PMID:26986207

  17. Differences found in the macroinvertebrate community composition in the presence or absence of the invasive alien crayfish, Orconectes hylas

    Science.gov (United States)

    Freeland-Riggert, Brandye T.; Cairns, Stefan H.; Poulton, Barry C.; Riggert, Chris M.

    2016-01-01

    Introductions of alien species into aquatic ecosystems have been well documented, including invasions of crayfish species; however, little is known about the effects of these introductions on macroinvertebrate communities. The woodland crayfish (Orconectes hylas (Faxon)) has been introduced into the St. Francis River watershed in southeast Missouri and has displaced populations of native crayfish. The effects of O. hylas on macroinvertebrate community composition were investigated in a fourth-order Ozark stream at two locations, one with the presence of O. hylas and one without. Significant differences between sites and across four sampling periods and two habitats were found in five categories of benthic macroinvertebrate metrics: species richness, percent/composition, dominance/diversity, functional feeding groups, and biotic indices. In most seasons and habitat combinations, the invaded site had significantly higher relative abundance of riffle beetles (Coleoptera: Elmidae), and significantly lower Missouri biotic index values, total taxa richness, and both richness and relative abundance of midges (Diptera: Chironomidae). Overall study results indicate that some macroinvertebrate community differences due to the O. hylas invasion were not consistent between seasons and habitats, suggesting that further research on spatial and temporal habitat use and feeding ecology of Ozark crayfish species is needed to improve our understanding of the effects of these invasions on aquatic communities.

  18. Short-Term Effects of the 2008 High-Flow Experiment on Macroinvertebrates in Colorado River Below Glen Canyon Dam, Arizona

    Science.gov (United States)

    Rosi-Marshall, Emma J.; Kennedy, Theodore A.; Kincaid, Dustin W.; Cross, Wyatt F.; Kelly, Holly A.W.; Behn, Kathrine A.; White, Tyler; Hall, Robert O., Jr.; Baxter, Colden V.

    2010-01-01

    Glen Canyon Dam has dramatically altered the physical environment (especially discharge regime, water temperatures, and sediment inputs) of the Colorado River. High-flow experiments (HFE) that mimic one aspect of the natural hydrograph (floods) were implemented in 1996, 2004, and 2008. The primary goal of these experiments was to increase the size and total area of sandbar habitats that provide both camping sites for recreational users and create backwaters (areas of stagnant flow in the lee of return-current eddies) that may be important as rearing habitat for native fish. Experimental flows might also positively or negatively alter the rainbow trout (Oncorhynchus mykiss) sport fishery in the clear tailwater reach below Glen Canyon Dam, Ariz., and native fish populations in downstream reaches (for example, endangered humpback chub, Gila cypha) through changes in available food resources. We examined the short-term response of benthic macroinvertebrates to the March 2008 HFE at three sites [river mile 0 (RM 0, 15.7 miles downriver from the dam), RM 62, and RM 225] along the Colorado River downstream from Glen Canyon Dam by sampling immediately before and then 1, 7, 14, and 30 days after the HFE. We selected these sites because of their importance to management; RM 0 has a valuable trout fishery, and RM 62 is the location of the largest population of the endangered humpback chub in the Grand Canyon. In addition to the short-term collection of samples, as part of parallel investigations, we collected 3 years of monthly (quarterly for RM 62) benthic macroinvertebrate samples that included 15 months of post-HFE data for all three sites, but processing of the samples is only complete for one site (RM 0). At RM 0, the HFE caused an immediate 1.75 g AFDM/m2 (expressed as grams ash-free dry mass, or AFDM) reduction of macroinvertebrate biomass that was driven by significant reductions in the biomass of the two dominant taxa in this reach-Potamopyrgus antipodarum (New

  19. Efecto del reemplazo de la vegetación nativa de ribera sobre la comunidad de macroinvertebrados bentónicos en arroyos de climas templados, Chile central Replacement effect of riparian native vegetation on benthic macroinvertebrates community in temperate climate streams, Central Chile

    Directory of Open Access Journals (Sweden)

    Gabriela Mancilla

    2009-12-01

    Full Text Available El aporte de materia orgánica desde la vegetación ribereña es determinante en la estructura y complejidad de los sistemas fluviales; es identificado como el mayor aporte energético en ríos y una fuente importante de alimento para macroinvertebrados en arroyos de cabecera. No obstante, el paisaje ribereño ha sido altamente degradado por actividades humanas, lo que ha afectado la estructura y composición de las comunidades acuáticas. El presente estudio se desarrolló en Chile central (región del Biobío donde se concentra una intensa actividad forestal con especies exóticas. Se seleccionaron ríos de bajo orden (The organic matter from riparian vegetation is determined by the structure and complexity of streams. It presents a higher energetic input to streams as well as important source of food for macroinvertebrates in head streams. In spite of its importance, riparian landscape has been rapidly degraded by human activity, this affects structure and composition of the aquatic community. The present study was made in Central Chile (Biobio Region which has intensive forest activity with exotic species. Small streams were selected (< 3 order, because they are very particularly sensitive to changes in land use. The sites were grouped identified according to native forest land cover larger than 20% (group 1 and smaller than 20% (group 2. Significant differences (p< 0.05 in Plecoptera abundance (p < 0.05 were found between the two groups. Differences in trophic groups were significant for shredders and predators increased and gathering-collectors decreased their abundance, with native cover smaller than 20%. This showed the dependent on allochthonous material. The vegetation cover and community parameters correlations showed that Diversity (W increased with higher percentage of watershed covered by native vegetation and exotic species mix. Results suggest that a buffer conservation area of native riparian vegetation is necessary in streams

  20. Assessing the impact of chemical pollution on benthic invertebrates from three different European rivers using a weight-of-evidence approach

    Czech Academy of Sciences Publication Activity Database

    Wolfram, G.; Höss, S.; Orendt, C.; Schmitt, C.; Adámek, Zdeněk; Bandow, N.; Grossschartner, M.; Kukkonen, J. V. K.; Leloup, V.; López Doval, J. C.; Munoz, I.; Traunspurger, W.; Tuikka, A.; Van Liefferinge, C.; von der Ohe, P. C.; de Deckere, E.

    2012-01-01

    Roč. 438, X (2012), s. 498-509. ISSN 0048-9697 Institutional support: RVO:68081766 Keywords : Benthic macroinvertebrates * Nematodes * Chemical pollution * Bioassays * Sediment-quality triad (SQT) * Weight of evidence (WoE) Subject RIV: EH - Ecology, Behaviour Impact factor: 3.258, year: 2012

  1. Landscape composition as a determinant of diversity and functional feeding groups of aquatic macroinvertebrates in southern rivers of the Araucanía, Chile

    OpenAIRE

    Pablo Fierro; Carlos Bertrán; Maritza Mercado; Fernando Peña-Cortés; Jaime Tapia; Enrique Hauenstein; Luciano Caputo; Luis Vargas-Chacoff

    2015-01-01

    Changes in land use which directly or indirectly affect freshwater fauna constitute one of the principal anthropic factors which have caused world biological diversity to disappear rapidly during recent decades. This fauna includes aquatic benthic macroinvertebrates, organisms presenting temporal and spatial variation due to a variety of factors, one of which is the diverse food resources available in the rivers. To assess the effect of anthropic activities on this fauna, the distribution, ab...

  2. Invertebrate assemblage responses and the dual roles of resistance and resilience to drying in intermittent rivers

    OpenAIRE

    Leigh, C.; Bonada, N.; Boulton, A J; Hugueny, Bernard; Larned, S. T.; Vorste, R. V.; Datry, Thibault

    2016-01-01

    Intermittent rivers are naturally dynamic ecosystems in which flow cessation and riverbed drying cause temporal fluctuations in aquatic biodiversity. We analysed datasets from intermittent rivers in different climate zones across the world to examine responses of aquatic macroinvertebrate assemblages to drying, in relation to both taxonomic composition and traits of resistance and resilience. First, we compared the differences in taxonomic richness and turnover and in trait diversity, richnes...

  3. Aquatic macroinvertebrates of the Grand Calumet River

    Science.gov (United States)

    Last, Laurel L.; Whitman, Richard L.

    2000-01-01

    The Grand Calumet River is potential habitat for a rich community of aquatic macroinvertebrates. Historical surveys of these organisms have been limited to post-industrialization of the Calumet Region; but because river habitats and conditions prior to industrialization have been described, past macroinvertebrate composition can be inferred. In the past 20 years, several surveys have been conducted in the Grand Calumet that have focused on a limited area, but when these studies are amassed the information available covers much of the river. In this paper, the aquatic macroinvertebrate communities in the river are described, and options for restoration are discussed. Many of the macroinvertebrates present are indicators of high levels of pollution, but a few pollution-sensitive species have been found. There is evidence, however, that the sediment quality has improved since the 1960's, likely due to pollution controls that have been put into place. Restoration opportunities should consider the macroinvertebrate community and the potential to improve sediment habitat without damaging the community structure.

  4. Leaf litter decomposition and its relation with aquatic macroinvertebrates of the Gaira River (Santa Marta Colombia)

    International Nuclear Information System (INIS)

    The rate of decomposition of leaf litter of four native species and three exotic species were evaluated. They were selected due to the most frequently collected by the bank vegetation Gaira river, located on the sierra Nevada de Santa Marta. We took four sampling sections at different heights. Furthermore, it was evaluated the richness, abundance and trophic function of macroinvertebrates that colonized the artificial substrates containing leaf packs or meshes. The middle part had the greatest rate of decomposition of native and exotic species (kw = 15.9, n = 23, p = 0.001 and kw = 15.5, n = 36, p = 0.0014 respectively). The native species had the highest rates (kw = 4, n = 47, p = 0.04), with the species pithecellobium longifolium in the middle stretch, which had the greatest mass loss over time. Descriptively a relationship between decomposition rate and current velocity is presented. the macroinvertebrate assemblage was represented by 41 taxa, with an abundance of 1895 individuals which provided a biomass of 2.27 g. the functional structure of macroinvertebrates associated with leaf litter was represented in the upper, middle and low reaches by plecoptera (predators) of the genus anacroneuria with 10.14%, 68.43% and 7.60% respectively. The taxon tanypodinae (diptera) predators were dominant in the mouth with 0.51%. The result of this study can determinate whether the presence of macroinvertebrates associated with leaf litter, is not conditioned by the plant species (native or exotic), and not enter these differences that create an effect on the rate of decomposition.

  5. The Effects of Forest Disturbance on Macroinvertebrates in Western Oregon Headwater Streams - Patterns in Existing Databases

    Science.gov (United States)

    Herlihy, A. T.; Li, J.; Gerth, B.; Banks, J.

    2003-12-01

    As part of a research project investigating the effects of forest harvest practices on stream macroinvertebrates, we compiled existing data for Western Oregon headwater forest streams. The compiled database consists of 168 sites with watershed areas less than 10 square km that had measurements of stream macroinvertebrates, fish, physical habitat, water chemistry, and watershed land cover. The source of the data is from surveys conducted for EPA's EMAP program, the state of Oregon's Salmon Plan monitoring, and our own sampling efforts between 1994 and 2000. Almost all sites in the database were selected using the randomized EMAP survey design so they constitute a representative sample of all streams in this population. The streams in our dataset typically had mean wetted widths of 1-5 m, mean thalweg depths of 8-34 cm, and channel slopes of 1-15%. Watersheds for these sites were delineated and data on forest condition and logging history were clipped from available GIS layers. There were 189 macroinvertebrate taxa at the 168 sites with richness at individual sites ranging from 7 to 71 taxa. Ordination of the macroinvertebrate assemblages using NMS resulted in a 3 dimensional solution which accounted for 78% of the variation in the similarity among sites and demonstrated clear patterns in taxonomic composition with Baetis, Epeorus and Chironominae having the highest correlations with the ordination axes. Axes 1 and 2 each explained about 30% of the variation and were strongly correlated with substrate size, site slope and elevation. The third axis explained 17% of the variation and was correlated most strongly with watershed indices of forest logging history.

  6. Aquatic macroinvertebrate responses to native and non-native predators

    Directory of Open Access Journals (Sweden)

    Haddaway N. R.

    2014-01-01

    Full Text Available Non-native species can profoundly affect native ecosystems through trophic interactions with native species. Native prey may respond differently to non-native versus native predators since they lack prior experience. Here we investigate antipredator responses of two common freshwater macroinvertebrates, Gammarus pulex and Potamopyrgus jenkinsi, to olfactory cues from three predators; sympatric native fish (Gasterosteus aculeatus, sympatric native crayfish (Austropotamobius pallipes, and novel invasive crayfish (Pacifastacus leniusculus. G. pulex responded differently to fish and crayfish; showing enhanced locomotion in response to fish, but a preference for the dark over the light in response to the crayfish. P.jenkinsi showed increased vertical migration in response to all three predator cues relative to controls. These different responses to fish and crayfish are hypothesised to reflect the predators’ differing predation types; benthic for crayfish and pelagic for fish. However, we found no difference in response to native versus invasive crayfish, indicating that prey naiveté is unlikely to drive the impacts of invasive crayfish. The Predator Recognition Continuum Hypothesis proposes that benefits of generalisable predator recognition outweigh costs when predators are diverse. Generalised responses of prey as observed here will be adaptive in the presence of an invader, and may reduce novel predators’ potential impacts.

  7. Influence of bed heterogeneity and habitat type on macroinvertebrate uptake in peri-urban streams

    Institute of Scientific and Technical Information of China (English)

    REID,H.E.; BRIERLEY,G.J.; BOOTHROYD,I.K.G.

    2010-01-01

    The role of geomorphic structure, referred to as physical heterogeneity, and its influence upon the colonization of habitat by macroinvertebrates was analysed in the peri-urban, Twin Streams Catchment, in West Auckland, New Zealand. Using a cross-scalar approach, 4 riffle-run assemblages were analysed in each of 2 River Styles (a confined, low sinuosity, gravel bed river and a partly confined, low sinuosity, bedrock, cobble, and gravel bed river). Each of these 8 locations comprised 2 distinct sampling areas; the upstream zone had a more heterogeneous river bed with a high diversity of physical features and flow, whilst the downstream area had a more homogeneous structure. Microhabitat features sampled at each site included streambed material, bank margins, fine grained organic debris, wood, and boulders. Habitat mosaics and their associated macroinvertebrate relationships followed a semi-predictable but interrupted pattern, supporting the view that river systems are a patchy discontinuum. Homogeneous zones were more frequently characterised by higher proportions of Trichoptera than heterogeneous zones, whilst heterogeneous zones were frequently characterised by Plecoptera and Ephemeroptera. Diversity was maximised when the species pools from heterogeneous and homogeneous sites were combined for any given site. Functional habitats influenced macroinvertebrate assemblages in non-linear and complex ways. Wood and organic debris habitats were associated with high diversity, abundance, and sensitive species whereas streambed habitat was usually associated with low diversity. A diverse range of physical zones that approximates the 'natural range of behaviour' for the given type of stream was considered to provide a more effective platform for rehabilitation planning than emphasising heterogeneity of physical structure in its own right.

  8. The role of benthic foraminifera in the benthic nitrogen cycle of the Peruvian oxygen minimum zone

    Directory of Open Access Journals (Sweden)

    N. Glock

    2012-12-01

    Full Text Available The discovery that foraminifera are able to use nitrate instead of oxygen as energy source for their metabolism has challenged our understanding of nitrogen cycling in the ocean. It was evident before that only prokaryotes and fungi are able to denitrify. Rate estimates of foraminiferal denitrification were very sparse on a regional scale. Here, we present estimates of benthic foraminiferal denitrification rates from six stations at intermediate water depths in and below the Peruvian oxygen minimum zone (OMZ. Foraminiferal denitrification rates were calculated from abundance and assemblage composition of the total living fauna in both, surface and subsurface sediments, as well as from individual species specific denitrification rates. A comparison with total benthic denitrification rates as inferred by biogeochemical models revealed that benthic foraminifera account for the total denitrification on the shelf between 80 and 250 m water depth. They are still important denitrifiers in the centre of the OMZ around 320 m (29–56% of the benthic denitrification but play only a minor role at the lower OMZ boundary and below the OMZ between 465 and 700 m (3–7% of total benthic denitrification. Furthermore, foraminiferal denitrification was compared to the total benthic nitrate loss measured during benthic chamber experiments. Foraminiferal denitrification contributes 1 to 50% to the total nitrate loss across a depth transect from 80 to 700 m, respectively. Flux rate estimates ranged from 0.01 to 1.3 mmol m−2 d−1. Furthermore we show that the amount of nitrate stored in living benthic foraminifera (3 to 705 µmol L−1 can be higher by three orders of magnitude as compared to the ambient pore waters in near surface sediments sustaining an important nitrate reservoir in Peruvian OMZ sediments. The substantial contribution of foraminiferal nitrate respiration to total benthic nitrate loss at the Peruvian margin

  9. Effects of sea bass and sea bream farming (Western Mediterranean Sea) on peracarid crustacean assemblages

    OpenAIRE

    Fernandez-Gonzalez, Victoria; Sanchez-Jerez, Pablo

    2011-01-01

    Benthic soft–bottom assemblages are good indicators of environmental disturbance, such as coastal aquaculture, considering their rapid response in terms of diversity and abundance. The aim of this study was to evaluate the response of peracarid assemblages to the release of waste from coastal farming as these organisms play an important ecological role. Abundance and species richness did not show significant differences between farm and control localities but did show a high spatial variabili...

  10. Macroinvertebrates communities associated with the decomposition of Phragmites australis and Fucus vesiculosus in transitional systems

    Science.gov (United States)

    Lopes, Marta Lobão; Martins, Patrícia; Rodrigues, Ana Maria; Quintino, Victor

    2013-10-01

    The decomposition rates of a macrophyte (Phragmites australis) and an alga (Fucus vesiculosus) and the associated macrofauna communities were studied along a full salinity gradient, using the leaf-bag technique and four sampling times (days 3, 7, 15 and 30). A control was set up using an artificial substrate. A subsequent study conducted in the mesohaline part of the salinity gradient also included empty bags as procedure control. The decay rates of the alga and the macrophyte were significantly different, the alga decaying faster, and presented an opposite trend along the salinity gradient, with the faster decay rate for reed in the less saline areas and for the alga in the euhaline part of the gradient. The fauna associated with the decaying and the artificial substrate showed equally well the benthic succession from the marine to the freshwater areas, in all sampling times. Arthropods were dominant in all substrates along the estuarine gradient and replaced by annelids in freshwater. No significant differences were found between the benthic communities associated with P. australis and F. vesiculosus, despite the strong differences in the decay rates, suggesting that these do not seem to be primarily related to the benthic colonizers. Although the organic substrates sustained a more abundant fauna, the benthic communities did not show significant differences between the organic and the artificial substrates, especially at the level of the species composition, suggesting that the macroinvertebrates may colonize both substrates to feed on the biofilm and/or to seek shelter. The strongly impoverished benthic community sampled by the empty bags reinforced this idea.

  11. Messinian paleoenvironmental evolution in the lower Guadalquivir Basin (SW Spain) based on benthic foraminifera.

    OpenAIRE

    Pérez-Asensio, J.N.; Aguirre, J.; Schmiedl, G.; Civis Llovera, J.

    2012-01-01

    Benthic foraminiferal assemblages of a drill core from the lower Guadalquivir Basin (northern Gulf of Cádiz, SW Spain) have been analyzed in order to reconstruct the paleoenvironmental evolution in the vicinity of the Betic seaways during the Messinian. The core consists of marine sediments ranging from the latest Tortonian to the early Pliocene. Changes in the abundance of certain marker species, planktonic/benthic ratio (P/B ratio), paleodepth estimated with a transfer function, content of ...

  12. The role of bio-hydrodynamic interactions in determining the functioning of shallow, benthic ecosystems

    OpenAIRE

    Morris, Edward P; Peralta, Gloria; Brun, Fernando G.; Bouma, Tjeerd J.; Hendriks, Iris E; Benavente, Javier; Lara, Miguel; González-Ortiz, Vanesa; Van Engeland, Tom; Van Duren, Luca A.; Perez-Llorens, J. Lucas

    2011-01-01

    Epi-benthic organisms play a strong role in controlling pelagic-benthic mass transfer rates by directly modifying concentration gradients (i.e., production, or removal of material) and by indirectly modifying near-bed hydrodynamics. Focusing on these bio-hydrodynamic interactions, we will demonstrate how the physical structure of different assemblages, via their interaction with currents and waves, results in spatio-temporal variation in transfer rates at a range of scales. Examples will be u...

  13. Altitudinal distribution limits of aquatic macroinvertebrates

    DEFF Research Database (Denmark)

    Madsen, Philip B.; Morabowen, Andrés; Andino, Patricio;

    2015-01-01

    1. Temperature and oxygen are recognised as the main drivers of altitudinal limits of species distributions. However, the two factors are linked, and both decrease with altitude, why their effects are difficult to disentangle. 2. This was experimentally addressed using aquatic macroinvertebrates...

  14. The long-term effects of invasive signal crayfish (Pacifastacus leniusculus) on instream macroinvertebrate communities.

    Science.gov (United States)

    Mathers, Kate L; Chadd, Richard P; Dunbar, Michael J; Extence, Chris A; Reeds, Jake; Rice, Stephen P; Wood, Paul J

    2016-06-15

    Non-native species represent a significant threat to indigenous biodiversity and ecosystem functioning worldwide. It is widely acknowledged that invasive crayfish species may be instrumental in modifying benthic invertebrate community structure, but there is limited knowledge regarding the temporal and spatial extent of these effects within lotic ecosystems. This study investigates the long term changes to benthic macroinvertebrate community composition following the invasion of signal crayfish, Pacifastacus leniusculus, into English rivers. Data from long-term monitoring sites on 7 rivers invaded by crayfish and 7 rivers where signal crayfish were absent throughout the record (control sites) were used to examine how invertebrate community composition and populations of individual taxa changed as a result of invasion. Following the detection of non-native crayfish, significant shifts in invertebrate community composition were observed at invaded sites compared to control sites. This pattern was strongest during autumn months but was also evident during spring surveys. The observed shifts in community composition following invasion were associated with reductions in the occurrence of ubiquitous Hirudinea species (Glossiphonia complanata and Erpobdella octoculata), Gastropoda (Radix spp.), Ephemeroptera (Caenis spp.), and Trichoptera (Hydropsyche spp.); although variations in specific taxa affected were evident between regions and seasons. Changes in community structure were persistent over time with no evidence of recovery, suggesting that crayfish invasions represent significant perturbations leading to permanent changes in benthic communities. The results provide fundamental knowledge regarding non-native crayfish invasions of lotic ecosystems required for the development of future management strategies. PMID:26974569

  15. Benthic foraminiferal distribution in surface sediments along continental slope of the southern Okinawa Trough:dependance on water masses and food supply

    Institute of Scientific and Technical Information of China (English)

    向荣; 李铁刚; 杨作升; 阎军; 曹奇原

    2003-01-01

    Benthic foraminiferal analysis of 29 samples in surface sediments from the southern Oki-nawa Trough is carried out. The results indicate that benthic foraminiferal abundance decreases rapidlywith increasing water depth. Percentage frequencies of agglutinated foraminifera further confirm themodem shallow carbonate lysocline in the southern Okinawa Trough. From continental shelf edge to thebottom of Okinawa Trough, benthic foraminiferal fauna in the surface sediments can be divided into 5assemblages: (1) Continental shelf break assemblage, dominated by Cibicides pseudoungerianus, corre-sponds to subsurface water mass of the Kuroshio Current; (2) upper continental slope assemblage, domi-nated by Cassidulina carinata, Globocassidulina subglobosa, corresponds to intermediate water mass of the Kuroshio Current; (3) intermediate continental slope assemblage, dominated by Uvigerina hispi-da, corresponds to the Okinawa Trough deep water mass above the carbonate lysocline; (4) lower con-tinental slope- trough bottom assemblage, dominated by Pullenia bulloides, Epistominella exigua andCibicidoides hyalinus, corresponds to deep water mass of the Okinawa Trough; and (5) trough bottomagglutinated assemblage, dominated by Rhabdammina spp., Bathysiphon flavidus, corresponds tostrongly dissolved environment of the trough bottom. The benthic foraminiferal fauna in the southemOkinawa Trough are controlled jointly by water masses and food supply. Water temperature, oxygenconcentration and carbonate dissolution of the water masses are important controlling factors especiallyfor the continental shelf break and trough bottom assemblages. The food supply also plays an importantrole in these benthic foraminiferal assemblages along the westem slope of the Okinawa Trough. Both theabundance and the 5 assemblages of benthic foraminifera correspond well to the organic matter supplyalong the continental slope and a lateral transport of TSM (total suspended matter) and POC (particulateorganic

  16. Benthic macrofauna and the limnological parameters of a first-order stream in Atlantic Forest of Brazilian Northeast

    OpenAIRE

    Janaina Câmara Siqueira da Cunha; Renato Galindo de Barros Filho; Rafael Pereira da Silva; Iris Gabrielly Arruda dos Santos; Gilberto Gonçalves Rodrigues

    2014-01-01

    AIM: The present study aimed to elucidate if the water physical and chemical parameters from a first order stream of Biological Reserve of Saltinho from south Pernambuco induces in the distribution and abundance of benthic macroinvertebrates. METHODS: Both limnological parameters (pH-value, electrical conductivity, water temperature, turbidity, salinity and dissolved oxygen) and structural variables of aquatic habitat (substrate, food availability and flow velocity) influence the macroinverte...

  17. Landscape composition as a determinant of diversity and functional feeding groups of aquatic macroinvertebrates in southern rivers of the Araucanía, Chile

    Directory of Open Access Journals (Sweden)

    Pablo Fierro

    2015-03-01

    Full Text Available Changes in land use which directly or indirectly affect freshwater fauna constitute one of the principal anthropic factors which have caused world biological diversity to disappear rapidly during recent decades. This fauna includes aquatic benthic macroinvertebrates, organisms presenting temporal and spatial variation due to a variety of factors, one of which is the diverse food resources available in the rivers. To assess the effect of anthropic activities on this fauna, the distribution, abundance and characterisation of the functional feeding groups of aquatic macroinvertebrates were analysed, together with the physical and chemical variables in the environments of four coastal river basins of southern south-central Chile. A total of 104 taxa of macroinvertebrates were recorded, the principal component of the community being the Diptera (26 taxa. The abundance and richness of taxa were greater in summer and lower in winter. The most abundant species belong to the order Ephemeroptera and Plecoptera. Macroinvertebrates were affected by different land use: stations with less anthropic activity and greater altitude had higher macroinvertebrates abundance, while the lowest abundance was found at the lowest stations. The functional feeding groups which were most abundant spatially and temporally were the collector-gatherers and the shredders. The physical and chemical water quality variables proved to be of exceptional quality in all the stations. These results suggest that policies governing changes in land use in central and southern Chile should take into account the dramatic alterations that these changes impose on the macroinvertebrates community. Policies for biodiversity conservation should therefore focus on these small but important organisms in the north Patagonian region of South America, which is a hotspot of world diversity.

  18. The Gelså River Restoration Revisited:Community persistence of the macroinvertebrate community over an 11-year period

    OpenAIRE

    Friberg, Nikolai; Baattrup-Pedersen, Annette; Kristensen, Esben; Kronvang, Brian; Larsen, Søren Erik; Pedersen, Morten Lauge; Skriver, Jens; Thodsen, Hans; Wiberg-Larsen, Peter

    2014-01-01

    The study was undertaken on the River Gelså, Denmark, where a 1.8 km meandering course was estab-lished in 1989 to replace a channelized river reach. This restoration project was the first of its kind inDenmark and has the longest time-series of post-intervention data of any restoration project conductedworld-wide. Additionally, a 0.5 km upstream (control) reach that remained channelized has been sampledsince 1989. In this paper, we examined macroinvertebrate assemblages in distinct habitats ...

  19. Biodilution of heavy metals in a stream macroinvertebrate food web: Evidence from stable isotope analysis

    International Nuclear Information System (INIS)

    Analysis of carbon (δ13C) and nitrogen (δ15N) stable isotopes provides an increasingly important means of understanding the complex trophic structure of macroinvertebrate communities in streams. We coupled a stable isotope approach with a contaminant analysis of six metals (Pb, Ag, Zn, Hg, Cu, As) to trace the accumulation and dilution of metals from an abandoned mine across trophic levels of the benthic community in Ginzan Creek, Japan. The δ15N signature increased with trophic level, with mean increases of 4.70 per mille from producers to primary consumers and 3.06 per mille from primary to secondary consumers. Tissue Pb and Ag concentrations were negatively correlated with δ15N, indicating biodilution of both metals through the food web. Although macroinvertebrate taxon body mass was negatively correlated with tissue metal concentration at several sites, it did not increase with trophic level (as δ15N) in any of the sites, suggesting that changes in body mass were not the cause of biodilution. Our findings suggest invertebrates at higher trophic levels may exhibit increasingly efficient excretion of metals. Autotrophic epilithon (mean δ13C = - 21.3 per mille ) had a much higher concentration of mined metals than did riparian vegetation (mean δ13C = -29.3 per mille ); nonetheless, a carbon-mixing model indicated that taxa feeding on autochthonous carbon sources did not accumulate more metal than allochthonous feeders. It is likely that the notably high metal concentration of allochthonous FPOM plays an important role in the trophic transfer of metals. Our data suggest the strong potential for stable isotope analysis to enhance our understanding of metal transfer through stream macroinvertebrate food webs

  20. Relationship between sugar cane cultivation and stream macroinvertebrate communities

    OpenAIRE

    Juliano José Corbi; Susana Trivinho-Strixino

    2008-01-01

    The aim of this work was to study the influence of the sugar cane cultivation on the macroinvertebrate communities of 11 streams under different land uses. Analysis of the sediment (organic matter contents and metals) and water complemented the study. Ninety six macroinvertebrates taxa were identified, of which 54 were Chironomidae and 42 of other aquatic macroinvertebrates. The streams located in the areas of sugar cane culture and pasture presented low taxa and a great participation of Chir...

  1. Taxonomic spectrum of macroinvertebrate communities in Săsar River (NW Romania

    Directory of Open Access Journals (Sweden)

    Oana-Elena MARE ROŞCA

    2010-05-01

    Full Text Available The following article analyses the taxonomic composition of benthic macroinvertebrates in Săsar river, which flows in the North West of Romania in a highly industrialized area. According to prior studies, increased biological unbalances have been observed due to mining activities, meaning that Săsar river, out of its 31 kilometers from the spring to the flow, has 17 kilometers which are completely downgraded. According to the systematic research done between 2003-2006, 41 taxa were identified. After working with the physical-chemical monitoring data, it was noticed that the low diversity of zoobenthic communities was due to the toxic pollutants from the mining and metallurgic industries.

  2. Acid mine drainage and stream recovery: Effects of restoration on water quality, macroinvertebrates, and fish

    Directory of Open Access Journals (Sweden)

    Williams K.M.

    2015-01-01

    Full Text Available Acid mine drainage (AMD is a prominent threat to water quality in many of the world’s mining districts as it can severely degrade both the biological community and physical habitat of receiving streams. There are relatively few long-term studies investigating the ability of stream ecosystems to recover from AMD. Here we assess watershed scale recovery of a cold-water stream from pollution by AMD using a 1967 survey of the biological and chemical properties of the stream as a pre-restoration benchmark. We sampled water chemistry, benthic macroinvertebrates, and fish throughout the watershed during the spring and summer of 2011. Water chemistry results indicated that pH and total alkalinity increased post-restoration, while acidity, sulfate, and iron concentrations decreased. Watershed-level taxa richness, local taxa richness, biomass, diversity, and density of macroinvertebrates were significantly higher post-restoration; however, %EPT was not significantly different. Fish species richness, density, and brook trout density were all significantly higher post-restoration. These results provide clear evidence that both abiotic and biotic components of streams can recover from AMD pollution.

  3. Application of “taxocene surrogation” and “taxonomic sufficiency” concepts to fish farming environmental monitoring. Comparison of BOPA index versus polychaete assemblage structure

    OpenAIRE

    Aguado Giménez, Felipe; Gairin Deulofeu, Joan Ignasi; Martinez-Garcia, Elena; Fernandez-Gonzalez, Victoria; Ballester-Moltó, Mateo; Cerezo-Valverde, Jesús; Sanchez-Jerez, Pablo

    2015-01-01

    “Taxocene surrogation” and “taxonomic sufficiency” concepts were applied to the monitoring of soft bottoms macrobenthic assemblages influenced by fish farming following two approaches. Polychaete assemblage evaluation through multivariate analysis and the benthic index BOPA were compared. Six fish farms along the Spanish Mediterranean coast were monitored. Polychaete assemblage provided a suitable picture of the impact gradient, being correlated with total free sulphides. BOPA did not support...

  4. Using a Geospatial Model to Relate Fluvial Geomorphology to Macroinvertebrate Habitat in a Prairie River—Part 1: Genus-Level Relationships with Geomorphic Typologies

    Directory of Open Access Journals (Sweden)

    Anna G. N. Meissner

    2016-01-01

    Full Text Available Modern river ecosystems undergo constant stress from disturbances such as bank stabilization, channelization, dams, and municipal, agricultural, and industrial water use. As these anthropogenic water requirements persist, more efficient methods of characterizing river reaches are essential. Benthic macroinvertebrates are helpful when evaluating fluvial health, because they are often the first group to react to contaminants that can then be transferred through them to other trophic levels. Hence, the purpose of this research is to use a geospatial model to differentiate instream macroinvertebrate habitats, and determine if the model is a viable method for stream evaluation. Through the use of ArcGIS and digital elevation models, the fluvial geomorphology of the Qu’Appelle River in Saskatchewan (SK was assessed. Four geomorphological characteristics of the river were isolated (sinuosity, slope, fractal dimension, and stream width and clustered through Principle Component Analysis (PCA, yielding sets of river reaches with similar geomorphological characteristics, called typologies. These typologies were mapped to form a geospatial model of the river. Macroinvertebrate data were aligned to the locations of the typologies, revealing several relationships with the fluvial geomorphology. A Kruskal-Wallis analysis and post hoc pairwise multiple comparisons were completed with the macroinvertebrate data to pinpoint significant genera, as related to the geospatial model.

  5. Affects and assemblages

    DEFF Research Database (Denmark)

    Samson, Kristine

    happens to aesthetics and how does it change the existing social and geographical understanding of urban space? The paper sets out to reintroduce aesthetical aspects of affects and assemblages in relation to urban space and urban planning. It presupposes urban space as a continuous state of becoming where...... ‘throwntogetherness’ (Massey 2005) or assemblage (Farias & Bender 2010) of perspectives bridging for instance the social and cultural experienced space investigated by the geographer and urban sociologist with the material and formal aesthetics of the architect and urban planner....... cultural geopgraphy. On this backdrop the paper states that affects and assemblages could serve as key notions for the reassembling the aesthetics of urban space. Thus, the paper suggest a less formal understanding of urban space and aesthetics, proposing an understanding of aesthetics as a...

  6. Effects of sea bass and sea bream farming (Western Mediterranean Sea on peracarid crustacean assemblages

    Directory of Open Access Journals (Sweden)

    Fernandez–Gonzalez, V.

    2011-06-01

    Full Text Available Benthic soft-bottom assemblages are good indicators of environmental disturbance, such as coastal aquaculture, considering their rapid response in terms of diversity and abundance. The aim of this study was to evaluate the response of peracarid assemblages to the release of waste from coastal farming as these organisms play an important ecological role. Abundance and species richness did not show significant differences between farm and control localities but did show a high spatial variability at the two studied scales. Non-metric multi- dimensional scaling (MDS analysis showed a separation between farms and controls, indicating that peracarid assemblages are modified as a result of aquaculture activities, and some species such as Ampelisca spp. showed statistical differences. Peracarids, at both species and community level, may therefore be applied as helpful indicators to assess benthic effects of coastal farming.

  7. Invasive alien species water hyacinth Eichhornia crassipes as abode for macroinvertebrates in hypertrophic Ramsar Site, Lake Xochimilco, Mexico.

    Science.gov (United States)

    Rocha-Ramirez, A; Robles-Valderrama, E; Ramirez-Flores, E

    2014-11-01

    This paper presents information on the density, diversity and functional feeding groups of macroinvertebrate assemblages associated with water hyacinth in Antiguo Canal Cuemanco, part of Lake Xochimilco in Mexico City. Rare (low frequency and density) and dominant (high frequency and density) taxa prevailed in the assemblages, with the most predominant being Hyalella azteca, Chironomus plumosus and Ischnura denticollis. Nonmetric Multidimensional Scaling confirmed two climatic seasons: warm-rainy and cold-dry; the former with the highest diversity and density of taxa. Canonical Correspondence Analysis showed that conductivity, nitrates and turbidity explained the density variations of taxa. Antiguo Canal Cuemanco waters are spatially homogeneous with the characteristics of hypertrophic shallow lakes, inhabited by scrapers and gathering-collectors. The species found were tolerant to organic pollution. PMID:25522508

  8. Recent benthic foraminifera from the Caribbean continental slope and shelf off west of Colombia

    Science.gov (United States)

    Fiorini, Flavia

    2015-07-01

    A quantitative benthic foraminiferal analysis was conducted on 30 sea-floor sediment samples distributed along the continental slope and shelf in Fuerte Area (Colombian Caribbean), between 39 and 2469 m water depth. The aims of the research were to provide data on the distribution of southwestern Caribbean Recent benthic foraminifera, to estimate changes in the foraminiferal distribution related to the bathymetry and the characteristics of the substrate, to define a data-bank on distribution of recent tropical benthic foraminifera from the southwestern Caribbean, to provide reference on foraminiferal distribution that can be used in bathymetric reconstructions of ancient environments. Three different assemblages corresponding to three different environments were identified by cluster analysis. Assemblage A, characterized by variable percentages of porcellaneous, hyaline and agglutinated benthic foraminifera indicative of shelf environments. Assemblage B, dominated by calcareous hyaline foraminifera mainly composed of infaunal foraminifera corresponding to upper bathyal, marine conditions. Assemblage C, composed by agglutinated and calcareous hyaline foraminifera characteristic of normal deep-water marine environments.

  9. Response of deep-sea benthic foraminifera to Miocene paleoclimatic events, DSDP site 289

    International Nuclear Information System (INIS)

    Changes in the Miocene deep-sea benthic foraminifera at DSDP Site 289 closely correlate to the climatically induced variations in deep and bottom waters in the Pacific Ocean. In early Miocene time, oxygen and carbon isotopes indicate that bottom waters were relatively warm and poorly oxygenated. Benthic foraminiferal assemblages are characterized by various species inherited from the Oligocene. Expansion of the Antarctic icecap in the early middle Miocene, 14-16 m.y. ago, increased oxygen isotope values, produced cold, more oxygenated bottom waters and lead to a turnover in the benthic foraminifera. An Oligocene-early Miocene assemblage was replaced by a cibicidoid-dominated assemblage. Some species became extinct and benthic faunas became more bathymetrically restricted with the increased stratification of deep waters in the ocean. In mid-Miocene time, Epistominella exigua and E. umbonifera, indicative of young, oxygenated bottom waters, are relatively common at DSDP Site 289. Further glacial expansion 5-9 m.y. ago lowered sealevel, increased oceanic upwelling and associated biological productivity and intensified the oxygen minima. Abundant hispid and costate uvigerines become a dominant faunal element at shallow depths above 2500 m as E. umbonifera becomes common to abundant below 2500 m. By late Miocene time, benthic faunas similar in species composition and proportion to modern faunas on the Ontong-Java plateau, had become established. (Auth.)

  10. Maximum ecological potential of tropical reservoirs and benthic invertebrate communities.

    Science.gov (United States)

    Molozzi, Joseline; Feio, Maria João; Salas, Fuensanta; Marques, João Carlos; Callisto, Marcos

    2013-08-01

    The Reference Condition Approach (RCA) is now widely adopted as a basis for the evaluation of the ecological quality of water bodies. In accordance with the RCA, the integrity of communities found in a given location should be analyzed according to their deviation from the communities that would be expected in the absence of anthropogenic disturbances. The RCA was used here with the aim of defining the Maximum Ecological Potential (MEP) of tropical reservoirs located in the hydrographical basin of the Paraopeba River in the state of Minas Gerais, Brazil. Among the reservoirs, Serra Azul is used as a water supply and is located in a core area of environmental protection where tourism is not allowed and the native vegetation is conserved. The benthic macroinvertebrate communities at 90 sites located in three reservoirs were analyzed and sampled every 3 months over 2 years. The temporal patterns of the communities in the three reservoirs were analyzed (2nd-STAGE MDS and ANOSIM) and were not significantly related to seasonal fluctuations in temperature and precipitation. Twenty-eight sites belonging to the Serra Azul reservoir were selected to define the MEP of these reservoirs because these sites had the lowest human disturbance levels. The macroinvertebrate taxa present in the selected MEP sites are similar to those of natural lakes and different from the communities of disturbed sites. The biological classification of these sites revealed two groups with distinct macroinvertebrate communities. This distinction was related to climatic variables, bottom substrate type, the presence of gravel/boulders, coarse sand, silt, clay or muck, depth, and the shoreline substrate zone. These two subsets of biological communities and respective environmental conditions can serve as a basis for the future implementation of ecological quality monitoring programs for tropical reservoirs in the study area. This approach can also, however, be implemented in other geographic areas

  11. Macroinvertebrate community assembly in pools created during peatland restoration.

    Science.gov (United States)

    Brown, Lee E; Ramchunder, Sorain J; Beadle, Jeannie M; Holden, Joseph

    2016-11-01

    Many degraded ecosystems are subject to restoration attempts, providing new opportunities to unravel the processes of ecological community assembly. Restoration of previously drained northern peatlands, primarily to promote peat and carbon accumulation, has created hundreds of thousands of new open water pools. We assessed the potential benefits of this wetland restoration for aquatic biodiversity, and how communities reassemble, by comparing pool ecosystems in regions of the UK Pennines on intact (never drained) versus restored (blocked drainage-ditches) peatland. We also evaluated the conceptual idea that comparing reference ecosystems in terms of their compositional similarity to null assemblages (and thus the relative importance of stochastic versus deterministic assembly) can guide evaluations of restoration success better than analyses of community composition or diversity. Community composition data highlighted some differences in the macroinvertebrate composition of restored pools compared to undisturbed peatland pools, which could be used to suggest that alternative end-points to restoration were influenced by stochastic processes. However, widely used diversity metrics indicated no differences between undisturbed and restored pools. Novel evaluations of restoration using null models confirmed the similarity of deterministic assembly processes from the national species pool across all pools. Stochastic elements were important drivers of between-pool differences at the regional-scale but the scale of these effects was also similar across most of the pools studied. The amalgamation of assembly theory into ecosystem restoration monitoring allows us to conclude with more certainty that restoration has been successful from an ecological perspective in these systems. Evaluation of these UK findings compared to those from peatlands across Europe and North America further suggests that restoring peatland pools delivers significant benefits for aquatic fauna by

  12. Matching biological traits to environmental conditions in marine benthic ecosystems

    Science.gov (United States)

    Bremner, J.; Rogers, S. I.; Frid, C. L. J.

    2006-05-01

    The effects of variability in environmental conditions on species composition in benthic ecosystems are well established, but relatively little is known about how environmental variability relates to ecosystem functioning. Benthic invertebrate assemblages are heavily involved in the maintenance of ecological processes and investigation of the biological characteristics (traits) expressed in these assemblages can provide information about some aspects of functioning. The aim of this study was to establish and explore relationships between environmental variability and biological traits expressed in megafauna assemblages in two UK regions. Patterns of trait composition were matched to environmental conditions and subsets of variables best describing these patterns determined. The nature of the relationships were subsequently examined at two separate scales, both between and within the regions studied. Over the whole area, some traits related to size, longevity, reproduction, mobility, flexibility, feeding method, sociability and living habit were negatively correlated with salinity, sea surface temperature, annual temperature range and the level of fishing effort, and positively associated with fish taxon richness and shell content of the substratum. Between the two regions, reductions in temperature range and shell content were associated with infrequent relative occurrences of short-lived, moderately mobile, flexible, solitary, opportunistic, permanent-burrow dwelling fauna and those exhibiting reproductive strategies based on benthic development. Relationships between some traits and environmental conditions diverged within the two regions, with increases in fishing effort and shell content of the substratum being associated with low frequencies of occurrence of moderately mobile and moderately to highly flexible fauna within one region, but high frequencies in the other. These changes in trait composition have implications for ecosystem processes, with, for

  13. Assessment of Ecological Quality of the Tajan River in Iran Using a Multimetric Macroinvertebrate Index and Species Traits

    Science.gov (United States)

    Aazami, Jaber; Esmaili Sari, Abbas; Abdoli, Asghar; Sohrabi, Hormoz; Van den Brink, Paul J.

    2015-07-01

    The objectives of this study were to assess the biological water of the Iranian Tajan River using different metrics, i.e., a Multimetric Macroinvertebrate Index (MMI) and a traits-based method. Twenty-eight physico-chemical parameters, 10 habitat factors, and abundance of macroinvertebrates were obtained for 17 sites. The Shahid-Rajaie dam divides the Tajan River into an up- and downstream part, with different land uses. Eighteen metrics were used to represent four components of ecosystem quality, including tolerance (Hilsenhoff, SIGNAL), diversity (Margalef, Shannon-Wiener, Simpson, and Evenness), abundance (total number of taxa, individuals, Ephemeroptera, Plecoptera, Trichoptera, EPT, and Insects), and composition of assemblages (% Ephemeroptera, % Plecoptera, % Trichoptera, and % EPT Taxa). The integrated MMI was calculated by averaging the obtained scores of all indices. In the next step, we gathered information on 22 biological traits of macroinvertebrates to evaluate whether (group of) traits could be identified that are indicative for specific or general stress. Result showed a decrease in MMI from upstream (very good water quality) to downstream (bad) due to human activities. Industrial activities like pulping and papermaking operations or sand mining in the downstream part had more effects than agriculture and fish ponds in the upstream part. A redundancy analysis biplot showed the variation between the modalities of trait of macroinvertebrates and their correlation with physico-chemical parameters in Tajan River. The findings show that traits can be indicative for different kind of stress but that more effort has to be put in gathering data sets to disentangle the effect of habitat quality, pollution, and the physico-chemical properties of high- versus lowland rivers.

  14. Macroinvertebrates associated with bryophyta in a first-order Atlantic Forest stream

    Directory of Open Access Journals (Sweden)

    Beatriz F. J. V. Rosa

    2011-06-01

    Full Text Available This study describes the composition and structure of the benthic community associated with bryophytes in a first-order stream, located in a biological reserve of the Atlantic Forest, during two seasons. During three months of the dry season of 2007 and three months of the rainy season of 2008, samples of bryophytes attached to stones were collected randomly, along a 100 m stream reach. The structure of the community was analyzed through the mean density of individuals, Shannon's diversity index, Pielou's evenness, family richness, dominance index, and the percentage of Ephemeroptera, Plecoptera and Trichoptera (% EPT. Chironomidae larvae were dominant in the two periods of study, followed by Ceratopogonidae in the rainy season, and Naididae in the dry season. The orders EPT contributed 14 families. The results showed that bryophytes constitute suitable habitat which is able to shelter an abundant and diversified benthic fauna in a small extension of the stream. This habitat provides refuge during spates, and thus minimizes downstream transport of the macroinvertebrate fauna.

  15. Fashion, Mediations & Method Assemblages

    DEFF Research Database (Denmark)

    Sommerlund, Julie; Jespersen, Astrid Pernille

    , it is an important ambition of this paper to go into a methodological discussion of how "that which effectively happens" can be approached. To this end, the paper will combine Hennion's term of the "mediator" with John Laws methodological term of "method assemblages". Method assemblages is a suggested as a way...... relations between individuals and social contexts, aesthetics and production, distribution and consumption, as well as relations between fluidity and stability. By addressing the field of fashion, the paper proposes to shed light on an empirical setting which has so far been studied either as a purely...... - Domestication of the Scallops and Fishermen of St. Brieuc Bay. Power, Action, and Belief - A New Sociology of Knowledge. J. Law. London, Routledge and Keagan Paul: 196-233. Hennion, A. (1997). "Baroque and rock: Music, mediators and musical taste." Poetics 24: 414 - 435. Latour, B. (1993). We Have Never Been...

  16. The influence of partial timber harvest in riparian management zones on macroinvertebrate and fish communities on first- and second-order streams in northern Minnesota

    Science.gov (United States)

    Chizinski, Christopher J.; Vondracek, Bruce C.; Blinn, Charles R.; Newman, Raymond M.; Atuke, Dickson M.; Fredricks, Keith; Hemstad, Nathaniel A.; Merten, Eric; Schlesser, Nicholas

    2010-01-01

    Relatively few evaluations of aquatic macroinvertebrate and fish communities have been published in peer-reviewed literature detailing the effect of varying residual basal area (RBA) after timber harvesting in riparian buffers. Our analysis investigated the effects of partial harvesting within riparian buffers on aquatic macroinvertebrate and fish communities in small streams from two experiments in northern Minnesota northern hardwood-aspen forests. Each experiment evaluated partial harvesting within riparian buffers. In both experiments, benthic macroinvertebrates and fish were collected 1 year prior to harvest and in each of 3 years after harvest. We observed interannual variation for the macroinvertebrate abundance, diversity and taxon richness in the single-basin study and abundance and diversity in the multiple-basin study, but few effects related to harvest treatments in either study. However, interannual variation was not evident in the fish communities and we detected no significant changes in the stream fish communities associated with partially harvested riparian buffers in either study. This would suggest that timber harvesting in riparian management zones along reaches ≤200 m in length on both sides of the stream that retains RBA ≥ 12.4 ± 1.3 m2 ha−1 or on a single side of the stream that retains RBA ≥ 8.7 ± 1.6 m2 ha−1 may be adequate to protect macroinvertebrate and fish communities in our Minnesota study systems given these specific timber harvesting techniques.

  17. Survey of the marine benthic infauna collected from the United States radioactive waste disposal sites off the Farallon Islands, California. Final report

    International Nuclear Information System (INIS)

    Benthic biological samples were taken in 1977 from the vicinity of the Farallon Islands radioactive waste disposal sites for characterization of the infaunal macroinvertebrates and foraminifera. A total of 120 invertebrate species were collected, of which 75 species (63 percent) were polychaetes. Forty-three of these polychaete species have not previously been reported from depths greater than 1000m. A total of 1044 macroinvertebrate specimens were collected of which 54 percent were polychates. Only the nematods were present at all six benthic stations, but the community structure was dominated by the polychaetes Tauberia gracilis, Allia pulchra, Chaetozone setosa, and Cossura candida. Living and dead foraminifera were reported. The possible role of polychaetes in bioturbation and in the marine food chain is briefly discussed with respect to the various polychaete feeding mechanisms

  18. Biodiversity in Benthic Ecology

    DEFF Research Database (Denmark)

    Friberg, Nikolai; Carl, J. D.

    Foreword: This proceeding is based on a set of papers presented at the second Nordic Benthological Meeting held in Silkeborg, November 13-14, 1997. The main theme of the meeting was biodiversity in benthic ecology and the majority of contributions touch on this subject. In addition, the proceeding...

  19. Aquatic macroinvertebrates of the Jablanica river, Serbia

    Directory of Open Access Journals (Sweden)

    Stefanović Katarina S.

    2009-01-01

    Full Text Available Research on the community of aquatic macroinvertebrates was carried out during 2005 and 2006 at four sampling sites along the Jablanica River, a right-hand tributary of the Kolubara River. Fifty-seven taxa were recorded in the course of the investigation. The most diverse group was Ephemeroptera, followed by Trichoptera and Plecoptera. Members of the Rhitrogena semicolorata group were the most abundant. Our results could be the basis for evaluation of the influence of damming of the Jablanica River on the status of its water and can serve as a model for studying the influ­ence of hydromorphological degradation of aquatic ecosystems.

  20. Intertidal assemblage variation across a subtropical estuarine gradient: How good conceptual and empirical models are?

    Science.gov (United States)

    Morais, Gisele C.; Camargo, Maurício G.; Lana, Paulo

    2016-03-01

    Variation of intertidal macrobenthic structure at multiple spatial scales is still poorly known in tropical and subtropical estuaries. We have assessed the structural responses of intertidal benthic assemblages, expressed by variation in number of species, abundance and assemblage composition, to key environmental drivers in a subtropical estuary from southern Brazil. We have applied a hierarchical sampling design to assess benthic variation at each of several spatial scales, from meters to kilometers, along a marked estuarine gradient. The hypothesis that many benthic variables vary at the largest spatial scale, corresponding to the salinity gradient, was refuted for number of species but not for total abundance and species composition. However, physiological stress to salinity variation, an important environmental driver in estuaries, could not explain by itself macrobenthic distribution along local intertidal flats. Nutrient, organic matter, photosynthetic pigments contents, pH, grain size, silt-clay content and the redox discontinuity layer also varied at the largest spatial scale acting as confounding factors. Thus, overall distribution patterns of intertidal benthic assemblages resulted from a complex interaction among environmental drivers, including salinity.

  1. Habitat specialization in tropical continental shelf demersal fish assemblages.

    Directory of Open Access Journals (Sweden)

    Ben M Fitzpatrick

    Full Text Available The implications of shallow water impacts such as fishing and climate change on fish assemblages are generally considered in isolation from the distribution and abundance of these fish assemblages in adjacent deeper waters. We investigate the abundance and length of demersal fish assemblages across a section of tropical continental shelf at Ningaloo Reef, Western Australia, to identify fish and fish habitat relationships across steep gradients in depth and in different benthic habitat types. The assemblage composition of demersal fish were assessed from baited remote underwater stereo-video samples (n = 304 collected from 16 depth and habitat combinations. Samples were collected across a depth range poorly represented in the literature from the fringing reef lagoon (1-10 m depth, down the fore reef slope to the reef base (10-30 m depth then across the adjacent continental shelf (30-110 m depth. Multivariate analyses showed that there were distinctive fish assemblages and different sized fish were associated with each habitat/depth category. Species richness, MaxN and diversity declined with depth, while average length and trophic level increased. The assemblage structure, diversity, size and trophic structure of demersal fishes changes from shallow inshore habitats to deeper water habitats. More habitat specialists (unique species per habitat/depth category were associated with the reef slope and reef base than other habitats, but offshore sponge-dominated habitats and inshore coral-dominated reef also supported unique species. This suggests that marine protected areas in shallow coral-dominated reef habitats may not adequately protect those species whose depth distribution extends beyond shallow habitats, or other significant elements of demersal fish biodiversity. The ontogenetic habitat partitioning which is characteristic of many species, suggests that to maintain entire species life histories it is necessary to protect corridors of

  2. Macroinvertebrate sampling on Fish Springs National Wildlife Refuge

    Data.gov (United States)

    US Fish and Wildlife Service, Department of the Interior — This document discusses the results of macroinvertebrate sampling that was conducted on Fish Springs National Refuge between May and August 1983. The purpose of...

  3. Benthic macroinvertebrate community structure and distribution in the Ayeyarwady continental shelf, Andaman Sea

    Digital Repository Service at National Institute of Oceanography (India)

    Ansari Z.A.; Furtado, R.; Badesab, S.; Mehta, P.; Thwin, S.

    shelf, Andaman Sea (Figure 1). For the collection of macrofauna a Petersen grab of 0.1 m2 area was operated. All samples were subjected to sieving through a 0.5 mm sieve and animals retained on the sieve were preserved in 5% formalin Rose Bengal... solution on board the ship. Replicate samples were collected as far as possible. In the laboratory the animals were sorted out, enumerated group wise and wet weight biomass taken. Thus total density and total biomass of the different faunal group...

  4. Northwestern Hawaiian Islands Benthic Macroinvertebrate Community Assessment, October 2000 (NODC Accession 0002301)

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — The Northwestern Hawaiian islands were sampled during October 2000 at 63 stations on 9 atolls or islands under the lead of NOAA. This work is affiliated with the...

  5. The choice of a suitable sampler for benthic macroinvertebrates in deep rivers

    OpenAIRE

    Elliott, J. M.; Drake, C. M.; Tullet, P.A.

    1980-01-01

    Both chemical and biological methods are used to assess the water quality of rivers. Many standard physical and chemical methods are now established, but biological procedures of comparable accuracy and versatility are still lacking. This is unfortunate because the biological assessment of water quality has several advantages over physical and chemical analyses. Several groups of organisms have been used to assess water quality in rivers and these include Bacteria, Protozoa, Algae, macrophyte...

  6. Trace Metal Accumulation in Sediments and Benthic Macroinvertebrates before and after Maintenance of a Constructed Wetland

    Science.gov (United States)

    Periodic maintenance of stormwater best management practices (BMP) includes the removal of accumulated sediment. The resulting impact on trace metal concentrations of copper (Cu), lead (Pb), and zinc (Zn) in a constructed stormwater wetland BMP on Staten Island, NY was investiga...

  7. Headwater streams and forest management: does ecoregional context influence logging effects on benthic communities?

    Science.gov (United States)

    Medhurst, R. Bruce; Wipfli, Mark S.; Binckley, Chris; Polivka, Karl; Hessburg, Paul F.; Salter, R. Brion

    2010-01-01

    Effects of forest management on stream communities have been widely documented, but the role that climate plays in the disturbance outcomes is not understood. In order to determine whether the effect of disturbance from forest management on headwater stream communities varies by climate, we evaluated benthic macroinvertebrate communities in 24 headwater streams that differed in forest management (logged-roaded vs. unlogged-unroaded, hereafter logged and unlogged) within two ecological sub-regions (wet versus dry) within the eastern Cascade Range, Washington, USA. In both ecoregions, total macroinvertebrate density was highest at logged sites (P = 0.001) with gathering-collectors and shredders dominating. Total taxonomic richness and diversity did not differ between ecoregions or forest management types. Shredder densities were positively correlated with total deciduous and Sitka alder (Alnus sinuata) riparian cover. Further, differences in shredder density between logged and unlogged sites were greater in the wet ecoregion (logging × ecoregion interaction; P = 0.006) suggesting that differences in post-logging forest succession between ecoregions were responsible for differences in shredder abundance. Headwater stream benthic community structure was influenced by logging and regional differences in climate. Future development of ecoregional classification models at the subbasin scale, and use of functional metrics in addition to structural metrics, may allow for more accurate assessments of anthropogenic disturbances in mountainous regions where mosaics of localized differences in climate are common.

  8. Aquatic macroinvertebrates of the lower Missouri River

    Science.gov (United States)

    Poulton, Barry C.

    2010-01-01

    The U.S. Geological Survey (USGS) Columbia Environmental Research Center (CERC), in cooperation with the U.S. Environmental Protection Agency (USEPA), the U.S. Fish & Wildlife Service (USFWS), and the Missouri Department of Natural Resources (MDNR), has been conducting research on the aquatic macroinvertebrates of the lower Missouri River since the mid-1990s. This research was initiated in response to the need for comprehensive characterization of biological communities inhabiting aquatic habitats in large river systems that have historically been poorly studied. The USGS Status and Trends of Biological Resources Program provided partial funding for pilot studies that began in 1993 when the CERC was part of the USFWS. The purpose of this fact sheet is to provide stakeholders, scientists, management, and the general public with a basic summary of results from studies conducted by the CERC since that time period.

  9. The macroinvertebrates of Magela Creek, Northern Territory

    International Nuclear Information System (INIS)

    The littoral zones of five permanent billabongs in Magela Creek were sampled monthly for macroinvertebrates. Greatest numbers of taxa and individuals were caught in the late wet season and early dry season in the shallow billabongs; in the deep billabongs, seasonal variations were not so marked. These changes appeared to be associated with the development of macrophytes, which offered food and shelter to the invertebrate fauna. The dominant groups were the Chironomidae, Oligochaetae and Ephemeroptera. The seasonal patterns of the catches were sufficiently consistent for future samples to be able to be compared with these initial ones with some confidence that any changes are real. This work is part of a larger study into the biota and water quality of Magela Creek designed to provide data on aquatic communities before mining of the Ranger uranium deposit starts

  10. Life-history strategies in freshwater macroinvertebrates

    NARCIS (Netherlands)

    Verberk, W.C.E.P.; Siepel, H.; Esselink, H.

    2008-01-01

    1. Explaining spatial and temporal differences in species assemblages is a central aim of ecology. It requires a sound understanding of the causal mechanisms underlying the relationship of species with their environment. A species trait is widely acknowledged to be the key that links pattern and pro

  11. Comics as Assemblage

    DEFF Research Database (Denmark)

    Cortsen, Rikke Platz

    the black panel and their spatio-temporal effects comparing various works by the same author or comics by man different artists. Building from this, a separate chapter analyses comics’ structure as a network with combining comics theory by Thierry Groensteen with Manuel DeLanda’s concept of assemblage......This thesis examines the apparent simplicity of comics by exposing some of the layers in which meaning is created in a complex network; it approaches the complexity of comics from the angle of spatio-temporality and separates comics into several spatio-temporal levels that each interacts in the way......-temporality of structure and in turn how this spatio-temporality is imagined through the spatio-temporality of the reader. Using Mikhail M. Bakhtin’s concept of the chronotope, I examine how the configuration of different spatio-temporalities interconnect in the superhero series Top 10. These spatio...

  12. Impacts of Sedimentation from Oil and Gas Development on Stream Macroinvertebrates in Two Adjacent Watersheds of the Allegheny National Forest of Northwestern Pennsylvania

    Energy Technology Data Exchange (ETDEWEB)

    Fritz, K.; Harris, S.; Edenborn, H.M.; Sams, J.

    2011-01-01

    Fritz, Kelley'*, Steven Harris', Harry Edenborn2, and James Sams2. 'Clarion University of Pennsylvania, Clarion, PA 16214, 2National Energy Technology Laboratory, U.S. Dept. Energy, Pittsburgh, PA 15236. Impacts a/Sedimentation/rom Oil and Gas Development on Stream Macroinvertebrates in Two Adjacent Watersheds a/the Allegheny National Forest a/Northwestern Pennsylvania - The Allegheny National Forest (ANF), located in northwestern Pennsy Ivania, is a multiuse forest combining commercial development with recreational and conservation activities. As such, portions of the ANF have been heavily logged and are now the subject of widespread oil and gas development. This rapid increase in oil and gas development has led to concerns about sediment runoff from the dirt and gravel roads associated with development and the potential impact on the aquatic biota of the receiving streams. We examined and compared the benthic macroinvertebrate communities in two adjacent watersheds of similar size and topography in the ANF; the Hedgehog Run watershed has no oil and gas development, while the adjacent Grunder Run watershed has extensive oil and gas development. In Hedgehog and Grunder Run, we collected monthly kicknet samples from riffles and glides at two sites from April to October 2010. At the same intervals, we measured standard water quality parameters, including conductivity and turbidity. Preliminary results have indicated much higher turbidity in Grunder Run, but little difference in the diversity and abundance of benthic macro invertebrates inhabiting the two streams.

  13. Macroalgal Extracts Induce Bacterial Assemblage Shifts and Sublethal Tissue Stress in Caribbean Corals

    OpenAIRE

    Morrow, Kathleen M.; Raphael Ritson-Williams; Cliff Ross; Mark R Liles; Paul, Valerie J

    2012-01-01

    Benthic macroalgae can be abundant on present-day coral reefs, especially where rates of herbivory are low and/or dissolved nutrients are high. This study investigated the impact of macroalgal extracts on both coral-associated bacterial assemblages and sublethal stress response of corals. Crude extracts and live algal thalli from common Caribbean macroalgae were applied onto the surface of Montastraea faveolata and Porites astreoides corals on reefs in both Florida and Belize. Denaturing grad...

  14. Application of "taxocene surrogation" and "taxonomic sufficiency" concepts to fish farming environmental monitoring. Comparison of BOPA index versus polychaete assemblage structure.

    Science.gov (United States)

    Aguado-Giménez, F; Gairín, J I; Martinez-Garcia, E; Fernandez-Gonzalez, V; Ballester Moltó, M; Cerezo-Valverde, J; Sanchez-Jerez, P

    2015-02-01

    "Taxocene surrogation" and "taxonomic sufficiency" concepts were applied to the monitoring of soft bottoms macrobenthic assemblages influenced by fish farming following two approaches. Polychaete assemblage evaluation through multivariate analysis and the benthic index BOPA were compared. Six fish farms along the Spanish Mediterranean coast were monitored. Polychaete assemblage provided a suitable picture of the impact gradient, being correlated with total free sulphides. BOPA did not support the impact gradient described by the polychaete assemblage, providing erroneous categorizations. The inclusion of several polychaete families, which were locally identified as indicative of affection to recalculate BOPA, resulted in an improved diagnosis and correlation with the impact gradient. Nevertheless, frequent misclassifications occurred. These results suggest that the structure of polychaete families, sulphides and granulometry conform an appropriate strategy for fish farming monitoring. Biotic indices need to be specifically designed for concrete activities, and regionally validated, because of the environmental plasticity of benthic invertebrates. PMID:25460059

  15. Guam Community Coral Reef Monitoring Program, Macroinvertebrate Training Surveys in Guam in 2012

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — Guam community members gathered macroinvertebrate within a 25-meter x 2-meter belt transect. Members identified macroinvertebrates to species (when possible),...

  16. UPPER YELLOWSTONE RIVER, MONTANA: MACROINVERTEBRATE DISTRIBUTION AND WATER ANALYSIS 1973-1974

    Science.gov (United States)

    Macroinvertebrate and water chemistry samples were taken at seven stations in the Yellowstone River between August 1973 and August 1974. The stations were located between Gardiner and Laurel, Montana. Macroinvertebrate samples were collected on six, and water chemistry samples on...

  17. Macroinvertebrate and organic matter export from headwater tributaries of a Central Appalachian stream

    Science.gov (United States)

    Headwater streams export organisms and other materials to their receiving streams and macroinvertebrate drift can shape colonization dynamics in downstream reaches while providing food for downstream consumers. Spring-time macroinvertebrate drift and organic matter export was me...

  18. Cryptic biodiversity in streams - a comparison of macroinvertebrate communities based on morphological and DNA barcode identifications

    Science.gov (United States)

    Aquatic ecologists and entomologists have long known that species-level identifications were difficult, if not impossible, for many larval macroinvertebrates collected in streams. This study describes macroinvertebrate (primarily insect) communities from five coastal streams dist...

  19. Cryptic biodiversity in streams: a comparison of macroinvertebrate communities based on morphological and DNA barcode identifications

    Science.gov (United States)

    Species-level identifications are difficult or impossible for many larval aquatic macroinvertebrates. We described the taxonomic composition of macroinvertebrate communities from 5 coastal streams in 3 neighboring catchments in southern California. We compared taxonomic identific...

  20. Abundance and diversity of aquatic macroinvertebrate communities in lakes exposed to Chernobyl-derived ionising radiation

    International Nuclear Information System (INIS)

    Littoral (lake shore) macroinvertebrate communities were studied in eight natural lakes affected by fallout from the Chernobyl accident. The lakes spanned a range in 137Cs contamination from 100 to 15500 kBq m-2 and estimated external dose rates ranged from 0.13 to 30.7 μGy h-1. General linear models were used to assess whether abundance of individuals, taxon richness, Berger-Parker dominance and Shannon-Wiener diversity varied across the lakes. Step-wise multiple regressions were used to relate variation in total abundance, taxon richness, Berger-Parker dominance, Shannon-Wiener diversity, taxon richness within major groups of macroinvertebrates and abundance of the more common individual taxa to the measured environmental characteristics (conductivity, pH, total hardness and phosphate; lake area, lake maximum depth and total external dose) of the lakes. No evidence was found in this study that the ecological status of lake communities has been influenced by radioactive contamination from the Chernobyl accident. Indeed, the most contaminated lake, Glubokoye, contained the highest richness of aquatic invertebrates. Taxon richness in the eight study lakes varied from 22 (Svyatskoe no. 7) to 42 (Glubokoye) which spans a range typical for uncontaminated lakes in the region. Since 90Sr is readily-absorbed by Mollusca, estimated dose rates to this group exceeded those for other invertebrate groups in two lakes (Perstok and Glubokoye). However this study found no association between mollusc diversity or abundance of individual snail species and variation between lakes in the external radiation dose. Indeed Glubokoye, the lake most contaminated by 90Sr, had the highest richness of freshwater snails per sample (an average of 8.9 taxa per sample). - Highlights: → We studied the effect of radiation on macroinvertebrates in Chernobyl affected lakes. → Abundance, taxon richness, Berger-Parker dominance, Shannon-Wiener diversity evaluated. → No relationship between

  1. Abundance and diversity of aquatic macroinvertebrate communities in lakes exposed to Chernobyl-derived ionising radiation

    Energy Technology Data Exchange (ETDEWEB)

    Murphy, J.F. [NERC Centre for Ecology and Hydrology, Wallingford, Oxfordshire, OX10 8BB (United Kingdom); Nagorskaya, L.L. [Institute of Zoology NAS Belarus, 27, Academicheskaya st., 220072, Minsk (Belarus); Smith, J.T., E-mail: Jim.Smith@port.ac.uk [School of Earth and Environmental Sciences, University of Portsmouth, Burnaby Bldg, Burnaby Road, Portsmouth PO1 3QL (United Kingdom)

    2011-07-15

    Littoral (lake shore) macroinvertebrate communities were studied in eight natural lakes affected by fallout from the Chernobyl accident. The lakes spanned a range in {sup 137}Cs contamination from 100 to 15500 kBq m{sup -2} and estimated external dose rates ranged from 0.13 to 30.7 {mu}Gy h{sup -1}. General linear models were used to assess whether abundance of individuals, taxon richness, Berger-Parker dominance and Shannon-Wiener diversity varied across the lakes. Step-wise multiple regressions were used to relate variation in total abundance, taxon richness, Berger-Parker dominance, Shannon-Wiener diversity, taxon richness within major groups of macroinvertebrates and abundance of the more common individual taxa to the measured environmental characteristics (conductivity, pH, total hardness and phosphate; lake area, lake maximum depth and total external dose) of the lakes. No evidence was found in this study that the ecological status of lake communities has been influenced by radioactive contamination from the Chernobyl accident. Indeed, the most contaminated lake, Glubokoye, contained the highest richness of aquatic invertebrates. Taxon richness in the eight study lakes varied from 22 (Svyatskoe no. 7) to 42 (Glubokoye) which spans a range typical for uncontaminated lakes in the region. Since {sup 90}Sr is readily-absorbed by Mollusca, estimated dose rates to this group exceeded those for other invertebrate groups in two lakes (Perstok and Glubokoye). However this study found no association between mollusc diversity or abundance of individual snail species and variation between lakes in the external radiation dose. Indeed Glubokoye, the lake most contaminated by {sup 90}Sr, had the highest richness of freshwater snails per sample (an average of 8.9 taxa per sample). - Highlights: > We studied the effect of radiation on macroinvertebrates in Chernobyl affected lakes. > Abundance, taxon richness, Berger-Parker dominance, Shannon-Wiener diversity evaluated. > No

  2. Effects of a brine discharge over soft bottom Polychaeta assemblage

    Energy Technology Data Exchange (ETDEWEB)

    Pilar-Ruso, Yoana del [Dpto. de Ciencias del Mar y Biologia Aplicada, Universidad de Alicante, Campus de San Vicente del Raspeig, Ap. 99, E-03080, Alicante (Spain)], E-mail: yoana.delpilar@ua.es; Ossa-Carretero, Jose Antonio de la; Gimenez-Casalduero, Francisca; Sanchez-Lizaso, Jose Luis [Dpto. de Ciencias del Mar y Biologia Aplicada, Universidad de Alicante, Campus de San Vicente del Raspeig, Ap. 99, E-03080, Alicante (Spain)

    2008-11-15

    Desalination is a growing activity that has introduced a new impact, brine discharge, which may affect benthic communities. Although the role of polychaetes as indicators to assess organic pollution is well known, their tolerance to salinity changes has not been examined to such a great extent. The aim of this study was to examine the effect of brine discharge over soft bottom polychaete assemblage along the Alicante coast (Southeast Spain) over a two year period. Changes in the polychaete assemblage was analysed using univariate and multivariate techniques. We compared a transect in front of the discharge with two controls. At each transect we sampled at three depths (4, 10 and 15 m) during winter and summer. We have observed different sensitivity of polychaete families to brine discharges, Ampharetidae being the most sensitive, followed by Nephtyidae and Spionidae. Syllidae and Capitellidae showed some resistance initially, while Paraonidae proved to be a tolerant family. - The Polychaete assemblage is affected by the brine discharge of the Alicante desalination plant and we detect different sensitivity levels in polychaete families to brine impact.

  3. Long-Term Impacts on Macroinvertebrates Downstream of Reclaimed Mountaintop Mining Valley Fills in Central Appalachia

    Science.gov (United States)

    Pond, Gregory J.; Passmore, Margaret E.; Pointon, Nancy D.; Felbinger, John K.; Walker, Craig A.; Krock, Kelly J. G.; Fulton, Jennifer B.; Nash, Whitney L.

    2014-10-01

    Recent studies have documented adverse effects to biological communities downstream of mountaintop coal mining and valley fills (VF), but few data exist on the longevity of these impacts. We sampled 15 headwater streams with VFs reclaimed 11-33 years prior to 2011 and sampled seven local reference sites that had no VFs. We collected chemical, habitat, and benthic macroinvertebrate data in April 2011; additional chemical samples were collected in September 2011. To assess ecological condition, we compared VF and reference abiotic and biotic data using: (1) ordination to detect multivariate differences, (2) benthic indices (a multimetric index and an observed/expected predictive model) calibrated to state reference conditions to detect impairment, and (3) correlation and regression analysis to detect relationships between biotic and abiotic data. Although VF sites had good instream habitat, nearly 90 % of these streams exhibited biological impairment. VF sites with higher index scores were co-located near unaffected tributaries; we suggest that these tributaries were sources of sensitive taxa as drifting colonists. There were clear losses of expected taxa across most VF sites and two functional feeding groups (% scrapers and %shredders) were significantly altered. Percent VF and forested area were related to biological quality but varied more than individual ions and specific conductance. Within the subset of VF sites, other descriptors (e.g., VF age, site distance from VF, the presence of impoundments, % forest) had no detectable relationships with biological condition. Although these VFs were constructed pursuant to permits and regulatory programs that have as their stated goals that (1) mined land be reclaimed and restored to its original use or a use of higher value, and (2) mining does not cause or contribute to violations of water quality standards, we found sustained ecological damage in headwaters streams draining VFs long after reclamation was completed.

  4. Consumption of macroinvertebrates by invasive and native gammarids: a comparison

    Directory of Open Access Journals (Sweden)

    Gerhard MAIER

    2005-02-01

    Full Text Available The Ponto-Caspian gammarids Dikerogammarus villosus SOVINSKIJ and Echinogammarus ischnus STEBBING have invaded Central-European streams in the early 1990s. Declines in macroinvertebrates have been observed since the arrival of invasive species. To elucidate the predatory impact of gammarids on the macroinvertebrate community, we conducted laboratory experiments with macroinvertebrate prey taxa and native and invasive gammarids as predators. Dikerogammarus villosus, which is known to be a strong predator, consumed more and a broader range of prey than E. ischnus or the native gammarids, Gammarus pulex L. and Gammarus roeseli GERVAIS. Echinogammarus ischnus consumed a somewhat higher amount of prey organisms than G. pulex and a higher number and a broader range than G. roeseli. Adult D. villosus consumed up to 25 mg macroinvertebrate biomass (wet weight per day which corresponds to approximately 1/3 of their own biomass. Chironomid larvae were preferred by all gammarids tested. Taking into account that gammarids density may surpass 1000 ind m-2, our results suggest that the predatory behaviour of invasive gammarids, in particular of D. villosus, may have contributed to the decline of some macroinvertebrate taxa in some European streams.

  5. Aquatic macroinvertebrates and water quality in Sandia Canyon

    International Nuclear Information System (INIS)

    In 1990, field studies of water quality and stream macroinvertebrate communities were initiated in Sandia Canyon at Los Alamos National Laboratory. The studies were designed to establish baseline data and to determine the effects of routine discharges of industrial and sanitary waste. Water quality measurements were taken and aquatic macroinvertebrates sampled at three permanent stations within the canyon. Two of the three sample stations are located where the stream regularly receives industrial and sanitary waste effluents. These stations exhibited a low diversity of macroinvertebrates and slightly degraded water quality. The last sample station, located approximately 0.4 km (0.25 mi) downstream from the nearest wastewater outfall, appears to be in a zone of recovery where water quality parameters more closely resemble those found in natural streams in the Los Alamos area. A large increase in macroinvertebrate diversity was also observed at the third station. These results indicate that effluents discharged into Sandia Canyon have a marked effect on water quality and aquatic macroinvertebrate communities

  6. WATER QUALITY EVALUATION OF CRIŞUL ALB AND CRIŞUL NEGRU RIVERS CATCHMENTS, FROM CODRU-MOMA MOUNTAINS (WEST OF ROMANIA, USING BENTHIC INVERTEBRATES COMMUNITIES

    Directory of Open Access Journals (Sweden)

    Andreea VARGA

    2010-01-01

    Full Text Available Water quality evaluation of the two watersheds involved the collection of thirteen samples from the tributaries of Crişul Alb and Crişul Negru rivers. The samples were collected in june 2010 with a benthic net, which had the mesh size of 250 µm, by disturbing the substrate, being thus qualitative samples. To get an overview, a series of physical-chemical parameters (water temperature, pH, oxygen, conductivity, cyanide, nitrates, nitrites, phosphates was studied in parallel with the study of benthic community. In most of the sampling points the major group of benthic macroinvertebrates were found and in some EPT group (Ephemeroptera, Plecoptera, Trichoptera prevailed even, which is known as a clean freshwater group, sensitive to pollution and human impact.

  7. Effects of the “Run-of-River” Hydro Scheme on Macroinvertebrate Communities and Habitat Conditions in a Mountain River of Northeastern China

    Directory of Open Access Journals (Sweden)

    Haoran Wang

    2016-01-01

    Full Text Available The main objective of this study was to quantify the impacts of the run of river (ROR scheme on the instream habitat and macroinvertebrate community. We sampled the macroinvertebrate assemblages and collected the habitat variables above and below an ROR hydropower plant: Aotou plant in the Hailang River, China. The effects of the ROR scheme on habitat conditions were examined using regulation-related variables, most of which, particularly the hydrological variables and substrate composition, presented spatial variations along the downstream direction, contributing to heterogeneous conditions between reaches. The macroinvertebrate richness, the density and the diversity metrics showed significant decreases in the “depleted” reach compared with the upper and lower reaches. Approximately 75% of reach-averaged densities and 50% of taxa richness suffered decreases in the “depleted” reach compared with the upper reach. Furthermore, functional feeding groups also showed distinct site differences along the channel. The relative abundance of both collector-gatherers and the scrapers reduced considerably at the “depleted” sites, particularly at the site immediately downstream of the weir. The total variance in the the functional feeding group (FFG data explained by Canonical correlation analysis (CCA was more than 81.4% and the high-loadings factors were depth, flow velocity, DO and substrate composition. We demonstrated that flow diversion at the 75% level and an in-channel barrier, due to the ROR scheme, are likely to lead to poor habitat conditions and decrease both the abundance and the diversity of macroinvertebrates in reaches influenced by water diversion.

  8. Assessing macroinvertebrate biodiversity in freshwater ecosystems: Advances and challenges in dna-based approaches

    Science.gov (United States)

    Pfrender, M.E.; Ferrington, L.C., Jr.; Hawkins, C.P.; Hartzell, P.L.; Bagley, M.; Jackson, S.; Courtney, G.W.; Larsen, D.P.; Creutzburg, B.R.; Levesque, C.A.; Epler, J.H.; Morse, J.C.; Fend, S.; Petersen, M.J.; Ruiter, D.; Schindel, D.; Whiting, M.

    2010-01-01

    Assessing the biodiversity of macroinvertebrate fauna in freshwater ecosystems is an essential component of both basic ecological inquiry and applied ecological assessments. Aspects of taxonomic diversity and composition in freshwater communities are widely used to quantify water quality and measure the efficacy of remediation and restoration efforts. The accuracy and precision of biodiversity assessments based on standard morphological identifications are often limited by taxonomic resolution and sample size. Morphologically based identifications are laborious and costly, significantly constraining the sample sizes that can be processed. We suggest that the development of an assay platform based on DNA signatures will increase the precision and ease of quantifying biodiversity in freshwater ecosystems. Advances in this area will be particularly relevant for benthic and planktonic invertebrates, which are often monitored by regulatory agencies. Adopting a genetic assessment platform will alleviate some of the current limitations to biodiversity assessment strategies. We discuss the benefits and challenges associated with DNA-based assessments and the methods that are currently available. As recent advances in microarray and next-generation sequencing technologies will facilitate a transition to DNA-based assessment approaches, future research efforts should focus on methods for data collection, assay platform development, establishing linkages between DNA signatures and well-resolved taxonomies, and bioinformatics. ?? 2010 by The University of Chicago Press.

  9. Meander reconnection method determines restoration success for macroinvertebrate communities in a German lowland river

    DEFF Research Database (Denmark)

    Lorenz, Stefan; Leszinski, Marc; Graeber, Daniel

    2016-01-01

    meander, blocked main channel) and a partially reconnected meander (opened downstream, pipe bypass from main channel upstream, still open main channel) for macroinvertebrate communities in a German lowland river. Immediately upon reconnection of the two meanders, habitat diversity and macroinvertebrates...... were recorded for three years with sampling in spring and in summer each year. The results of a principal response curve analysis show that the macroinvertebrate community in the fully reconnected meander reflected main channel reference conditions after 1.5 years. The macroinvertebrate community...... sufficiently affect the basic hydromorphological requirements to achieve reference macroinvertebrate community composition. Measures including hydromorphological conditions are therefore recommended for employment in environmental management....

  10. Polychlorinated biphenyls and cyclic pesticides in sediments and macroinvertebrates from the coastal regions of different climatological zones

    International Nuclear Information System (INIS)

    The present study contributed towards establishing the status of a tropical and a moderate latitude marine ecosystem in terms of the concentration of anthropogenic, lipid associated, cyclic, halogenated hydrocarbons in surface sediments and benthic macroinvertebrates. Samples were obtained from the coastal region and the continental slope of Kenya (Indian Ocean), the Dutch coastal region and the continental shelf of the North Sea, and a bay area of Curacao (Netherlands Antilles, Caribbean). In surface sediments (Kenya), congeners CB28, CB52, CB101, CB118, CB153, CB138 and CB180, and the pesticides alpha-HCH and gamma-HCH, dieldrin, endrin and members of the DDT family were not identified, except in the estuarine zone of the Sabaki River. In North Sea surface sediment, the characteristics PCB pattern was always determined, and concentrations were particularly enhanced in sediment from the river mouths. Also, alpha-HCH, p,p'-DDD and p,p'-DDE were quantified in most samples. Regarding benthic invertebrates, CBs and p,p'-DDE were quantified. Some samples showed particularly enhanced levels in bivalve molluscs and certain penaeid prawns the Kenyan coastal region. The high levels present in the digestive (pyloric caeca) and reproductive (gonad) organs of seastar from the North Sea confirmed distinct concentration gradients. Sponges and tunicates from the bay area of Curacao accumulated CBs and p,p'-DDE, but not at very high concentrations. (author). 23 refs, 2 figs, 7 tabs

  11. Diel variation in near-shore great lakes fish assemblages and implications for assessment sampling and coastal management

    Science.gov (United States)

    McKenna, J.E., Jr.

    2008-01-01

    I compared fish assemblages captured in three different microhabitats (shoreline, pelagic near-shore, and benthic near-shore) during day and night fishing in different protection (inside bay or tributary vs. outside in Lake Ontario proper) and turbidity regimes of four near-shore areas of Lake Ontario. The effects of diel movement and availability to gear were clearly evident. Fish assemblages were consistently and significantly more diverse at night than during the day, with nighttime assemblages often being supersets of daytime assemblages. Evidence for a turbidity effect was much weaker than the effects of nocturnal movements and changes in availability to the gear associated with darkness. Nighttime sampling is more likely to capture the full array of species in near-shore areas of the Great Lakes than daytime sampling.

  12. Spatial Variability of Benthic-Pelagic Coupling in an Estuary Ecosystem: Consequences for Microphytobenthos Resuspension Phenomenon

    Science.gov (United States)

    Ubertini, Martin; Lefebvre, Sébastien; Gangnery, Aline; Grangeré, Karine; Le Gendre, Romain; Orvain, Francis

    2012-01-01

    The high degree of physical factors in intertidal estuarine ecosystem increases material processing between benthic and pelagic compartments. In these ecosystems, microphytobenthos resuspension is a major phenomenon since its contribution to higher trophic levels can be highly significant. Understanding the sediment and associated microphytobenthos resuspension and its fate in the water column is indispensable for measuring the food available to benthic and pelagic food webs. To identify and hierarchize the physical/biological factors potentially involved in MPB resuspension, the entire intertidal area and surrounding water column of an estuarine ecosystem, the Bay des Veys, was sampled during ebb tide. A wide range of physical parameters (hydrodynamic regime, grain size of the sediment, and suspended matter) and biological parameters (flora and fauna assemblages, chlorophyll) were analyzed to characterize benthic-pelagic coupling at the bay scale. Samples were collected in two contrasted periods, spring and late summer, to assess the impact of forcing variables on benthic-pelagic coupling. A mapping approach using kriging interpolation enabled us to overlay benthic and pelagic maps of physical and biological variables, for both hydrological conditions and trophic indicators. Pelagic Chl a concentration was the best predictor explaining the suspension-feeders spatial distribution. Our results also suggest a perennial spatio-temporal structure of both benthic and pelagic compartments in the ecosystem, at least when the system is not imposed to intense wind, with MPB distribution controlled by both grain size and bathymetry. The benthic component appeared to control the pelagic one via resuspension phenomena at the scale of the bay. Co-inertia analysis showed closer benthic-pelagic coupling between the variables in spring. The higher MPB biomass observed in summer suggests a higher contribution to filter-feeders diets, indicating a higher resuspension effect in

  13. Effects of coral reef benthic primary producers on dissolved organic carbon and microbial activity.

    Directory of Open Access Journals (Sweden)

    Andreas F Haas

    Full Text Available Benthic primary producers in marine ecosystems may significantly alter biogeochemical cycling and microbial processes in their surrounding environment. To examine these interactions, we studied dissolved organic matter release by dominant benthic taxa and subsequent microbial remineralization in the lagoonal reefs of Moorea, French Polynesia. Rates of photosynthesis, respiration, and dissolved organic carbon (DOC release were assessed for several common benthic reef organisms from the backreef habitat. We assessed microbial community response to dissolved exudates of each benthic producer by measuring bacterioplankton growth, respiration, and DOC drawdown in two-day dark dilution culture incubations. Experiments were conducted for six benthic producers: three species of macroalgae (each representing a different algal phylum: Turbinaria ornata--Ochrophyta; Amansia rhodantha--Rhodophyta; Halimeda opuntia--Chlorophyta, a mixed assemblage of turf algae, a species of crustose coralline algae (Hydrolithon reinboldii and a dominant hermatypic coral (Porites lobata. Our results show that all five types of algae, but not the coral, exuded significant amounts of labile DOC into their surrounding environment. In general, primary producers with the highest rates of photosynthesis released the most DOC and yielded the greatest bacterioplankton growth; turf algae produced nearly twice as much DOC per unit surface area than the other benthic producers (14.0±2.8 µmol h⁻¹ dm⁻², stimulating rapid bacterioplankton growth (0.044±0.002 log10 cells h⁻¹ and concomitant oxygen drawdown (0.16±0.05 µmol L⁻¹ h⁻¹ dm⁻². Our results demonstrate that benthic reef algae can release a significant fraction of their photosynthetically-fixed carbon as DOC, these release rates vary by species, and this DOC is available to and consumed by reef associated microbes. These data provide compelling evidence that benthic primary producers differentially influence

  14. Characterizing lentic freshwater fish assemblages using multiple sampling methods

    Science.gov (United States)

    Fischer, Jesse R.; Quist, Michael

    2014-01-01

    Characterizing fish assemblages in lentic ecosystems is difficult, and multiple sampling methods are almost always necessary to gain reliable estimates of indices such as species richness. However, most research focused on lentic fish sampling methodology has targeted recreationally important species, and little to no information is available regarding the influence of multiple methods and timing (i.e., temporal variation) on characterizing entire fish assemblages. Therefore, six lakes and impoundments (48–1,557 ha surface area) were sampled seasonally with seven gear types to evaluate the combined influence of sampling methods and timing on the number of species and individuals sampled. Probabilities of detection for species indicated strong selectivities and seasonal trends that provide guidance on optimal seasons to use gears when targeting multiple species. The evaluation of species richness and number of individuals sampled using multiple gear combinations demonstrated that appreciable benefits over relatively few gears (e.g., to four) used in optimal seasons were not present. Specifically, over 90 % of the species encountered with all gear types and season combinations (N = 19) from six lakes and reservoirs were sampled with nighttime boat electrofishing in the fall and benthic trawling, modified-fyke, and mini-fyke netting during the summer. Our results indicated that the characterization of lentic fish assemblages was highly influenced by the selection of sampling gears and seasons, but did not appear to be influenced by waterbody type (i.e., natural lake, impoundment). The standardization of data collected with multiple methods and seasons to account for bias is imperative to monitoring of lentic ecosystems and will provide researchers with increased reliability in their interpretations and decisions made using information on lentic fish assemblages.

  15. National Benthic Infaunal Database (NBID)

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — The NBID is a quantitative database on abundances of individual benthic species by sample and study region, along with other synoptically measured environmental...

  16. Benthic fauna of mangrove environment

    Digital Repository Service at National Institute of Oceanography (India)

    Parulekar, A.H.

    distribution of benthic communities in mangrove environment is governEd. by tidal amplitude, light penetration, nature of substratum and distance from the sea. The littoral zone, neritic zone, Barnacle-oyster zone, Uca zone, Polychaeta zone have been delineated...

  17. NEPR Benthic Habitat Map 2015

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — This benthic habitat map was created from a semi-automated habitat mapping process, using a combination of bathymetry, satellite imagery, aerial imagery and...

  18. Combining taxonomy and function in the study of stream macroinvertebrates

    Directory of Open Access Journals (Sweden)

    Kenneth W. Cummins

    2016-03-01

    Full Text Available Over the last fifty years, research on freshwater macroinvertebrates has been driven largely by the state of the taxonomy of these animals. In the great majority of studies conducted during the 2000s macroinvertebrates have been operationally defined by investigators as invertebrates retained by a 250 μ mesh in field sampling devices. Significant advances have been and continue to be made in developing ever more refined keys to macroinvertebrate groups. The analysis by function is a viable alternative when advances in macroinvertebrate ecological research is restricted by the level of detail in identifications. Focus on function, namely adaptations of macroinvertebrates to habitats and the utilization of food resources, has facilitated ecological evaluation of freshwater ecosystems (Functional feeding groups; FFG. As the great stream ecologist Noel Hynes observed, aquatic insects around the world exhibit similar morphologies and behaviors, even though they are in very different taxonomic groups. This is the basis for the FFG analysis that was initially developed in the early 1970s. FFG analysis applies taxonomy only to the level of detail that allows assignment to one of six FFG categories: scrapers adapted to feed on periphyton, detrital shredders adapted to feed on coarse (CPOM riparian-derived plant litter that has been colonized by microbes, herbivore shredders that feed on live, rooted aquatic vascular plants, filtering collectors adapted to remove fine particle detritus (FPOM from the water column, gathering collectors adapted to feed on FPOM where it is deposited on surfaces or in crevices in the sediments, and predators that capture live prey. The interacting roles of these FFGs in stream ecosystems were originally depicted in a conceptual model. Thus, there are a limited number of adaptations exhibited by stream macroinvertebrates that exploit these habitats and food resources. This accounts for the wide range of macroinvertebrate taxa

  19. Disentangling the responses of boreal stream assemblages to low stressor levels of diffuse pollution and altered channel morphology.

    Science.gov (United States)

    Turunen, Jarno; Muotka, Timo; Vuori, Kari-Matti; Karjalainen, Satu Maaria; Rääpysjärvi, Jaana; Sutela, Tapio; Aroviita, Jukka

    2016-02-15

    Non-point diffuse pollution from land use and alteration of hydromorphology are among the most detrimental stressors to stream ecosystems. We explored the independent and interactive effects of morphological channel alteration (channelization for water transport of timber) and diffuse pollution on species richness and community structure of four organism groups in boreal streams: diatoms, macrophytes, macroinvertebrates, and fish. Furthermore, the effect of these stressors on stream condition was evaluated by Ecological Quality Ratios (EQR) from the national Water Framework Directive (WFD) assessment system. We grouped 91 study sites into four groups that were impacted by either diffuse pollution or hydromorphological alteration, by both stressors, or by neither one. Macroinvertebrate richness was reduced by diffuse pollution, whereas other biological groups were unaltered. Hydromorphological modification had no effect on taxon richness of any of the assemblages. Community structure of all groups was significantly affected by diffuse pollution but not by hydromorphology. Similarly, EQRs indicated negative response by diatoms, macroinvertebrates and fish to diffuse pollution, but not to hydromorphological alteration. Agricultural diffuse pollution thus affected species identities and abundances rather than taxonomic richness. Our results suggest that channelization of boreal streams for timber transport has not altered hydromorphological conditions sufficiently to have a strong impact on stream biota, whereas even moderate nutrient enrichment may be ecologically harmful. Controlling diffuse pollution and associated land use stressors should be prioritized over restoration of in-stream habitat structure to improve the ecological condition of boreal streams. PMID:26706766

  20. Structure and dynamics of a benthic trophic web in a Mediterranean seasonal stream

    Directory of Open Access Journals (Sweden)

    Patrizia Elena Vannucchi

    2013-10-01

    Full Text Available In this work we present the results of a study conducted on the benthic macroinvertebrate community of a Southern Spain seasonal stream over a year. We constructed the food web focusing on the benthic fauna and we studied the ecology and dynamics of the community in terms of trophic resources. The benthic trophic web was composed by 35 families; these were not all present at the same time, but were incorporating and disappearing throughout the study period. Connectance between trophospecies varied from 0.24 to 0.59. The functional feeding group (FFG composition of the community turned out to be fairly constant with time with a predominance of scrapers and collector-gatherers. Furthermore, data obtained from the Bray-Curtis measure and the niche overlap study, evidence the stability of the stream from a trophic point of view. Rather widespread is omnivory that plays an important role in the survival of some families. We compared the results of the trophic web study with those of other temporary streams of the same region of Southern Spain.

  1. A comparison of macroinvertebrate and habitat methods of data collection in the Little Colorado River Watershed, Arizona 2007

    Science.gov (United States)

    Spindler, Patrice; Paretti, Nick V.

    2007-01-01

    attribute for both datasets in classifying IBI scores into assessment categories. Habitat measurements generated from EMAP and ADEQ methods were also significantly correlated; 13 of 16 habitat measures were significantly correlated (p These results indicate the two sampling methods for macroinvertebrates and habitat data were very similar in terms of bioassessment results and stressors. While the bioassessment category was not identical for all sites, overall the assessments were significantly correlated, providing similar bioassessment results for the cold water streams used in this study. The findings of this study indicate that ADEQ can utilize either a riffle-based sampling methodology or a multi-habitat sampling approach in cold water streams as both yield similar results relative to the macroinvertebrate assemblage. These results will allow for use of either macroinvertebrate dataset to determine water quality standards compliance with the ADEQ Indexes of Biological Integrity, for which threshold values were just recently placed into the Arizona Surface Water Quality Standards. While this survey did not include warm water desert streams of Arizona, we would predict that EMAP and ADEQ sampling methodologies would provide similar bioassessment results and would not be significantly different, as we have found that the percent riffle habitat in cold and warm water perennial, wadeable streams is not significantly different. However, a comparison study of sampling methodologies in warm water streams should be conducted to confirm the predicted similarity of bioassessment results. ADEQ will continue to implement a monitoring strategy that includes probabilistic monitoring for a statewide ecological assessment of stream conditions. Conclusions from this study will guide decisions regarding the most appropriate sampling methods for future probabilistic monitoring sample plans.

  2. Study of aquatic macroinvertebrate communities exposed to buckeye reclamation landfill drainage wastes

    International Nuclear Information System (INIS)

    The Buckeye Reclamation Landfill (BRL), a Superfund site, incorporates approximately 50 acres of a 658 acre tract of land. The BRL consists of past underground mining voids, including some surface-mined lands, and mine refuse piles from processed bituminous coal. The area was subsequently used as a nonhazardous public and municipal solid waste landfill, and industrial sludge and liquid wastes were also deposited in an impoundment in the northern section of the landfill. The entire landfill area was completely covered with soil and revegetated in the late 1980's and early 1990's. The BRL produces acidic and highly mineralized drainage causing a widespread problem of serious mine drainage pollution in the watershed. A study was undertaken to assess the exposure of pollutants to the macroinvertebrate assemblages and to determine the extent of pollution of the BRL watershed. Samples were collected from ten sites in 1995. Nine systematic and spatial transect samples were taken at each collection site for macroinverbrates with a 595 microm mesh, modified kick net from riffle/run and glide/pool habitats of streams above and below the BRL watershed. All macroinverbrates were identified to the lowest taxonomic level possible. The levels for total Zn ranged from 22--604 microg/L; pH ranged from 4.4 to 8.1. The data distinguished the exposed sites receiving landfill leachates and sedimentation runoff from the less impacted sites

  3. Mesophotic reef fish assemblages of the remote St. Peter and St. Paul's Archipelago, Mid-Atlantic Ridge, Brazil

    Science.gov (United States)

    Rosa, Marcos Rogerio; Alves, Aline Cristina; Medeiros, Diego Valverde; Coni, Ericka Oliveira Cavalcanti; Ferreira, Camilo Moitinho; Ferreira, Beatrice Padovani; de Souza Rosa, Ricardo; Amado-Filho, Gilberto Menezes; Pereira-Filho, Guilherme Henrique; de Moura, Rodrigo Leão; Thompson, Fabiano Lopes; Sumida, Paulo Yukio Gomes; Francini-Filho, Ronaldo Bastos

    2016-03-01

    Mesophotic reef fish assemblages (30-90 m depth) of the small and remote St. Peter and St. Paul's Archipelago (SPSPA), Mid-Atlantic Ridge, Brazil, were characterized using remotely operated vehicles. Ordination analyses identified distinct fish assemblages in the upper (30-50 m) and lower (50-90 m) mesophotic zones, the former characterized by high abundances of species that are also abundant at euphotic reefs ( Caranx lugubris, Melichthys niger, Stegastes sanctipauli and Chromis multilineata) and the latter dominated by two mesophotic specialists ( Prognathodes obliquus and Chromis enchrysura). Planktivores dominated fish assemblages, particularly in the upper mesophotic zone, possibly due to a greater availability of zooplankton coming from the colder Equatorial Undercurrent in mesophotic depths of the SPSPA. Turf algae, fleshy macroalgae and scleractinian corals dominated benthic assemblages between 30 and 40 m depth, while bryozoans, black corals and sponges dominated between 40 and 90 m depth. Canonical correspondence analysis explained 74 % of the relationship between environmental characteristics (depth, benthic cover and complexity) and structure of fish assemblages, with depth as the most important independent variable. Juveniles of Bodianus insularis and adults of P. obliquus and C. enchrysura were clearly associated with branching black corals ( Tanacetipathes spp.), suggesting that black corals play key ecological roles in lower mesophotic reefs of the SPSPA. Results from this study add to the global database about mesophotic reef ecosystems (MREs) and provide a baseline for future evaluations of possible anthropogenic and natural disturbances on MREs of the SPSPA.

  4. Planktonic and benthic foraminiferal biostratigraphy of the Middle Eocene-Lower Miocene successions from the Sivas Basin (Central Anatolia, Turkey)

    Science.gov (United States)

    Hakyemez, Aynur; Özgen-Erdem, Nazire; Kangal, Özgen

    2016-02-01

    Planktonic and benthic foraminifera are described from the Middle Eocene-Lower Miocene successions in the Sivas Basin, Central Anatolia. An integrated foraminiferal zonation provides new age assignments in terms of a great number of taxa for the studied sections. Four biostratigraphical intervals are first recorded based on the concurrent ranges of sporadically occurring but well preserved planktonic foraminiferal assemblages. The first interval characterized by the co-occurrences of Acarinina bullbrooki, Truncorotaloides topilensis and Turborotalia cerroazulensis is referable to the E11 Zone of late Lutetian-early Bartonian. An assemblage yielding Paragloborotalia opima accompanied by Globigerinella obesa forms a basis for the late Chattian O5 Zone. The successive interval corresponds to the late Chattian O6 Zone indicated by the presence of Globigerina ciperoensis and Globigerinoides primordius along with the absence of Paragloborotalia opima. The early Aquitanian M1 Zone can be tentatively defined based mainly on the assemblage of Globigerina, Globigerinella, Globoturborotalita and Tenuitella. The biostratigraphical data obtained from the benthic foraminifera assign the studied sections to the SBZ 21-22, SBZ 23 and SBZ 24 ranging in age from Rupelian to Aquitanian. The SBZ 23 and 24 are well constrained biozones by the occurrences of Miogypsinella complanata and Miogypsina gunteri, respectively, whereas the SBZ 21-22 defined by nummulitids and lepidocylinids in the Tethyan Shallow Benthic Zonation is characterized dominantly by peneroplids, soritids and miliolids in the studied sections. Benthic foraminiferal assemblages suggest different paleoenvironments covering lagoon, algal reef and shallow open marine whereas planktonic foraminifera provides evidence for relatively deep marine settings on the basis of assemblages characterized by a mixture of small-sized simple and more complex morphogroups indicative for intermediate depths of the water column.

  5. Soil macroinvertebrates along a successional gradient in central Florida

    Czech Academy of Sciences Publication Activity Database

    Frouz, Jan; Ali, A.

    2004-01-01

    Roč. 87, č. 3 (2004), s. 386-390. ISSN 0015-4040 Institutional research plan: CEZ:AV0Z6066911 Keywords : soil macroinvertebrates * successional gradient * central Florida Subject RIV: EH - Ecology, Behaviour Impact factor: 0.786, year: 2004

  6. Stream macroinvertebrate occurrence along gradients in organic pollution and eutrophication

    DEFF Research Database (Denmark)

    Friberg, Nikolai; Skriver, Jens; Larsen, Søren Erik; Pedersen, Morten Lauge; Buffagni, Andrea

    2010-01-01

    We analysed a large number of concurrent samples of macroinvertebrate communities and chemical indicators of eutrophication and organic pollution [total-P, total-N, NH4-N, biological oxygen demand (BOD5)] from 594 Danish stream sites. Samples were taken over an 11-year time span as part of the...

  7. Are sugarcane leaf-detritus well colonized by aquatic macroinvertebrates?

    Directory of Open Access Journals (Sweden)

    Luciene Aparecida Leite-Rossi

    2012-09-01

    Full Text Available AIM: The aim was to compare the kinetics of decomposition and the colonization of leaf litter of two plant species, the native Talauma ovata (pinha-do-brejo and the exotic Saccharum officinarum (sugarcane, by aquatic macroinvertebrates; METHODS: From each substrate, three recipients of colonization were taken from a stream, and the specimens identified to the lowest taxonomic level on days 7, 15, 34, 44, 61 and 75. The debris was weighed at the beginning and end of the experiment and determined their cell wall fractions; RESULTS: The coefficients of mineralization indicated higher velocity decay of organic matter refractory in T. ovata. There was no difference in taxonomic structure of macroinvertebrates, between the two substrates, but the community exhibited distinct functional feeding groups in the peak of colonization, with a greater number of shredders in T. ovata. The successive states of decomposition of the two plant detritus showed distinct macroinvertebrate densities; CONCLUSIONS: The amount and state of the plant biomass were important factors influencing the density and diversity of the macroinvertebrate fauna throughout the process of organic decomposition.

  8. Qualitative Macroinvertebrate Assessment of Crouch Branch, June 1999

    Energy Technology Data Exchange (ETDEWEB)

    Specht, W.L.

    1999-11-05

    An assessment of the macroinvertebrate community of Crouch Branch was performed in June 1999 to determine if effluent from the H-02 outfall is impairing the quality of the stream. Concurrent samples were collected for metals analyses (copper and zinc). The results of the study indicate that the stream is most impaired just downstream from the H-02 outfall and that the quality of the stream biota improves with increasing distance from the outfall. Conversely, macroinvertebrate habitat quality is best just downstream from the H-02 outfall. The midreaches of the stream contain very poor habitat quality, and the lower reaches of the stream, contain habitat of intermediate quality. Although much of the stream has degraded habitat due to channel erosion and scouring, there is strong evidence to suggest that the impairment is due to elevated concentrations of copper and zinc that are present in the H-02 effluent. A comparison of macroinvertebrate data collected in 1997 to the data collected in this study indicates that the macroinvertebrate community of Crouch Branch has improved markedly in the last two years.

  9. Qualitative Macroinvertebrate Assessment of Crouch Branch, June 1999

    International Nuclear Information System (INIS)

    An assessment of the macroinvertebrate community of Crouch Branch was performed in June 1999 to determine if effluent from the H-02 outfall is impairing the quality of the stream. Concurrent samples were collected for metals analyses (copper and zinc). The results of the study indicate that the stream is most impaired just downstream from the H-02 outfall and that the quality of the stream biota improves with increasing distance from the outfall. Conversely, macroinvertebrate habitat quality is best just downstream from the H-02 outfall. The midreaches of the stream contain very poor habitat quality, and the lower reaches of the stream, contain habitat of intermediate quality. Although much of the stream has degraded habitat due to channel erosion and scouring, there is strong evidence to suggest that the impairment is due to elevated concentrations of copper and zinc that are present in the H-02 effluent. A comparison of macroinvertebrate data collected in 1997 to the data collected in this study indicates that the macroinvertebrate community of Crouch Branch has improved markedly in the last two years

  10. Public Sphere as Digital Assemblage

    DEFF Research Database (Denmark)

    Salovaara-Moring, Inka

    the 1990s onwards digitalization brought concepts of network and complexity into the theoretical discourse. This relational turn changed the social ontology of the public sphere into a dynamic and complex system, erasing the division between the fields of reality (the world), representation (discourse......), and subjectivity (agency). This changed the public sphere into an assemblage consisting of both human and non-human actors interactingin a highly dynamic, networked environment. This paper proposes a framework for considering this new materiality in the field of the public sphere: the assemblage and complexity...

  11. Diversity, distribution and population size structure of deep Mediterranean gorgonian assemblages (Menorca Channel, Western Mediterranean Sea)

    Science.gov (United States)

    Grinyó, Jordi; Gori, Andrea; Ambroso, Stefano; Purroy, Ariadna; Calatayud, Clara; Dominguez-Carrió, Carlos; Coppari, Martina; Lo Iacono, Claudio; López-González, Pablo J.; Gili, Josep-Maria

    2016-06-01

    Gorgonians are a key group of organisms in benthic marine communities with a wide bathymetric and geographical distribution. Although their presence on continental shelves and slopes has been known for more than 100 years, knowledge concerning the ecology of deep gorgonian species is still in a very preliminary stage. To overcome this situation, gorgonian assemblages located at 40-360 m depth were studied over a large geographical area on the continental shelf and upper slope of the Menorca Channel (Western Mediterranean Sea). A quantitative analysis of video transects recorded by a manned submersible and a remotely operated vehicle, were used to examine the diversity, distribution and demography of gorgonian species. Results showed high gorgonian diversity within this depth range (a total of nine species were observed) compared to Mediterranean coastal areas. Gorgonian assemblages on the continental shelf and upper slope were mostly monospecific (respectively 73% and 76% of occupied sampling units contained one single species), whereas shelf edge assemblages were highly multispecific (92% of occupied sampling units contained several species). This contrasts with the monospecificity of Mediterranean coastal gorgonian assemblages. Gorgonian populations on the continental shelf were mostly dominated by small colonies (88% of measured colonies) with few intermediate and large colonies (12% of measured colonies). In deeper areas small colonies were still dominant (60% of measured colonies), but intermediate and large colonies were much more abundant (40% of measured colonies). This suggests high recruitment rates on the continental shelf, but perturbations (trammel nets, long lines and strong storms) may limit the presence of intermediate and large colonies. Conversely, on the shelf edge and upper slope a more stable environment may allow colonies to reach larger dimensions. The identification and ecological characterization of these deep assemblages further extends

  12. Benthic foraminifera at the Cretaceous-Tertiary boundary around the Gulf of Mexico

    Science.gov (United States)

    Alegret, Laia; Molina, Eustoquio; Thomas, Ellen

    2001-10-01

    Cretaceous-Tertiary (K-T) boundary sections in northeastern Mexico contain marly formations separated by a controversial clastic unit. Benthic foraminifera in seven sections indicate middle and lower bathyal depths of deposition for the marls, with the exception of the upper bathyal northernmost section. Mixed neritic-bathyal faunas were present in the clastic unit, indicating redeposition in the deep basin by mass-wasting processes resulting from the K-T bolide impact in the Gulf of Mexico. Benthic foraminifera in the Mexican sections, and at other deep-sea locations, were not subject to major extinction at the time of impact, but there were temporary changes in assemblage composition. Benthic faunas indicate well- oxygenated bottom waters and mesotrophic conditions during the late Maastrichtian and increased food supply during the latest Maastrichtian. The food supply decreased drastically just after the K-T boundary, possibly because of the collapse of surface productivity. Cretaceous and early Paleogene benthic foraminifera, however, did not exhibit the benthic-pelagic coupling of present-day faunas, as documented by the lack of significant extinction at the K-T collapse of surface productivity. Much of the food supplied to the benthic faunas along this continental margin might have been refractory material transported from land or shallow coastal regions. The decrease in food supply at the K-T boundary might be associated with the processes of mass wasting, which removed surface, food-rich sediment. Benthic faunas show a staggered pattern of faunal recovery in the lowermost Paleogene, consistent with a staged recovery of the vertical organic flux but also with a gradual buildup of organic matter in the sediment.

  13. Strong pathways for incorporation of terrestrially derived organic matter into benthic communities

    Science.gov (United States)

    McLeod, Rebecca J.; Wing, Stephen R.

    2009-05-01

    In Fiordland, New Zealand, large volumes of organic matter are deposited into the marine environment from pristine forested catchments. Analyses of δ15N, δ13C and δ34S were employed to determine whether these inputs were contributing to marine food webs via assimilation by common macroinvertebrates inhabiting the inner reaches of the fjords. Terrestrially derived organic matter (TOM) had values of δ15N, δ13C and δ34S that were distinct from other carbon source pools, providing sufficient power to quantify the contribution of TOM to the benthic food web. Isotopic values among macroinvertebrates varied significantly, with consistently low values of δ15N, δ13C and δ34S for the abundant deposit feeders Echinocardium cordatum (Echinodermata) and Pectinaria australis (Annelida), indicating assimilation of TOM. High concentrations of bacterial fatty acid biomarkers in E. cordatum, and values of δ13C of these biomarkers similar to TOM (-27 to -30‰) confirmed that TOM is indirectly assimilated by these sea urchins via heterotrophic bacteria. TOM was also found to enter the infaunal food web via chemoautotrophic bacteria that live symbiotically within Solemya parkinsonii (Bivalvia). Echinocardium cordatum, Pectinaria australis and S. parkinsonii comprised up to 33.5% of the biomass of the macroinfaunal community, and thus represent strong pathways for movement of organic matter from the forested catchments into the benthic food web. This demonstration of connectivity among adjacent marine and terrestrial habitats has important implications for coastal land management, and highlights the importance of intact coastal forests to marine ecosystem function.

  14. Relationships between physical and chemical factors and aquatic macroinvertebrates in perennial streams in the arid northern mountain basin El Batinah, Oman

    Directory of Open Access Journals (Sweden)

    S. Boulaaba

    2014-08-01

    Full Text Available The relationships between physical properties, water chemistry and aquatic macroinvertebrates were investigated in riffles of four perennial streams in the arid northern Oman. Samples were collected monthly in autumn, winter and spring with a Surber net. Thirty two invertebrate taxa were recorded, most species are widely distributed, but few species with very restricted distribution were also captured. Diptera followed by Pulmonata, Coleoptera and Odonata were the most represented taxa, Trichoptera and Heteroptera were a significant component only in one station (the Fezeh, where the lowest mean water temperature (23°C was recorded. In the dry months from May to October, aquatic macroinvertebrates were completely absent. In order to summarise the community response some biotic indices were calculated. The highest diversity was observed in the Fezeh station. A seasonal gradient was also observed, with the highest diversity values in January, April, and December. The low faunal diversity was attributed to the high air and water temperature and the hydrological regime instability. A between station and a between month coinertia analysis was carried out, to analyse the response to spatial and seasonal factors. The first coinertia axis was correlated with altitude and substrate composition, while the second axis was correlated with air and water temperature. The present research emphasizes the urgency for preserving the less disturbed wadis in arid zones, because, despite their species poorness, their uniqueness in faunal composition requires special attention. The presence of few endemic species with very restricted distribution highlights the topicality and the value in investigating these areas, allowing the increase of our knowledge on biodiversity, ecology and biogeography about the benthic macroinvertebrates living in these extreme habitats.

  15. Macroinvertebrates as indicators of fish absence in naturally fishless lakes

    Science.gov (United States)

    Schilling, Emily Gaenzle; Loftin, C.S.; Huryn, Alexander D.

    2009-01-01

    1. Little is known about native communities in naturally fishless lakes in eastern North America, a region where fish stocking has led to a decline in these habitats. 2. Our study objectives were to: (i) characterise and compare macroinvertebrate communities in fishless lakes found in two biophysical regions of Maine (U.S.A.): kettle lakes in the eastern lowlands and foothills and headwater lakes in the central and western mountains; (ii) identify unique attributes of fishless lake macroinvertebrate communities compared to lakes with fish and (iii) develop a method to efficiently identify fishless lakes when thorough fish surveys are not possible. 3. We quantified macroinvertebrate community structure in the two physiographic fishless lake types (n = 8 kettle lakes; n = 8 headwater lakes) with submerged light traps and sweep nets. We also compared fishless lake macroinvertebrate communities to those in fish-containing lakes (n = 18) of similar size, location and maximum depth. We used non-metric multidimensional scaling to assess differences in community structure and t-tests for taxon-specific comparisons between lakes. 4. Few differences in macroinvertebrate communities between the two physiographic fishless lake types were apparent. Fishless and fish-containing lakes had numerous differences in macroinvertebrate community structure, abundance, taxonomic composition and species richness. Fish presence or absence was a stronger determinant of community structure in our study than differences in physical conditions relating to lake origin and physiography. 5. Communities in fishless lakes were more speciose and abundant than in fish-containing lakes, especially taxa that are large, active and free-swimming. Families differing in abundance and taxonomic composition included Notonectidae, Corixidae, Gyrinidae, Dytiscidae, Aeshnidae, Libellulidae and Chaoboridae. 6. We identified six taxa unique to fishless lakes that are robust indicators of fish absence: Graphoderus

  16. POPs data for salmonids and macroinvertebrates from Glacier Bay, Alaska - Measuring persistent organic pollutants in resident salmonids and benthic macroinvertebrates in streams near Glacier National Park, Alaska

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — A 2007 pilot study was initiated by the University of Alaska Southeast in which baseline levels of contaminants, including persistent organic pollutants (POPs) and...

  17. Impacts of Shorebirds on Macroinvertebrates in the Lower Mississippi Alluvial Valley

    Data.gov (United States)

    US Fish and Wildlife Service, Department of the Interior — Study of the impacts of migratory birds by assessing macroinvertebrate community composition, abundance and biomass associated with habitats.

  18. Disturbance frequency influences patch dynamics in stream benthic algal communities.

    Science.gov (United States)

    Ledger, Mark E; Harris, Rebecca M L; Armitage, Patrick D; Milner, Alexander M

    2008-04-01

    Disturbance is integral to the organisation of riverine ecosystems. Fluctuating low flows caused by supra-seasonal drought and water management periodically dewater habitat patches, potentially creating heterogeneity in the taxonomic composition and successional dynamics of benthic communities. The frequency of disturbance induced by low flows is contingent upon the topography of the river bed and thus varies among patches. We investigated whether the frequency of patch dewatering influenced the structure and temporal dynamics of benthic algal communities attached to the upper surfaces of stones in stream mesocosms (4 m2). In a 693-day disturbance experiment, we applied short dewatering disturbances (6 days) at high (33-day cycles) and low frequencies (99-day cycles) and compared algal assemblages with undisturbed controls at 21 endpoints. In the absence of disturbance, epilithic space was dominated by the green encrusting alga Gongrosira incrustans. However, drying disturbances consistently reduced the dominance of the green alga, and crust abundance decreased with increasing disturbance frequency, thereby opening space for a diversity of mat-forming diatoms. The response of mat diatoms to disturbance varied markedly during the experiment, from strong reductions in the abundance of loosely attached mats in mid-late 2000 to the exploitation of open space by closely adhering mats in 2001. Contrary responses were attributed to changes in the species composition of mat diatoms, which influenced the physiognomy and hence stress-resistance and resilience of the assemblage. Our results indicate that patchy dewatering of habitat patches during periods of low flow influences the successional dynamics of algae, thereby creating distinctive mosaics on the stream bed. PMID:18193289

  19. Dissolved organic carbon concentration controls benthic primary production: results from in situ chambers in north-temperate lakes

    Science.gov (United States)

    Godwin, Sean C.; Jones, Stuart E.; Weidel, Brian C.; Solomon, Christopher T.

    2014-01-01

    We evaluated several potential drivers of primary production by benthic algae (periphyton) in north-temperate lakes. We used continuous dissolved oxygen measurements from in situ benthic chambers to quantify primary production by periphyton at multiple depths across 11 lakes encompassing a broad range of dissolved organic carbon (DOC) and total phosphorous (TP) concentrations. Light-use efficiency (primary production per unit incident light) was inversely related to average light availability (% of surface light) in 7 of the 11 study lakes, indicating that benthic algal assemblages exhibit photoadaptation, likely through physiological or compositional changes. DOC alone explained 86% of the variability in log-transformed whole-lake benthic production rates. TP was not an important driver of benthic production via its effects on nutrient and light availability. This result is contrary to studies in other systems, but may be common in relatively pristine north-temperate lakes. Our simple empirical model may allow for the prediction of whole-lake benthic primary production from easily obtained measurements of DOC concentration.

  20. Benthic Foraminifera as ecological indicators for water quality on the Great Barrier Reef

    Science.gov (United States)

    Uthicke, Sven; Nobes, Kristie

    2008-07-01

    Benthic foraminifera are established indicators for Water Quality (WQ) in Florida and the Caribbean. However, nearshore coral reefs of the Great Barrier Reef (GBR) and other Pacific regions are also subjected to increased nutrient and sediment loads. Here, we investigate the use of benthic foraminifera as indicators to assess status and trends of WQ on GBR reefs. We quantified several sediment parameters and the foraminiferan assemblage composition on 20 reefs in four geographic regions of the GBR, and along a water column nutrient and turbidity gradient. Twenty-seven easily recognisable benthic foraminiferan taxa (>63 μm) were distinguished. All four geographic regions differed significantly ( p plastids ( Elphidium sp.) where highly characteristic for low light, higher nutrient conditions. Application of the FORAM index to GBR assemblage composition showed a significant increase in the value of this index with increased distance from the mainland in the Whitsunday region ( r2 = 0.75, p < 0.001), and therefore with increasing light and decreased nutrient availability. We conclude that it will be possible to apply this index to GBR and possibly other Pacific reefs after some adaptations and additional experimental work on species-specific limiting factors.

  1. Effects of Cylindrospermopsin Producing Cyanobacterium and Its Crude Extracts on a Benthic Green Alga—Competition or Allelopathy?

    OpenAIRE

    Viktória B-Béres; Gábor Vasas; Dalma Dobronoki; Sándor Gonda; Sándor Alex Nagy; István Bácsi

    2015-01-01

    Cylindrospermopsin (CYN) is a toxic secondary metabolite produced by filamentous cyanobacteria which could work as an allelopathic substance, although its ecological role in cyanobacterial-algal assemblages is mostly unclear. The competition between the CYN-producing cyanobacterium Chrysosporum (Aphanizomenon) ovalisporum, and the benthic green alga Chlorococcum sp. was investigated in mixed cultures, and the effects of CYN-containing cyanobacterial crude extract on Chlorococcum sp. were test...

  2. Littoral macroinvertebrates of acidified lakes in the Bohemian Forest

    Czech Academy of Sciences Publication Activity Database

    Ungermanová, L.; Kolaříková, K.; Stuchlík, E.; Senoo, T.; Horecký, J.; Kopáček, Jiří; Chvojka, P.; Tátosová, J.; Bitušík, P.; Fjellheim, A.

    2014-01-01

    Roč. 69, č. 9 (2014), s. 1190-1201. ISSN 0006-3088 R&D Projects: GA ČR(CZ) GA526/09/0567; GA ČR(CZ) GA206/07/1200 Grant ostatní: EC(XE) EURO-LIMPACS GOCE-CT-2003-505540 Institutional support: RVO:60077344 Keywords : lakes * macroinvertebrates * acidification * recovery * forest catchment Subject RIV: DJ - Water Pollution ; Quality Impact factor: 0.827, year: 2014

  3. New approach to phytophilous macroinvertebrates sampling in emergent littoral vegetation

    Czech Academy of Sciences Publication Activity Database

    Sychra, Jan; Adámek, Zdeněk

    Průhonice : Institute of Botany ASCR, 2006, s. 230-233. ISBN 80-86188-23-X. [International Conference on Reservoir Limnology and Water Quality /5./. Brno (CZ), 27.08.2006-31.08.2006] R&D Projects: GA ČR GD524/05/H536 Institutional research plan: CEZ:AV0Z60930519 Keywords : littoral vegetation * phytophilous macroinvertebrates * pond macrozoobenthos * sampling Subject RIV: EH - Ecology, Behaviour

  4. Stream habitat structure influences macroinvertebrate response to pesticides

    OpenAIRE

    Rasmussen, Jes; Wiberg-Larsen, Peter; Baattrup-Pedersen, Annette; Friberg, Nikolai; Kronvang, Brian

    2012-01-01

    Agricultural pesticide contamination in surface waters is increasingly threatening to impair the surface water ecosystems. Agricultural streams are furthermore often heavily maintained to optimise the transport of water away from fields. The physical habitat degradation that result from heavy stream maintenance probably introduce additional stress that may act in concert with pesticide stress. We surveyed pesticide contamination and macroinvertebrate community structure in 14 streams along a ...

  5. Macro-invertebrate decline in surface water polluted with imidacloprid

    OpenAIRE

    Tessa C Van Dijk; Van Staalduinen, Marja A.; Van der Sluijs, Jeroen P.

    2013-01-01

    Imidacloprid is one of the most widely used insecticides in the world. Its concentration in surface water exceeds the water quality norms in many parts of the Netherlands. Several studies have demonstrated harmful effects of this neonicotinoid to a wide range of non-target species. Therefore we expected that surface water pollution with imidacloprid would negatively impact aquatic ecosystems. Availability of extensive monitoring data on the abundance of aquatic macro-invertebrate species, and...

  6. Larger benthic foraminifera of the Paleogene Promina Beds (Croatia)

    Science.gov (United States)

    Cosovic, V.; Mrinjek, E.; Drobne, K.

    2012-04-01

    In order to add more information about complex origin of Promina Beds (traditionally interpreted as Paleogene molasse of Dinarides), two sections (Lišani Ostrovački and Ostrovica, Central Dalmatia, Croatia) have been studied in detail. Sampled carbonate sequences contain predominantly coralline red algae, larger benthic foraminifera and corals. Based on sedimentary textures, nummulitid (Nummulites s.str and Asterigerina sp.) test shapes and the associated skeletal components, altogether three types of the Middle Eocene (Lutetian to Bartonian) facies were recognized. The Ostrovica section is composed of alternating couples of marly limestones and marls, several decimeters thick with great lateral continuity. Two facies which vertically alternate are recognized as Nummulites - Asterigerina facies, where patchily dispersed large, robust and party reworked larger benthic foraminifera constitute 20% and small bioclasts (fomaniniferal fragments and whole tests less than 3 mm in diameters) 10% of rock volume and, Coral - Red algal facies with coral fragments of solitary and colonial taxa up to 1 cm in size constitute 5 - 40%, red algae 15 - 60% and lager benthic foraminifera up to 5% of rock volume. The textural and compositional differences among the facies suggest rhythmic exchanges of conditions that characterize shallower part of the mesophotic zone with abundant nummulithoclasts with deeper mesophotic, lime mud-dominated settings where nummulitids with the flat tests, coralline red algae and scleractinian corals are common. The scleractinian corals (comprising up to 20% of rock volume) encrusted by foraminifera (Acervulina, Haddonia and nubeculariids) or coralline red algae and foraminiferal assemblage made of orthophragminid and nummulitid tests scattered in matrix, are distributed uniformly throughout the studied Lišani Ostrovački section. In the central part of section, wavy to smooth thin (< 1 mm) crusts (laminas) alternating with encrusted corals occur. The

  7. POP bioaccumulation in macroinvertebrates of alpine freshwater systems

    Energy Technology Data Exchange (ETDEWEB)

    Bizzotto, E.C.; Villa, S. [Department of Environmental and Landscape Sciences, University of Milano-Bicocca, Piazza della Scienza 1, 20126 Milano (Italy); Vighi, M., E-mail: marco.vighi@unimib.i [Department of Environmental and Landscape Sciences, University of Milano-Bicocca, Piazza della Scienza 1, 20126 Milano (Italy)

    2009-12-15

    This study serves to investigate the uptake of POPs in the different trophic levels (scrapers, collectors, predators, shredders) of macroinvertebrate communities sampled from a glacial and a non-glacial stream in the Italian Alps. The presented results show that the contaminant concentrations in glacial communities are generally higher compared to those from non-glacial catchments, highlighting the importance of glaciers as temporary sinks of atmospherically transported pollutants. Moreover, the data also suggests that in mountain systems snow plays an important role in influencing macroinvertebrate contamination. The main chemical uptake process to the macroinvertebrates is considered to be bioconcentration from water, as similar contaminant profiles were observed between the different trophic levels. The role of biomagnification/bioaccumulation is thought to be absent or negligible. The enrichment of chemicals observed in the predators is likely to be related to their greater lipid content compared to that of other feeding groups. - Influence of POP release in glacial-fed streams, enhanced by global warming, on pristine aquatic ecosystems.

  8. POP bioaccumulation in macroinvertebrates of alpine freshwater systems

    International Nuclear Information System (INIS)

    This study serves to investigate the uptake of POPs in the different trophic levels (scrapers, collectors, predators, shredders) of macroinvertebrate communities sampled from a glacial and a non-glacial stream in the Italian Alps. The presented results show that the contaminant concentrations in glacial communities are generally higher compared to those from non-glacial catchments, highlighting the importance of glaciers as temporary sinks of atmospherically transported pollutants. Moreover, the data also suggests that in mountain systems snow plays an important role in influencing macroinvertebrate contamination. The main chemical uptake process to the macroinvertebrates is considered to be bioconcentration from water, as similar contaminant profiles were observed between the different trophic levels. The role of biomagnification/bioaccumulation is thought to be absent or negligible. The enrichment of chemicals observed in the predators is likely to be related to their greater lipid content compared to that of other feeding groups. - Influence of POP release in glacial-fed streams, enhanced by global warming, on pristine aquatic ecosystems.

  9. Using macroinvertebrates to identify biota-land cover optima at multiple scales in the Pacific Northwest, USA

    Science.gov (United States)

    Black, R.W.; Munn, M.D.; Plotnikoff, R.W.

    2004-01-01

    Macroinvertebrate assemblages and environmental variables were evaluated at 45 stream sites throughout the Puget Sound Basin, Washington, USA. Environmental variables were measured at 3 spatial scales: reach, local, and whole watershed. Macroinvertebrate distributions were related to environmental variables using canonical correspondence analysis to determine which variables and spatial scales best explained the observed community composition and to identify biota-land cover optima. The calculation of a biota-land cover optimum was a 2-step process. First, an individual taxon's optimum was estimated for a particular land cover by weighting the mean value for that land cover by the abundance of that taxon at all sites. Second, the biota-land cover optimum was determined as the point at which the greatest numbers of taxa, at their calculated optima, appeared for a particular land cover. Sampling reaches were located on streams in watersheds with varying levels of forest, agriculture, and urban/suburban land cover that represented the full range of physical conditions typically found in Puget Sound streams. At the reach scale, taxa composition was correlated with conductivity and mean velocity. At the local and whole-watershed scales, taxa composition was correlated with % forest and agricultural land cover and % forest and bedrock land cover, respectively. For all of the scales, the dominant environmental variables represented an anthropogenic gradient. There was little difference in the amount of variability explained by each spatial scale. At the local-watershed scale, a biota-land cover optimum of ???80 to 90% forest land cover was identified. The total number of taxa at their optima declined rapidly as forest land cover within the local scale declined below 80 to 90%. At the whole-watershed scale, a biota-land cover optimum of 70 to 80% forest land cover was identified. The total number of taxa at their optima declined rapidly as forest land cover within the

  10. Reef fishes of Saba Bank, Netherlands Antilles: assemblage structure across a gradient of habitat types

    OpenAIRE

    Toller, W; Debrot, A.O.; Vermeij, M.J.A.; Hoetjes, P.C.

    2010-01-01

    Saba Bank is a 2,200 km2 submerged carbonate platform in the northeastern Caribbean Sea off Saba Island, Netherlands Antilles. The presence of reef-like geomorphic features and significant shelf edge coral development on Saba Bank have led to the conclusion that it is an actively growing, though wholly submerged, coral reef atoll. However, little information exists on the composition of benthic communities or associated reef fish assemblages of Saba Bank. We selected a 40 km2 area of the bank...

  11. A Europe-wide system for assessing the quality of rivers using macroinvertebrates: the AQEM Project* and its importance for southern Europe (with special emphasis on Italy

    Directory of Open Access Journals (Sweden)

    Joanna L. KEMP

    2001-09-01

    Full Text Available The AQEM Project aims to develop a Europe-wide system for monitoring the ecological quality of rivers using macroinvertebrates, to satisfy the requirements of the EU Water Framework Directive. Three main types of anthropogenic perturbation are being investigated: morphological degradation, water (organic pollution and acidification (the last is not under investigation in Italy. The selection of reference and impaired study sites is discussed. Particular attention is paid to the problems encountered when defining reference conditions. The initial stages of the project highlighted the lack of a Europe-wide definition of river types. The future development of such a typology from the AQEM database is discussed. The standard AQEM data gathering methods are presented, from background information about sites to the microhabitat-based macroinvertebrate sampling method. The extended fieldwork methods used in Italy are described. These included the separate analysis of the invertebrate assemblages from each replicate, the recording of additional microhabitat variables for each replicate and the completion of large-scale survey techniques for each site (including RHS. The extended method was designed to enhance the important ecological information available from the dataset, particularly relevant in Italy where significant gaps exist in the taxonomic and ecological knowledge of many macroinvertebrate taxa. Preliminary and expected findings are presented, including examples of the range and habitat selection of two species of Ephemeroptera endemic to Italy, as well as data relating to the number of taxa found at a site with increasing numbers of microhabitat replicates taken. The importance of the AQEM Project not only for biomonitoring, but also for ecology, taxonomy and conservation, in Italy and for the south of Europe in general, is emphasised.

  12. Hydro-acoustic remote sensing of benthic biological communities on the shallow South East Australian continental shelf

    Science.gov (United States)

    Rattray, Alex; Ierodiaconou, Daniel; Laurenson, Laurie; Burq, Shoaib; Reston, Marcus

    2009-09-01

    Information regarding the composition and extent of benthic habitats on the South East Australian continental shelf is limited. In this habitat mapping study, multibeam echosounder (MBES) data are integrated with precisely geo-referenced video ground-truth data to quantify benthic biotic communities at Cape Nelson, Victoria, Australia. Using an automated decision tree classification approach, 5 representative biotic groups defined from video analysis were related to hydro-acoustically derived variables in the Cape Nelson survey area. Using a combination of multibeam bathymetry, backscatter and derivative products produced highest overall accuracy (87%) and kappa statistic (0.83). This study demonstrates that decision tree classifiers are capable of integrating variable data types for mapping distributions of benthic biological assemblages, which are important in maintaining biodiversity and other system services in the marine environment.

  13. Medium-term assessment of the effects of the Prestige oil spill on estuarine benthic communities in Cantabria (Northern Spain, Bay of Biscay).

    Science.gov (United States)

    Puente, A; Juanes, J A; Calderón, G; Echavarri-Erasun, B; García, A; García-Castrillo, G

    2009-04-01

    A specific monitoring program was implemented in the estuaries of Cantabria (northern Spain) in order to assess the medium-term effects (2003-2005) of the Prestige oil spill (POS) on benthic macroinvertebrate communities. A control-impact design was adopted, examining four unaffected and five oil-affected estuaries. High mortalities and significant differences in overall richness and diversity between the control and impacted estuaries were not detected. Some changes in the temporal evolution of species abundance were observed for some key species, but these could not be related to the spillage event. It was not possible to ensure that low magnitude effects had not occurred, due to the high range of natural variability of benthic communities, the confounding effects of other contamination sources and the absence of previous reference conditions. PMID:19178918

  14. Impacts of discarded plastic bags on marine assemblages and ecosystem functioning.

    Science.gov (United States)

    Green, Dannielle Senga; Boots, Bas; Blockley, David James; Rocha, Carlos; Thompson, Richard

    2015-05-01

    The accumulation of plastic debris is a global environmental problem due to its durability, persistence, and abundance. Although effects of plastic debris on individual marine organisms, particularly mammals and birds, have been extensively documented (e.g., entanglement and choking), very little is known about effects on assemblages and consequences for ecosystem functioning. In Europe, around 40% of the plastic items produced are utilized as single-use packaging, which rapidly accumulate in waste management facilities and as litter in the environment. A range of biodegradable plastics have been developed with the aspiration of reducing the persistence of litter; however, their impacts on marine assemblages or ecosystem functioning have never been evaluated. A field experiment was conducted to assess the impact of conventional and biodegradable plastic carrier bags as litter on benthic macro- and meio-faunal assemblages and biogeochemical processes (primary productivity, redox condition, organic matter content, and pore-water nutrients) on an intertidal shore near Dublin, Ireland. After 9 weeks, the presence of either type of bag created anoxic conditions within the sediment along with reduced primary productivity and organic matter and significantly lower abundances of infaunal invertebrates. This indicates that both conventional and biodegradable bags can rapidly alter marine assemblages and the ecosystem services they provide. PMID:25822754

  15. Macroalgal extracts induce bacterial assemblage shifts and sublethal tissue stress in Caribbean corals.

    Directory of Open Access Journals (Sweden)

    Kathleen M Morrow

    Full Text Available Benthic macroalgae can be abundant on present-day coral reefs, especially where rates of herbivory are low and/or dissolved nutrients are high. This study investigated the impact of macroalgal extracts on both coral-associated bacterial assemblages and sublethal stress response of corals. Crude extracts and live algal thalli from common Caribbean macroalgae were applied onto the surface of Montastraea faveolata and Porites astreoides corals on reefs in both Florida and Belize. Denaturing gradient gel electrophoresis (DGGE of 16S rRNA gene amplicons was used to examine changes in the surface mucus layer (SML bacteria in both coral species. Some of the extracts and live algae induced detectable shifts in coral-associated bacterial assemblages. However, one aqueous extract caused the bacterial assemblages to shift to an entirely new state (Lobophora variegata, whereas other organic extracts had little to no impact (e.g. Dictyota sp.. Macroalgal extracts more frequently induced sublethal stress responses in M. faveolata than in P. astreoides corals, suggesting that cellular integrity can be negatively impacted in selected corals when comparing co-occurring species. As modern reefs experience phase-shifts to a higher abundance of macroalgae with potent chemical defenses, these macroalgae are likely impacting the composition of microbial assemblages associated with corals and affecting overall reef health in unpredicted and unprecedented ways.

  16. Macroalgal extracts induce bacterial assemblage shifts and sublethal tissue stress in Caribbean corals.

    Science.gov (United States)

    Morrow, Kathleen M; Ritson-Williams, Raphael; Ross, Cliff; Liles, Mark R; Paul, Valerie J

    2012-01-01

    Benthic macroalgae can be abundant on present-day coral reefs, especially where rates of herbivory are low and/or dissolved nutrients are high. This study investigated the impact of macroalgal extracts on both coral-associated bacterial assemblages and sublethal stress response of corals. Crude extracts and live algal thalli from common Caribbean macroalgae were applied onto the surface of Montastraea faveolata and Porites astreoides corals on reefs in both Florida and Belize. Denaturing gradient gel electrophoresis (DGGE) of 16S rRNA gene amplicons was used to examine changes in the surface mucus layer (SML) bacteria in both coral species. Some of the extracts and live algae induced detectable shifts in coral-associated bacterial assemblages. However, one aqueous extract caused the bacterial assemblages to shift to an entirely new state (Lobophora variegata), whereas other organic extracts had little to no impact (e.g. Dictyota sp.). Macroalgal extracts more frequently induced sublethal stress responses in M. faveolata than in P. astreoides corals, suggesting that cellular integrity can be negatively impacted in selected corals when comparing co-occurring species. As modern reefs experience phase-shifts to a higher abundance of macroalgae with potent chemical defenses, these macroalgae are likely impacting the composition of microbial assemblages associated with corals and affecting overall reef health in unpredicted and unprecedented ways. PMID:23028648

  17. Assessment of fish assemblages in coastal lagoon habitats: Effect of sampling method

    Science.gov (United States)

    Franco, A.; Pérez-Ruzafa, A.; Drouineau, H.; Franzoi, P.; Koutrakis, E. T.; Lepage, M.; Verdiell-Cubedo, D.; Bouchoucha, M.; López-Capel, A.; Riccato, F.; Sapounidis, A.; Marcos, C.; Oliva-Paterna, F. J.; Torralva-Forero, M.; Torricelli, P.

    2012-10-01

    The structure of fish assemblages accounted for by different sampling methods (namely fyke net, seine nets, visual census) applied to vegetated and unvegetated lagoon habitats was investigated in terms of species composition, functional groups (ecological and trophic guilds), and fish size distribution. Significant differences were detected among methods, even among similar ones (seine nets). Visual census and fyke net detected more easily pelagic species, allowing the sampling of larger fish, whereas seine nets targeted more efficiently benthic-demersal species, with a dominance of 2-10 cm size classes in the fish catches. Differences were detected also among habitats, reflecting the different fish assemblages associated to vegetated and unvegetated habitats in coastal lagoons and transitional waters. However a different ability of discriminating between habitat-associated fish assemblages was recorded for the sampling methods. The different selectivity and functioning of the tested sampling methods confirm the importance of considering the targeted scale at which the research is being carried out, as well as the method that will be used to assess the ecological status of lagoon fish assemblages when choosing the most appropriate sampling method. A cross-validation of fish sampling methodologies in transitional waters is necessary to cope with the mandatory of the Water Framework Directive of standardization and comparability of monitoring methods.

  18. Influence of Water Quality on the Diversity and Distribution of Macro-Invertebrates in Hiwane Second Order Stream, Northern Ethiopia

    Directory of Open Access Journals (Sweden)

    Tsegazeabe H. Haileselasie

    2012-04-01

    Full Text Available Understanding the pattern and process related to biodiversity is a greatest challenge to the science of biological conservation. Furthermore, diversity of tropical aquatic ecosystems is severely threatened by anthropogenic activities. What is more, the continuum of most of the tropical river is interrupted by several man-made activities contributing to adverse effects which hamper provision of good quality of water. Traditionally the quality of water is assessed by physico-chemical means but recent studies have focused on the use of organisms (biota in water quality assessment for streams and lakes. Here we assessed the influence of water quality on the diversity and distribution of macroinvertebrates in Hiwane second order stream with primary objective to determine the ecological water quality status of Hiwane stream at different sampling sites using rapid field assessment screening methodology. A total of 5 sites (stream sections were selected and 4 of the sampling sites were within the city Hiwane. However, a reference site outside of the city of Hiwane was included. There were 29 taxa of benthic invertebrates belonging to ephemeroptera, odonata, plecoptera, coleoptera, trichoptera, diptera and hirudenia, among others, recorded from the river. Among these, members of Trichoptera and Ephemeroptera were predominant in density. Furthermore, species diversity is positively correlated with water quality. Since, man-made activities has lead to depletion of biota, any human activity in the drainage area which may cause changes among physico-chemical parameter could lead to a severe impact on the benthic invertebrates of Hiwane stream river. Thus, we recommend that effluent from the town should be carefully managed.

  19. Microdistribution patterns of macroinvertebrate communities upstream and downstream of organic effluents.

    Science.gov (United States)

    Alvarez-Cabria, Mario; Barquín, José; Juanes, José Antonio

    2011-01-01

    The present study analyses the distribution patterns of macroinvertebrate communities in four microhabitats (riffles, glides, leaf litter and bank roots) upstream and downstream of two waste water treatment plant (WWTP) effluents in northern Spain rivers. Macroinvertebrate communities were analysed in November 2006 by taking 5 samples from each of the microhabitats under unaffected (upstream WWTP) and affected (downstream WWTP) conditions, respectively. Water velocity, depth, substrate coarseness and hydraulic stress by means of the Froude number were also estimated at all sampling locations. Under unaffected conditions, the abundance and presence/absence of certain macroinvertebrate taxa were mainly determined by hydraulic characteristics (water velocity and Froude number) and feeding resource availability. However, neither macroinvertebrate richness nor abundance were neither significantly correlated with hydraulic stress nor substrate coarseness, although the number of macroinvertebrate taxa increased in microhabitats with high structural complexity. Macroinvertebrate abundance increased downstream of both WWTPs, while macroinvertebrate richness was not adversely affected by the organic enrichment of water. The structure and composition of macroinvertebrate communities occurring in riffles was similar under unaffected and affected conditions, while communities from leaf litter and submerged bank roots showed important changes above and below the WWTPs, indicating that they are probably the most appropriate communities for water quality assessment. PMID:21168894

  20. Comparing the performance of different stream classification systems using aquatic macroinvertebrates

    OpenAIRE

    Márlon de Castro Vasconcelos; Adriano Sanches Melo; Albano Schwarzbold

    2013-01-01

    AIM: We evaluated five stream classification systems observing: 1) differences in richness, abundance and macroinvertebrates communities among stream classes within classification systems; and 2) whether classification systems present better performance using macroinvertebrates. Additionally, we evaluated the effects of taxonomic resolution and data type (abundance and presence) on results. METHODS: Five stream classification systems were used, two based on hydroregions, one based on ecoregio...

  1. Benthic community of the Savannah River below a peaking hydropower station

    Science.gov (United States)

    Hudson, Patrick L.; Nichols, S. Jerrine

    1986-01-01

    The Savannah River below Hartwell Dam, on the South Carolina-Georgia border, contains at least 206 benthic invertebrate taxa, even though this tailwater undergoes substantial daily fluctuations in water flow, temperature, and dissolved oxygen. Oligochaetes, chironomids, and amphipods dominate the community immediately below the dam. Farther downstream, larger organisms (i.e., Ephemeroptera, Trichoptera, etc.) dominate the benthic community. The high diversity of this system is primarily attributed to the intensive effort we expended to identify invertebrates to species level. We conclude that tailwaters associated with peaking hydropower stations may in fact have the diverse community assemblages found in natural streams and that this has not been recognized by other investigators because the bulk of the fauna is made up of small forms that are easily overlooked. Comparisons of tailwater fauna communities with those in control areas should be limited to rivers of similar size.

  2. Benthic Trophic Interactions in an Antarctic Shallow Water Ecosystem Affected by Recent Glacier Retreat.

    Directory of Open Access Journals (Sweden)

    Francesca Pasotti

    Full Text Available The western Antarctic Peninsula is experiencing strong environmental changes as a consequence of ongoing regional warming. Glaciers in the area are retreating rapidly and increased sediment-laden meltwater runoff threatens the benthic biodiversity at shallow depths. We identified three sites with a distinct glacier-retreat related history and different levels of glacial influence in the inner part of Potter Cove (King George Island, South Shetland Islands, a fjord-like embayment impacted since the 1950s by a tidewater glacier retreat. We compared the soft sediment meio- and macrofauna isotopic niche widths (δ13C and δ15N stable isotope analysis at the three sites to investigate possible glacier retreat-related influences on benthic trophic interactions. The isotopic niches were locally shaped by the different degrees of glacier retreat-related disturbance within the Cove. Wider isotopic niche widths were found at the site that has become ice-free most recently, and narrower niches at the older ice-free sites. At an intermediate state of glacier retreat-related disturbance (e.g. via ice-growler scouring species with different strategies could settle. The site at the earliest stage of post-retreat development was characterized by an assemblage with lower trophic redundancy. Generally, the isotopic niche widths increased with increasing size spectra of organisms within the community, excepting the youngest assemblage, where the pioneer colonizer meiofauna size class displayed the highest isotopic niche width. Meiofauna at all sites generally occupied positions in the isotopic space that suggested a detrital-pool food source and/or the presence of predatory taxa. In general ice scour and glacial impact appeared to play a two-fold role within the Cove: i either stimulating trophic diversity by allowing continuous re-colonization of meiofaunal species or, ii over time driving the benthic assemblages into a more compact trophic structure with

  3. Living benthic foraminifera as an environmental proxy in coastal ecosystems: A case study from the Aegean Sea (Greece, NE Mediterranean)

    Science.gov (United States)

    Koukousioura, Olga; Dimiza, Margarita D.; Triantaphyllou, Maria V.; Hallock, Pamela

    2011-12-01

    The species composition of the epiphytic benthic foraminiferal fauna was compared at two coastal locations in the Aegean Sea. Samples were collected during August 2001 and July 2003 along the southeastern coast of Andros Island at Korthi Gulf, where there are minimal anthropogenic activities, and at Kastro Gulf, with substantial anthropogenic influence. This study represents the first application of the FORAM Index (FI), which is a single-metric index for water quality originally developed for western Atlantic reef foraminiferal assemblages, to Mediterranean assemblages. Multivariate analyses distinguished three clusters of sample sites representing three foraminiferal assemblages. Samples dominated by the mixotrophic species, A. lobifera, were collected primarily from sites along the northern coasts of both gulfs. Characteristics of this assemblage, including relatively high dominance (D = 0.27-0.51), lower Shannon-Wiener diversity (H' = 1.3-2.1) and high FI (6.6-8.2), all reflect oligotrophic environmental conditions typical of pristine waters of the Aegean Sea. A. lobifera was typically the most common species in the second assemblage, though relative abundances of heterotrophic taxa were higher, resulting in somewhat higher diversity (H' = 1.6-2.4) and lower dominance (D = 0.14-0.36). These indices, as well as the FI range of 3.5-7.0 indicated somewhat more prevalent organic carbon resources but still relatively high water quality. This assemblage was found along the southern coast of Korthi Gulf and at more interior sites in northern Kastro Gulf. The third assemblage was dominated by smaller heterotrophic species, including notable proportions of the stress-tolerant taxa Ammonia spp. and Elphidium spp., and had few or no A. lobifera. Diversity (H' = 1.4-2.0) and dominance (D = 0.22-0.47) indices were similar to those for the first assemblage, but FI values were much lower (2.0-3.4). Samples characterized by this assemblage were collected only from the southern

  4. Setting limits: The development and use of factor-ceiling distributions for an urban assessment using macroinvertebrates

    Science.gov (United States)

    Carter, J.L.; Fend, S.V.

    2005-01-01

    Lotic habitats in urban settings are often more modified than in other anthropogenically influenced areas. The extent, degree, and permanency of these modifications compromise the use of traditional reference-based study designs to evaluate the level of lotic impairment and establish restoration goals. Directly relating biological responses to the combined effects of urbanization is further complicated by the nonlinear response often observed in common metrics (e.g., Ephemeroptera, Plecoptera, and Trichoptera [EPT] species richness) to measures of human influence (e.g., percentage urban land cover). A characteristic polygonal biological response often arises from the presence of a generalized limiting factor (i.e., urban land use) plus the influence of multiple additional stressors that are nonuniformly distributed throughout the urban environment. Benthic macroinvertebrates, on-site physical habitat and chemistry, and geographical information systems-derived land cover data for 85 sites were collected within the 1,600-km2 Santa Clara Valley (SCV), California urban area. A biological indicator value was derived from EPT richness and percentage EPT. Partitioned regression was used to define reference conditions and estimate the degree of site impairment. We propose that an upper-boundary condition (factor-ceiling) modeled by partitioned regression using ordinary least squares represents an attainable upper limit for biological condition in the SCV area. Indicator values greater than the factor-ceiling, which is monotonically related to existing land use, are considered representative of reference conditions under the current habitat conditions imposed by existing land cover and land use.

  5. Two-Year Comparison of a Stream Macroinvertebrate Functional Group Bioassessment Protocol for the Republic of Palau Archipelago

    Science.gov (United States)

    Olesen, A. A.; Benbow, M. E.; Holm, T.; Burky, A. J.

    2005-05-01

    Macroinvertebrate functional feeding group data was collected in 2003 and 2004 to develop a rapid bioassessment protocol for Palauan streams. One reference stream, Ngardmau, was selected to test functional group ratios and associated ecosystem attributes against streams of variable impact. In both years qualitative samples were collected using 30s dip net samples in pool habitats and benthic scouring methods in cascades with additional quantitative cascade collections for sampling technique comparisons in 2004. In the reference stream riffle habitat, filtering-gatherers dominated the community (89.92% in 2003 and 47.37% in 2004) compared to all other functional groups. Among the impacted streams, riffle functional group composition was variable compared to the reference stream. In reference pool habitats, gathering-collectors and scrapers dominated in 2003 and 2004, respectively. Scrapers dominated pool habitats of impacted streams in 2004, with some functional groups missing. Changes in ecosystem attributes followed functional group variability depending on degree of impact. Functional group ratios indicated channel stability ratio ([filtering-collectors + scrapers]/[shredders + gathering-collectors]) was lowered with increasing impact, suggesting food and/or habitat quality for filtering-collectors was degraded in riffle habitats in 2003 with no trends in 2004. By this protocol streams were determined to be degraded in 2004 relative to 2003.

  6. Boron in Pariette Wetland Sediments, Aquatic Vegetation & Benthic Organisms

    Science.gov (United States)

    Vasudeva, P.; Jones, C. P.; Powelson, D.; Jacobson, A. R.

    2015-12-01

    The Pariette Wetlands are comprised of 20 ponds located in Utah's Uintah Basin. Boron concentration in the Pariette Wetlands have been observed to exceed the total maximum daily limit of 750 µg L-1. Considering water flow in and out of the wetlands, boron is accumulating within the wetlands where it is sorbed to sediments and bioconcentrated by wetland plant and macro invertebrates. Since boron is an avian teratogen, an estimate of boron ingestion exposure is warranted. Samples from 3 of the 23 Pariette Wetland ponds with one pond near the inlet, one near the outlet, and one in the middle were collected. Five sampling points were designated along a 100 m transect of each pond. At each sampling point duplicate (or triplicate) samples of water, sediments, benthic organisms and wetland vegetation were collected. The sediments were collected with a KB-corer and divided at depths of 0-2 cm, 2-7 cm, and 7+ cm from the sediment surface. Sample splits were sent to the USU Bug lab for identification of invertebrate species. Whenever this transect was not intercepting vegetation, 2-3 additional sample sites were identified at the pond within stands of representative vegetation where bird nests are located. The plant parts used for boron analyses will include seeds, shoot and roots of vascular plants, as well as algae or duckweeds skimmed from the surface. Samples were processed within 2 days of collection. Water samples filtered through a 0.45 μ membrane filter were analyzed for DOC, pH and ECe. The dried and washed vegetation samples were ground and stored. The benthic organisms and macro invertebrates were netted at the water surface. The dried samples were weighed, ground and stored. Samples were weighed, oven dried and reweighed. For plant and macro-invertebrate samples, a nitric and hydrogen peroxide digestion procedure is used to dissolve environmentally available elements. The Hot Water extraction and DTPA-Sorbitol extraction were compared to estimate wetland plant

  7. Low level off-road vehicle (ORV) traffic negatively impacts macroinvertebrate assemblages at sandy beaches in south-western Australia

    Science.gov (United States)

    Davies, Rebecca; Speldewinde, Peter C.; Stewart, Barbara A.

    2016-01-01

    Off-road vehicle use is arguably one of the most environmentally damaging human activities undertaken on sandy beaches worldwide. Existing studies focused on areas of high traffic volumes have demonstrated significantly lower abundance, diversity and species richness of fauna in zones where traffic is concentrated. The impact of lower traffic volumes is unknown. This study aimed to investigate the impacts of relatively low-level vehicle traffic on sandy beach fauna by sampling invertebrate communities at eight beaches located in south-western Australia. We found that even low-level vehicle traffic negatively impacts the physical beach environment, and consequently, the ability of many species to survive in this habitat in the face of this disturbance. Compaction, rutting and displacement of the sand matrix were observed over a large area, resulting in significant decreases in species diversity and density, and measurable shifts in community structure on beaches that experienced off-road vehicle traffic. Communities at impact sites did not display seasonal recovery as traffic was not significantly different between seasons. Given a choice between either reducing traffic volumes, or excluding ORV traffic from beaches, our results suggest that the latter would be more appropriate when the retention of ecological integrity is the objective. PMID:27121212

  8. Macroinvertebrate diversity loss in urban streams from tropical forests.

    Science.gov (United States)

    Docile, Tatiana N; Figueiró, Ronaldo; Portela, Clayton; Nessimian, Jorge L

    2016-04-01

    The increase of human activities in recent years has significantly interfered and affected aquatic ecosystems. In this present study, we investigate the effects of urbanization in the community structure of aquatic macroinvertebrates from Atlantic Forest streams. The sampling was conducted in the mountainous region of the State of Rio de Janeiro, Brazil in 10 urban and 10 preserved streams during the dry season (August-September) of 2012. The streams were characterized for its environmental integrity conditions and physico-chemical properties of water. The macroinvertebrates were sampled on rocky substrates with a kicknet. A total of 5370 individuals were collected from all streams and were distributed among Ephemeroptera, Odonata, Plecoptera, Hemiptera, Megaloptera, Coleoptera, Trichoptera, Lepidoptera, and Diptera. In urban sites, all those orders were found, except Megaloptera, while only Mollusca was not found in preserved streams. We performed a non-metric multidimensional scaling (NMDS) analysis that separated two groups distributed among sites in urban communities and another group outside this area. The dominance was significantly higher at urban sites, while the α diversity and equitability were greater in preserved sites. A canonical correspondence analysis (CCA) was also performed, indicating that most taxa associated with high values of the Habitat Integrity Index (HII) and a few genus of the order Diptera with the high values of ammonia, total nitrogen, associated to streams in urban sites. Urban and preserved streams differ by physical-chemical variables and aquatic macroinvertebrates. In urban streams, there is most dominance, while α diversity and equitability are higher in preserved streams. PMID:27003402

  9. Benthic biodiversity patterns in Ria de Aveiro, Western Portugal: Environmental-biological relationships

    Science.gov (United States)

    Rodrigues, Ana Maria; Quintino, Victor; Sampaio, Leandro; Freitas, Rosa; Neves, Ramiro

    2011-12-01

    This study characterizes the macrobenthic gradients in Ria de Aveiro, Western Portugal. Ria de Aveiro is the meeting place of a number of river basins, resulting in a transition system of complex geometry, with channels running parallel to the coast line, north and south of the entrance, but also inland, creating an intricate system of navigation channels, islands and intertidal sand and mudflats. This renders unique characteristics to this system within the framework of transitional waters. The study was based on the analysis of samples from 248 sites, covering the full salinity gradient and the entire channel system. A total of 120 taxa in more than 76,350 specimens were identified. The most abundant and frequent taxa were all annelids, namely Alkmaria romijni, Streblospio shrubsolii, Tharyx sp., Tubificoides benedii, Nereis diversicolor, Capitella sp., Pygospio elegans, Polydora ligni and an unidentified oligochaete. The spatial distribution of the fauna was found to be mainly related to hydrodynamics and the salinity gradient, whereas sediment grain-size characteristics were much less important. Shear stress, flux, current velocity, salinity and sediment redox potential were the environmental variables which best related to the biological data. Benthic assemblages succeed from the euhaline pole, at the entrance, to the limnetic poles, located in the inner parts of the channels. In this succession, mean abundance increased from the outward to the inward assemblages but species richness and diversity were higher in intermediate assemblages. These descriptors decrease abruptly in the limnetic areas. Using the M-AMBI index, the ecological quality of Ria de Aveiro revealed moderate, poor and bad status. However, the ecological status spatial trend closely followed the benthic assemblages succession, their species richness and diversity, indicating the need for proper reference conditions and inter-calibration exercises in the transition waters before final

  10. The human impact on benthic community structure and dynamics of different ecosystems from Lunca Mureșului Nature Park (West of Romania

    Directory of Open Access Journals (Sweden)

    Andreea A. Marin

    2011-01-01

    Full Text Available The anthropic impact, which takes various forms, changes the water quality parameters anddisturb the living environment of benthic macroinvertebrates. The present study aims to track the waypollution sources influence the macrozoobenthic community. Collecting quantitative samples, at differentseasons, from Mureș River and Cărămidăriei Lake, within the area of Lunca Mureșului Nature Park beforeand after each major pollution source, shows the way pollution affects, both qualitatively andquantitatively, the community of benthic invertebrates. 9 groups of benthic invertebrates were identified,their density, abundance and frequency undergoing changes from one station to another and from oneseason to another. When the river flows through the park, the benthic community reflects strong waterquality degradation of Mureș River. The river, naturally flowing on a long distance allows, through theself-purification process, an improvement in water quality emphasized by the occurrence of somesensitive groups to pollution which disappear completely once the tributary stream Mureșelul and othernon-purified waters from the town of Pecica flow into the river. The seasonal dynamics of dominantgroups (Oligochaeta, Diptera-Chironomidae suggests a similarity, recording high values within theautumn-winter time interval.

  11. Spatial segregation in eastern North Pacific skate assemblages.

    Science.gov (United States)

    Bizzarro, Joseph J; Broms, Kristin M; Logsdon, Miles G; Ebert, David A; Yoklavich, Mary M; Kuhnz, Linda A; Summers, Adam P

    2014-01-01

    Skates (Rajiformes: Rajoidei) are common mesopredators in marine benthic communities. The spatial associations of individual species and the structure of assemblages are of considerable importance for effective monitoring and management of exploited skate populations. This study investigated the spatial associations of eastern North Pacific (ENP) skates in continental shelf and upper continental slope waters of two regions: central California and the western Gulf of Alaska. Long-term survey data were analyzed using GIS/spatial analysis techniques and regression models to determine distribution (by depth, temperature, and latitude/longitude) and relative abundance of the dominant species in each region. Submersible video data were incorporated for California to facilitate habitat association analysis. We addressed three main questions: 1) Are there regions of differential importance to skates?, 2) Are ENP skate assemblages spatially segregated?, and 3) When skates co-occur, do they differ in size? Skate populations were highly clustered in both regions, on scales of 10s of kilometers; however, high-density regions (i.e., hot spots) were segregated among species. Skate densities and frequencies of occurrence were substantially lower in Alaska as compared to California. Although skates are generally found on soft sediment habitats, Raja rhina exhibited the strongest association with mixed substrates, and R. stellulata catches were greatest on rocky reefs. Size segregation was evident in regions where species overlapped substantially in geographic and depth distribution (e.g., R. rhina and Bathyraja kincaidii off California; B. aleutica and B. interrupta in the Gulf of Alaska). Spatial niche differentiation in skates appears to be more pronounced than previously reported. PMID:25329312

  12. Spatial segregation in eastern North Pacific skate assemblages.

    Directory of Open Access Journals (Sweden)

    Joseph J Bizzarro

    Full Text Available Skates (Rajiformes: Rajoidei are common mesopredators in marine benthic communities. The spatial associations of individual species and the structure of assemblages are of considerable importance for effective monitoring and management of exploited skate populations. This study investigated the spatial associations of eastern North Pacific (ENP skates in continental shelf and upper continental slope waters of two regions: central California and the western Gulf of Alaska. Long-term survey data were analyzed using GIS/spatial analysis techniques and regression models to determine distribution (by depth, temperature, and latitude/longitude and relative abundance of the dominant species in each region. Submersible video data were incorporated for California to facilitate habitat association analysis. We addressed three main questions: 1 Are there regions of differential importance to skates?, 2 Are ENP skate assemblages spatially segregated?, and 3 When skates co-occur, do they differ in size? Skate populations were highly clustered in both regions, on scales of 10s of kilometers; however, high-density regions (i.e., hot spots were segregated among species. Skate densities and frequencies of occurrence were substantially lower in Alaska as compared to California. Although skates are generally found on soft sediment habitats, Raja rhina exhibited the strongest association with mixed substrates, and R. stellulata catches were greatest on rocky reefs. Size segregation was evident in regions where species overlapped substantially in geographic and depth distribution (e.g., R. rhina and Bathyraja kincaidii off California; B. aleutica and B. interrupta in the Gulf of Alaska. Spatial niche differentiation in skates appears to be more pronounced than previously reported.

  13. Stream habitat structure influences macroinvertebrate response to pesticides

    DEFF Research Database (Denmark)

    Rasmussen, Jes; Wiberg-Larsen, Peter; Baattrup-Pedersen, Annette;

    2012-01-01

    Agricultural pesticide contamination in surface waters is increasingly threatening to impair the surface water ecosystems. Agricultural streams are furthermore often heavily maintained to optimise the transport of water away from fields. The physical habitat degradation that result from heavy...... the effects of pesticides between sites with degraded and more undisturbed physical properties. The effect of pesticides on macroinvertebrate communities (measured as the relative abundance of SPEcies At Risk) was increased at stream sites with degraded physical habitats primarily due to the absence...... of species with specific preferences for habitats with hard substrate. Our findings highlight the importance of considering physical habitat degradation in the assessment and mitigation of risk in agricultural streams....

  14. An unusually large phytoplankton spring bloom drives rapid changes in benthic diversity and ecosystem function

    Science.gov (United States)

    Zhang, Qingtian; Warwick, Richard M.; McNeill, Caroline L.; Widdicombe, Claire E.; Sheehan, Aaron; Widdicombe, Stephen

    2015-09-01

    In 2012, the Western English Channel experienced an unusually large and long-lived phytoplankton spring bloom. When compared with data from the past 20 years, average phytoplankton biomass at Station L4 (part of the Western Channel Observatory) was approximately 3× greater and lasted 50% longer than any previous year. Regular (mostly weekly) box core samples were collected from this site before, during and after the bloom to determine its impact on macrofaunal abundance, diversity, biomass, community structure and function. The spring bloom of 2012 was shown to support a large and rapid response in the majority of benthic taxa and functional groups. However, key differences in the precise nature of this response, as well as in its timing, was observed between different macrofauna feeding groups. Deposit feeders responded almost instantly at the start of the bloom, primarily thorough an increase in abundance. Suspension feeders and opportunistic/predatory/carnivorous taxa responded slightly more slowly and primarily with an increase in biomass. At the end of the bloom a rapid decline in macrobenthic abundance, diversity and biomass closely followed the decline in phytoplankton biomass. With suspension feeders showing evidence of this decline a few weeks before deposit feeders, it was concluded that this collapse in benthic communities was driven primarily by food availability and competition. However, it is possible that environmental hypoxia and the presence of toxic benthic cyanobacteria could also have contributed to this decline. This study shows evidence for strong benthic-pelagic coupling at L4; a shallow (50 m), coastal, fine-sand habitat. It also demonstrates that in such habitats, it is not just planktonic organisms that demonstrate clear community phenology. Different functional groups within the benthic assemblage will respond to the spring bloom in specific manner, with implications for key ecosystem functions and processes, such as secondary production

  15. Effects of a Kentucky flood-control reservoir on macroinvertebrates in the tailwater

    Science.gov (United States)

    Novotny, J.F.

    1985-01-01

    The effects of a flood-control reservoir on downstream macroinvertebrates were assessed by comparing the tailwater community with that of a natural stream. Samples were collected 1.6 and 21.1 km below Barren River Lake dam in 1979, 1980, and 1981 and in a reservoir tributary in 1980 and 1981. An indication of environmental stress in the macroinvertebrate community was observed at both tailwater stations, whereas macroinvertebrates in the natural tributary stream had the characteristics commonly associated with a ‘healthy’ community. Densities of macroinvertebrates in tailwaters were highest during periods of low-stable flows and lowest during fluctuating and high-stable flows. Changes in temperature cycles and water quality were also considered factors in reducing macroinvertebrate abundance in the tailwater. Dominant macroinvertebrate taxa in tailwaters were primarily small organisms with a high tolerance for dynamic living conditions. Of these, aquatic Diptera, Oligochaeta, Caenis, Cheumatopsyche, and Planariidae were most common. The effects of reservoir discharge were most evident near the dam, where macroinvertebrate densities were relatively high and taxonomic diversity was low. Downstream, the impact of the reservoir was moderated, but recovery was judged incomplete.

  16. When is the best time to sample aquatic macroinvertebrates in ponds for biodiversity assessment?

    Science.gov (United States)

    Hill, M J; Sayer, C D; Wood, P J

    2016-03-01

    Ponds are sites of high biodiversity and conservation value, yet there is little or no statutory monitoring of them across most of Europe. There are clear and standardised protocols for sampling aquatic macroinvertebrate communities in ponds, but the most suitable time(s) to undertake the survey(s) remains poorly specified. This paper examined the aquatic macroinvertebrate communities from 95 ponds within different land use types over three seasons (spring, summer and autumn) to determine the most appropriate time to undertake sampling to characterise biodiversity. The combined samples from all three seasons provided the most comprehensive record of the aquatic macroinvertebrate taxa recorded within ponds (alpha and gamma diversity). Samples collected during the autumn survey yielded significantly greater macroinvertebrate richness (76% of the total diversity) than either spring or summer surveys. Macroinvertebrate diversity was greatest during autumn in meadow and agricultural ponds, but taxon richness among forest and urban ponds did not differ significantly temporally. The autumn survey provided the highest measures of richness for Coleoptera, Hemiptera and Odonata. However, richness of the aquatic insect order Trichoptera was highest in spring and lowest in autumn. The results illustrate that multiple surveys, covering more than one season, provide the most comprehensive representation of macroinvertebrate biodiversity. When sampling can only be undertaken on one occasion, the most appropriate time to undertake surveys to characterise the macroinvertebrate community biodiversity is during autumn, although this may need to be modified if other floral and faunal groups need to be incorporated into the sampling programme. PMID:26920128

  17. Patterns of Assemblage Structure Indicate a Broader Conservation Potential of Focal Amphibians for Pond Management.

    Science.gov (United States)

    Soomets, Elin; Rannap, Riinu; Lõhmus, Asko

    2016-01-01

    Small freshwater ponds host diverse and vulnerable biotic assemblages but relatively few conspicuous, specially protected taxa. In Europe, the amphibians Triturus cristatus and Pelobates fuscus are among a few species whose populations have been successfully restored using pond restoration and management activities at the landscape scale. In this study, we explored whether the ponds constructed for those two target species have wider conservation significance, particularly for other species of conservation concern. We recorded the occurrence of amphibians and selected aquatic macro-invertebrates (dragonflies; damselflies; diving beetles; water scavenger beetles) in 66 ponds specially constructed for amphibians (up to 8 years post construction) and, for comparison, in 100 man-made ponds (created by local people for cattle or garden watering, peat excavation, etc.) and 65 natural ponds in Estonia. We analysed nestedness of the species assemblages and its dependence on the environment, and described the co-occurrence patterns between the target amphibians and other aquatic species. The assemblages in all ponds were significantly nested, but the environmental determinants of nestedness and co-occurrence of particular species differed among pond types. Constructed ponds were most species-rich irrespective of the presence of the target species; however, T. cristatus was frequent in those ponds and rare elsewhere, and it showed nested patterns in every type of pond. We thus conclude that pond construction for the protected amphibians can serve broader habitat conservation aims in the short term. However, the heterogeneity and inconsistent presence of species of conservation concern observed in other types of ponds implies that long-term perspectives on pond management require more explicit consideration of different habitat and biodiversity values. We also highlight nestedness analysis as a tool that can be used for the practical task of selecting focal species for

  18. Marine Invertebrate assemblages in southern California

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — This is a point file of invertebrate site clusters calculated from benthic trawls completed by the Southern California Coastal Water Research Project (SCCWRP). Data...

  19. Nearshore marine fish assemblages in southern California

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — Fish benthic trawls were completed by the Southern California Coastal Water Research Project (SCCWRP). Data from 425 fisheries independent trawls ranging from 2-215...

  20. Mechanisms of temporary adhesion in benthic animals

    NARCIS (Netherlands)

    Dodou, D.; Breedveld, P.; Winter, J.C.F.; Dankelman, J.; Leeuwen, van J.L.

    2011-01-01

    Adhesive systems are ubiquitous in benthic animals and play a key role in diverse functions such as locomotion, food capture, mating, burrow building, and defence. For benthic animals that release adhesives, surface and material properties and external morphology have received little attention compa

  1. Modern diatom, cladocera, chironomid, and chrysophyte cyst assemblages as quantitative indicators for the reconstruction of past environmental conditions in the Alps. I. Climate

    OpenAIRE

    Lotter, A. F.; H. J. B. Birks; Hofmann, W.; Marchetto, A.

    1997-01-01

    Diatom, chrysophyte cyst, benthic cladocera, planktonic cladocera, and chironomid assemblages were studied in the surface sediments of 68 small lakes along an altitudinal gradient from 300 to 2350 m in Switzerland. In addition, 43 environmental variables relating to the physical limnology, geography, catchment characteristics, climate, and water chemistry were recorded or measured for each lake. The explanatory power of each of these predictor variables for the different biological data-sets ...

  2. Marine Microphytobenthic Assemblage Shift along a Natural Shallow-Water CO2 Gradient Subjected to Multiple Environmental Stressors

    Directory of Open Access Journals (Sweden)

    Vivienne R. Johnson

    2015-12-01

    Full Text Available Predicting the effects of anthropogenic CO2 emissions on coastal ecosystems requires an understanding of the responses of algae, since these are a vital functional component of shallow-water habitats. We investigated microphytobenthic assemblages on rock and sandy habitats along a shallow subtidal pCO2 gradient near volcanic seeps in the Mediterranean Sea. Field studies of natural pCO2 gradients help us understand the likely effects of ocean acidification because entire communities are subjected to a realistic suite of environmental stressors such as over-fishing and coastal pollution. Temperature, total alkalinity, salinity, light levels and sediment properties were similar at our study sites. On sand and on rock, benthic diatom abundance and the photosynthetic standing crop of biofilms increased significantly with increasing pCO2. There were also marked shifts in diatom community composition as pCO2 levels increased. Cyanobacterial abundance was only elevated at extremely high levels of pCO2 (>1400 μatm. This is the first demonstration of the tolerance of natural marine benthic microalgae assemblages to elevated CO2 in an ecosystem subjected to multiple environmental stressors. Our observations indicate that Mediterranean coastal systems will alter as pCO2 levels continue to rise, with increased photosynthetic standing crop and taxonomic shifts in microalgal assemblages.

  3. Patterns of Macroinvertebrate and Fish Diversity in Freshwater Sulphide Springs

    Directory of Open Access Journals (Sweden)

    Ryan Greenway

    2014-09-01

    Full Text Available Extreme environments are characterised by the presence of physicochemical stressors and provide unique study systems to address problems in evolutionary ecology research. Sulphide springs provide an example of extreme freshwater environments; because hydrogen sulphide’s adverse physiological effects induce mortality in metazoans even at micromolar concentrations. Sulphide springs occur worldwide, but while microbial communities in sulphide springs have received broad attention, little is known about macroinvertebrates and fish inhabiting these toxic environments. We reviewed qualitative occurrence records of sulphide spring faunas on a global scale and present a quantitative case study comparing diversity patterns in sulphidic and adjacent non-sulphidic habitats across replicated river drainages in Southern Mexico. While detailed studies in most regions of the world remain scarce, available data suggests that sulphide spring faunas are characterised by low species richness. Dipterans (among macroinvertebrates and cyprinodontiforms (among fishes appear to dominate the communities in these habitats. At least in fish, there is evidence for the presence of highly endemic species and populations exclusively inhabiting sulphide springs. We provide a detailed discussion of traits that might predispose certain taxonomic groups to colonize sulphide springs, how colonizers subsequently adapt to cope with sulphide toxicity, and how adaptation may be linked to speciation processes.

  4. Stream habitat structure influences macroinvertebrate response to pesticides

    International Nuclear Information System (INIS)

    Agricultural pesticides continue to impair surface water ecosystems, although there are few assessments of interactions with other modifications such as fine sediment and physical alteration for flood drainage. We, therefore, surveyed pesticide contamination and macroinvertebrates in 14 streams along a gradient of expected pesticide exposure using a paired-reach approach to differentiate effects between physically modified and less modified sites. Apparent pesticides effects on the relative abundance of SPEcies At Risk (SPEAR) were increased at sites with degraded habitats primarily due to the absence of species with specific preferences for hard substrates. Our findings highlight the importance of physical habitat degradation in the assessment and mitigation of pesticide risk in agricultural streams. - Highlights: ► %SPEAR abundance significantly decreased with increasing TU (D. magna). ► %SPEAR abundance was significantly lower when soft sediment was dominant. ► Species specific habitat preferences influenced the total effect of pesticides. ► This study has strong implications for future stream management and risk assessment. - Ecological impacts of pesticides on stream macroinvertebrates are influenced by the heterogeneity and physical structure of micro-habitats.

  5. Comparison of aquatic macroinvertebrate samples collected using different field methods

    Science.gov (United States)

    Lenz, Bernard N.; Miller, Michael A.

    1996-01-01

    Government agencies, academic institutions, and volunteer monitoring groups in the State of Wisconsin collect aquatic macroinvertebrate data to assess water quality. Sampling methods differ among agencies, reflecting the differences in the sampling objectives of each agency. Lack of infor- mation about data comparability impedes data shar- ing among agencies, which can result in duplicated sampling efforts or the underutilization of avail- able information. To address these concerns, com- parisons were made of macroinvertebrate samples collected from wadeable streams in Wisconsin by personnel from the U.S. Geological Survey- National Water Quality Assessment Program (USGS-NAWQA), the Wisconsin Department of Natural Resources (WDNR), the U.S. Department of Agriculture-Forest Service (USDA-FS), and volunteers from the Water Action Volunteer-Water Quality Monitoring Program (WAV). This project was part of the Intergovernmental Task Force on Monitoring Water Quality (ITFM) Wisconsin Water Resources Coordination Project. The numbers, types, and environmental tolerances of the organ- isms collected were analyzed to determine if the four different field methods that were used by the different agencies and volunteer groups provide comparable results. Additionally, this study com- pared the results of samples taken from different locations and habitats within the same streams.

  6. Distribution of benthic macroinvertebrates in relationship to plant roots, sediment type and spatial scale in fishponds and slow streams

    Czech Academy of Sciences Publication Activity Database

    Ságová-Marečková, Markéta

    2002-01-01

    Roč. 156, č. 1 (2002), s. 63-81. ISSN 0003-9136 Grant ostatní: GA the Fond rozvoje vysokých škol(XX) 0463/98; GA the Fond rozvoje vysokých škol(XX) 148/99; GA-(CZ) no.94035 Institutional research plan: CEZ:AV0Z5020903 Keywords : sediment quality * environmental factors * biotic factors Subject RIV: EE - Microbiology, Virology Impact factor: 1.195, year: 2002

  7. Occurrence of polycyclic aromatic hydrocarbons below coal-tar-sealed parking lots and effects on stream benthic macroinvertebrate communities

    Energy Technology Data Exchange (ETDEWEB)

    Scoggins, M.; McClintock, N.L.; Gosselink, L.; Bryer, P. [City Austin, Austin, TX (United States)

    2007-12-15

    Parking-lot pavement sealants recently have been recognized as a major source of polycyclic aromatic hydrocarbons (PAHs) in urban stream sediments in Austin, Texas. Laboratory and field studies have shown that PAHs in sediments can be toxic to aquatic organisms and can degrade aquatic communities. After identifying increases in concentrations of PAHs in sediments below seal-coated parking lots, we investigated whether the increases had significant effects on stream biota in 5 Austin streams. We sampled sediment chemistry and biological communities above and below the point at which stormwater runoff from the parking lots discharged into the streams, thus providing 5 upstream reference sites and 5 downstream treatment sites. Differences between upstream and downstream concentrations of total PAH ranged from 3.9 to 32 mg/kg. Analysis of the species occurrence data from pool and riffle habitats indicated a significant decrease in community health at the downstream sites, including decreases in richness, intolerant taxa, Diptera taxa, and density. In pool sediments, Chironomidae density was negatively correlated with PAH concentrations, whereas Oligochaeta density responded positively to PAH concentrations. In general, pool taxa responded more strongly than riffle taxa to PAHs, but riffle taxa responded more broadly than pool taxa. Increases in PAH sediment-toxicity units between upstream and downstream sites explained decreases in taxon richness and density in pools between upstream and downstream sites.

  8. Ecology and bioindicator potential of benthic macroinvertebrates in a Mediterranean salt wedge estuary: the Ebro River case

    OpenAIRE

    Nebra Costas, Alfonso

    2016-01-01

    [eng] The Ebro Delta-Estuary complex is one of the largest wetland areas in the western Mediterranean, and it is considered one of the most important estuarine zones in Europe. In 2013, the Ebro watershed, including its deltaic plain, was declared World Biosphere Reserve by the UNESCO. Due to its singularity, a total of 7.736 ha of Delta are protected under the Spanish Natural Park figure (including coastal lagoons, freshwater springs, bays and adjacent coastline) which stands out by its ...

  9. Effects of Alder Mine on the Water, Sediments, and Benthic Macroinvertebrates of Alder Creek, 1998 Annual Report.

    Energy Technology Data Exchange (ETDEWEB)

    Peplow, Dan

    1999-05-28

    The Alder Mine, an abandoned gold, silver, copper, and zinc mine in Okanogan County, Washington, produces heavy metal-laden effluent that affects the quality of water in a tributary of the Methow River. The annual mass loading of heavy metals from two audits at the Alder Mine was estimated to exceed 11,000 kg per year. In this study, water samples from stations along Alder Creek were assayed for heavy metals by ICP-AES and were found to exceed Washington State's acute freshwater criteria for cadmium (Cd), copper (Cu), selenium (Se), and zinc (Zn).

  10. Evaluating Ethanol-based Sample Preservation to Facilitate Use of DNA Barcoding in Routine Freshwater Biomonitoring Programs Using Benthic Macroinvertebrates

    Science.gov (United States)

    Molecular methods, such as DNA barcoding, have the potential in enhance biomonitoring programs worldwide. Altering routinely used sample preservation methods to protect DNA from degradation may pose a potential impediment to application of DNA barcoding and metagenomics for biom...

  11. Benthic macroinvertebrates as indicators of biological condition below hydropower dams on west slope Sierra Nevada streams, California, USA

    Science.gov (United States)

    Over 50 hydropower dams in California will undergo relicensing by the Federal Energy Regulatory Commission (FERC) in the next 15 years. An interpretive framework for biological data collected by relicensing studies is lacking. This study developed a multi-metric index of biotic...

  12. Near-field receiving water monitoring of trace metals and a benthic community near the Palo Alto Regional Water Quality Control Plant in south San Francisco Bay, California; 2015

    Science.gov (United States)

    Cain, Daniel J.; Thompson, Janet K.; Crauder, Jeffrey; Parchaso, Francis; Stewart, Robin; Turner, Matthew; Hornberger, Michelle I.; Luoma, Samuel N.

    2016-01-01

    Trace-metal concentrations in sediment and in the clam Macoma petalum (formerly reported as Macoma balthica), clam reproductive activity, and benthic macroinvertebrate community structure were investigated in a mudflat 1 kilometer south of the discharge of the Palo Alto Regional Water Quality Control Plant (PARWQCP) in South San Francisco Bay, California. This report includes data collected by U.S. Geological Survey (USGS) scientists for the period from January 2015 to December 2015. These data are appended to long-term datasets extending back to 1974, and serve as the basis for the City of Palo Alto’s Near-Field Receiving Water Monitoring Program, initiated in 1994.

  13. Near-field receiving water monitoring of trace metals and a benthic community near the Palo Alto Regional Water Quality Control Plant in South San Francisco Bay, California-2010

    Science.gov (United States)

    Dyke, Jessica; Parcheso, Francis; Thompson, Janet K.; Cain, Daniel J.; Luoma, Samuel N.; Hornberger, Michelle I.

    2011-01-01

    Trace-metal concentrations in sediment and in the clam Macoma petalum (formerly reported as Macoma balthica), clam reproductive activity, and benthic macroinvertebrate community structure were investigated in a mudflat 1 kilometer south of the discharge of the Palo Alto Regional Water Quality Control Plant (PARWQCP) in South San Francisco Bay, Calif. This report includes the data collected for the period January 2010 to December 2010 and extends a critical long-term biogeochemical record that dates back to 1974. These data serve as the basis for the City of Palo Alto's Near-Field Receiving Water Monitoring Program initiated in 1994.

  14. Interactions Between Hydropeaking and Thermopeaking Waves and Their Effect on the Benthic Community in Flume Simulations

    Science.gov (United States)

    Bruno, M.; Carolli, M.; Maiolini, B.; Siviglia, A.; Zolezzi, G.

    2013-12-01

    M. C. Bruno1*, M. Carolli2, B. Maiolini1, A. Siviglia2, Zolezzi, G.2 1 Fondazione Edmund Mach, Research and Innovation Centre. S. Michele all'Adige, I-38010, Italy 2 Department of Civil, Environmental and Mechanical Engineering, University of Trento, I-38100, Trento, Italy * cristina.bruno@fmach.it In Alpine regions, hydroelectricity generation is a key power source and its ability to quickly respond to short-term changes in energy demand makes it an ideal source to meet the needs of the deregulated energy market. This economic need is reflected in the temporal patterns of dam operations with consequences for the water bodies that receive downstream releases in the form of ';hydropeaking', typically consisting of sharp water releases in river reaches below dams. The unsteadiness related to this highly intermittent phenomenon has cascading effects on both biotic and abiotic river resources. Regulation by dams may also significantly affect the thermal regime of riversespecially in mountain areas, where releases from high-elevation reservoirs are often characterized by a markedly different temperature from that of the receiving body, thus causing also sharp water temperature variations, named ';thermopeaking'. While interacting with external forcing, the hydrodynamic and thermal waves propagate downstream with different celerities and a first phase of mutual overlap is followed by a second phase in which the two waves proceed separately. The asynchronous propagation of the two waves produces two distinct but consecutive impacts on the benthic community. Because it is difficult to disentangle the multiple effects of hydropeaking and thermopeaking on benthic macroinvertebrates in experiments conducted in natural conditions, we conducted our studies in an experimental structure of five steel channels directly fed by an alpine stream, the Fersina, a tributary to the Adige River of northern Italy. We simulated two sets of cold and warm thermopeaking waves, and measured the

  15. Climate change and glacier retreat drive shifts in an Antarctic benthic ecosystem.

    Science.gov (United States)

    Sahade, Ricardo; Lagger, Cristian; Torre, Luciana; Momo, Fernando; Monien, Patrick; Schloss, Irene; Barnes, David K A; Servetto, Natalia; Tarantelli, Soledad; Tatián, Marcos; Zamboni, Nadia; Abele, Doris

    2015-11-01

    The Antarctic Peninsula (AP) is one of the three places on Earth that registered the most intense warming in the last 50 years, almost five times the global mean. This warming has strongly affected the cryosphere, causing the largest ice-shelf collapses ever observed and the retreat of 87% of glaciers. Ecosystem responses, although increasingly predicted, have been mainly reported for pelagic systems. However, and despite most Antarctic species being benthic, responses in the Antarctic benthos have been detected in only a few species, and major effects at assemblage level are unknown. This is probably due to the scarcity of baselines against which to assess change. We performed repeat surveys of coastal benthos in 1994, 1998, and 2010, analyzing community structure and environmental variables at King George Island, Antarctica. We report a marked shift in an Antarctic benthic community that can be linked to ongoing climate change. However, rather than temperature as the primary factor, we highlight the resulting increased sediment runoff, triggered by glacier retreat, as the potential causal factor. The sudden shift from a "filter feeders-ascidian domination" to a "mixed assemblage" suggests that thresholds (for example, of tolerable sedimentation) and alternative equilibrium states, depending on the reversibility of the changes, could be possible traits of this ecosystem. Sedimentation processes will be increasing under the current scenario of glacier retreat, and attention needs to be paid to its effects along the AP. PMID:26702429

  16. Environmental changes during the Paleocene–Eocene Thermal Maximum in Spitsbergen as reflected by benthic foraminifera

    Directory of Open Access Journals (Sweden)

    Jenö Nagy

    2013-07-01

    Full Text Available The study deals with environmental changes during the Paleocene–Eocene Thermal Maximum (PETM and its background conditions in Spitsbergen through analysis of benthic foraminiferal assemblages (FA in a section drilled in the Paleogene Central Basin. The impact of this extreme global warming occurs here in prodelta shelf mudstones composing the lower part of the Gilsonryggen Member (Frysjaodden Formation. The start of the PETM perturbation is marked by a faunal turnover, in which the medium-diversity circumpolar Reticulophragmium assemblage was replaced by a low-diversity Trochammina fauna. During the hyperthermal period, benthic foraminiferal diversity decreased severely, while the dominance of small-sized taxa with epifaunal morphology strongly increased. This low-diversity fauna occurs in sediments with a reduced thorium/uranium ratio (proxy for oxygenation and kaolinite enrichment (proxy for high humidity. The faunal changes were thus caused by the combined effects of hypoxic and hyposaline conditions in a stratified water column, due to extreme warming with its accompanying intensified hydrologic cycle. The PETM acme coincides with the maximum flooding surface (MFS of the Gilsonryggen depositional sequence, composed of the Gilsonryggen Member and the overlying Battfjellet and Aspelintoppen formations. The transgressive phase of the sequence was initiated by local tectonics, while the eustatic sea-level rise of the PETM was superimposed on this transgression.To access the supplementary material for this article, please see supplementary files under Article Tools online.

  17. Exploring the links between natural products and bacterial assemblages in the sponge Aplysina aerophoba.

    Science.gov (United States)

    Sacristán-Soriano, Oriol; Banaigs, Bernard; Casamayor, Emilio O; Becerro, Mikel A

    2011-02-01

    The sponge Aplysina aerophoba produces a large diversity of brominated alkaloids (BAs) and hosts a complex microbial assemblage. Although BAs are located within sponge cells, the enzymes that bind halogen elements to organic compounds have been exclusively described in algae, fungi, and bacteria. Bacterial communities within A. aerophoba could therefore be involved in the biosynthesis of these compounds. This study investigates whether changes in both the concentration of BAs and the bacterial assemblages are correlated in A. aerophoba. To do so, we quantified major natural products using high-performance liquid chromatography and analyzed bacterial assemblages using denaturing gradient gel electrophoresis on the 16S rRNA gene. We identified multiple associations between bacteria and natural products, including a strong relationship between a Chloroflexi phylotype and aplysinamisin-1 and between an unidentified bacterium and aerophobin-2 and isofistularin-3. Our results suggest that these bacteria could either be involved in the production of BAs or be directly affected by them. To our knowledge, this is one of the first reports that find a significant correlation between natural products and bacterial populations in any benthic organism. Further investigating these associations will shed light on the organization and functioning of host-endobiont systems such as Aplysina aerophoba. PMID:21115701

  18. Characteristics of the Mesophotic Megabenthic Assemblages of the Vercelli Seamount (North Tyrrhenian Sea)

    Science.gov (United States)

    Bo, Marzia; Bertolino, Marco; Borghini, Mireno; Castellano, Michela; Covazzi Harriague, Anabella; Di Camillo, Cristina Gioia; Gasparini, GianPietro; Misic, Cristina; Povero, Paolo; Pusceddu, Antonio; Schroeder, Katrin; Bavestrello, Giorgio

    2011-01-01

    The biodiversity of the megabenthic assemblages of the mesophotic zone of a Tyrrhenian seamount (Vercelli Seamount) is described using Remotely Operated Vehicle (ROV) video imaging from 100 m depth to the top of the mount around 61 m depth. This pinnacle hosts a rich coralligenous community characterized by three different assemblages: (i) the top shows a dense covering of the kelp Laminaria rodriguezii; (ii) the southern side biocoenosis is mainly dominated by the octocorals Paramuricea clavata and Eunicella cavolinii; while (iii) the northern side of the seamount assemblage is colonized by active filter-feeding organisms such as sponges (sometimes covering 100% of the surface) with numerous colonies of the ascidian Diazona violacea, and the polychaete Sabella pavonina. This study highlights, also for a Mediterranean seamount, the potential role of an isolated rocky peak penetrating the euphotic zone, to work as an aggregating structure, hosting abundant benthic communities dominated by suspension feeders, whose distribution may vary in accordance to the geomorphology of the area and the different local hydrodynamic conditions. PMID:21304906

  19. Shift in a large river fish assemblage: body-size and trophic structure dynamics.

    Directory of Open Access Journals (Sweden)

    Kyle J Broadway

    Full Text Available As the intensity and speed of environmental change increase at both local and global scales it is imperative that we gain a better understanding of the ecological implications of community shifts. While there has been substantial progress toward understanding the drivers and subsequent responses of community change (e.g. lake trophic state, the ecological impacts of food web changes are far less understood. We analyzed Wabash River fish assemblage data collected from 1974-2008, to evaluate temporal variation in body-size structure and functional group composition. Two parameters derived from annual community size-spectra were our major response variables: (1 the regression slope is an index of ecological efficiency and predator-prey biomass ratios, and (2 spectral elevation (regression midpoint height is a proxy for food web capacity. We detected a large assemblage shift, over at least a seven year period, defined by dramatic changes in abundance (measured as catch-per-unit-effort of the dominant functional feeding groups among two time periods; from an assemblage dominated by planktivore-omnivores to benthic invertivores. There was a concurrent increase in ecological efficiency (slopes increased over time following the shift associated with an increase in large-bodied low trophic level fish. Food web capacity remained relatively stable with no clear temporal trends. Thus, increased ecological efficiency occurred simultaneous to a compensatory response that shifted biomass among functional feeding groups.

  20. Characteristics of the mesophotic megabenthic assemblages of the vercelli seamount (north tyrrhenian sea.

    Directory of Open Access Journals (Sweden)

    Marzia Bo

    Full Text Available The biodiversity of the megabenthic assemblages of the mesophotic zone of a Tyrrhenian seamount (Vercelli Seamount is described using Remotely Operated Vehicle (ROV video imaging from 100 m depth to the top of the mount around 61 m depth. This pinnacle hosts a rich coralligenous community characterized by three different assemblages: (i the top shows a dense covering of the kelp Laminaria rodriguezii; (ii the southern side biocoenosis is mainly dominated by the octocorals Paramuricea clavata and Eunicella cavolinii; while (iii the northern side of the seamount assemblage is colonized by active filter-feeding organisms such as sponges (sometimes covering 100% of the surface with numerous colonies of the ascidian Diazona violacea, and the polychaete Sabella pavonina. This study highlights, also for a Mediterranean seamount, the potential role of an isolated rocky peak penetrating the euphotic zone, to work as an aggregating structure, hosting abundant benthic communities dominated by suspension feeders, whose distribution may vary in accordance to the geomorphology of the area and the different local hydrodynamic conditions.

  1. Implication of salt marsh foraminiferal assemblages in Suncheon Bay, South Korea

    Science.gov (United States)

    Jeong, Da Un; Lee, Yeon Gyu; Kang, Sora; Kim, Shin; Lee, Jung Sick

    2016-03-01

    Analyses of the compositions of benthic foraminifera and sediment, observations of tidal level and salinity, and a geographic survey of the tidal salt marsh in Suncheon Bay were conducted to examine the vertical distribution of foraminifera and evaluate their potential use for sea level studies. The salt marsh is composed mainly of fine-grained silty clay sediment and its salinity is below approximately 11 psu. The tidal current flows in the southwest-tonortheast direction with an average velocity of 26.57 cm/s. A total of 33 species of foraminifera (17 agglutinated and 16 calcareoushyaline) belonging to 24 genera was identified. The species diversity (1.1 on average) was relatively low. Dominant species were Ammonia beccarii, Miliammina fusca, Haplophragmoides wilberti, and Jadammina macrescens. Calcareous foraminifera (29.5%) were dominantly represented by the Ammonia beccarii assemblage, which characterized the region between mean tide level and mean low high water (MLHW). Agglutinated species (70.5%) were represented mostly by Miliammina fusca, Miliammina fusca-Haplophragmoides wilberti, and Haplophragmoides wilberti assemblages, which characterized the MLHW-mean high water (MHW), MHW-mean highest high water (MHHW), and MHHW-Approx. highest high water tide levels, respectively. In particular, the Haplophragmoides wilberti assemblage is believed to represent the highest elevation zone of foraminifera in the salt marshes of Suncheon Bay and is considered to be a reliable indicator of sea level as a result of its narrow vertical range.

  2. BENTHIC FORAMINIFERA AS INDICATORS OF PALEOECOLOGIC