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Sample records for macroinvertebrates fish small

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

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    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.

  2. Fish stomach contents in benthic macroinvertebrate assemblage assessments

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    TH. Tupinambás

    Full Text Available The choice of sampling gears to assess benthic macroinvertebrate communities depends on environmental characteristics, study objectives, and cost effectiveness. Because of the high foraging capacity and diverse habitats and behaviors of benthophagous fishes, their stomach contents may offer a useful sampling tool in studies of benthic macroinvertebrates, especially in large, deep, fast rivers that are difficult to sample with traditional sediment sampling gear. Our objective was to compare the benthic macroinvertebrate communities sampled from sediments with those sampled from fish stomachs. We collected benthic macroinvertebrates and fish from three different habitat types (backwater, beach, riffle in the wet season, drying season, and dry season along a single reach of the Grande River (Paraná River Basin, southeast Brazil. We sampled sediments through use of a Petersen dredge (total of 216 grabs and used gill nets to sample fish (total of 36 samples. We analyzed the stomach contents of three commonly occurring benthophagous fish species (Eigenmannia virescens, Iheringichthys labrosus, Leporinus amblyrhynchus. Chironomids dominated in both sampling methods. Macroinvertebrate taxonomic composition and abundances from fish stomachs differed from those from sediment samples, but less so from riffles than from backwater and beach habitats. Macroinvertebrate taxa from E. virescens stomachs were more strongly correlated with sediment samples from all three habitats than were those from the other two species. The species accumulation curves and higher mean dispersion values, compared with with sediment samples suggest that E. virescens is more efficient than sediment samples and the other fish studied at collecting benthic taxa. We conclude that by analyzing the stomach contents of benthophagous fishes it is possible to assess important characteristics of benthic communities (dispersion, taxonomic composition and diversity. This is especially true

  3. Turnover patterns in fish versus macroinvertebrates — implications ...

    African Journals Online (AJOL)

    Spatial patterns in taxonomic richness and turnover for fish and aquatic macroinvertebrates are compared to assess the relative usefulness of each taxonomic group in mapping biodiversity patterns. Fish and aquatic macroinvertebrate species data for sites down the longitudinal axes of nine rivers in four provinces along the ...

  4. Macroinvertebrates as indicators of fish absence in naturally fishless lakes

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    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

  5. Effects of Management Legacies on Stream Fish and Aquatic Benthic Macroinvertebrate Assemblages

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    Quist, Michael C.; Schultz, Randall D.

    2014-09-01

    Fish and benthic macroinvertebrate assemblages often provide insight on ecological conditions for guiding management actions. Unfortunately, land use and management legacies can constrain the structure of biotic communities such that they fail to reflect habitat quality. The purpose of this study was to describe patterns in fish and benthic macroinvertebrate assemblage structure, and evaluate relationships between biota and habitat characteristics in the Chariton River system of south-central Iowa, a system likely influenced by various potential management legacies (e.g., dams, chemical removal of fishes). We sampled fishes, benthic macroinvertebrates, and physical habitat from a total of 38 stream reaches in the Chariton River watershed during 2002-2005. Fish and benthic macroinvertebrate assemblages were dominated by generalist species tolerant of poor habitat quality; assemblages failed to show any apparent patterns with regard to stream size or longitudinal location within the watershed. Metrics used to summarize fish assemblages and populations [e.g., presence-absence, relative abundance, Index of Biotic Integrity for fish (IBIF)] were not related to habitat characteristics, except that catch rates of piscivores were positively related to the depth and the amount of large wood. In contrast, family richness of benthic macroinvertebrates, richness of Ephemeroptera, Trichoptera, and Plecoptera taxa, and IBI values for benthic macroinvertebrates (IBIBM) were positively correlated with the amount of overhanging vegetation and inversely related to the percentage of fine substrate. A long history of habitat alteration by row-crop agriculture and management legacies associated with reservoir construction has likely resulted in a fish assemblage dominated by tolerant species. Intolerant and sensitive fish species have not recolonized streams due to downstream movement barriers (i.e., dams). In contrast, aquatic insect assemblages reflected aquatic habitat, particularly

  6. Trophic relationships between macroinvertebrates and fish in a pampean lowland stream (Argentina

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    María V. López van Oosterom

    2013-03-01

    Full Text Available The diet and trophic relationships between the macroinvertebrates Phyllogomphoides joaquini Rodrigues Capítulo, 1992 and Coenagrionidae (Odonata, Chironomidae (Diptera, Diplodon delodontus (Lamarck, 1919 (Bivalvia: Hyriidae, and Pomacea canaliculata (Lamarck, 1822 (Gastropoda: Ampulariidae and the fishes Pimelodella laticeps Eigenmann, 1917 (Heptapteridae and Bryconamericus iheringii (Boulenger, 1887 (Characidae in a temperate lowland lotic system in Argentina were assessed on the basis of gut contents and stable-isotope analyses. The feeding strategies were analyzed by the AMUNDSEN method. Relative food items contribution for the taxa studied indicated a generalist-type trophic strategy. In macroinvertebrates, in general, the values of stable isotope confirmed the result of the analysis of gut contents. With the fish, stable-isotope analysis demonstrated that both species are predators, although B. iheringii exhibited a more omnivorous behaviour. These feeding studies allowed us to determine the trophic relationships among taxa studied. Detritus and diatoms were a principal source of food for all the macroinvertebrates studied. In La Choza stream the particulate organic matter is a major no limited food resource, has a significant influence upon the community.

  7. Combined effects of water stress and pollution on macroinvertebrate and fish assemblages in a Mediterranean intermittent river.

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    Kalogianni, Eleni; Vourka, Aikaterini; Karaouzas, Ioannis; Vardakas, Leonidas; Laschou, Sofia; Skoulikidis, Nikolaos Th

    2017-12-15

    Water stress is a key stressor in Mediterranean intermittent rivers exacerbating the negative effects of other stressors, such as pollutants, with multiple effects on different river biota. The current study aimed to determine the response of macroinvertebrate and fish assemblages to instream habitat and water chemistry, at the microhabitat scale and at different levels of water stress and pollution, in an intermittent Mediterranean river. Sampling was conducted at high and low summer discharge, at two consecutive years, and included four reaches that were targeted for their different levels of water stress and pollution. Overall, the macroinvertebrate fauna of Evrotas River indicated high resilience to intermittency, however, variation in community structure and composition occurred under acute water stress, due to habitat alteration and change in water physico-chemistry, i.e. water temperature increase. The combined effects of pollution and high water stress had, however, pronounced effects on species richness, abundance and community structure in the pollution impacted reach, where pollution sensitive taxa were almost extirpated. Fish response to drought, in reaches free of pollution, consisted of an increase in the abundance of the two small limnophilic species, coupled with their shift to faster flowing riffle habitats, and a reduction in the abundance of the larger, rheophilic species. In the pollution impacted reach, however, the combination of pollution and high water stress led to hypoxic conditions assumed to be the leading cause of the almost complete elimination of the fish assemblage. In contrast, the perennial Evrotas reaches with relatively stable physicochemical conditions, though affected hydrologically by drought, appear to function as refugia for fish during high water stress. When comparing the response of the two biotic groups to combined acute water stress and pollution, it is evident that macroinvertebrates were negatively impacted, but fish

  8. Patterns of Macroinvertebrate and Fish Diversity in Freshwater Sulphide Springs

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    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.

  9. Community-level response of fishes and aquatic macroinvertebrates to stream restoration in a third-order tributary of the Potomac River, USA

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    Selego, Stephen M.; Rose, Charnee L.; Merovich, George T.; Welsh, Stuart A.; Anderson, James T.

    2012-01-01

    Natural stream channel design principles and riparian restoration practices were applied during spring 2010 to an agriculturally impaired reach of the Cacapon River, a tributary of the Potomac River which flows into the Chesapeake Bay. Aquatic macroinvertebrates and fishes were sampled from the restoration reach, two degraded control, and two natural reference reaches prior to, concurrently with, and following restoration (2009 through 2010). Collector filterers and scrapers replaced collector gatherers as the dominant macroinvertebrate functional feeding groups in the restoration reach. Before restoration, based on indices of biotic integrity (IBI), the restoration reach fish and macroinvertebrate communities closely resembled those sampled from the control reaches, and after restoration more closely resembled those from the reference reaches. Although the macroinvertebrate community responded more favorably than the fish community, both communities recovered quickly from the temporary impairment caused by the disturbance of restoration procedures and suggest rapid improvement in local ecological conditions.

  10. Community-Level Response of Fishes and Aquatic Macroinvertebrates to Stream Restoration in a Third-Order Tributary of the Potomac River, USA

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    Stephen M. Selego

    2012-01-01

    Full Text Available Natural stream channel design principles and riparian restoration practices were applied during spring 2010 to an agriculturally impaired reach of the Cacapon River, a tributary of the Potomac River which flows into the Chesapeake Bay. Aquatic macroinvertebrates and fishes were sampled from the restoration reach, two degraded control, and two natural reference reaches prior to, concurrently with, and following restoration (2009 through 2010. Collector filterers and scrapers replaced collector gatherers as the dominant macroinvertebrate functional feeding groups in the restoration reach. Before restoration, based on indices of biotic integrity (IBI, the restoration reach fish and macroinvertebrate communities closely resembled those sampled from the control reaches, and after restoration more closely resembled those from the reference reaches. Although the macroinvertebrate community responded more favorably than the fish community, both communities recovered quickly from the temporary impairment caused by the disturbance of restoration procedures and suggest rapid improvement in local ecological conditions.

  11. Does diet influence consumer nutrient cycling? Macroinvertebrate and fish excretion in streams

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    Ryan McManamay; Jackson Webster; H. Valett; C. Dolloff

    2011-01-01

    Consumer nutrient cycling supplies limiting elements to autotrophic and heterotrophic organisms in aquatic systems. However, the role of consumers in supplying nutrients may change depending on their diet and their own stoichiometry. We evaluated the stoichiometry, N and P excretion, and diets of the dominant macroinvertebrates and fish at 6 stream sites to determine...

  12. L-Lake macroinvertebrate community

    International Nuclear Information System (INIS)

    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

  13. 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.

  14. Mercury in fish and macroinvertebrates from New York's streams and rivers: A compendium of data sources

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    Riva-Murray, Karen; Burns, Douglas A.

    2016-01-01

    The U.S. Geological Survey has compiled a list of existing data sets, from selected sources, containing mercury (Hg) concentration data in fish and macroinvertebrate samples that were collected from flowing waters of New York State from 1970 through 2014. Data sets selected for inclusion in this report were limited to those that contain fish and (or) macroinvertebrate data that were collected across broad areas, cover relatively long time periods, and (or) were collected as part of a broader-scale (e.g. national) study or program. In addition, all data sets listed were collected, processed, and analyzed with documented methods, and contain critical sample information (e.g. fish species, fish size, Hg species) that is needed to analyze and interpret the reported Hg concentration data. Fourteen data sets, all from state or federal agencies, are listed in this report, along with selected descriptive information regarding each data source and data set contents. Together, these 14 data sets contain Hg and related data for more than 7,000 biological samples collected from more than 700 unique stream and river locations between 1970 and 2014.

  15. Small-scale habitat structure modulates the effects of no-take marine reserves for coral reef macroinvertebrates.

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    Pascal Dumas

    Full Text Available No-take marine reserves are one of the oldest and most versatile tools used across the Pacific for the conservation of reef resources, in particular for invertebrates traditionally targeted by local fishers. Assessing their actual efficiency is still a challenge in complex ecosystems such as coral reefs, where reserve effects are likely to be obscured by high levels of environmental variability. The goal of this study was to investigate the potential interference of small-scale habitat structure on the efficiency of reserves. The spatial distribution of widely harvested macroinvertebrates was surveyed in a large set of protected vs. unprotected stations from eleven reefs located in New Caledonia. Abundance, density and individual size data were collected along random, small-scale (20×1 m transects. Fine habitat typology was derived with a quantitative photographic method using 17 local habitat variables. Marine reserves substantially augmented the local density, size structure and biomass of the target species. Density of Trochus niloticus and Tridacna maxima doubled globally inside the reserve network; average size was greater by 10 to 20% for T. niloticus. We demonstrated that the apparent success of protection could be obscured by marked variations in population structure occurring over short distances, resulting from small-scale heterogeneity in the reef habitat. The efficiency of reserves appeared to be modulated by the availability of suitable habitats at the decimetric scale ("microhabitats" for the considered sessile/low-mobile macroinvertebrate species. Incorporating microhabitat distribution could significantly enhance the efficiency of habitat surrogacy, a valuable approach in the case of conservation targets focusing on endangered or emblematic macroinvertebrate or relatively sedentary fish species.

  16. The Colonization of Newly Built Fishponds by the Macroinvertebrate Assemblages

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    Pavla Řezníčková

    2016-01-01

    Full Text Available The succession of standing waters by aquatic macroinvertebrates is a present and insufficiently surveyed topic. This study is addressed to the issue of colonisation of newly created small standing waters. Two fishponds situated in the north of Moravia (Czech Republic were studied. The aim of this study was to determine the character and colonisation rate of these ponds by macroinvertebrates, to evaluate the abundance, taxonomic composition and changes in composition of freshwater assemblages as a result of the fish stock influence. Basic abiotic parameters were also measured within the sampling occasions (e.g. water temperature, dissolved oxygen, conductivity, pH, total nitrogen and phosphorus concentrations. Samples of aquatic macroinvertebrates were taken monthly during the years 2012 and 2013, by kick sampling method using the hand net. The character of sampled fishponds was very similar, environmental parameters (e.g. area, substrate, depth etc. were comparable. The colonisation of both fishponds was very fast. The pioneer colonists were mainly insect larvae (e.g. chironomids. Very low numbers of macroinvertebrates as a result of fish stock influence were recorded on both sites during the observation with the highest abundances in summer season.

  17. Macroinvertebrate Prey Availability and Fish Diet Selectivity in Relation to Environmental Variables in Natural and Restoring North San Francisco Bay Tidal Marsh Channels

    OpenAIRE

    Emily R. Howe; Charles A. Simenstad; Jason D. Toft; Jeffrey R. Cordell; Stephen M. Bollens

    2014-01-01

    Tidal marsh wetlands provide important foraging habitat for a variety of estuarine fishes. Prey organisms include benthic–epibenthic macroinvertebrates, neustonic arthropods, and zooplankton. Little is known about the abundance and distribution of interior marsh macroinvertebrate communities in the San Francisco Estuary (estuary). We describe seasonal, regional, and site variation in the composition and abundance of neuston and benthic–epibenthic macroinvertebrates that inhabit tidal marsh ch...

  18. Fish but Not Macroinvertebrates Promote Trophic Cascading Effects in High Density Submersed Plant Experimental Lake Food Webs in Two Contrasting Climate Regions

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    Carlos Iglesias

    2017-07-01

    Full Text Available Predators play a key role in the functioning of shallow lakes. Differences between the response of temperate and subtropical systems to fish predation have been proposed, but experimental evidence is scarce. To elucidate cascading effects produced by predators in contrasting climatic zones, we conducted a mesocosm experiment in three pairs of lakes in Uruguay and Denmark. We used two typical planktivorous-omnivorous fish species (Jenynsia multidentata + Cnesterodon decemmaculatus and Gasterosteus aculeatus + Perca fluviatilis and one littoral omnivorous-predatory macroinvertebrate (Palaemonetes argentinus and Gammarus lacustris, alone and combined, in numbers resembling natural densities. Fish predation on zooplankton increased phytoplankton biomass in both climate zones, whereas the effects of predatory macroinvertebrates on zooplankton and phytoplankton were not significant in either climate zone. Macroinvertebrates (that freely colonized the sampling devices were diminished by fish in both climate areas; however, periphyton biomass did not vary among treatments. Our experiments demonstrated that fish affected the structure of both planktonic and littoral herbivorous communities in both climate regions, with a visible positive cascading effect on phytoplankton biomass, but no effects on periphyton. Altogether, fish impacts appeared to be a strong driver of turbid water conditions in shallow lakes regardless of climatic zone by indirectly contributing to increasing phytoplankton biomass.

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

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    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...

  20. Macroinvertebrate Prey Availability and Fish Diet Selectivity in Relation to Environmental Variables in Natural and Restoring North San Francisco Bay Tidal Marsh Channels

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    Emily R. Howe

    2014-03-01

    Full Text Available Tidal marsh wetlands provide important foraging habitat for a variety of estuarine fishes. Prey organisms include benthic–epibenthic macroinvertebrates, neustonic arthropods, and zooplankton. Little is known about the abundance and distribution of interior marsh macroinvertebrate communities in the San Francisco Estuary (estuary. We describe seasonal, regional, and site variation in the composition and abundance of neuston and benthic–epibenthic macroinvertebrates that inhabit tidal marsh channels, and relate these patterns to environmental conditions. We also describe spatial and temporal variation in diets of marsh-associated inland silverside, yellowfin goby, and western mosquitofish. Fish and invertebrates were sampled quarterly from October 2003 to June 2005 at six marsh sites located in three river systems of the northern estuary: Petaluma River, Napa River, and  the west Delta. Benthic/epibenthic macroinvertebrates and neuston responded to environmental variables related to seasonal changes (i.e., temperature, salinity, as well as those related to marsh structure (i.e., vegetation, channel edge. The greatest variation in abundance occurred seasonally for neuston and spatially for benthic–epibenthic organisms, suggesting that each community responds to different environmental drivers. Benthic/epibenthic invertebrate abundance and diversity was lowest in the west Delta, and increased with increasing salinity. Insect abundance increased during the spring and summer, while Collembolan (springtail abundance increased during the winter. Benthic/epibenthic macroinvertebrates dominated fish diets, supplemented by insects, with zooplankton playing a minor role. Diet compositions of the three fish species overlapped considerably, with strong selection indicated for epibenthic crustaceans—a surprising result given the typical classification of Menidia beryllina as a planktivore, Acanthogobius flavimanus as a benthic predator, and Gambusia

  1. Effects of sea lamprey substrate modification and carcass nutrients on macroinvertebrate assemblages in a small Atlantic coastal stream

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    Weaver, Daniel M.; Coghlan, Stephen M.; Zydlewski, Joseph D.

    2018-01-01

    Aquatic macroinvertebrates respond to patch dynamics arising from interactions of physical and chemical disturbances across space and time. Anadromous fish, such as sea lamprey, Petromyzon marinus, migrate from the ocean and alter physical and chemical properties of recipient spawning streams. Sea lamprey disturb stream benthos physically through nest construction and spawning, and enrich food webs through nutrient deposition from decomposing carcasses. Sea lamprey spawning nests support greater macroinvertebrate abundance than adjacent reference areas, but concurrent effects of stream bed modification and nutrient supplementation have not been examined sequentially. We added carcasses and cleared substrate experimentally to mimic the physical disturbance and nutrient enrichment associated with lamprey spawning, and characterized effects on macroinvertebrate assemblage structure. We found that areas receiving cleared substrate and carcass nutrients were colonized largely by Simuliidae compared to upstream and downstream control areas that were colonized largely by Hydropsychidae, Philopotamidae, and Chironomidae. Environmental factors such as stream flow likely shape assemblages by physically constraining macroinvertebrate establishment and feeding. Our results indicate potential changes in macroinvertebrate assemblages from the physical and chemical changes to streams brought by spawning populations of sea lamprey.

  2. Eco-hydrologic model cascades: Simulating land use and climate change impacts on hydrology, hydraulics and habitats for fish and macroinvertebrates.

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    Guse, Björn; Kail, Jochem; Radinger, Johannes; Schröder, Maria; Kiesel, Jens; Hering, Daniel; Wolter, Christian; Fohrer, Nicola

    2015-11-15

    Climate and land use changes affect the hydro- and biosphere at different spatial scales. These changes alter hydrological processes at the catchment scale, which impact hydrodynamics and habitat conditions for biota at the river reach scale. In order to investigate the impact of large-scale changes on biota, a cascade of models at different scales is required. Using scenario simulations, the impact of climate and land use change can be compared along the model cascade. Such a cascade of consecutively coupled models was applied in this study. Discharge and water quality are predicted with a hydrological model at the catchment scale. The hydraulic flow conditions are predicted by hydrodynamic models. The habitat suitability under these hydraulic and water quality conditions is assessed based on habitat models for fish and macroinvertebrates. This modelling cascade was applied to predict and compare the impacts of climate- and land use changes at different scales to finally assess their effects on fish and macroinvertebrates. Model simulations revealed that magnitude and direction of change differed along the modelling cascade. Whilst the hydrological model predicted a relevant decrease of discharge due to climate change, the hydraulic conditions changed less. Generally, the habitat suitability for fish decreased but this was strongly species-specific and suitability even increased for some species. In contrast to climate change, the effect of land use change on discharge was negligible. However, land use change had a stronger impact on the modelled nitrate concentrations affecting the abundances of macroinvertebrates. The scenario simulations for the two organism groups illustrated that direction and intensity of changes in habitat suitability are highly species-dependent. Thus, a joined model analysis of different organism groups combined with the results of hydrological and hydrodynamic models is recommended to assess the impact of climate and land use changes on

  3. Biological assessment of aquaculture effects on effluent-receiving streams in Ghana using structural and functional composition of fish and macroinvertebrate assemblages.

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    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.

  4. 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.

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

    2014-07-14

    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.

  5. 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

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    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.

  6. 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

  7. Eucalypt plantations reduce the diversity of macroinvertebrates in small forested streams

    Directory of Open Access Journals (Sweden)

    Cordero–Rivera, A.

    2017-01-01

    Full Text Available Land use patterns of a river basin have a significant effect on the structure and function of river ecosystems. Changes in the composition of riparian plant communities modify the quantity, quality and seasonality of leaf–litter inputs, determining changes in macroinvertebrate colonization and activity. The main goal of this study was to test the effect of land–use modifications, and particularly the impact of eucalypt plantations, on the macroinvertebrate communities of sixteen headwater streams. Macroinvertebrates were counted and identified to family level. Land uses were classified in five categories using aerial photography: native forest, eucalypt plantations, agricultural land, shrubland, and urban areas. We found that macroinvertebrate diversity increased with basin size and with the proportion of basin covered by native forest. This variable correlated negatively with the land occupied by eucalypt plantations. Macroinvertebrate richness diminished with the increase of land surface covered by eucalypt plantations, and a similar tendency was observed with diversity. Furthermore, streams whose drainage basin was mainly covered by Eucalyptus were more likely to dry up in summer. This observation adds to evidence from previous studies that concluded that fast–growing tree plantations affect hydric resources, an important ecosystem service in the context of global warming. To minimize the impact of industrial sylviculture, we suggest that maintaining and/or restoring riparian forests could mitigate the effects of intensive eucalypt monocultures.

  8. Synthesis of the state of knowledge about species richness of macroalgae, macroinvertebrates and fishes in coastal and oceanic waters of Easter and Salas y Gómez islands

    Directory of Open Access Journals (Sweden)

    Miriam Fernández

    2014-10-01

    Full Text Available From the beginning of the 19th century on, several small sampling trips as well as large national and international scientific expeditions have been carried out to Easter Island (EI and Salas y Gómez Island (SGI. The objective of this study is to compile, synthesize and analyze published information about the biodiversity of macroalgae, macroinvertebrates and fishes associated with EI-SGI, updating the state of knowledge and making it available for the development of conservation plans. We searched all the available sources of information, such as scientific publications, scientific expeditions, fisheries data, technical reports, books, databases and online sources. We found 964 species reported within EI-SGI (143 species of macroalgae, 605 macroinvertebrates and 216 fishes, the majority for EI (923; for SGI 171 species have been reported. Species richness has increased over time, without leveling off, as sampling effort increases. However, seamounts and hydrothermal vents have been poorly studied in Chile's Exclusive Economic Zone (EEZ. A high percentage of endemism has been determined for the majority of the taxonomic groups, with mollusks and poriferans exhibiting the highest levels of endemism (33 -34%. Thus, the Rapanuian biogeographic province can be clearly identified, but information to differentiate between EI and SGI, and direct island-specific conservation efforts, is lacking. Nevertheless, the most vulnerable yet unprotected habitats (hydrothermal vents, higher diversity of seamounts size are located towards the western limit of the EEZ.

  9. Preliminary study of some environmental and ecological aspects of the communities of fish and aquatic macro-invertebrates in the Tutunendo River, Choco, Colombia

    International Nuclear Information System (INIS)

    Torres, Yenecith; Roldan, Gabriel; Asprilla, Sonia; Rivas, Tulia Sofia

    2006-01-01

    From June to October 2003 studies related to environmental and ecological aspects of fishes and macro-invertebrates in three sampling stations of Tutunendo River located in the Department of Choco, Colombia, were carried out. Abiotic factors like conductivity, pH, oxygen and temperature were also measured. Eighty one hundred fish specimens, belonging to three orders, seven families and twelve species were collected. The order Siluriformes presented the greatest abundance (70.72%) with three families, seven species and 128 specimens, followed by Characiformes with three families, three species and 43 specimens (23.53%). At the same time 1.211 aquatic macro-invertebrates were collected represented by the orders Ephemeroptera (50.28%), Odonata (11.40%), Coleoptera (8.67%), Hemiptera (8.42%), Trichoptera (7.30%), Plecoptera (5.7%), Megaloptera (3.3%), Lepidoptera (2.31%), Diptera (0.37%) and Haplotaxida (0.08%). The families Leptophlebiidae (37.24%), followed by Naucoridae (8.42%) and Baetidae (8%) were the most represented. Relationship between fishes and macro invertebrates as food items in Geophagus pellegrini and Astyanaxfasciatus were also studied. G. pellegrini was zooplanctophage with preference for Baetidae, Leptohyphidae, Hydrobiosidae, Leptoceridae and Naucoridae. Finally, the present work indicated that Tutunendo town does not have potential fishery; the economy is supported in productive traditional systems based in the agriculture, complemented with fishery and extractive activities

  10. Congruence in demersal fish, macroinvertebrate, and macroalgal community turnover on shallow temperate reefs.

    Science.gov (United States)

    Thomson, Russell J; Hill, Nicole A; Leaper, Rebecca; Ellis, Nick; Pitcher, C Roland; Barrett, Neville S; Edgar, Graham J

    2014-03-01

    To support coastal planning through improved understanding of patterns of biotic and abiotic surrogacy at broad scales, we used gradient forest modeling (GFM) to analyze and predict spatial patterns of compositional turnover of demersal fishes, macroinvertebrates, and macroalgae on shallow, temperate Australian reefs. Predictive models were first developed using environmental surrogates with estimates of prediction uncertainty, and then the efficacy of the three assemblages as biosurrogates for each other was assessed. Data from underwater visual surveys of subtidal rocky reefs were collected from the southeastern coastline of continental Australia (including South Australia and Victoria) and the northern coastline of Tasmania. These data were combined with 0.01 degree-resolution gridded environmental variables to develop statistical models of compositional turnover (beta diversity) using GFM. GFM extends the machine learning, ensemble tree-based method of random forests (RF), to allow the simultaneous modeling of multiple taxa. The models were used to generate predictions of compositional turnover for each of the three assemblages within unsurveyed areas across the 6600 km of coastline in the region of interest. The most important predictor for all three assemblages was variability in sea surface temperature (measured as standard deviation from measures taken interannually). Spatial predictions of compositional turnover within unsurveyed areas across the region of interest were remarkably congruent across the three taxa. However, the greatest uncertainty in these predictions varied in location among the different assemblages. Pairwise congruency comparisons of observed and predicted turnover among the three assemblages showed that invertebrate and macroalgal biodiversity were most similar, followed by fishes and macroalgae, and lastly fishes and invertebrate biodiversity, suggesting that of the three assemblages, macroalgae would make the best biosurrogate for

  11. Aquatic-macroinvertebrate communities of Prairie-Pothole wetlands and lakes under a changed climate

    Science.gov (United States)

    McLean, Kyle I.; Mushet, David M.; Renton, David A.; Stockwell, Craig A.

    2016-01-01

    Understanding how aquatic-macroinvertebrate communities respond to changes in climate is important for biodiversity conservation in the Prairie Pothole Region and other wetland-rich landscapes. We sampled macroinvertebrate communities of 162 wetlands and lakes previously sampled from 1966 to 1976, a much drier period compared to our 2012–2013 sampling timeframe. To identify possible influences of a changed climate and predation pressures on macroinvertebrates, we compared two predictors of aquatic-macroinvertebrate communities: ponded-water dissolved-ion concentration and vertebrate-predator presence/abundance. Further, we make inferences of how macroinvertebrate communities were structured during the drier period when the range of dissolved-ion concentrations was much greater and fish occurrence in aquatic habitats was rare. We found that aquatic-macroinvertebrate community structure was influenced by dissolved-ion concentrations through a complex combination of direct and indirect relationships. Ion concentrations also influenced predator occurrence and abundance, which indirectly affected macroinvertebrate communities. It is important to consider both abiotic and biotic gradients when predicting how invertebrate communities will respond to climate change. Generally, in the wetlands and lakes we studied, freshening of ponded water resulted in more homogenous communities than occurred during a much drier period when salinity range among sites was greater.

  12. 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.

  13. 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...... the mean weight-specific respiratory rate of macroinvertebrates declined by only 50%, from 400 to 3800 m. We suggest that this disproportionately large gap between availability and demand of oxygen at high altitudes may imply a potential oxygen deficiency for the fauna, and we discuss how oxygen deficiency...

  14. 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.).

  15. Macroinvertebrate Community responses to gravel addition in a Southeastern regulated river

    Science.gov (United States)

    Ryan A. McManamay; Donald J. Orth; A. Charles. Dolloff

    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...

  16. Assessing Ecosystem Integrity And Macroinvertebrates Community Structure Towards Conservation Of Small Streams In Tanzania

    Directory of Open Access Journals (Sweden)

    Fredrick Ojija

    2017-02-01

    Full Text Available This study attempts to use biological indices such as Biological Monitoring Working Party BMWP Average Score Per Taxa ASPT and Hilsenhoff Family Biotic Index FBI in order to determine the ecosystem health and water quality of Nzovwe stream in Mbeya Tanzania. Macroinvertebrates were sampled from Nzovwe stream using semi-quantitative techniques from March to June 2016. About 500 meters of Nzovwe stream was divided into 5 sampling sites each site was 100 meters apart. The macroinvertebrates were collected from all the possible microhabitats of each site using a 250m mesh size D- frame kick net. Macroinvertebrate specimens were preserved in the 70 ethyl alcohol in the polyethylene bottles. The samples were identified to the family level using standard identification keys. The BMWP score and ASPT score indicated good and moderate stream water quality respectively. The FBI showed the stream had possibility of some organic pollution. The Shannon-Wiener diversity index shows the sampling sites were moderately polluted or possibly impaired. Macroinvertebrates in pollution class II were abundant suggesting moderate pollution. Moreover the Midge Insects Diptera and Snail indicated the stream water quality or ecosystem health is between unimpaired and possibly impaired. Based on these results the study concludes that the stream ecosystem is moderately polluted and therefore the study recommends a regular stream monitoring.

  17. Influence of riparian canopy on macroinvertebrate composition and food habits of juvenile salmonids in several Oregon streams.

    Science.gov (United States)

    William R. Meehan

    1996-01-01

    The community composition of macroinvertebrates and the feeding habits of juvenile salmonids were studied in eight Oregon streams. Benthic, drift, sticky trap, and water trap samples were taken over a 3-year period, along with stomach samples of the fish. Samples were taken in stream reaches with and without riparian canopy. Both main effects—fish diet versus...

  18. Effects of Student-Induced Trampling on Aquatic Macroinvertebrates in Agricultural Headwater Streams

    Directory of Open Access Journals (Sweden)

    Jon P. Bossley

    2018-01-01

    Full Text Available Outdoor education (OE stream classes provide students with an opportunity to gain hands-on experience with sampling methods for evaluating stream water quality. Trampling by students as a result of stream classes may disrupt the substrate and negatively impact aquatic macroinvertebrates. The impact of student-induced trampling in headwaters as a result of stream classes on aquatic macroinvertebrates has not been evaluated. Our aim was to document the short-term macroinvertebrate responses to an experimental disturbance that simulated the impacts of trampling by students in riffles within small headwater streams. We measured hydrologic variables, visually estimated substrate composition and sampled aquatic macroinvertebrates within control and experimental riffles in three agricultural headwater streams in central Ohio one day prior to experimental disturbance, immediately after disturbance and one day after disturbance. Hydrologic variables and substrate type did not differ daily or between riffle types. Macroinvertebrate abundance, percentage of Ephemeroptera Plecoptera Trichoptera and percentage of Leuctridae increased after experimental disturbance, while diversity, evenness, percentage of clingers and non-metric multidimensional scaling (NMS axis 1 site scores declined after disturbance. Macroinvertebrate diversity, percent clingers and NMS axis 1 site scores were lower in experimental riffles than control riffles. None of the macroinvertebrate response variables exhibited a significant interaction effect of day × riffle type that is indicative of an effect of the experimental disturbance. Our results suggest the one-time use of an undisturbed riffle within an agricultural headwater stream for an OE stream class is not likely to impact aquatic macroinvertebrates.

  19. Coexistence of fish species in a large lowland river: food niche partitioning between small-sized percids, cyprinids and sticklebacks in submersed macrophytes.

    Science.gov (United States)

    Dukowska, Małgorzata; Grzybkowska, Maria

    2014-01-01

    In the spring and summer of each year, large patches of submersed aquatic macrophytes overgrow the bottom of the alluvial Warta River downstream of a large dam reservoir owing to water management practices. Environmental variables, macroinvertebrates (zoobenthos and epiphytic fauna, zooplankton) and fish abundance and biomass were assessed at this biologically productive habitat to learn intraseasonal dynamics of food types, and their occurrence in the gut contents of small-sized roach, dace, perch, ruffe and three-spined stickleback. Gut fullness coefficient, niche breadth and niche overlap indicated how the fishes coexist in the macrophytes. Chironomidae dominated in the diet of the percids. However, ruffe consumed mostly benthic chironomids, while perch epiphytic chironomids and zooplankton. The diet of dace resembled that in fast flowing water although this rheophilic species occurred at unusual density there. The generalist roach displayed the lowest gut fullness coefficient values and widest niche breadth; consequently, intraspecific rather than interspecific competition decided the fate of roach. Three-spined stickleback differed from the other fishes by consuming epiphytic simuliids and fish eggs. The diet overlap between fishes reaching higher gut fullness coefficient values was rather low when the food associated with the submersed aquatic macrophytes was most abundant; this is congruent with the niche overlap hypothesis that maximal tolerable niche overlap can be higher in less intensely competitive conditions.

  20. 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.

  1. Ecological assessment of the Tajan river using feeding groups of benthic macroinvertebrates and biotic indices

    Directory of Open Access Journals (Sweden)

    M Sharifinia

    2012-06-01

    Full Text Available One of the best practical methods to understand ecological status of a water body and determine impacts of human intervention in reducing water quality is using benthic macroinvertebrates as assessment tools for monitoring their biological integrity and health. The Tajan River is one of the rivers of Caspian Southernsub-basin that drains the Caspian Sea. Macroinvertebrate samples were taken using Surber’s sampler (40 x 40 cm and 100µ mesh size in 45 day intervals with 3 replicates in each sampling site for a period of one year (May 2010 to May 2011. The collected organisms were preserved in 4% formalin solution and transferred to the laboratory for identification and counting. Six different functional feeding groups of macroinvertebrate e.g. Collector-gathering, Collector-filtering, Predator, Collector-gathering /Scraper, Predator/Collector-gathering and Scraper were determined. Feeding groups of Collector-gathering, Collector-filtering and Collector-gathering /Scraper were relatively dominant in comparison to other groups. Groups of Collector-filtering and Collector-gathering were dominant in slightly and heavily polluted stations, respectively. In this study population structure measures including abundance, EPT percent and the EPT and EPT/CHIR indics were mearsured. Species diversity, species richness were also determined using Shannon- Weiner, Margalef and Jacardindics. The minimum and maximum values of Hilsenhoff biotic index were observedin stations 1 (4.29 and 5 (5.57, respectively. Moreover, the highest and lowest values of BMWP/ASPT were observed in station 1 (4.51 and 5 (3.25, respectively. Evaluation of indicators revealed less water quality at stations 2, 3 and 5 which located at the lowermost of fish farms and effluent of factory. This reduction might be implicated to the effluents of water damps from fish farms running into the stream as diversity and total abundance (% of sociable macroinvertebrates decreased and that of

  2. An historical and geographic data set on the distribution of macroinvertebrates in Italian mountain lakes

    Directory of Open Access Journals (Sweden)

    Angela Boggero

    2017-11-01

    Full Text Available Macroinvertebrates play a key role in freshwater food webs, acting as major links between organic matter resources, primary consumers (such as bacteria, and secondary consumers (e.g.fish, amphibians, birds, and reptiles. In this paper we present a data set encompassing all geographic and historical data available on macroinvertebrates of the Italian mountain lakes from 1902 to 2016. The data set, divided per Italian mountain range (Alps and Apennines and administrative region, covers more than a century of studies of many foreign and Italian scientists. The data set includes 2372 records and shows macroinvertebrate occurrence data in 176 Alpine and in 13 Apennine lakes, of which 178 of natural origin, 5 reservoirs, and 6 artificially extended. The data set lists 605 taxa, updated on the basis of their current taxonomic position. Only 353 taxa are identified at species level, highlighting the still poorly investigated biodiversity of Italian mountain lake macroinvertebrates. Since they function as key elements to characterize lake ecological status, our data set emphasizes the huge taxonomic effort that still has to be undertaken to fully characterize these ecosystems. The data set is available in csv (comma-separated values format.

  3. A multicompartment approach--diatoms, macrophytes, benthic macroinvertebrates and fish--to assess the impact of toxic industrial releases on a small French river.

    Directory of Open Access Journals (Sweden)

    Manon Lainé

    Full Text Available The River Luzou flows through a sandy substrate in the South West of France. According to the results of two assessment surveys, the Water Agency appraised that this river may not achieve the good ecological status by 2015 as required by the Water Framework Directive (2000/60/EC. This ecosystem is impacted by industrial effluents (organic matter, metals and aromatic compounds. In order to assess and characterize the impact, this study aimed to combine a set of taxonomic and non-taxonomic metrics for diatoms, macrophytes, macroinvertebrates and fish along the up- to downstream gradient of the river. Diversity metrics, biological indices, biological and ecological traits were determined for the four biological quality elements (BQE. Various quantitative metrics (biomass estimates were also calculated for diatom communities. The results were compared to physicochemical analysis. Biological measurements were more informative than physicochemical analysis, in the context of the study. Biological responses indicated both the contamination of water and its intensity. Diversity metrics and biological indices strongly decreased with pollution for all BQE but diatoms. Convergent trait selection with pollution was observed among BQE: reproduction, colonization strategies, or trophic regime were clearly modified at impaired sites. Taxon size and relation to the substrate diverged among biological compartments. Multiple anthropogenic pollution calls for alternate assessment methods of rivers' health. Our study exemplifies the fact that, in the case of complex contaminations, biological indicators can be more informative for environmental risk, than a wide screening of contaminants by chemical analysis alone. The combination of diverse biological compartments provided a refined diagnostic about the nature (general mode of action and intensity of the contamination.

  4. A Multicompartment Approach - Diatoms, Macrophytes, Benthic Macroinvertebrates and Fish - To Assess the Impact of Toxic Industrial Releases on a Small French River

    Science.gov (United States)

    Lainé, Manon; Morin, Soizic; Tison-Rosebery, Juliette

    2014-01-01

    The River Luzou flows through a sandy substrate in the South West of France. According to the results of two assessment surveys, the Water Agency appraised that this river may not achieve the good ecological status by 2015 as required by the Water Framework Directive (2000/60/EC). This ecosystem is impacted by industrial effluents (organic matter, metals and aromatic compounds). In order to assess and characterize the impact, this study aimed to combine a set of taxonomic and non-taxonomic metrics for diatoms, macrophytes, macroinvertebrates and fish along the up- to downstream gradient of the river. Diversity metrics, biological indices, biological and ecological traits were determined for the four biological quality elements (BQE). Various quantitative metrics (biomass estimates) were also calculated for diatom communities. The results were compared to physicochemical analysis. Biological measurements were more informative than physicochemical analysis, in the context of the study. Biological responses indicated both the contamination of water and its intensity. Diversity metrics and biological indices strongly decreased with pollution for all BQE but diatoms. Convergent trait selection with pollution was observed among BQE: reproduction, colonization strategies, or trophic regime were clearly modified at impaired sites. Taxon size and relation to the substrate diverged among biological compartments. Multiple anthropogenic pollution calls for alternate assessment methods of rivers' health. Our study exemplifies the fact that, in the case of complex contaminations, biological indicators can be more informative for environmental risk, than a wide screening of contaminants by chemical analysis alone. The combination of diverse biological compartments provided a refined diagnostic about the nature (general mode of action) and intensity of the contamination. PMID:25019954

  5. Combined effects of hydrologic alteration and cyprinid fish in mediating biogeochemical processes in a Mediterranean stream.

    Science.gov (United States)

    Rubio-Gracia, Francesc; Almeida, David; Bonet, Berta; Casals, Frederic; Espinosa, Carmen; Flecker, Alexander S; García-Berthou, Emili; Martí, Eugènia; Tuulaikhuu, Baigal-Amar; Vila-Gispert, Anna; Zamora, Lluis; Guasch, Helena

    2017-12-01

    Flow regimes are important drivers of both stream community and biogeochemical processes. However, the interplay between community and biogeochemical responses under different flow regimes in streams is less understood. In this study, we investigated the structural and functional responses of periphyton and macroinvertebrates to different densities of the Mediterranean barbel (Barbus meridionalis, Cyprinidae) in two stream reaches differing in flow regime. The study was conducted in Llémena Stream, a small calcareous Mediterranean stream with high nutrient levels. We selected a reach with permanent flow (permanent reach) and another subjected to flow regulation (regulated reach) with periods of flow intermittency. At each reach, we used in situ cages to generate 3 levels of fish density. Cages with 10 barbels were used to simulate high fish density (>7indm -2 ); cages with open sides were used as controls (i.e. exposed to actual fish densities of each stream reach) thus having low fish density; and those with no fish were used to simulate the disappearance of fish that occurs with stream drying. Differences in fish density did not cause significant changes in periphyton biomass and macroinvertebrate density. However, phosphate uptake by periphyton was enhanced in treatments lacking fish in the regulated reach with intermittent flow but not in the permanent reach, suggesting that hydrologic alteration hampers the ability of biotic communities to compensate for the absence of fish. This study indicates that fish density can mediate the effects of anthropogenic alterations such as flow intermittence derived from hydrologic regulation on stream benthic communities and associated biogeochemical processes, at least in eutrophic streams. Copyright © 2017. Published by Elsevier B.V.

  6. Small nonnative fishes as predators of larval razorback suckers

    Science.gov (United States)

    Carpenter, J.; Mueller, G.A.

    2008-01-01

    The razorback sucker (Xyrauchen texanus), an endangered big-river fish of the Colorado River basin, has demonstrated no sustainable recruitment in 4 decades, despite presence of spawning adults and larvae. Lack of adequate recruitment has been attributed to several factors, including predation by nonnative fishes. Substantial funding and effort has been expended on mechanically removing nonnative game fishes, typically targeting large predators. As a result, abundance of larger predators has declined, but the abundance of small nonnative fishes has increased in some areas. We conducted laboratory experiments to determine if small nonnative fishes would consume larval razorback suckers. We tested adults of three small species (threadfin shad, Dorosoma petenense; red shiner, Cyprinella lutrensis; fathead minnow, Pimephales promelas) and juveniles of six larger species (common carp, Cyprinus carpio; yellow bullhead, Ameiurus natalis; channel catfish, Ictalurus punctatus; rainbow trout, Oncorhynchus mykiss; green sunfish, Lepomis cyanellus; bluegill, L. macrochirus). These nonnative fishes span a broad ecological range and are abundant within the historical range of the razorback sucker. All nine species fed on larval razorback suckers (total length, 9-16 mm). Our results suggest that predation by small nonnative fishes could be responsible for limiting recovery of this endangered species.

  7. 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.

  8. 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...... relatively small differences in temperature and oxygen may produce effects explaining ecological patterns, and depending on the taxon, either water temperature or oxygen saturation, without clear interacting effects, are important drivers of altitudinal limits....

  9. Agricultural Rivers at Risk: Dredging Results in a Loss of Macroinvertebrates. Preliminary Observations from the Narew Catchment, Poland

    Directory of Open Access Journals (Sweden)

    Mateusz Grygoruk

    2015-08-01

    Full Text Available Ecosystem deterioration in small lowland agricultural rivers that results from river dredging entails a significant threat to the appropriate ecohydrological conditions of these water bodies, expressed as homogenization of habitats and loss of biodiversity. Our study was aimed at a comparison of abundance and taxonomic structure of bottom-dwelling macroinvertebrates in dredged and non-dredged stretches of small lowland rivers and tributaries of the middle Narew River, namely: Czaplinianka, Turośnianka, Dąb, and Ślina. The experimental setup was (1 to collect samples of the bottom material from the river stretches that either persisted in a non-modified state (dredging was not done there in the last few years or had been subjected to river dredging in the year of sampling; and (2 to analyze the abundance and taxonomic structure of macroinvertebrates in the collected samples. The study revealed that at the high level of statistical significance (from p = 0.025 to p = 0.001, the total abundance of riverbed macroinvertebrates in the dredged stretches of the rivers analyzed was approximately 70% lower than in non-dredged areas. We state that the dredging of small rivers in agricultural landscapes seriously affects their ecological status by negatively influencing the concentrations and species richness of benthic macroinvertebrates.

  10. Methyl mercury concentrations in macroinvertebrates and fish from burned and undisturbed lakes on the Boreal Plain

    Energy Technology Data Exchange (ETDEWEB)

    Allen, E.W. [Alberta Univ., Edmonton, AB (Canada). Dept. of Biological Sciences; Prepas, E.E. [Alberta Univ., Edmonton, AB (Canada). Dept. of Biological Sciences; Lakehead Univ., Thunder Bay, ON (Canada). Faculty of Forest and the Forest Environment; Gabos, S.; Zhang, W. [Alberta Health and Wellness, Edmonton, AB (Canada); Strachan, W.M.J. [Environment Canada, Burlington, ON (Canada). National Water Research Inst.

    2005-09-01

    Methylmercury (MeHg) concentrations in macroinvertebrates and fish from 5 lakes in burned catchments in Alberta's Swan Hills region were compared with those from 5 reference lakes on the western Canadian Boreal Plain. The objective was to determine the effect of forest fire on the bioaccumulation of MeHg, a toxic pollutant. It was noted that lakes near the Alberta Special Waste Treatment Centre (ASWTC) have fish consumption advisories due to high mercury concentrations. In a separate comparison, MeHg concentrations in biota from a single lake were compared before and after a forest fire interrupted a prescribed timber harvest experiment. The affect of lake water chemistry, watershed characteristics, and trophic ecology on the bioaccumulation and biomagnification of MeHg in littoral food webs was also examined. The study area covered 2 ecoregions, the Boreal Foothills and the Boreal Mixedwood. Two years after the fire, MeHg concentrations in 5 of 6 aquatic taxa did not differ between burned and reference drainage basins in the Swan Hills. These results were in agreement with previous studies. Biomagnification of MeHg was negatively correlated with lake water chlorophyll 'a' concentration. Ecoregional variation in water chemistry seemed to influence MeHg concentrations in aquatic biota, which eluded comparisons of MeHg bioaccumulation between burned and reference drainage basins. MeHg concentrations in biota were negatively correlated with lake water pH, as well as with total phosphorous and dominant cation concentrations, all of which were higher in Mixedwood than in Foothills lakes. It was concluded that in the short-term, fire may lower MeHg concentrations in aquatic biota in a nutrient-rich setting by inducing an increase in lake productivity that dilutes MeHg at the base of the food web. 42 refs., 5 tabs., 7 figs.

  11. Technical efficiency of small-scale fishing households in Tanzanian ...

    African Journals Online (AJOL)

    This paper examines the technical efficiency of Tanzanian small-scale fishing households, based on data from two coastal villages located near Bagamoyo and Zanzibar, using a stochastic frontier model with technical inefficiency. The estimated mean technical efficiency of small-scale fishing households was 52%, showing ...

  12. 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).

  13. Design and testing of small scale fish meat bone separator useful for fish processing.

    Science.gov (United States)

    Ali Muhammed, M; Manjunatha, N; Murthy, K Venkatesh; Bhaskar, N

    2015-06-01

    The present study relates to the food processing machinery and, more specifically machine for producing boneless comminuted meat from raw fish fillet. This machine is of belt and drum type meat bone separator designed for small scale fish processing in a continuous mode. The basic principal involved in this machine is compression force. The electric geared motor consists of 1HP and the conveyor belt has a linear velocity of 19 to 22 m min(-1), which was sufficient to debone the fish effectively. During the meat bone separation trials an efficiency up to 75 % on dressed fish weight basis was observed and with a capacity to separate 70 kg h(-1) of meat from fish at the machine speed of 25 rpm. During the trials, it was demonstrated that there was no significant change in the proximate composition of comminuted fish meat when compared to unprocessed fish meat. This design has a greater emphasis on hygiene, provision for cleaning-in-place (CIP) and gives cost effective need and reliability for small scale industries to produce fish meat in turn used for their value added products.

  14. Diversity patterns of temporary wetland macroinvertebrate ...

    African Journals Online (AJOL)

    Although macroinvertebrates are potentially useful for assessing the condition of temporary wetlands, little is yet known about them. Macroinvertebrate assemblages were assessed in 138 temporary wetlands in the south-western Cape, recording 126 taxa. However, predicted richness estimates were all higher than the ...

  15. Development of a multimetric index based on macroinvertebrates for drainage ditch networks in agricultural areas.

    NARCIS (Netherlands)

    Verdonschot, R.C.M.; Keizer-Vlek, H.E.; Verdonschot, P.F.M.

    2012-01-01

    Drainage ditches are a prominent feature of many intensively managed agricultural areas. These small, shallow, line-shaped waterbodies could harbor a rich macroinvertebrate community, resembling that of natural small lentic ecosystems. Despite their high biodiversity potential, many ditch ecosystems

  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. Richness of littoral macroinvertebrate communities in mountain ponds from NW Spain: what factors does it depend on?

    Directory of Open Access Journals (Sweden)

    Francisco Garcia-Criado

    2012-01-01

    Full Text Available Recent researches have started to provide useful information on the littoral macroinvertebrates living in European mountain ponds. However, there is still uncertainty on the factors really shaping their communities. Understanding patterns of biodiversity in these systems is essential for conservation and management purposes. In this paper, we sampled littoral macroinvertebrates at 51 mountain ponds from a wide Spanish region (Castilla y León in order to define which of a set of environmental variables were responsible for differences in richness (genus level or above. One macroinvertebrate sample was collected at each pond (in late June or early July between 2004 and 2008 by kicking and sweeping following a multihabitat time-limited sampling. Twenty-four variables measured at 39 ponds were used to generate a predictive model by multiple linear regression. This model revealed number of habitats and fish stocking as the only significant variables, showing their relative importance against variables traditionally considered to influence richness in mountain ponds and lakes (for example, altitude and pond size. Furthermore, this model accurately predicted richness when tested on a new set of twelve ponds. Additional data analyses proved that neither altitude nor habitat type significantly influenced macroinvertebrate richness, while water permanence had a slight effect (the number of taxa was slightly lower in temporary than in permanent ponds.

  18. Ecological response of a multi-purpose river development project using macro-invertebrates richness and fish habitat value

    International Nuclear Information System (INIS)

    Pellaud, M.

    2007-05-01

    SYNERGIE project optimizer taking into account all the project poles. The system of interest is composed of a buffering reservoir of ca. 1 km 2 , a run-off-the- river dam, a hydro power-plant, and an artificial river ensuring longitudinal continuum. The primary part of the work consisted in an extensive literature review on system understanding, anthropic alterations and quality assessment / prediction tool available. The approach consisted of two levels (1) the general ecological considerations to be followed at the project reservoir scale and (2) the measure of the downstream ecological response through modeling. General ecological considerations at the reservoir scale were the implementation of an artificial river ensuring longitudinal connectivity, implementation of artificial ecotonal boosters and the allocation of a sanctuary zone with limited public access. The downstream measure of ecological integrity was based on the choice of three taxonomic groups of macroinvertebrates and four ecological guilds (groups) of fish. Mayflies (Ephemeroptera), stoneflies (Plecoptera) and caddisflies (Trichoptera) richness were predicted using simple hydrological and morphological covariates (i.e. substrate, current speed,...) coupled to system specific faunistic surveys. Bank, riffle, pool and midstream fish guilds habitat values were determined using existing methods. By using the simulation results of river development project scenarios as inputs, the ecological response (i.e. the measure of ecological integrity) was computed following the assumptions that high predicted macro-invertebrate richness and high guilds habitat values were linked to a high ecological integrity. An emphasis on the hydro peaking effect in relation with river morphology was performed on macroinvertebrates. They were found to respond well to hydrological and morphological changes induced by river development projects while the approach by fish habitat value encountered limitations in its applicability. Four

  19. Aquatic macroinvertebrates and water quality in Sandia Canyon

    International Nuclear Information System (INIS)

    Bennett, K.

    1994-05-01

    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

  20. 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. © 2016 John Wiley & Sons Ltd.

  1. Aquatic macroinvertebrates associated with Eichhornia azurea (Swartz Kunth and relationships with abiotic factors in marginal lentic ecosystems (São Paulo, Brazil

    Directory of Open Access Journals (Sweden)

    CV. Silva

    Full Text Available Marginal lakes are characterised by their having high biological diversity due to the presence of aquatic macrophytes in their coastal zones, providing habitats for refuge and food for animal community members. Among the fauna components associated with macrophytes, aquatic macroinvertebrates are important because they are an energy source for predators and fish. In six lakes and two different seasons (March and August 2009, the ecological attributes of aquatic macroinvertebrate community associated with Eichhornia azurea were compared and the controlling environmental factors were identified. Since the attributes of macroinvertebrate community are strictly associated with abiotic variables of each distinct habitat, our hypothesis was that each site associated with the same floating aquatic macrophyte (E. azurea should have a typical composition and density of organisms. We identified 50 taxa of macroinvertebrates, with greater taxa richness for aquatic insects (37 taxa divided into eight orders; the order Diptera being the most abundant in the two study periods. On the other hand, higher values of total taxa richness were recorded in August. Dissolved oxygen and pH presented the greatest number of significant positive correlations with the different taxa. The animals most frequently collected in the six lakes in March and August 2009 were Hirudinea, Oligochaeta, Hydrachnidae, Conchostraca, Ostracoda, Noteridae, Ceratopogonidae, Chironomidae, Culicidae, Caenidae, Pleidae, Aeshnidae, Libellulidae, Coenagrionidae and Nematoda. Only densities of Trichoptera, Ostracoda and Conchostraca presented the highest significant differences between lakes in both study periods and considering the composition of macroinvertebrates no significant differences were registered for macroinvertebrate composition.

  2. Macroinvertebrate variation in endorheic depression wetlands in ...

    African Journals Online (AJOL)

    Aquatic macroinvertebrates are rarely used in wetland assessments due to their variation. However, in terms of biodiversity, these invertebrates form an important component of wetland fauna. Spatial and temporal variation of macroinvertebrate assemblages in endorheic depressions (locally referred to as 'pans') in ...

  3. Australian experience of providing for fish passage at small instream structures

    Energy Technology Data Exchange (ETDEWEB)

    Lewis, B. [Forest Hill, Victoria (Australia)

    2006-07-01

    Various instream structures have been constructed in Australia as a result of increasing agricultural activities. However, even small structures such as culverts and stream gauging stations can restrict essential fish movements and result in the extinction of local fish species. This paper discussed methods of modifying and designing new structures to ensure adequate fish passage. It was suggested that instream structures can provide for fish passage through the provision of bridges, or through the use of low profile structures for small weirs. Recommendations for site-specific instream structures included an assessment of fish species, topography, flow characteristics and cost effectiveness. Solutions for reducing the impact of small instream barriers to fish movement were also discussed. Provision for fish passage is an important consideration for planners and designers of dams. Legislation is now in place to ensure a planning and approval process prior to the commencement of construction and operation. It was concluded that significant works are now being undertaken to restore fish migration pathways caused by barriers that restrict fish movement. However, monitoring is needed to ensure that designs operate effectively. 17 refs., 3 figs.

  4. Australian experience of providing for fish passage at small instream structures

    International Nuclear Information System (INIS)

    Lewis, B.

    2006-01-01

    Various instream structures have been constructed in Australia as a result of increasing agricultural activities. However, even small structures such as culverts and stream gauging stations can restrict essential fish movements and result in the extinction of local fish species. This paper discussed methods of modifying and designing new structures to ensure adequate fish passage. It was suggested that instream structures can provide for fish passage through the provision of bridges, or through the use of low profile structures for small weirs. Recommendations for site-specific instream structures included an assessment of fish species, topography, flow characteristics and cost effectiveness. Solutions for reducing the impact of small instream barriers to fish movement were also discussed. Provision for fish passage is an important consideration for planners and designers of dams. Legislation is now in place to ensure a planning and approval process prior to the commencement of construction and operation. It was concluded that significant works are now being undertaken to restore fish migration pathways caused by barriers that restrict fish movement. However, monitoring is needed to ensure that designs operate effectively. 17 refs., 3 figs

  5. Composition and dynamic of benthic macroinvertebrates community ...

    African Journals Online (AJOL)

    the purpose to analyze the taxonomic composition, the structure of benthic macroinvertebrates community and the composite ... differences relative to the spatial and temporal variation in the taxonomic composition. ... changes in the structure of macroinvertebrates community ... 2007) with an annual growth rate of 2.4% rely.

  6. Modeling Aquatic Macroinvertebrate Richness Using Landscape Attributes

    Directory of Open Access Journals (Sweden)

    Marcia S. Meixler

    2015-01-01

    Full Text Available We used a rapid, repeatable, and inexpensive geographic information system (GIS approach to predict aquatic macroinvertebrate family richness using the landscape attributes stream gradient, riparian forest cover, and water quality. Stream segments in the Allegheny River basin were classified into eight habitat classes using these three landscape attributes. Biological databases linking macroinvertebrate families with habitat classes were developed using life habits, feeding guilds, and water quality preferences and tolerances for each family. The biological databases provided a link between fauna and habitat enabling estimation of family composition in each habitat class and hence richness predictions for each stream segment. No difference was detected between field collected and modeled predictions of macroinvertebrate families in a paired t-test. Further, predicted stream gradient, riparian forest cover, and total phosphorus, total nitrogen, and suspended sediment classifications matched observed classifications much more often than by chance alone. High gradient streams with forested riparian zones and good water quality were predicted to have the greatest macroinvertebrate family richness and changes in water quality were predicted to have the greatest impact on richness. Our findings indicate that our model can provide meaningful landscape scale macroinvertebrate family richness predictions from widely available data for use in focusing conservation planning efforts.

  7. Work Element B: 157. Sampling in Fish-Bearing Reaches [Variation in Productivity in Headwater Reaches of the Wenatchee Subbasin], Final Report for PNW Research Station.

    Energy Technology Data Exchange (ETDEWEB)

    Polivka, Karl; Bennett, Rita L. [USDA Forest Service, Pacific Northwest Research Station, Wenatchee, WA

    2009-03-31

    We studied variation in productivity in headwater reaches of the Wenatchee subbasin for multiple field seasons with the objective that we could develop methods for monitoring headwater stream conditions at the subcatchment and stream levels, assign a landscape-scale context via the effects of geoclimatic parameters on biological productivity (macroinvertebrates and fish) and use this information to identify how variability in productivity measured in fishless headwaters is transmitted to fish communities in downstream habitats. In 2008, we addressed this final objective. In collaboration with the University of Alaska Fairbanks we found some broad differences in the production of aquatic macroinvertebrates and in fish abundance across categories that combine the effects of climate and management intensity within the subbasin (ecoregions). From a monitoring standpoint, production of benthic macroinvertebrates was not a good predictor of drifting macroinvertebrates and therefore might be a poor predictor of food resources available to fish. Indeed, there is occasionally a correlation between drifting macroinvertebrate abundance and fish abundance which suggests that headwater-derived resources are important. However, fish in the headwaters appeared to be strongly food-limited and there was no evidence that fishless headwaters provided a consistent subsidy to fish in reaches downstream. Fish abundance and population dynamics in first order headwaters may be linked with similar metrics further down the watershed. The relative strength of local dynamics and inputs into productivity may be constrained or augmented by large-scale biogeoclimatic control. Headwater streams are nested within watersheds, which are in turn nested within ecological subregions; thus, we hypothesized that local effects would not necessarily be mutually exclusive from large-scale influence. To test this we examined the density of primarily salmonid fishes at several spatial and temporal scales

  8. Macroinvertebrates and fishes in the part of the Danube flowing through the Iron Gate national park and possibilities of their protection under in situ and ex situ conditions

    Directory of Open Access Journals (Sweden)

    Simić Vladica M.

    2004-01-01

    Full Text Available Comparison of the results of later investigations of the Danube in the part flowing through in the Iron Gate (Đerdap National Park with those of research conducted earlier (20 to 40 years ago shows that changes have occurred in regard to the presence and especially the abundance of certain hydrobionts on this sector of the river, a finding that applies to all groups examined. The paper discusses the potential and results of conservation measures realized through both legal regulations and medium-term plans for the advancement of fishing in this region. In addition to in situ study during the period from 1999 to 2003, a large number of species (especially of macroinvertebrates and fish were also investigated under artificial conditions (in the Kragujevac Aquarium in order to gain a better understanding of their ecological characteristics, especially their sensitivity to various environmental stress factors. The presented results indicate that weight of specimens and success of culturing under ex situ conditions are correlated with their sensitivity under natural conditions.

  9. 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

  10. Integrating the fish embryo toxicity test as triad element for sediment toxicity assessment based on the water framework directive approach

    Energy Technology Data Exchange (ETDEWEB)

    Bartzke, Mariana [Dept. Aquatic Ecotoxicology, Goethe Univ. Frankfurt am Main (Germany); Gobio GmbH, Aarbergen/Kettenbach (Germany); Dept. Bioanalytical Ecotoxicology, Helmholtz Centre for Environmental Research, UFZ, Leipzig (Germany); Delov, Vera [Dept. Aquatic Ecotoxicology, Goethe Univ. Frankfurt am Main (Germany); Gobio GmbH, Aarbergen/Kettenbach (Germany); Ecotoxicology, Fraunhofer Inst. for Molecular Biology and Applied Ecology IME, Aachen (Germany); Stahlschmidt-Allner, Petra; Allner, Bernhard [Gobio GmbH, Aarbergen/Kettenbach (Germany); Oehlmann, Joerg [Dept. Aquatic Ecotoxicology, Goethe Univ. Frankfurt am Main (Germany)

    2010-04-15

    Purpose: The objective of this study was to complement analyses according to the European Union Water Framework Directive (WFD) with a sediment toxicity analysis as part of an integrated river assessment. To this end, Hessian water courses were analyzed using the sediment quality triad concept according to Chapman with chemical analyses, in situ effect evaluations, and ecotoxicological assessments. For the ecotoxicological assessment (fish embryo toxicity test with Danio rerio), a new evaluation scheme was developed, the fish teratogenicity index (FTI), that allows for a classification of sediments into ecological quality classes compliant to the WFD. Materials and methods sediment and macrozoobenthos samples were taken from tributaries of the rivers Fulda and Lahn. Sediments were characterized regarding particle size, carbon, heavy metals, and polyaromatic hydrocarbon content. Macroinvertebrate samples were taken via multi-habitat sampling. The fish embryo toxicity test with D. rerio was conducted as a contact assay on the basis of DIN 38415-6. Results and discussion The integrated assessment indicated a significant influence of heavy metals and carbon content on macroinvertebrate communities. The bioaccessibility of sediment pollutants were clearly demonstrated by the FTI, which showed a wide range of adverse effects. A significant linear relationship between metals and the FTI was detected. However, there was no statistically significant evidence that macroinvertebrate communities were affected by the hydromorphological quality clements at the sampling sites. Conclusions The new scheme for the assessment of fish embryo toxicity test was successfully applied. The results suggest that sediment compounds impact macroinvertebrate communities and early development of fish. It demonstrates that the quality of sediments should be evaluated on a routine basis as part of an integrated river assessment. (orig.)

  11. Macroinvertebrate communities associated with littoral zone habitats and the influence of environmental factors in Malilangwe Reservoir, Zimbabwe

    Directory of Open Access Journals (Sweden)

    Dalu T.

    2012-10-01

    Full Text Available The aim of our study was to investigate macroinvertebrate communities so as to understand factors and processes structuring macroinvertebrate communities in a small reservoir, Malilangwe reservoir over seven months (April to October. Sampling was performed by active sweep netting and searching soil sediments. Water temperature, conductivity, dissolved oxygen, pH, ammonia, nitrogen, phosphorus, chemical oxygen demand and macrophyte cover were determined. In total, forty-two macroinvertebrate families belonging to 10 orders were identified amongst 13 macrophyte species and sediments. Thiaridae and Physidae (Mollusca were the dominant and most abundant taxa (57.71% and there were followed by the Hemiptera (27.31%. High indices for sites 1 to 3 for the Simpsons index, the Shannon-Weaver index and evenness were recorded, while low indices were observed for sites 4 to 5, with significant differences being observed among the study site using the Kruskal-Wallis ANOVA test (p < 0.05. Redundancy Analysis revealed that among environmental factors, hydrologically linked parameters such as conductivity, water level and macrophyte cover had the strongest influence on macroinvertebrate distribution.

  12. Fishing Farmers or Farming Fishers? Fishing Typology of Inland Small-Scale Fishing Households and Fisheries Management in Singkarak Lake, West Sumatra, Indonesia

    Science.gov (United States)

    Yuerlita; Perret, Sylvain Roger; Shivakoti, Ganesh P.

    2013-07-01

    Technical and socio-economic characteristics are known to determine different types of fishers and their livelihood strategies. Faced with declining fish and water resources, small-scale fisheries engage into transformations in livelihood and fishing practices. The paper is an attempt to understand these changes and their socio-economic patterns, in the case of Singkarak Lake in West Sumatra, Indonesia. Based upon the hypothesis that riparian communities have diverse, complex yet structured and dynamic livelihood systems, the paper's main objective is to study, document and model the actual diversity in livelihood, practices and performance of inland small-scale fisheries along the Singkarak Lake, to picture how households are adapted to the situation, and propose an updated, workable model (typology) of those for policy. Principal component analysis and cluster analysis were used to develop a typology of fishing households. The results show that small-scale fishers can be classified into different types characterized by distinct livelihood strategies. Three household types are identified, namely "farming fishers" households (type I, 30 %), "fishing farmers" households (type II, 30 %), and "mainly fishers" households (type III, 40 %). There are significant differences among these groups in the number of boats owned, annual fishing income, agriculture income and farming experience. Type I consists of farming fishers, well equipped, with high fishing costs and income, yet with the lowest return on fishing assets. They are also landowners with farming income, showing the lowest return on land capital. Type II includes poor fishing farmers, landowners with higher farming income; they show the highest return on land asset. They have less fishing equipment, costs and income. Type III (mainly fishers) consists of poorer, younger fishers, with highest return on fishing assets and on fishing costs. They have little land, low farming income, and diversified livelihood

  13. Global multi-decadal ocean climate and small-pelagic fish population

    International Nuclear Information System (INIS)

    Tourre, Yves M; Lluch-Cota, Salvador E; White, Warren B

    2007-01-01

    Ocean climate, environmental and biological conditions vary on several spatio-temporal scales. Besides climate change associated with anthropogenic activity, there is growing evidence of a natural global multi-decadal climate signal in the ocean-atmosphere-biosphere climate system. The spatio-temporal evolution of this signal is thus analyzed during the 20th century and compared to the variability of small-pelagic fish landings. It is argued that the low-frequency global ocean environment and plankton ecosystems must be modified such that small-pelagic populations vary accordingly. A small-pelagic global index or fishing 'regime indicator series' (RIS) (i.e. a small-pelagic abundance indicator) is used. RIS is derived from fish landings data in the four main fishing areas in the Pacific and Atlantic oceans. Global RIS changes phase (from positive to negative values) when SST multi-decadal anomalies are out-of-phase between the eastern Pacific and southern Atlantic. RIS also displays maxima during the mid-30s to early-40s and the late-70s to early-80s when the multi-decadal signal was approximately changing phases (Tourre and White 2006 Geophys. Res. Lett. 33 L06716). It is recognized that other factors may modulate fish stocks, including anthropogenic predation. Nevertheless it is proposed that variable climate and environment, and the low-frequency 'global synchrony' of small-pelagic landings (Schwartzlose et al 1999 S. Afr. J. Mar. Sci. 21 289-347), could be associated with the multi-decadal changes in global ocean climate conditions

  14. Colonization of leaf litter of two aquatic macrophytes, Mayaca fluviatilis Aublet and Salvinia auriculata Aublet by aquatic macroinvertebrates in a tropical reservoir

    Directory of Open Access Journals (Sweden)

    Marcia Cristina de Paula

    2011-04-01

    Full Text Available Decomposition and colonization of S. auriculata and M. fluviatilis by macroinvertebrates were analyzed during 40 days to determine whether differences existed on colonization by aquatic macroinvertebrates of two macrophytes with distinct habits (submerged versus fluctuant. Leaf litter of S. auriculata and M. fluviatilis were incubated in 24 litter bags (12 of each species, in a small reservoir surrounded by a cerrado fragment with low level of anthropic impact. After 10, 20, 30 and 40 days, the litter bags were removed and aquatic macroinvertebrates community was analyzed. Two hundred twenty macroinvertebrates were associated with S. auriculata and 261 were associated with M. fluviatilis, identified in 24 taxa. Both macrophyte species were colonized mainly by macroinvertebrate predators. Ablabesmyia with predator and collector food mechanisms was present in all sampling. The data showed an expressive increase of abundance during the process of decomposition and a decrease at the end of the experiment, in both macrophytes. Cluster analysis permitted inference that the colonization of the leaf liter by macroinvertebrates was determinated by incubation time of leaf litter not by the habit of macrophytes (submerged or fluctuant.

  15. Performance of Very Small Robotic Fish Equipped with CMOS Camera

    Directory of Open Access Journals (Sweden)

    Yang Zhao

    2015-10-01

    Full Text Available Underwater robots are often used to investigate marine animals. Ideally, such robots should be in the shape of fish so that they can easily go unnoticed by aquatic animals. In addition, lacking a screw propeller, a robotic fish would be less likely to become entangled in algae and other plants. However, although such robots have been developed, their swimming speed is significantly lower than that of real fish. Since to carry out a survey of actual fish a robotic fish would be required to follow them, it is necessary to improve the performance of the propulsion system. In the present study, a small robotic fish (SAPPA was manufactured and its propulsive performance was evaluated. SAPPA was developed to swim in bodies of freshwater such as rivers, and was equipped with a small CMOS camera with a wide-angle lens in order to photograph live fish. The maximum swimming speed of the robot was determined to be 111 mm/s, and its turning radius was 125 mm. Its power consumption was as low as 1.82 W. During trials, SAPPA succeeded in recognizing a goldfish and capturing an image of it using its CMOS camera.

  16. Evaluation of Macroinvertebrate Data Based on Autoecological Information

    Directory of Open Access Journals (Sweden)

    Juhász I.

    2016-12-01

    Full Text Available Various data (biological, chemical, hydrological and morphological have been gathered within the frame of the monitoring of the Water Framework Directive from 2007 in Hungary. This data only used a status assessment of certain water bodies in Hungary. The macroinvertebrates indicate many environmental factors well; therefore, they are very useful in detecting changes in the status of an environment. The main aim in this research was to investigate changes in environmental variables and decide how these variables cause big changes in the macroinvertebrate fauna. The macroinvertebrate data was processed using the ASTERICS 4.0.4 program. The program calculated some important metrics (i.e., microhabitat distributions, longitudinal zonation, functional feeding guilds, etc.. These metrics were compared with the chemical and hydrological data. The main conclusion is that if we have enough of a frequency and quality of macroinvertebrate data, we can understand changes in the environment of an ecosystem.

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

    International Nuclear Information System (INIS)

    Thorp, J.H.; Bergey, E.A.

    1981-01-01

    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 m 2 ) 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 m 2 ) 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

  18. A Rapid Assessment of Macroinvertebrates Associated with Salvinia ...

    African Journals Online (AJOL)

    Salvinia molesta is an invasive species in the Okavango Delta. The plant forms monotypic covers in places where it occurs and thus affects macroinvertebrates diversity within them. Three habitats with low, moderate and heavy infestation by the weed were selected inside Moremi Game Reserve to study macroinvertebrates ...

  19. Ecological response of a multi-purpose river development project using macro-invertebrates richness and fish habitat value[Dissertation 3807

    Energy Technology Data Exchange (ETDEWEB)

    Pellaud, M.

    2007-05-15

    ) general SYNERGIE project optimizer taking into account all the project poles. The system of interest is composed of a buffering reservoir of ca. 1 km{sup 2}, a run-off-the- river dam, a hydro power-plant, and an artificial river ensuring longitudinal continuum. The primary part of the work consisted in an extensive literature review on system understanding, anthropic alterations and quality assessment / prediction tool available. The approach consisted of two levels (1) the general ecological considerations to be followed at the project reservoir scale and (2) the measure of the downstream ecological response through modeling. General ecological considerations at the reservoir scale were the implementation of an artificial river ensuring longitudinal connectivity, implementation of artificial ecotonal boosters and the allocation of a sanctuary zone with limited public access. The downstream measure of ecological integrity was based on the choice of three taxonomic groups of macroinvertebrates and four ecological guilds (groups) of fish. Mayflies (Ephemeroptera), stoneflies (Plecoptera) and caddisflies (Trichoptera) richness were predicted using simple hydrological and morphological covariates (i.e. substrate, current speed,...) coupled to system specific faunistic surveys. Bank, riffle, pool and midstream fish guilds habitat values were determined using existing methods. By using the simulation results of river development project scenarios as inputs, the ecological response (i.e. the measure of ecological integrity) was computed following the assumptions that high predicted macro-invertebrate richness and high guilds habitat values were linked to a high ecological integrity. An emphasis on the hydro peaking effect in relation with river morphology was performed on macroinvertebrates. They were found to respond well to hydrological and morphological changes induced by river development projects while the approach by fish habitat value encountered limitations in its

  20. Macroinvertebrate diversity in the karst Jadro River (Croatia

    Directory of Open Access Journals (Sweden)

    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.

  1. Effect of sewage oxidation pond effluent on macroinvertebrate ...

    African Journals Online (AJOL)

    The influence on aquatic macroinvertebrates of sewage oxidation pond effluent discharge was investigated in a tropical forest stream in Ile-Ife, Nigeria. A total of 858 individual macroinvertebrates were collected. They belong to 8 taxa which represent 5 orders. The number of taxa was low when compared to the findings in ...

  2. Qualitative Macroinvertebrate Assessment of Crouch Branch, June 1999

    International Nuclear Information System (INIS)

    Specht, W.L.

    1999-01-01

    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

  3. Small but powerful: top predator local extinction affects ecosystem structure and function in an intermittent stream.

    Science.gov (United States)

    Rodríguez-Lozano, Pablo; Verkaik, Iraima; Rieradevall, Maria; Prat, Narcís

    2015-01-01

    Top predator loss is a major global problem, with a current trend in biodiversity loss towards high trophic levels that modifies most ecosystems worldwide. Most research in this area is focused on large-bodied predators, despite the high extinction risk of small-bodied freshwater fish that often act as apex consumers. Consequently, it remains unknown if intermittent streams are affected by the consequences of top-predators' extirpations. The aim of our research was to determine how this global problem affects intermittent streams and, in particular, if the loss of a small-bodied top predator (1) leads to a 'mesopredator release', affects primary consumers and changes whole community structures, and (2) triggers a cascade effect modifying the ecosystem function. To address these questions, we studied the top-down effects of a small endangered fish species, Barbus meridionalis (the Mediterranean barbel), conducting an enclosure/exclosure mesocosm experiment in an intermittent stream where B. meridionalis became locally extinct following a wildfire. We found that top predator absence led to 'mesopredator release', and also to 'prey release' despite intraguild predation, which contrasts with traditional food web theory. In addition, B. meridionalis extirpation changed whole macroinvertebrate community composition and increased total macroinvertebrate density. Regarding ecosystem function, periphyton primary production decreased in apex consumer absence. In this study, the apex consumer was functionally irreplaceable; its local extinction led to the loss of an important functional role that resulted in major changes to the ecosystem's structure and function. This study evidences that intermittent streams can be affected by the consequences of apex consumers' extinctions, and that the loss of small-bodied top predators can lead to large ecosystem changes. We recommend the reintroduction of small-bodied apex consumers to systems where they have been extirpated, to restore

  4. Small but powerful: top predator local extinction affects ecosystem structure and function in an intermittent stream.

    Directory of Open Access Journals (Sweden)

    Pablo Rodríguez-Lozano

    Full Text Available Top predator loss is a major global problem, with a current trend in biodiversity loss towards high trophic levels that modifies most ecosystems worldwide. Most research in this area is focused on large-bodied predators, despite the high extinction risk of small-bodied freshwater fish that often act as apex consumers. Consequently, it remains unknown if intermittent streams are affected by the consequences of top-predators' extirpations. The aim of our research was to determine how this global problem affects intermittent streams and, in particular, if the loss of a small-bodied top predator (1 leads to a 'mesopredator release', affects primary consumers and changes whole community structures, and (2 triggers a cascade effect modifying the ecosystem function. To address these questions, we studied the top-down effects of a small endangered fish species, Barbus meridionalis (the Mediterranean barbel, conducting an enclosure/exclosure mesocosm experiment in an intermittent stream where B. meridionalis became locally extinct following a wildfire. We found that top predator absence led to 'mesopredator release', and also to 'prey release' despite intraguild predation, which contrasts with traditional food web theory. In addition, B. meridionalis extirpation changed whole macroinvertebrate community composition and increased total macroinvertebrate density. Regarding ecosystem function, periphyton primary production decreased in apex consumer absence. In this study, the apex consumer was functionally irreplaceable; its local extinction led to the loss of an important functional role that resulted in major changes to the ecosystem's structure and function. This study evidences that intermittent streams can be affected by the consequences of apex consumers' extinctions, and that the loss of small-bodied top predators can lead to large ecosystem changes. We recommend the reintroduction of small-bodied apex consumers to systems where they have been

  5. Advancing Toxicology Research Using In Vivo High Throughput Toxicology with Small Fish Models

    Science.gov (United States)

    Planchart, Antonio; Mattingly, Carolyn J.; Allen, David; Ceger, Patricia; Casey, Warren; Hinton, David; Kanungo, Jyotshna; Kullman, Seth W.; Tal, Tamara; Bondesson, Maria; Burgess, Shawn M.; Sullivan, Con; Kim, Carol; Behl, Mamta; Padilla, Stephanie; Reif, David M.; Tanguay, Robert L.; Hamm, Jon

    2017-01-01

    Summary Small freshwater fish models, especially zebrafish, offer advantages over traditional rodent models, including low maintenance and husbandry costs, high fecundity, genetic diversity, physiology similar to that of traditional biomedical models, and reduced animal welfare concerns. The Collaborative Workshop on Aquatic Models and 21st Century Toxicology was held at North Carolina State University on May 5-6, 2014, in Raleigh, North Carolina, USA. Participants discussed the ways in which small fish are being used as models to screen toxicants and understand mechanisms of toxicity. Workshop participants agreed that the lack of standardized protocols is an impediment to broader acceptance of these models, whereas development of standardized protocols, validation, and subsequent regulatory acceptance would facilitate greater usage. Given the advantages and increasing application of small fish models, there was widespread interest in follow-up workshops to review and discuss developments in their use. In this article, we summarize the recommendations formulated by workshop participants to enhance the utility of small fish species in toxicology studies, as well as many of the advances in the field of toxicology that resulted from using small fish species, including advances in developmental toxicology, cardiovascular toxicology, neurotoxicology, and immunotoxicology. We also review many emerging issues that will benefit from using small fish species, especially zebrafish, and new technologies that will enable using these organisms to yield results unprecedented in their information content to better understand how toxicants affect development and health. PMID:27328013

  6. Automatic feeder for small fish held in tanks

    Science.gov (United States)

    Joeris, Leonard S.

    1965-01-01

    The Northville (Michigan) Biological Station has been a center for study of the developmental morphology of coregonid fishes. This work requires the production of numerous individual series of lake herring, lake whitefish, and several species of chubs from parent fish of positively known identity. The offspring of individual pairs or groups of fish must be held in individual tanks from the time they hatch until they reach maturity. One of the important problems in this project has been the poor growth of most fish. Though some have grown well, their growth has been less than that of the same species in nature, and a few fish from each hatch have grown very slowly. Irregularity of feeding may contribute to the slow growth of laboratory fish. The hatchery caretaker feeds them several times during his 8-hour workday, but they must go without food during the remaining 16 hours. The high metabolic rate of small fish, however, appears to make them strongly inclined toward almost continual feeding. Belief that greater, more regular food consumption would result from a mechanical feeder providing a continuous supply of food over a longer period of the day led to development of the equipment described in this paper.

  7. Modeling small angle scattering data using FISH

    International Nuclear Information System (INIS)

    Elliott, T.; Buckely, C.E.

    2002-01-01

    Full text: Small angle neutron scattering (SANS) and small angle x-ray scattering (SAXS) are important techniques for the characterisation of samples on the nanometer scale. From the scattered intensity pattern information about the sample such as particle size distribution, concentration and particle interaction can be determined. Since the experimental data is in reciprocal space and information is needed about real space, modeling of the scattering data to obtain parameters is extremely important and several paradigms are available. The use of computer programs to analyze the data is imperative for a robust description of the sample to be obtained. This presentation gives an overview of the SAS process and describes the data-modeling program FISH, written by R. Heenan 1983-2000. The results of using FISH to obtain the particle size distribution of bubbles in the aluminum hydrogen system and other systems of interest are described. Copyright (2002) Australian X-ray Analytical Association Inc

  8. 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.

  9. [Species composition, diversity and density of small fishes in two different habitats in Niushan Lake].

    Science.gov (United States)

    Ye, Shao-Wen; Li, Zhong-Jie; Cao, Wen-Xuan

    2007-07-01

    This paper studied the spatial distribution of small fishes in a shallow macrophytic lake, Niushan Lake in spring 2003, and its relations with habitat heterogeneity. Based on the macrophyte cover condition, distance from lake shore and water depth, two representative habitat types in the lake were selected. Habitat A was near the shore with dense submersed macrophyte, while habitat B was far from the shore with sparse submersed macrophyte. Small fishes were sampled quantitatively by block net (180 m2), and their densities within the net area were estimated by multiple mark-recapture or Zippin's removal method. The results showed that there were some differences in species composition, biodiversity measurement, and estimated density of small fishes between the two habitats: 1) the catches in habitat A consisted of 14 small fish species from 5 families, among which, benthopelagic species Rhodeus ocellatus, Paracheilognathus imberbis and Pseudorasbora parva were considered as dominant species, while those in habitat B consisted of 9 small fish species from 3 families, among which, bottom species Rhinogobius giurinus and Micropercops swinhonis were dominant; 2) the Bray-Curtis index between the two small fish communities was 0.222, reflecting their low structure similarity, and no significant difference was observed between their rank/ abundance distributions, both of which belonged to log series distribution; 3) the total density of 9 major species in habitat A was 8.71 ind x m(-2), while that of 5 major species in habitat B was only 3.54 ind x m(-2). The fact that the spatial distribution of the small fishes differed with habitats might be related to their habitat need for escaping predators, feeding, and breeding, and thus, aquatic macrophyte habitat should be of significance in the rational exploitation of small fish resources as well as the conservation of fish resource diversity.

  10. Trait-based prediction of extinction risk of small-bodied freshwater fishes.

    Science.gov (United States)

    Kopf, R Keller; Shaw, Casey; Humphries, Paul

    2017-06-01

    Small body size is generally correlated with r-selected life-history traits, including early maturation, short-generation times, and rapid growth rates, that result in high population turnover and a reduced risk of extinction. Unlike other classes of vertebrates, however, small freshwater fishes appear to have an equal or greater risk of extinction than large fishes. We explored whether particular traits explain the International Union for Conservation of Nature (IUCN) Red List conservation status of small-bodied freshwater fishes from 4 temperate river basins: Murray-Darling, Australia; Danube, Europe; Mississippi-Missouri, North America; and the Rio Grande, North America. Twenty-three ecological and life-history traits were collated for all 171 freshwater fishes of ≤120 mm total length. We used generalized linear mixed-effects models to assess which combination of the 23 traits best explained whether a species was threatened or not threatened. We used the best models to predict the probability of 29 unclassified species being listed as threatened. With and without controlling for phylogeny at the family level, small body size-among small-bodied species-was the most influential trait correlated with threatened species listings. The k-folds cross-validation demonstrated that body size and a random effect structure that included family predicted the threat status with an accuracy of 78% (SE 0.5). We identified 10 species likely to be threatened that are not listed as such on the IUCN Red List. Small body size is not a trait that provides universal resistance to extinction, particularly for vertebrates inhabiting environments affected by extreme habitat loss and fragmentation. We hypothesize that this is because small-bodied species have smaller home ranges, lower dispersal capabilities, and heightened ecological specialization relative to larger vertebrates. Trait data and further model development are needed to predict the IUCN conservation status of the over 11

  11. Optimisation of the Monitoring Strategy of Macroinvertebrate Communities in the River Dender, in Relation to the EU Water Framework Directive

    Directory of Open Access Journals (Sweden)

    Tom P. D’heygere

    2002-01-01

    Full Text Available The Dender basin in Flanders (Belgium was used as a case study to implement the European Union (EU Water Framework Directive. During the last 5 years, ample research on pollution loads and ecological water quality has been done on the Dender River. In addition to biological sampling of macroinvertebrates and fish, automated measurement stations were also used to investigate the spatial-temporal variability of the physical-chemical water quality. This research revealed that the pollution of the Dender River is highly variable. The high nutrient loads result in severe algae blooms during summer, leading to very complex diurnal processes. In this paper, the monitoring strategy for the assessment of the biological water quality in the Dender basin has been reviewed in relation to the EU Water Framework Directive. For this, seasonal macroinvertebrate data were collected and assessed. General trends and hidden structures in these data were analysed by means of classification trees, using different inputs (seasons, river types, and subbasins. Validation of the results was obtained by applying statistical methods. Analysis about the presence and abundance of the macroinvertebrates revealed that there is a distinct difference between the biological water quality in the Dender stem river and its tributaries. There are also seasonal differences between the macroinvertebrate communities when the Dender and its tributaries are examined separately. An optimised monitoring strategy is proposed based on these results and the EU Water Framework Directive. This includes two monitoring campaigns in summer and winter every 3 years. Furthermore, a cyclic monitoring scheme was developed to minimise sampling efforts.

  12. The role of macroinvertebrates for conservation of freshwater systems.

    Science.gov (United States)

    Nieto, Carolina; Ovando, Ximena M C; Loyola, Rafael; Izquierdo, Andrea; Romero, Fátima; Molineri, Carlos; Rodríguez, José; Rueda Martín, Paola; Fernández, Hugo; Manzo, Verónica; Miranda, María José

    2017-07-01

    Freshwater ecosystems are the most threatened ecosystems worldwide. Argentinian-protected areas have been established mainly to protect vertebrates and plants in terrestrial ecosystems. In order to create a comprehensive biodiverse conservation plan, it is crucial to integrate both aquatic and terrestrial systems and to include macroinvertebrates. Here, we address this topic by proposing priority areas of conservation including invertebrates, aquatic ecosystems, and their connectivity and land uses. Northwest of Argentina. We modeled the ecological niches of different taxa of macroinvertebrates such as Coleoptera, Ephemeroptera, Hemiptera, Megaloptera, Lepidoptera, Odonata, Plecoptera, Trichoptera, Acari, and Mollusca. Based on these models, we analyzed the contribution of currently established protected areas in the conservation of the aquatic biodiversity and we propose a spatial prioritization taking into account possible conflict regarding different land uses. Our analysis units were the real watersheds, to which were added longitudinal connectivity up and down the rivers. A total of 132 species were modeled in the priority area analyses. The analysis 1 showed that only an insignificant percentage of the macroinvertebrates distribution is within the protected areas in the North West of Argentina. The analyses 2 and 3 recovered similar values of protection for the macroinvertebrate species. The upper part of Bermejo, Salí-Dulce, San Francisco, and the Upper part of Juramento basins were identified as priority areas of conservation. The aquatic ecosystems need special protection and 10% or even as much as 17% of land conservation is insufficient for species of macroinvertebrates. In turn the protected areas need to combine the aquatic and terrestrial systems and need to include macroinvertebrates as a key group to sustain the biodiversity. In many cases, the land uses are in conflict with the conservation of biodiversity; however, it is possible to apply the

  13. Are sugarcane leaf-detritus well colonized by aquatic macroinvertebrates?

    Directory of Open Access Journals (Sweden)

    Luciene Aparecida Leite-Rossi

    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.

  14. 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

    Directory of Open Access Journals (Sweden)

    Norma Luiza Würdig

    2011-02-01

    Full Text Available 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 at control plots. The families number was not statistically different (ANOVA, p > 0.05, but the total density of invertebrates, and the density of Ceratopogonidae were significant (ANOVA, p S. californicus, in this area, as the intensity of the cut held, did not affect considerably the aquatic macroinvertebrates. The results suggest that the small-scale extractivism in these regions carries little effect because the fauna of adjacent areas probably can quickly colonize the disturbed areas.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 at control plots. The families number was not statistically different (ANOVA, p > 0.05, but the total density of invertebrates, and the density of Ceratopogonidae were significant (ANOVA, p S. californicus, in this area, as the intensity of the cut held, did not affect considerably the aquatic macroinvertebrates. The results suggest that the small-scale extractivism in these regions carries little effect because the fauna of adjacent areas probably can quickly colonize the disturbed

  15. A Method for Measuring Fishing Effort by Small-Scale Fish Aggregating Device (FAD) Fishers from the Commonwealth of Dominica

    Science.gov (United States)

    Alvard, Michael; McGaffey, Ethan; Carlson, David

    2015-01-01

    We used global positioning system (GPS) technology and tracking analysis to measure fishing effort by marine, small-scale, fish aggregating device (FAD) fishers of the Commonwealth of Dominica. FADs are human-made structures designed to float on the surface of the water and attract fish. They are also prone to common pool resource problems. To…

  16. Macroinvertebrates associated with two submerged macrophytes ...

    African Journals Online (AJOL)

    Macroinvertebrates associated with two submerged macrophytes, Lagarosiphon ilicifolius and Vallisneria aethiopica , in the Sanyati Basin, Lake Kariba, Zimbabwe: effect of plant morphological complexity.

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

    Science.gov (United States)

    French, J. R. P.; 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.

  18. Using a Geospatial Model to Relate Fluvial Geomorphology to Macroinvertebrate Habitat in a Prairie River—Part 2: Matching Family-Level Indices to Geomorphological Response Units (GRUs

    Directory of Open Access Journals (Sweden)

    Anna Grace Nostbakken Meissner

    2016-03-01

    Full Text Available Many rivers are intensely managed due to anthropogenic influences such as dams, channelization, and water provision for municipalities, agriculture, and industry. With this growing pressure on fluvial systems comes a greater need to evaluate the state of their ecosystems. The purpose of this research is to use a geospatial model of the Qu’Appelle River in Saskatchewan to distinguish instream macroinvertebrate habitats at the family level. River geomorphology was assessed through the use of ArcGIS and digital elevation models; with these tools, the sinuosity, slope, fractal dimension, and stream width of the river were processed. Subsequently, Principal Component Analysis, a clustering technique, revealed areas with similar sets of geomorphological characteristics. These similar typology sequences were then grouped into geomorphological response units (GRUs, designated a color, and mapped into a geospatial model. Macroinvertebrate data was then incorporated to reveal several relationships to the model. For instance, certain GRUs contained more highly sensitive species and healthier diversity levels than others. Future possibilities for expanding on this project include incorporating stable isotope data to evaluate the food-web structure within the river basin. Although GRUs have been very successful in identifying fish habitats in other studies, the macroinvertebrates may be too sessile and their habitat too localized to be identified by such large river units. Units may need to be much shorter (250 m to better identify macroinvertebrate habitat.

  19. POP bioaccumulation in macroinvertebrates of alpine freshwater systems

    International Nuclear Information System (INIS)

    Bizzotto, E.C.; Villa, S.; Vighi, M.

    2009-01-01

    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.

  20. An evaluation of seasonal change in Benthic Macroinvertebrate community composition in the east branch of the Finniss River

    International Nuclear Information System (INIS)

    Edwards, C.

    2002-01-01

    Rum Jungle is an abandoned uranium-copper mine responsible for acid rock drainage into the surface waters of the intermittent East Branch and the channel of the Finniss Rivers. Prior to large-scale remediation in the mid 1980s, the East Branch was biologically dead for 8.5 km downstream to the confluence with the Finniss River, and suffered substantial ecological impairment for a further 15 km downstream. Recent studies suggest some recovery in fish diversity and abundance in the Finniss River, but only minor recovery in the macroinvertebrate fauna of the East Branch

  1. Variance in water chemistry parameters in isolated wetlands of Florida, USA, and relationships with macroinvertebrate and diatom community structure

    Science.gov (United States)

    Eighty small isolated wetlands throughout Florida were sampled in 2005 to explore within-site variability of water chemistry parameters and relate water chemistry to macroinvertebrate and diatom community structure. Three samples or measures of water were collected within each si...

  2. Seasonal comparison of aquatic macroinvertebrate assemblages in a flooded coastal freshwater marsh

    Science.gov (United States)

    Kang, Sung-Ryong; King, Sammy L.

    2013-01-01

    Marsh flooding and drying may be important factors affecting aquatic macroinvertebrate density and distribution in coastal freshwater marshes. Limited availability of water as a result of drying in emergent marsh may decrease density, taxonomic diversity, and taxa richness. The principal objectives of this study are to characterize the seasonal aquatic macroinvertebrate assemblage in a freshwater emergent marsh and compare aquatic macroinvertebrate species composition, density, and taxonomic diversity to that of freshwater marsh ponds. We hypothesize that 1) freshwater emergent marsh has lower seasonal density and taxonomic diversity compared to that of freshwater marsh ponds; and 2) freshwater emergent marsh has lower taxa richness than freshwater marsh ponds. Seasonal aquatic macroinvertebrate density in freshwater emergent marsh ranged from 0 organisms/m2 (summer 2009) to 91.1 ± 20.53 organisms/m2 (mean ± SE; spring 2009). Density in spring was higher than in all other seasons. Taxonomic diversity did not differ and there were no unique species in the freshwater emergent marsh. Our data only partially support our first hypothesis as aquatic macroinvertebrate density and taxonomic diversity between freshwater emergent marsh and ponds did not differ in spring, fall, and winter but ponds supported higher macroinvertebrate densities than freshwater emergent marsh during summer. However, our data did not support our second hypothesis as taxa richness between freshwater emergent marsh and ponds did not statistically differ.

  3. Environmental drivers of the benthic macroinvertebrates community in a hypersaline estuary (Northeastern Brazil

    Directory of Open Access Journals (Sweden)

    Carlinda Railly Ferreira Medeiros

    Full Text Available Abstract Introduction The estuarine community of benthic macroinvertebrates spatially varies in response to changes in environmental variables in these ecosystems. Understanding this variability helps our understanding the mechanisms structuring these communities. Aim Assess the structural aspects of the benthic macroinvertebrate community in a hypersaline estuary, and to relate to environmental variables that influence the community structure along the estuary. Methods The study was conducted at Tubarão river estuary in May 2015. We sampled two estuarine areas (upper and lower, and in each zone were sampled six points composed of two replicas, one sampled in sandy bottom and the other in muddy bottom. Samples of benthic macroinvertebrates and estuarine environmental variables were collected. Environmental drivers of the benthic macroinvertebrate community were determined by Distance-based Linear Models analysis. The contribution of individual species to the dissimilarity between the areas and substrate types were determined by analysis of the percentage of similarity. Results The composition of benthic macroinvertebrate community differed between the upper and lower areas, although it was similar between the muddy and sandy bottoms. The variation in the benthic community between areas was mainly related to the influence of salinity in the upper area. In the lower area, the variation of the macroinvertebrates was related to salinity, associated with other variables in the sandy (temperature, turbidity and dissolved oxygen and muddy (temperature, total dissolved solids and dissolved oxygen substrates. Taxa which contributed most to the dissimilarity between the upper and lower areas were Nereididae (17.89%, Anomalocardia brasiliana (15% and Cirratulidae (10.43%. Conclusions Salinity was the main driver of the structural aspects of the benthic macroinvertebrate community in the upper area of the estuary, although in the lower area a set of

  4. 77 FR 55755 - Small Business Size Standards: Agriculture, Forestry, Fishing, and Hunting

    Science.gov (United States)

    2012-09-11

    ... operation; and (3) within a specific small business definition or size standard established by SBA... SMALL BUSINESS ADMINISTRATION 13 CFR Part 121 RIN 3245-AG43 Small Business Size Standards: Agriculture, Forestry, Fishing, and Hunting AGENCY: U.S. Small Business Administration. ACTION: Proposed rule...

  5. Water quality and the composition of fish and macroinvertebrate communities in the Devils and Pecos Rivers within and upstream from the Amistad National Recreation Area, Texas, 2005-7

    Science.gov (United States)

    Moring, J. Bruce

    2012-01-01

    To gain a better understanding of the water quality and status of fish and macroinvertebrate communities, the U.S. Geological Survey, in cooperation with the National Park Service and Amistad National Recreation Area, completed a reconnaissance-level survey of the water quality and fish and macroinvertebrate communities in the Devils and Pecos Rivers in and upstream from the Amistad National Recreation Area in southwest Texas during 2005–7. Water-quality conditions during the spring and summer months of 2005 in the Devils and Pecos Rivers were assessed at locations just upstream from the Amistad National Recreation Area, and the composition of fish and macroinvertebrate communities were assessed during 2006 and 2007 in and upstream from the Amistad National Recreation Area and Amistad Reservoir. Water-quality samples were collected at one site on both the Devils and Pecos Rivers. Fish and macroinvertebrates were collected at the water-quality sampling site on each river and at three additional sites on each river. The water-quality constituents of primary concern were total dissolved solids, chloride, sulfate, ammonia plus organic nitrogen, nitrate plus nitrite, orthophosphate, phosphorus, selenium, and selected pesticides. During the spring and summer of 2005, the concentrations of total dissolved solids ranged from 208 to 232 milligrams per liter (mg/L) in samples from the Devils River compared to 1,460 to 2,390 mg/L in samples from the Pecos River. Total dissolved solid concentrations measured in samples collected from the Devils River and Pecos River did not exceed the proposed State of Texas water-quality standard applicable for the segments of each river where samples were collected. During the spring and summer of 2005, chloride concentrations measured in samples collected in 2005 from the Devils River ranged from 11.6 to 12.9 mg/L, compared to chloride concentrations measured in samples collected from the Pecos River, which ranged from 519 to 879 mg

  6. Longitudinal patterns in fish and macrozoobenthos assemblages reflect degradation of water quality and physical habitat in the Bílina river basin

    Czech Academy of Sciences Publication Activity Database

    Jurajda, Pavel; Adámek, Zdeněk; Janáč, Michal; Valová, Zdenka

    2010-01-01

    Roč. 55, č. 3 (2010), s. 123-136 ISSN 1212-1819 R&D Projects: GA MŠk LC522 Institutional research plan: CEZ:AV0Z60930519 Keywords : fish community * macroinvertebrates * pollution * channelization * Elbe basin Subject RIV: GL - Fishing Impact factor: 1.190, year: 2010 http://www.agriculturejournals.cz/publicFiles/17674.pdf

  7. A case study of life cycle impacts of small-scale fishing techniques in Thailand

    DEFF Research Database (Denmark)

    Verones, Francesca; Bolowich, Alya F.; Ebata, Keigo

    2017-01-01

    Fish provides an important source of protein, especially in developing countries, and the amounts of fish consumed are increasing worldwide (mostly from aquaculture). More than half of all marine fish are caught by small-scale fishery operations. However, no life cycle assessment (LCA) of small...... inventories for three different seasons (northeast monsoon, southwest monsoon and pre-monsoon), since the time spent on the water and catch varied significantly between the seasons. Our results showed the largest impacts from artisanal fishing operations affect climate change, human toxicity, and fossil...... and metal depletion. Our results are, in terms of global warming potential, comparable with other artisanal fisheries. Between different fishing operations, impacts vary between a factor of 2 (for land transformation impacts) and up to a factor of more than 20 (fossil fuel depletion and marine...

  8. The influence of urbanisation on macroinvertebrate biodiversity in constructed stormwater wetlands.

    Science.gov (United States)

    Mackintosh, Teresa J; Davis, Jenny A; Thompson, Ross M

    2015-12-01

    The construction of wetlands in urban environments is primarily carried out to assist in the removal of contaminants from wastewaters; however, these wetlands have the added benefit of providing habitat for aquatic invertebrates, fish and waterbirds. Stormwater quantity and quality is directly related to impervious area (roads, sealed areas, roofs) in the catchment. As a consequence, it would be expected that impervious area would be related to contaminant load and biodiversity in receiving waters such as urban wetlands. This study aimed to establish whether the degree of urbanisation and its associated changes to stormwater runoff affected macroinvertebrate richness and abundance within constructed wetlands. Urban wetlands in Melbourne's west and south east were sampled along a gradient of urbanisation. There was a significant negative relationship between total imperviousness (TI) and the abundance of aquatic invertebrates detected for sites in the west, but not in the south east. However macroinvertebrate communities were relatively homogenous both within and between all study wetlands. Chironomidae (non-biting midges) was the most abundant family recorded at the majority of sites. Chironomids are able to tolerate a wide array of environmental conditions, including eutrophic and anoxic conditions. Their prevalence suggests that water quality is impaired in these systems, regardless of degree of urbanisation, although the causal mechanism is unclear. These results show some dependency between receiving wetland condition and the degree of urbanisation of the catchment, but suggest that other factors may be as important in determining the value of urban wetlands as habitat for wildlife. Copyright © 2015 Elsevier B.V. All rights reserved.

  9. 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),...

  10. Agricultural Rivers at Risk: Dredging Results in a Loss of Macroinvertebrates. Preliminary Observations from the Narew Catchment, Poland

    OpenAIRE

    Mateusz Grygoruk; Magdalena Frąk; Aron Chmielewski

    2015-01-01

    Ecosystem deterioration in small lowland agricultural rivers that results from river dredging entails a significant threat to the appropriate ecohydrological conditions of these water bodies, expressed as homogenization of habitats and loss of biodiversity. Our study was aimed at a comparison of abundance and taxonomic structure of bottom-dwelling macroinvertebrates in dredged and non-dredged stretches of small lowland rivers and tributaries of the middle Narew River, namely: Czaplinianka, Tu...

  11. 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

  12. Simulating mechanisms for dispersal, production and stranding of small forage fish in temporary wetland habitats

    Science.gov (United States)

    Yurek, Simeon; DeAngelis, Donald L.; Trexler, Joel C.; Jopp, Fred; Donalson, Douglas D.

    2013-01-01

    Movement strategies of small forage fish (wetland habitats affect their overall population growth and biomass concentrations, i.e., availability to predators. These fish are often the key energy link between primary producers and top predators, such as wading birds, which require high concentrations of stranded fish in accessible depths. Expansion and contraction of seasonal wetlands induce a sequential alternation between rapid biomass growth and concentration, creating the conditions for local stranding of small fish as they move in response to varying water levels. To better understand how landscape topography, hydrology, and fish behavior interact to create high densities of stranded fish, we first simulated population dynamics of small fish, within a dynamic food web, with different traits for movement strategy and growth rate, across an artificial, spatially explicit, heterogeneous, two-dimensional marsh slough landscape, using hydrologic variability as the driver for movement. Model output showed that fish with the highest tendency to invade newly flooded marsh areas built up the largest populations over long time periods with stable hydrologic patterns. A higher probability to become stranded had negative effects on long-term population size, and offset the contribution of that species to stranded biomass. The model was next applied to the topography of a 10 km × 10 km area of Everglades landscape. The details of the topography were highly important in channeling fish movements and creating spatiotemporal patterns of fish movement and stranding. This output provides data that can be compared in the future with observed locations of fish biomass concentrations, or such surrogates as phosphorus ‘hotspots’ in the marsh.

  13. Macroinvertebrate distribution and aquatic ecology in the Ruoergai (Zoige) Wetland, the Yellow River source region

    Science.gov (United States)

    Zhao, Na; Xu, Mengzhen; Li, Zhiwei; Wang, Zhaoyin; Zhou, Hanmi

    2017-09-01

    The Ruoergai (Zoige) Wetland, the largest plateau peatland in the world, is located in the Yellow River source region. The discharge of the Yellow River increases greatly after flowing through the Ruoergai Wetland. The aquatic ecosystem of the Ruoergai Wetland is crucial to the whole Yellow River basin. The Ruoergai wetland has three main kinds of water bodies: rivers, oxbow lakes, and marsh wetlands. In this study, macroinvertebrates were used as indicators to assess the aquatic ecological status because their assemblage structures indicate long-term changes in environments with high sensitivity. Field investigations were conducted in July, 2012 and in July, 2013. A total of 72 taxa of macroinvertebrates belonging to 35 families and 67 genera were sampled and identified. Insecta was the dominant group in the Ruoergai Basin. The alpha diversity of macroinvertebrates at any single sampling site was low, while the alpha diversity on a basin-wide scale was much higher. Macroinvertebrate assemblages in rivers, oxbow lakes, and marsh wetlands differ markedly. Hydrological connectivity was a primary factor causing the variance of the bio-community. The river channels had the highest alpha diversity of macroinvertebrates, followed by marsh wetlands and oxbow lakes. The density and biomass of Gastropoda, collector filterers, and scrapers increased from rivers to oxbow lakes and then to marsh wetlands. The river ecology was particular in the Ruoergai Wetland with the high beta diversity of macroinvertebrates, the low alpha diversity of macroinvertebrates, and the low taxa richness, density, and biomass of EPT (Ephemeroptera, Plecoptera, Trichoptera). To maintain high alpha diversity of macroinvertebrates macroinvertebrates in the Ruoergai Wetland, moderate connectivity of oxbow lakes and marsh wetlands with rivers and measures to control headwater erosion are both crucial.

  14. Macroinvertebrate response to acid mine drainage: community metrics and on-line behavioural toxicity bioassay

    International Nuclear Information System (INIS)

    Gerhardt, A.; Janssens de Bisthoven, L.; Soares, A.M.V.M.

    2004-01-01

    The hypothesis is tested that toxicity of acid mine drainage can be detected by a selection of existing macroinvertebrate community and bioindicator metrices supplemented by toxicity tests with the local mosquitofish Gambusia holbrooki Girard and the shrimp Atyaephyra desmaresti Millet. The behavioural responses of A. desmaresti to acid mine drainage were recorded in the Multispecies Freshwater Biomonitor[reg], based on behaviour and survival as parameters. Bioassessment methods were based on community diversity, structure, function, and bioindicators and supplemented by chemical analysis (temperature, pH, metals). The Biological Monitoring Working Party adapted for the Iberian Peninsula, the number of predators (Coleoptera, Hemiptera) and the number of Ephemeroptera and Trichoptera taxa differentiated the sites well. The on-line toxicity test revealed pH-dependent acute toxicity of the acid mine drainage for the shrimp (LC 50 -48 h: pH-AMD=5.8) and a pH- dependent decrease in locomotory activity with the lowest-observed-response-times (LORTs) within 5 h of exposure. Shrimp were more sensitive to acid mine drainage than fish (LC 50 -48 h: pH-AMD=4.9). A new multimetric index combining toxicity testing and bioassessment methods is proposed. - Toxicity of acid mine drainage was evaluated by macroinvertebrate bioassessment and a new on-line rapid behavioural toxicity test with Atyaephyra desmaresti (Crustacea)

  15. Macroinvertebrate response to acid mine drainage: community metrics and on-line behavioural toxicity bioassay

    Energy Technology Data Exchange (ETDEWEB)

    Gerhardt, A.; Janssens de Bisthoven, L.; Soares, A.M.V.M

    2004-07-01

    The hypothesis is tested that toxicity of acid mine drainage can be detected by a selection of existing macroinvertebrate community and bioindicator metrices supplemented by toxicity tests with the local mosquitofish Gambusia holbrooki Girard and the shrimp Atyaephyra desmaresti Millet. The behavioural responses of A. desmaresti to acid mine drainage were recorded in the Multispecies Freshwater Biomonitor[reg], based on behaviour and survival as parameters. Bioassessment methods were based on community diversity, structure, function, and bioindicators and supplemented by chemical analysis (temperature, pH, metals). The Biological Monitoring Working Party adapted for the Iberian Peninsula, the number of predators (Coleoptera, Hemiptera) and the number of Ephemeroptera and Trichoptera taxa differentiated the sites well. The on-line toxicity test revealed pH-dependent acute toxicity of the acid mine drainage for the shrimp (LC{sub 50}-48 h: pH-AMD=5.8) and a pH- dependent decrease in locomotory activity with the lowest-observed-response-times (LORTs) within 5 h of exposure. Shrimp were more sensitive to acid mine drainage than fish (LC{sub 50}-48 h: pH-AMD=4.9). A new multimetric index combining toxicity testing and bioassessment methods is proposed. - Toxicity of acid mine drainage was evaluated by macroinvertebrate bioassessment and a new on-line rapid behavioural toxicity test with Atyaephyra desmaresti (Crustacea)

  16. Life cycle ecophysiology of small pelagic fish and climate-driven changes in populations

    Science.gov (United States)

    Peck, Myron A.; Reglero, Patricia; Takahashi, Motomitsu; Catalán, Ignacio A.

    2013-09-01

    Due to their population characteristics and trophodynamic role, small pelagic fishes are excellent bio-indicators of climate-driven changes in marine systems world-wide. We argue that making robust projections of future changes in the productivity and distribution of small pelagics will require a cause-and-effect understanding of historical changes based upon physiological principles. Here, we reviewed the ecophysiology of small pelagic (clupeiform) fishes including a matrix of abiotic and biotic extrinsic factors (e.g., temperature, salinity, light, and prey characteristics) and stage-specific vital rates: (1) adult spawning, (2) survival and development of eggs and yolk sac larvae, and (3) feeding and growth of larvae, post-larvae and juveniles. Emphasis was placed on species inhabiting Northwest Pacific and Northeast Atlantic (European) waters for which summary papers are particularly scarce compared to anchovy and sardine in upwelling systems. Our review revealed that thermal niches (optimal and sub-optimal ranges in temperatures) were species- and stage-specific but that temperature effects only partly explained observed changes in the distribution and/or productivity of populations in the Northwest Pacific and Northeast Atlantic; changes in temperature may be necessary but not sufficient to induce population-level shifts. Prey availability during the late larval and early juvenile period was a common, density-dependent mechanism linked to fluctuations in populations but recruitment mechanisms were system-specific suggesting that generalizations of climate drivers across systems should be avoided. We identified gaps in knowledge regarding basic elements of the growth physiology of each life stage that will require additional field and laboratory study. Avenues of research are recommended that will aid the development of models that provide more robust, physiological-based projections of the population dynamics of these and other small pelagic fish. In our

  17. Consequences of the size structure of fish populations for their effects on a generalist avian predator.

    Science.gov (United States)

    Kloskowski, Janusz

    2011-06-01

    Size-structured interspecific interactions can shift between predation and competition, depending on ontogenetic changes in size relationships. I examined the effects of common carp (Cyprinus carpio), an omnivorous fish, on the reproductive success of the red-necked grebe (Podiceps grisegena), an avian gape-limited predator, along a fish size gradient created by stocking distinct age-cohorts in seminatural ponds. Young-of-the-year (0+) carp were an essential food source for young grebes. Only adult birds were able to consume 1-year-old (1+) fish, while 2-year-old (2+) fish attained a size refuge from grebes. Amphibian larvae were the principal alternative prey to fish, followed by macroinvertebrates, but the abundance of both dramatically decreased along the carp size gradient. Fledging success was 2.8 times greater in ponds with 0+ versus 1+ carp; in ponds with 1+ carp, chicks received on average 2.6-3 times less prey biomass from their parents, and over 1/3 of broods suffered total failure. Breeding birds avoided settling on 2+ ponds. These results show that changes in prey fish size structure can account for shifts from positive trophic effects on the avian predator to a negative impact on the predator's alternative resources. However, competition did not fully explain the decrease in grebe food resources in the presence of large fish, as carp and grebes overlapped little in diet. In experimental cages, 1+ carp totally eliminated young larvae of amphibians palatable to fish. In field conditions, breeding adults of palatable taxa avoided ponds with 1+ and older carp. Non-trophic interactions such as habitat selection by amphibians or macroinvertebrates to avoid large fish may provide an indirect mechanism strengthening the adverse bottom-up effects of fish on birds.

  18. Biogeographic characterization of fish and benthic communities, St Croix, US Virgin Islands 2010-10-18 to 2011-11-10 (NODC Accession 0125270)

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — The intent of this work is five fold: 1) To spatially characterize and monitor the distribution, abundance, and size of both reef fishes and macro-invertebrates...

  19. Fish catch composition of selected small scale fishing gears used in the Bonny River, Rivers State, Nigeria

    Directory of Open Access Journals (Sweden)

    Olaniyi Alaba Olopade

    2017-04-01

    Full Text Available Fish catch composition of some selected small scale fishing gears (gill net, cast net, beach seine and long line were investigated in Bonny River, Rivers State, Nigeria from August 2014 to January 2015. A total number of 25 fish species from 18 families were recorded during the study. The Mugilidae with only one species constituted the dominant family while Cichlidae, Lutjanidae, Clupeidae, had three species and Scianidae had two species of fish caught and the remaining families had one species each. Mugil cephalus constituted 28.48% of the total catches followed by C. nigrodigitatus (22.48%. In the dry season M. cephalus forms the major component landings (32.65%, followed by C. nigrodigitatus (26.53% and S. galilaeus (12.24% while in the wet season M. cephalus (31.06%, C. nigrodigitatus (18.63% and T. zillii (11.80% were the dominant fish species. Cast net was the most efficient fishing gear while gill net was the least efficient. The comparison analysis between the wet and dry seasons using t-test showed no significant difference between dry and wet seasons (t = 0.092, P > 0.05.

  20. Effects of small hydropower plants on mercury concentrations in fish.

    Science.gov (United States)

    Cebalho, Elaine C; Díez, Sergi; Dos Santos Filho, Manoel; Muniz, Claumir Cesar; Lázaro, Wilkinson; Malm, Olaf; Ignácio, Aurea R A

    2017-10-01

    Although the impacts of large dams on freshwater biota are relatively well known, the effects of small hydropower plants (SHP) are not well investigated. In this work, we studied if mercury (Hg) concentrations in fish rise in two tropical SHP reservoirs, and whether similar effects take place during impoundment. Total Hg concentrations in several fish species were determined at two SHP in the Upper Guaporé River basin floodplain, Brazil. In total, 185 specimens were analysed for Hg content in dorsal muscle and none of them reported levels above the safety limit (500 μg kg -1 ) for fish consumption recommended by the World Health Organisation (WHO). The highest levels of Hg (231 and 447 μg kg -1 ) were found in carnivorous species in both reservoirs. Mercury increased as a function of standard length in most of the fish populations in the reservoirs, and higher Hg concentrations were found in fish at the reservoir compared with fish downstream. The high dissolved oxygen concentrations and high transparency of the water column (i.e. oligotrophic reservoir) together with the absence of thermal stratification may explain low Hg methylation and low MeHg levels found in fish after flooding. Overall, according to limnological characteristics of water, we may hypothesise that reservoir conditions are not favourable to high net Hg methylation.

  1. 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. Copyright © 2016 Elsevier Ltd. All rights reserved.

  2. Comparison of the abiotic preferences of macroinvertebrates in tropical river basins.

    Directory of Open Access Journals (Sweden)

    Gert Everaert

    Full Text Available We assessed and compared abiotic preferences of aquatic macroinvertebrates in three river basins located in Ecuador, Ethiopia and Vietnam. Upon using logistic regression models we analyzed the relationship between the probability of occurrence of five macroinvertebrate families, ranging from pollution tolerant to pollution sensitive, (Chironomidae, Baetidae, Hydroptilidae, Libellulidae and Leptophlebiidae and physical-chemical water quality conditions. Within the investigated physical-chemical ranges, nine out of twenty-five interaction effects were significant. Our analyses suggested river basin dependent associations between the macroinvertebrate families and the corresponding physical-chemical conditions. It was found that pollution tolerant families showed no clear abiotic preference and occurred at most sampling locations, i.e. Chironomidae were present in 91%, 84% and 93% of the samples taken in Ecuador, Ethiopia and Vietnam. Pollution sensitive families were strongly associated with dissolved oxygen and stream velocity, e.g. Leptophlebiidae were only present in 48%, 2% and 18% of the samples in Ecuador, Ethiopia and Vietnam. Despite some limitations in the study design, we concluded that associations between macroinvertebrates and abiotic conditions can be river basin-specific and hence are not automatically transferable across river basins in the tropics.

  3. Biodiversity of benthic macroinvertebrates in Air Terjun Asahan, Asahan, Melaka, Malaysia

    Science.gov (United States)

    Nurhafizah-Azwa, S.; Ahmad A., K.

    2016-11-01

    A study on benthic macroinvertebrate diversity was conducted at Air Terjun Asahan, Asahan, Melaka. Five stations were selected with distance intervals of approximately 500 metres. Three replicates of benthic macroinvertebrate and water samples were taken. Results classified Air Terjun Asahan in class II, which indicated good water quality based on WQI recommended by the Department of Environment. A total of 1 phylum, 2 classes, 6 order, 30 families, and 2183 individuals were successfully sampled and recorded. The analysis showed that the average value of Shannon Diversity Index, H' (2.19), Pielou Evenness Index, J' (0.30), and Margaleff Richness Index, DMG (3.77) described that Air Terjun Asahan was in moderate condition and the distribution of macroinvertebrates was uniform between stations. Correlation test showed that the WQI had a strong relationship with the diversity indices involved. BMWP, and FBI showed that Air Terjun Asahan was in good water quality. CCA test was conducted to show environmental factors towards benthic macroinvertebrate distribution. The presence of Leptophlebiidae, Baetidae, Heptageniidae and Chironomidae with high abundance of the families showed the potential as biological indicators of a clean ecosystem.

  4. Hankin and Reeves' approach to estimating fish abundance in small streams: limitations and alternatives

    Science.gov (United States)

    William L. Thompson

    2003-01-01

    Hankin and Reeves' (1988) approach to estimating fish abundance in small streams has been applied in stream fish studies across North America. However, their population estimator relies on two key assumptions: (1) removal estimates are equal to the true numbers of fish, and (2) removal estimates are highly correlated with snorkel counts within a subset of sampled...

  5. Rapid changes in small fish mercury concentrations in estuarine wetlands: Implications for wildlife risk and monitoring programs

    Science.gov (United States)

    Eagles-Smith, Collin A.; Ackerman, Joshua T.

    2009-01-01

    Small fish are commonly used to assess mercury (Hg) risk to wildlife and monitor Hg in wetlands. However, limited research has evaluated short-term Hg variability in small fish, which can have important implications for monitoring programs and risk assessment. We conducted a time-series study of Hg concentrations in two small fish species representing benthic (longjaw mudsuckers [Gillichthys mirabilis]) and pelagic (threespine sticklebacks [Gasterosteus aculeatus]) food-webs within three wetland habitats in San Francisco Bay Estuary. We simultaneously monitored prey deliveries, nest initiation, and chick hatching dates of breeding Forster's terns (Sterna forsteri), the most abundant nesting piscivore in the region. Mudsuckers and sticklebacks were the predominant prey fish, comprising 36% and 25% of tern diet, and Hg concentrations averaged (geometric mean ?? SE, ??g/g dw) 0.44 ?? 0.01 and 0.68 ?? 0.03, respectively. Fish Hg concentrations varied substantially over time following a quadratic form in both species, increasing 40% between March and May then decreasing 40% between May and July. Importantly, Forster's terns initiated 68% of nests and 31% of chicks hatched during the period of peak Hg concentrations in prey fish. These results illustrate the importance of short-term temporal variation in small fish Hg concentrations for both Hg monitoring programs and assessing wildlife risk.

  6. A Bioassay System Using Bioelectric Signals from Small Fish

    Science.gov (United States)

    Terawaki, Mitsuru; Soh, Zu; Hirano, Akira; Tsuji, Toshio

    Although the quality of tap water is generally examined using chemical assay, this method cannot be used for examination in real time. Against such a background, the technique of fish bioassay has attracted attention as an approach that enables constant monitoring of aquatic contamination. The respiratory rhythms of fish are considered an efficient indicator for the ongoing assessment of water quality, since they are sensitive to chemicals and can be indirectly measured from bioelectric signals generated by breathing. In order to judge aquatic contamination accurately, it is necessary to measure bioelectric signals from fish swimming freely as well as to stably discriminate measured signals, which vary between individuals. However, no bioassay system meeting the above requirements has yet been established. This paper proposes a bioassay system using bioelectric signals generated from small fish in free-swimming conditions. The system records signals using multiple electrodes to cover the extensive measurement range required in a free-swimming environment, and automatically discriminates changes in water quality from signal frequency components. This discrimination is achieved through an ensemble classification method using probability neural networks to solve the problem of differences between individual fish. The paper also reports on the results of related validation experiments, which showed that the proposed system was able to stably discriminate between water conditions before and after bleach exposure.

  7. The Effects of Exurbanization on Bird and Macroinvertebrate Communities in Deciduous Forests on the Cumberland Plateau, Tennessee

    Directory of Open Access Journals (Sweden)

    Jordan M. Casey

    2009-01-01

    Full Text Available To investigate the potential causes of changes to bird communities in exurban areas, we examined the relationship between bird and macroinvertebrate communities in exurbanized forest. We randomly located sampling points across a gradient of exurbanization. We used point counts to quantify bird communities and sweep netting, soil cores, pitfalls, and frass collectors to quantify macroinvertebrates. Bird communities had higher richness and abundance in exurban areas compared to undeveloped forests, and lost some species of conservation concern but gained others. The macroinvertebrate community was slightly more abundant in exurban areas, with a slight shift in taxonomic composition. The abundance of macroinvertebrates in soil cores (but not pitfalls predicted the abundance of ground-foraging birds. The abundance of macroinvertebrates in sweep nets was not associated with the abundance of aerial insectivore birds. Exurbanization therefore appears to change bird and macroinvertebrate communities, but to a lesser extent than agricultural forest fragmentation or intensive urbanization.

  8. Influence of peak flow changes on the macroinvertebrate drift downstream of a Brazilian hydroelectric dam.

    Science.gov (United States)

    Castro, D M P; Hughes, R M; Callisto, M

    2013-11-01

    Successive daily peak flows from hydropower plants can disrupt aquatic ecosystems and alter the composition and structure of macroinvertebrates downstream. We evaluated the influence of peak flow changes on macroinvertebrate drift downstream of a hydroelectric plant as a basis for determining ecological flows that might reduce the disturbance of aquatic biota. The aim of this study was to assess the influence of flow fluctuations on the seasonal and daily drift patterns of macroinvertebrates. We collected macroinvertebrates during fixed flow rates (323 m3.s-1 in the wet season and 111 m3.s-1 in the dry season) and when peak flows fluctuated (378 to 481 m3.s-1 in the wet season, and 109 to 173 m3.s-1 in the dry season) in 2010. We collected 31,924 organisms belonging to 46 taxa in the four sampling periods. Taxonomic composition and densities of drifting invertebrates differed between fixed and fluctuating flows, in both wet and dry seasons, but family richness varied insignificantly. We conclude that macroinvertebrate assemblages downstream of dams are influenced by daily peak flow fluctuations. When making environmental flow decisions for dams, it would be wise to consider drifting macroinvertebrates because they reflect ecological changes in downstream biological assemblages.

  9. Concordance between macrophytes and macroinvertebrates in a Mediterranean river of central Apennine region.

    Science.gov (United States)

    Traversetti, Lorenzo; Scalici, Massimiliano; Ginepri, Valeria; Manfrin, Alessandro; Ceschin, Simona

    2014-05-01

    The main aim of this study was to improve the knowledge about the concordance among macrophytes and macroinvertebrates to provide complementary information and facilitate the procedures for quality assessment of river ecosystems. Macrophytes and macroinvertebrates were collected in 11 sampling sites along a central Apennine calcareous river in October 2008 and June 2009. The concordance between the two biomonitoring groups was tested according to several environmental parameters. The comparison of data matrix similarities by Mantel test showed differences in the assemblage of macrophytes and macroinvertebrates along the river since correlation values were 0.04, p > 0.05 in October 2008 and 0.39, p > 0.05 in June 2009. The study revealed lack of concordance between the two groups, emphasizing that the information provided by macrophytes and macroinvertebrates does not overlap in terms of response to environmental parameters. Indeed, the two different biological groups resulted useful descriptors of different parameters. Together, they could represent a complementary tool to reflect the river environmental quality.

  10. Intensive removal of signal crayfish (Pacifastacus leniusculus) from rivers increases numbers and taxon richness of macroinvertebrate species.

    Science.gov (United States)

    Moorhouse, Tom P; Poole, Alison E; Evans, Laura C; Bradley, David C; Macdonald, David W

    2014-02-01

    Invasive species are a major cause of species extinction in freshwater ecosystems, and crayfish species are particularly pervasive. The invasive American signal crayfish Pacifastacus leniusculus has impacts over a range of trophic levels, but particularly on benthic aquatic macroinvertebrates. Our study examined the effect on the macroinvertebrate community of removal trapping of signal crayfish from UK rivers. Crayfish were intensively trapped and removed from two tributaries of the River Thames to test the hypothesis that lowering signal crayfish densities would result in increases in macroinvertebrate numbers and taxon richness. We removed 6181 crayfish over four sessions, resulting in crayfish densities that decreased toward the center of the removal sections. Conversely in control sections (where crayfish were trapped and returned), crayfish density increased toward the center of the section. Macroinvertebrate numbers and taxon richness were inversely correlated with crayfish densities. Multivariate analysis of the abundance of each taxon yielded similar results and indicated that crayfish removals had positive impacts on macroinvertebrate numbers and taxon richness but did not alter the composition of the wider macroinvertebrate community. Synthesis and applications: Our results demonstrate that non-eradication-oriented crayfish removal programmes may lead to increases in the total number of macroinvertebrates living in the benthos. This represents the first evidence that removing signal crayfish from riparian systems, at intensities feasible during control attempts or commercial crayfishing, may be beneficial for a range of sympatric aquatic macroinvertebrates.

  11. Impact of heavy metals on macro-invertebrate fauna of the thaddo stream

    International Nuclear Information System (INIS)

    Nazneen, S.; Begum, F.; Sharmeen, R.; Ahmed, Z.

    2003-01-01

    Impact of some heavy metals like zinc, lead, copper, chromium and cadmium were studied at four spots on the macro-invertebrate fauna of the Thaddo stream, a tributary of Malir River. This was in correlation with an earlier study on the physico-chemical aspects of water which showed a severe pollution in this stream. Present data for the qualitative and quantitative analyses of macro-invertebrates and the ranges of heavy metals (Zn 0.5-3.5, Pb 0.90-1.42, Cu 0.35-0.93, Cr 0.0-0.08 and Cd 0.003-0.01 ppm) in the water samples also indicate high level of pollution in the stream. Macro-invertebrate fauna comprises only of aquatic insects which include larvae of Chironomus spp., adults of the Notonectus sp., and nymphs of Gomphus sp. (dragon fly) belonging to the order Diptera , Hemiptera and Odonata, respectively. Quantitatively Notonectus sp. predominated and followed by Chironomus larvae. The maximum concentrations of all heavy metals were recorded at spot 3. A general trend of increase was observed from up stream to down stream regions particularly in the level of zinc. However, a reverse trend was observed in the abundance of macro-invertebrates with a great reduction at spot 4. The statistical analysis of the data generally indicates a negative correlation between the values of the studied heavy metals and the abundance of macro-invertebrates throughout this study. (author)

  12. [Effect of environmental factors on macroinvertebrate community structure in the Huntai River basin in the Huntai River basin].

    Science.gov (United States)

    Li, Yan-li; Li, Yan-fen; Xu, Zong-xue

    2015-01-01

    In May-June 2012, macroinvertebrates were investigated at 66 sampling sites in the Huntai River basin in Northeast of China. A total of 72 macrobenthos species were collected, of which, 51 species (70.83%) were aquatic insects, 10 species (13.89%) were mollusks, 7 species (9.72%) were annelids, and 4 species (5.56%) were arthropods. First, 13 candidate metrics (EPT taxa, Dominant taxon%, Ephemeroptera%, Trichoptera%, mollusks%, Heptageniidae/Ephemeroptera; Hydropsychidae/ Trichoptera, Oligochaeta%, intolerant taxon% , tolerant taxon%, Collector%, Clingers%, Shannon-wiener index.) which belonged to six types were chosen to represent macroinvertebrate community structure by correlation analysis. Then, relationships between anthropogenic and physiography pressures and macroinvertebrate community structure variables were measured using redundancy analysis. Then, this study compared the relative influences of anthropogenic and physiographic pressures on macroinvertebrate community structure and the relative influences of anthropogenic pressures at reach, riparian and catchment scales by pRDA. The results showed all environmental factors explained 72.23% of the variation of macroinvertebrate community structure. In addition, a large proportion of the explained variability in macroinvertebrate community structure was related to anthropogenic pressures (48.9%) and to physiographic variables (11.8%), anthropogenic pressures at reach scale influenced most significantly macroinvertebrate community structure which explained 35.3% of the variation of macroinvertebrate community structure. pH, habitat, TN, CODMn, hardness, conductivity, total dissolved particle and ammonia influenced respectively explained 4%, 3.6%, 1.8%, 1.7%, 1.7%, 0.9%, 0.9% and 0.9% of the variation of macroinvertebrate community structure. The land use at riparian and catchment scale respectively explained 10% and 7% of the variation of macroinvertebrate community structure. Finally, the relationships of

  13. Characterization of water quality and biological communities, Fish Creek, Teton County, Wyoming, 2007-2011

    Science.gov (United States)

    Eddy-Miller, Cheryl A.; Peterson, David A.; Wheeler, Jerrod D.; Edmiston, C. Scott; Taylor, Michelle L.; Leemon, Daniel J.

    2013-01-01

    Wyoming. Especially in the winter, the proportionately large, continuous gain of groundwater into Fish Creek in the perennial section keeps most of the creek free of ice. Because sunlight can still reach the streambed in Fish Creek and the water is still flowing, aquatic plants continue to photosynthesize in the winter, albeit at a lower level of productivity. Additionally, the cobble and large gravel substrate in Fish Creek provides excellent attachment points for aquatic plants, and when combined with Fish Creek’s channel stability allows rapid growth of aquatic plants once conditions allow during the spring. The aquatic plant community of Fish Creek was different than most streams in Wyoming in that it contains many different macrophytes—including macroalgae such as long streamers of Cladophora, aquatic vascular plants, and moss; most other streams in the state contain predominantly algae. From the banks of Fish Creek, the bottom of the stream sometimes appeared to be a solid green carpet. A shift was observed from higher amounts of microalgae in April/May to higher amounts macrophytes in August and October, and differences in the relative abundance of microalgae and macrophytes were statistically significant between seasons. Differences in dissolved-nitrate concentrations and in the nitrogen-to-phosphorus ratio were significantly different between seasons, as concentrations of dissolved nitrate decreased from April/May to August and October. It is likely that dissolved-nitrate concentrations in Fish Creek were lower in August and October because macrophytes were quickly utilizing the nutrient, and a negative correlation between macro-phytes and nitrate was found. Macroinvertebrates also were sampled because of their role as indicators of water quality and their documented responses to perturbation such as degradation of water quality and habitat. Statistically significant seasonal differences were noted in the macroinvertebrate community. Taxa richness and

  14. A prototype splitter apparatus for dividing large catches of small fish

    Science.gov (United States)

    Stapanian, Martin A.; Edwards, William H.

    2012-01-01

    Due to financial and time constraints, it is often necessary in fisheries studies to divide large samples of fish and estimate total catch from the subsample. The subsampling procedure may involve potential human biases or may be difficult to perform in rough conditions. We present a prototype gravity-fed splitter apparatus for dividing large samples of small fish (30–100 mm TL). The apparatus features a tapered hopper with a sliding and removable shutter. The apparatus provides a comparatively stable platform for objectively obtaining subsamples, and it can be modified to accommodate different sizes of fish and different sample volumes. The apparatus is easy to build, inexpensive, and convenient to use in the field. To illustrate the performance of the apparatus, we divided three samples (total N = 2,000 fish) composed of four fish species. Our results indicated no significant bias in estimating either the number or proportion of each species from the subsample. Use of this apparatus or a similar apparatus can help to standardize subsampling procedures in large surveys of fish. The apparatus could be used for other applications that require dividing a large amount of material into one or more smaller subsamples.

  15. Risk assessment for fish passage through small, low-head turbines

    Energy Technology Data Exchange (ETDEWEB)

    Turnpenny, A.W.H.; Clough, S.; Hanson, K.P.; Ramsay, R.; McEwan, D.

    2000-07-01

    This report summarises the findings of a study to improve the accuracy of prediction methods for fish fatalities for small-head Francis and Kaplan propeller turbine designs and gives details of computational fluid dynamic modelling to estimate pressure fluxes and shear stresses. Biological data is reviewed, and the STRIKER Excel spreadsheet model is used to predict death caused by pressure flux, shear turbulence, and blade strike. Field validation is discussed, and drawings of the Francis 1 and Kaplan 1 turbines, results of the fish passage trials, and STRIKER instructions and sample runs are presented in the appendices.

  16. Risk assessment for fish passage through small, low-head turbines

    International Nuclear Information System (INIS)

    Turnpenny, A.W.H.; Clough, S.; Hanson, K.P.; Ramsay, R.; McEwan, D.

    2000-01-01

    This report summarises the findings of a study to improve the accuracy of prediction methods for fish fatalities for small-head Francis and Kaplan propeller turbine designs and gives details of computational fluid dynamic modelling to estimate pressure fluxes and shear stresses. Biological data is reviewed, and the STRIKER Excel spreadsheet model is used to predict death caused by pressure flux, shear turbulence, and blade strike. Field validation is discussed, and drawings of the Francis 1 and Kaplan 1 turbines, results of the fish passage trials, and STRIKER instructions and sample runs are presented in the appendices

  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. Metal balance shift induced in small fresh water fish by several environmental stresses

    International Nuclear Information System (INIS)

    Yukawa, Masae; Iso, Hiroyuki; Kodama, Kumiko; Imaseki, Hitoshi; Aoki, Kazuko; Ishikawa, Yuji

    2005-01-01

    Balance of essential elements in organisms might be changed by environmental stresses. Small fresh water fish, Medaka, was burdened with X-ray irradiation (total dose: 17 Gy), keeping in salty water (70% NaCl of sea water) and keeping in metal containing water (10 ppm of Cr and Co). These stresses are not lethal doses. Essential elements in liver, gall bladder, kidney, spleen, heart and brain in the stress-loaded fish were measured by PIXE method and compared with a control fish to determine the effect of the stresses. Various changes of the elemental contents were observed. Effect of X-ray irradiation was the smallest among the stresses. Relatively high content elements such as P, S, Cl and K were hardly affected with the stresses examined in this work. The effect of Cr on the metal balance seems to be larger than the other stresses. As PIXE method can analyze many elements in a small sample simultaneously, change of elemental distribution in small organisms induced by environmental stresses can be determined readily. (author)

  19. Effects of sediment quality on macroinvertebrates in the Sunraysia region of the Murray-Darling Rivers, Australia

    Energy Technology Data Exchange (ETDEWEB)

    Sharley, David J. [Centre for Environmental Stress and Adaptation Research-Hoffmann Laboratory, Zoology Department, University of Melbourne, Level 2, Bio 21 Institute, 30 Flemington Road, Parkville, Victoria 3010 (Australia)], E-mail: sharleyd@unimelb.edu.au; Hoffmann, Ary A. [Centre for Environmental Stress and Adaptation Research-Hoffmann Laboratory, Zoology Department, University of Melbourne, Level 2, Bio 21 Institute, 30 Flemington Road, Parkville, Victoria 3010 (Australia); Pettigrove, Vincent [Research and Technology, Melbourne Water, PO Box 4342, Melbourne, Victoria 3001 (Australia)

    2008-12-15

    A field-based microcosm approach was tested to identify deterioration of sediment quality in waterways using freshwater macroinvertebrates. The method can potentially identify the nature of contaminants based on species-specific responses. Sediments were collected from the Murray and Darling Rivers and irrigation drains within the Sunraysia region of south-eastern Australia and compared to non-polluted reference sediment. Clean sediments were also spiked with fertiliser to test whether nutrients affected the aquatic fauna. Seven of the eight sediments from the Sunraysia region had a negative impact on the macroinvertebrates, in particular sediment from the Darling River, which supported an impoverished fauna. Three species of chironomid showed varied responses to sediment quality and, although it was hypothesised that nutrients may have impacted on the macroinvertebrate fauna, the results suggest that other pollutants are also involved. The field-based microcosm method proved effective for determining the impact of sediment quality on indigenous macroinvertebrates. - Sediment quality effects on freshwater macroinvertebrates are isolated.

  20. Effects of sediment quality on macroinvertebrates in the Sunraysia region of the Murray-Darling Rivers, Australia

    International Nuclear Information System (INIS)

    Sharley, David J.; Hoffmann, Ary A.; Pettigrove, Vincent

    2008-01-01

    A field-based microcosm approach was tested to identify deterioration of sediment quality in waterways using freshwater macroinvertebrates. The method can potentially identify the nature of contaminants based on species-specific responses. Sediments were collected from the Murray and Darling Rivers and irrigation drains within the Sunraysia region of south-eastern Australia and compared to non-polluted reference sediment. Clean sediments were also spiked with fertiliser to test whether nutrients affected the aquatic fauna. Seven of the eight sediments from the Sunraysia region had a negative impact on the macroinvertebrates, in particular sediment from the Darling River, which supported an impoverished fauna. Three species of chironomid showed varied responses to sediment quality and, although it was hypothesised that nutrients may have impacted on the macroinvertebrate fauna, the results suggest that other pollutants are also involved. The field-based microcosm method proved effective for determining the impact of sediment quality on indigenous macroinvertebrates. - Sediment quality effects on freshwater macroinvertebrates are isolated

  1. Do small fish mean no voucher? Using a flatbed desktop scanner to document larval and small specimens before destructive analyses

    Czech Academy of Sciences Publication Activity Database

    Kalous, L.; Šlechtová, Věra; Petrtýl, M.; Kohout, Jan; Čech, Martin

    2010-01-01

    Roč. 26, č. 4 (2010), s. 614-617 ISSN 0175-8659 R&D Projects: GA ČR GA206/06/1371; GA ČR GP206/09/P266 Institutional research plan: CEZ:AV0Z50450515; CEZ:AV0Z60170517 Keywords : small fish * voucher * desktop scanner Subject RIV: GL - Fishing Impact factor: 0.945, year: 2010

  2. Benthic macroinvertebrate assemblages in mangroves and open ...

    African Journals Online (AJOL)

    Benthic macroinvertebrate assemblages in mangroves and open intertidal areas on the Dar es Salaam coast, Tanzania. ... it is recommended that conservation efforts along the Tanzanian coast should focus here. Keywords: benthic macrofauna, community structure, littoral zone, Tanganyika, Western Indian Ocean ...

  3. 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...... 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 gradient of expected pesticide exposure. A paired-reach approach was applied to differentiate...... 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...

  4. Born small, die young: Intrinsic, size-selective mortality in marine larval fish

    KAUST Repository

    Garrido, S.

    2015-11-24

    Mortality during the early stages is a major cause of the natural variations in the size and recruitment strength of marine fish populations. In this study, the relation between the size-at-hatch and early survival was assessed using laboratory experiments and on field-caught larvae of the European sardine (Sardina pilchardus). Larval size-at-hatch was not related to the egg size but was significantly, positively related to the diameter of the otolith-at-hatch. Otolith diameter-at-hatch was also significantly correlated with survival-at-age in fed and unfed larvae in the laboratory. For sardine larvae collected in the Bay of Biscay during the spring of 2008, otolith radius-at-hatch was also significantly related to viability. Larval mortality has frequently been related to adverse environmental conditions and intrinsic factors affecting feeding ability and vulnerability to predators. Our study offers evidence indicating that a significant portion of fish mortality occurs during the endogenous (yolk) and mixed (yolk /prey) feeding period in the absence of predators, revealing that marine fish with high fecundity, such as small pelagics, can spawn a relatively large amount of eggs resulting in small larvae with no chances to survive. Our findings help to better understand the mass mortalities occurring at early stages of marine fish.

  5. Born small, die young: Intrinsic, size-selective mortality in marine larval fish

    KAUST Repository

    Garrido, S.; Ben-Hamadou, R.; Santos, A.M.P.; Ferreira, S.; Teodó sio, M.A.; Cotano, U.; Irigoien, Xabier; Peck, M.A.; Saiz, E.; Ré , P.

    2015-01-01

    Mortality during the early stages is a major cause of the natural variations in the size and recruitment strength of marine fish populations. In this study, the relation between the size-at-hatch and early survival was assessed using laboratory experiments and on field-caught larvae of the European sardine (Sardina pilchardus). Larval size-at-hatch was not related to the egg size but was significantly, positively related to the diameter of the otolith-at-hatch. Otolith diameter-at-hatch was also significantly correlated with survival-at-age in fed and unfed larvae in the laboratory. For sardine larvae collected in the Bay of Biscay during the spring of 2008, otolith radius-at-hatch was also significantly related to viability. Larval mortality has frequently been related to adverse environmental conditions and intrinsic factors affecting feeding ability and vulnerability to predators. Our study offers evidence indicating that a significant portion of fish mortality occurs during the endogenous (yolk) and mixed (yolk /prey) feeding period in the absence of predators, revealing that marine fish with high fecundity, such as small pelagics, can spawn a relatively large amount of eggs resulting in small larvae with no chances to survive. Our findings help to better understand the mass mortalities occurring at early stages of marine fish.

  6. Quantification of environment-driven changes in epiphytic macroinvertebrate communities associated to Phragmites australis

    Directory of Open Access Journals (Sweden)

    Miguel CAÑEDO-ARGÜELLES

    2009-08-01

    Full Text Available The epiphytic macroinvertebrate communities associated with the Common Reed, Phragmites australis (Cav. Trin. ex Steudel, were examined seasonally from summer 2004 to spring 2005 in eleven coastal lagoons of the Llobregat Delta (NE Spain following the method proposed by Kornijów & Kairesalo (1994. The aims of the study were to: 1 characterise and quantify changes in epiphytic macroinvertebrate communities along environmental gradients; 2 assess the contribution of elements of the epiphytic compartment to structuring the community; 3 define the optima and tolerances of selected epiphytic macroinvertebrate taxa for the most relevant ecological factors responsible for assemblage composition; and 4 identify possible epiphytic species assemblages that would allow a lagoon’s typology to be established, as well as their representative indicator species. Communities showed statistically significant seasonal variation, with two faunal peaks: one in summer, with high chironomid densities, and the other in winter, with high naidid densities. These peaks showed a clear response to the influence of environmental factors. Salinity explained the highest percentage of total variance (36%, while trophic variables (nutrients, phytoplanktonic chlorophyll-a, and total organic carbon and epiphyton biomass (19.2 and 4% of total variance explained, respectively were secondary. Three different epiphytic macroinvertebrate species assemblages could be defined. These assemblages were directly linked to conductivity conditions, which determined the rate of survival of certain taxa, and to the existence of a direct connection with the sea, which permitted the establishment of "brackish-water" species. In spite of the existence of these species assemblages, the species composition and biomass of epiphytic macroinvertebrates and epiphyton differed substantially between lagoons; both elements were subject to changes in the environment, which finally determined the site

  7. Summer co-existence of small-sized cyprinid and percid individuals in natural and impounded stretches of a lowland river: food niche partitioning among fishes.

    Science.gov (United States)

    Lik, J; Dukowska, M; Grzybkowska, M; Leszczyńska, J

    2017-04-01

    Due to changes of discharge regime downstream of a dam reservoir, an alluvial natural stretch of the Warta River changed to a macrophyte-dominated ecosystem. Large patches of submersed, aquatic macrophytes appeared in summer and their effect is analysed in this study. These patches contained enriched macroinvertebrate assemblages (epiphyton and benthos) and they were refuge for both zooplankton and young fishes released from the reservoir. Despite these altered conditions in this stretch, roach Rutilus rutilus, perch Perca fluviatilis and ruffe Gymnocephalus cernua dominated, as they did in the natural backwater. Fishes were sampled every 2 weeks from June to August, together with their food resources to assess the partitioning of the diet among small individuals of the three species in both stretches (the natural and affected ones). The aim of the analysis was to answer how animal food associated with water plants was partitioned between the species. In both stretches, G. cernua were primarily benthivorous, but epiphytic fauna, zooplankton and large-sized benthic chironomid larvae replaced lack of many large, benthic insects in the tailwater. Levins' food breath index decreased from 0·36 in the backwater to 0·29 in the tailwater. An opposite trend was observed for P. fluviatilis occurring among macrophytes. Perca fluviatilis were competitors of R. rutilus and took food not only in or on the river bed, but also in the water column. They ate zooplankton and epiphytic fauna and Levins' index increased from 0·32 to 0·44 in the tailwater. Rutilus rutilus fed on adult insects, algae and plant fragments in the natural stretch. In the tailwater, these food types were chiefly complemented by zooplankton. Despite this, the niche breadth of R. rutilus was similar at the two sites. Abundance of food associated with the macrophytes appeared to facilitate cohabitation in the abundant fish populations, but P. fluviatilis appeared to benefit the most in the altered river

  8. Marine sediment sample pre-processing for macroinvertebrates metabarcoding: mechanical enrichment and homogenization

    Directory of Open Access Journals (Sweden)

    Eva Aylagas

    2016-10-01

    Full Text Available Metabarcoding is an accurate and cost-effective technique that allows for simultaneous taxonomic identification of multiple environmental samples. Application of this technique to marine benthic macroinvertebrate biodiversity assessment for biomonitoring purposes requires standardization of laboratory and data analysis procedures. In this context, protocols for creation and sequencing of amplicon libraries and their related bioinformatics analysis have been recently published. However, a standardized protocol describing all previous steps (i.e. processing and manipulation of environmental samples for macroinvertebrate community characterization is lacking. Here, we provide detailed procedures for benthic environmental sample collection, processing, enrichment for macroinvertebrates, homogenization, and subsequent DNA extraction for metabarcoding analysis. Since this is the first protocol of this kind, it should be of use to any researcher in this field, having the potential for improvement.

  9. Effects of near-bed turbulence and micro-topography on macroinvertebrate movements across contrasting gravel-bed surfaces (Invited)

    Science.gov (United States)

    Buffin-Belanger, T. K.; Rice, S. P.; Reid, I.; Lancaster, J.

    2009-12-01

    Fluvial habitats can be described from a series of physical variables but to adequately address the habitat quality it becomes necessary to develop an understanding that combines the physical variables with the behaviour of the inhabitating organisms. The hypothesis of flow refugia provide a rational that can explain the persistence of macroinvertebrate communities in gravel-bed rivers when spates occur. The movement behaviour of macroinvertebrates is a key element to the flow refugia hypothesis, but little is known about how local near-bed turbulence and bed microtopography may affect macroinvertebrate movements. We reproduced natural gravel-bed substrates with contrasting gravel bed textures in a large flume where we were able to document the movement behaviour of the cased caddisfly Potamophylax latipennis for a specific discharge. The crawling paths and drift events of animals were analysed from video recordings. Characteristics of movements differ from one substrate to another. The crawling speed is higher for the small grain-size substrates but the mean travel distance remains approximately the same between substrates. For each substrate, the animals tended to follow consistent paths across the surface. The number of drift events and mean distance drifted is higher for the small grain-size substrate. ADV measurements close to the boundary allow detailed characterisation of near-bed hydraulic variables, including : skewness coefficients, TKE, UV correlation coefficients and integral time scales from autocorrelation analysis. For these variables, the vertical patterns of turbulence parameters are similar between the substrates but the amplitude of the average values and standard errors vary significantly. The spatial distribution of this variability is considered in relation to the crawling paths. It appears that the animals tend to crawl within areas of the substrate where low flow velocities and low turbulent kinetic energies are found, while sites that

  10. Macroinvertebrate community response to acid mine drainage in rivers of the High Andes (Bolivia)

    International Nuclear Information System (INIS)

    Van Damme, Paul Andre; Hamel, Caroli; Ayala, Alfredo; Bervoets, Lieven

    2008-01-01

    Several High Andes Rivers are characterized by inorganic water pollution known as acid mine drainage (AMD). The aim of this study was to assess the relationship between metal concentrations in the sediments and the macroinvertebrate communities in two river basins affected by AMD. In general, the taxon diversity of the macroinvertebrate community at the family level was low. The concentrations of Cd, Cu, Zn, Pb and Ni at mining sites were higher than at unpolluted sites. The pH of the water was alkaline (7.0-8.5) in unpolluted sites, whereas it dropped to very low values (<3) at mining sites. Redundancy Analysis (RDA) showed that pH was the best predictor of macroinvertebrate community richness. The number of macroinvertebrate families decreased gradually with increasing acidity, both in pools and riffles, though it is suggested that riffle communities were more affected because they are in closer contact with the acid water. - Community response to AMD

  11. Trophodynamics and diet overlap of small pelagic fish species in the Bay of Biscay

    KAUST Repository

    Bachiller, E

    2015-08-27

    Small pelagic fish are the link between planktonic production and higher trophic levels. Competition for resources may play a role in the population dynamics of species, some of them probably standing out from the others due to greater feeding success. It is therefore important to understand the trophic niche of species overlapping both spatially and temporally. In this study, we have investigated the diet, prey preference, trophic niche breadth and diet overlap of the 8 major small pelagic species (anchovy, sardine, sprat, Atlantic and Mediterranean horse mackerel, bogue, Atlantic mackerel and Atlantic chub mackerel) inhabiting the Bay of Biscay. Results indicate that all fish feed mainly on calanoid copepods, incorporating larger prey like euphausiids and decapods to complete their diet. Differences in ingested prey diversity seem to be more limited by the available zooplankton at sea than by a specific diet preference by fish species, resulting in an overall high diet overlap, especially within clupeids but also between clupeids and other (larger) predator species. Consumption estimations for different prey groups could therefore determine whether such a large diet overlap between small pelagic fish, together with spatial co-occurrence, results in competition or enhances the effects of intraguild predation, which is important in terms of an ecosystem approach to fisheries management.

  12. Trophodynamics and diet overlap of small pelagic fish species in the Bay of Biscay

    KAUST Repository

    Bachiller, E; Irigoien, Xabier

    2015-01-01

    Small pelagic fish are the link between planktonic production and higher trophic levels. Competition for resources may play a role in the population dynamics of species, some of them probably standing out from the others due to greater feeding success. It is therefore important to understand the trophic niche of species overlapping both spatially and temporally. In this study, we have investigated the diet, prey preference, trophic niche breadth and diet overlap of the 8 major small pelagic species (anchovy, sardine, sprat, Atlantic and Mediterranean horse mackerel, bogue, Atlantic mackerel and Atlantic chub mackerel) inhabiting the Bay of Biscay. Results indicate that all fish feed mainly on calanoid copepods, incorporating larger prey like euphausiids and decapods to complete their diet. Differences in ingested prey diversity seem to be more limited by the available zooplankton at sea than by a specific diet preference by fish species, resulting in an overall high diet overlap, especially within clupeids but also between clupeids and other (larger) predator species. Consumption estimations for different prey groups could therefore determine whether such a large diet overlap between small pelagic fish, together with spatial co-occurrence, results in competition or enhances the effects of intraguild predation, which is important in terms of an ecosystem approach to fisheries management.

  13. Short-term effects of visitor trampling on macroinvertebrates in karst streams in an ecotourism region.

    Science.gov (United States)

    Escarpinati, Suzana Cunha; Siqueira, Tadeu; Medina, Paulino Barroso; de Oliveira Roque, Fabio

    2014-03-01

    In order to evaluate the potential risks of human visitation on macroinvertebrate communities in streams, we investigated the effect of trampling using two short-term experiments conducted in a Brazilian ecotourism karst region. We asked three questions: (a) Does trampling increase the drift rate of aquatic macroinvertebrates and organic matter? (b) Does trampling change the macroinvertebrate community organization? (c) If trampling alters the community structure, is a short time (5 days, a between weekends interval - peaks of tourism activities) sufficient for community restructuring? Analysis of variance of richness, total abundance, abundance of the most abundant genus (e.g., Simothraulopsis and Callibaetis), and community composition showed that trampling immediately affects macroinvertebrate community and that the intervals between the peaks of visitation (5 days) are not sufficient to complete community restructuring. Considering that bathing areas receive thousands of visitors every year and that intervals of time without visitation are nearly nonexistent, we suspect that the negative effects on the macroinvertebrate community occur in a cumulative way. Finally, we discuss some simple procedures that could potentially be used for reducing trampling impacts in lotic environments.

  14. 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.

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

    International Nuclear Information System (INIS)

    Griffin, M.A.; Herring, M.K.

    1990-01-01

    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/m 2 in 1986 to 8948.1--11,694.1 organisms/m 2 in 1988). Annual mean biomass also increased (ranging from 0.749--0.907g AFDM/m 2 in 1986 to 2074--11,322 g AFDM/m 2 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

  16. Few data but many fish: marine small-scale fisheries catches for ...

    African Journals Online (AJOL)

    ... substantially under-reported national data puts authorities under serious risk of over-licensing fishing access and mismanaging marine ecosystems and national food security. Keywords: catch rates, catch reconstructions, food security, Malthusian overfishing, small-scale fisheries, sub-Saharan Africa, subsistence fisheries

  17. Influence of salinity and prey presence on the survival of aquatic macroinvertebrates of a freshwater marsh

    Science.gov (United States)

    Kang, Sung-Ryong; King, Sammy L.

    2012-01-01

    Salinization of coastal freshwater environments is a global issue. Increased salinity from sea level rise, storm surges, or other mechanisms is common in coastal freshwater marshes of Louisiana, USA. The effects of salinity increases on aquatic macroinvertebrates in these systems have received little attention, despite the importance of aquatic macroinvertebrates for nutrient cycling, biodiversity, and as a food source for vertebrate species. We used microcosm experiments to evaluate the effects of salinity, duration of exposure, and prey availability on the relative survival of dominant aquatic macroinvertebrates (i.e., Procambarus clarkii Girard, Cambarellus puer Hobbs, Libellulidae, Dytiscidae cybister) in a freshwater marsh of southwestern Louisiana. We hypothesized that increased salinity, absence of prey, and increased duration of exposure would decrease survival of aquatic macroinvertebrates and that crustaceans would have higher survival than aquatic insect taxon. Our first hypothesis was only partially supported as only salinity increases combined with prolonged exposure duration affected aquatic macroinvertebrate survival. Furthermore, crustaceans had higher survival than aquatic insects. Salinity stress may cause mortality when acting together with other stressful conditions.

  18. Use of a parallel artificial membrane system to evaluate passive absorption and elimination in small fish.

    Science.gov (United States)

    Kwon, Jung-Hwan; Katz, Lynn E; Liljestrand, Howard M

    2006-12-01

    A parallel artificial lipid membrane system was developed to mimic passive mass transfer of hydrophobic organic chemicals in fish. In this physical model system, a membrane filter-supported lipid bilayer separates two aqueous phases that represent the external and internal aqueous environments of fish. To predict bioconcentration kinetics in small fish with this system, literature absorption and elimination rates were analyzed with an allometric diffusion model to quantify the mass transfer resistances in the aqueous and lipid phases of fish. The effect of the aqueous phase mass transfer resistance was controlled by adjusting stirring intensity to mimic bioconcentration rates in small fish. Twenty-three simple aromatic hydrocarbons were chosen as model compounds for purposes of evaluation. For most of the selected chemicals, literature absorption/elimination rates fall into the range predicted from measured membrane permeabilities and elimination rates of the selected chemicals determined by the diffusion model system.

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

    International Nuclear Information System (INIS)

    MacCausland, A.; McTammany, M.E.

    2007-01-01

    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

  20. Benthic macroinvertebrates along the soil/water interface of the HUMEX lake 1989-1991

    Energy Technology Data Exchange (ETDEWEB)

    Hargeby, A.; Petersen, R.C. Jr.; Kullberg, A.; Svensson, M. (Univ. of Lund (Sweden))

    1992-01-01

    The taxonomic composition, abundance, and size distribution of benthic macroinvertebrates were studied at the soil/water interface two years before and the first year after the start of artificial acidification of a small catchment and its humic lake. The macroinvertebrate assemblage consisted mainly of predators; dragonflies (Odonata), damselflies (Zygoptera), net-building caddisflies (Polycentropodidae), diving beetles (Dytiscidae), and water bugs (Hemiptera). It is suggested that benthic and planktonic microcrustaceans are important prey for damselflies and that intraguild predation is important for the structure of the community. The typical bog tarn assemblage did not include snails, mussels, or macrocrustaceans, which are algae and detritus feeders known to be affected by low pH. The only potential herbivores on filaments algae and shredders of coarse detritus were case building caddisflies and the ephemeropteran Leptophlebia vespertina, which were all found in low numbers. If the artificial acidification will eliminate these macroinvertebrates, it will have little impact on attached filaments algae, and on processing of coarse detritus. Although there was a general similarity in taxonomic structure on the two sides, significantly higher numbers of dytiscids (Acilius sulcatus and Ilybius spp.) were consistently found on the experimental side than on the control side through the three years of study. The first year after acidification, the number of Zygoptera was lower on the experimental side than on the control side. The abundance on the control side in this year was, however, also higher than in the previous two years. The size distribution of Coenagrion hastulatum, the dominating zygopteran, showed no difference between lake sides. Significant difference between years indicate, however, that size distribution could be used to detect altered growth conditions. 20 refs., 5 figs., 4 tabs.

  1. Promoting a functional macroinvertebrate approach in the biomonitoring of Italian lotic systems

    Directory of Open Access Journals (Sweden)

    Richard W. Merritt

    2016-06-01

    Full Text Available Over fifty years of research on freshwater macroinvertebrates has been driven largely by the state of the taxonomy of these organisms. Significant advances have been and continue to be made in developing ever more refined keys to macroinvertebrate groups. When advances in macroinvertebrate ecological research are restricted by the level of detail in identifications, then analysis by function is a viable alternative. The focus on function, namely adaptations of macroinvertebrates to habitats and the utilization of food resources, has facilitated ecological evaluation of freshwater ecosystems. This classification is based not on what insects eat, but how they obtain their food. These categories are called 'functional feeding groups', as the name implies, denoting their functional role when describing how and where they feed. This is the basis for the functional feeding group (FFG method that was initially developed in the early 1960s. Taxonomy is applied only to the level of detail that allows assignment to one of five functional feeding group categories: detrital shredders, scrapers, filtering collectors, gatherers, and predators. The aim of this short communication, originating from the presentation of R.W. Merritt at the Biomonitoring Symposium in Rome, 2015, is to promote the use of a functional approach in biomonitoring, especially in Italian and European lotic systems. Here, we present two case studies and we discuss the advantages of the method, especially considering the great availability of quantitative data on macroinvertebrates after the implementation of the WFD 2000/60. We are confident that the increase of functional assessment of ecosystem attributes could have important and direct repercussions in the understanding and management of running waters.

  2. Stream Macroinvertebrate Occurrence along Gradients in Organic Pollution and Eutrophication

    DEFF Research Database (Denmark)

    Friberg, Nikolai; Skriver, Jens; Larsen, Søren Erik

    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 Da......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...

  3. Effects of brine contamination from energy development on wetland macroinvertebrate community structure in the Prairie Pothole Region

    Science.gov (United States)

    Preston, Todd M.; Borgreen, Michael J.; Ray, Andrew M.

    2018-01-01

    Wetlands in the Prairie Pothole Region (PPR) of North America support macroinvertebrate communities that are integral to local food webs and important to breeding waterfowl. Macroinvertebrates in PPR wetlands are primarily generalists and well adapted to within and among year changes in water permanence and salinity. The Williston Basin, a major source of U.S. energy production, underlies the southwest portion of the PPR. Development of oil and gas results in the coproduction of large volumes of highly saline, sodium chloride dominated water (brine) and the introduction of brine can alter wetland salinity. To assess potential effects of brine contamination on macroinvertebrate communities, 155 PPR wetlands spanning a range of hydroperiods and salinities were sampled between 2014 and 2016. Brine contamination was documented in 34 wetlands with contaminated wetlands having significantly higher chloride concentrations, specific conductance and percent dominant taxa, and significantly lower taxonomic richness, Shannon diversity, and Pielou evenness scores compared to uncontaminated wetlands. Non-metric multidimensional scaling found significant correlations between several water quality parameters and macroinvertebrate communities. Chloride concentration and specific conductance, which can be elevated in naturally saline wetlands, but are also associated with brine contamination, had the strongest correlations. Five wetland groups were identified from cluster analysis with many of the highly contaminated wetlands located in a single cluster. Low or moderately contaminated wetlands were distributed among the remaining clusters and had macroinvertebrate communities similar to uncontaminated wetlands. While aggregate changes in macroinvertebrate community structure were observed with brine contamination, systematic changes were not evident, likely due to the strong and potentially confounding influence of hydroperiod and natural salinity. Therefore, despite the observed

  4. Microplastic effect thresholds for freshwater benthic macroinvertebrates

    NARCIS (Netherlands)

    Redondo Hasselerharm, P.E.; Dede Falahudin, Dede; Peeters, E.T.H.M.; Koelmans, A.A.

    2018-01-01

    Now that microplastics have been detected in lakes, rivers and estuaries all over the globe, evaluating their effects on biota has become an urgent research priority. This is the first study that aims at determining the effect thresholds for a battery of six freshwater benthic macroinvertebrates

  5. 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...

  6. 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...

  7. Farm-level risk factors for fish-borne zoonotic trematode infection in integrated small-scale fish farms in northern Vietnam.

    Directory of Open Access Journals (Sweden)

    Van Thi Phan

    Full Text Available BACKGROUND: Northern Vietnam is an endemic region for fish-borne zoonotic trematodes (FZT, including liver and intestinal flukes. Humans acquire the FZT infection by eating raw or inadequately cooked fish. The production of FZT-free fish in aquaculture is a key component in establishing a sustainable program to prevent and control the FZT transmission to humans. Interventions in aquaculture should be based on knowledge of the main risk factors associated with FZT transmission. METHODOLOGY/PRINCIPAL FINDINGS: A longitudinal study was carried out from June 2006 to May 2007 in Nam Dinh province, Red River Delta to investigate the development and risk factors of FZT infections in freshwater cultured fish. A total of 3820 fish were sampled six times at two-month intervals from 96 fish farms. Logistic analysis with repeated measurements was used to evaluate potential risk factors based on information collected through questionnaire interviews with 61 fish farm owners. The results showed that the FZT infections significantly increased from first sampling in June to July 2006 (65% to sixth sampling in April to May, 2007 (76%. The liver fluke, Clonorchis sinensis and different zoonotic intestinal flukes including Haplochis pumilio, H. taichui, H. yokogawai, Centrocestus formosanus and Procerovum varium were found in sampled fish. Duration of fish cultured (sampling times, mebendazole drug self-medication of household members, presence of snails in the pond, and feeding fish with green vegetation collected outside fish farms all had a significant effect on the development of FZT prevalence in the fish. CONCLUSIONS/SIGNIFICANCE: The FZT prevalence in fish increased by 11 percentage points during a one-year culture period and the risk factors for the development of infection were identified. Results also highlight that the young fish are already highly infected when stocked into the grow-out systems. This knowledge should be incorporated into control

  8. Catchment land-use effects on littoral macroinvertebrates in response to local habitat structure and trophic state

    DEFF Research Database (Denmark)

    McGoff, Elaine; Sandin, Leif Leonard

    2012-01-01

    macroinvertebrate community structure: trophic status, substrate variables or riparian variables. We also investigated what influence each of these groups of variables has on the other. The impact of large scale land use patterns was also investigated, to determine if macroinvertebrates responded differently in two...... different catchment land use types: impaired and unimpaired. Partial canonical ordination analysis showed that substrate variables were the most important for describing macroinvertebrate community variation in both catchment land use classes, followed by riparian descriptors, with the trophic signal only...

  9. Trophic structure of macroinvertebrates in tropical pasture streams

    Directory of Open Access Journals (Sweden)

    Bruna Neves da Silveira-Manzotti

    Full Text Available Abstract: Aim The aim of this study was to describe the diet of stream macroinvertebrates and to determine their trophic groups. Methods Invertebrates were sampled with D nets in three pasture streams. They were identified to genus level and submitted to gut content analysis, except for fluid feeders such as hemipterans, to which diet data was obtained from the literature. Trophic groups were determined based on a similarity analysis using the Bray-Curtis similarity coefficient. Results Five trophic groups were defined: fine-detritivores (feed mostly on fine particulate organic matter - FPOM, coarse-detritivores/herbivores (feed mostly on coarse particulate organic matter - CPOM - and plant material, omnivores, specialist-predators (prey upon aquatic insects only, and generalist-predators. Ephemeroptera, Diptera (except Tanypodinae, Coleoptera, and Trichoptera (except Smicridea were detritivores. The caddis Macronema (Trichoptera fed exclusively on plant detritus and Tanypodinae and Smicridea were classified as omnivores. The odonate families Calopterygidae and Gomphidae were classified as specialist-predators, while Macrobrachium (Decapoda, Belostoma, and Limnocoris (Hemiptera were generalist-predators. Conclusions The great quantity and frequency of occurrence of FPOM consumed by most taxa highlight the importance of this food resource for macroinvertebrate communities from tropical streams. Furthermore, observed variations on trophic group assignment for some taxa indicate the generalist and opportunistic nature of these aquatic invertebrates. Such findings reinforce the importance of conducting gut content analysis on macroinvertebrates to understand their role in the structure and functioning of tropical streams.

  10. Ecological characterization of two species of exotic fish, pumpkinseed sunfish (Lepomis gibbosus and largemouth bass (Micropterus salmoides in the international Minho river

    Directory of Open Access Journals (Sweden)

    Ana Cristina Lages

    2015-11-01

    Full Text Available The introduction of exotic species is considered the main cause for the decline of native species. The largemouth bass (Micropterus salmoides and pumpkinseed sunfish (Lepomis gibbosus are two native species from North America, introduced in Portugal to enhance sport fishing. However, their diet and great adaptability made them considered predatory and harmful. In order to understand the ecological impact of M. salmoides and L. gibbosus in the international section of the Minho River, three sampling sites were selected: two in Vila Nova de Cerveira and one in Lapela, at distance of the mouth of the river of 17 and 45 Km, respectively. The fish were gathered using fyke nets and trammel nets, electric fishing and fishing rod, with performed samplings since July 2014 until October 2015. For all fish caught the biometric data (weight, total and fork length, gonad and liver weight, sex, stomach contents analysis were registered as well as collection of otoliths and scales for age reading. Both species feed on small macroinvertebrates specially the juveniles while adults of largemouth bass and pumpkinseed sunfish prefer eat fish and gastropods, respectively. Because L. gibbosus is a recent introduction in the Minho river estuary its abundance increased a lot in the last two years and it was possible verify the increase of the fish population average length. With this work it is intended to evaluate the impact in the Minho River estuary of both exotic species studying the population structure, trophic webs and reproduction.

  11. High temperature salting of mince of small sized fish

    OpenAIRE

    Sorinmade, S.O.; Talabi, S.O.; Aliu, A.

    1982-01-01

    Freshly caught small sized fish species were transported to the laboratory gutted and washed before mechanical separation into bone and mince. Duplicate batches of the mince were then treated with seven different concentrations (wt/wt) of sodium chloride before cooking. The cooked mince was divided into two groups, pressed and unpressed. Percentage residual salt in the salted cooked mince, free and press water and salted cooked pressed mince were determined. Also, the moisture contents of...

  12. Scale-dependency of macroinvertebrate communities: responses to contaminated sediments within run-of-river dams.

    Science.gov (United States)

    Colas, Fanny; Archaimbault, Virginie; Devin, Simon

    2011-03-01

    Due to their nutrient recycling function and their importance in food-webs, macroinvertebrates are essential for the functioning of aquatic ecosystems. These organisms also constitute an important component of biodiversity. Sediment evaluation and monitoring is an essential aspect of ecosystem monitoring since sediments represent an important component of aquatic habitats and are also a potential source of contamination. In this study, we focused on macroinvertebrate communities within run-of-river dams, that are prime areas for sediment and pollutant accumulation. Little is known about littoral macroinvertebrate communities within run-of-river dam or their response to sediment levels and pollution. We therefore aimed to evaluate the following aspects: the functional and structural composition of macroinvertebrate communities in run-of-river dams; the impact of pollutant accumulation on such communities, and the most efficient scales and tools needed for the biomonitoring of contaminated sediments in such environments. Two run-of-river dams located in the French alpine area were selected and three spatial scales were examined: transversal (banks and channel), transversal x longitudinal (banks/channel x tail/middle/dam) and patch scale (erosion, sedimentation and vegetation habitats). At the patch scale, we noted that the heterogeneity of littoral habitats provided many available niches that allow for the development of diversified macroinvertebrate communities. This implies highly variable responses to contamination. Once combined on a global 'banks' spatial scale, littoral habitats can highlight the effects of toxic disturbances. Copyright © 2011 Elsevier B.V. All rights reserved.

  13. NOAA/NOS National Centers for Coastal Ocean Science (NCCOS) /Center for Coastal Ocean Science (CCMA) benthic habitat and fish community assessment, La Parguera and Guanica, Puerto Rico, 2011-2012 (NODC Accession 0104343)

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — These data were collected in order to 1) To spatially characterize and monitor the distribution, abundance, and size of both reef fishes and macro-invertebrates...

  14. Relationships among catch, angler catisfaction, and fish assemblage characteristics of an urban small impoundment fishery

    Science.gov (United States)

    Ivasauskas, Tomas J.; Xiong, Wilson N.; Engman, Augustin C.; Fischer, Jesse R.; Kwak, Thomas J.; Rundle, Kirk R.

    2017-01-01

    Urban fisheries provide unique angling opportunities for people from traditionally underrepresented demographics. Lake Raleigh is a 38-ha impoundment located on the North Carolina State University campus in Raleigh. Like many urban fisheries, little is known about angler use and satisfaction or how angling catch rate is related to fish availability in Lake Raleigh. We characterized the recreational fishery and fish assemblage with concurrent creel and boat electrofishing surveys over the course of one year. In total, 245 anglers were interviewed on 68 survey days. On average, anglers spent 1.7 h fishing per trip and caught 0.385 fish h –1. A large proportion of anglers (43.9%) targeted multiple species, whereas 36.5% targeted largemouth bass (Micropterus salmoides), 10.0% targeted panfish (i.e., sunfishes [Lepomis spp.] and crappies [Pomoxis spp.]), and 9.6% targeted catfish (Ameiurus spp. and Ictalurus spp.). Most anglers (69.4%) were satisfied with their experience, and overall satisfaction was unrelated to catch rate. Pulsed-DC boat electrofishing was conducted on 25 dates, and 617 fish were sampled. Angler catch rate was unrelated to electrofishing catch rate, implying that anglers' catch rate was independent of fish density or availability. Our results demonstrate that even minimally managed urban fisheries can provide high angler satisfaction, with limited dedication of management resources. Relationships Among Catch, Angler Satisfaction, and Fish Assemblage Characteristics of an Urban Small Impoundment Fishery (PDF Download Available). Available from: https://www.researchgate.net/publication/316636550_Relationships_Among_Catch_Angler_Satisfaction_and_Fish_Assemblage_Characteristics_of_an_Urban_Small_Impoundment_Fishery [accessed Aug 11, 2017].

  15. Habitat-specific bioaccumulation of methylmercury in invertebrates of small mid-latitude lakes in North America

    Energy Technology Data Exchange (ETDEWEB)

    Chetelat, John, E-mail: john.chetelat@ec.gc.c [Groupe de recherche interuniversitaire en limnologie, Departement de sciences biologiques, Universite de Montreal, Montreal, Quebec H3C 3J7 (Canada); Amyot, Marc; Garcia, Edenise [Groupe de recherche interuniversitaire en limnologie, Departement de sciences biologiques, Universite de Montreal, Montreal, Quebec H3C 3J7 (Canada)

    2011-01-15

    We examined habitat-specific bioaccumulation of methylmercury (MeHg) in aquatic food webs by comparing concentrations in pelagic zooplankton to those in littoral macroinvertebrates from 52 mid-latitude lakes in North America. Invertebrate MeHg concentrations were primarily correlated with water pH, and after controlling for this influence, pelagic zooplankton had significantly higher MeHg concentrations than littoral primary consumers but lower MeHg than littoral secondary consumers. Littoral primary consumers and pelagic zooplankton are two dominant prey for fish, and greater MeHg in zooplankton is likely sufficient to increase bioaccumulation in pelagic feeders. Intensive sampling of 8 lakes indicated that habitat-specific bioaccumulation in invertebrates (of similar trophic level) may result from spatial variation in aqueous MeHg concentration or from more efficient uptake of aqueous MeHg into the pelagic food web. Our findings demonstrate that littoral-pelagic differences in MeHg bioaccumulation are widespread in small mid-latitude lakes. - Methylmercury levels in dominant invertebrate prey for fish differ between littoral and pelagic habitats within a lake.

  16. Habitat-specific bioaccumulation of methylmercury in invertebrates of small mid-latitude lakes in North America

    International Nuclear Information System (INIS)

    Chetelat, John; Amyot, Marc; Garcia, Edenise

    2011-01-01

    We examined habitat-specific bioaccumulation of methylmercury (MeHg) in aquatic food webs by comparing concentrations in pelagic zooplankton to those in littoral macroinvertebrates from 52 mid-latitude lakes in North America. Invertebrate MeHg concentrations were primarily correlated with water pH, and after controlling for this influence, pelagic zooplankton had significantly higher MeHg concentrations than littoral primary consumers but lower MeHg than littoral secondary consumers. Littoral primary consumers and pelagic zooplankton are two dominant prey for fish, and greater MeHg in zooplankton is likely sufficient to increase bioaccumulation in pelagic feeders. Intensive sampling of 8 lakes indicated that habitat-specific bioaccumulation in invertebrates (of similar trophic level) may result from spatial variation in aqueous MeHg concentration or from more efficient uptake of aqueous MeHg into the pelagic food web. Our findings demonstrate that littoral-pelagic differences in MeHg bioaccumulation are widespread in small mid-latitude lakes. - Methylmercury levels in dominant invertebrate prey for fish differ between littoral and pelagic habitats within a lake.

  17. Macroinvertebrate fauna associated with Pistia stratiotes and Nymphoides indica in subtropical lakes (south Brazil

    Directory of Open Access Journals (Sweden)

    EF. Albertoni

    Full Text Available This study was carried out at the Biguás and Polegar lakes, both small environments but at different successional stages. The main objective was to characterize the macroinvertebrate community associated to the aquatic macrophyte stand in each lake in order for this community, the environmental conditions and their water quality to interact. The samples were taken in 2003. The abiotic variables of N and P totals, the temperature, electrical conductivity, pH and dissolved oxygen, as well as the determined clorophyll a concentration were measured. Macroinvertebrates were sampled with a 500 µ mesh size net, separated under a stereomicroscope and identified at the lowest possible taxonomic level, and their densities were shown as the number of individuals per 100 g of macrophyte dry weight. The Shannon-Wiener Diversity Index (H', Pielou evenness (J, frequency of occurrence, abundance and taxa richness were calculated for each invertebrate community. The Lago dos Biguás is undergoing a process of eutrophication and during the study presented a large Pistia stratiotes stand. The Lago Polegar is oligotrophic and had only a small Nymphoides indica bankwe. The macrophyte associated invertebrate communities in each lake were considered significantly different (p < 0.05. Sixty seven taxa were found for the Lago dos Biguás and 32 for the Lago Polegar. For both lakes, most of the taxa were considered rare, with a low dominance in a few months. The taxa with highest densities at Lago dos Biguás were Chironomidae, Daphniidae and Cyclopidae, and Oligochaeta, Chironomidae and Coenagrionidae for Lago Polegar.

  18. Effects of an oil spill on leafpack-inhabiting macroinvertebrates in the Chariton river, Missouri

    Science.gov (United States)

    Poulton, B.C.; Callahan, E.V.; Hurtubise, R.D.; Mueller, B.G.

    1998-01-01

    Artificial leaf packs were used to determine the effects of an oil spill on stream macroinvertebrate communities in the Chariton River, Missouri. Plastic mesh leaf retainers with approximately 10 g of leaves from five tree species were deployed at five sites (two upstream of the spill and three downstream) immediately after the spill and one year later. Four macroinvertebrate species dominating the community at upstream sites were virtually eliminated below the spill, including the stonefly Isoperla bilineata, the caddisfly Potamyia flava, the midge Thienemanniella xena, and blackfly larvae (Simulium sp.). Density of collector and shredder functional groups, and number of shredder taxa differed between upstream sites and the two furthest downstream sites during the 1990 sample period (Kruskal-Wallis w/Bonferroni paired comparisons, experiment wise error rate = 0.05). With one exception, no differences between sites were detected in the 1991-1992 sample period, indicating that the benthic community had at least partially recovered from the oil spill after one year. The odds of obtaining a sample with a small abundance of shredders (abundance < median) in 1990 was significantly greater downstream of the spill than upstream, and the odds of obtaining a sample with a small abundance of shredders at downstream sites was greater in 1990 than in 1991-1992. A similar pattern was observed in abundance and taxa richness of the collector functional group. No significant differences between the two sampling periods were detected at upstream sites. Observed effects appeared to be associated with oil sorption and substrate coating, creating conditions unsuitable for successful colonization.

  19. Quantification of environment-driven changes in epiphytic macroinvertebrate communities associated to Phragmites australis

    OpenAIRE

    Miguel CAÑEDO-ARGÜELLES; Maria RIERADEVALL

    2009-01-01

    The epiphytic macroinvertebrate communities associated with the Common Reed, Phragmites australis (Cav.) Trin. ex Steudel, were examined seasonally from summer 2004 to spring 2005 in eleven coastal lagoons of the Llobregat Delta (NE Spain) following the method proposed by Kornijów & Kairesalo (1994). The aims of the study were to: 1) characterise and quantify changes in epiphytic macroinvertebrate communities along environmental gradients; 2) assess the contribution of elements of the epi...

  20. Impact of pesticides on hyphomycetes leaf processing and macroinvertebrate shredding activity

    DEFF Research Database (Denmark)

    Juul Monberg, Rikke; Rasmussen, Jes; Baatrup-Pedersen, Annette

    , consequently impacting stream dwelling organism feeding on the organic material. The impact of pyrethroid insecticides on stream macroinvertebrates are well studied and increased mortality and drift rate along with decreased feeding activity are well known responses to even very low concentrations (10-100 ng...... organisms have the power to reduce organic matter breakdown and food quality for macroinvertebrates, thereby decreasing ecosystem decomposition rates. We exposed preconditioned leafs of beech (Fagus sylvatica) to the fungicide propiconazole (100, 1000 or 2000 μg/L) and/or the insecticide alpha...

  1. 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.

  2. Metal contamination in benthic macroinvertebrates in a sub-basin in the southeast of Brazil

    Directory of Open Access Journals (Sweden)

    WAC Chiba

    Full Text Available Benthic macroinvertebrates have many useful properties that make possible the use of these organisms as sentinel in biomonitoring programmes in freshwater. Combined with the characteristics of the water and sediment, benthic macroinvertebrates are potential indicators of environmental quality. Thus, the spatial occurrence of potentially toxic metals (Al, Zn, Cr, Co, Cu, Fe, Mn and Ni in the water, sediment and benthic macroinvertebrates samples were investigated in a sub-basin in the southeast of Brazil in the city of São Carlos, São Paulo state, with the aim of verifying the metals and environment interaction with benthic communities regarding bioaccumulation. Hypothetically, there can be contamination by metals in the aquatic environment in the city due to lack of industrial effluent treatment. All samples were analysed by the USEPA adapted method and processed in an atomic absorption spectrophotometer. The sub-basin studied is contaminated by toxic metals in superficial water, sediment and benthic macroinvertebrates. The Bioaccumulation Factor showed a tendency for metal bioaccumulation by the benthic organisms for almost all the metal species. The results show a potential human and ecosystem health risk, contributing to metal contamination studies in aquatic environments in urban areas.

  3. Bioassessment of Choghakhor Wetland using Benthic Macroinvertebrates

    Directory of Open Access Journals (Sweden)

    P. Fathi

    2016-05-01

    Full Text Available In present study, besides investigating benthic communities and their demographics in Choghakhor wetland, the water quality has been evaluated and classified. Then, 10 stations were selected and sampling of benthos was done every 45 days since April 2010 to March 2011, with 3 replications at each station. Samples were obtained by Ekman grab Sampler (surface 400 cm2. The collected samples were separated and fixed by formalin (4%. The Macroinvertebrates samples were identified and counted in laboratory. Generally 25 families of benthic macroinvertebrates belonging to 5 classes and 12 orders were identified. The results were calculated as community measures, including total richness, Shannon - Wiener diversity index and Hilsenhoff Biological index at family level. The results obtained from temporal and spatial changes of data (Statgeraphics software and water qualitative classification using Shannon diversity index conformed to biological Hilsenhoff index. And finally, water quality of wetland was assessed to be polluted in average to high level. According to this study findings, it seems that, these indicators could be used as useful tools for evaluating water supplies quality.

  4. Reach-scale stream restoration in agricultural streams of southern Minnesota alters structural and functional responses of macroinvertebrates

    Science.gov (United States)

    Dolph, Christine L.; Eggert, Susan L.; Magner, Joe; Ferrington, Leonard C.; Vondracek, Bruce C.

    2015-01-01

    Recent studies suggest that stream restoration at the reach scale may not increase stream biodiversity, raising concerns about the utility of this conservation practice. We examined whether reach-scale restoration in disturbed agricultural streams was associated with changes in macroinvertebrate community structure (total macroinvertebrate taxon richness, total macroinvertebrate density, Ephemeroptera, Plecoptera, Trichoptera [EPT] taxon richness, % abundance of EPT taxa) or secondary production (macroinvertebrate biomass over time). We collected macroinvertebrate samples over the course of 1 y from restored and unrestored reaches of 3 streams in southern Minnesota and used generalized least-square (GLS) models to assess whether measures of community structure were related to reach type, stream site, or sampling month. After accounting for effects of stream site and time, we found no significant difference in total taxon richness or % abundance of EPT taxa between restored and unrestored reaches. However, the number of EPT taxa and macroinvertebrate density were significantly higher in restored than in unrestored reaches. We compared secondary production estimates among study reaches based on 95th-percentile confidence intervals generated via bootstrapping. In each study stream, secondary production was significantly (2–3×) higher in the restored than in the unrestored reach. Higher productivity in the restored reaches was largely a result of the disproportionate success of a few dominant, tolerant taxa. Our findings suggest that reach-scale restoration may have ecological effects that are not detected by measures of total taxon richness alone.

  5. 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.

  6. DEVELOPMENT OF A STREAM BENTHIC MACROINVERTEBRATE INTEGRITY INDEX (SBMII) FOR WADEABLE STREAMS IN THE MID-ATLANTIC HIGHLANDS REGION

    Science.gov (United States)

    The Stream Benthic Macroinvertebrate Integrity Index (SBMII), a multimetric biotic index for assessing biological conditions of wadeable streams, was developed using seven macroinvertebrate metrics (Ephemeroptera richness, Plecoptera richness, Trichoptera richness, Collector-Filt...

  7. Functional changes in littoral macroinvertebrate communities in response to watershed-level anthropogenic stress.

    Directory of Open Access Journals (Sweden)

    Katya E Kovalenko

    Full Text Available Watershed-scale anthropogenic stressors have profound effects on aquatic communities. Although several functional traits of stream macroinvertebrates change predictably in response to land development and urbanization, little is known about macroinvertebrate functional responses in lakes. We assessed functional community structure, functional diversity (Rao's quadratic entropy and voltinism in macroinvertebrate communities sampled across the full gradient of anthropogenic stress in Laurentian Great Lakes coastal wetlands. Functional diversity and voltinism significantly decreased with increasing development, whereas agriculture had smaller or non-significant effects. Functional community structure was affected by watershed-scale development, as demonstrated by an ordination analysis followed by regression. Because functional community structure affects energy flow and ecosystem function, and functional diversity is known to have important implications for ecosystem resilience to further environmental change, these results highlight the necessity of finding ways to remediate or at least ameliorate these effects.

  8. Application of a multistate model to estimate culvert effects on movement of small fishes

    Science.gov (United States)

    Norman, J.R.; Hagler, M.M.; Freeman, Mary C.; Freeman, B.J.

    2009-01-01

    While it is widely acknowledged that culverted road-stream crossings may impede fish passage, effects of culverts on movement of nongame and small-bodied fishes have not been extensively studied and studies generally have not accounted for spatial variation in capture probabilities. We estimated probabilities for upstream and downstream movement of small (30-120 mm standard length) benthic and water column fishes across stream reaches with and without culverts at four road-stream crossings over a 4-6-week period. Movement and reach-specific capture probabilities were estimated using multistate capture-recapture models. Although none of the culverts were complete barriers to passage, only a bottomless-box culvert appeared to permit unrestricted upstream and downstream movements by benthic fishes based on model estimates of movement probabilities. At two box culverts that were perched above the water surface at base flow, observed movements were limited to water column fishes and to intervals when runoff from storm events raised water levels above the perched level. Only a single fish was observed to move through a partially embedded pipe culvert. Estimates for probabilities of movement over distances equal to at least the length of one culvert were low (e.g., generally ???0.03, estimated for 1-2-week intervals) and had wide 95% confidence intervals as a consequence of few observed movements to nonadjacent reaches. Estimates of capture probabilities varied among reaches by a factor of 2 to over 10, illustrating the importance of accounting for spatially variable capture rates when estimating movement probabilities with capture-recapture data. Longer-term studies are needed to evaluate temporal variability in stream fish passage at culverts (e.g., in relation to streamflow variability) and to thereby better quantify the degree of population fragmentation caused by road-stream crossings with culverts. ?? American Fisheries Society 2009.

  9. The effect of plant density on epiphytic macroinvertebrates ...

    African Journals Online (AJOL)

    The effect of variations in the density of a submerged macrophyte,Lagarosiphon ilicifolius, on epiphytic macroinvertebrate community structure in the shallow waters of a sheltered bay of Lake Kariba were investigated. The body size class distributions of a mayfly, Cloeon (Ephemeroptera: Baetidae), and the damselfly family, ...

  10. Physico-chemical conditions and macroinvertebrate fauna in the ...

    African Journals Online (AJOL)

    This paper examines the distribution of benthic macroinvertebrates in relation to physico-chemical conditions along 1 035km of the River Nile from Aswan High Dam to Al Kanater Barrage, Cairo. Total Dissolved Salts and several individual chemical variables showed positive linear regression with distance from Aswan.

  11. Macroinvertebrate communities evaluated prior to and following a channel restoration project in Silver Creek, Blaine County, Idaho, 2001-16

    Science.gov (United States)

    MacCoy, Dorene E.; Short, Terry M.

    2017-11-22

    The U.S. Geological Survey, in cooperation with Blaine County and The Nature Conservancy, evaluated the status of macroinvertebrate communities prior to and following a channel restoration project in Silver Creek, Blaine County, Idaho. The objective of the evaluation was to determine whether 2014 remediation efforts to restore natural channel conditions in an impounded area of Silver Creek caused declines in local macroinvertebrate communities. Starting in 2001 and ending in 2016, macroinvertebrates were sampled every 3 years at two long-term trend sites and sampled seasonally (spring, summer, and autumn) in 2013, 2015, and 2016 at seven synoptic sites. Trend-site communities were collected from natural stream-bottom substrates to represent locally established macroinvertebrate assemblages. Synoptic site communities were sampled using artificial (multi-plate) substrates to represent recently colonized (4–6 weeks) assemblages. Statistical summaries of spatial and temporal patterns in macroinvertebrate taxonomic composition at both trend and synoptic sites were completed.The potential effect of the restoration project on resident macroinvertebrate populations was determined by comparing the following community assemblage metrics:Total taxonomic richness (taxa richness);Total macroinvertebrate abundance (total abundance);Ephemeroptera, Plecoptera, Trichoptera (EPT) richness;EPT abundance;Simpson’s diversity; andSimpson’s evenness for periods prior to and following restoration.A significant decrease in one or more metric values in the period following stream channel restoration was the basis for determining impairment to the macroinvertebrate communities in Silver Creek.Comparison of pre-restoration (2001–13) and post‑restoration (2016) macroinvertebrate community composition at trend sites determined that no significant decreases occurred in any metric parameter for communities sampled in 2016. Taxa and EPT richness of colonized assemblages at synoptic sites

  12. 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

  13. Spatial and temporal effects of olive mill wastewaters to stream macroinvertebrates and aquatic ecosystems status.

    Science.gov (United States)

    Karaouzas, Ioannis; Skoulikidis, Nikolaos T; Giannakou, Urania; Albanis, Triantafyllos A

    2011-12-01

    Olive mill wastewater (OMW) is one of the major and most challenging organic pollutants in olive oil production countries. However, the knowledge about the in-situ effects of olive mill wastewaters to lotic ecosystems and their benthic organisms is very limited. To resolve this, eight sampling sites were selected upstream and downstream the outflow of several olive mills to assess the spatial and temporal effects of OMW to stream macroinvertebrates and to ecological status of stream ecosystems. Biotic (macroinvertebrates) and abiotic (physicochemical, hydromorphological) data were monitored for two years thus following the biennial cycle of olive growth and production and hydrological variation (drought-wet years). The results of this study revealed the spatial and temporal structural deterioration of the aquatic community due to OMW pollution with consequent reduction of the river capacity for reducing the effects of polluting substances through internal mechanisms of self-purification. OMW, even highly diluted, had dramatic impacts on the aquatic fauna and to the ecological status of the receiving stream ecosystems. The organic load of the wastewater expressed as BOD(5), COD and TSS, substrate contamination (sewage bacteria) and distance from the mill outlet, were the most important factors affecting macroinvertebrate assemblages while the typology (i.e. slope, altitude) and hydrology of the stream site (i.e. mountainous-lowland) and the intensity and volume of the wastewater were the most important determinants of self-purification processes. As OMW are usually being discharged in small size streams that are not considered in the Water Framework Directive 2000/60/EC, there is a need for including such systems into monitoring and assessment schemes as they may significantly contribute to the pollution load of the river basin. Furthermore, guidelines to manage these wastes through technologies that minimise their environmental impact and lead to a sustainable use

  14. Effect of fishing effort on catch rate and catchability of largemouth bass in small impoundments

    Science.gov (United States)

    Wegener, M. G.; Schramm, Harold; Neal, J. W.; Gerard, P.D.

    2018-01-01

    Largemouth bass Micropterus salmoides (Lacepède) catch rates decline with sustained fishing effort, even without harvest. It is unclear why declines in catch rate occur, and little research has been directed at how to improve catch rate. Learning has been proposed as a reason for declining catch rate, but has never been tested on largemouth bass. If catch rate declines because fish learn to avoid lures, periods of no fishing could be a management tool for increasing catch rate. In this study, six small impoundments with established fish populations were fished for two May to October fishing seasons to evaluate the effect of fishing effort on catch rate. Closed seasons were implemented to test whether a 2‐month period of no fishing improved catch rates and to determine whether conditioning from factors other than being captured reduced catch rate. Mixed‐model analysis indicated catch rate and catchability declined throughout the fishing season. Catch rate and catchability increased after a 2‐month closure but soon declined to the lowest levels of the fishing season. These changes in catch rate and catchability support the conclusion of learned angler avoidance, but sustained catchability of fish not previously caught does not support that associative or social learning affected catchability.

  15. Impacts of trout on aquatic macroinvertebrates in three Drakensberg ...

    African Journals Online (AJOL)

    Further studies are recommended in order to provide additional information on seasonal variation in these patterns, as well as on density-dependent effects of trout on aquatic macroinvertebrate communities. Keywords: management, Oncorhynchus mykiss, Salmo trutta, Ukhahlamba-Drakensberg Park, waterfalls

  16. Fish and macrozoobenthos in the Vlára stream drainage area (Bílé Karpaty Mountains)

    Czech Academy of Sciences Publication Activity Database

    Jurajda, Pavel; Adámek, Z.; Janáč, Michal; Valová, Zdenka

    2007-01-01

    Roč. 52, č. 7 (2007), s. 214-225 ISSN 1212-1819 R&D Projects: GA ČR GA524/04/1115 Grant - others:MZP(CZ) SE/620/12/03 Institutional research plan: CEZ:AV0Z60930519 Keywords : fish community * macroinvertebrates * bioindicators * Bílé Karpaty Mountains Subject RIV: EH - Ecology, Behaviour Impact factor: 0.633, year: 2007 http://journals.uzpi.cz:8050/uniqueFiles/00241.pdf/

  17. Small bowel perforation due to fish bone: A case report

    Directory of Open Access Journals (Sweden)

    Huseyin Pulat

    2015-09-01

    Full Text Available Accidental ingestion of foreign bodies are a common condition in clinical practice. However, small bowel perforation which dues to ingestion foreign bodies has been rarely seen. In this article, we report a case of small bowel perforation which dues to ingestion foreign body. A 80-year-old female patient, presenting with complaints of acute abdomen, was admitted to the emergency department. She denied abdominal pain, nausea and vomiting. The patient had tenderness and defense on the right lower quadrant. Contrast enhanced abdominal computed tomography has been used on the patient's diagnosis. This revealed small bowel perforation due to the ingestion of foreign body. The patient was operated emergency. A microperforation due to fish bone was detected on the terminal ileum. The patient underwent debridement and primary repair. The patient was discharged postoperative 7th day without problem. Bowel perforation due to the ingestion of foreign bodies should be considered in the differential diagnosis of acute abdomen. Keywords: Foreign body, Small intestine, Perforation

  18. Review of experimental and natural invertebrate hosts of sealworm (Pseudoterranova decipiens and its distribution and abundance in macroinvertebrates in eastern Canada

    Directory of Open Access Journals (Sweden)

    David J Marcogliese

    2001-11-01

    Full Text Available Experimental and natural invertebrate intermediate hosts of sealworm (Pseudoterranova decipiens as well as transmission experiments of sealworm from invertebrates to fish are reviewed and summarized. Experimental hosts include copepods, mysids, cumaceans, isopods, amphipods, decapods, annelids, and molluscs. Invertebrates collected from eastern Canada between 1989 and 1995 were checked for nematode infections by microscopic examination of dissected animals or enzymatic digestion of bulk samples. Third-stage larval sealworm were found in mysids (Neomysis americana, Mysis stenolepis from Passamaquoddy Bay, the Bras d’Or Lakes, inshore Cape Breton, Sable Island and Sable Island Bank. Infected amphipods (Amphiporeia virginiana, Americorchestia megalophthalma, Gammarus spp. were found only on Sable Island. Typical infection rates in macroinvertebrates were 1-4/1000. No sealworm infections were found in approximately 18,000 amphipods examined from Sable Island Bank, the site of the most heavily infected fishes in eastern Canada. In Wallace Lake, a brackish pond on Sable Island, infection rates were much higher in mysids than in amphipods. Estimates of rates of transmission of sealworm from invertebrates to fish were derived from infection levels in Wallace Lake and feeding experiments involving sticklebacks and invertebrate prey. It is concluded that mysids may be much more important than amphipods in transmitting sealworm to fish hosts.

  19. Are the effects of an invasive crayfish on lake littoral macroinvertebrate communities consistent over time?

    Directory of Open Access Journals (Sweden)

    Ruokonen T. J.

    2016-01-01

    Full Text Available Management of invasive species requires assessment of their effects on recipient ecosystems. However, impact assessment of invasive species commonly lacks a long-term perspective which can potentially lead to false conclusions. We examined the effects of the invasive signal crayfish (Pacifastacus leniusculus Dana on the stony littoral macroinvertebrate communities of a large boreal lake and assessed the extent to which the patterns observed in previous short-term studies were stable over time. We used temporal macroinvertebrate data collected in five consecutive years from a site with a well-established crayfish population, a site with no crayfish and a site where crayfish had been recently introduced. Our results revealed that signal crayfish had temporally rather consistent negative effects on the benthic macroinvertebrate assemblages but that the effects might be limited to certain taxa, in particular Gastropoda and Coleoptera. We also observed increases in Gastropoda density and taxa richness following a decline in crayfish density, indicating that the recovery of invertebrate assemblages might be fast. Hence, negative effects on benthic macroinvertebrates can likely be minimized by effective control of the signal crayfish population.

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

    International Nuclear Information System (INIS)

    Battaglia, M.; Hose, G.C.; Turak, E.; Warden, B.

    2005-01-01

    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

  1. Macroinvertebrate community change associated with the severity of streamflow alteration

    Science.gov (United States)

    Carlisle, Daren M.; Eng, Kenny; Nelson, S.M.

    2014-01-01

    Natural streamflows play a critical role in stream ecosystems, yet quantitative relations between streamflow alteration and stream health have been elusive. One reason for this difficulty is that neither streamflow alteration nor ecological responses are measured relative to their natural expectations. We assessed macroinvertebrate community condition in 25 mountain streams representing a large gradient of streamflow alteration, which we quantified as the departure of observed flows from natural expectations. Observed flows were obtained from US Geological Survey streamgaging stations and discharge records from dams and diversion structures. During low-flow conditions in September, samples of macroinvertebrate communities were collected at each site, in addition to measures of physical habitat, water chemistry and organic matter. In general, streamflows were artificially high during summer and artificially low throughout the rest of the year. Biological condition, as measured by richness of sensitive taxa (Ephemeroptera, Plecoptera and Trichoptera) and taxonomic completeness (O/E), was strongly and negatively related to the severity of depleted flows in winter. Analyses of macroinvertebrate traits suggest that taxa losses may have been caused by thermal modification associated with streamflow alteration. Our study yielded quantitative relations between the severity of streamflow alteration and the degree of biological impairment and suggests that water management that reduces streamflows during winter months is likely to have negative effects on downstream benthic communities in Utah mountain streams. 

  2. 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.

  3. Downstream effects of hydropower production on aquatic macroinvertebrate assemblages in two rivers in Costa Rica.

    Science.gov (United States)

    Chaves-Ulloa, Ramsa; Umaña-Villalobos, Gerardo; Springer, Monika

    2014-04-01

    Despite the fact that little is known about the consequences of hydropower production in tropical areas, many large dams (> 15 m high) are currently under construction or consideration in the tropics. We researched the effects of large hydroelectric dams on aquatic macroinvertebrate assemblages in two Costa Rican rivers. We measured physicochemical characteristics and sampled aquatic macroinvertebrates from March 2003 to March 2004 in two dammed rivers, Peñas Blancas and San Lorenzo, as well as in the undammed Chachagua River. Sites above and below the dam had differences in their physicochemical variables, with wide variation and extreme values in variables measured below the dam in the San Lorenzo River. Sites below the dams had reduced water discharges, velocities, and depths when compared with sites above the dams, as well as higher temperatures and conductivity. Sites above dams were dominated by collector-gatherer-scrapers and habitat groups dominated by swimmer-clingers, while sites below dams had a more even representation of groups. In contrast, a comparison between two sites at different elevation in the undammed river maintained a similar assemblage composition. Tributaries might facilitate macroinvertebrate recovery above the turbine house, but the assemblage below the turbine house resembled the one below the dam. A massive sediment release event from the dam decreased the abundance per sample and macroinvertebrate taxa below the dam in the Peñas Blancas River. Our study illustrates the effects of hydropower production on neotropical rivers, highlighting the importance of using multiple measures of macroinvertebrate assemblage structure for assessing this type of environmental impact.

  4. Small Marine Protected Areas in Fiji Provide Refuge for Reef Fish Assemblages, Feeding Groups, and Corals

    Science.gov (United States)

    Pires, Mathias M.; Guimarães, Paulo Roberto; Hoey, Andrew S.; Hay, Mark E.

    2017-01-01

    The establishment of no-take marine protected areas (MPAs) on coral reefs is a common management strategy for conserving the diversity, abundance, and biomass of reef organisms. Generally, well-managed and enforced MPAs can increase or maintain the diversity and function of the enclosed coral reef, with some of the benefits extending to adjacent non-protected reefs. A fundamental question in coral reef conservation is whether these benefits arise within small MPAs (fish assemblages, composition of fish feeding groups, benthic cover, and key ecosystem processes (grazing, macroalgal browsing, and coral replenishment) in three small (0.5–0.8 km2) no-take MPAs and adjacent areas where fisheries are allowed (non-MPAs) on coral reefs in Fiji. The MPAs exhibited greater species richness, density, and biomass of fishes than non-MPAs. Furthermore, MPAs contained a greater abundance and biomass of grazing herbivores and piscivores as well as a greater abundance of cleaners than fished areas. We also found differences in fish associations when foraging, with feeding groups being generally more diverse and having greater biomass within MPAs than adjacent non-MPAs. Grazing by parrotfishes was 3–6 times greater, and macroalgal browsing was 3–5 times greater in MPAs than in non-MPAs. On average, MPAs had 260–280% as much coral cover and only 5–25% as much macroalgal cover as their paired non-MPA sites. Finally, two of the three MPAs had three-fold more coral recruits than adjacent non-MPAs. The results of this study indicate that small MPAs benefit not only populations of reef fishes, but also enhance ecosystem processes that are critical to reef resilience within the MPAs. PMID:28122006

  5. Variation in Assemblages of Small Fishes and Microcrustaceans After Inundation of Rarely Flooded Wetlands of the Lower Okavango Delta, Botswana

    Science.gov (United States)

    Siziba, Nqobizitha; Chimbari, Moses J.; Masundire, Hillary; Mosepele, Ketlhatlogile; Ramberg, Lars

    2013-12-01

    Water extraction from floodplain river systems may alter patterns of inundation of adjacent wetlands and lead to loss of aquatic biodiversity. Water reaching the Okavango Delta (Delta), Botswana, may decrease due to excessive water extraction and climate change. However, due to poor understanding of the link between inundation of wetlands and biological responses, it is difficult to assess the impacts of these future water developments on aquatic biota. Large floods from 2009 to 2011 inundated both rarely and frequently flooded wetlands in the Delta, creating an opportunity to examine the ecological significance of flooding of wetlands with widely differing hydrological characteristics. We studied the assemblages of small fishes and microcrustaceans, together with their trophic relationships, in temporary wetlands of the lower Delta. Densities of microcrustaceans in temporary wetlands were generally lower than previously recorded in these habitats. Microcrustacean density varied with wetland types and hydrological phase of inundation. High densities of microcrustaceans were recorded in the 2009 to 2010 flooding season after inundation of rarely flooded sites. Large numbers of small fishes were observed during this study. Community structure of small fishes differed significantly across the studied wetlands, with poeciliids predominant in frequently flooded wetlands and juvenile cichlids most abundant in rarely flooded wetlands (analysis of similarity, P < 0.05). Small fishes of <20 mm fed largely on microcrustaceans and may have led to low microcrustacean densities within the wetlands. This result matched our prediction that rarely flooded wetlands would be more productive; hence, they supported greater populations of microcrustaceans and cichlids, which are aggressive feeders. However, the predominance of microcrustaceans in the guts of small fishes (<20 mm) suggests that predation by fishes may also be an important regulatory mechanism of microcrustacean

  6. Colonization by benthic macroinvertebrates in two artificial substrate types of a Riparian Forest

    Directory of Open Access Journals (Sweden)

    Lívia Borges dos Santos

    Full Text Available Abstract: Aim To analyze the efficiency of organic and inorganic substrates in samples of benthic macroinvertebrates of riparian forests from the Cerrado. Specific objectives (i characterize the ecological succession and taxonomic richness of benthic macroinvertebrates in stream affluent of a riparian forest; (ii analyze the influence of seasonality on the colonization of macroinvertebrates; and (iii determine the effect of the types of artificial substrates on the richness, composition and abundance of the benthic community. Methods Sampling was carried out in the rainy and dry seasons, and we installed in the watercourse two types of substrates: organic (leaf packs and inorganic (bricks, organized in pairs. Six samples per season were done to verify colonization, succession, richness and abundance of benthic community. The substrates were carefully sorted and the organisms were identified to the lowest possible taxonomic level. Results The ecological succession was clearly observed, with the initial occurrence of Chironomidae and Baetidae (considered early colonizers, and a late occurrence of organisms such as Helotrephidae and Trichoptera (considered late colonizers. No significant difference was found in the richness and abundance among the studied seasons (rainy and dry, but the organic substrate was significantly higher than the inorganic substrate for these parameters. Conclusion Organic artificial substrates are more efficient in characterizing the community of benthic macroinvertebrates in the study area, because they are more similar to the conditions of the substrate found naturally in the environment.

  7. Risk assessment of imidacloprid use in forest settings on the aquatic macroinvertebrate community.

    Science.gov (United States)

    Benton, Elizabeth P; Grant, Jerome F; Nichols, Rebecca J; Webster, R Jesse; Schwartz, John S; Bailey, Joseph K

    2017-11-01

    The isolated effects of a single insecticide can be difficult to assess in natural settings because of the presence of numerous pollutants in many watersheds. Imidacloprid use for suppressing hemlock woolly adelgid, Adelges tsugae (Annand) (Hemiptera: Adelgidae), in forests offers a rare opportunity to assess potential impacts on aquatic macroinvertebrates in relatively pristine landscapes. Aquatic macroinvertebrate communities were assessed in 9 streams in Great Smoky Mountains National Park (southern Appalachian Mountains, USA). The streams flow through hemlock conservation areas where imidacloprid soil drench treatments were applied for hemlock woolly adelgid suppression. Sites were located upstream and downstream of the imidacloprid treatments. Baseline species presence data (pre-imidacloprid treatment) were available from previous sample collections at downstream sites. Downstream and upstream sites did not vary in numerous community measures. Although comparisons of paired upstream and downstream sites showed differences in diversity in 7 streams, higher diversity was found more often in downstream sites. Macroinvertebrate functional feeding groups and life habits were similar between downstream and upstream sites. Downstream and baseline stream samples were similar. While some functional feeding group and life habit species richness categories varied, variations did not indicate poorer quality downstream communities. Imidacloprid treatments applied according to US Environmental Protection Agency federal restrictions did not result in negative effects to aquatic macroinvertebrate communities, which indicates that risks of imidacloprid use in forest settings are low. Environ Toxicol Chem 2017;36:3108-3119. © 2017 SETAC. © 2017 SETAC.

  8. Community structure of benthic macroinvertebrates inhabiting a highly stratified Mediterranean estuary

    Directory of Open Access Journals (Sweden)

    Alfonso Nebra

    2011-04-01

    Full Text Available The community composition and spatial distribution of benthic macroinvertebrates were studied along the Ebro estuary, a highly stratified estuary located in the NE Iberian Peninsula. During the last decade the oligotrophication process occurring in the lower Ebro River and its estuary has allowed a complex benthic macroinvertebrate community to become established; these results contrast with the poor community found there in the early nineties. A total of 214 taxa were identified, and polychaetes dominated the community both in abundance and species richness. The results showed spatial differences in the structure and composition of macroinvertebrates, which suggests that there are two distinct communities along the estuary. Each community was found in a specific stretch (upper and lower estuary in function of the presence of the salt wedge. The macrobenthos of the upper estuary was dominated by freshwater taxa, but some euryhaline species were also found. The lower estuary showed a marine community typical of shallow Mediterranean environments. The transition between these two communities fits an ecotone model. The highest abundances, richness and diversities were recorded at the lower estuarine stations, especially those closer to the river mouth, whereas the lowest values corresponded to the stations adjacent to the tip of the salt wedge.

  9. Effects of watershed and in-stream liming on macroinvertebrate communities in acidified tributaries to an Adirondack lake

    Science.gov (United States)

    George, Scott D.; Baldigo, Barry P.; Lawrence, Gregory B.; Fuller, Randall L.

    2018-01-01

    Liming techniques are being explored as a means to accelerate the recovery of aquatic biota from decades of acid deposition in many regions. The preservation or restoration of native sportfish populations has typically been the impetus for liming programs, and as such, less attention has been given to its effects on other biological assemblages such as macroinvertebrates. Furthermore, the differing effects of various lime application strategies such as in-stream and watershed applications are not well understood. In 2012, a program was initiated using in-stream and aerial (whole-watershed) liming to improve water quality and Brook Trout (Salvelinus fontinalis) recruitment in three acidified tributaries of a high-elevation Adirondack lake in New York State. Concurrently, macroinvertebrates were sampled annually between 2013 and 2016 at 3 treated sites and 3 untreated reference sites to assess the effects of each liming technique on this community. Despite improvements in water chemistry in all three limed streams, our results generally suggest that neither liming technique succeeded in improving the condition of macroinvertebrate communities. The watershed application caused an immediate and unsustained decrease in the density of macroinvertebrates and increase in the proportion of sensitive taxa. These changes were driven primarily by a one-year 71 percent reduction of the acid-tolerant Leuctra stoneflies and likely represent an initial chemistry shock from the lime application rather than a recovery response. The in-stream applications appeared to reduce the density of macroinvertebrates, particularly in one stream where undissolved lime covered the natural substrate. The close proximity of our study sites to the in-stream application points (50 and 1230 m) may partly explain these negative effects. Our results are consistent with prior studies of in-stream liming which indicate that this technique often fails to restore macroinvertebrate communities to a pre

  10. 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

  11. Comparison of two methods for estimating the abundance, diversity and habitat preference of fluvial macroinvertebrates in contrasting habitats

    NARCIS (Netherlands)

    Alonso, A.; Camargo, J.A.

    2010-01-01

    In this research we evaluate the effects of the method used for estimating the potential surface available for benthic macroinvertebrates in macrophyte and unvegetated habitats on several metrics and habitat preference of aquatic macroinvertebrates in the upper catchment of the Henares River

  12. Effects of oil pollution on aquatic macroinvertebrate assemblages in ...

    African Journals Online (AJOL)

    Macroinvertebrate assemblages from uncontaminated and contaminated sites in the Gamba Complex (Gabon) were compared, the latter sites having been subjected to ongoing oil spills since the 1970s. Vegetation communities surrounding the sites included savannah, shrub–scrub, palm forest, gallery forest and thick ...

  13. 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.

  14. Stream habitat structure influences macroinvertebrate response to pesticides

    International Nuclear Information System (INIS)

    Rasmussen, Jes Jessen; Wiberg-Larsen, Peter; Baattrup-Pedersen, Annette; Friberg, Nikolai; Kronvang, Brian

    2012-01-01

    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.

  15. Assessment of ecological quality of the Tajan river in Iran using a multimetric macroinvertebrate index and species traits

    NARCIS (Netherlands)

    Aazami, J.; Esmaili Sari, A.; Abdoli, A.; Sohrabi, H.; Brink, van den P.J.

    2015-01-01

    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

  16. Spatial and temporal distribution of benthic macroinvertebrates in a Southeastern Brazilian river.

    Science.gov (United States)

    Silveira, M P; Buss, D F; Nessimian, J L; Baptista, D F

    2006-05-01

    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.

  17. Water quality in Danube Delta Lakes: An assessment using benthic macroinvertebrates community

    Directory of Open Access Journals (Sweden)

    IBRAM Orhan

    2016-12-01

    Full Text Available An assessment of the ecological status of selected lakes in the Danube Delta Biosphere Reserve was done based on temporal and spatial variation of macroinvertebrate communities during 2012 and 2013. Macroinvertebrate communities and measures of these communities were evaluated and a baseline characterization of assemblages was determined for the analyzed sites. Each year, three sampling campaigns, one for each ice-free season were organized for data collection. Macroinvertebrate samples have been collected in every lake from three different stations with the use of an Ekmann dredge. The highest taxa richness are recorded in Fortuna and Isac lakes in 2013. Total abundance followed a pattern similar to taxa number with Fortuna and Isac lakes having the highest yearly values (maximum number of individuals – 225 - per sample has been recorded in September 2013, in Isac Lake.Using saprobic index as an indicator of ecological status Isac lake was classifies as moderate and other three lakes, Merhei, Furtuna and Rosu as good ecological status. Lack of correlation between diversity indices and the saprobic values suggests that other assessment methods could be more effective and provide better information than saprobic index does at least for Danube Delta.

  18. Effects of logging on macroinvertebrates in streams with and without buffer strips

    Energy Technology Data Exchange (ETDEWEB)

    Newbold, J D; Erman, D C; Roby, K B

    1980-01-01

    The impact of logging with and without buffer strip protection on stream macroinvertebrates was examined through comparisons of community structure in commercially logged and control watersheds throughout northern California. A nonparametric test of community dissimilarities within matched blocks of two control and one or two treated stations showed significant (P < 0.05) logging effects on unprotected streams when Euclidean distance and mutual information were used as dissimilarity indices, but not when chord distance was used. Shannon diversity in unprotected streams was lower (P < 0.01) than in control (unlogged) streams; densities of total macroinvertebrate fauna and of Chironomidae, Baetis, and Nemoura were higher in unprotected streams than in controls (P <0.05). Streams with narrow buffer strips (<30 m) showed significant effects by the Euclidean distance test, but diversity varied widely and was not significantly different from that in either unprotected or control streams than in controls (P < 0.05). Macroinvertebrate communities in streams with wide buffers (greater than or equal to 30m) could not be distinguished from those of controls by either Euclidean distance or diversity; however, diversity in wide-buffered streams was significantly greater than in streams without buffer strips, indicating effective protection from logging effects.

  19. Radio Tracking Fish with Small Unmanned Aircraft Systems (sUAS).

    Science.gov (United States)

    Dahlgren, R. P.; Anderson, K. R.; Hanson, L.; Pinsker, E. A.; Jonsson, J.; Chapman, D. C.; Witten, D. M.; O'Connor, K. A.

    2017-12-01

    Tracking radio tagged fish by boat or on foot in riverine systems is difficult and time consuming, particularly in large braided island complexes, shallow wetlands, and rocky reaches. Invasive Asian carp are commonly found in these hard to reach areas, but their near-surface feeding behavior makes radio tracking possible. To identify new methods of fish tracking that could same time and money, this study tested the feasibility of tracking Asian carp with Small Unmanned Aerial Systems (sUAS) in areas generally inaccessible to traditional tracking equipment. The U.S. Geological Survey worked with NanoElectromagnetics LLC and WWR Development to create and integrate a lightweight custom radio receiver, directional antenna, and accompanying software into a sUAS platform. The receiver includes independent GPS, software defined radio, and compass. The NASA Ames Research Center (ARC) completed payload integration, electromagnetic-interference and airworthiness testing, and provided a DJI Matrice 600 sUAS for this study. Additionally, ARC provided subject matter experts, airworthiness and flight readiness evaluation, and flight test facilities during preparation; and a pilot, range safety officer, and aircraft engineer during field deployment. Results demonstrate that this custom sUAS and sensor combination can detect radio tags at 100m above ground level and at horizontal ranges of 100m and 300m, with operators in either onshore or offshore locations. With this combination of sUAS and radio receiver, fish can be tracked in areas previously inaccessible and during flooding, providing new insights into riverine fish movement and habitat utilization.

  20. Aquatic macroinvertebrates associated with roots of Eichhornia azuera (Swarts Kunth (Pontederiaceae in an oxbow lake in Pantanal, MS

    Directory of Open Access Journals (Sweden)

    Hugo Henrique L. Saulino

    2014-09-01

    Full Text Available Macrophytes play an important role in the community structure of aquatic systems. In this study, we examined the macroinvertebrate communities within 20 Eichhornia azurea roots in an oxbow lake in Pantanal (MS during dry season. Species abundance and richness were compared via linear regression, and the mean relative proportion of macroinvertebrates among root samples was determined. Macroinvertebrates were identified to the lowest practical taxonomic level, and root volume was measured using the volume displacement method. We identified 371 specimens, belonging to 31 families and 21 taxonomic groups. Chironomus sp. (Chironomidae, Slavinia sp. and Dero sp. (Naididae, all detritivores, were most the represented taxon. Regression analysis indicated a positive correlation between root volume and the abundance and richness of the macroinvertebrate community. Analysis of variance showed no statistically significant differences between species abundance and richness among different E. azuera root volumes, however we did observe a trend toward a positive correlation of both variables with increasing root volume. We suspect that greater root volumes should increase microhabitat availability, which could explain this observed trend. Our results indicate that E. azurea roots may play an important ecologic role (e.g., by providing shelter, food stock in lake macroinvertebrate communities.

  1. Effects of Ecohydraulic Bank Stabilization Structures on Bank Stability and Macroinvertebrate Community in Surabaya River

    Directory of Open Access Journals (Sweden)

    Daru Setyo Rini

    2018-01-01

    Full Text Available There were 18 accelerated erosion sites identified along 7 km of Surabaya River Fishery Sanctuary Area. A model of ecohydraulic bank stabilization was applied to reduce bank erosion in Surabaya River at Gresik Regency Indonesia. The model is combination of reprofiled and revegetated bank with rock toe reinforcement and  addition of log groynes. Various native plant species were planted and naturally grown to establish multi-strata littoral vegetation structure. This study assessed effects of ecohydraulic bank stabilization on bank morphology, near bank velocity and littoral macroinvertebrate community during September 2014 to August 2016. The study found that rock toe enforcement, log groynes and reprofiled bank slope could stabilized the eroded bank, and littoral vegetation formation reduced near bank velocity at restored sites. There were 31 families of macroinvertebrate found in Surabaya River with high abundance of moderately pollution sensitive taxa Atyidae and pollution tolerant taxa Corixidae, Chironomidae and Tubificidae. The taxa richness, diversity index and abundance of sensitive and moderately sensitive macroinvertebrate group were increased after application of ecohydraulic bank stabilization at restored area. The results shown that ecohydraulic bank stabilization structure provides multi-benefits in improving bank stabilization against erosion and providing new micro-habitats for biotic community. Keywords:  ecohydraulic bank stabilization, macroinvertebrates, riparian restoration

  2. Protocols for collection of streamflow, water-quality, streambed-sediment, periphyton, macroinvertebrate, fish, and habitat data to describe stream quality for the Hydrobiological Monitoring Program, Equus Beds Aquifer Storage and Recovery Program, city of Wichita, Kansas

    Science.gov (United States)

    Stone, Mandy L.; Rasmussen, Teresa J.; Bennett, Trudy J.; Poulton, Barry C.; Ziegler, Andrew C.

    2012-01-01

    The city of Wichita, Kansas uses the Equus Beds aquifer, one of two sources, for municipal water supply. To meet future water needs, plans for artificial recharge of the aquifer have been implemented in several phases. Phase I of the Equus Beds Aquifer Storage and Recovery (ASR) Program began with injection of water from the Little Arkansas River into the aquifer for storage and subsequent recovery in 2006. Construction of a river intake structure and surface-water treatment plant began as implementation of Phase II of the Equus Beds ASR Program in 2010. An important aspect of the ASR Program is the monitoring of water quality and the effects of recharge activities on stream conditions. Physical, chemical, and biological data provide the basis for an integrated assessment of stream quality. This report describes protocols for collecting streamflow, water-quality, streambed-sediment, periphyton, macroinvertebrate, fish, and habitat data as part of the city of Wichita's hydrobiological monitoring program (HBMP). Following consistent and reliable methods for data collection and processing is imperative for the long-term success of the monitoring program.

  3. Benthic macroinvertebrate community of a fourth order stream in ...

    African Journals Online (AJOL)

    cinthia

    Full Length Research Paper. Benthic macroinvertebrate community of a fourth order stream in Kashmir Himalaya, India. Shazia Habib1* and A.R. Yousuf2. 1Department of Environmental Science, University of Kashmir, Srinagar, India. 2National Green Tribunal, Government of India, India. Received 31 December, 2013; ...

  4. Ecology of benthic macroinvertebrates in the depositional biotope of ...

    African Journals Online (AJOL)

    The ecology of benthic macroinvertebrates was studied in the depositional biotope of a river in southern Nigeria in two contrasting tidally influenced fresh and brackish water stations. Forty five taxa in nineteen families representing seven major groups of benthos were recorded. The molluscan families, dominated by ...

  5. Benthic Macroinvertebrate Communities in the Northern Tributaries of the “Iron Gates” Gorge (Danube River

    Directory of Open Access Journals (Sweden)

    Curtean-Bănăduc Angela

    2014-12-01

    Full Text Available The paper presents the structure of the benthonic macro-invertebrates communities in the Berzasca, Sirinia, Liubcova, and Mraconia rivers. The results are based on quantitative benthos samples (95 samples, collected in July 2014 from 19 sampling stations within the study area. In longitudinal profile, the benthonic macro-invertebrate communities of the Sirinia, Liubcova and Berzasca rivers displays relatively large structural variability, while the communities of the Mraconia River displays smaller structural variability. The structure of the benthonic macro-invertebrate communities correlated with the biotope characteristics indicates the good ecological status of the analysed rivers, with the exception of the Berzasca River sector downstream of the town of Berzasca and immediately upstream of the Danube junction, a sector with moderate ecological status due to negative effects from man-made modifications in the lotic biotope of the sector.

  6. Effects of barge traffic on distribution and survival of ichthyoplankton and small fishes in the upper Mississippi River

    Science.gov (United States)

    Holland, L.E.

    1986-01-01

    Short-term impacts of commercial barge traffic on fish eggs, larvae, young-of-the-year (age-0) fishes, and small adults in the main channel of the upper Mississippi River were examined. Barge passages caused significant changes in the distribution of eggs and larvae in the study area. The mean catch of ichthyoplankton was reduced in both surface and bottom waters for 90 min after passage of vessels downstream. The effects of upstream traffic on catch ranged from nil in surface or bottom samples to short-term increases in surface samples immediately after passage. No consistent effect on the catch of age-0 or small adult fishes in surface or bottom trawls was evident.

  7. A relative contribution of carbon from green tide algae Cladophora glomerata and Ulva intestinalis in the coastal food webs in the Neva Estuary (Baltic Sea).

    Science.gov (United States)

    Golubkov, Sergey M; Berezina, Nadezhda A; Gubelit, Yulia I; Demchuk, Anna S; Golubkov, Mikhail S; Tiunov, Alexei V

    2018-01-01

    We analyzed stable isotope composition of carbon and nitrogen of suspended organic matter (seston) and tissues of macroalgae, macroinvertebrates and fish from the coastal area of the highly eutrophic Neva Estuary to test a hypothesis that organic carbon of macroalgae Cladophora glomerata and Ulva intestinalis produced during green tides may be among primary sources supporting coastal food webs. The Stable Isotope Bayesian mixing model (SIAR) showed that consumers poorly use organic carbon produced by macroalgae. According to the results of SIAR modeling, benthic macroinvertebrates and fish mostly rely on pelagic derived carbon as a basal resource for their production. Only some species of macroinvertebrates consumed macroalgae. Fish used this resource directly consuming zooplankton or indirectly via benthic macroinvertebrates. This was consistent with the results of the gut content analysis, which revealed a high proportion of zooplankton in the guts of non-predatory fish. Copyright © 2017. Published by Elsevier Ltd.

  8. Effects of local land-use on riparian vegetation, water quality, and the functional organization of macroinvertebrate assemblages.

    Science.gov (United States)

    Fierro, Pablo; Bertrán, Carlos; Tapia, Jaime; Hauenstein, Enrique; Peña-Cortés, Fernando; Vergara, Carolina; Cerna, Cindy; Vargas-Chacoff, Luis

    2017-12-31

    Land-use change is a principal factor affecting riparian vegetation and river biodiversity. In Chile, land-use change has drastically intensified over the last decade, with native forests converted to exotic forest plantations and agricultural land. However, the effects thereof on aquatic ecosystems are not well understood. Closing this knowledge gap first requires understanding how human perturbations affect riparian and stream biota. Identified biological indicators could then be applied to determine the health of fluvial ecosystems. Therefore, this study investigated the effects of land-use change on the health of riparian and aquatic ecosystems by assessing riparian vegetation, water quality, benthic macroinvertebrate assemblages, and functional feeding groups. Twenty-one sites in catchment areas with different land-uses (i.e. pristine forests, native forests, exotic forest plantations, and agricultural land) were selected and sampled during the 2010 to 2012 dry seasons. Riparian vegetation quality was highest in pristine forests. Per the modified Macroinvertebrate Family Biotic Index for Chilean species, the best conditions existed in native forests and the worst in agricultural catchments. Water quality and macroinvertebrate assemblages significantly varied across land-use areas, with forest plantations and agricultural land having high nutrient concentrations, conductivity, suspended solids, and apparent color. Macroinvertebrate assemblage diversity was lowest for agricultural and exotic forest plantation catchments, with notable non-insect representation. Collector-gatherers were the most abundant functional feeding group, suggesting importance independent of land-use. Land-use areas showed no significant differences in functional feeding groups. In conclusion, anthropogenic land-use changes were detectable through riparian quality, water quality, and macroinvertebrate assemblages, but not through functional feeding groups. These data, particularly the

  9. Benthic macroinvertebrates as bioindicators of water quality in Billings Reservoir fishing sites (SP, Brazil

    Directory of Open Access Journals (Sweden)

    José Ricardo Baroldi Ciqueto Gargiulo

    Full Text Available Abastract: Aim The Billings Reservoir is the largest reservoir in the metropolitan region of São Paulo and has multiple uses, including artisanal fishing. Its surroundings present intense occupation, resulting in various environmental impacts. Although the water is degraded, affecting the composition and quality of the fish, this reservoir supports artisanal fishermen who survive through this activity. This study aimed to analyze the water quality in the main sites of artisanal fishing activity, with an emphasis on the benthic community as a bioindicator. Methods Three sampling sites were selected, in which water and zoobenthos samples were collected monthly from April 2012 to March 2013. Water analyses consisted of the determination of pH, temperature, conductivity, turbidity, total dissolved solids, dissolved oxygen, total nitrogen, total phosphorus, and trophic state as well as a principal components analysis. The zoobenthos analysis consisted of determining the relative abundance and total density of taxa, the Shannon-Weaver diversity index, taxa richness, uniformity, Simpson’s dominance index, and the benthic community index and conducting a canonical correspondence analysis. The non-parametric Kruskal-Wallis test followed by the Student-Newman-Keuls test were used to investigate the existence of significant differences in the abiotic and biotic variables among the sites. Results The studied sites showed a high degree of eutrophication, with nitrogen and phosphorus totals levels above the limits defined by current Brazilian legislation. Taquacetuba (P1 showed the best environmental conditions for the development of fishing activity, with the presence of sensitive organisms (Polymitarcyidae and higher levels of dissolved oxygen. Alvarenga (P2 had the worst water quality, with a predominance of tolerant organisms (Oligochaeta and lower levels of dissolved oxygen. Conclusion In conclusion, the benthic community in association with abiotic

  10. Assessment of the ecological potential of mine-water treatment wetlands using a baseline survey of macroinvertebrate communities

    International Nuclear Information System (INIS)

    Batty, L.C.; Atkin, L.; Manning, D.A.C.

    2005-01-01

    A baseline survey of macroinvertebrate populations in two mine-water treatment wetlands, one treating a net acidic spoil heap discharge and one a net alkaline ferruginous pumped mine water, was undertaken to assess the potential of these systems to provide habitats for faunal communities. Both wetlands were found to be impoverished in comparison to natural wetlands but did sustain a macroinvertebrate community that could support higher organisms. Wetland size and water quality in terms of pH, conductivity and metal concentrations were found to be important factors in determining the quality of the populations supported. Direct toxicity to organisms was unlikely to be the main cause of lower diversity, but the smothering of organisms via the precipitation of iron hydroxides particularly in the early parts of the treatment systems affected macroinvertebrate communities. The presence of areas of open water within the planted systems was found to be important for providing habitats for macroinvertebrates and this should be both a future design and maintenance consideration for environmental managers. - Mine-water treatment wetlands can be engineered to provide habitats for ecological communities

  11. 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.

  12. Low-cost small action cameras in stereo generates accurate underwater measurements of fish

    OpenAIRE

    Letessier, T. B.; Juhel, Jean-Baptiste; Vigliola, Laurent; Meeuwig, J. J.

    2015-01-01

    Small action cameras have received interest for use in underwater videography because of their low-cost, standardised housing, widespread availability and small size. Here, we assess the capacity of GoPro action cameras to provide accurate stereo-measurements of fish in comparison to the Sony handheld cameras that have traditionally been used for this purpose. Standardised stereo-GoPro and Sony systems were employed to capture measurements of known-length targets in a pool to explore the infl...

  13. Fishing activity in Northern Rio de Janeiro State (Brazil and its relation with small cetaceans

    Directory of Open Access Journals (Sweden)

    Ana Paula Madeira Di Beneditto

    1998-01-01

    Full Text Available Research on fishing activity at Atafona village, in Northern Rio de Janeiro, Brazil (21°35'S, was carried out between 1987-96 for the purpose of relating it to the accidental capture of small cetaceans and of estimating the relationship between fishing activity and the diet of small cetaceans. Data on fishing operations were obtained at the cold storage plants management, from interviews with fishermen and personal observations. The most representative fishing resources were Xyphopenaeus kroyeri, Micropogonias furnieri, Carcharhinus plumbeus, C. acronotus,and Rhizoprionodon porosus. Gillnets are responsible for the accidental capture of small cetaceans in the region, mainly Pontoporia blainvillei and Sotalia fluviatilis (marine form. Four types of gillnets that are used on the region ("minjuada", "sarda", "caçoá" and "pescadinha" were dangerous to these species because they are placed in their preferred habitat. There is no competition between fishermen and small cetaceans due to the selection in the capture of commercialized fishesInvestigação sobre a atividade pesqueira na localidade de Atafona, Norte do Rio de Janeiro, Brasil (21º25`S, foi conduzida entre 1987-96 com o objetivo de relacioná-la com a captura acidental e a dieta dos pequenos cetáceos. Dados sobre as operações pesqueiras foram obtidos na administração dos entrepostos de pesca, através de entrevistas com pescadores e observações pessoais. Os recursos pesqueiros mais representativos foram Xyphopenaeus kroyeri, Micropogonias furnieri, Carcharhinus plumbeus, C. acronotus, and Rhizoprionodon porosus. As redes de espera são responsáveis pela captura acidental de pequenos cetáceos na região, principalmente de Pontoporia blainvillei e Sotalia fluviatilis (forma marinha. Quatro tipos de redes de espera que são usadas na região ("minjuada", "sarda", "caçoá" and "pescadinha" foram mais perigosas para essas espécies pois são colocadas no seu hábitat preferencial

  14. Species-specific impacts of a small marine reserve on reef fish production and fishing productivity in the Turks and Caicos Islands

    NARCIS (Netherlands)

    Tupper, M.H.; Rudd, M.A.

    2002-01-01

    Marine reserves are widely considered to potentially benefit reef fisheries through emigration, yet the empirical basis for predicting the extent of this for small reserves is weak. The effects of fishing pressure and habitat on biomass and catch per unit effort (CPUE) of three species of exploited

  15. The efficacy of clove oil as an anaesthetic and in euthanasia procedure for small-sized tropical fishes.

    Science.gov (United States)

    Fernandes, I M; Bastos, Y F; Barreto, D S; Lourenço, L S; Penha, J M

    2017-01-01

    Clove oil is used as a fish anesthetic because it is a natural and inexpensive product with low toxicity risks. The goal of the present study was to determine the appropriate concentration of clove oil for small-sized tropical fish to be used in mark-recapture studies or when individuals are to be sacrificed. We applied three different clove oil concentrations (D1=0.05 mL, D2=0.10 mL and D3=0.20 mL per 500 mL of water) on three small-sized fish species. We found a negative relationship between induction time and treatment for two species (Hyphessobrycon sp.1 and Hemigrammus sp.), while concentration was unrelated to recovery time. Fish body length was positively related to induction time in the D2 treatment for Hemigrammus sp., and negatively for Hyphessobrycon sp.1 in the D1 treatment, but was unrelated to recovery time for three species and treatments. Mortality rates varied across treatments, but higher rates were observed with higher clove oil concentrations. We conclude that 0.05 mL of clove oil per 500 mL of water is the most efficient dose for studies where fish will be released back to their natural habitats, while 0.20 mL of clove oil is recommended for studies that require fish euthanization for further laboratory analyses.

  16. 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

  17. Impact of Urban Effluents on the Macroinvertebrates of a Creek in ...

    African Journals Online (AJOL)

    User

    The impact of effluents on the macroinvertebrate communities of an urban creek in ... of complying with the Environmental Protection Agency (EPA) guidelines are ..... Business. World Water Council, Earthscan. Publications Ltd. London, UK.

  18. Assessing condition of macroinvertebrate communities and sediment toxicity in the St. Lawrence River at Massena Area-of-Concern

    Science.gov (United States)

    Duffy, Brian T.; Baldigo, Barry P.; Smith, Alexander J.; George, Scott D.; David, Anthony M.

    2016-01-01

    In 1972, the USA and Canada agreed to restore the chemical, physical, and biological integrity of the Great Lakes ecosystem under the first Great Lakes Water Quality Agreement. In subsequent amendments, part of the St. Lawrence River at Massena, New York and segments of three tributaries, were designated as an Area of Concern (AOC) due to the effects of polychlorinated biphenyls (PCBs), lead and copper contamination, and habitat degradation and resulting impairment to several beneficial uses. Because sediments have been largely remediated, the present study was initiated to evaluate the current status of the benthic macroinvertebrate (benthos) beneficial use impairment (BUI). Benthic macroinvertebrate communities and sediment toxicity tests using Chironomus dilutus were used to test the hypotheses that community condition and sediment toxicity at AOC sites were not significantly different from those of adjacent reference sites. Grain size was found to be the main driver of community composition and macroinvertebrate assemblages, and bioassessment metrics did not differ significantly between AOC and reference sites of the same sediment class. Median growth of C. dilutus and its survival in three of the four river systems did not differ significantly in sediments from AOC and reference sites. Comparable macroinvertebrate assemblages and general lack of toxicity across most AOC and reference sites suggest that the quality of sediments should not significantly impair benthic macroinvertebrate communities in most sites in the St. Lawrence River AOC.

  19. Three new Species and six new Records of small Serranoid Fishes from Curaçao and Puerto Rico

    NARCIS (Netherlands)

    Randall, John E.

    1963-01-01

    Among the fishes taken during a recent collecting trip to Curaçao are three very colorful small serranoids which represent undescribed species. Two of the three new fishes are grammids of the previously monotypic genus Lipogramma, and their discovery necessitates a slight modification of the generic

  20. Patterning and predicting aquatic macroinvertebrate diversities using artificial neural network

    NARCIS (Netherlands)

    Park, Y.S.; Verdonschot, P.F.M.; Chon, T.S.; Lek, S.

    2003-01-01

    A counterpropagation neural network (CPN) was applied to predict species richness (SR) and Shannon diversity index (SH) of benthic macroinvertebrate communities using 34 environmental variables. The data were collected at 664 sites at 23 different water types such as springs, streams, rivers,

  1. Assessing the Effects of Hydromorphological Degradation on Macroinvertebrate Indicators in Rivers: Examples, Constraints and Outlook

    DEFF Research Database (Denmark)

    Friberg, N.; Sandin, L.; Pedersen, Morten Lauge

    2009-01-01

    data of 28 Swedish streams, whereas moderate (R2 0.43) relationships with more detailed measurements of morphology were found in 2 Danish studies (39 and 6 streams, respectively). Although evidence exists in the literature on the importance of physical features for in-stream biota in general......) scaling issues (spatial and temporal) when relating habitat surveys to macroinvertebrate assessments, and 3) the scope of commonly used macroinvertebrate assessment systems (mainly focusing on water chemistry perturbation, such as eutrophication and acidification). The need is urgent to develop refined......An extensive amount of literature on linkages between the in-stream physical environment and river benthic macroinvertebrates reports a number of relationships across multiple spatial scales. We analyzed data on different spatial scales to elucidate the linkages between different measurements...

  2. 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.

  3. The Value of the Freshwater Snail Dip Scoop Sampling Method in Macroinvertebrates Bioassessment of Sugar Mill Wastewater Pollution in Mbandjock, Cameroon

    Directory of Open Access Journals (Sweden)

    Emmanuel Noumi

    2008-03-01

    Full Text Available Macroinvertebrates identification and enumeration may be used as a simple and affordable alternative to chemical analysis in water pollution monitoring. However, the ecological responses of various taxa to pollution are poorly known in resources-limited tropical countries. While freshwater macroinvertebrates have been used in the assessment of water quality in Europe and the Americas, investigations in Africa have mainly focused on snail hosts of human parasites. There is a need for sampling methods that can be used to assess both snails and other macroinvertebrates. The present study was designed to evaluate the usefulness of the freshwater snail dip scoop method in the study of macroinvertebrates for the assessment of the SOSUCAM sugar mill effluents pollution. Standard snail dip scoop samples were collected upstream and downstream of the factory effluent inputs, on the Mokona and Mengoala rivers. The analysis of the macroinvertebrate communities revealed the absence of Ephemeroptera and Trichoptera, and the thriving of Syrphidae in the sections of the rivers under high effluent load. The Shannon and Weaver diversity index was lower in these areas. The dip scoop sampling protocol was found to be a useful method for macroinvertebrates collection. Hence, this method is recommended as a simple, cost-effective and efficient tool for the bio-assessment of freshwater pollution in developing countries with limited research resources.

  4. Aquatic macroinvertebrates and water quality of Sandia Canyon, Los Alamos National Laboratory, November 1993--October 1994

    Energy Technology Data Exchange (ETDEWEB)

    Cross, S.

    1995-08-01

    The Ecological Studies Team (EST) of ESH-20 at Los Alamos National Laboratory (LANL) has collected samples from the stream within Sandia Canyon since the summer of 1990. These field studies gather water quality measurements and collect aquatic macroinvertebrates from permanent sampling sites. Reports by Bennett (1994) and Cross (1994) discuss previous EST aquatic studies in Sandia Canyon. This report updates and expands those findings. EST collected water quality data and aquatic macroinvertebrates at five permanent stations within the canyon from November 1993 through October 1994. The two upstream stations are located below outfalls that discharge industrial and sanitary waste effluent into the stream, thereby maintaining year-round flow. Some water quality parameters are different at the first three stations from those expected of natural streams in the area, indicating degraded water quality due to effluent discharges. The aquatic habitat at the upper stations has also been degraded by sedimentation and channelization. The macroinvertebrate communities at these stations are characterized by low diversities and unstable communities. In contrast, the two downstream stations appear to be in a zone of recovery, where water quality parameters more closely resemble those found in natural streams of the area. The two lower stations have increased macroinvertebrate diversity and stable communities, further indications of downstream water quality improvement.

  5. Ecological impact assessment of sediment remediation in a metal-contaminated lowland river using translocated zebra mussels and resident macroinvertebrates.

    Science.gov (United States)

    De Jonge, M; Belpaire, C; Geeraerts, C; De Cooman, W; Blust, R; Bervoets, L

    2012-12-01

    The present study investigated to what extent accumulated metal levels in aquatic invertebrates can reflect environmental contamination and how these tissue levels can be related to alterations in macroinvertebrate communities in the dredged River Dommel. Metal accumulation was measured in translocated zebra mussels (Dreissena polymorpha) and resident Chironomidae. Furthermore, macroinvertebrate community composition was assessed. Our results indicated that trends of total metal concentrations in surface water of the Dommel in time are reflected well by metal levels in tissue of D. polymorpha. In contrast, sediment-bound metals were the most dominant exposure route for Chironomidae. Alterations in macroinvertebrate community composition were observed during dredging and significant relations between metal levels in invertebrate tissues and ecological responses were found. Our results demonstrated that metal accumulation in both zebra mussels and Chironomidae can be used as an integrated measure of metal bioavailability and to predict ecological effects of metal toxicity on macroinvertebrate communities. Copyright © 2012 Elsevier Ltd. All rights reserved.

  6. Assessing the ecological status of the Cisadane River’s headwaters using benthic macroinvertebrates

    Science.gov (United States)

    Krisanti, M.; Wardiatno, Y.; Anzani, Y. M.

    2017-01-01

    Benthic macroinvertebrates are commonly used in river health biomonitoring. In monitoring program biotic indices are now widely established in water quality monitoring around the world, including in the tropical countries. The aim of this study was to reveal the ecological status of Cisadane River’s headwaters in inside and outside of Mount Halimun-Salak National Park by using benthic macroinvertebrates. The research was conducted in the headwaters of Cisadane River located in Mount Halimun-Salak National Park. Macroinvertebrates were collected from four sites, i.e. inside the park (station 1, 2, 3, and 4) and from two sites outside the park (station 5 and 6). Collections were made twice a month, starting from April to June 2015 by means of Surber sampler (frame area 30x30 cm). A total of 65 genera from 38 families and 11 orders were found in the river. The results showed that based on diversity index, Lincoln Quality Index (LQI), Family Biotic Index (FBI), and Stream Invertebrate Grade Number Average Level 2 (SIGNAL 2), stations located within national park were ecologically better than those outside national park. Rivers with well-preserved riverside vegetation, as in the national park area have greater ecological status.

  7. Efficiency of Pollution Tolerance Index (PTI of macroinvertebrates in detecting aquatic pollution in an oxbow lake in India

    Directory of Open Access Journals (Sweden)

    Dipankar Ghosh

    2017-11-01

    Full Text Available This paper evaluates the efficiency of a macroinvertebrate-based Pollution Tolerance Index (PTI in detecting aquatic pollution in the Chhariganga oxbow lake in India. In this lake, calculated PTIs were compared with results from an array of physicochemical water and sediment parameters and to a macroinvertebrate diversity assessment conducted in parallel for the same lake. The obtained PTI values fell in a range (between 20 and 31 that are indicative of an absence of organic pollution according to the literature, and are normally reported for systems devoid of anthropogenic activity (for instance no monsoonal polluting jute retting activities. However, in the light of the results for the assessed water and sediment physicochemical parameters, and the support of diversity indexes of macroinvertebrates, using data from the same lake, it was possible to conclude that the obtained PTI values do not reflect the true pollution status of this oxbow lake. As PTI values and diversity indexes contradict each other in detecting pollution, it is advised to take both parameters into consideration when using macroinvertebrates to assess aquatic health.

  8. Benthic Macroinvertebrate Assemblages in the Near Coastal Zone of Lake Erie

    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...

  9. The influence of connectivity in forest patches, and riparian vegetation width on stream macroinvertebrate fauna

    Directory of Open Access Journals (Sweden)

    IC Valle

    Full Text Available We assessed two dimensions of stream connectivity: longitudinal (between forest patches along the stream and lateral (riparian vegetation, using macroinvertebrate assemblages as bioindicators. Sites representing different land-uses were sampled in a lowland basin that holds a mosaic of protected areas. Land-use analysis, forest successional stages and riparian zone widths were calculated by the GIS analysis. Macroinvertebrate fauna was strongly affected by land-use. We observed a continuous decrease in the number of sensitive species, %Shredders and IBE-IOC biotic index from the upstream protected area to highly deforested sites, increasing again where the stream crosses a Biological Reserve. When analysing buffer strips, we found aquatic fauna responding to land-use alterations beyond the 30 m riparian corridor (60 m and 100 m wide. We discussed the longitudinal connectivity between forest patches and the riparian vegetation buffer strips necessary to hold high macroinvertebrate diversity. We recommend actions for the increase/maintenance of biodiversity in this and other lowland basins.

  10. Temporal change in biological community structure in the Fountain Creek basin, Colorado, 2001-2008

    Science.gov (United States)

    Zuellig, Robert E.; Bruce, James F.; Stogner, Sr., Robert W.

    2010-01-01

    variable subsets that were significantly correlated with temporal change in the macroinvertebrate and fish community structure. Other important environmental variables related to temporal change in the biological community structure included those describing channel form (streambank height) and streamflow (normalized annual mean daily flow, high flood-pulse count). Site-specific results from this study were derived from a relatively small number of observations (6 or 8 years of data); therefore, additional years of data may reveal other sites with temporal change in biological community structure, or could define stronger and more consistent linkages between environmental variables and observed temporal change. Likewise current variable subsets could become weaker. Nonetheless, there were several sites where temporal change was detected in this study that could not be explained by the available environmental variables studied herein. Modification of current data-collection activities may be necessary to better understand site-specific temporal relations between biological communities and environmental variables.

  11. Workflow for the Targeted and Untargeted Detection of Small Metabolites in Fish Skin Mucus

    Directory of Open Access Journals (Sweden)

    Lada Ivanova

    2018-06-01

    Full Text Available The skin mucus of fish is in permanent contact with the aquatic environment. Data from the analysis of the chemical composition of skin mucus could potentially be used for monitoring the health status of the fish. Knowledge about mucus composition or change in composition over time could also contribute to understanding the aetiology of certain diseases. The objective of the present study was the development of a workflow for non-invasive sampling of skin mucus from farmed salmon (Salmo salar for the targeted and untargeted detection of small metabolites. Skin mucus was either scraped off, wiped off using medical wipes, or the mucus’ water phase was absorbed using the same type of medical wipes that was used for the wiping method. Following a simple filtration step, the obtained mucus samples were subjected to hydrophilic interaction chromatography coupled to high-resolution mass spectrometry. Post-acquisition processing included the targeted analysis of 86 small metabolites, of which up to 60 were detected in absorbed mucus. Untargeted analysis of the mucus samples from equally treated salmon revealed that the total variation of the metabolome was lowest in absorbed mucus and highest in the scraped mucus. Thus, future studies including small-molecule metabolomics of skin mucus in fish would benefit from a sampling regime employing absorption of the water phase in order to minimize the bias related to the sampling step. Furthermore, the absorption method is also a less invasive approach allowing for repetitive sampling within short time intervals.

  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.

  13. Cascade-pond System Health Assessment Based on Macroinvertebrate Indices and Its Relationship with Impervious Cover and Aquatic Buffer Zone in Urbanized Catchments

    Directory of Open Access Journals (Sweden)

    Zulkarnain Faris

    2017-01-01

    Full Text Available A cascade-pond system consists of six ponds located at Universitas Indonesia Campus, Depok. Its catchment area is dominated by high density urban area with moderate to high imperviousness. Some of riparian buffers surrounds six ponds are also occupied by high imperviousness that may lead some ecohydrological problems i.e. water quality degradation, declining freshwater biodiversity and food web changes. The aim of this study is assessing the current state of cascade-pond system health. The assessment of macroinvertebrate indices is based on SingScore that have been developed by Public Utilities Board of Singapore for macroinvertebrate biotic index. Impervious cover data is obtained from high-resolution imageries and processed using ArcGIS 10.5. Qualitative statistics methods, Chi-squared test describes the relationship of macroinvertebrate indices with catchment area imperviousness and aquatic buffer zone. The health assessment based on macroinvertebrates indices shows that the lower ponds are relatively healthier than the upper one. There is also any significant relationship between macroinvertebrate indices with impervious cover based on chi square test and cross tabulation analysis.

  14. Occupational Safety and Health Conditions Aboard Small- and Medium-Size Fishing Vessels: Differences among Age Groups.

    Science.gov (United States)

    Zytoon, Mohamed A; Basahel, Abdulrahman M

    2017-02-24

    Although marine fishing is one of the most hazardous occupations, research on the occupational safety and health (OSH) conditions aboard marine fishing vessels is scarce. For instance, little is known about the working conditions of vulnerable groups such as young and aging fishermen. The objective of the current paper is to study the OSH conditions of young and aging fishermen compared to middle-aged fishermen in the small- and medium-size (SM) marine fishing sector. A cross-sectional study was designed, and 686 fishermen working aboard SM fishing vessels were interviewed to collect information about their safety and health. The associations of physical and psychosocial work conditions with safety and health outcomes, e.g., injuries, illnesses and job satisfaction, are presented. The results of the current study can be utilized in the design of effective accident prevention and OSH training programs for the three age groups and in the regulation of working conditions aboard fishing vessels.

  15. Surf zone fish diet as an indicator of environmental and anthropogenic influences

    Science.gov (United States)

    Costa, Leonardo Lopes; Zalmon, Ilana Rosental

    2017-10-01

    Changes in species' abundance have been used as indicators of environmental and anthropogenic disturbances. However, sublethal, e.g., diet, changes should be detected before some alterations in the composition and structure of fish assemblages occur as a result of ecological negative impacts. The objective of the present study was to assess possible changes in surf zone fish diet in response to environmental and anthropogenic disturbances. Surf zone fish were sampled and their stomach contents were analyzed on two sandy beaches under different levels of human pressure in Southeastern Brazil. Habitat variables related to seasonality, food availability, anthropogenic disturbance, upwelling and river influence were measured as follows: (1) wave height; (2) water temperature; (3) intertidal macroinvertebrates abundance; (4) solid waste amount; (5) salinity; (6) particulate organic carbon (POC) and (7) chlorophyll a (Chl a). Our results showed the influence of seasonality, prey abundance and hydrodynamics in prey selection, and diet overlap between typical surf zone residents. A literature search was also performed and it shows that insects and Emerita brasiliensis eggs, which were the main food item consumed by some surf zone fish at urbanized Brazilian beaches, are unusual worldwide. Furthermore, solid waste was related to high consumption of insects by pompanos fish in urbanized areas, suggesting that this fish diet could be a sublethal indicator of human impact on sandy beaches.

  16. Macroinvertebrate short-term responses to flow variation and oxygen depletion: A mesocosm approach.

    Science.gov (United States)

    Calapez, Ana R; Branco, Paulo; Santos, José M; Ferreira, Teresa; Hein, Thomas; Brito, António G; Feio, Maria João

    2017-12-01

    In Mediterranean rivers, water scarcity is a key stressor with direct and indirect effects on other stressors, such as water quality decline and inherent oxygen depletion associated with pollutants inputs. Yet, predicting the responses of macroinvertebrates to these stressors combination is quite challenging due to the reduced available information, especially if biotic and abiotic seasonal variations are taken under consideration. This study focused on the response of macroinvertebrates by drift to single and combined effects of water scarcity and dissolved oxygen (DO) depletion over two seasons (winter and spring). A factorial design of two flow velocity levels - regular and low (vL) - with three levels of oxygen depletion - normoxia, medium depletion (dM) and higher depletion (dH) - was carried out in a 5-artificial channels system, in short-term experiments. Results showed that both stressors individually and together had a significant effect on macroinvertebrate drift ratio for both seasons. Single stressor effects showed that macroinvertebrate drift decreased with flow velocity reduction and increased with DO depletion, in both winter and spring experiments. Despite single stressors opposing effects in drift ratio, combined stressors interaction (vL×dM and vL×dH) induced a positive synergistic drift effect for both seasons, but only in winter the drift ratio was different between the levels of DO depletion. Stressors interaction in winter seemed to intensify drift response when reached lower oxygen saturation. Also, drift patterns were different between seasons for all treatments, which may depend on individual's life stage and seasonal behaviour. Water scarcity seems to exacerbate the oxygen depletion conditions resulting into a greater drifting of invertebrates. The potential effects of oxygen depletion should be evaluated when addressing the impacts of water scarcity on river ecosystems, since flow reductions will likely contribute to a higher oxygen

  17. Results of Macroinvertebrate Sampling Conducted at 33 SRS Stream Locations, July--August 1993

    Energy Technology Data Exchange (ETDEWEB)

    Specht, W.L.

    1994-12-01

    In order to assess the health of the macroinvertebrate communities of SRS streams, the macroinvertebrate communities at 30 stream locations on SRS were sampled during the summer of 1993, using Hester-Dendy multiplate samplers. In addition, three off-site locations in the Upper Three Runs drainage were sampled in order to assess the potential for impact from off-site activities. In interpreting the data, it is important to recognize that these data were from a single set of collections. Macroinvertebrate communities often undergo considerable temporal variation, and are also greatly influenced by such factors as water depth, water velocity, and available habitat. These stations were selected with the intent of developing an on-going sampling program at a smaller number of stations, with the selection of the stations to be based largely upon the results of this preliminary sampling program. When stations within a given stream showed similar results, fewer stations would be sampled in the future. Similarly, if a stream appeared to be perturbed, additional stations or chemical analyses might be added so that the source of the perturbation could be identified. In general, unperturbed streams will contain more taxa than perturbed streams, and the distribution of taxa among orders or families will differ. Some groups of macroinvertebrates, such as Ephemeroptera (mayflies), Plecoptera (stoneflies) and Trichoptera (caddisflies), which are collectively called EPT taxa, are considered to be relatively sensitive to most kinds of stream perturbation; therefore a reduced number of EPT taxa generally indicates that the stream has been subject to chemical or physical stressors. In coastal plain streams, EPT taxa are generally less dominant than in streams with rocky substrates, while Chironomidae (midges) are more abundant. (Abstract Truncated)

  18. Mercury exposure in a high fish eating Bolivian Amazonian population with intense small-scale gold-mining activities.

    Science.gov (United States)

    Barbieri, Flavia Laura; Cournil, Amandine; Gardon, Jacques

    2009-08-01

    Methylmercury exposure in Amazonian communities through fish consumption has been widely documented in Brazil. There is still a lack of data in other Amazonian countries, which is why we conducted this study in the Bolivian Amazon basin. Simple random sampling was used from a small village located in the lower Beni River, where there is intense gold mining and high fish consumption. All participants were interviewed and hair samples were taken to measure total mercury concentrations. The hair mercury geometric mean in the general population was 3.02 microg/g (CI: 2.69-3.37; range: 0.42-15.65). Age and gender were not directly associated with mercury levels. Fish consumption showed a positive relation and so did occupation, especially small-scale gold mining. Hair mercury levels were lower than those found in Brazilian studies, but still higher than in non-exposed populations. It is necessary to assess mercury exposure in the Amazonian regions where data is still lacking, using a standardized indicator.

  19. 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.

  20. Intertidal benthic community ecology of sand-dwelling macroinvertebrates of Goa beaches

    Digital Repository Service at National Institute of Oceanography (India)

    Harkantra, S.N.; Parulekar, A.H.

    Studies on the intertidal ecology of two sandy beaches of Goa along the western coast of India revealed the presence of 47 species of macroinvertebrates belonging to 32 families. The open beach at Candolim, characterized by coarse sand-grain size...

  1. Rare and common macroinvertebrates: definition of distribution classes and their boundaries

    NARCIS (Netherlands)

    Nijboer, R.C.; Verdonschot, P.F.M.

    2004-01-01

    Rarity of macroinvertebrates can be used in assessing the ecological quality or conservation value of freshwaters. To select target species for nature conservation and to compare rarity or commonness between regions a classification of species distributions is needed. A distribution classification

  2. Using Historical Atlas Data to Develop High-Resolution Distribution Models of Freshwater Fishes.

    Directory of Open Access Journals (Sweden)

    Jian Huang

    Full Text Available Understanding the spatial pattern of species distributions is fundamental in biogeography, and conservation and resource management applications. Most species distribution models (SDMs require or prefer species presence and absence data for adequate estimation of model parameters. However, observations with unreliable or unreported species absences dominate and limit the implementation of SDMs. Presence-only models generally yield less accurate predictions of species distribution, and make it difficult to incorporate spatial autocorrelation. The availability of large amounts of historical presence records for freshwater fishes of the United States provides an opportunity for deriving reliable absences from data reported as presence-only, when sampling was predominantly community-based. In this study, we used boosted regression trees (BRT, logistic regression, and MaxEnt models to assess the performance of a historical metacommunity database with inferred absences, for modeling fish distributions, investigating the effect of model choice and data properties thereby. With models of the distribution of 76 native, non-game fish species of varied traits and rarity attributes in four river basins across the United States, we show that model accuracy depends on data quality (e.g., sample size, location precision, species' rarity, statistical modeling technique, and consideration of spatial autocorrelation. The cross-validation area under the receiver-operating-characteristic curve (AUC tended to be high in the spatial presence-absence models at the highest level of resolution for species with large geographic ranges and small local populations. Prevalence affected training but not validation AUC. The key habitat predictors identified and the fish-habitat relationships evaluated through partial dependence plots corroborated most previous studies. The community-based SDM framework broadens our capability to model species distributions by innovatively

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

    Directory of Open Access Journals (Sweden)

    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

  4. 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.

  5. Diversity and abundance of aquatic macroinvertebrates in a lotic environment in Midwestern São Paulo State, Brazil

    Directory of Open Access Journals (Sweden)

    Gabriel Lucas Bochini

    2009-04-01

    Full Text Available This study analyzed the diversity and abundance of an aquatic macroinvertebrate community in the Vargem Limpa stream located in Bauru, Midwestern São Paulo State, and characterized the water quality based on biological parameters. The sampling was carried out during the rain season (December, 2004. It was analyzed and identified 3,068 organisms belonging to 9 macroinvertebrate families. The system showed low richness and diversity of organisms in response to water quality.

  6. Disentangling the effects of low pH and metal mixture toxicity on macroinvertebrate diversity

    Science.gov (United States)

    Fornaroli, Riccardo; Ippolito, Alessio; Tolkkinen, Mari J.; Mykrä, Heikki; Muotka, Timo; Balistrieri, Laurie S.; Schmidt, Travis S.

    2018-01-01

    One of the primary goals of biological assessment of streams is to identify which of a suite of chemical stressors is limiting their ecological potential. Elevated metal concentrations in streams are often associated with low pH, yet the effects of these two potentially limiting factors of freshwater biodiversity are rarely considered to interact beyond the effects of pH on metal speciation. Using a dataset from two continents, a biogeochemical model of the toxicity of metal mixtures (Al, Cd, Cu, Pb, Zn) and quantile regression, we addressed the relative importance of both pH and metals as limiting factors for macroinvertebrate communities. Current environmental quality standards for metals proved to be protective of stream macroinvertebrate communities and were used as a starting point to assess metal mixture toxicity. A model of metal mixture toxicity accounting for metal interactions was a better predictor of macroinvertebrate responses than a model considering individual metal toxicity. We showed that the direct limiting effect of pH on richness was of the same magnitude as that of chronic metal toxicity, independent of its influence on the availability and toxicity of metals. By accounting for the direct effect of pH on macroinvertebrate communities, we were able to determine that acidic streams supported less diverse communities than neutral streams even when metals were below no-effect thresholds. Through a multivariate quantile model, we untangled the limiting effect of both pH and metals and predicted the maximum diversity that could be expected at other sites as a function of these variables. This model can be used to identify which of the two stressors is more limiting to the ecological potential of running waters.

  7. 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...

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

    NARCIS (Netherlands)

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

    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

  9. 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

  10. Changes of Benthic Macroinvertebrates in Thi Vai River and Cai Mep Estuaries Under Polluted Conditions with Industrial Wastewater

    Directory of Open Access Journals (Sweden)

    Huong Nguyen Thi Thanh

    2017-06-01

    Full Text Available The pollution on the Thi Vai River has been spreading out rapidly over the two lasted decades caused by the wastewater from the industrial parks in the left bank of Thi Vai River and Cai Mep Estuaries. The evaluation of the benthic macroinvertebrate changes was very necessary to identify the consequences of the industrial wastewater on water quality and aquatic ecosystem of Thi Vai River and Cai Mep Estuaries. In this study, the variables of benthic macroinvertebrates and water quality were investigated in Thi Vai River and Cai Mep Estuaries, Southern Vietnam. The monitoring data of benthic macroinvertebrates and water quality parameters covered the period from 1989 to 2015 at 6 sampling sites in Thi Vai River and Cai Mep Estuaries. The basic water quality parameters were also tested including pH, dissolved oxygen (DO, total nitrogen, and total phosphorus. The biodiversity indices of benthic macroinvertebrates were applied for water quality assessment. The results showed that pH ranged from 6.4 – 7.6 during the monitoring. The DO concentrations were in between 0.20 - 6.70 mg/L. The concentrations of total nitrogen and total phosphorous ranged from 0.03 - 5.70 mg/L 0.024 - 1.380 mg/L respectively. Macroinvertebrate community in the study area consisted of 36 species of polychaeta, gastropoda, bivalvia, and crustacea, of which, species of polychaeta were dominant in species number. The benthic macroinvertebartes density ranged from 0 - 2.746 individuals/m−1 with the main dominant species of Neanthes caudata, Prionospio malmgreni, Paraprionospio pinnata, Trichochaeta carica, Maldane sarsi, Capitella capitata, Terebellides stroemi, Euditylia polymorpha, Grandidierella lignorum, Apseudes vietnamensis. The biodiversity index values during the monitoring characterized for aquatic environmental conditions of mesotrophic to polytrophic. Besides, species richness positively correlated with DO, total nitrogen, and total phosphorus. The results

  11. How are macroinvertebrates of slow flowing lotic systems directly affected by suspended and deposited sediments?

    Energy Technology Data Exchange (ETDEWEB)

    Kefford, Ben J., E-mail: ben.kefford@rmit.edu.a [Biotechnology and Environmental Biology, School of Applied Sciences, RMIT University, PO Box 71, Bundoora, Victoria 3083 (Australia); Zalizniak, Liliana [Biotechnology and Environmental Biology, School of Applied Sciences, RMIT University, PO Box 71, Bundoora, Victoria 3083 (Australia); Dunlop, Jason E. [Department of Environment and Resource Management (DERM), 120 Meiers Rd, Indooroopilly, Queensland 4068 (Australia); Smart Water Research Facility, Griffith University, Queensland (Australia); Nugegoda, Dayanthi [Biotechnology and Environmental Biology, School of Applied Sciences, RMIT University, PO Box 71, Bundoora, Victoria 3083 (Australia); Choy, Satish C. [Department of Environment and Resource Management (DERM), 120 Meiers Rd, Indooroopilly, Queensland 4068 (Australia)

    2010-02-15

    The effects of suspended and deposited sediments on the macroinvertebrates are well documented in upland streams but not in slower flowing lowland rivers. Using species found in lowland lotic environments, we experimentally evaluate mechanisms for sediments to affect macroinvertebrates, and in one experiment whether salinity alters the effect of suspended sediments. Suspended kaolin clay reduced feeding of Ischnura heterosticta (Odonata: Coenagrionidae) at high turbidity (1000-1500 NTU) but had no effects on feeding of Hemianax papuensis (Odonata: Aeshnidae) and Micronecta australiensis (Hemiptera: Corixidae). In freshwater (0.1 mS/cm), survival of Ischnura aurora was poor in clear water, but improved with suspended kaolin. Growth and feeding of I. aurora were unaffected by suspended sediments and salinity. Burial (1-5 mm) of eggs with kaolin or sand reduced hatching in Physa acuta (Gastropoda: Physidae), Gyraulus tasmanica (Gastropoda: Planorbidae) and Chironomus cloacalis (Diptera: Chironomidae). Settling sediments may pose greater risk to lowland lotic invertebrates than suspended sediments. - Sediment deposition may be more directly detrimental to macroinvertebrates of lowland rivers than suspended sediments.

  12. Ecological impact assessment of sediment remediation in a metal-contaminated lowland river using translocated zebra mussels and resident macroinvertebrates

    International Nuclear Information System (INIS)

    De Jonge, M.; Belpaire, C.; Geeraerts, C.; De Cooman, W.; Blust, R.; Bervoets, L.

    2012-01-01

    The present study investigated to what extent accumulated metal levels in aquatic invertebrates can reflect environmental contamination and how these tissue levels can be related to alterations in macroinvertebrate communities in the dredged River Dommel. Metal accumulation was measured in translocated zebra mussels (Dreissena polymorpha) and resident Chironomidae. Furthermore, macroinvertebrate community composition was assessed. Our results indicated that trends of total metal concentrations in surface water of the Dommel in time are reflected well by metal levels in tissue of D. polymorpha. In contrast, sediment-bound metals were the most dominant exposure route for Chironomidae. Alterations in macroinvertebrate community composition were observed during dredging and significant relations between metal levels in invertebrate tissues and ecological responses were found. Our results demonstrated that metal accumulation in both zebra mussels and Chironomidae can be used as an integrated measure of metal bioavailability and to predict ecological effects of metal toxicity on macroinvertebrate communities. - Highlights: ► The use of tissue concentrations to assess environmental metal pollution was studied. ► Metal accumulation was measured in caged zebra mussels and resident Chironomidae. ► Shell condition of mussels and macroinvertebrate taxa distribution was assessed. ► Different accumulation between biota and relations with community level were found. ► Bioaccumulation is an integrated measure of metal toxicity in aquatic communities. - Metal accumulation in selected aquatic invertebrates can be used as an integrated measure of metal bioavailability and to predict ecological effects of metal toxicity.

  13. Compliance of secondary production and eco-exergy as indicators of benthic macroinvertebrates assemblages' response to canopy cover conditions in Neotropical headwater streams.

    Science.gov (United States)

    Linares, Marden Seabra; Callisto, Marcos; Marques, João Carlos

    2018-02-01

    Riparian vegetation cover influences benthic assemblages structure and functioning in headwater streams, as it regulates light availability and autochthonous primary production in these ecosystems.Secondary production, diversity, and exergy-based indicators were applied in capturing how riparian cover influences the structure and functioning of benthic macroinvertebrate assemblages in tropical headwater streams. Four hypotheses were tested: (1) open canopy will determine the occurrence of higher diversity in benthic macroinvertebrate assemblages; (2) streams with open canopy will exhibit more complex benthic macroinvertebrate communities (in terms of information embedded in the organisms' biomass); (3) in streams with open canopy benthic macroinvertebrate assemblages will be more efficient in using the available resources to build structure, which will be reflected by higher eco-exergy values; (4) benthic assemblages in streams with open canopy will exhibit more secondary productivity. We selected eight non-impacted headwater streams, four shaded and four with open canopy, all located in the Neotropical savannah (Cerrado) of southeastern Brazil. Open canopy streams consistently exhibited significantly higher eco-exergy and instant secondary production values, exemplifying that these streams may support more complex and productive benthic macroinvertebrate assemblages. Nevertheless, diversity indices and specific eco-exergy were not significantly different in shaded and open canopy streams. Since all the studied streams were selected for being considered as non-impacted, this suggests that the potential represented by more available food resources was not used to build a more complex dissipative structure. These results illustrate the role and importance of the canopy cover characteristics on the structure and functioning of benthic macroinvertebrate assemblages in tropical headwater streams, while autochthonous production appears to play a crucial role as food

  14. Collision recognition and direction changes for small scale fish robots by acceleration sensors

    Science.gov (United States)

    Na, Seung Y.; Shin, Daejung; Kim, Jin Y.; Lee, Bae-Ho

    2005-05-01

    Typical obstacles are walls, rocks, water plants and other nearby robots for a group of small scale fish robots and submersibles that have been constructed in our lab. Sonar sensors are not employed to make the robot structure simple enough. All of circuits, sensors and processor cards are contained in a box of 9 x 7 x 4 cm dimension except motors, fins and external covers. Therefore, image processing results are applied to avoid collisions. However, it is useful only when the obstacles are located far enough to give images processing time for detecting them. Otherwise, acceleration sensors are used to detect collision immediately after it happens. Two of 2-axes acceleration sensors are employed to measure the three components of collision angles, collision magnitudes, and the angles of robot propulsion. These data are integrated to calculate the amount of propulsion direction change. The angle of a collision incident upon an obstacle is the fundamental value to obtain a direction change needed to design a following path. But there is a significant amount of noise due to a caudal fin motor. Because caudal fin provides the main propulsion for a fish robot, there is a periodic swinging noise at the head of a robot. This noise provides a random acceleration effect on the measured acceleration data at the collision. We propose an algorithm which shows that the MEMS-type accelerometers are very effective to provide information for direction changes in spite of the intrinsic noise after the small scale fish robots have made obstacle collision.

  15. Analysis of habitat characteristics of small pelagic fish based on generalized additive models in Kepulauan Seribu Waters

    Science.gov (United States)

    Rivai, A. A.; Siregar, V. P.; Agus, S. B.; Yasuma, H.

    2018-03-01

    One of the required information for sustainable fisheries management is about the habitat characteristics of a fish species. This information can be used to map the distribution of fish and map the potential fishing ground. This study aimed to analyze the habitat characteristics of small pelagic fishes (anchovy, squid, sardine and scads) which were mainly caught by lift net in Kepulauan Seribu waters. Research on habitat characteristics had been widely done, but the use of total suspended solid (TSS) parameters in this analysis is still lacking. TSS parameter which was extracted from Landsat 8 along with five other oceanographic parameters, CPUE data and location of fishing ground data from lift net fisheries in Kepulauan Seribu were included in this analysis. This analysis used Generalized Additive Models (GAMs) to evaluate the relationship between CPUE and oceanographic parameters. The results of the analysis showed that each fish species had different habitat characteristics. TSS and sea surface height had a great influence on the value of CPUE from each species. All the oceanographic parameters affected the CPUE of each species. This study demonstrated the effective use of GAMs to identify the essential habitat of a fish species.

  16. Tritium uptake by fish in a small stream

    International Nuclear Information System (INIS)

    Eaton, D.; Murphy, C.E. Jr.

    1992-01-01

    The tritium concentration in the water from freeze drying and the water from combustion of the dry tissue was measured in fish (largemouth bass), stream macrophytes, and streamside vegetation at five sampling locations in Four Mile Branch on the Savannah River Site (SRS). Four Mile Branch has elevated tritium concentration, largely from migration of water through the soil from adjacent seepage basins that received industrial wastewater containing tritium. The stream water and the vegetation, through the food chain, are thought to be the two sources of tritium reaching the fish. Comparision of the tritium activity of the freeze-dried water from fish flesh and of the sources of tritium, indicates that the fish flesh approaches a steady-state concentration with the stream water. The freeze-dry water from the vegetation is also at a lower specific activity than the stream water. The water of combustion from the vegetation is also at a lower specific activity than stream water. The water of combustion from the fish flesh is somewhat higher in specific activity than the stream water or the water in the fish. The distribution of tritium among the components of this system can be explain in terms of the turnover of water and organic hydrogen in the components

  17. Design optimization of a vaneless ``fish-friendly'' swirl injector for small water turbines

    Science.gov (United States)

    Airody, Ajith; Peterson, Sean D.

    2015-11-01

    Small-scale hydro-electric plants are attractive options for powering remote sites, as they draw energy from local bodies of water. However, the environmental impact on the aquatic life drawn into the water turbine is a concern. To mitigate adverse consequences on the local fauna, small-scale water turbine design efforts have focused on developing ``fish-friendly'' facilities. The components of these turbines tend to have wider passages between the blades when compared to traditional turbines, and the rotors are designed to spin at much lower angular velocities, thus allowing fish to pass through safely. Galt Green Energy has proposed a vaneless casing that provides the swirl component to the flow approaching the rotor, eliminating the need for inlet guide vanes. We numerically model the flow through the casing using ANSYS CFX to assess the evolution of the axial and circumferential velocity symmetry and uniformity in various cross-sections within and downstream of the injector. The velocity distributions, as well as the pressure loss through the injector, are functions of the pitch angle and number of revolutions of the casing. Optimization of the casing design is discussed via an objective function consisting of the velocity and pressure performance measures.

  18. Downstream passage of fish larvae and eggs through a small-sized reservoir, Mucuri river, Brazil

    Directory of Open Access Journals (Sweden)

    Paulo S. Pompeu

    2011-12-01

    Full Text Available In South America, one important symptom of the failure of fish passages to sustain fish migratory recruitment is the inability of eggs and larvae to reach the nurseries. This is especially so when the breeding areas are located upstream of a reservoir, and the floodplain is downstream of the dam. Therefore, the transport of fish larvae and eggs across reservoir barriers is a key factor in the development of effective conservation strategies. In this paper, we evaluate the potential for migratory fish larvae and egg transportation across a small size reservoir in eastern Brazil. We sampled fish daily between 15th October 2002 and 15th February 2003 (spawning period in the Mucuri River, immediately upstream of the reservoir and downstream of the Santa Clara Power Plant dam. Our study was the first to indicate the possibility of successful larval passage through the reservoir of a hydroelectric reservoir and dam in South America, and showed that the passage of migratory fish larvae was associated significantly with residence time of water in the reservoir. The relatively short water residence time and elevated turbidity of the Santa Clara's reservoir waters during the rainy season certainly contributed to the successful passage, and can be considered as key factors for a priori evaluations of the feasibility of a downstream larval passage.

  19. Are vegetated areas of mangroves attractive to juvenile and small fish? The case of Dongzhaigang Bay, Hainan Island, China

    Science.gov (United States)

    Wang, Mao; Huang, Zhenyuan; Shi, Fushan; Wang, Wenqing

    2009-11-01

    Well-developed aerial roots of mangroves make it difficult to study how fish utilize the mangrove forest as a habitat. In the present study, we compared the differences in fish assemblages in three major types of habitats of mangrove estuary (vegetated area, treeless mudflat, and creek) of a mangrove bay in Hainan Island, China, at different seasons during two consecutive years. Three types of gears, centipede net, gill net and cast net, were used in the different habitats of mangrove estuary and sampling efficiencies among gears were evaluated. Centipede nets were used in all the three types of habitats and cast nets and gill nets in treeless mudflats and creeks. Fish assemblages were dependent on gears used. Centipede net could efficiently catch fish occurring both inside and outside of vegetated areas efficiently. A total of 115 fish species in 51 families were collected. In terms of numbers of species per family, Gobiidae was the most diverse (17 species), followed by Mugilidae (5 species). Almost all of the fish were juvenile or small fish and few predators were recorded, implying low predation pressure in the bay. ANOVA analysis showed that significant seasonal and spatial variation existed in species richness, abundance, and biomass, which were less in the vegetated areas than those of treeless mudflats and creeks. The attraction of vegetated areas to fish was less than that of creeks and mudflats. Many species were specific to a particular habitat type, 4 species occurring exclusively in the creeks, 45 species occurring exclusively in the treeless mudflats, and 5 species occurring exclusively in the vegetated areas. The results indicated that mangrove estuaries were potentially attractive habitats for juvenile and small fish, but this attraction was accomplished by a connection of vegetated areas, treeless mudflats and creeks, not only by vegetated areas.

  20. Spatio-temporal patterns and environmental controls of small pelagic fish body condition from contrasted Mediterranean areas

    Science.gov (United States)

    Brosset, Pablo; Fromentin, Jean-Marc; Van Beveren, Elisabeth; Lloret, Josep; Marques, Virginie; Basilone, Gualtiero; Bonanno, Angelo; Carpi, Piera; Donato, Fortunata; Čikeš Keč, Vanja; De Felice, Andrea; Ferreri, Rosalia; Gašparević, Denis; Giráldez, Ana; Gücü, Ali; Iglesias, Magdalena; Leonori, Iole; Palomera, Isabel; Somarakis, Stylianos; Tičina, Vjekoslav; Torres, Pedro; Ventero, Ana; Zorica, Barbara; Ménard, Frédéric; Saraux, Claire

    2017-02-01

    Small pelagic fish are among the most ecologically and economically important marine fish species and are characterized by large fluctuations all over the world. In the Mediterranean Sea, low catches and biomass of anchovies and sardines have been described in some areas during the last decade, resulting in important fisheries crises. Therefore, we studied anchovy and sardine body condition variability, a key index of population health and its response to environmental and anthropogenic changes. Wide temporal and spatial patterns were investigated by analyzing separately data from scientific surveys and fisheries in eight Mediterranean areas between 1975 and 2015. Results showed that anchovy and sardine body condition as well as maximum size in some areas sharply decreased in most Mediterranean areas along years (except in the Northern Alboran Sea). Despite this general pattern, well-marked environmental differences between sub-regions were highlighted by several analyses and variations in body condition were not found to be homogeneous over all the Mediterranean Sea. Further, other analyses revealed that except for the Adriatic where major changes towards a lower body condition were concomitant with a decrease in river runoffs and chl-a concentration, no concomitant environmental regime shift was detected in other areas. Together, these analyses highlighted the current poor body condition of almost all small pelagic fish populations in the Mediterranean. Yet, global environmental indices could not explain the observed changes and the general decrease in condition might more likely come from regional environmental and/or anthropogenic (fishing) effects. A prolonged state of poor fish body condition, together with an observed reduced size and early age-at-maturity may have strong ecological, economic and social consequences all around the Mediterranean Sea.

  1. 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 - others: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

  2. Assessing combined impacts of agrochemicals: Aquatic macroinvertebrate population responses in outdoor mesocosms.

    Science.gov (United States)

    Barmentlo, S Henrik; Schrama, Maarten; Hunting, Ellard R; Heutink, Roel; van Bodegom, Peter M; de Snoo, Geert R; Vijver, Martina G

    2018-08-01

    Agricultural ditches host a diverse community of species. These species often are unwarrantedly exposed to fertilizers and a wide-array of pesticides (hereafter: agrochemicals). Standardized ecotoxicological research provides valuable information to predict whether these pesticides possibly pose a threat to the organisms living within these ditches, in particular macro-invertebrates. However, knowledge on how mixtures of these agrochemicals affect macro-invertebrates under realistic abiotic conditions and with population and community complexity is mostly lacking. Therefore we examined here, using a full factorial design, the population responses of macroinvertebrate species assemblages exposed to environmentally relevant concentrations of three commonly used agrochemicals (for 35days) in an outdoor experiment. The agrochemicals selected were an insecticide (imidacloprid), herbicide (terbuthylazine) and nutrients (NPK), all having a widespread usage and often detected together in watersheds. Effects on species abundance and body length caused by binary mixture combinations could be described from single substance exposure. However, when agrochemicals were applied as tertiary mixtures, as they are commonly found in agricultural waters, species' abundance often deviated from expectations made based on the three single treatments. This indicates that pesticide-mixture induced toxicity to population relevant endpoints are difficult to extrapolate to field conditions. As in agricultural ditches often a multitude (approx. up to 7) of agrochemicals residues are detected, we call other scientist to verify the ecological complexity of non-additive induced shifts in natural aquatic invertebrate populations and aquatic species assemblages. Copyright © 2018 Elsevier B.V. All rights reserved.

  3. Investigating the influence of heavy metals on macro-invertebrate assemblages using Partial Cononical Correspondence Analysis (pCCA)

    Science.gov (United States)

    Beasley, Gary; Kneale, Pauline E.

    This paper defines the spectrum of impairment to stream macroinvertebrates arising from urban runoff. Field sampling of stream sediments at 62 sites across Yorkshire, UK was used to investigate the influence of heavy metals and habitat on macroinvertebrate family distribution using partial Canonical Correspondence Analysis (pCCA). Increasing urbanization and trafficking was associated with increasing levels of metal pollution but, even when traffic is light, family numbers can be reduced by 50%. Industrial areas and motorway runoff depress macroinvertebrate numbers but drainage from streets with no off-road parking in residential areas can have similar impacts. The heavy metals in the sediment accounted for approximately 24% of the variation in macroinvertebrate community composition while the physical habitat variables used in RIVPACS (River InVertebrate Prediction And Classification System) (Wright, 2000) accounted for an additional 30%. Zinc and nickel were the main metal influences regardless of the time of sampling; at these sites copper is less than critical. Results agree with those reported in other studies in which families mainly from the orders Ephemeroptera (mayfly), Plecoptera (stonefly) and Tricoptera (caddisfly) displayed metal sensitivity in that they were absent from metal polluted streams. However, within each of these orders, a continuum of sensitivity is evident: this highlights the risks of generalising on orders rather than using family or indeed species data.

  4. Macroinvertebrate response to acid mine drainage: community metrics and on-line behavioural toxicity bioassay

    Energy Technology Data Exchange (ETDEWEB)

    A. Gerhardt; L. Janssens de Bisthoven; A.M.V.M. Soares [University of Aveiro, Aveiro (Portugal). Department of Biology

    2004-07-01

    The hypothesis is tested that toxicity of acid mine drainage can be detected by a selection of existing macroinvertebrate community and bioindicator metrices supplemented by toxicity tests with the local mosquitofish Gambusia holbrooki Girard and the shrimp Atyaephyra desmaresti Millet. The behavioural responses of A. desmaresti to acid mine drainage were recorded in the Multispecies Freshwater Biomonitor{reg_sign}, based on behaviour and survival as parameters. Bioassessment methods were based on community diversity, structure, function, and bioindicators and supplemented by chemical analysis (temperature, pH, metals). The Biological Monitoring Working Party adapted for the Iberian Peninsula, the number of predators (Coleoptera, Hemiptera) and the number of Ephemeroptera and Trichoptera taxa differentiated the sites well. The on-line toxicity test revealed pH-dependent acute toxicity of the acid mine drainage for the shrimp (LC{sub 50}-48 h: pH-AMD=5.8) and a pH-dependent decrease in locomotory activity with the lowest-observed-response-times (LORTs) within 5 h of exposure. Shrimp were more sensitive to acid mine drainage than fish (LC{sub 50}-48 h: pH-AMD=4.9). A new multimetric index combining toxicity testing and bioassessment methods is proposed.

  5. Relationships between soil properties and community structure of soil macroinvertebrates in oak-history forests along an acidic deposition gradient

    Energy Technology Data Exchange (ETDEWEB)

    Kuperman, R.G. [Argonne National Lab., IL (United States). Environmental Assessment Div.

    1996-02-01

    Soil macroinvertebrate communities were studied in ecologically analogous oak-hickory forests across a three-state atmospheric pollution gradient in Illinois, Indiana, and Ohio. The goal was to investigate changes in the community structure of soil fauna in study sites receiving different amounts of acidic deposition for several decades and the possible relationships between these changes and physico-chemical properties of soil. The study revealed significant differences in the numbers of soil animals among the three study sites. The sharply differentiated pattern of soil macroinvertebrate fauna seems closely linked to soil chemistry. Significant correlations of the abundance of soil macroinvertebrates with soil parameters suggest that their populations could have been affected by acidic deposition in the region. Abundance of total soil macroinvertebrates decreased with the increased cumulative loading of acidic deposition. Among the groups most sensitive to deposition were: earthworms gastropods, dipteran larvae, termites, and predatory beetles. The results of the study support the hypothesis that chronic long-term acidic deposition could aversely affect the soil decomposer community which could cause lower organic matter turnover rates leading to an increase in soil organic matter content in high deposition sites.

  6. Biodiversity assessment of benthic macroinvertebrates along a reservoir cascade in the lower São Francisco river (northeastern Brazil

    Directory of Open Access Journals (Sweden)

    M. Callisto

    Full Text Available In order to verify the cascade-system effect in benthic macroinvertebrate communities, and the implications for policy making and proposals for conservation and sustainable use of the lower portion of São Francisco river basin (Bahia State, Brazil, a three-reservoir cascade system including two stretches downstream were studied during dry (June, 1997 and rainy (March, 1998 periods. The dominant groups found were Mollusca (Melanoides tuberculata, Oligochaeta, and Chironomidae larvae. Low Shannon-Wiener and Pielou index values were found, but with no significant difference between the sampling periods. However, density and taxonomic richness were significantly different (t(0.05; 31 = -2.1945; p < 0.05; e t(0.05; 31 = -3.0600; p < 0.01 between the sampling periods, with a reduction in the number of taxaand macroinvertebrate abundance during the rainy period. An increasing gradient in benthic macroinvertebrate community structures was noted along the reservoir cascade from the first reservoir (Apolônio Sales, followed by a decrease downstream from the third reservoir of the system (Xingó. Despite the negative consequences of rapid proliferation of dams, which have caused widespread loss of freshwater habitats, the reservoir cascade system promoted an increase in benthic macroinvertebrate diversity, due to water-quality improvement along the system.

  7. Disentangling the effects of low pH and metal mixture toxicity on macroinvertebrate diversity.

    Science.gov (United States)

    Fornaroli, Riccardo; Ippolito, Alessio; Tolkkinen, Mari J; Mykrä, Heikki; Muotka, Timo; Balistrieri, Laurie S; Schmidt, Travis S

    2018-04-01

    One of the primary goals of biological assessment of streams is to identify which of a suite of chemical stressors is limiting their ecological potential. Elevated metal concentrations in streams are often associated with low pH, yet the effects of these two potentially limiting factors of freshwater biodiversity are rarely considered to interact beyond the effects of pH on metal speciation. Using a dataset from two continents, a biogeochemical model of the toxicity of metal mixtures (Al, Cd, Cu, Pb, Zn) and quantile regression, we addressed the relative importance of both pH and metals as limiting factors for macroinvertebrate communities. Current environmental quality standards for metals proved to be protective of stream macroinvertebrate communities and were used as a starting point to assess metal mixture toxicity. A model of metal mixture toxicity accounting for metal interactions was a better predictor of macroinvertebrate responses than a model considering individual metal toxicity. We showed that the direct limiting effect of pH on richness was of the same magnitude as that of chronic metal toxicity, independent of its influence on the availability and toxicity of metals. By accounting for the direct effect of pH on macroinvertebrate communities, we were able to determine that acidic streams supported less diverse communities than neutral streams even when metals were below no-effect thresholds. Through a multivariate quantile model, we untangled the limiting effect of both pH and metals and predicted the maximum diversity that could be expected at other sites as a function of these variables. This model can be used to identify which of the two stressors is more limiting to the ecological potential of running waters. Copyright © 2018 Elsevier Ltd. All rights reserved.

  8. Relative and combined effects of habitat and fishing on reef fish communities across a limited fishing gradient at Ningaloo.

    Science.gov (United States)

    Wilson, Shaun K; Babcock, Russ C; Fisher, Rebecca; Holmes, Thomas H; Moore, James A Y; Thomson, Damian P

    2012-10-01

    Habitat degradation and fishing are major drivers of temporal and spatial changes in fish communities. The independent effects of these drivers are well documented, but the relative importance and interaction between fishing and habitat shifts is poorly understood, particularly in complex systems such as coral reefs. To assess the combined and relative effects of fishing and habitat we examined the composition of fish communities on patch reefs across a gradient of high to low structural complexity in fished and unfished areas of the Ningaloo Marine Park, Western Australia. Biomass and species richness of fish were positively correlated with structural complexity of reefs and negatively related to macroalgal cover. Total abundance of fish was also positively related to structural complexity, however this relationship was stronger on fished reefs than those where fishing is prohibited. The interaction between habitat condition and fishing pressure is primarily due to the high abundance of small bodied planktivorous fish on fished reefs. However, the influence of management zones on the abundance and biomass of predators and target species is small, implying spatial differences in fishing pressure are low and unlikely to be driving this interaction. Our results emphasise the importance of habitat in structuring reef fish communities on coral reefs especially when gradients in fishing pressure are low. The influence of fishing effort on this relationship may however become more important as fishing pressure increases. Copyright © 2012 Elsevier Ltd. All rights reserved.

  9. From "Duck Factory" to "Fish Factory": Climate induced changes in vertebrate communities of prairie pothole wetlands and small lakes

    Science.gov (United States)

    McLean, Kyle I.; Mushet, David M.; Stockwell, Craig A.

    2016-01-01

    The Prairie Pothole Region’s myriad wetlands and small lakes contribute to its stature as the “duck factory” of North America. The fishless nature of the region’s aquatic habitats, a result of frequent drying, freezing, and high salinity, influences its importance to waterfowl. Recent precipitation increases have resulted in higher water levels and wetland/lake freshening. In 2012–13, we sampled chemical characteristics and vertebrates (fish and salamanders) of 162 Prairie Pothole wetlands and small lakes. We used non-metric multidimensional scaling, principal component analysis, and bootstrapping techniques to reveal relationships. We found fish present in a majority of sites (84 %). Fish responses to water chemistry varied by species. Fathead minnows (Pimephales promelas) and brook sticklebacks (Culaea inconstans) occurred across the broadest range of conditions. Yellow perch (Perca flavescens) occurred in a smaller, chemically defined, subset. Iowa darters (Etheostoma exile) were restricted to the narrowest range of conditions. Tiger salamanders (Ambystoma mavortium) rarely occurred in lakes with fish. We also compared our chemical data to similar data collected in 1966–1976 to explore factors contributing to the expansion of fish into previously fishless sites. Our work contributes to a better understanding of relationships between aquatic biota and climate-induced changes in this ecologically important area.

  10. Artificial barriers prevent genetic recovery of small isolated populations of a low-mobility freshwater fish.

    Science.gov (United States)

    Coleman, R A; Gauffre, B; Pavlova, A; Beheregaray, L B; Kearns, J; Lyon, J; Sasaki, M; Leblois, R; Sgro, C; Sunnucks, P

    2018-01-12

    Habitat loss and fragmentation often result in small, isolated populations vulnerable to environmental disturbance and loss of genetic diversity. Low genetic diversity can increase extinction risk of small populations by elevating inbreeding and inbreeding depression, and reducing adaptive potential. Due to their linear nature and extensive use by humans, freshwater ecosystems are especially vulnerable to habitat loss and fragmentation. Although the effects of fragmentation on genetic structure have been extensively studied in migratory fishes, they are less understood in low-mobility species. We estimated impacts of instream barriers on genetic structure and diversity of the low-mobility river blackfish (Gadopsis marmoratus) within five streams separated by weirs or dams constructed 45-120 years ago. We found evidence of small-scale (barriers, as expected for a fish with low mobility. Genetic diversity was lower above barriers in small streams only, regardless of barrier age. In particular, one isolated population showed evidence of a recent bottleneck and inbreeding. Differentiation above and below the barrier (F ST  = 0.13) was greatest in this stream, but in other streams did not differ from background levels. Spatially explicit simulations suggest that short-term barrier effects would not be detected with our data set unless effective population sizes were very small (barriers is reduced and requires more genetic markers compared to panmictic populations. We also demonstrate the importance of accounting for natural population genetic structure in fragmentation studies.

  11. Importance of small fishes and invasive crayfish in otter Lutra lutra diet in an English chalk stream

    OpenAIRE

    Britton, J.R.; Berry, M.; Sewell, S.; Lees, C.; Reading, P.

    2017-01-01

    The diet composition of the European otter Lutra lutra was assessed using spraint analysis in the Hampshire Avon, a lowland chalk stream in Southern England, over an 18-month period. Small cyprinid fishes were the main prey item taken in all seasons, with bullhead Cottus gobio and stone loach Barbatula barbatula also important; there were relatively few larger fishes of interest to fisheries found. There were significant seasonal differences in diet composition by season, with signal crayfish...

  12. Influence of agricultural land-use and pesticides on benthic macroinvertebrate assemblages in an agricultural river basin in southeast Brazil

    Directory of Open Access Journals (Sweden)

    M Egler

    Full Text Available Land-use alterations and pesticide run-offs are among the main causes for impairment in agricultural areas. We evaluated the influence of different land-uses (forest, pasture and intensive agriculture on the water quality and on benthic macroinvertebrate assemblages on three occasions: in the dry season, wet season and at the end of the wet season. Macroinvertebrates responded to this gradient of impairment: agricultural sites had significantly lower richness numbers than forested and pasture sites, and all major invertebrate groups were significantly affected. Most taxa found in forested sites were found in pasture sites, but often with lower densities. In this case, the loss of habitats due to sedimentation and the lower complexity of substrates seem to be the disruptive force for the macroinvertebrate fauna.

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

    Energy Technology Data Exchange (ETDEWEB)

    Maltby, Lorraine [Department of Animal and Plant Sciences, University of Sheffield, Western Bank, Sheffield S10 2TN (United Kingdom)], E-mail: l.maltby@sheffield.ac.uk; Hills, Louise [Department of Animal and Plant Sciences, University of Sheffield, Western Bank, Sheffield S10 2TN (United Kingdom)

    2008-12-15

    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.

  14. Mesohabitat mosaic in lowland braided rivers: Short-term variability of macroinvertebrate metacommunities

    Directory of Open Access Journals (Sweden)

    Gemma Burgazzi

    2017-04-01

    Full Text Available Braided rivers are among the most variable and dynamic riverine systems. Changes in these environments are sudden and frequent, driven by the high hydrological variability. They host high levels of local heterogeneity, with many different habitats in close proximity establishing a mosaic of patches. This provides the conditions for high levels of biodiversity, with strong community variability in particular among the different habitats at the stream-reach level. Nevertheless, these systems are still poorly studied and their complexity is often not taken into account in biomonitoring protocols. We applied mixed effects modelling, spatial ordination techniques and beta-diversity partitioning (into nestedness and turnover components with the aim of improving the knowledge of braided rivers, investigating: i the organization of macroinvertebrate communities among the different habitats of a river reach, and ii the temporal variability of this organization (both among seasons and during summer. We predicted a differentiation of macroinvertebrate communities between distinct habitats within rivers, with this differentiation increasing during the low-flow period. We carried out our study in four braided rivers and streams of the Po River basin (Northern Italy sampling three different kinds of mesohabitats (main channel, secondary channel and pool in eight stations during seven campaigns from June 2015 to April 2016. We found a high variability of taxa richness, abundance and community structure among mesohabitats, with marginal ones accounting for the greater part of macroinvertebrate diversity. Secondary channels resulted as being the habitat hosting greater taxa diversity, with 10 exclusive taxa. Surprisingly the mesohabitat communities differed greatly during the seasonal phase, whereas their dissimilarity decreased during summer. This could be explained considering the summer flow reduction as a homogenizing force, leading to a general loss of the

  15. Surface-water hydrology and quality, and macroinvertebrate and smallmouth bass populations in four stream basins in southwestern Wisconsin, 1987-90

    Science.gov (United States)

    Graczyk, David J.; Lillie, Richard A.; Schlesser, Roger A.; Mason, John W.; Lyons, John D.; Kerr, Roger A.; Graczyk, David J.

    1993-01-01

    Data on streamflow, water quality, and macroinvertebrate and smallmouth bass (microptercus dolomieni) populations were collected from July 1987 through September 1990, in four streams in southwestern Wisconsin to determine the effect of surface-water hydrology and quality on populations of macroinvertebrates and smallmouth bass. The study was a joint project of the U.S. Geological Survey and the Wisconsin Department of Natural Resources.

  16. Analysis of Environmental Issues Related to Small-Scale Hydroelectric Development II: Design Consideration for Passing Fish Upstream Around Dams

    Energy Technology Data Exchange (ETDEWEB)

    Hildebrandt, S. G. [Oak Ridge National Lab. (ORNL), Oak Ridge, TN (United States); Bell, M. C. [Oak Ridge National Lab. (ORNL), Oak Ridge, TN (United States); Anderson, J. J. [Oak Ridge National Lab. (ORNL), Oak Ridge, TN (United States); Richey, E. P. [Oak Ridge National Lab. (ORNL), Oak Ridge, TN (United States); Parkhurst, Z. E. [Oak Ridge National Lab. (ORNL), Oak Ridge, TN (United States)

    1980-08-01

    The purpose of this report is to provide general information for use by potential developers of small scale hydroelectric projects that will include facilities to pass migrating fish upstream around dams. The document is not intended to be a textbook on design of fish passage facilities, but rather to be a general guide to some factors that are important when designing such facilities.

  17. Short-term disturbance effects of outdoor education stream classes on aquatic macroinvertebrates

    Science.gov (United States)

    Outdoor education stream classes provide students with an opportunity to gain hands-on experience with sampling methods for evaluating stream water quality. Student trampling as a result of stream classes may disrupt the substrate and negatively impact aquatic macroinvertebrates. The impact of stude...

  18. Fish Community Structure and Diet Responses to Newbury Weirs in a Low-Gradient River

    Science.gov (United States)

    Bonjour, Sophia M.; Rantala, Heidi M.; Bennett, Micah G.; Whiles, Matt R.

    2018-06-01

    Restoration projects are often implemented to address specific issues in the environment. Consequences of a restoration project, if any are measured, typically focus on direct changes to the projects focus. However, changing habitat structure likely results in changes to the environment that affect the communities living there. Rock weirs have been used for channel stabilization in many midwestern rivers. Previous research in a southern Illinois river found that weirs benefitted aquatic macroinvertebrate and riparian bird communities by enhancing habitat heterogeneity and insect emergence production. We hypothesized that fishes would also benefit from weirs through enhanced habitat and food availability. We collected fishes in the Cache River in southern Illinois using hand nets, seines, and electroshocking at sites where weirs had been installed and at non-weir sites. Gut contents were identified and individual food items measured. Fish species richness, but not diversity, was higher at weir sites. Fish communities also differed between site types, with benthic feeders characterizing weir sites. Gut content biomass and abundance differed among fish guilds but not between weir and non-weir sites. Fishes from both site types selected for prey taxa predominately found at weirs. Differences between site types were not always captured by univariate metrics, but connecting fish prey to habitat suggests a reach-scale benefit for fishes through increased abundance of favored prey and enhanced prey diversity. Additionally, given the paucity of rocky substrata in the river as a whole, rock weirs enhance fish species richness by providing habitat for less common benthic species.

  19. Soft sediment dwelling macro-invertebrates of Rajapur Bay, central west coast of India

    Digital Repository Service at National Institute of Oceanography (India)

    Harkantra, S.N.; Parulekar, A.H.

    Thirtyfour species of soft sediment dwelling macro-invertebrates were recorded in Rajapur Bay at the proposed effluent discharge location of nuclear power plant. The fauna mainly composed of polychaetes (42.52%), molluscs (39.03%), crustaceans (7...

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

    Science.gov (United States)

    Bryer, Pamela J; Scoggins, Mateo; McClintock, Nancy L

    2010-05-01

    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 pavement sealants contain bioavailable PAHs that may harm aquatic environments. Copyright 2009 Elsevier Ltd. All rights reserved.

  1. 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.

  2. Fish eye optics

    Science.gov (United States)

    Hudec, R.; Michalova, S.

    2017-07-01

    We report on small student (high—school) project of the Czech Academy of Sciences dealing with animal (fish) eyes and possible application in science and technology. Albeit most fishes have refractive eyes, the recent discoveries confirm that some fishes have reflective eyes with strange arrangements as well.

  3. 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.

  4. Selenium poisoning of fish by coal ash wastewater in Herrington Lake, Kentucky.

    Science.gov (United States)

    Lemly, A Dennis

    2018-04-15

    Selenium pollution from the E.W. Brown Electric Generating Station was investigated in Herrington Lake, KY. Coal ash wastewater is discharged as surface water overflow from ash disposal ponds into the lake via a National Pollutant Discharge Elimination System permit issued by the Kentucky Division of Water, but the permit does not restrict or limit the amount of selenium released. Unpermitted discharges occur from seeps and drainage through leaks in ash pond dams. Together, these discharges have resulted in selenium concentrations in water, sediment, benthic macroinvertebrates, and fish that are 2-9 times the level that is toxic for fish reproduction and survival. A large proportion (12.2%, or 25 times background) of juvenile largemouth bass (Micropterus salmoides, the only species examined) exhibited spinal and/or craniofacial malformations that are consistent with selenium poisoning. Teratogenic Deformity Index values indicated a 3.05% population-level impact on the bass fishery, with total selenium-induced mortality (including pre-swimup mortality) estimated to be in excess of 25% per year. These findings confirm that coal ash discharges into Herrington Lake are contributing selenium to the Lake that is poisoning fish. Copyright © 2017 Elsevier Inc. All rights reserved.

  5. 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. © The Authors 2015. Published by Oxford University Press on behalf of Entomological Society of America. All rights reserved. For Permissions, please email: journals.permissions@oup.com.

  6. Effects of discharge fluctuation and the addition of fine sediment on stream fish and macroinvertebrates below a water-filtration facility

    Science.gov (United States)

    Erman, Don C.; Ligon, Franklin K.

    1988-01-01

    A small, coastal stream in the San Francisco Bay area of California, USA, received the discharges from a drinking-water filtration plant. Two types of discharges were present. Discharges from filter backwashing were 3 4 times base stream flow, occurred 10 60 times per day, contained fine sediments, and each lasted about 10 min. The other discharge was a large, steady flow of relatively sediment-free water from occasional overflow of the delivery aqueduct which generally lasted several hours a day. Samples of invertebrates from natural substrates had significantly fewer taxa and lower density at the two stations below the backwash than at the two above. However, when stable artificial substrates were used, there were no significant differences among all four stations. The aqueduct apparently had no effect because the. invertebrate community at the station upstream of the backwash but downstream of the aqueduct was statistically similar to the station above the aqueduct. To test for acute toxicity, we exposed additional artificial substrates to short-term simulated backwash conditions. These exposures had no effect on invertebrate density or drift. Three-spine stickleback ( Gasterosteus aculeatus) populations were also significantly reduced at the two downstream stations and were made up mostly of larger, adult fish. Prickly sculpins ( Cottus asper), restricted to the most downstream station, were emaciated and had poor growth, probably as a result of scarce benthic food organisms. Artificial redds with eggs of rainbow trout ( Salmo gairdneri) had significantly lower survival at two stations below the plant backwash (30.7% and 41.8%) than at the one above it (61.4%). Hatchery rainbow trout held in cages below the treatment plant from 7 to 37 days survived and continued to feed. Thus, the major effect of the water treatment plant on fish and invertebrates probably was not from acute toxicity in the discharges or the occasionally large discharge of clean water from the

  7. Evaluation of Deposited Sediment and Macroinvertebrate Metrics Used to Quantify Biological Response to Excessive Sedimentation in Agricultural Streams

    Science.gov (United States)

    Sutherland, Andrew B.; Culp, Joseph M.; Benoy, Glenn A.

    2012-07-01

    The objective of this study was to evaluate which macroinvertebrate and deposited sediment metrics are best for determining effects of excessive sedimentation on stream integrity. Fifteen instream sediment metrics, with the strongest relationship to land cover, were compared to riffle macroinvertebrate metrics in streams ranging across a gradient of land disturbance. Six deposited sediment metrics were strongly related to the relative abundance of Ephemeroptera, Plecoptera and Trichoptera and six were strongly related to the modified family biotic index (MFBI). Few functional feeding groups and habit groups were significantly related to deposited sediment, and this may be related to the focus on riffle, rather than reach-wide macroinvertebrates, as reach-wide sediment metrics were more closely related to human land use. Our results suggest that the coarse-level deposited sediment metric, visual estimate of fines, and the coarse-level biological index, MFBI, may be useful in biomonitoring efforts aimed at determining the impact of anthropogenic sedimentation on stream biotic integrity.

  8. Identifying primary stressors impacting macroinvertebrates in the Salinas River (California, USA): Relative effects of pesticides and suspended particles

    International Nuclear Information System (INIS)

    Anderson, B.S.; Phillips, B.M.; Hunt, J.W.; Connor, V.; Richard, N.; Tjeerdema, R.S.

    2006-01-01

    Laboratory dose-response experiments with organophosphate and pyrethroid pesticides, and dose-response experiments with increasing particle loads were used to determine which of these stressors were likely responsible for the toxicity and macroinvertebrate impacts previously observed in the Salinas River. Experiments were conducted with the amphipod Hyalella azteca, the baetid mayfly Procloeon sp., and the midge Chironomus dilutus (Shobanov, formerly Chironomus tentans). The results indicate the primary stressor impacting H. azteca was pesticides, including chlorpyrifos and permethrin. The mayfly Procloeon sp. was sensitive to chlorpyrifos and permethrin within the range of concentrations of these pesticides measured in the river. Chironomus dilutus were sensitive to chlorpyrifos within the ranges of concentrations measured in the river. None of the species tested were affected by turbidity as high as 1000 NTUs. The current study shows that pesticides are more important acute stressors of macroinvertebrates than suspended sediments in the Salinas River. - Pesticides are the primary stressor impacting macroinvertebrates in sections of the lower Salinas River

  9. Identifying primary stressors impacting macroinvertebrates in the Salinas River (California, USA): Relative effects of pesticides and suspended particles

    Energy Technology Data Exchange (ETDEWEB)

    Anderson, B.S. [Department of Environmental Toxicology, University of California, Davis, CA 95616 (United States)]. E-mail: anderson@ucdavis.edu; Phillips, B.M. [Department of Environmental Toxicology, University of California, Davis, CA 95616 (United States); Hunt, J.W. [Department of Environmental Toxicology, University of California, Davis, CA 95616 (United States); Connor, V. [Division of Water Quality, State Water Resources Control Board, 1001 I. Street, Sacramento, CA 95814 (United States); Richard, N. [Division of Water Quality, State Water Resources Control Board, 1001 I. Street, Sacramento, CA 95814 (United States); Tjeerdema, R.S. [Department of Environmental Toxicology, University of California, Davis, CA 95616 (United States)

    2006-06-15

    Laboratory dose-response experiments with organophosphate and pyrethroid pesticides, and dose-response experiments with increasing particle loads were used to determine which of these stressors were likely responsible for the toxicity and macroinvertebrate impacts previously observed in the Salinas River. Experiments were conducted with the amphipod Hyalella azteca, the baetid mayfly Procloeon sp., and the midge Chironomus dilutus (Shobanov, formerly Chironomus tentans). The results indicate the primary stressor impacting H. azteca was pesticides, including chlorpyrifos and permethrin. The mayfly Procloeon sp. was sensitive to chlorpyrifos and permethrin within the range of concentrations of these pesticides measured in the river. Chironomus dilutus were sensitive to chlorpyrifos within the ranges of concentrations measured in the river. None of the species tested were affected by turbidity as high as 1000 NTUs. The current study shows that pesticides are more important acute stressors of macroinvertebrates than suspended sediments in the Salinas River. - Pesticides are the primary stressor impacting macroinvertebrates in sections of the lower Salinas River.

  10. Complex small pelagic fish population patterns arising from individual behavioral responses to their environment

    Science.gov (United States)

    Brochier, Timothée; Auger, Pierre-Amaël; Pecquerie, Laure; Machu, Eric; Capet, Xavier; Thiaw, Modou; Mbaye, Baye Cheikh; Braham, Cheikh-Baye; Ettahiri, Omar; Charouki, Najib; Sène, Ousseynou Ndaw; Werner, Francisco; Brehmer, Patrice

    2018-05-01

    Small pelagic fish (SPF) species are heavily exploited in eastern boundary upwelling systems (EBUS) as their transformation products are increasingly used in the world's food chain. Management relies on regular monitoring, but there is a lack of robust theories for the emergence of the populations' traits and their evolution in highly variable environments. This work aims to address existing knowledge gaps by combining physical and biogeochemical modelling with an individual life-cycle based model applied to round sardinella (Sardinella aurita) off northwest Africa, a key species for regional food security. Our approach focused on the processes responsible for seasonal migrations, spatio-temporal size-structure, and interannual biomass fluctuations. Emergence of preferred habitat resulted from interactions between natal homing behavior and environmental variability that impacts early life stages. Exploration of the environment by the fishes was determined by swimming capabilities, mesoscale to regional habitat structure, and horizontal currents. Fish spatio-temporal abundance variability emerged from a complex combination of distinct life-history traits. An alongshore gradient in fish size distributions is reported and validated by in situ measurements. New insights into population structure are provided, within an area where the species is abundant year-round (Mauritania) and with latitudinal migrations of variable (300-1200 km) amplitude. Interannual biomass fluctuations were linked to modulations of fish recruitment over the Sahara Bank driven by variability in alongshore current intensity. The identified processes constitute an analytical framework that can be implemented in other EBUS and used to explore impacts of regional climate change on SPF.

  11. Fishing down the largest coral reef fish species.

    Science.gov (United States)

    Fenner, Douglas

    2014-07-15

    Studies on remote, uninhabited, near-pristine reefs have revealed surprisingly large populations of large reef fish. Locations such as the northwestern Hawaiian Islands, northern Marianas Islands, Line Islands, U.S. remote Pacific Islands, Cocos-Keeling Atoll and Chagos archipelago have much higher reef fish biomass than islands and reefs near people. Much of the high biomass of most remote reef fish communities lies in the largest species, such as sharks, bumphead parrots, giant trevally, and humphead wrasse. Some, such as sharks and giant trevally, are apex predators, but others such as bumphead parrots and humphead wrasse, are not. At many locations, decreases in large reef fish species have been attributed to fishing. Fishing is well known to remove the largest fish first, and a quantitative measure of vulnerability to fishing indicates that large reef fish species are much more vulnerable to fishing than small fish. The removal of large reef fish by fishing parallels the extinction of terrestrial megafauna by early humans. However large reef fish have great value for various ecological roles and for reef tourism. Copyright © 2014 Elsevier Ltd. All rights reserved.

  12. Use of macroinvertebrates to identify cultivated wetlands in the Prairie Pothole Region

    Science.gov (United States)

    Euliss, Ned H.; Mushet, David M.; Johnson, Douglas H.

    2001-01-01

    We evaluated the use of macroinvertebrates as a potential tool to identify dry and intensively farmed temporary and seasonal wetlands in the Prairie Pothole Region. The techniques we designed and evaluated used the dried remains of invertebrates or their egg banks in soils as indicators of wetlands. For both the dried remains of invertebrates and their egg banks, we weighted each taxon according to its affinity for wetlands or uplands. Our study clearly demonstrated that shells, exoskeletons, head capsules, eggs, and other remains of macroinvertebrates can be used to identify wetlands, even when they are dry, intensively farmed, and difficult to identify as wetlands using standard criteria (i.e., hydrology, hydrophytic vegetation, and hydric soils). Although both dried remains and egg banks identified wetlands, the combination was more useful, especially for identifying drained or filled wetlands. We also evaluated the use of coarse taxonomic groupings to stimulate use of the technique by nonspecialists and obtained satisfactory results in most situations.

  13. Assessment of macroinvertebrate communities in adjacent urban stream basins, Kansas City, Missouri, metropolitan area, 2007 through 2011

    Science.gov (United States)

    Christensen, Eric D.; Krempa, Heather M.

    2013-01-01

    Macroinvertebrates were collected as part of two separate urban water-quality studies from adjacent basins, the Blue River Basin (Kansas City, Missouri), the Little Blue River and Rock Creek Basins (Independence, Missouri), and their tributaries. Consistent collection and processing procedures between the studies allowed for statistical comparisons. Seven Blue River Basin sites, nine Little Blue River Basin sites, including Rock Creek, and two rural sites representative of Missouri ecological drainage units and the area’s ecoregions were used in the analysis. Different factors or levels of urban intensity may affect the basins and macroinvertebrate community metrics differently, even though both basins are substantially developed above their downstream streamgages (Blue River, 65 percent; Little Blue River, 52 percent). The Blue River has no flood control reservoirs and receives wastewater effluent and stormflow from a combined sewer system. The Little Blue River has flood control reservoirs, receives no wastewater effluent, and has a separate stormwater sewer system. Analysis of macroinvertebrate community structure with pollution-tolerance metrics and water-quality parameters indicated differences between the Blue River Basin and the Little Blue River Basin.

  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. Multiple stress response of lowland stream benthic macroinvertebrates is dependent on habitat type

    DEFF Research Database (Denmark)

    Graeber, Daniel; Jensen, Tinna M.; Rasmussen, Jes

    2017-01-01

    Worldwide, lowland stream ecosystems are exposed to multiple anthropogenic stress due to the combination of water scarcity, eutrophication and fine sedimentation. The understanding of the effects of such multiple stress on stream benthic macroinvertebrates has been growing in the recent years...

  16. Responses of aquatic organisms to metal pollution in a lowland river in Flanders: A comparison of diatoms and macroinvertebrates

    International Nuclear Information System (INIS)

    Jonge, Maarten de; Vijver, Bart van de; Blust, Ronny; Bervoets, Lieven

    2008-01-01

    The role of macroinvertebrates and diatoms as indicator for metal pollution was investigated by assessing both biota along a metal gradient in the Belgian river the Dommel. Macroinvertebrates and diatoms were sampled in summer and winter and physical-chemical characteristics of the water were measured at four different sample periods and related to sediment characteristics. Although metal concentrations, except cadmium, in the water nowhere exceeded water quality standards, high metal concentrations were measured in the sediment, indicating historical contamination of the Dommel. At the sites that were situated downstream of the pollution source, high levels of conductivity and chloride were measured in the water. Redundancy Analysis (RDA) indicated pH, phosphate and zinc as the significant environmental variables explaining each respectively 7.7%, 11.6% and 22.6% of the macroinvertebrate community composition. Two clusters could be separated, with Gammarus pulex, Leptocerus interruptus, Baetis rhodani and Cloeon dipterum associated with low zinc concentrations and Tubificidae, Asellus aquaticus, Erpobdella sp. and Chironomus thummi-plumosus associated with higher zinc concentrations. Ammonium (10.6%), conductivity (16.5%), chloride (11.4%) and zinc (5.9%) turned out to be significant variables explaining the diatom community structure. Based on physical-chemical differences and species composition, three different groups could be separated. With this Tabellaria flocculosa and Fragilaria capucina var. rumpens were associated with low metal concentrations, Gomphonema parvulum and Nitzschia palea with elevated concentrations and Eolimna minima and Sellaphora seminulum with high zinc concentrations. In conclusion, the diatom community best reflected the metal gradient. With regard to water quality indices, those based on macroinvertebrates best followed the metal pollution gradient and were most strongly correlated with physical-chemical variables of water and

  17. Responses of aquatic organisms to metal pollution in a lowland river in Flanders: A comparison of diatoms and macroinvertebrates

    Energy Technology Data Exchange (ETDEWEB)

    Jonge, Maarten de [Department of Biology, Ecophysiology, Biochemistry and Toxicology Group, University of Antwerp, Groenenborgerlaan 171, B-2020 Antwerp (Belgium)], E-mail: maarten.dejonge@ua.ac.be; Vijver, Bart van de [Department of Bryophytes and Thallophytes, National Botanic Garden of Belgium, Domein van Bouchout, 1860 Meise (Belgium); Blust, Ronny; Bervoets, Lieven [Department of Biology, Ecophysiology, Biochemistry and Toxicology Group, University of Antwerp, Groenenborgerlaan 171, B-2020 Antwerp (Belgium)

    2008-12-15

    The role of macroinvertebrates and diatoms as indicator for metal pollution was investigated by assessing both biota along a metal gradient in the Belgian river the Dommel. Macroinvertebrates and diatoms were sampled in summer and winter and physical-chemical characteristics of the water were measured at four different sample periods and related to sediment characteristics. Although metal concentrations, except cadmium, in the water nowhere exceeded water quality standards, high metal concentrations were measured in the sediment, indicating historical contamination of the Dommel. At the sites that were situated downstream of the pollution source, high levels of conductivity and chloride were measured in the water. Redundancy Analysis (RDA) indicated pH, phosphate and zinc as the significant environmental variables explaining each respectively 7.7%, 11.6% and 22.6% of the macroinvertebrate community composition. Two clusters could be separated, with Gammarus pulex, Leptocerus interruptus, Baetis rhodani and Cloeon dipterum associated with low zinc concentrations and Tubificidae, Asellus aquaticus, Erpobdella sp. and Chironomus thummi-plumosus associated with higher zinc concentrations. Ammonium (10.6%), conductivity (16.5%), chloride (11.4%) and zinc (5.9%) turned out to be significant variables explaining the diatom community structure. Based on physical-chemical differences and species composition, three different groups could be separated. With this Tabellaria flocculosa and Fragilaria capucina var. rumpens were associated with low metal concentrations, Gomphonema parvulum and Nitzschia palea with elevated concentrations and Eolimna minima and Sellaphora seminulum with high zinc concentrations. In conclusion, the diatom community best reflected the metal gradient. With regard to water quality indices, those based on macroinvertebrates best followed the metal pollution gradient and were most strongly correlated with physical-chemical variables of water and

  18. THE INFLUENCE OF POST-FLOTATION TAILINGS POND “WARTOWICE” (LOWER SILESIA ON THE BIODIVERSITY OF MACROINVERTEBRATES

    Directory of Open Access Journals (Sweden)

    Justyna Rybak

    2013-10-01

    Full Text Available In this paper the biodiversity studies on macroinvertebrates were conducted in the area post-flotation tailings pond “Wartowice”, which poses a serious threat to the environment. The analysis of the biodiversity was done with two methods: the use of biodiversity indices along with taxonomic identification to family level and with the application of morphospecies method. Both were assessed concerning their usefulness. Macrofauna was sampled in a five sites characterized by different level of pollution. We found the dependence of macroinvertebrates structure on habitat type. Both methods, although not very accurate, were found suitable for the assessment of such disturbance type.

  19. Towards stressor-specific macroinvertebrate indices: Which traits and taxonomic groups are associated with vulnerable and tolerant taxa?

    Science.gov (United States)

    Berger, Elisabeth; Haase, Peter; Schäfer, Ralf B; Sundermann, Andrea

    2018-04-01

    Monitoring of macroinvertebrate communities is frequently used to define the ecological health status of rivers. Ideally, biomonitoring should also give an indication on the major stressors acting on the macroinvertebrate communities supporting the selection of appropriate management measures. However, most indices are affected by more than one stressor. Biological traits (e.g. size, generation time, reproduction) could potentially lead to more stressor-specific indices. However, such an approach has rarely been tested. In this study we classify 324 macroinvertebrate taxa as vulnerable (decreasing abundances) or tolerant (increasing abundances) along 21 environmental gradients (i.e. nutrients, major ions, oxygen and micropollutants) from 422 monitoring sites in Germany using Threshold Indicator Taxa Analysis (TITAN). Subsequently, we investigate which biological traits and taxonomic groups are associated with taxa classified as vulnerable or tolerant with regard to specific gradients. The response of most taxa towards different gradients was similar and especially high for correlated gradients. Traits associated with vulnerable taxa across most gradients included: larval aquatic life stages, isolated cemented eggs, reproductive cycle per year macrophytes, microphytes, silt or mud and a body size >2-4cm. Our results question whether stressor-specific indices based on macroinvertebrate assemblages can be achieved using single traits, because we observed that similar taxa responded to different gradients and also similar traits were associated with vulnerable and tolerant taxa across a variety of water quality gradients. Future studies should examine whether combinations of traits focusing on specific taxonomic groups achieve higher stressor specificity. Copyright © 2017 Elsevier B.V. All rights reserved.

  20. Response of benthic macroinvertebrate communities to highway construction in an Appalachian watershed

    Science.gov (United States)

    Hedrick, Lara B.; Welsh, S.A.; Anderson, James T.; Lin, L.-S.; Chen, Y.; Wei, X.

    2010-01-01

    Highway construction in mountainous areas can result in sedimentation of streams, negatively impacting stream habitat, water quality, and biotic communities. We assessed the impacts of construction of a segment of Corridor H, a four-lane highway, in the Lost River watershed, West Virginia, by monitoring benthic macroinvertebrate communities and water quality, before, during, and after highway construction and prior to highway use at upstream and downstream sites from 1997 through 2007. Data analysis of temporal impacts of highway construction followed a Before-After-Control-Impact (BACI) study design. Highway construction impacts included an increase in stream sedimentation during the construction phase. This was indicated by an increase in turbidity and total suspended solids. Benthic macroinvertebrate metrics indicated a community more tolerant during and after construction than in the period before construction. The percent of Chironomidae and the Hilsenhoff Biotic Index (HBI) increased, while percent of Ephemeroptera, Plecoptera, and Trichoptera (EPT) decreased. Our 10-year study addressed short-term impacts of highway construction and found that impacts were relatively minimal. A recovery of the number of EPT taxa collected after construction indicated that the benthic macroinvertebrate community may be recovering from impacts of highway construction. However, this study only addressed a period of 3 years before, 3 years during, and 4 years post construction. Inferences cannot be made concerning the long-term impacts of the highway, highway traffic, runoff, and other factors associated with highway use. Continual monitoring of the watershed is necessary to determine if the highway has a continual impact on stream habitat, water quality, and biotic integrity. ?? 2010 Springer Science+Business Media B.V.

  1. [Effects of cascading hydropower dams operation on the structure and distribution pattern of benthic macroinvertebrate assemblages in Manwan Reservoir, Southwest China].

    Science.gov (United States)

    Li, Jin Peng; Dong, Shi Kui; Peng, Ming Chun; Wu, Xuan; Zhou, Fang; Yu, Yin

    2017-12-01

    Benthic macroinvertebrate assemblages are one of the biological groups in aquatic ecosystem most sensitive to the habitat change and degradation, and can be a biological indicator for the aquatic ecosystem change and succession in cascading hydropower dam reservoir. The middle and lower reaches of the Lancang River are key spot for international biodiversity conservation and ecological studies on the effects of cascading hydropower dam exploitation. In this study, the reservoir of Manwan hydropower dam, the first dam in Lancang-Mekong river main stream, was selected as the study site. The benthic macroinvertebrate assemblages were sampled in 2011 and 2016 respectively. Meanwhile, the survey data before impounding (natural river, 1996) and early stage of single dam (1997) were collected to conduct the overall analysis for structure, distribution pattern and evolution of benthic macroinvertebrate assemblages. The results showed that the dominant biological group was gradually changed from the Oligochaeta and Insecta to the Mollusca. Along the longitudinal gradient, the density and biomass of the benthic macroinvertebrate assemblages were remarkably increased in reservoir, especially in the lacustrine zone. As for the functional feeding group, the predator and gatherer-collector changed into filter-collector predominantly in lacustrine zone. With the cascading dams operation, the biotic index indicated that the water quality of reservoir in 2016 was better than in 2011. The evolution of benthic macroinvertebrate assemblages in the Manwan Reservoir was related to the operation of Xiaowan dam in the upper reach, the hydrological regime and siltation in the reservoir, and would continue with dynamic changes with the operation of the cascading hydropower dam.

  2. 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.

  3. 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.

  4. Impact of Small Hydro-Power Plants on Salmonid Fishes Spawning Migrations

    Directory of Open Access Journals (Sweden)

    Saulius Stakėnas

    2011-04-01

    Full Text Available In 2000 and 2005, fish ladders were built in Vilnia and Siesartis rivers providing fish access to another 10 and 25 km of the rivers respectively. The analysis of redd distribution and abundance in both rivers revealed that the construction of fish ladders significantly increased the number and share of redds above dams, however, a significant increase in redds above the dam occurred 2-4 years after fish ladders construction supporting homing behaviour as one of the most important factors for the recolonization of the newly accessible habitats. The tracking of radio tagged salmon and sea trout revealed that statistically, significantly more time, fishes spent in the middle part of fish ladders. Assessed fish ladders efficiency for migrating salmonids made 66%. Minor construction defects and lack of protection were the main factors reducing fishway efficiency. Based on radio tracking data, recommendations are given for minor changes in fish ladders construction and operating schedule to increase the efficiency of fish ladders.Article in English

  5. Environmental effects of storage preservation practices: controlled flushing of fine sediment from a small hydropower reservoir.

    Science.gov (United States)

    Espa, Paolo; Castelli, Elena; Crosa, Giuseppe; Gentili, Gaetano

    2013-07-01

    Sediment flushing may be effective in mitigating loss of reservoir storage due to siltation, but flushing must be controlled to limit the impact on the downstream environment. A reliable prediction of the environmental effects of sediment flushing is hindered by the limited scientific information currently available. Consequently, there may be some controversy as regards to management decisions, planning the work, and monitoring strategies. This paper summarizes the main results of a monitoring campaign on the stream below a small alpine hydropower reservoir subjected to annual flushing between 2006 and 2009. The removed sediment was essentially silt, and the suspended solid concentration (SSC) of the discharged water was controlled to alleviate downstream impact. Control was achieved through hydraulic regulation and mechanical digging, alternating daytime sediment evacuation, and nocturnal clear water release. The four operations lasted about two weeks each and had an average SSC of about 4 g L(-1). Maximum values of SSC were generally kept below 10 g L(-1). Downstream impact was quantified through sampling of fish fauna (brown trout) and macroinvertebrate in the final reach of the effluent stream. The benthic community was severely impaired by the flushing operations, but recovered to pre-flushing values in a few months. As expected, the impact on brown trout was heavier on juveniles. While data biasing due to fish removal and re-stocking cannot be ruled out, the fish community seems to have reached a state of equilibrium characterized by a lower density than was measured before the flushing operations.

  6. Effects of changing nutrient inputs on the ratio of small pelagic fish stock and phytoplankton biomass in the Black Sea

    Science.gov (United States)

    Yunev, Oleg A.; Velikova, Violeta; Carstensen, Jacob

    2017-10-01

    Significant increases in nitrogen and phosphorus inputs to the Black Sea in the second half of the 20th century caused eutrophication and drastically decreasing Si:N and Si:P ratios. Combined with climate change, overfishing of top predators and a huge outbreak of the non-indigenous ctenophore Mnemiopsis, the pelagic food web was strongly modified and its efficiency for channeling primary production to higher trophic levels substantially reduced. We used the ratio between small pelagic fish stock and phytoplankton biomass on the Danube shelf and in the open Black Sea to investigate long-term changes in food web functioning. The ratio had 1) highest values for the pre-eutrophication period when diatoms and copepods dominated the pelagic food web ('muscle food chain'), 2) decreased during the eutrophication period with stronger prevalence of autotrophic pico- and nanophytoplankton, bacteria, heterotrophic nanoflagellates, microzooplankton, Noctiluca and jellyfish ('jelly food chain' with increased importance of the microbial loop), 3) lowest values during the ecological crisis (1989-1992), when small pelagic fish stocks collapsed, and 4) increased after 1993, indicating that the ecosystem went out of the crisis and exhibited a trend of recovery. However, in the last period (1993-2008) the ratio remained close to values observed in the middle eutrophication phase, suggesting that the ecosystem was far from fully recovered. Since early 2000s, fluctuating pelagic fish stocks, with a tendency to decreasing fish landing again, have been observed in the Black Sea. Additionally, the quality of food for the small pelagic fish has deteriorated due to warming trends and the legacy of eutrophication, giving support for the 'jelly food chain', exhibiting low energy transfer and prevalence of organisms with high respiration rate and low nutritional value.

  7. Assessment of river quality in a subtropical Austral river system: a combined approach using benthic diatoms and macroinvertebrates

    Science.gov (United States)

    Nhiwatiwa, Tamuka; Dalu, Tatenda; Sithole, Tatenda

    2017-12-01

    River systems constitute areas of high human population densities owing to their favourable conditions for agriculture, water supply and transportation network. Despite human dependence on river systems, anthropogenic activities severely degrade water quality. The main aim of this study was to assess the river health of Ngamo River using diatom and macroinvertebrate community structure based on multivariate analyses and community metrics. Ammonia, pH, salinity, total phosphorus and temperature were found to be significantly different among the study seasons. The diatom and macroinvertebrate taxa richness increased downstream suggesting an improvement in water as we moved away from the pollution point sources. Canonical correspondence analyses identified nutrients (total nitrogen and reactive phosphorus) as important variables structuring diatom and macroinvertebrate community. The community metrics and diversity indices for both bioindicators highlighted that the water quality of the river system was very poor. These findings indicate that both methods can be used for water quality assessments, e.g. sewage and agricultural pollution, and they show high potential for use during water quality monitoring programmes in other regions.

  8. Allometric relations and consequences for feeding in small pelagic fish in the Bay of Biscay

    KAUST Repository

    Bachiller, Eneko

    2012-11-21

    The body size of fish is an important factor in determining their biology and ecology, as predators eat prey smaller than themselves. Predator mouth size restricts the availability of possible prey. In this paper we provide the allometric relationships of eight common, small pelagic fish species in the Bay of Biscay. In addition, we describe the predator-prey size ratios for different species, and we determine changes in their ratio-based trophic-niche breadth with increasing body size. Results suggest that gape size does not totally determine the predator-prey size ratio distribution, but predators use the entire available prey size range, including the smallest. As they grow they simply incorporate larger prey as their increased gape size permits. Accordingly, a large degree of overlap was found in the diet composition in terms of size and predator-prey ratios, even between fish of different sizes. Of the species studied, only horse mackerels seem to be clearly specialized in relatively large prey. © 2012 International Council for the Exploration of the Sea.

  9. The impact of acid sulphate soils on water bodies and fish deaths in Finland; Happamien sulfaattimaiden aiheuttamat vesistoevaikutukset ja kalakuolemat Suomessa

    Energy Technology Data Exchange (ETDEWEB)

    Sutela, T.; Vuori, K.-M.; Louhi, P. [and others

    2012-05-15

    We have compiled in this review a comprehensive presentation of the impacts of acid sulphate soils (ASS) on water quality, biota, and fish kills in Finnish water bodies. This review is a result of extensive collaboration among research scientists in connection with the CATERMASS project co-ordinated by the Finnish Environment Institute (SYKE). Acid sulphate soils were formed in the eutrophic coastal waters of the Baltic Sea 4,000-8,000 years ago as microbes reduced the sulphate contained in saline seawater into sulphide. Sulphide clay soils emerging through land uplift have since been reclaimed and drained for cultivation use. Sulphur released in the resultant oxidation process reacted with soil water to form sulphuric acid, which draws toxic metals such as aluminium, cadmium, and copper from the soil. Heavy rains and the waters of springtime thawing transported acids and metals to the water bodies. In recent decades, the drainage depth of fields has increased because of the growing popularity of subterranean drainage methods, thus exacerbating the adverse ASS impacts on water bodies. Acidity and the attendant proliferation of toxic forms of metals induce changes in all organism groups of water biota, among them fish, macroinvertebrates, macrophytes, and bottom algae. On the specimen level, malformations have been discovered, such as structural pupae impairment in aquatic insects. The defence mechanism employed by fish against harmful substances in the surrounding water is to increase mucus exudation in the gills, which results in reduced respiration function. Exposure to acidity and metals harms the reproduction cycle of fish by delaying the development of follicles into mature eggs and by hindering eggs' fertilisation and embryo development. On the biota level, the manifestation of ASS impact is often the absence of the species or species groups most vulnerable to acidity. The species of river fish that are vulnerable to acidity include, for example

  10. 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.

  11. Importance of small fishes and invasive crayfish in otter Lutra lutra diet in an English chalk stream

    Directory of Open Access Journals (Sweden)

    Britton J. Robert

    2017-01-01

    Full Text Available The diet composition of the European otter Lutra lutra was assessed using spraint analysis in the Hampshire Avon, a lowland chalk stream in Southern England, over an 18-month period. Small cyprinid fishes were the main prey item taken in all seasons, with bullhead Cottus gobio and stone loach Barbatula barbatula also important; there were relatively few larger fishes of interest to fisheries found. There were significant seasonal differences in diet composition by season, with signal crayfish Pacifastacus leniusculus only being prominent prey items in warmer months and amphibians in winter, revealing that non-fish resources were seasonally important dietary components. Reconstructed body lengths of prey revealed the only species present in diet >350 mm was pike Esox lucius. These dietary data thus provide important information for informing conservation conflicts between otters and fishery interests.

  12. Malignant lymphoma incidentally diagnosed due to the perforation of the small intestine caused by a fish bone: A case report

    Directory of Open Access Journals (Sweden)

    Masatsugu Hiraki

    Full Text Available Introduction: The ingestion of a foreign body is relatively common. However, it rarely results in the perforation of gastrointestinal tract. We herein report an unusual case of malignant lymphoma incidentally diagnosed after the perforation of the small intestine by a fish bone. Presentation of case: A 90-year-old woman was admitted to our hospital because of abdominal pain and vomiting. Abdominal computed tomography demonstrated free air and ascites in the abdominal cavity. In the pelvic cavity, a radiopaque linear shadow about 35 mm in diameter was shown in the small intestine, and the stricture was exposed to the abdominal cavity. Therefore, a diagnosis of perforation of the small intestine due to ingestion of a foreign body and panperitonitis was made. Emergent laparotomy was performed. The intraoperative findings revealed perforation of the small intestine with a fish bone in the jejunum. Local inflammation at the perforation site was seen, and circulated wall thickness was observed at the distal side of the jejunum. Partial resection of the jejunum and anastomosis of jejuno-jejunostomy was performed. A pathological examination and immunohistochemical study of the resected specimen resulted in a diagnosis of malignant lymphoma of follicular lymphoma Grade 1. Discussion: It is very difficult to identify the existence malignancy accompanied with gastrointestinal perforation with ingestion of a foreign body. Conclusion: In cases suspected of involving malignancy, careful observation during surgery is needed in order to avoid missing the accompanying malignancy. Keywords: Fish bone, Perforation, Small intestine, Malignant lymphoma, Foreign body, Ingestion

  13. Numerical analyses of soft bottom macroinvertebrates to diagnose the pollution in tropical coastal waters

    Digital Repository Service at National Institute of Oceanography (India)

    Harkantra, S.N.; Rodrigues, N.R.

    of techniques to assess the impact of pollution on benthic community structure. Hence, to test this hypotheses some of the univariate and multivariate techniques were applied to soft bottom macro-invertebrates data of coastal waters of Mangalore, central west...

  14. Aquatic macroinvertebrates and water quality of Sandia Canyon, Los Alamos National Laboratory, December 1992--October 1993. Status report

    International Nuclear Information System (INIS)

    Cross, S.

    1994-09-01

    In the summer of 1990, an accidental spill from the TA-3 Power Plant Environment Tank released more than 3,785 liters of sulfuric acid into upper Sandia Canyon. The Biological Resource Evaluation Team (BRET) of EM-8 at Los Alamos National Laboratory (LANL) has collected aquatic samples from the stream within Sandia Canyon since then. These field studies gather water quality measurements and collect macroinvertebrates from permanent sampling sites. An earlier report by Bennett (1994) discusses previous BRET aquatic studies in Sandia Canyon. This report updates and expands Bennett's initial findings. During 1993, BRET collected water quality data and aquatic macroinvertebrates at five permanent stations within the canyon. The substrates of the upper three stations are largely sands and silts while the substrates of the two lower stations are largely rock and cobbles. The two upstream stations are located near outfalls that discharge industrial and sanitary waste effluent. The third station is within a natural cattail marsh, approximately 0.4 km (0.25 mi) downstream from Stations SC1 and SC2. Water quality parameters are slightly different at these first three stations from those expected of natural streams, suggesting slightly degraded water quality. Correspondingly, the macroinvertebrate communities at these stations are characterized by low diversities and poorly-developed community structures. The two downstream stations appear to be in a zone of recovery, where water quality parameters more closely resemble those found in natural streams of the area. Macroinvertebrate diversity increases and community structure becomes more complex at the two lower stations, which are further indications of improved water quality downstream

  15. Improving the productivity of imported dairy cattle on small-holder farms in Morocco through supplementation with fish silage blocks

    International Nuclear Information System (INIS)

    Guerouali, A.

    1999-01-01

    The present study was designed to identify problems that lower the productivity of imported dairy cattle in Morocco. For this purpose, a comprehensive survey was carried out on 8 small-holder farms over a period of two years. Analysis of the data collected indicated that in most of the herds reproductive performance was adequate (calving intervals ranging from 338 ± 11 to 420 ± 31 and services to conception ranging from 1.14 ± 0.13 to 1.91 ± 0.3), but the animals had difficulty in meeting the nutrient requirements for milk production. Although some farmers provided supplements to their animals they were either expensive or not available at the required time. One possible way of alleviating the problem was the introduction of a fish by-product into the dairy cattle ration. Two experiments were conducted, one at the Institute experimental farm and the other at a private farm selected for the survey. In both experiments, fish silage blocks were incorporated into the ration of dairy cattle in replacement of an equal amount of the most commonly used supplements. The introduction of fish silage blocks in the ration did not affect their intake or body condition. In addition, the yield and quality of the milk were maintained. This substitution allowed the farmer to utilize by-products from the fish industry which are readily available and less costly than most conventional supplementary feeds. It is concluded, that the proposed utilization of fish silage blocks will reduce the production costs and improve the economic efficiency of the small-holder farms. (author)

  16. Poisoning - fish and shellfish

    Science.gov (United States)

    Fish poisoning; Dinoflagellate poisoning; Seafood contamination; Paralytic shellfish poisoning; Ciguatera poisoning ... algae and algae-like organisms called dinoflagellates. Small fish that eat the algae become contaminated. If larger ...

  17. 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.

  18. Effects of anthropogenic silt on aquatic macroinvertebrates and abiotic variables in streams in the Brazilian Amazon

    Energy Technology Data Exchange (ETDEWEB)

    Couceiro, Sheyla Regina Marques; Hamada, Neusa [Inst. Nacional de Pesquisas da Amazonia, Coordenacao de Pesquisas em Entomologia, Manaus, AM (Brazil); Forsberg, Bruce Rider [Inst. Nacional de Pesquisas da Amazonia, Coordenacao de Pesquisas em Entomologia, Manaus, AM (Brazil); Inst. Nacional de Pesquisas da Amazonia, Coordenacao de Pesquisas em Ecologia, Manaus, AM (Brazil); Padovesi-Fonseca, Claudia [Univ. de Brasilia, Dept. de Ecologia, Brasilia, DF (Brazil)

    2010-01-15

    Purpose: While environmental risks associated with petroleum extraction such as oil spills or leaks are relatively well known, little attention has been given to the impacts of silt. The increase in petroleum exploitation in Amazonia has resulted in sediment input to aquatic systems, with impacts on their biodiversity. Here we use a combination of field measurements and statistical analyses to evaluate the impacts of anthropogenic silt derived from the construction of roads, borrow pits, and wells during the terrestrial development of gas and oil, on macroinvertebrate communities in streams of the Urucu Petroleum Province in the Central Brazilian Amazon. Material and methods: Ten impacted and nine non-impacted streams were sampled in January, April, and November of 2007. Macroinvertebrates were sampled along a 100-m continuous reach in each stream at 10-m intervals using a dip net. Abiotic variables including, a siltation index (SI), suspended inorganic sediment (SIS), sediment color index (SCI), suspend organic sediment (SOS), pH, electrical conductivity, dissolved oxygen, temperature, water velocity, channel width, and depth, were measured at three equidistant points in each stream ({proportional_to}30-m intervals). Results and discussion: SI did not differ between impacted and undisturbed streams. SIS was higher and SCI lower (more reddish) in impacted than in non-impacted streams. SCI had a positive and SIS a negative effect on both macroinvertebrate richness and density. SIS and SCI also influenced macrophyte taxonomic composition. In impacted streams, taxonomic richness and density were 1.5 times lower than in non-impacted streams. No taxon was significantly associated with impacted streams. SIS was positively correlated with SOS and electrical conductivity while SCI was negatively correlated with SOS, electrical conductivity, and pH. The lack of difference in SI between impacted and nonimpacted streams suggests that anthropogenic sediment does not accumulate

  19. Intraguild predation between small pelagic fish in the Bay of Biscay: impact on anchovy (Engraulis encrasicolus L.) egg mortality

    KAUST Repository

    Bachiller, Eneko

    2015-05-12

    Small pelagic fish can play an important role in various ecosystems linking lower and upper trophic levels. Among the factor behind the observed inter-annual variations in small pelagic fish abundance, intra- and inter-specific trophic interactions could have a strong impact on the recruitment variability (e.g. anchovy). Egg cannibalism observed in anchovies has been postulated to be a mechanism that determines the upper limit of the population density and self-regulates the population abundance of the species. On the other hand, predation by other guild species is commonly considered as a regulation mechanism between competing species. This study provides empirical evidence of anchovy cannibalism and predation of the main small pelagic fish species on anchovy eggs and estimates the effect of intraguild predation on the anchovy egg mortality rate. Results show that, depending on the year (2008–2009), up to 33 % of the total anchovy egg mortality was the result of sardine predation and up to 4 % was the result of egg cannibalism together with predation by Atlantic and Atlantic Chub mackerel and sprat. Results also indicate that in the Bay of Biscay, fluctuations in the survival index of the early life stages of anchovy are likely to be attributable at least in part to egg cannibalism and especially to a high sardine predation on anchovy eggs. © 2015 Springer-Verlag Berlin Heidelberg

  20. Aquatic macroinvertebrates of Batalha river reservoir for water captation and supply of the city of Bauru, SP, Brazil

    Directory of Open Access Journals (Sweden)

    Diana Calcidoni Moreira

    2009-08-01

    Full Text Available In this study the composition and diversity of aquatic macroinvertebrates were evaluated in the reservoir of water captation of Batalha river for treatment and supplying of the city of Bauru. The samples were collected in dry (from June to August, 2005 and rainy (from December, 2005 to February, 2006 seasons. We analyzed and identified 840 organisms belonging to 8 taxa in dry season and 4 taxa in rainy season. The system presented low abundance and diversity of macroinvertebrates probably due to the water quality and its physical and chemical variations associated with rain events.

  1. Determination of metal balance shift induced in small fresh water fish by X-ray irradiation using PIXE analysis

    International Nuclear Information System (INIS)

    Yukawa, M.; Aoki, K.; Iso, H.; Kodama, K.; Imaseki, H.; Ishikawa, Y.

    2005-01-01

    In the environmental pollution studies, it is very important to detect not only pollutants but also changes induced in organisms in the environment with various environmental stresses such as heavy metal toxicity radiation and agricultural chemicals. In the latter, monitoring is carried out using biological indicators to find out the changes, which have wide spectra from visible like deformity of the body to invisible such as changes in some enzyme activities. Changes of the balance of essential elements could occur in organisms to deal with the stresses. If we detect an elemental balance shift, we may see the environmental pollution in its early stages. Moreover, in the actual environment, combined effects, additive or reductive with coexistent elements or other stresses, is an important subject for investigation. Therefore, measurement of many elements in the biological indicator's simultaneously and determination of the distribution in the organisms are useful in clarifying the action of pollutants at sublethal levels. A small fresh water fish, Medaka can be used as one of the biological-indicators for determination of water quality. In the National Institute of Radiological Sciences (NIRS), an inbred strain of Medaka Orizias laptipes was established and has been maintained for the research purposes. Since the genetic background of inbred animals is almost uniform, the individual deviation among animals is very small. This characteristic is very useful to investigate the physiological effects of environmental stresses. We have continued to investigate the balance shift of essential elements induced in the bodies of Medaka by several stresses. In this paper, elemental content in various organs of the X-ray irradiated fish determined by PIXE method are reported in comparison with that of the control fish to observe the effect of the X-rays. Body size of Medaka is about 3 cm long, and the internal organs are very small (about l mm on average). PIXE is the most

  2. ALK-FISH borderline cases in non-small cell lung cancer: Implications for diagnostics and clinical decision making.

    Science.gov (United States)

    von Laffert, Maximilian; Stenzinger, Albrecht; Hummel, Michael; Weichert, Wilko; Lenze, Dido; Warth, Arne; Penzel, Roland; Herbst, Hermann; Kellner, Udo; Jurmeister, Philipp; Schirmacher, Peter; Dietel, Manfred; Klauschen, Frederick

    2015-12-01

    Fluorescence in-situ hybridization (FISH) for the detection of ALK-rearrangements in non-small cell lung cancer (NSCLC) is based on at first sight clear cut-off criteria (≥15% of tumor cells) for split signals (SS) and single red signals (SRS). However, NSCLC with SS-counts around the cut-off may cause interpretation problems. Tissue microarrays containing 753 surgically resected NSCLCs were independently tested for ALK-alterations by FISH and immunohistochemistry (IHC). Our analysis focused on samples with SS/SRS in the range between 10% and 20% (ALK-FISH borderline group). To better understand the role of these samples in routine diagnostics, we performed statistical analyses to systematically estimate the probability of ALK-FISH-misclassification (false negative or positive) for different numbers of evaluated tumor cell nuclei (30, 50, 100, and 200). 94.3% (710/753) of the cases were classified as unequivocally (FISH-negative (93%; 700/753) or positive (1.3%; 10/753) and showed concordant IHC results. 5.7% (43/753) of the samples showed SS/SRS between 10% and 20% of the tumor cells. Out of these, 7% (3/43; ALK-FISH: 14%, 18% and 20%) were positive by ALK-IHC, while 93% (40/43) had no detectable expression of the ALK-protein. Statistical analysis showed that ALK-FISH misclassifications occur frequently for samples with rearrangements between 10% and 20% if ALK-characterization is based on a sharp cut-off point (15%). If results in this interval are defined as equivocal (borderline), statistical sampling-related ALK-FISH misclassifications will occur in less than 1% of the cases if 100 tumor cells are evaluated. While ALK status can be determined robustly for the majority of NSCLC by FISH our analysis showed that ∼6% of the cases belong to a borderline group for which ALK-FISH evaluation has only limited reliability due to statistical sampling effects. These cases should be considered equivocal and therapy decisions should include additional tests and clinical

  3. A systematic review of the effectiveness of liming to mitigate impacts of river acidification on fish and macro-invertebrates

    International Nuclear Information System (INIS)

    Mant, Rebecca C.; Jones, David L.; Reynolds, Brian; Ormerod, Steve J.; Pullin, Andrew S.

    2013-01-01

    The addition of calcium carbonate to catchments or watercourses – liming – has been used widely to mitigate freshwater acidification but the abatement of acidifying emissions has led to questions about its effectiveness and necessity. We conducted a systematic review and meta-analysis of the impact of liming streams and rivers on two key groups of river organisms: fish and invertebrates. On average, liming increased the abundance and richness of acid-sensitive invertebrates and increased overall fish abundance, but benefits were variable and not guaranteed in all rivers. Where B-A-C-I designs (before-after-control-impact) were used to reduce bias, there was evidence that liming decreased overall invertebrate abundance. This systematic review indicates that liming has the potential to mitigate the symptoms of acidification in some instances, but effects are mixed. Future studies should use robust designs to isolate recovery due to liming from decreasing acid deposition, and assess factors affecting liming outcomes. -- Highlights: •In a systematic review and meta-analysis, we asked how river liming affected fish and invertebrates. •On average, liming increased fish abundance. •Liming also increased average abundance and richness of acid-sensitive invertebrates. •However, benefits were variable and not guaranteed in all acidified rivers. -- A systematic review showed lime application to acidified rivers increased average fish abundance, and abundance and richness in acid-sensitive invertebrates, but not always

  4. Assessing disruption of longitudinal connectivity on macroinvertebrate assemblages in a semiarid lowland river

    Directory of Open Access Journals (Sweden)

    Marta Leiva

    2017-12-01

    Full Text Available Abstract Aim: Our aim in this study was evaluate the effects of flow regulation for irrigation on the macroinvertebrate assemblages in a semiarid river. Methods We sampled two reaches in Dulce River; one placed upstream a weir that diverts flow into a network of irrigation channels and the other downstream that weir, in the assessment of the fluvial discontinuity. We assess the differences among reaches and sites, environmental variables, invertebrate density, richness and Shannon-Wiener index applying non-parametric analyses of variance Kruskal Wallis. The similarity percentage analysis (SIMPER was used to identify which species contributed to the dissimilarities on macroinvertebrate assemblage structure. Canonical Correspondence Analysis (CCA was performed with the total set of samples to explore macroinvertebrate distribution in reaches and associations of the assemblages with habitat variables. Results The density, richness and Shannon index values did not show differences between the reaches located upstream and downstream. Beta diversity (Whittaker was 0.72 among upstream sites, 0.56 among downstream sites and higher species turnover (0.73 was obtained between both reaches. The Canonical Correspondence Analysis explained 46.71% of the variance differentiating upstream sites explained by higher values of organic matter of bottom sediments and discharge, high density of Nais communis, Bothrioneurum americanum, Pelomus, Stephensoniana trivandrana, Pristina menoni, P. jenkinae, P.longidentata, P. americana, Dero obtusa, Endotribelos, Heleobia and Turbellaria. The downstream sites were associated to coarser substratum and higher density of Lopescladius, Polypedilum, Cricotopus, Thienamaniella, Cryptochironomus, Baetidae, Nematoda and Corbicula fluminea. Conclusions The low-flow disturbance had effects on the composition of the benthic invertebrate assemblages, but attributes (such as density and richness showed a lower variability probably

  5. Beyond classic ecological assessment: The use of functional indices to indicate fish assemblages sensitivity to human disturbance in estuaries.

    Science.gov (United States)

    Teichert, Nils; Lepage, Mario; Lobry, Jérémy

    2018-05-22

    Assessing ecological health of aquatic ecosystems is crucial in the current context of biodiversity loss to guide and prioritize management actions. Although several fish-based indices were developed to assess the ecological status of estuarine ecosystems, they do not provide guidance on the causal responses of communities to disturbances. The functional trait-based approach provides an understanding of how human disturbance affects the composition of biological and ecological traits in assemblages, as well as their consequences for ecosystem functioning. Here, we evaluate the responses of fish assemblages to human disturbance in 30 French estuaries using several taxonomic and functional indices (e.g. diversity, evenness or redundancy). We tested whether these indices can provide additional information on the human impacts and health of assemblages that are not reflected by the ecological indicator (fish-based index ELFI). Results indicated that high values of local human disturbances were associated to a decrease in fish abundance, decrease in species richness and reduced functional redundancy, whereas taxonomic and functional evenness increased. In contrast, the functional richness remained stable suggesting that the functional traits of species removed by stressors were maintained by more tolerant species. Indeed, we found that the local disturbances mainly resulted in a decrease in the proportions of small benthic species feeding on macro-invertebrates, which were dominant in the studied estuaries. Some functional alterations were detected by the fish-based index, but the decline of functional redundancy was not reflected, highlighting a serious concern for management. Indeed, the abrupt collapse of functional redundancy in response to local disturbances can decrease the ability of assemblages to maintain certain species traits in the face of future environmental disturbance, including climate change. From a management perspective, the application of such

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

    International Nuclear Information System (INIS)

    Bryer, Pamela J.; Scoggins, Mateo; McClintock, Nancy L.

    2010-01-01

    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.

  7. La Popala creek: quality analysis of water from some physical - chemical, microbiological variables and aquatic macroinvertebrates

    International Nuclear Information System (INIS)

    Milan Valoyes, Wandy Yohanna; Caicedo Quintero, Orlando; Aguirre Ramirez, Nestor Jaime

    2011-01-01

    The Popala creek supplies water to the people of Bolombolo in Venecia municipality in Antioquia, Colombia. In November 14th and 28th of 2009, four sampling station were located along the creek, to measure five sets of variables: physico- chemical, microbiological, aquatic macroinvertebrate, biological indicators and biotic index BMWP.Physico- chemical variables, aquatic macroinvertebrates and index BMWP indicate good environmental conditions in station 2, located about 150 m from the headwaters (station 1). On the other hand, Station 4, located near to the Cauca River, exhibits deterioration in water quality. Stations 3 and 4 displayed high levels of fecal coliforms. However, the samples taken from Bolombolo's water supply network indicate the water of the aqueduct is adequate for human consumption.

  8. Hydrological cycle effects on the aquatic community in a Neotropical stream of the Andean piedmont during the 2007-2010 ENSO events.

    Science.gov (United States)

    Ríos-Pulgarín, M I; Barletta, M; Mancera-Rodriguez, N J

    2016-07-01

    The seasonal and interannual changes in the fish, macroinvertebrates and phycoperiphyton assemblages of the Guarinó River 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. Four samplings (in dry and rainy seasons) were performed per year. Environmental variables (temperature, pH, conductivity, turbidity, oxygen, total nitrogen, orthophosphate, depth and flow rate) were measured. The temporal patterns of the taxonomic compositions for the three assemblages and the functional composition of fish and macroinvertebrate assemblages with respect to environmental variables were examined through canonical discriminant analysis, multidimensional scaling and multiple correlations. The presence and abundance of fishes, macroinvertebrates and algae species were regulated by environmental variables associated with extreme hydrological events, which derived from the natural torrential regimen of the basin and larger-scale phenomena, such as El Niño and La Niña. Fish abundance and richness were significantly correlated with algal density and pH, the macroinvertebrate density was negatively related to the flow rate and the richness was positively correlated with algal density. The algae richness was positively correlated with pH and negatively correlated with the flow rate and nitrogen. The algal density was positively correlated with pH and temperature and negatively correlated with river flow. The phycoperiphyton assemblage exhibited more direct responses in its density and richness to the hydrological changes (r(2) = 0·743 and 0·800, respectively). In functional terms, the El Niño phenomenon was defined by a greater abundance of omnivorous and insectivorous fishes, as well as filter feeders, scrapers and macroinvertebrate predators. During La Niña, a greater abundance of benthic fishes (both detritivorous and insectivorous) and

  9. Experimental acidification of two biogeochemically-distinct neotropical streams: Buffering mechanisms and macroinvertebrate drift

    International Nuclear Information System (INIS)

    Ardón, Marcelo; Duff, John H.; Ramírez, Alonso; Small, Gaston E.; Jackman, Alan P.; Triska, Frank J.; Pringle, Catherine M.

    2013-01-01

    Research into the buffering mechanisms and ecological consequences of acidification in tropical streams is lacking. We have documented seasonal and episodic acidification events in streams draining La Selva Biological Station, Costa Rica. Across this forested landscape, the severity in seasonal and episodic acidification events varies due to interbasin groundwater flow (IGF). Streams that receive IGF have higher concentrations of solutes and more stable pH (∼ 6) than streams that do not receive IGF (pH ∼ 5). To examine the buffering capacity and vulnerability of macroinvertebrates to short-term acidification events, we added hydrochloric acid to acidify a low-solute, poorly buffered (without IGF) and a high-solute, well buffered stream (with IGF). We hypothesized that: 1) protonation of bicarbonate (HCO 3 − ) would neutralize most of the acid added in the high-solute stream, while base cation release from the sediments would be the most important buffering mechanism in the low-solute stream; 2) pH declines would mobilize inorganic aluminum (Ali) from sediments in both streams; and 3) pH declines would increase macroinvertebrate drift in both streams. We found that the high-solute stream neutralized 745 μeq/L (96% of the acid added), while the solute poor stream only neutralized 27.4 μeq/L (40%). Protonation of HCO 3 − was an important buffering mechanism in both streams. Base cation, Fe 2+ , and Ali release from sediments and protonation of organic acids also provided buffering in the low-solute stream. We measured low concentrations of Ali release in both streams (2-9 μeq/L) in response to acidification, but the low-solute stream released double the amount Ali per 100 μeq of acid added than the high solute stream. Macroinvertebrate drift increased in both streams in response to acidification and was dominated by Ephemeroptera and Chironomidae. Our results elucidate the different buffering mechanisms in tropical streams and suggest that low

  10. Macroinvertebrate-based assessment of biological condition at selected sites in the Eagle River watershed, Colorado, 2000-07

    Science.gov (United States)

    Zuellig, Robert E.; Bruce, James F.; Healy, Brian D.; Williams, Cory A.

    2010-01-01

    The U.S. Geological Survey (USGS), in cooperation with the Colorado River Water Conservation District, Eagle County, Eagle River Water and Sanitation District, Upper Eagle Regional Water Authority, Colorado Department of Transportation, City of Aurora, Town of Eagle, Town of Gypsum, Town of Minturn, Town of Vail, Vail Resorts, Colorado Springs Utilities, Denver Water, and the U.S. Department of Agriculture Forest Service (FS), compiled macroinvertebrate (73 sites, 124 samples) data previously collected in the Eagle River watershed from selected USGS and FS studies, 2000-07. These data were analyzed to assess the biological condition (that is, biologically ?degraded? or ?good?) at selected sites in the Eagle River watershed and determine if site class (for example, urban or undeveloped) described biological condition. An independently developed predictive model was applied to calculate a site-specific measure of taxonomic completeness for macroinvertebrate communities, where taxonomic completeness was expressed as the ratio of observed (O) taxa to those expected (E) to occur at each site. Macroinvertebrate communities were considered degraded at sites were O/E values were less than 0.80, indicating that at least 20 percent of expected taxa were not observed. Sites were classified into one of four classes (undeveloped, adjacent road or highway or both, mixed, urban) using a combination of riparian land-cover characteristics, examination of topographic maps and aerial imagery, screening for exceedances in water-quality standards, and best professional judgment. Analysis of variance was used to determine if site class accounted for variability in mean macroinvertebrate O/E values. Finally, macroinvertebrate taxa observed more or less frequently than expected at urban sites were indentified. This study represents the first standardized assessment of biological condition of selected sites distributed across the Eagle River watershed. Of the 73 sites evaluated, just over

  11. Spatial variation of macroinvertebrate community structure and associated environmental conditions in a subtropical river system of southeastern China

    Directory of Open Access Journals (Sweden)

    Fu L.

    2015-01-01

    Full Text Available Knowledge of macroinvertebrate distributions and associated environmental drivers in subtropical Asian rivers is relatively scarce. To fill this knowledge gap, we examined the spatial variation of macroinvertebrate community structure and associated environmental conditions in a subtropical river system, the Dongjiang River Basin, in southeastern China. A total of 70 families and 9 classes of macroinvertebrates were identified from 74 sites sampled in January 2013. Our study has the following findings: (1 a distinct spatial differentiation of macroinvertebrate communities was present in the Dongjiang River Basin indicated by non-metric multidimensional scaling (NMDS, which corresponded to the northern region (NR, middle region (MR, and southern region (SR gradient; (2 ANOVAs showed that diversity indices (total taxa, Margalef index and the Shannon diversity index, biotic indices (richness of EPT, percentage of EPT, and family biotic index and most of the studied environmental conditions (elevation, slope, steam order, water temperature, electrical conductivity, dissolved oxygen, pH, substrates, ammoniacal nitrogen, total phosphorus, percentage of urban land, percentage of rural land, and percentage of forest land differed significantly among the three regions and a degradation gradient was observed in the NR–MR–SR direction; (3 Canonical correspondence analysis (CCA revealed that NR sites were characterized by steep slope and coarse substrate, MR sites were characterized by high water temperatures and shallow slopes, and SR sites were primarily characterized by high total phosphorus and ammoniacal nitrogen concentrations; and (4 the Indicator Species Analysis, in conjunction with CCA analysis indicated that the most representative indicator taxon is Tipulidae for NR, Semisulcospira sp. for MR, and Branchiura sp. for SR.

  12. Are the streams of the Sinos River basin of good water quality? Aquatic macroinvertebrates may answer the question

    Directory of Open Access Journals (Sweden)

    L. Bieger

    Full Text Available Macroinvertebrate communities are one of the most used groups in assessments of water quality, since they respond directly to the level of contamination of aquatic ecosystems. The main objective of this study was the assessment of the water quality of the Sinos River basin (Rio Grande do Sul state, Brazil through biotic indices based on the macroinvertebrate community ("Family Biotic Index - FBI", and "Biological Monitoring Working Party Score System - BMWP". Three lower order streams (2nd order were selected in each one of three main regions of the basin. In each stream, the samplings were performed in three reaches (upper, middle, and lower, totalling 27 reaches. Two samplings were carried in each reach over one year (winter and summer. A total of 6,847 macroinvertebrates distributed among 54 families were sampled. The streams from the upper region were of better water quality than the lower region. The water quality did not change between the upper, middle and lower reaches of the streams. However, the upper reaches of the streams were of better water quality in all the regions of the basin. The water quality of the streams did not vary between the summer and the winter. This result demonstrated that water quality may be analysed in both studied seasons (summer and winter using biotic indices. The analysis of the results allows us to conclude that the biotic indices used reflected the changes related to the water quality along the longitudinal gradient of the basin. Thus, aquatic macroinvertebrates were important bioindicators of the water and environmental quality of the streams of the Sinos River basin.

  13. High-resolution 1H NMR spectroscopy of fish muscle, eggs and small whole fish via Hadamard-encoded intermolecular multiple-quantum coherence.

    Directory of Open Access Journals (Sweden)

    Honghao Cai

    Full Text Available BACKGROUND AND PURPOSE: Nuclear magnetic resonance (NMR spectroscopy has become an important technique for tissue studies. Since tissues are in semisolid-state, their high-resolution (HR spectra cannot be obtained by conventional NMR spectroscopy. Because of this restriction, extraction and high-resolution magic angle spinning (HR MAS are widely applied for HR NMR spectra of tissues. However, both of the methods are subject to limitations. In this study, the feasibility of HR (1H NMR spectroscopy based on intermolecular multiple-quantum coherence (iMQC technique is explored using fish muscle, fish eggs, and a whole fish as examples. MATERIALS AND METHODS: Intact salmon muscle tissues, intact eggs from shishamo smelt and a whole fish (Siamese algae eater are studied by using conventional 1D one-pulse sequence, Hadamard-encoded iMQC sequence, and HR MAS. RESULTS: When we use the conventional 1D one-pulse sequence, hardly any useful spectral information can be obtained due to the severe field inhomogeneity. By contrast, HR NMR spectra can be obtained in a short period of time by using the Hadamard-encoded iMQC method without shimming. Most signals from fatty acids and small metabolites can be observed. Compared to HR MAS, the iMQC method is non-invasive, but the resolution and the sensitivity of resulting spectra are not as high as those of HR MAS spectra. CONCLUSION: Due to the immunity to field inhomogeneity, the iMQC technique can be a proper supplement to HR MAS, and it provides an alternative for the investigation in cases with field distortions and with samples unsuitable for spinning. The acquisition time of the proposed method is greatly reduced by introduction of the Hadamard-encoded technique, in comparison with that of conventional iMQC method.

  14. Zebrafish response to robotic fish: preference experiments on isolated individuals and small shoals

    International Nuclear Information System (INIS)

    Polverino, G; Abaid, N; Kopman, V; Porfiri, M; Macrì, S

    2012-01-01

    Recently developed bioinspired robots imitate their live counterparts in both aspect and functionality. Nevertheless, whether these devices can be integrated within the ecological niche inspiring their design is seldom tested experimentally. An elemental research question concerns the feasibility of modulating spontaneous behaviour of animal systems through bioinspired robotics. The following study explores the possibility of engineering a robotic fish capable of influencing the behaviour of live zebrafish (Danio rerio) in a dichotomous preference test. While we observe that the preference for the robotic fish never exceeds the preference for a conspecific, our data show that the robot is successful in attracting both isolated individuals and small shoals and that such capability is influenced by its bioinspired features. In particular, we find that the robot's undulations enhance its degree of attractiveness, despite the noise inherent in the actuation system. This is the first experimental evidence that live zebrafish behaviour can be influenced by engineered robots. Such robotic platforms may constitute a valuable tool to investigate the bases of social behaviour and uncover the fundamental determinants of animal functions and dysfunctions. (paper)

  15. Pollution evaluation in the Shahrood River: Do physico-chemical and macroinvertebrate-based indices indicate same responses to anthropogenic activities?

    Science.gov (United States)

    Sharifinia, Moslem; Mahmoudifard, Abbas; Imanpour Namin, Javid; Ramezanpour, Zohreh; Yap, Chee Kong

    2016-09-01

    This study evaluates the impact of anthropogenic activities on the Shahrood River using water physico-chemical variables and macroinvertebrates data sets obtained over a period of 12 months between February 2012 and February 2013 at 8 sampling sites. Biotic indices i.e. FBI and BMWP based on macroinvertebrates and physico-chemical indices (MPI, HPI and NSF-WQI) were employed to evaluate the water quality status in connection with natural- and human-induced pressures. Based on physico-chemical indices, water quality was categorized as low polluted level and it is suitable for drinking purposes. The water quality based on biotic indices was related to the anthropic activities; a clear deterioration of the water quality was observed from upstream to downstream sites. The water quality along the river changed from very good (class I; reference sites) to good (class II; midstream sites) and turned into moderate (class III) and poor (class IV) quality (downstream sites). These findings indicate that biotic indices are more powerful indicators in assessing water quality than physico-chemical indices. Allocapnia, Glossosoma and Hesperoperla were exclusively related to least disturbed sites, and Naididae, Orthocladiinae and Ecdyonurus were found in sites showing notable degradation. Our results recommended that the use of macroinvertebrates could be employed as a cost-effective tool for biomonitoring and controlling of polluted riverine ecosystems in the Middle East. Finally, the results from this study may be useful not only for developing countries, but also for any organization struggling to use macroinvertebrate based indices with restricted financial resources and knowledge. Copyright © 2016 Elsevier Ltd. All rights reserved.

  16. Disturbance caused by freshwater releases of different magnitude on the aquatic macroinvertebrate communities of two coastal lagoons

    Science.gov (United States)

    Cañedo-Argüelles, Miguel; Rieradevall, Maria

    2010-06-01

    The response of the aquatic macroinvertebrate communities to freshwater releases of different magnitude and persistence was investigated in two Mediterranean coastal lagoons (Ca l'Arana and Ricarda). The study was carried out during 14 months (June 2004-July 2005) in which different environmental variables and the macroinvertebrate communities associated with two different habitats, the Phragmites australis belt and the deep area of the lagoons, were sampled monthly. Additionally, potential colonizing sources were identified through the analysis of Chironomidae pupal exuviae. The initial response of the communities to the freshwater releases was similar, being characterized by a peak of opportunistic taxa (mainly Naididae), but the late response was different for each lagoon. In the Ca l'Arana, the magnitude of the freshwater release was higher (salinity dropped below five, which is the limit commonly established for most freshwater species) and its persistence was also higher, allowing the colonization of the lagoon by new insect taxa, which replaced the brackish water species. In the Ricarda, the salinity never dropped beyond five and pre-disturbance conditions were rapidly re-established. This, together with the acclimatizing mechanisms showed by the species Chironomus riparius and Hediste diversicolor, permitted the recovery of the pre-disturbance macroinvertebrate community.

  17. Richness and density of aquatic benthic macroinvertebrates after exposure to fungicides and insecticides in rice paddy fields

    Directory of Open Access Journals (Sweden)

    ALANA C.D. WANDSCHEER

    Full Text Available ABSTRACT The objective of this study was to verify the richness and density of aquatic benthic macroinvertebrates after exposure to fungicides and insecticides of the rice paddy fields. In the crop seasons of 2012/13 and 2013/14, field experiments were performed, which consisted of single-dose applications of the fungicides trifloxystrobin + tebuconazole and tricyclazole, and the insecticides lambda-cyhalothrin + thiamethoxam and diflubenzuron, in 10 m2 experimental plots, over rice plants in the R3 stage. Control plots with and without rice plants were maintained in order to simulate a natural environment. Soil samples were collected during rice cultivation for assessment of the macroinvertebrate fauna. Chemical-physical parameters assessed in the experiments included temperature, pH and oxygen dissolved in the water and pesticide persistence in the water and in the soil. The application of a single dose of the pesticides and fungicides in the recommended period does not cause significant negative effects over the richness and density of the macroinvertebrates. Tebuconazole, tricyclazole and thiamethoxam showed high persistence in the irrigation water of rice paddy fields. Thus, the doses and number of applications of these products in crops should be carefully handled in order to avoid contamination of the environment.

  18. Richness and density of aquatic benthic macroinvertebrates after exposure to fungicides and insecticides in rice paddy fields.

    Science.gov (United States)

    Wandscheer, Alana C D; Marchesan, Enio; Santos, Sandro; Zanella, Renato; Silva, Marília F; Londero, Guilherme P; Donato, Gabriel

    2017-01-01

    The objective of this study was to verify the richness and density of aquatic benthic macroinvertebrates after exposure to fungicides and insecticides of the rice paddy fields. In the crop seasons of 2012/13 and 2013/14, field experiments were performed, which consisted of single-dose applications of the fungicides trifloxystrobin + tebuconazole and tricyclazole, and the insecticides lambda-cyhalothrin + thiamethoxam and diflubenzuron, in 10 m2 experimental plots, over rice plants in the R3 stage. Control plots with and without rice plants were maintained in order to simulate a natural environment. Soil samples were collected during rice cultivation for assessment of the macroinvertebrate fauna. Chemical-physical parameters assessed in the experiments included temperature, pH and oxygen dissolved in the water and pesticide persistence in the water and in the soil. The application of a single dose of the pesticides and fungicides in the recommended period does not cause significant negative effects over the richness and density of the macroinvertebrates. Tebuconazole, tricyclazole and thiamethoxam showed high persistence in the irrigation water of rice paddy fields. Thus, the doses and number of applications of these products in crops should be carefully handled in order to avoid contamination of the environment.

  19. Temporally variable macroinvertebrate-stone relationships in streams

    DEFF Research Database (Denmark)

    Jacobsen, D.

    2005-01-01

    of fauna parameter and stone variable from different sampling dates (n=9-11) were rarely correlated to any of the measures of stream stability, this study has demonstrated high temporal variability in fauna-stone relationships (CV's of regression slopes). Consequently, temporally un-replicated studies......Stones were used to sample macroinvertebrates and characterise microhabitats at monthly or bimonthly intervals in six Ecuadorian streams covering a gradient in four different stability measures and other stream characteristics. The physical variables current velocity, water depth, horizontal...... of families vs. individuals) were related to the physical characteristics of individual stone habitats. My second objective was to quantify temporal variability in fauna-stone relationships and to analyse if such variability was related to overall stability of stream reaches. Partial Least Squares (PLS...

  20. Biological Diversity, Ecological Health and Condition of Aquatic Assemblages at National Wildlife Refuges in Southern Indiana, USA

    Directory of Open Access Journals (Sweden)

    Thomas Simon

    2015-01-01

    Full Text Available The National Wildlife Refuge system is a vital resource for the protection and conservation of biodiversity and biological integrity in the United States. Surveys were conducted to determine the spatial and temporal patterns of fish, macroinvertebrate, and crayfish populations in two watersheds that encompass three refuges in southern Indiana. The Patoka River National Wildlife Refuge had the highest number of aquatic species with 355 macroinvertebrate taxa, six crayfish species, and 82 fish species, while the Big Oaks National Wildlife Refuge had 163 macroinvertebrate taxa, seven crayfish species, and 37 fish species. The Muscatatuck National Wildlife Refuge had the lowest diversity of macroinvertebrates with 96 taxa and six crayfish species, while possessing the second highest fish species richness with 51 species. Habitat quality was highest in the Muscatatuck River drainage with increased amounts of forested habitats compared to the Patoka River drainage. Biological integrity of the three refuges ranked the Patoka NWR as the lowest biological integrity (mean IBI reach scores = 35 IBI points, while Big Oaks had the highest biological integrity (mean IBI reach score = 41 IBI points. The Muscatatuck NWR had a mean IBI reach score of 31 during June, which seasonally increased to a mean of 40 IBI points during summer. Watershed IBI scores and habitat condition were highest in the Big Oaks NWR.

  1. Biological Diversity, Ecological Health and Condition of Aquatic Assemblages at National Wildlife Refuges in Southern Indiana, USA

    Science.gov (United States)

    Morris, Charles C.; Robb, Joseph R.; McCoy, William

    2015-01-01

    Abstract The National Wildlife Refuge system is a vital resource for the protection and conservation of biodiversity and biological integrity in the United States. Surveys were conducted to determine the spatial and temporal patterns of fish, macroinvertebrate, and crayfish populations in two watersheds that encompass three refuges in southern Indiana. The Patoka River National Wildlife Refuge had the highest number of aquatic species with 355 macroinvertebrate taxa, six crayfish species, and 82 fish species, while the Big Oaks National Wildlife Refuge had 163 macroinvertebrate taxa, seven crayfish species, and 37 fish species. The Muscatatuck National Wildlife Refuge had the lowest diversity of macroinvertebrates with 96 taxa and six crayfish species, while possessing the second highest fish species richness with 51 species. Habitat quality was highest in the Muscatatuck River drainage with increased amounts of forested habitats compared to the Patoka River drainage. Biological integrity of the three refuges ranked the Patoka NWR as the lowest biological integrity (mean IBI reach scores = 35 IBI points), while Big Oaks had the highest biological integrity (mean IBI reach score = 41 IBI points). The Muscatatuck NWR had a mean IBI reach score of 31 during June, which seasonally increased to a mean of 40 IBI points during summer. Watershed IBI scores and habitat condition were highest in the Big Oaks NWR. PMID:25632261

  2. Macroinvertebrate community response to acid mine drainage in rivers of the High Andes (Bolivia).

    NARCIS (Netherlands)

    Damme, P.A. van; Hamel, C.; Ayala, A.; Bervoets, L.

    2008-01-01

    Several High Andes Rivers are characterized by inorganic water pollution known as acid mine drainage (AMD). The aim of this study was to assess the relationship between metal concentrations in the sediments and the macroinvertebrate communities in two river basins affected by AMD. In general, the

  3. A study of post-thermal recovery of the macroinvertebrate community of Four Mile Creek, June 1985--September 1987. [Savannah River Plant

    Energy Technology Data Exchange (ETDEWEB)

    Lauritsen, D.; Starkel, W.; Specht, W.

    1989-11-01

    Four Mile Creek is one of several streams at the Savannah River Site which has received thermal effluents ({le}70{degrees}C water) from nuclear production operations. From 1955--mid-1985, Four Mile Creek received thermal effluent from C-Reactor as well as non-thermal discharges from F and H Separation Areas. Total discharges from all of these facilities was about ten times higher than the natural flow of the creek (Firth et al. 1986). All water being discharged into Four Mile Creek was originally pumped from the Savannah River. This study reports the results of the artificial substrate sampling of macroinvertebrate communities of Four Mile Creek from June 1985 through September 1987, when sampling was terminated. Macroinvertebrate taxa richness, densities, and biomass data from this study are compared to Four Mile data collected prior to the shutdown of C-Reactor (Kondratieff and Kondratieff 1985 and Firth et al. 1986), and to comparable macroinvertebrate data from other Savannah River Site streams. 29 refs., 11 figs., 4 tabs.

  4. 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

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

    NARCIS (Netherlands)

    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

  6. Macro-Invertebrate Decline in Surface Water Polluted with Imidacloprid : A Rebuttal and Some New Analyses

    NARCIS (Netherlands)

    Vijver, M.G.; Brink, van den P.J.

    2014-01-01

    Imidacloprid, the largest selling insecticide in the world, has received particular attention from scientists, policymakers and industries due to its potential toxicity to bees and aquatic organisms. The decline of aquatic macro-invertebrates due to imidacloprid concentrations in the Dutch surface

  7. Macro-Invertebrate Decline in surface water polluted with Imidacloprid: A rebuttal and soome new analyses

    NARCIS (Netherlands)

    Vijver, M.G.; Brink, van den P.J.

    2014-01-01

    Imidacloprid, the largest selling insecticide in the world, has received particular attention from scientists, policymakers and industries due to its potential toxicity to bees and aquatic organisms. The decline of aquatic macro-invertebrates due to imidacloprid concentrations in the Dutch surface

  8. Contribution of trace metals in structuring in situ macroinvertebrate community composition along a salinity gradient

    NARCIS (Netherlands)

    Peeters, E.T.H.M.; Gardeniers, J.J.P.; Koelmans, A.A.

    2000-01-01

    Macroinvertebrates were studied along a salinity gradient in the North Sea Canal, The Netherlands, to quantify the effect of trace metals (cadmium, copper, lead, zinc) on community composition. In addition, two methods for assessing metal bioavailability (normalizing metal concentrations on organic

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

    International Nuclear Information System (INIS)

    Rutherford, L.G.; Cherry, D.S.; Dobbs, M.G.; Cairns, J. Jr.; Zipper, C.E.

    1995-01-01

    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

  10. Homestead fish farmers' production profile in Osun state, Nigeria ...

    African Journals Online (AJOL)

    Homestead fish farming in the Nigeria is carried out by small scale operators in small fresh water ponds. ... fish farmers in Osun state is also characterized by a high level of use of improved fish farming techniques and improved technologies.

  11. 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.

  12. Stream macroinvertebrate communities across a gradient of natural gas development in the Fayetteville Shale.

    Science.gov (United States)

    Johnson, Erica; Austin, Bradley J; Inlander, Ethan; Gallipeau, Cory; Evans-White, Michelle A; Entrekin, Sally

    2015-10-15

    Oil and gas extraction in shale plays expanded rapidly in the U.S. and is projected to expand globally in the coming decades. Arkansas has doubled the number of gas wells in the state since 2005 mostly by extracting gas from the Fayetteville Shale with activity concentrated in mixed pasture-deciduous forests. Concentrated well pads in close proximity to streams could have adverse effects on stream water quality and biota if sedimentation associated with developing infrastructure or contamination from fracturing fluid and waste occurs. Cumulative effects of gas activity and local habitat conditions on macroinvertebrate communities were investigated across a gradient of gas well activity (0.2-3.6 wells per km(2)) in ten stream catchments in spring 2010 and 2011. In 2010, macroinvertebrate density was positively related to well pad inverse flowpath distance from streams (r=0.84, pgas activity close to streams. However, stream water turbidity (r=0.69, p=0.02) and chlorophyll a (r=0.89, pgas well activities. In 2011, a year with record spring flooding, a different pattern emerged where mayfly density (p=0.74, p=0.01) and mayfly, stonefly, and caddisfly richness (r=0.78, p=0.008) increased in streams with greater well density and less silt cover. Hydrology and well pad placement in a catchment may interact to result in different relationships between biota and catchment activity between the two sample years. Our data show evidence of different macroinvertebrate communities expressed in catchments with different levels of gas activity that reinforce the need for more quantitative analyses of cumulative freshwater-effects from oil and gas development. Copyright © 2015 Elsevier B.V. All rights reserved.

  13. Aquatic insects as the main food resource of fish the community in a Neotropical reservoir

    Directory of Open Access Journals (Sweden)

    Ana Paula Vidotto-Magnoni

    Full Text Available We evaluated the feeding of fish species of the Nova Avanhandava Reservoir, low Tietê River, São Paulo State, Brazil. Fishes were collected in two stretches of the reservoir: Santa Bárbara (14 samples and Bonito (two samples between September 2002 and March 2004, using gill and seining nets. The results of stomach contents analysis were expressed with the frequency of occurrence and gravimetric method, combined in the Alimentary Index (AI. The 20 species studied consumed 52 food items, grouped in 10 food categories: aquatic insects, terrestrial insects, crustaceans, fish, macroinvertebrates, microcrustaceans, algae, vegetal matter, detritus/sediment and scales. The aquatic insects (mainly Chironomidae, Odonata and Ephemeroptera were the most common food resources, consumed by 18 species. The diet composition of the community (species grouped indicated that the dominant food category in the diet of fishes was aquatic insects (AI = 77.6%, followed by crustaceans (AI = 7.1%. Four trophic guilds were identified according a cluster analysis (Pearson distance: insectivorous (10 species, omnivorous (4 species, detritivorous (3 species and piscivorous/carcinophagous (3 species. Despite the highest number of species, the insectivorous guild was responsible for more than 80% in captures in number and biomass (CPUEn and CPUEb. The low values of niche breadth presented by all species, along with the low values of diet overlap between species pairs indicate a high degree of food resources partitioning among species. The aquatic insects, despite being the main food resource of insectivorous fishes, also complemented the diet of other species, which demonstrate the importance of this food resource for the fish community, sustaining a high diversity, abundance and biomass of fishes.

  14. Habitat degradation and fishing effects on the size structure of coral reef fish communities.

    Science.gov (United States)

    Wilson, S K; Fisher, R; Pratchett, M S; Graham, N A J; Dulvy, N K; Turner, R A; Cakacaka, A; Polunin, N V C

    2010-03-01

    Overfishing and habitat degradation through climate change pose the greatest threats to sustainability of marine resources on coral reefs. We examined how changes in fishing pressure and benthic habitat composition influenced the size spectra of island-scale reef fish communities in Lau, Fiji. Between 2000 and 2006 fishing pressure declined in the Lau Islands due to declining human populations and reduced demand for fresh fish. At the same time, coral cover declined and fine-scale architectural complexity eroded due to coral bleaching and outbreaks of crown-of-thorns starfish, Acanthaster planci. We examined the size distribution of reef fish communities using size spectra analysis, the linearized relationship between abundance and body size class. Spatial variation in fishing pressure accounted for 31% of the variation in the slope of the size spectra in 2000, higher fishing pressure being associated with a steeper slope, which is indicative of fewer large-bodied fish and/or more small-bodied fish. Conversely, in 2006 spatial variation in habitat explained 53% of the variation in the size spectra slopes, and the relationship with fishing pressure was much weaker (approximately 12% of variation) than in 2000. Reduced cover of corals and lower structural complexity was associated with less steep size spectra slopes, primarily due to reduced abundance of fish < 20 cm. Habitat degradation will compound effects of fishing on coral reefs as increased fishing reduces large-bodied target species, while habitat loss results in fewer small-bodied juveniles and prey that replenish stocks and provide dietary resources for predatory target species. Effective management of reef resources therefore depends on both reducing fishing pressure and maintaining processes that encourage rapid recovery of coral habitat.

  15. Recombinant fish parvalbumins: Candidates for diagnosis and treatment of fish allergy.

    Science.gov (United States)

    Swoboda, Ines; Bugajska-Schretter, A; Valenta, R; Spitzauer, S

    2002-01-01

    Fish and fish products represent one of the most important causes of IgE-mediated food hypersensitivity. In sensitized individuals contact with and consumption of fish can lead to severe health problems, ranging from urticaria and dermatitis to angiedema, diarrhoea, asthma and, at worst, systemic anaphylactic reactions and death. Parvalbumin, a small calcium-binding protein present in the muscles of vertebrates, was identified as the major fish allergen. We describe the isolation and characterization of cDNA clones coding for carp parvalbumin by IgE immunoscreening of a carp muscle expression library. These clones will be the basis for the production of recombinant carp parvalbumin, a useful tool for in vitro and in vivo diagnosis of fish allergy.

  16. Using macroinvertebrate assemblages and multiple stressors to infer urban stream system condition: A case study in the central US

    Science.gov (United States)

    Nichols, John W.; Hubbart, Jason A.; Poulton, Barry C.

    2016-01-01

    Characterizing the impacts of hydrologic alterations, pollutants, and habitat degradation on macroinvertebrate species assemblages is of critical value for managers wishing to categorize stream ecosystem condition. A combination of approaches including trait-based metrics and traditional bioassessments provides greater information, particularly in anthropogenic stream ecosystems where traditional approaches can be confounded by variously interacting land use impacts. Macroinvertebrates were collected from two rural and three urban nested study sites in central Missouri, USA during the spring and fall seasons of 2011. Land use responses of conventional taxonomic and trait-based metrics were compared to streamflow indices, physical habitat metrics, and water quality indices. Results show that biotic index was significantly different (p habitats in urban reaches contained 21 % more (p = 0.03) multivoltine organisms, which was positively correlated to the magnitude of peak flows (r2 = 0.91, p = 0.012) suggesting that high flow events may serve as a disturbance in those areas. Results support the use of macroinvertebrate assemblages and multiple stressors to characterize urban stream system condition and highlight the need to better understand the complex interactions of trait-based metrics and anthropogenic aquatic ecosystem stressors.

  17. Distribution of macroinvertebrates on intertidal rocky shores in Gorgona Island, Colombia (Tropical Eastern Pacific

    Directory of Open Access Journals (Sweden)

    Edgardo Londoño-Cruz

    2014-02-01

    Full Text Available Organisms found on rocky shores must endure harsh environmental conditions during tidal changes but scientific studies on tropical rocky shores are scarce, particularly in Colombian shores. Here we describe the spatial distribution of macroinvertebrates associated to the intertidal rocky ecosystems of Gorgona Island, Colombia (Tropical Eastern Pacific. Sampling was carried out in four localities around the Island: La Ventana and La Camaronera (sampled during October 2010 and La Mancora and El Muelle (sampled during March 2011. Two methodologies were used: rapid ecological assessments for qualitative data and quadrats for quantitative data. The richness, abundance, diversity (Shannon-Wiener H’, and evenness (Pielou J’ of macroinvertebrates were determined for and compared between, using one way ANOVA, each locality and the three intertidal zones of La Ventana (see methods. One hundred twenty-one species of macroinvertebrates were found during the sampling period. In all localities, Mollusca was the richest and most abundant taxon (46% of the species and 59% of the individuals, followed by Crustacea (32% of the species and 33% of the individuals. The other groups accounted for the remaining 22% of the richness and 8% of the abundance. Several studies have demonstrated that mollusks and crustaceans are the richest and most abundant taxa in marine benthic communities. Most of the abundant species found were herbivores. The species composition varied among zones. The results of dominant species for each zone are consistent with the ones observed in other tropical rocky intertidal shores. All response variables showed a decreasing pattern from the low to the high intertidal (in La Ventana. Post-hoc results indicated that the high intertidal, the zone with the harshest environmental conditions, had significantly lower values than the other two zones for all response variables. Comparisons between the low intertidal zones of the different localities

  18. 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

  19. Experimental investigation of fish downstream passage and turbine related fish mortality at an innovative hydro power setup

    International Nuclear Information System (INIS)

    Geiger, Franz; Cuchet, Mathilde; Rutschmann, Peter

    2016-01-01

    The fish downstream passage of small fish at the innovative TUM hydro shaft power plant concept was investigated experimentally. The behavior of 1974 inserted individuals of brown trout, grayling, barbel, minnow and bullhead of 45 mm to 220 mm body length was observed in a fully functional test setup which included a 35 kW Kaplan turbine and a horizontal screen with 20 mm bar clearance. The 24 h tests were conducted under nature like conditions whereas the laboratory environment also enabled targeted hydraulic situations and modifications of the bypass during the test series. A recapture rate of the fish of 99% and a subsequent 96 h observation period yielded detailed information about the migration behavior and instant as well as long term mortality. The results reveal the actual passage distribution of small fish between bypass and turbine and the turbine related injury and mortality rates in dependency of fish species, fish length, turbine discharge and bypass arrangement. General trends as well as species specific particularities could be deduced. The work confirms the suitability of the employed experimental approach and the ecological potential of the investigated hydro power plant concept. The behavioral barrier effect of the screen on small fish and the necessary of appropriate downstream migration corridor were proved and quantified. (authors)

  20. Experimental acidification of two biogeochemically-distinct neotropical streams: Buffering mechanisms and macroinvertebrate drift

    Energy Technology Data Exchange (ETDEWEB)

    Ardón, Marcelo, E-mail: ardonsayaom@ecu.edu [Department of Biology and North Carolina Center for Biodiversity, East Carolina University, Greenville, NC 27858 (United States); Duff, John H. [U.S. Geological Survey, Menlo Park, CA 94025 (United States); Ramírez, Alonso [Department of Environmental Sciences, University of Puerto Rico, San Juan, PR 00931 (Puerto Rico); Small, Gaston E. [Department of Ecology, Evolution, and Behavior, University of Minnesota, St. Paul, MN 55108 (United States); Jackman, Alan P. [University of California, Davis, CA 95616 (United States); Triska, Frank J. [U.S. Geological Survey, Menlo Park, CA 94025 (United States); Pringle, Catherine M. [Odum School of Ecology, University of Georgia, Athens, GA 30602 (United States)

    2013-01-15

    Research into the buffering mechanisms and ecological consequences of acidification in tropical streams is lacking. We have documented seasonal and episodic acidification events in streams draining La Selva Biological Station, Costa Rica. Across this forested landscape, the severity in seasonal and episodic acidification events varies due to interbasin groundwater flow (IGF). Streams that receive IGF have higher concentrations of solutes and more stable pH (∼ 6) than streams that do not receive IGF (pH ∼ 5). To examine the buffering capacity and vulnerability of macroinvertebrates to short-term acidification events, we added hydrochloric acid to acidify a low-solute, poorly buffered (without IGF) and a high-solute, well buffered stream (with IGF). We hypothesized that: 1) protonation of bicarbonate (HCO{sub 3}{sup −}) would neutralize most of the acid added in the high-solute stream, while base cation release from the sediments would be the most important buffering mechanism in the low-solute stream; 2) pH declines would mobilize inorganic aluminum (Ali) from sediments in both streams; and 3) pH declines would increase macroinvertebrate drift in both streams. We found that the high-solute stream neutralized 745 μeq/L (96% of the acid added), while the solute poor stream only neutralized 27.4 μeq/L (40%). Protonation of HCO{sub 3}{sup −} was an important buffering mechanism in both streams. Base cation, Fe{sup 2+}, and Ali release from sediments and protonation of organic acids also provided buffering in the low-solute stream. We measured low concentrations of Ali release in both streams (2-9 μeq/L) in response to acidification, but the low-solute stream released double the amount Ali per 100 μeq of acid added than the high solute stream. Macroinvertebrate drift increased in both streams in response to acidification and was dominated by Ephemeroptera and Chironomidae. Our results elucidate the different buffering mechanisms in tropical streams and

  1. Results of investigating the macroinvertebrate community of the Danube River on the sector upstream from the Iron Gate (km 1083-1071

    Directory of Open Access Journals (Sweden)

    Paunović Momir M.

    2005-01-01

    Full Text Available The present work cites results of investigating aquatic macroinvertebrates of the Danube River on the sector upstream from the Iron Gate (KM 1083-1071. The investigated part is interesting from the hydrobiological standpoint above all due to differences of faunal composition in relation to higher sections that could be expected in view of differences in overall characteristics of the river. A rich macroinvertebrate community (84 taxa was observed. The diversity of taxa is primarily a result of habitat diversity within the given stretch. Oligochaeta and Mollusca were the principal components.

  2. The effects of tertiary treated municipal wastewater on fish communities of a small river tributary in Southern Ontario, Canada

    International Nuclear Information System (INIS)

    Brown, Carolyn J.M.; Knight, Brendan W.; McMaster, Mark E.; Munkittrick, Kelly R.; Oakes, Ken D.; Tetreault, Grald R.; Servos, Mark R.

    2011-01-01

    Fish community changes associated with a tertiary treated municipal wastewater effluent outfall in the Speed River, Ontario, Canada, were evaluated at nine sites over two seasons (2008) using standardized electrofishing. Habitat evaluations were conducted to ensure that the riffle sites selected were physically similar. The fish community was dominated by several species of darters that differed in their response to the effluent outfall. There was a significant decrease in Greenside Darter (Etheostoma blennioides) but an increase in Rainbow Darter (E. caeruleum) abundance directly downstream of the outfall. Stable isotope signatures (δ 13 C and δ 15 N), which indicate shifts in energy utilization and flow, increased in Rainbow Darter downstream, but showed no change in Greenside Darter. Rainbow Darter may be exploiting a food source that is not as available at upstream sites giving them a competitive advantage over the Greenside Darter immediately downstream of the outfall. - Highlights: → Fish communities are altered by tertiary treated municipal wastewater exposure. → Relative abundance of the two dominant fish (darter) species changed downstream. → Differing stable isotope signatures in fish suggests shifting energy flow and diet. → The altered environment may allow resilient species a competitive advantage. → The system recovers quickly downstream. - Tertiary treated effluent altered fish community composition in a small receiving stream possibly as a result of altered availability of resources (diet) as indicated by stable isotopes.

  3. Environmental stressors as a driver of the trait composition of benthic macroinvertebrate assemblages in polluted Iberian rivers.

    Science.gov (United States)

    Kuzmanovic, Maja; Dolédec, Sylvain; de Castro-Catala, Nuria; Ginebreda, Antoni; Sabater, Sergi; Muñoz, Isabel; Barceló, Damià

    2017-07-01

    We used the trait composition of macroinvertebrate communities to identify the effects of pesticides and multiple stressors associated with urban land use at different sites of four rivers in Spain. Several physical and chemical stressors (high metal pollution, nutrients, elevated temperature and flow alterations) affected the urban sites. The occurrence of multiple stressors influenced aquatic assemblages at 50% of the sites. We hypothesized that the trait composition of macroinvertebrate assemblages would reflect the strategies that the assemblages used to cope with the respective environmental stressors. We used RLQ and fourth corner analysis to address the relationship between stressors and the trait composition of benthic macroinvertebrates. We found a statistically significant relationship between the trait composition and the exposure of assemblages to environmental stressors. The first RLQ dimension, which explained most of the variability, clearly separated sites according to the stressors. Urban-related stressors selected taxa that were mainly plurivoltine and fed on deposits. In contrast, pesticide impacted sites selected taxa with high levels of egg protection (better egg survival), indicating a potentially higher risk for egg mortality. Moreover, the trait diversity of assemblages at urban sites was low compared to that observed in pesticide impacted sites, suggesting the homogenization of assemblages in urban areas. Copyright © 2017 The Authors. Published by Elsevier Inc. All rights reserved.

  4. 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

  5. Vaccination in Fish

    DEFF Research Database (Denmark)

    Chettri, Jiwan Kumar

    vaccines have reduced the need for usage of antibiotics with more than 99 % since the 1980s. Fish can be vaccinated by three different administration routes: injection, immersion and oral vaccination. Injection vaccination (intraperitoneal injection of vaccine) is the most time consuming and labor...... intensive method, which however, provides the best protection of the fish. Immersion vaccination is used for immunization of a high number of small fish is cost-efficient and fast (30 sec immersion into vaccine). Oral vaccination (vaccine in feed) is the least efficient. As in higher vertebrates fish...... respond to vaccination by increasing the specific antibody titer and by activating the cellular responses. My talk will cover vaccination methods in fish, immune responses and some adverse effect of oil-adjuvanted vaccines in fish with reference to our work in rainbow trout, Oncorhynchus mykiss....

  6. 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

  7. Of Fish and Micrornas

    DEFF Research Database (Denmark)

    Bela-Ong, Dennis; Schyth, Brian Dall; Lorenzen, Niels

    Fish is an important small vertebrate multidisciplinary model for investigating various aspects of reproduction, development, disease (immunology, toxicology, carcinogenesis), and aging. It is also an important model for comparative and evolutionary studies because it represents the lower...... to the mechanisms of control of gene expression, impacting a broad range of biological processes. Thus far, >25, 000 miRNA sequences have been identified in 193 species, including fish. In fish, the interest on miRNAs started with the analysis of their expression and function during embryonic development. In our...... selection markers to identify disease-resistant fish....

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

    International Nuclear Information System (INIS)

    Soucek, D.J.; Currie, R.J.; Cherry, D.S.; Latimer, H.A.

    1998-01-01

    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

  9. scale fish- eries: a comparison of two fishing settlements in ...

    African Journals Online (AJOL)

    is widely recognised as having a major influence on marine ecosystems ... sanal and small - scale fisheries can be difficult due to geographi- ... ever - growing coastal populations, the number of small - scale ... northern Madagascar near the city of Antsiranana, ... increasingly becoming a tourist destination, and some fish-.

  10. The Distribution of Capture Fisheries Based Small Pelagic - Mackerel Fish Species In Balikpapan Waters, East Kalimantan

    Directory of Open Access Journals (Sweden)

    Said Abdusysyahid

    2014-04-01

    Full Text Available Normal 0 false false false IN X-NONE X-NONE In the utilization of common property resource, long term balance in aquaculture is difficult to maintain as people trying to maximize their profit leading to considerable extensification. The objective of this research was to analyze the number of stock, production, and effort of Mackerel fish (Scomberomorus commersonii resource based on bio-economic approach. Primary data was collected based on purposive sampling method where the respondents in this research were Small Pelagic fishers which determined deliberately due to specific consideration. Secondary data used in this research was obtained from several sources. Data production and effort (input or effort was arranged in a time sequence according to the type of fishing gears and their targets of fishery resource being studied and then determined the value of CPUE (catch per unit effort. Mathematically, the input gear to be standardized is calculated from fishing power index multiplies with input (effort of standardized gear. The result shows that the renewable capacity begins to decrease leading to a condition of biologically over fishing. Aside from that, the Mackerel fish resource in this area also experiences economically over fishing condition which indicated by higher economic calculation value and lower capture yield. /* Style Definitions */ table.MsoNormalTable {mso-style-name:"Table Normal"; mso-tstyle-rowband-size:0; mso-tstyle-colband-size:0; mso-style-noshow:yes; mso-style-priority:99; mso-style-qformat:yes; mso-style-parent:""; mso-padding-alt:0cm 5.4pt 0cm 5.4pt; mso-para-margin:0cm; mso-para-margin-bottom:.0001pt; mso-pagination:widow-orphan; font-size:11.0pt; font-family:"Calibri","sans-serif"; mso-ascii-font-family:Calibri; mso-ascii-theme-font:minor-latin; mso-fareast-font-family:"Times New Roman"; mso-fareast-theme-font:minor-fareast; mso-hansi-font-family:Calibri; mso-hansi-theme-font:minor-latin; mso-bidi-font-family:"Times New

  11. Analysis of Environmental Issues Related to Small-Scale Hydroelectric Development IV: Fish Mortality Resulting From Turbine Passage

    Energy Technology Data Exchange (ETDEWEB)

    Turbak, Susan C. [Oak Ridge National Lab. (ORNL), Oak Ridge, TN (United States); Reichle, Donna R. [Oak Ridge National Lab. (ORNL), Oak Ridge, TN (United States); Shriner, Carole R. [Oak Ridge National Lab. (ORNL), Oak Ridge, TN (United States)

    1981-01-01

    The purpose of this report is to provide summary information for use by potential developers and regulators of small-scale hydroelectric projects (defined as existing dams that can be retrofitted to a total site capacity of ≤30 MW), where turbine-related mortality of fish is a potential issue affecting site-specific development. Mitigation techniques for turbine-related mortality are not covered in this report.

  12. The macroinvertebrates of Magela Creek, Northern Territory

    International Nuclear Information System (INIS)

    Marchant, R.

    1982-04-01

    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

  13. Macroinvertebrate Richness Importance in Coastal Tropical Streams of Esmeraldas (Ecuador and Its Use and Implications in Environmental Management Procedures

    Directory of Open Access Journals (Sweden)

    Carlos Martínez-Sanz

    2014-01-01

    Full Text Available This study was aimed at determining the performance of some indices and community attributes frequently used to assess river quality and test the role of macroinvertebrate taxa richness as element of bioindication in several coastal tropical streams of western Esmeraldas (Ecuador. In addition, a macroinvertebrate taxon list of this region was provided for the first time. Thirteen sampled points distributed across nine streams were selected for this study and nineteen parameters and attributes of bioindication were tested. The differences between nonimpact and impact places were evaluated mainly using one-way analysis of variance. Jackknife 2 and Clench were used to estimate the regional richness and the quality of the inventory, respectively. Seventy taxa (principally genus and family of the main groups of macroinvertebrates were collected. Measured richness and family richness were the best metric followed by Biological Monitoring Working Party/Colombia (BMWP/Col, Odonata richness, Shannon-Weiner, and EPT richness (Ephemeroptera + Plecoptera + Trichoptera indices. Only a slight right trend (Ephemeroptera, Trichoptera, and Chironomidae attributes or incorrect performances (Average Score Per Taxon (ASPT and % EPT were showed by frequently used metrics. Finally, several recommendations were made about taxonomic level used, the ranks of quality of taxa richness, and the effort-results relationship in the field of bioindication.

  14. Responses of macroinvertebrate community metrics to a wastewater discharge in the Upper Blue River of Kansas and Missouri, USA

    Science.gov (United States)

    Poulton, Barry C.; Graham, Jennifer L.; Rasmussen, Teresa J.; Stone, Mandy L.

    2015-01-01

    The Blue River Main wastewater treatment facility (WWTF) discharges into the upper Blue River (725 km2), and is recently upgraded to implement biological nutrient removal. We measured biotic condition upstream and downstream of the discharge utilizing the macroinvertebrate protocol developed for Kansas streams. We examined responses of 34 metrics to determine the best indicators for discriminating site differences and for predicting biological condition. Significant differences between sites upstream and downstream of the discharge were identified for 15 metrics in April and 12 metrics in August. Upstream biotic condition scores were significantly greater than scores at both downstream sites in April (p = 0.02), and in August the most downstream site was classified as non-biologically supporting. Thirteen EPT taxa (Ephemeroptera, Plecoptera, Trichoptera) considered intolerant of degraded stream quality were absent at one or both downstream sites. Increases in tolerance metrics and filtering macroinvertebrates, and a decline in ratio of scrapers to filterers all indicated effects of increased nutrient enrichment. Stepwise regressions identified several significant models containing a suite of metrics with low redundancy (R2 = 0.90 - 0.99). Based on the rapid decline in biological condition downstream of the discharge, the level of nutrient removal resulting from the facility upgrade (10% - 20%) was not enough to mitigate negative effects on macroinvertebrate communities.

  15. Do laboratory salinity tolerances of freshwater animals correspond with their field salinity?

    Energy Technology Data Exchange (ETDEWEB)

    Kefford, Ben J.; Papas, Phil J.; Metzeling, Leon; Nugegoda, Dayanthi

    2004-06-01

    The degree to which laboratory derived measures of salinity tolerance reflect the field distributions of freshwater biota is uncertain. In this paper we compare laboratory-derived acute salinity tolerance (LC{sub 50} values) of freshwater macroinvertebrates (range 5.5-76 mS/cm) and fish (range 2.7-82 mS/cm) from southeastern Australia with the salinity from which they have been collected in the field. Only 4% of the macroinvertebrates were collected at salinity levels substantially higher than their 72-h LC{sub 50} obtained from directly transferring animals from low salinity water to the water they were tested (direct transfer LC{sub 50}). This LC{sub 50} value was correlated with the maximum salinity at which a species had been collected. For common macroinvertebrates, the maximum field salinity was approximated by the direct transfer 72-h LC{sub 50}. For adult freshwater fish, 21% of species were collected at salinities substantially greater than their acute direct transfer LC{sub 50} and there was a weak relationship between these two variables. Although there was a weak correlation between the direct transfer LC{sub 50} of early life stages of freshwater fish and the maximum field salinity, 58% of the field distribution were in higher than their LC{sub 50} values. In contrast, LC{sub 50} determined from experiments that acclimated adult fish to higher salinity (slow acclimation) provided a better indication of the field distribution: with only one fish species (7%) being in conflict with their maximum field salinity and a strong positive relationship between these variables. This study shows that laboratory measures of acute salinity tolerance can reflect the maximum salinity that macroinvertebrate and fish species inhabit and are consistent with some anecdotal observations from other studies. - Acute laboratory salinity tolerances relate to maximum salinity where organisms occur in nature.

  16. Do laboratory salinity tolerances of freshwater animals correspond with their field salinity?

    International Nuclear Information System (INIS)

    Kefford, Ben J.; Papas, Phil J.; Metzeling, Leon; Nugegoda, Dayanthi

    2004-01-01

    The degree to which laboratory derived measures of salinity tolerance reflect the field distributions of freshwater biota is uncertain. In this paper we compare laboratory-derived acute salinity tolerance (LC 50 values) of freshwater macroinvertebrates (range 5.5-76 mS/cm) and fish (range 2.7-82 mS/cm) from southeastern Australia with the salinity from which they have been collected in the field. Only 4% of the macroinvertebrates were collected at salinity levels substantially higher than their 72-h LC 50 obtained from directly transferring animals from low salinity water to the water they were tested (direct transfer LC 50 ). This LC 50 value was correlated with the maximum salinity at which a species had been collected. For common macroinvertebrates, the maximum field salinity was approximated by the direct transfer 72-h LC 50 . For adult freshwater fish, 21% of species were collected at salinities substantially greater than their acute direct transfer LC 50 and there was a weak relationship between these two variables. Although there was a weak correlation between the direct transfer LC 50 of early life stages of freshwater fish and the maximum field salinity, 58% of the field distribution were in higher than their LC 50 values. In contrast, LC 50 determined from experiments that acclimated adult fish to higher salinity (slow acclimation) provided a better indication of the field distribution: with only one fish species (7%) being in conflict with their maximum field salinity and a strong positive relationship between these variables. This study shows that laboratory measures of acute salinity tolerance can reflect the maximum salinity that macroinvertebrate and fish species inhabit and are consistent with some anecdotal observations from other studies. - Acute laboratory salinity tolerances relate to maximum salinity where organisms occur in nature

  17. Multi-scale functional and taxonomic β-diversity of the macroinvertebrate communities in a Mediterranean coastal lagoon

    Directory of Open Access Journals (Sweden)

    D. CABANA

    2017-03-01

    Full Text Available Benthic macroinvertebrate communities form the basis of the intricate lagoonal food web. Understanding their functional and taxonomic response, from a β-diversity perspective, is essential to disclose underlying patterns with potential applicability in conservation and management actions. Within the central lagoon of Messolonghi we studied the main environmental components structuring the macroinvertebrate community. We analyzed the β-taxonomic and β-functional diversity across the main habitats and seasons, over a year time frame. Our results outline habitat type and vegetation biomass as the major factors structuring the communities. We found environmental variability to have a positive correlation with functional β-diversity, however no correlation was found with taxonomic β-diversity. Across the seasons an asynchronous response of the functional and taxonomic β-diversity was identified. The taxonomic composition displayed significant heterogeneity during the driest period and the functional during the rainy season. Across the habitats the unvegetated presented higher taxonomic homogeneity and functionally heterogeneity, contrary the vegetated habitats present higher taxonomic variability and functional homogeneity. Across the seasons and habitats a pattern of functional redundancy and taxonomic replacement was identified. Besides high functional turnover versus low taxonomic turnover was documented in an anthropogenic organically enriched habitat We conclude that habitats display independent functional and taxonomic seasonal patterns, thus different processes may contribute to their variability. The framework presented here highlights the importance of studying both β-diversity components framed in a multiscale approach to better understand ecological processes and variability patterns. These results are important to understand macroinvertebrate community assembly processes and are valuable for conservation purposes.

  18. Optimizing sealed transports of small ornamental fish

    Directory of Open Access Journals (Sweden)

    Rui Esteves da Silva

    2014-06-01

    Full Text Available This is a report on multiple simulated long-term transports of small ornamental fish inside plastic bags. The species involved were Diplodus sargus, Gobius paganellus, Gobiusculus flavescens, Lepadogaster lepadogaster and Lipophrys pholis. The objective of such simulations was moving the maximum bioload possible while ensuring 100% survivorship, ultimately resulting in savings for the end-receiver. Transports were simulated over 24, 48 and 72 hours, with increasing animal bioloads per bag. Half of the trials were performed with “regular” saltwater while the other half involved seawater buffered with Amquel ®, sodium carbonate and sodium bicarbonate, with the objective of keeping ammonia low and pH similar to initial baseline values. At the end of each trial, temperature, dissolved oxygen, pH and ammonia were analized and the survival rate calculated and recorded. L. lepadogaster endured the highest bioloads at 100% survivorship (i.e. up to 30 g / L, which is not surprising given the intertidal nature of this species. D. sargus exhibited mortalities with bioloads as low as 3,23 g / L, which echoes its predominantly pelagic nature and relatively lesser ability to endure confinement. The three remaining species showed varying degrees of tolerance to increasing bioloads in transport: L. pholis, also an intertidal species, handled up to 20 g/L over 72 hours, while G. paganellus handled up to 7 g/L over 72 hours, and G. flavescens (a predominantly pelagic species could deal with no more than 6 g/L up to 72 hours.

  19. Hankin and Reeves' Approach to Estimating Fish Abundance in Small Streams : Limitations and Potential Options.

    Energy Technology Data Exchange (ETDEWEB)

    Thompson, William L. [Bonneville Power Administration, Portland, OR (US). Environment, Fish and Wildlife

    2000-11-01

    Hankin and Reeves' (1988) approach to estimating fish abundance in small streams has been applied in stream-fish studies across North America. However, as with any method of population estimation, there are important assumptions that must be met for estimates to be minimally biased and reasonably precise. Consequently, I investigated effects of various levels of departure from these assumptions via simulation based on results from an example application in Hankin and Reeves (1988) and a spatially clustered population. Coverage of 95% confidence intervals averaged about 5% less than nominal when removal estimates equaled true numbers within sampling units, but averaged 62% - 86% less than nominal when they did not, with the exception where detection probabilities of individuals were >0.85 and constant across sampling units (95% confidence interval coverage = 90%). True total abundances averaged far (20% - 41%) below the lower confidence limit when not included within intervals, which implies large negative bias. Further, average coefficient of variation was about 1.5 times higher when removal estimates did not equal true numbers within sampling units (C{bar V} = 0.27 [SE = 0.0004]) than when they did (C{bar V} = 0.19 [SE = 0.0002]). A potential modification to Hankin and Reeves' approach is to include environmental covariates that affect detection rates of fish into the removal model or other mark-recapture model. A potential alternative is to use snorkeling in combination with line transect sampling to estimate fish densities. Regardless of the method of population estimation, a pilot study should be conducted to validate the enumeration method, which requires a known (or nearly so) population of fish to serve as a benchmark to evaluate bias and precision of population estimates.

  20. Hankin and Reeves' approach to estimating fish abundance in small streams: limitations and potential options; TOPICAL

    International Nuclear Information System (INIS)

    Thompson, William L.

    2000-01-01

    Hankin and Reeves' (1988) approach to estimating fish abundance in small streams has been applied in stream-fish studies across North America. However, as with any method of population estimation, there are important assumptions that must be met for estimates to be minimally biased and reasonably precise. Consequently, I investigated effects of various levels of departure from these assumptions via simulation based on results from an example application in Hankin and Reeves (1988) and a spatially clustered population. Coverage of 95% confidence intervals averaged about 5% less than nominal when removal estimates equaled true numbers within sampling units, but averaged 62% - 86% less than nominal when they did not, with the exception where detection probabilities of individuals were and gt;0.85 and constant across sampling units (95% confidence interval coverage= 90%). True total abundances averaged far (20% - 41%) below the lower confidence limit when not included within intervals, which implies large negative bias. Further, average coefficient of variation was about 1.5 times higher when removal estimates did not equal true numbers within sampling units (C(bar V)0.27[SE= 0.0004]) than when they did (C(bar V)= 0.19[SE= 0.0002]). A potential modification to Hankin and Reeves' approach is to include environmental covariates that affect detection rates of fish into the removal model or other mark-recapture model. A potential alternative is to use snorkeling in combination with line transect sampling to estimate fish densities. Regardless of the method of population estimation, a pilot study should be conducted to validate the enumeration method, which requires a known (or nearly so) population of fish to serve as a benchmark to evaluate bias and precision of population estimates

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

    International Nuclear Information System (INIS)

    Lagauzere, S.

    2008-06-01

    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

  2. Climate variability and change scenarios for a marine commodity: Modelling small pelagic fish, fisheries and fishmeal in a globalized market

    Science.gov (United States)

    Merino, Gorka; Barange, Manuel; Mullon, Christian

    2010-04-01

    The world's small pelagic fish populations, their fisheries, fishmeal and fish oil production industries and markets are part of a globalised production and consumption system. The potential for climate variability and change to alter the balance in this system is explored by means of bioeconomic models at two different temporal scales, with the objective of investigating the interactive nature of environmental and human-induced changes on this globalised system. Short-term (interannual) environmental impacts on fishmeal production are considered by including an annual variable production rate on individual small pelagic fish stocks over a 10-year simulation period. These impacts on the resources are perceived by the fishmeal markets, where they are confronted by two aquaculture expansion hypotheses. Long-term (2080) environmental impacts on the same stocks are estimated using long-term primary production predictions as proxies for the species' carrying capacities, rather than using variable production rates, and are confronted on the market side by two alternative fishmeal management scenarios consistent with IPCC-type storylines. The two scenarios, World Markets and Global Commons, are parameterized through classic equilibrium solutions for a global surplus production bioeconomic model, namely maximum sustainable yield and open access, respectively. The fisheries explicitly modelled in this paper represent 70% of total fishmeal production, thus encapsulating the expected dynamics of the global production and consumption system. Both short and long-term simulations suggest that the sustainability of the small pelagic resources, in the face of climate variability and change, depends more on how society responds to climate impacts than on the magnitude of climate alterations per se.

  3. Salinity as the main factor structuring small-bodied fish assemblages in hydrologically altered Mediterranean coastal lagoons

    Directory of Open Access Journals (Sweden)

    Sílvia Rodríguez-Climent

    2013-03-01

    Full Text Available In the Ebro Delta coastal lagoons, one of the main anthropogenic pressures is the artificial freshwater input. Each coastal lagoon has different water management schemes causing profound changes in its physicochemical characteristics. The main objective of this water management is to favour some bird species with interest either for conservation or hunting activities. The present study assesses the influence of hydrological alteration on the fish assemblages of three coastal lagoons in the Ebro Delta. The small-bodied fish fauna was mainly composed of five families: Gobiidae, Poecilidae, Cyprinodontidae, Atherinidae and Mugilidae. Salinity was found to be the main factor structuring fish community in the lagoons. The dominant species was the common goby (Pomatochistus microps when the lagoons reached higher salinity values, whereas the invasive eastern mosquitofish (Gambusia holbrooki dominated during the period of higher freshwater inputs. The juveniles of the family Mugilidae showed low catch per unit effort, especially during the period of lower salinity. This same pattern was found for the endangered Spanish toothcarp (Aphanius iberus. Overall, introduced species were favoured by low salinity, which highlights the importance of changing the present water management by reducing the freshwater inputs in order to maintain suitable levels of salinity to favour native species that are important for both commercial and conservation purposes.

  4. 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.

  5. Macro-invertebrate decline in surface water polluted with imidacloprid.

    Directory of Open Access Journals (Sweden)

    Tessa C Van Dijk

    Full Text Available 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 on imidacloprid concentrations in surface water in the Netherlands enabled us to test this hypothesis. Our regression analysis showed a significant negative relationship (P<0.001 between macro-invertebrate abundance and imidacloprid concentration for all species pooled. A significant negative relationship was also found for the orders Amphipoda, Basommatophora, Diptera, Ephemeroptera and Isopoda, and for several species separately. The order Odonata had a negative relationship very close to the significance threshold of 0.05 (P = 0.051. However, in accordance with previous research, a positive relationship was found for the order Actinedida. We used the monitoring field data to test whether the existing three water quality norms for imidacloprid in the Netherlands are protective in real conditions. Our data show that macrofauna abundance drops sharply between 13 and 67 ng l(-1. For aquatic ecosystem protection, two of the norms are not protective at all while the strictest norm of 13 ng l(-1 (MTR seems somewhat protective. In addition to the existing experimental evidence on the negative effects of imidacloprid on invertebrate life, our study, based on data from large-scale field monitoring during multiple years, shows that serious concern about the far-reaching consequences of the abundant use of imidacloprid for aquatic ecosystems is justified.

  6. Soil macroinvertebrate communities across a productivity gradient in deciduous forests of eastern North America

    Science.gov (United States)

    Evelyn S. Wenk; Mac A. Callaham; Joseph O' Brien; Paul J. Hanson

    2016-01-01

    Within the temperate, deciduous forests of the eastern US, diverse soil-fauna communities are structured by a combination of environmental gradients and interactions with other biota. The introduction of non-native soil taxa has altered communities and soil processes, and adds another degree of variability to these systems. We sampled soil macroinvertebrate abundance...

  7. Fishing degrades size structure of coral reef fish communities.

    Science.gov (United States)

    Robinson, James P W; Williams, Ivor D; Edwards, Andrew M; McPherson, Jana; Yeager, Lauren; Vigliola, Laurent; Brainard, Russell E; Baum, Julia K

    2017-03-01

    Fishing pressure on coral reef ecosystems has been frequently linked to reductions of large fishes and reef fish biomass. Associated impacts on overall community structure are, however, less clear. In size-structured aquatic ecosystems, fishing impacts are commonly quantified using size spectra, which describe the distribution of individual body sizes within a community. We examined the size spectra and biomass of coral reef fish communities at 38 US-affiliated Pacific islands that ranged in human presence from near pristine to human population centers. Size spectra 'steepened' steadily with increasing human population and proximity to market due to a reduction in the relative biomass of large fishes and an increase in the dominance of small fishes. Reef fish biomass was substantially lower on inhabited islands than uninhabited ones, even at inhabited islands with the lowest levels of human presence. We found that on populated islands size spectra exponents decreased (analogous to size spectra steepening) linearly with declining biomass, whereas on uninhabited islands there was no relationship. Size spectra were steeper in regions of low sea surface temperature but were insensitive to variation in other environmental and geomorphic covariates. In contrast, reef fish biomass was highly sensitive to oceanographic conditions, being influenced by both oceanic productivity and sea surface temperature. Our results suggest that community size structure may be a more robust indicator than fish biomass to increasing human presence and that size spectra are reliable indicators of exploitation impacts across regions of different fish community compositions, environmental drivers, and fisheries types. Size-based approaches that link directly to functional properties of fish communities, and are relatively insensitive to abiotic variation across biogeographic regions, offer great potential for developing our understanding of fishing impacts in coral reef ecosystems. © 2016

  8. Demersal and larval fish assemblages in the Chukchi Sea

    Science.gov (United States)

    Norcross, Brenda L.; Holladay, Brenda A.; Busby, Morgan S.; Mier, Kathryn L.

    2010-01-01

    A multidisciplinary research cruise was conducted in the Chukchi Sea in summer 2004 during which we investigated assemblages of small demersal fishes and ichthyoplankton and the water masses associated with these assemblages. This study establishes a baseline of 30 demersal fish and 25 ichthyoplankton taxa in US and Russian waters of the Chukchi Sea. Presence/absence of small demersal fish clustered into four assemblages: Coastal Fishes, Western Chukchi Fishes, South Central Chukchi Fishes, and North Central Chukchi Fishes. Habitats occupied by small demersal fishes were characterized by sediment type, bottom salinity, and bottom temperature. Abundance of ichthyoplankton grouped into three assemblages with geographical extent similar to that of the bottom assemblages, except that there was a single assemblage for Central Chukchi Fishes. Water-column temperature and salinity characterized ichthyoplankton habitats. Three water masses, Alaska Coastal Water, Bering Sea Water, and Winter Water, were identified from both bottom and depth-averaged water-column temperature and salinity. A fourth water mass, Resident Chukchi Water, was identified only in the bottom water. The water mass and habitat characteristics with which demersal and larval fish assemblages were associated create a baseline to measure anticipated effects of climate change that are expected to be most severe at high latitudes. Monitoring fish assemblages could be a tool for assessing the effects of climate change. Climate-induced changes in distributions of species would result in a restructuring of fish assemblages in the Chukchi Sea.

  9. Fish community of a small, temperate, urban river in South Africa ...

    African Journals Online (AJOL)

    Catches were comprised of indigenous freshwater, marine migrant and alien fishes. Marine migrant fishes, including catadromous species dependent on freshwater for early life-history strategies, were significantly affected by instream barriers which prohibited upstream migration of all species except Anguilla mossambica.

  10. 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 speci...

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

    Directory of Open Access Journals (Sweden)

    M. S. G. Moura e Silva

    Full Text Available Abstract 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 < 0.05 between near and distant sites, for both periods (dry and rainy seasons. The position of the samplers significantly affected the structure of 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.

  12. Scale-dependence of the correlation between human population and the species richness of stream macro-invertebrates

    DEFF Research Database (Denmark)

    Pecher, C.; Fritz, Susanne; Marini, L.

    2010-01-01

    . This is surprising as EPT are bio-indicators of stream pollution and most local studies report higher species richness of these macro-invertebrates where human influences on water quality are lower. Using a newly collated taxonomic dataset, we studied whether the species richness of EPT is related to human...

  13. Power analysis as a tool to identify statistically informative indicators for monitoring coral reef disturbances.

    Science.gov (United States)

    Van Wynsberge, Simon; Gilbert, Antoine; Guillemot, Nicolas; Heintz, Tom; Tremblay-Boyer, Laura

    2017-07-01

    Extensive biological field surveys are costly and time consuming. To optimize sampling and ensure regular monitoring on the long term, identifying informative indicators of anthropogenic disturbances is a priority. In this study, we used 1800 candidate indicators by combining metrics measured from coral, fish, and macro-invertebrate assemblages surveyed from 2006 to 2012 in the vicinity of an ongoing mining project in the Voh-Koné-Pouembout lagoon, New Caledonia. We performed a power analysis to identify a subset of indicators which would best discriminate temporal changes due to a simulated chronic anthropogenic impact. Only 4% of tested indicators were likely to detect a 10% annual decrease of values with sufficient power (>0.80). Corals generally exerted higher statistical power than macro-invertebrates and fishes because of lower natural variability and higher occurrence. For the same reasons, higher taxonomic ranks provided higher power than lower taxonomic ranks. Nevertheless, a number of families of common sedentary or sessile macro-invertebrates and fishes also performed well in detecting changes: Echinometridae, Isognomidae, Muricidae, Tridacninae, Arcidae, and Turbinidae for macro-invertebrates and Pomacentridae, Labridae, and Chaetodontidae for fishes. Interestingly, these families did not provide high power in all geomorphological strata, suggesting that the ability of indicators in detecting anthropogenic impacts was closely linked to reef geomorphology. This study provides a first operational step toward identifying statistically relevant indicators of anthropogenic disturbances in New Caledonia's coral reefs, which can be useful in similar tropical reef ecosystems where little information is available regarding the responses of ecological indicators to anthropogenic disturbances.

  14. Fishes and humankind III. Editorial.

    Directory of Open Access Journals (Sweden)

    Andrew K. G. Jones

    1999-12-01

    Full Text Available The publication of this group of three papers form part of the 1987 meeting of the International Council for Archaeozoologists Fish Remains Working Group which took place at the University of York, U. K. The papers illustrate an increased awareness of the significance of ichthyological research to archaeology and cover three areas of research: taphonomy; fishing artefacts; and fish remains recovered from an excavation. Jones sheds some light on the relative robustness of the bewildering array of elements in a fish skeleton by recording damage to a skeleton when it is trampled. His paper suggests an index of robustness which might be used to assess the degree of fragmentation in archaeological assemblages. Kemp reports on the excavation of a small medieval building located adjacent to medieval fish ponds created by Cistercian monks in North Yorkshire, England. In addition to the structural evidence, an impressive assemblage of weights, presumably net weights, found on or near the site is published. Perhaps most significant is a large lead weight which may have been used to weight catches of fish from the ponds. Fish remains recovered from two excavations at the quayside at Newcastle-upon-Tyne, England are discussed by Nicholson. Around 6000 identified bones form the basis for the study, the majority of which were identified as Gadid (cod family or herring. While the main food fishes typify fish bone assemblages from most post-Roman urban archaeological sites, the identification of small fishes such as sandeels, smelt, gobies and buttefish may indicate the utilisation of fish not nowadays considered as food at all. Given the diversity of species (30 individual species identified it is suggested that the remains from the main bone-producing organic horizons, dated to the late twelfth to thirteenth centuries, may include discard from a nearby fishmarket.

  15. 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.

  16. Mercury and selenium concentrations in biofilm, macroinvertebrates, and fish collected in the Yankee Fork of the Salmon River, Idaho, USA, and their potential effects on fish health

    Science.gov (United States)

    Rhea, Darren T.; Farag, Aïda M.; Harper, David D.; McConnell, Elizabeth; Brumbaugh, William G.

    2013-01-01

    The Yankee Fork is a large tributary of the Salmon River located in central Idaho, USA, with an extensive history of placer and dredge-mining activities. Concentrations of selenium (Se) and mercury (Hg) in various aquatic trophic levels were measured in the Yankee Fork during 2001 and 2002. Various measurements of fish health were also performed. Sites included four on the mainstem of the Yankee Fork and two off-channel sites in partially reclaimed dredge pools used as rearing habitat for cultured salmonid eggs and fry. Hg concentrations in whole mountain whitefish and shorthead sculpin ranged from 0.28 to 0.56 μg/g dry weight (dw), concentrations that are generally less than those reported to have significant impacts on fish. Biofilm and invertebrates ranged from 0.05 to 0.43 μg Hg/g dw. Se concentrations measured in biota samples from the Yankee Fork were greater than many representative samples collected in the Snake and Columbia watersheds and often exceeded literature-based toxic thresholds. Biofilm and invertebrates ranged from 0.58 to 4.66 μg Se/g dw. Whole fish ranged from 3.92 to 7.10 μg Se/g dw, and gonads ranged from 6.91 to 31.84 μg Se/g dw. Whole-body Se concentrations exceeded reported toxicological thresholds at three of four sites and concentrations in liver samples were mostly greater than concentrations shown to have negative impacts on fish health. Histological examinations performed during this study noted liver abnormalities, especially in shorthead sculpin, a bottom-dwelling species.

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

    DEFF Research Database (Denmark)

    Rasmussen, Jes

    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...

  18. LANDSCAPE INFLUENCES ON IN-STREAM BIOTIC INTEGRITY: USE OF MACROINVERTEBRATE METRICS TO IDENTIFY LANDSCAPE STRESSORS IN HEADWATER CATCHMENTS

    Science.gov (United States)

    The biotic integrity of streams is profoundly influenced by quantitative and qualitative features in the landscape of the surrounding catchment. In this study, aquatic macroinvertebrate metrics (e.g., relative abundance of Ephemeroptera, Trichoptera, and/or Plecoptera taxa, or t...

  19. Local fish extinction in a small tropical lake in Brazil

    Directory of Open Access Journals (Sweden)

    Paulo dos Santos Pompeu

    Full Text Available Lagoa Santa is a shallow permanent lake, located in Belo Horizonte metropolitan region, Brazil. In this study, the loss in fish diversity of the lake over the past 150 years is evaluated. Local extinction of almost 70% of the original fish fauna is described. Probably, the main causes of this richness loss were: obstruction of natural communication with rio das Velhas, non-native species introduction, change in the water level, organic pollution, and elimination of littoral and submerged vegetation.

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

    OpenAIRE

    Teixeira, Heliana Lilita Gonçalves

    2010-01-01

    Tese de doutoramento em Biologia (Ecologia) apresentada à Faculdade de Ciências e Tecnologia da Universidade de Coimbra 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 Eur...

  1. Aquatic macroinvertebrate diversity and composition in streams along an altitudinal gradient in Southeastern Brazil

    OpenAIRE

    Henriques-Oliveira, Ana Lucia; Nessimian, Jorge Luiz

    2010-01-01

    Aquatic macroinvertebrate diversity and composition in streams along an altitudinal gradient in Southeastern Brazil. A study concerning taxonomic richness and composition of the aquatic insect fauna in streams within the same catchment basin along an altitudinal gradient in Southeast Brazil, was conducted to test the hypothesis that there is a faunal discontinuity in the biocenotic composition, related to differences in altitude and latitude. In Southeastern Brazil, around latitude 22°, this ...

  2. Role of morphometry in determining the feeding success of small freshwater fish species: Multivariate analysis of Amblypharyngodon mola, Puntius ticto, and Esomus danricus

    Directory of Open Access Journals (Sweden)

    Nandi Sudarshana

    2015-06-01

    Full Text Available Factor and multiple regression analysis were used to extract the morphometric variables that contributed to feeding success in three small freshwater fishes. Of the first two factors, factor 1, showed high loading of gut weight (GW, length of the upper (UJ, and lower jaws (LJ in mola, Amblypharyngodon mola (Hamilton, and GW and vertical mouth opening (VMO in punti, Puntius ticto (Hamilton. In darikana, Esomus danricus (Hamilton, GW, horizontal mouth opening (HMO, and VMO were highly loaded on factor 2. Gut length (GL was closely associated withGWof all three species. Subsequently, variables with high loading on factors 1 or 2 were subjected to multiple regression analysis to observe their effect on feeding success, consideringGWas the dependent variable and the extracted variables as the independent variable. In A. mola, HMO and GL influenced GW, whereas in P. ticto, only GL determined GW in the fish. In E. danricus, GL, VMO, and HMO exerted a low effect on GW. Exceptionally, the present study suggested that feeding success in small fishes is largely determined by UJ, LJ, and GL or mouth openings.

  3. A simple non-invasive method for measuring gross brain size in small live fish with semi-transparent heads

    Directory of Open Access Journals (Sweden)

    Joacim Näslund

    2014-09-01

    Full Text Available This paper describes a non-invasive method for estimating gross brain size in small fish with semi-transparent heads, using system camera equipment. Macro-photographs were taken from above on backlit free-swimming fish undergoing light anaesthesia. From the photographs, the width of the optic tectum was measured. This measure (TeO-measure correlates well with the width of the optic tectum as measured from out-dissected brains in both brown trout fry and zebrafish (Pearson r > 0.90. The TeO-measure also correlates well with overall brain wet weight in brown trout fry (r = 0.90, but less well for zebrafish (r = 0.79. A non-invasive measure makes it possible to quickly assess brain size from a large number of individuals, as well as repeatedly measuring brain size of live individuals allowing calculation of brain growth.

  4. Healing rate and autoimmune safety of full-thickness wounds treated with fish skin acellular dermal matrix versus porcine small-intestine submucosa: a noninferiority study.

    Science.gov (United States)

    Baldursson, Baldur Tumi; Kjartansson, Hilmar; Konrádsdóttir, Fífa; Gudnason, Palmar; Sigurjonsson, Gudmundur F; Lund, Sigrún Helga

    2015-03-01

    A novel product, the fish skin acellular dermal matrix (ADM) has recently been introduced into the family of biological materials for the treatment of wounds. Hitherto, these products have been produced from the organs of livestock. A noninferiority test was used to compare the effect of fish skin ADM against porcine small-intestine submucosa extracellular matrix in the healing of 162 full-thickness 4-mm wounds on the forearm of 81 volunteers. The fish skin product was noninferior at the primary end point, healing at 28 days. Furthermore, the wounds treated with fish skin acellular matrix healed significantly faster. These results might give the fish skin ADM an advantage because of its environmental neutrality when compared with livestock-derived products. The study results on these acute full-thickness wounds might apply for diabetic foot ulcers and other chronic full-thickness wounds, and the shorter healing time for the fish skin-treated group could influence treatment decisions. To test the autoimmune reactivity of the fish skin, the participants were tested with the following ELISA (enzyme-linked immunosorbent assay) tests: RF, ANA, ENA, anti ds-DNA, ANCA, anti-CCP, and anticollagen I and II. These showed no reactivity. The results demonstrate the claims of safety and efficacy of fish skin ADM for wound care. © The Author(s) 2015.

  5. Louisiana waterthrush and benthic macroinvertebrate response to shale gas development

    Science.gov (United States)

    Wood, Petra; Frantz, Mack W.; Becker, Douglas A.

    2016-01-01

    Because shale gas development is occurring over large landscapes and consequently is affecting many headwater streams, an understanding of its effects on headwater-stream faunal communities is needed. We examined effects of shale gas development (well pads and associated infrastructure) on Louisiana waterthrush Parkesia motacilla and benthic macroinvertebrate communities in 12 West Virginia headwater streams in 2011. Streams were classed as impacted (n = 6) or unimpacted (n = 6) by shale gas development. We quantified waterthrush demography (nest success, clutch size, number of fledglings, territory density), a waterthrush Habitat Suitability Index, a Rapid Bioassessment Protocol habitat index, and benthic macroinvertebrate metrics including a genus-level stream-quality index for each stream. We compared each benthic metric between impacted and unimpacted streams with a Student's t-test that incorporated adjustments for normalizing data. Impacted streams had lower genus-level stream-quality index scores; lower overall and Ephemeroptera, Plecoptera, and Trichoptera richness; fewer intolerant taxa, more tolerant taxa, and greater density of 0–3-mm individuals (P ≤ 0.10). We then used Pearson correlation to relate waterthrush metrics to benthic metrics across the 12 streams. Territory density (no. of territories/km of stream) was greater on streams with higher genus-level stream-quality index scores; greater density of all taxa and Ephemeroptera, Plecoptera, and Trichoptera taxa; and greater biomass. Clutch size was greater on streams with higher genus-level stream-quality index scores. Nest survival analyses (n = 43 nests) completed with Program MARK suggested minimal influence of benthic metrics compared with nest stage and Habitat Suitability Index score. Although our study spanned only one season, our results suggest that shale gas development affected waterthrush and benthic communities in the headwater streams we studied. Thus, these ecological effects of

  6. Urbanization reduces and homogenizes trait diversity in stream macroinvertebrate communities.

    Science.gov (United States)

    Barnum, Thomas R; Weller, Donald E; Williams, Meghan

    2017-12-01

    More than one-half of the world's population lives in urban areas, so quantifying the effects of urbanization on ecological communities is important for understanding whether anthropogenic stressors homogenize communities across environmental and climatic gradients. We examined the relationship of impervious surface coverage (a marker of urbanization) and the structure of stream macroinvertebrate communities across the state of Maryland and within each of Maryland's three ecoregions: Coastal Plain, Piedmont, and Appalachian, which differ in stream geomorphology and community composition. We considered three levels of trait organization: individual traits, unique combinations of traits, and community metrics (functional richness, functional evenness, and functional divergence) and three levels of impervious surface coverage (low [10%]). The prevalence of an individual trait differed very little between low impervious surface and high impervious surface sites. The arrangement of trait combinations in community trait space for each ecoregion differed when impervious surface coverage was low, but the arrangement became more similar among ecoregions as impervious surface coverage increased. Furthermore, trait combinations that occurred only at low or medium impervious surface coverage were clustered in a subset of the community trait space, indicating that impervious surface affected the presence of only a subset of trait combinations. Functional richness declined with increasing impervious surface, providing evidence for environmental filtering. Community metrics that include abundance were also sensitive to increasing impervious surface coverage: functional divergence decreased while functional evenness increased. These changes demonstrate that increasing impervious surface coverage homogenizes the trait diversity of macroinvertebrate communities in streams, despite differences in initial community composition and stream geomorphology among ecoregions. Community

  7. Some aspects of the distribution and dynamics of the benthic macroinvertebrate groups from Nimăieşti valley river

    Directory of Open Access Journals (Sweden)

    CUPŞA Diana

    2005-09-01

    Full Text Available In the Nimăieşti Valley river we found in a number of four sample sites a community of benthic macroinvertebrates represented by Oligochaeta, Ephemeroptera larva, Trichoptera larva, Chironomida larva and Hidracarina species. The communities structure vary depending on season and the sampling site acording to the water quality and trophic condition of the substrate. The greatest diversity was recorded during the summer months (may-august and comparing the sample sites, we found that the first three sampling sites are very similar from the point of view of the macroinvertebrate community, but the fourth sampling site the community is different because the river pases through the town of Beiuş and as a consequence the water quality is lower that at the other three sample sites.

  8. Ecological status assessment of regulated lakes; Saeaennoesteltyjen jaervien ekologisen tilan arviointi

    Energy Technology Data Exchange (ETDEWEB)

    Keto, A.; Sutela, T.; Aroviita, J.; Tarvainen, A.; Haemaelaeinen, H.; Hellsten, S.; Vehanen, T.; Marttunen, M.

    2008-10-15

    Although regulated lakes have been studied extensively during the last 20 years in Finland, biological data are still scattered. Especially in mildly regulated lakes, data have been insufficient to determine reference conditions and to estimate ecological status as required by the Water Framework Directive. The objective of this study was to increase information about the biological quality elements in order to develop ecological classification system and to define environment objectives for regulated lakes. Both existing and new data were collected from littoral fishes, littoral macroinvertebrates and macrophytes from regulated lakes and unregulated reference lakes. New biological classification metrics were then developed and tested. Moreover, alternative combinations of the biological classification parameters were tested for assessment of ecological status of lakes. Impacts of water-level regulation were found in all three biological quality elements: the littoral fishes, macroinvertebrates and macrophytes. The ecological status of the study lakes was at its worst when winter draw-down of water-level exceeded 2-3 meters. Very sensitive species for water-level regulation were recognized in all three biological quality elements. In macrophytes these species were large isoetids, in macroinvertebrates species with at least two-year life cycle and in fishes' minnow and European bullhead. In a same lake, the status of littoral fishes, macroinvertebrates and macrophytes often differed from each other As a result, when results from different biological quality elements are combined to an overall ecological status, quite large differences can exist depending on the method used to derive the overall status; i.e., whether the most sensitive quality element (i.e. the 'one-out all-out' principle) or a median value over all quality elements is used. (orig.)

  9. Physiological and biochemical responses of small fish exposed to Athabasca oil sands sediment

    International Nuclear Information System (INIS)

    Tetrault, G.R.; Environment Canada, Burlington, ON; McMaster, M.E.; Dixon, D.G.; Parrott, J.L.

    2002-01-01

    A study was conducted to determine the influence of naturally occurring oil sands related compounds on the reproductive function and hepatic responses of fish. Wild fish, both exposed and unexposed to the compounds in question, were collected along with sediments for laboratory testing. The study showed that in vitro gonadal incubation levels of steroid production were lower at the tributary sites within the oil sands deposits. One indicator of exposure to oil sands related compounds (hepatic 7-ethoxyresorufin-O-deethylase activity) was shown to be 5 times higher at the same sites. In addition, slimy sculpin were exposed to sediment samples from the Steepbank River site for 4 to 8 days to evaluate the absorption of the indicator. The indicator in exposed fish was found to be comparable to that measured in fish native to the oil sands area. The study was not capable of predicting an altered ability of gonadal tissue of exposed fish to produce steroid hormones in vitro. It was concluded that future development could compromise the reproductive health of fish in the area

  10. Fish impingement at estuarine power stations and its significance to commercial fishing

    International Nuclear Information System (INIS)

    Turnpenny, A.W.H.

    1989-01-01

    The abstraction of cooling water (CW) at power stations sited on tidal waters inevitably leads to mortalities of some fish which are drawn in with the CW supply and become impinged on the intake screens. These fish are predominantly 0- or 1-group juveniles which, owing to their small size, are unable to resist intake currents. Commercial fishermen often object to the fact that juvenile fish are killed in this way. Their concern stems from the fact that in order to protect stocks, commercial fishing is restricted to fish which are above a statutory minimum landing size, whereas the majority of fish killed by impingement are below this size. This Report considers the significance of impingement mortalities at four estuarine sites in Britain for six commercially important species. Life tables are used to establish expected survival trajectories for each species and to compute reproductive potential. Each fish killed on intake screens is then considered in terms of the fraction of the reproductive potential of a single adult at maturity, and is ascribed an 'adult equivalent' value. Total catches of mixed juveniles and adults are then presented as 'adult equivalent' values. (author)

  11. 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...

  12. Abundance and diversity of aquatic macroinvertebrate communities in lakes exposed to Chernobyl-derived ionising radiation

    International Nuclear Information System (INIS)

    Murphy, J.F.; Nagorskaya, L.L.; Smith, J.T.

    2011-01-01

    Littoral (lake shore) macroinvertebrate communities were studied in eight natural lakes affected by fallout from the Chernobyl accident. The lakes spanned a range in 137 Cs 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 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 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 relationship between

  13. Drivers of fishing at the household scale in Fiji

    Directory of Open Access Journals (Sweden)

    Rachel Dacks

    2018-03-01

    Full Text Available Coral reefs sustain millions of people worldwide, yet in recent years, social, environmental, and climate change have caused major declines in coral reef fisheries. Small-scale coral reef fisheries research has largely focused on community-level drivers of fishing, ignoring the heterogeneities that exist within communities. We used social-ecological indicators from 20 coastal villages in Fiji to identify potential fine-scale, context-appropriate drivers of estimated household fish catch. Indicators were developed based on a review of the literature, discussions with local experts, and a pilot study. Using structural equation models, we found that importance of fishing to income, household fish consumption, livelihood diversity, travel time to market, and coral reef area all positively affect estimated household-level fish catch. Our results contrast with findings from other larger scale studies by identifying that households further from markets had higher fishing frequency. We highlight the role of middlemen in these small-scale fisheries, who have been largely overlooked as drivers of fisheries catch. Our findings emphasize the need for household-level analyses to better understand the complexities in coral reef social-ecological systems to more effectively manage small-scale fisheries in communities.

  14. Influence of seasonal, diel, lunar, and other environmental factors on upstream fish passage in the igarapava fish ladder, Brazil

    Science.gov (United States)

    Bizzotto, P.M.; Godinho, Alexandre L.; Vono, V.; Kynard, B.; Godinho, Hugo P.

    2009-01-01

    Upstream fish passage was evaluated during 12 months in the vertical-slot Igarapava Fish Ladder constructed around Igarapava Dam, in the heavily dammed Grande River, Southeast Brazil. A video monitoring system was used to observe 61,621 fish that passed the ladder, of which 93.5% were identified to 15 taxa. Among the migratory species, the most abundant were Pimelodus maculatus (33.6% of all fish), Leporinus octofasciatus (31.4%), Leporinus friderici (4.5%), and Prochilodus lineatus (3.1%). Seven taxa were classified as nonmigratory, and of these taxa, the small Bryconamericus stramineus was the most abundant (12.7%) of all fishes. Passage of the 'nonmigratory' taxa upstream in the ladder shows they are migratory in this system and have a strong behavioural drive to move to upstream habitat. Passage of most taxa had a strong seasonal pattern. While some species passed primarily during the day, others showed a distinct nocturnal pattern. Lunar phase and water temperature also strongly affected passage of some taxa. Rainfall and dam discharge had a small or null influence on most taxa; perhaps due to the fairly small catchment area of the reservoir and the highly regulated discharge at Igarapava Dam. ?? 2009 John Wiley & Sons A/S.

  15. Abundance and tidal behaviour of pelagic fish in the gateway to the Wadden Sea

    NARCIS (Netherlands)

    Couperus, B.; Gastauer, S.; Fässler, S.M.M.; Tulp, I.; van der Veer, H.W.; Poos, J.J.

    2016-01-01

    The shallow coast of The Netherlands is an important habitat for small pelagic fish. They form one of the major links between plankton and the higher trophic levels. Predatory fish, sea mammals and birds rely on small pelagic fish as a major food source. Currently, monitoring of fish in the Dutch

  16. Threatened fish and fishers along the Brazilian Atlantic Forest Coast.

    Science.gov (United States)

    Begossi, Alpina; Salivonchyk, Svetlana; Hallwass, Gustavo; Hanazaki, Natalia; Lopes, Priscila F M; Silvano, Renato A M

    2017-12-01

    Small-scale fisheries of the Brazilian Atlantic Forest Coast (BAFC) depend on fish resources for food and income. Thus, if the catch diminishes or if fish species that are a target for fishers are overexploited or impacted, this could affect fishers' livelihoods. The exclusion of threatened fish species from the catch is believed to be a threat to small-scale fisheries, which is likely to be the case along the BAFC. Many fish species are currently listed as threatened or vulnerable, whereas there is not enough biological information available to determine the status of the majority of the other species. Failure to protect the BAFC biodiversity might negatively impact fishers' income and the regional economy of local small-scale fisheries. We collected data from 1986 to 2009 through 347 interviews and 24-h food recall surveys at seven southeastern coastal sites of the Atlantic Forest. We show that important species of consumed fish are currently threatened: of the 65 species mentioned by fishers as the most consumed fishes, 33% are decreasing and 54% have an unknown status. Thus, biological and ecological data for BAFC marine species are urgently needed, along with co-management, to promote fish conservation.

  17. 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.

  18. Ecological, groundwater, and human health risk assessment in a mining region of Nicaragua.

    Science.gov (United States)

    Picado, Francisco; Mendoza, Alfredo; Cuadra, Steven; Barmen, Gerhard; Jakobsson, Kristina; Bengtsson, Göran

    2010-06-01

    The objective of the present study was to integrate the relative risk from mercury exposure to stream biota, groundwater, and humans in the Río Artiguas (Sucio) river basin, Nicaragua, where local gold mining occurs. A hazard quotient was used as a common exchange rate in probabilistic estimations of exposure and effects by means of Monte Carlo simulations. The endpoint for stream organisms was the lethal no-observed-effect concentration (NOECs), for groundwater the WHO guideline and the inhibitory Hg concentrations in bacteria (IC), and for humans the tolerable daily intake (TDI) and the benchmark dose level with an uncertainty factor of 10 (BMDLs(0.1)). Macroinvertebrates and fish in the contaminated river are faced with a higher risk to suffer from exposure to Hg than humans eating contaminated fish and bacteria living in the groundwater. The river sediment is the most hazardous source for the macroinvertebrates, and macroinvertebrates make up the highest risk for fish. The distribution of body concentrations of Hg in fish in the mining areas of the basin may exceed the distribution of endpoint values with close to 100% probability. Similarly, the Hg concentration in cord blood of humans feeding on fish from the river was predicted to exceed the BMDLs(0.1) with about 10% probability. Most of the risk to the groundwater quality is confined to the vicinity of the gold refining plants and along the river, with a probability of about 20% to exceed the guideline value.

  19. Coldwater fish in wadeable streams [Chapter 8

    Science.gov (United States)

    Jason B. Dunham; Amanda E. Rosenberger; Russell F. Thurow; C. Andrew Dolloff; Philip J. Howell

    2009-01-01

    Small, wadeable streams comprise the majority of habitats available to fishes in fluvial networks. Wadeable streams are generally less than 1 m deep, and fish can be sampled without the use of water craft. Cold waters are defined as having mean 7-d summer maximum water temperatures of less than 20°C and providing habitat for coldwater fishes.

  20. Tendency in fishing development and fish consumption in Serbia

    Directory of Open Access Journals (Sweden)

    Tešić Milan

    2013-01-01

    Full Text Available Production and catch of fish in Serbia increases from year to year, while in the world it reached its peak at the beginning of this century. Serbia has all the favorable natural and economic conditions for further development of fishing. Out of total production, that is, annual fish catch in Serbia, the greatest part is sold by organized purchase, lower part is exported, and the reminder goes to the market through retail. It is well known that food consumption, therefore fish consumption, depends on several factors such as the production level, retail price, consumers purchasing power and their eating habits. Therefore, when analyzing the tendency of production and consumption of fish in Serbia, it is important to investigate the influence of production, price and purchasing power of consumers on it. In order to investigate the set objective, there were used corresponding quantitative data obtained by Statistical Office of the Republic of Serbia. On the basis of the original data, there were determined certain parameters, which were used as variables for calculation of correlational-regressive and maginal analysis for determining the elasticity of demand and consummation of fish per capita in Serbia. Production and catch of fish in Serbia tended to increase during the observed period, with annual growth rate of 17.4%. Beside the fact that annual growth rate is 4.8%, fish consumption per capita in Serbia is still quite small (X=4.89kg, what is a consequence of population habit to consume predominantly meat. In our study we have found out that fish consumption in Serbia mostly depend on fish production per capita (rxy=0.6364, as well as on groos (rxy=0.6045 and net (rxy=0.5969 earnings. Also, it is determined that consumption elasticity has the highest growth in regard to fish production per capita. [Projekat Ministarstva nauke Republike Srbije, br. TR 31011

  1. Abundance and tidal behaviour of pelagic fish in the gateway to the Wadden Sea

    NARCIS (Netherlands)

    Couperus, Bram; Gastauer, Sven; Fässler, Sascha M.M.; Tulp, Ingrid; Veer, van der Henk W.; Poos, Jan Jaap

    2016-01-01

    The shallow coast of The Netherlands is an important habitat for small pelagic fish. They form one of the major links between plankton and the higher trophic levels. Predatory fish, sea mammals and birds rely on small pelagic fish as a major food source. Currently, monitoring of fish in the Dutch

  2. δ18O of apatite phosphate in small pelagic fish: insights from wild-caught and tank-grown specimens

    Science.gov (United States)

    Lambert, T.; Javor, B.; Paytan, A.

    2011-12-01

    Oxygen isotope ratios of mineralized structures in fish reflect the temperature and isotopic composition of the water in which they grow. For bulk samples (e.g., whole scales, bones, and otoliths), understanding how this signal is integrated across time and space is critical, especially for organisms exposed to high variability in growth conditions. Here, we assess the response of fish scale δ18O (from apatite phosphate) to experimentally manipulated water conditions. Wild-caught sardines were grown at controlled temperatures (13°C, 17°C, and 21°C) for 11 months. Higher growth temperatures correlated to lower δ18O values, representing a combination of scale apatite deposited before and after the temperature manipulation. Models that account for both biomineral allometry and exposure to varying water properties (e.g., by overlaying migration routes, isoscapes, and temperature maps) have the potential to quantify the varying contributions of minerals grown under different conditions. We use this method to predict δ18O of apatite phosphate for small pelagic fish found in California coastal waters, then compare expected values to those obtained from collected samples. Since phosphate oxygen is relatively resistant to diagenesis, this modern calibration establishes a framework for paleo studies.

  3. Long Term Resource Monitoring Program Annual Status Report, 1999: Macroinvertebrate Sampling in Six Reaches of the Upper Mississippi River System

    National Research Council Canada - National Science Library

    Sauer, Jennifer

    2000-01-01

    In 1992, macroinvertebrate sampling was initiated in Pools 4, 8, 13, 26, and the Open River reach of the Mississippi River, and La Orange Pool of the Illinois River as part of the Long Term Resource Monitoring Program...

  4. Macroinvertebrates in North American tallgrass prairie soils: effects of fire, mowing, and fertilization on density and biomass

    Science.gov (United States)

    M.A. Callaham; J.M. Blair; T.C. Todd; D.J. Kitchen; M.R. Whiles

    2003-01-01

    The responses of tallgrass prairie plant communities and ecosystem processes to fire and grazing are well characterized. However, responses of invertebrate consumer groups. and particularly soil-dwelling organisms, to these disturbances are not well known. At Konza Prairie Biological Station. we sampled soil macroinvertebrates in 1994 and 1999 as part of a long-term...

  5. The Effect of Community-Based Soil and Water Conservation Practices on Abundance and Diversity of Soil Macroinvertebrates in the Northern Highlands of Ethiopia

    Directory of Open Access Journals (Sweden)

    Mengistu Welemariam

    2018-04-01

    Full Text Available Soil and water conservation (SWC practices in the northern highlands of Ethiopia have important implications for land restoration and biodiversity recovery. The present study determined soil macroinvertebrate (SMI abundance and diversity in response to spatial conditions i.e., generated by different conservation practices, soil depth, and temporal seasonality with the wet and dry season. The SWC practices considered were exclosure + terrace, exclosure alone, terraces, and non-conserved grazing lands. Each SWC measure was selected in three sites that were considered as replications due to low heterogeneity in terms of human and livestock disturbances and biophysical factors. Soil macroinvertebrates were collected using a monolith according to tropical soil biology and fertility (TSBF method. The highest density (55% of SMI was found in exclosures followed by terraces 26%. Non-conserved communal grazing lands account for only 19% of the total. Shannon diversity index was significantly (P < 0.05 higher (1.21 in the exclosures supported with terraces and the lowest (0.9 was observed in the non-conserved communal grazing lands. Diversity was also significantly (P < 0.05 higher (1.26 in wet than dry season (0.70. The highest (41% Sorensen similarity index among SMI was found between exclosures with terraces and exclosures alone during the wet season. The lowest (20% Sorensen similarity index was found between terraces alone and exclosures with terraces in dry season. Soil macroinvertebrate abundance was higher in upper (0–10 cm than lower (10–20 and 20–30 cm soil depth. Soil macroinvertebrate abundance was positively and strongly correlated with soil moisture (R2 = 0.85 and soil organic carbon stock (R2 = 0.95. However, it was negatively (R2 = −0.71 correlated with bulk density. Generally, the abundance and diversity of SMI increased as exclosures and communal grazing lands are supported with terraces.

  6. Assessing condition of macroinvertebrate communities and bed sediment toxicity in the Rochester Embayment Area of Concern, New York, USA

    Science.gov (United States)

    Duffy, Brian; George, Scott D.; Baldigo, Barry P.; Smith, Alexander J.

    2017-01-01

    The United States and Canada agreed to restore the chemical, physical, and biological integrity of the Great Lakes ecosystem under the first Great Lakes Water Quality Agreement in 1972. The lowest reach of the Genesee River and the Rochester Embayment on Lake Ontario between Bogus Point and Nine Mile Point, including Braddock Bay, were designated as an Area of Concern (AOC) due to effects of contaminated sediments and physical disturbance on several beneficial uses. Following sediment remedial efforts and with conditions improving in the AOC, the present study was conducted to reevaluate the status of the benthic macroinvertebrate (benthos) beneficial use impairment (BUI). Benthic macroinvertebrate community assessments and 10-day Chironomus dilutus bioassays were used to test the hypotheses that sediments within the AOC were no more toxic than sediments from surrounding reference areas. The study was separated into three discrete systems (Genesee River, Lake Ontario, and Braddock Bay) and non-parametric analyses determined that a multimetric index of benthic macroinvertebrate community integrity was significantly higher at AOC sites compared to reference sites on the Genesee River and in Braddock Bay while AOC and reference sites on Lake Ontario did not differ significantly. Survival and growth of C. dilutus were also similar between AOC and reference sites for each system with the exception of significantly higher growth at reference sites on Lake Ontario. Results generally indicated that the condition of benthos and toxicity of sediment of the Rochester Embayment AOC are similar to or better than that in the surrounding area.

  7. 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.

  8. Effects of grade control structures on fish passage, biological assemblages, and hydraulic environments in western Iowa streams: a multidisciplinary review

    Science.gov (United States)

    Thomas, J.T.; Culler, M.E.; Dermisis, D.C.; Pierce, Clay; Papanicolaou, A.N.; Stewart, T.W.; Larson, C.J.

    2011-01-01

    Land use changes and channelization of streams in the deep loess region of western Iowa have led to stream channel incision, altered flow regimes, increased sediment inputs, decreased habitat diversity and reduced lateral connectivity of streams and floodplains. Grade control structures (GCSs) are built in streams to prevent further erosion, protect infrastructure and reduce sediment loads. However, GCS can have a detrimental impact on fisheries and biological communities. We review three complementary biological and hydraulic studies on the effects of GCS in these streams. GCS with steep (≥1:4 rise : run) downstream slopes severely limited fish passage, but GCS with gentle slopes (≤1:15) allowed greater passage. Fish assemblages were dominated by species tolerant of degradation, and Index of Biotic Integrity (IBI) scores were indicative of fair or poor biotic integrity. More than 50% of fish species had truncated distributions. After modification of GCS to reduce slopes and permit increased passage, IBI scores increased and several species were detected further upstream than before modification. Total macroinvertebrate density, biomass and taxonomic diversity and abundance of ecologically sensitive taxa were greater at GCS than in reaches immediately upstream, downstream or ≥1 km from GCS. A hydraulic study confirmed results from fish passage studies; minimum depths and maximum current velocities at GCS with gentle slopes (≤1:15) were more likely to meet minimum criteria for catfish passage than GCS with steeper slopes. Multidisciplinary approaches such as ours will increase understanding of GCS-associated factors influencing fish passage, biological assemblage structure and other ecological relationships in streams.

  9. Impact of heated waters on water quality and macroinvertebrate community in the Narew River (Poland

    Directory of Open Access Journals (Sweden)

    Krolak Elzbieta

    2017-07-01

    Full Text Available The effect of heated waters from coal-burning power stations on the water parameters and the occurrence of macroinvertebrates depends on the individual characteristics of the river to which the heated waters are discharged. The objective of the study was to assess the impact of heated water from the Ostrołęka Power Station on selected water properties and the macroinvertebrate community in the Narew River. Samples were collected in years: 2013-2016 along two river stretches: upstream and downstream of the canal. The water temperature was higher and the oxygen concentrations were lower at the downstream sites compared to the upstream sites of the canal. The values of conductivity, concentrations of nitrates, phosphates, chlorides and calcium were similar at the sampling sites. A total of 33 families of macrozoobenthos were found. The numbers of families were positively correlated with the temperature and conductivity and negatively correlated with oxygen. The heated waters were found to have no effect on the Shannon-Wiener diversity index. The inflow of heated waters increased the percentage of Gammaridae, represented by species Dikerogammarus haemobaphes (Eichwald, 1841 and decreased the percentage of Chironomidae. The presence of the thermophilous bivalve Sinanodonta woodiana (Lea, 1934 was noted downstream of the canal.

  10. Better processing and marketing of healthy fish products in Malawi

    International Development Research Centre (IDRC) Digital Library (Canada)

    : small fish, in particular, are a vital source of calcium, vi- tamin A, iron, and zinc. Once caught, most fish are sun-dried, smoked, parboiled, or pan roasted. However, peak fish catches in Malawi coincide with seasonal rains and high humidity,.

  11. Use of tolerance values to diagnose water-quality stressors to aquatic biota in New England streams

    Science.gov (United States)

    Meador, M.R.; Carlisle, D.M.; Coles, J.F.

    2008-01-01

    Identification of stressors related to biological impairment is critical to biological assessments. We applied nationally derived tolerance indicator values for four water-quality variables to fish and benthic macroinvertebrate assemblages at 29 sites along an urban gradient in New England. Tolerance indicator values (TIVs), as biologically based predictors of water-quality variables, were determined for dissolved oxygen, nitrite plus nitrate (nitrate), total phosphorus, and water temperature for each site based on observed biological assemblages (TIVO), and for expected assemblages (TIVE). The quotient method, based on a ratio of the TIVs for observed and expected assemblages (tolerance units), was used to diagnose potential water-quality stressors. In addition, the ratio of measured water-quality values to water-quality criteria (water-quality units) was calculated for each water-quality variable to assess measured water-quality stressors. Results from a RIVPACS predictive model for benthic macroinvertebrates and Bray-Curtis dissimilarity for fish were used to classify sites into categories of good or impaired ecological condition. Significant differences were detected between good and impaired sites for all biological tolerance units (fish and benthic macroinvertebrate assemblages averaged) except for nitrate (P = 0.480), and for all water-quality units except for nitrate (P = 0.183). Diagnosis of water-quality stressors at selected sites was, in general, consistent with State-reported causes of impairment. Tolerance units for benthic macroinvertebrate and fish assemblages were significantly correlated for water temperature (P = 0.001, r = 0.63), dissolved oxygen (P = 0.001, r = 0.61), and total phosphorus (P = 0.001, r = 0.61), but not for nitrate (P = 0.059, r = -0.35). Differences between the two assemblages in site-specific diagnosis of water-quality stressors may be the result of differences in nitrate tolerance.

  12. Morphology and small subunit rDNA-based phylogeny of Ceratomyxa amazonensis n. sp. parasite of Symphysodon discus, an ornamental freshwater fish from Amazon.

    Science.gov (United States)

    Mathews, Patrick D; Naldoni, Juliana; Maia, Antonio A; Adriano, Edson A

    2016-10-01

    The specious genus Ceratomyxa Thélodan, 1892, infect mainly gallbladder of marine fishes, with only five species reported infecting species from freshwater environment. This study performed morphological and phylogenetic analyses involving a new Ceratomyxa species (Ceratomyxa amazonensis n. sp.) found in gallbladder of Symphysodon discus Heckel, 1840 (Perciformes: Cichlidae), an important ornamental fish endemic to Amazon basin. Mature spores were strongly arcuate shaped and measured 7.0 ± 0.3 (6.2-7.6) μm in length, 15.8 ± 0.4 (15.0-16.7) μm in thickness, and polar capsules 3.22 ± 0.34 (2.4-3.6) μm in length and 2.63 ± 0.17 (2.4-2.9) μm in width. This was the first small subunit ribosomal DNA (SS rDNA) sequencing performed to Ceratomyxa species parasite of freshwater fish, and the phylogenetic analysis showed C. amazonensis n. sp. clustering in the early diverging subclade of the ceratomyxids, together with species of parasites of amphidromous/estuaries fishes, suggesting some role of the transition of the fishes between marine/freshwater environments in the evolutionary history of these parasites.

  13. Effects of historical lead–zinc mining on riffle-dwelling benthic fish and crayfish in the Big River of southeastern Missouri, USA

    Science.gov (United States)

    Allert, A.L.; DiStefano, R.J.; Fairchild, J.F.; Schmitt, C.J.; McKee, M.J.; Girondo, J.A.; Brumbaugh, W.G.; May, T.W.

    2013-01-01

    The Big River (BGR) drains much of the Old Lead Belt mining district (OLB) in southeastern Missouri, USA, which was historically among the largest producers of lead–zinc (Pb–Zn) ore in the world. We sampled benthic fish and crayfish in riffle habitats at eight sites in the BGR and conducted 56-day in situ exposures to the woodland crayfish (Orconectes hylas) and golden crayfish (Orconectes luteus) in cages at four sites affected to differing degrees by mining. Densities of fish and crayfish, physical habitat and water quality, and the survival and growth of caged crayfish were examined at sites with no known upstream mining activities (i.e., reference sites) and at sites downstream of mining areas (i.e., mining and downstream sites). Lead, zinc, and cadmium were analyzed in surface and pore water, sediment, detritus, fish, crayfish, and other benthic macro-invertebrates. Metals concentrations in all materials analyzed were greater at mining and downstream sites than at reference sites. Ten species of fish and four species of crayfish were collected. Fish and crayfish densities were significantly greater at reference than mining or downstream sites, and densities were greater at downstream than mining sites. Survival of caged crayfish was significantly lower at mining sites than reference sites; downstream sites were not tested. Chronic toxic-unit scores and sediment probable effects quotients indicated significant risk of toxicity to fish and crayfish, and metals concentrations in crayfish were sufficiently high to represent a risk to wildlife at mining and downstream sites. Collectively, the results provided direct evidence that metals associated with historical mining activities in the OLB continue to affect aquatic life in the BGR.

  14. Evidence for responses in water chemistry and macroinvertebrates in a strongly acidified mountain stream

    Czech Academy of Sciences Publication Activity Database

    Beneš, F.; Horecký, J.; Senoo, T.; Kamasová, L.; Lamačová, Anna; Tátosová, J.; Hardekopf, D. W.; Stuchlík, Evžen

    2017-01-01

    Roč. 72, č. 9 (2017), s. 1049-1058 ISSN 0006-3088 R&D Projects: GA ČR(CZ) GA17-05935S; GA ČR(CZ) GA15-08124S Institutional support: RVO:86652079 ; RVO:60077344 Keywords : acidified mountain stream * macroinvertebrates * logging * hydrological patterns * recovery Subject RIV: EH - Ecology, Behaviour; EH - Ecology, Behaviour (BC-A) OBOR OECD: Environmental sciences (social aspects to be 5.7); Environmental sciences (social aspects to be 5.7) (BC-A) Impact factor: 0.759, year: 2016

  15. Development of a Macroinvertebrate - based Index of Biotic Integrity (M-IBI for Colombo-Sri Jayawardhanapura Canal System (A new approach to assess stream/ wetland health

    Directory of Open Access Journals (Sweden)

    N. Nilakarawasam

    2012-05-01

    Full Text Available Macroinvertebrates have been identified as excellent indicators of stream (wetland health as they respond rapidly to environmental changers and provide short to medium term pollution history records. Current study was aimed to develop a Macroinvertebrate-based Index of Biotic Integrity (M-IBI to monitor stream health of Colombo-Sri Jayawardhanapura canal system. Macroinvertebrates were sampled using a D-framed kick net from ten stations during the period of Nov 2008 to June 2009. Habitat characteristics and some water quality parameters also recorded. For the index development, those ten stations were grouped into two as ’Reference’ and ‘Degraded’ based on their habitat characteristics and some water quality parameters. Then 41vcandidate metrics were nominated for statistical analysis process. After considering their sensitivity to stream impairment, ability of showing exceptionally strong discrimination between reference and degraded sites and less redundancy, ten candidate metrics were selected for M-IBI development. Validity of the index was tested with a new independent data set. Scores acquired for these data set were positively correlated with DO values (r = 0.578. That concluded the potential of using M-IBI developed for biological monitoring and improving biotic integrity of streams and wetlands.

  16. 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

  17. [Relationship between leaf litter decomposition and colonization of benthic macroinvertebrates during early frost period in a headwater stream in the Changbai Mountains, Northeast China].

    Science.gov (United States)

    Wang, Lu; Yang, Hai Jun; Li, Ling; Nan, Xiao Fei; Zhang, Zhen Xing; Li, Kun

    2017-11-01

    Annually, about 70% of the streams in the Changbai Mountains are frosted during November to April, with manifest seasonal freeze-thaw characters. By using monoculture and mixing leaf litters of Tilia amurensis, Acer mono and Quecus mongolica, this research attempted to disentangle the relationship between leaf litter decomposition and colonization of macroinvertebrates in the stream during early frost period. A 35-day investigation was carried out in a headwater stream of the Changbai Mountains. Nylon bags with two hole sizes (5 mm and 0.3 mm) were used to examine decomposition of the litters. The results showed that the mass losses were significantly different among the three kinds of leaf litters in monoculture, whose decomposition rates descended as A. mono, T. amurensis, and Q. mongolica, however, there existed no significant difference among the litter mixing. Mass losses in both mesh bags all showed little difference, except T. amurensis and the mixed litters. Litter mixing effects occurred in the coarse mesh bags with A. mono and Q. mongolica, but no mixture effects for others. Community structures of the macroinvertebrates colonizing in the litter bags differed with each other, but shredders' density had no significant difference among the three litters, and the mixing effects on shredders were poor. Our results implied that microbes play the major decomposers of leaf litters, and macroinvertebrates contribute little to the decomposition in the early frost period. Despite shredder's density is lower, they determine the mixing effects of litters. Macroinvertebrates are selective to food and habitats, however, due to the short term colonizing, and the influence of leaf litters on shredders is still unsure. Our results might contribute to understanding the cold season ecological processes and related management issues of headwater stream ecosystem.

  18. 76 FR 3126 - Final Determination of the Assistant Administrator for Water Pursuant to Section 404(c) of the...

    Science.gov (United States)

    2011-01-19

    ... macroinvertebrates, up to 46 species of amphibians and reptiles, 4 species of crayfish, and 5 species of fish, as... amphibians, reptiles, crayfish, and bird species that depend on downstream waters for food or habitat... be, in turn, substantial effects on fish, amphibian, and bird populations that rely on these...

  19. Baseline for Climate Change: Modeling Watershed Aquatic Biodiversity Relative to Environmental and Anthropogenic Factors

    Energy Technology Data Exchange (ETDEWEB)

    Maurakis, Eugene G

    2010-10-01

    Objectives of the two-year study were to (1) establish baselines for fish and macroinvertebrate community structures in two mid-Atlantic lower Piedmont watersheds (Quantico Creek, a pristine forest watershed; and Cameron Run, an urban watershed, Virginia) that can be used to monitor changes relative to the impacts related to climate change in the future; (2) create mathematical expressions to model fish species richness and diversity, and macroinvertebrate taxa and macroinvertebrate functional feeding group taxa richness and diversity that can serve as a baseline for future comparisons in these and other watersheds in the mid-Atlantic region; and (3) heighten people’s awareness, knowledge and understanding of climate change and impacts on watersheds in a laboratory experience and interactive exhibits, through internship opportunities for undergraduate and graduate students, a week-long teacher workshop, and a website about climate change and watersheds. Mathematical expressions modeled fish and macroinvertebrate richness and diversity accurately well during most of the six thermal seasons where sample sizes were robust. Additionally, hydrologic models provide the basis for estimating flows under varying meteorological conditions and landscape changes. Continuations of long-term studies are requisite for accurately teasing local human influences (e.g. urbanization and watershed alteration) from global anthropogenic impacts (e.g. climate change) on watersheds. Effective and skillful translations (e.g. annual potential exposure of 750,000 people to our inquiry-based laboratory activities and interactive exhibits in Virginia) of results of scientific investigations are valuable ways of communicating information to the general public to enhance their understanding of climate change and its effects in watersheds.

  20. Population Structure and Adaptive Divergence in a High Gene Flow Marine Fish: The Small Yellow Croaker (Larimichthys polyactis.

    Directory of Open Access Journals (Sweden)

    Bing-Jian Liu

    Full Text Available The spatial distribution of genetic diversity has been long considered as a key component of policy development for management and conservation of marine fishes. However, unraveling the population genetic structure of migratory fish species is challenging due to high potential for gene flow. Despite the shallow population differentiation revealed by putatively neutral loci, the higher genetic differentiation with panels of putatively adaptive loci could provide greater resolution for stock identification. Here, patterns of population differentiation of small yellow croaker (Larimichthys polyactis were investigated by genotyping 15 highly polymorphic microsatellites in 337 individuals of 15 geographic populations collected from both spawning and overwintering grounds. Outlier analyses indicated that the locus Lpol03 might be under directional selection, which showed a strong homology with Grid2 gene encoding the glutamate receptor δ2 protein (GluRδ2. Based on Lpol03, two distinct clusters were identified by both STRUCTURE and PCoA analyses, suggesting that there were two overwintering aggregations of L. polyactis. A novel migration pattern was suggested for L. polyactis, which was inconsistent with results of previous studies based on historical fishing yield statistics. These results provided new perspectives on the population genetic structure and migratory routes of L. polyactis, which could have significant implications for sustainable management and utilization of this important fishery resource.

  1. Relationships between indicators of acid-base chemistry and fish assemblages in streams of the Great Smoky Mountains National Park

    Science.gov (United States)

    Baldigo, Barry P.; Kulp, Matt A.; Schwartz, John S.

    2018-01-01

    The acidity of many streams in the Great Smoky Mountains National Park (GRSM) has increased significantly since pre-industrial (∼1850) times due to the effects of highly acidic atmospheric deposition in poorly buffered watersheds. Extensive stream-monitoring programs since 1993 have shown that fish and macroinvertebrate assemblages have been adversely affected in many streams across the GRSM. Matching chemistry and fishery information collected from 389 surveys performed at 52 stream sites over a 22-year period were assessed using logistic regression analysis to help inform the U.S. Environmental Protection Agency’s assessment of the environmental impacts of emissions of oxides of nitrogen (NOx) and sulfur (SOx). Numerous logistic equations and associated curves were derived that defined the relations between acid neutralizing capacity (ANC) or pH and different levels of community richness, density, and biomass; and density and biomass of brook trout, rainbow trout, and small prey (minnow) populations in streams of the GRSM. The equations and curves describe the status of fish assemblages in the GRSM under contemporary emission levels and deposition loads of nitrogen (N) and sulfur (S) and provide a means to estimate how newly proposed (and various alternative) target deposition loads, which strongly influence stream ANC, might affect key ecological indicators. Several examples using ANC, community richness, and brook trout density are presented to illustrate the steps needed to predict how future changes in stream chemistry (resulting from different target deposition loads of N and S) will affect the probabilities of observing specific levels of selected biological indicators in GRSM streams. The implications of this study to the regulation of NOx and SOx emissions, water quality, and fisheries management in streams of the GRSM are discussed, but also qualified by the fact that specific examples provided need to be further explored before recommendations

  2. The Benthonic Macroinvertebrates of Pozo Azul (Gaira River Basin, Colombia and their Relationship with Water Quality

    Directory of Open Access Journals (Sweden)

    Francisco Guerrero-Bolaño

    2003-07-01

    Full Text Available On July 2002, a study of some physicochemical parameters and their relationship with the benthonic macroinvertebrates community structure on four coriotypes: stone, trash, silt and macrophytes, was carried out in Pozo Azul (Gaira River basin, Magdalena, Colombia. The physicochemical parameters were determined, to a considerable extent, by the geographic characteristics of the system. The water was found to be oxygen saturated, and intermediate compounds of the organic matter stabilization, such as nitrites and ammonium, there were found 588 individuals distributed in 11 orders and 38 families. The most representative orders were Trichoptera, Coleoptera, Diptera and Ephemeroptera. The most representative families were Baetidae, Simullidae, Perlidae, Chironomidae, and Hydropsychidae, in this rank of abundance. The BMWP index for the relationship between the community structure and the water quality (adapted by Universidad del Valle, Cali, Colombia was calculated. According to this index the water quality was optimum. Also, given the general characteristics of the site studied, the water mass quality was classified as good and oligosaprobit, based on the saprobit ecology. It is possible that this state was reached due to stabilization after a small perturbation induced by coffee cultivation in the zone.

  3. IMPACT OF HEAVY METALS CONTAMINATION ON SPRING ABUNDANCE OF AQUATIC MACRO-INVERTEBRATES INHABITING LAKE TIMSAH, EGYPT

    Directory of Open Access Journals (Sweden)

    Marwa Ibrahim Saad El-Din

    2017-04-01

    Full Text Available Lake Timsah, Egypt receives several kinds of pollutants coming from domestic sewage of unconnected areas adjoining the shore and possibly marine pollution. During the last decades heavy metals have become common contaminants of aquatic and wetland environments throughout the world because of human activity and technological development. Increasing attention has been given during the last decade to the protection of marine and freshwater aquatic environment against pollution, both nationally and internationally. Macro-benthoses are the most commonly organisms used as bio-indicators water quality assessment. All of the aquatic macro-invertebrates that were collected from El-Taween station, Lake Timsah, Egypt fell into three major groups that were fairly easy to identify. They were annelids (Polychaeta and Oligochaeta, molluscs (Bivalvia and Gastropoda and arthropods (Crustacea. The small sized crustacean Sphaeroma. serratum are considered suitable species for aquatic bio-monitoring because they hold an important position in the aquatic food chain responds to many pollutants, easy to culture and has short life cycles. Iron was most important determinant; it appears in high concentrations in both water sample and the tissue of crustacean sample (S. serratum.

  4. Small size today, aquarium dumping tomorrow: sales of juvenile non-native large fish as an important threat in Brazil

    Directory of Open Access Journals (Sweden)

    André L. B. Magalhães

    2017-12-01

    Full Text Available ABSTRACT Informal sales of large-bodied non-native aquarium fishes (known as “tankbusters” is increasing among Brazilian hobbyists. In this study, we surveyed this non-regulated trade on Facebook® from May 2012 to September 2016, systematically collecting information about the fishes available for trading: species, family, common/scientific names, native range, juvenile length, behavior, number of specimens available in five geographical regions from Brazil. We also assessed the invasion risk of the most frequently sold species using the Fish Invasiveness Screening Test (FIST. We found 93 taxa belonging to 35 families. Cichlidae was the dominant family, and most species were native to South America. All species are sold at very small sizes (< 10.0 cm, and most display aggressive behavior. The hybrid Amphilophus trimaculatus × Amphilophus citrinellus, Astronotus ocellatus, Uaru amphiacanthoides, Osteoglossum bicirrhosum, Cichla piquiti, Pangasianodon hypophthalmus, Datnioides microlepis and Cichla kelberi were the main species available. The southeast region showed the greatest trading activity. Based on biological traits, the FIST indicated that Arapaima gigas, C. kelberi and C. temensis are high-risk species in terms of biological invasions via aquarium dumping. We suggest management strategies such as trade regulations, monitoring, euthanasia and educational programs to prevent further introductions via aquarium dumping.

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

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    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,