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Sample records for stream invertebrate detrital

  1. Stream invertebrate productivity linked to forest subsidies: 37 stream-years of reference and experimental data

    Science.gov (United States)

    J. Bruce Wallace; Susan L Eggert; Judy L. Meyer; Jackson R. Webster

    2015-01-01

    Riparian habitats provide detrital subsidies of varying quantities and qualities to recipient ecosystems. We used long-term data from three reference streams (covering 24 stream-years) and 13-year whole-stream organic matter manipulations to investigate the influence of terrestrial detrital quantity and quality on benthic invertebrate community structure, abundance,...

  2. Stream invertebrate productivity linked to forest subsidies: 37 stream-years of reference and experimental data.

    Science.gov (United States)

    Wallace, J Bruce; Eggert, Susan L; Meyer, Judy L; Webster, Jackson R

    2015-05-01

    Riparian habitats provide detrital subsidies of varying quantities and qualities to recipient ecosystems. We used long-term data from three reference streams (covering 24 stream-years) and 13-year whole-stream organic matter manipulations to investigate the influence of terrestrial detrital quantity and quality on benthic invertebrate community structure, abundance, biomass, and secondary production in rockface (RF) and mixed substrates (MS) of forested headwater streams. Using a mesh canopy covering the entire treatment stream, we examined effects of litter ex'clusion, small- and large-wood removal, and addition of artificial wood (PVC) and leaves of varying quality on organic matter standing crops and invertebrate community structure and function. We assessed differences in functional feeding group distribution between substrate types as influenced by organic matter manipulations and long-term patterns of predator and prey production in manipulated vs. reference years. Particulate organic matter standing crops in MS of the treatment stream declined drastically with each successive year of litter exclusion, approaching zero after three years. Monthly invertebrate biomass and annual secondary production was positively related to benthic organic matter in the MS habitats. Rockface habitats exhibited fewer changes than MS habitats across all organic matter manipulations. With leaf addition, the patterns of functional group distribution among MS and RF habitats returned to patterns seen in reference streams. Secondary production per unit organic matter standing crop was greatest for the leaf addition period, followed by the reference streams, and significantly less for the litter exclusion and wood removal periods. These data indicate that the limited organic matter remaining in the stream following litter exclusion and wood removal was more refractory than that in the reference streams, whereas the added leaf material was more labile and readily converted into

  3. Benthic invertebrate fauna, small streams

    Science.gov (United States)

    J. Bruce Wallace; S.L. Eggert

    2009-01-01

    Small streams (first- through third-order streams) make up >98% of the total number of stream segments and >86% of stream length in many drainage networks. Small streams occur over a wide array of climates, geology, and biomes, which influence temperature, hydrologic regimes, water chemistry, light, substrate, stream permanence, a basin's terrestrial plant...

  4. Crayfish impact desert river ecosystem function and litter-dwelling invertebrate communities through association with novel detrital resources.

    Directory of Open Access Journals (Sweden)

    Eric K Moody

    Full Text Available Shifts in plant species distributions due to global change are increasing the availability of novel resources in a variety of ecosystems worldwide. In semiarid riparian areas, hydric pioneer tree species are being replaced by drought-tolerant plant species as water availability decreases. Additionally, introduced omnivorous crayfish, which feed upon primary producers, allochthonous detritus, and benthic invertebrates, can impact communities at multiple levels through both direct and indirect effects mediated by drought-tolerant plants. We tested the impact of both virile crayfish (Orconectes virilis and litter type on benthic invertebrates and the effect of crayfish on detrital resources across a gradient of riparian vegetation drought-tolerance using field cages with leaf litter bags in the San Pedro River in Southeastern Arizona. Virile crayfish increased breakdown rate of novel drought-tolerant saltcedar (Tamarix ramosissima, but did not impact breakdown of drought-tolerant seepwillow (Baccharis salicifolia or hydric Fremont cottonwood (Populus fremontii and Gooding's willow (Salix goodingii. Effects on invertebrate diversity were observed at the litter bag scale, but no effects were found at the cage scale. Crayfish decreased alpha diversity of colonizing macroinvertebrates, but did not affect beta diversity. In contrast, the drought-tolerant litter treatment decreased beta diversity relative to hydric litter. As drought-tolerant species become more abundant in riparian zones, their litter will become a larger component of the organic matter budget of desert streams which may serve to homogenize the litter-dwelling community and support elevated populations of virile crayfish. Through impacts at multiple trophic levels, crayfish have a significant effect on desert stream ecosystems.

  5. Detrital processing in streams exposed to acidic precipitation in the Central Appalachian Mountains

    International Nuclear Information System (INIS)

    Meegan, S.K.; Perry, S.A.; Perry, W.B.

    1996-01-01

    Continuing high rates of acidic deposition in the eastern United States may lead to long-term effects on stream communities, because sensitive catchments are continuing to lose anions and cations. A two-year study of the effects of pH and associated water chemistry variables on detrital processing in three streams with different bedrock geology in the Monongahela National Forest, West Virginia were investigated. Leaf pack processing rates and macroinvertebrate colonization and microbial biomass (ATP concentration) on the packs in the three stream were compared. It was found that macroinvertebrate and microbial communities differed both among streams that differed in their capacity to buffer the effects of acidic precipitation and among years in the same stream; these differences in biotic communities were not large enough to affect rates of leaf processing between the two years of the study, but they did significantly affect processing rates between acidic and circumneutral streams

  6. Seasonal species composition of invertebrates in several Oregon streams.

    Science.gov (United States)

    Pamela E. Porter; William R. Meehan

    1987-01-01

    The invertebrate communities ofeight Oregon streams were sampled seasonally from 1974 to 1976. Benthic, drift, and two types of aerial-trap samples were collected. Occurrence and percentage composition are summarized by sample type, season, and geographic area (coastal, Cascade, central, and eastern Oregon). Within 276 families, 426 taxa were identified; the 20...

  7. Flow effects on benthic stream invertebrates and ecological processes

    Science.gov (United States)

    Koprivsek, Maja; Brilly, Mitja

    2010-05-01

    Flow is the main abiotic factor in the streams. Flow affects the organisms in many direct and indirect ways. The organisms are directly affected by various hydrodynamic forces and mass transfer processes like drag forces, drift, shear stress, food and gases supply and washing metabolites away. Indirect effects on the organisms are determining and distribution of the particle size and structure of the substrate and determining the morphology of riverbeds. Flow does not affect only on individual organism, but also on many ecological effects. To expose just the most important: dispersal of the organisms, habitat use, resource acquisition, competition and predator-prey interactions. Stream invertebrates are adapted to the various flow conditions in many kinds of way. Some of them are avoiding the high flow with living in a hyporeic zone, while the others are adapted to flow with physical adaptations (the way of feeding, respiration, osmoregulation and resistance to draught), morphological adaptations (dorsoventrally flattened shape of organism, streamlined shape of organism, heterogeneous suckers, silk, claws, swimming hair, bristles and ballast gravel) or with behaviour. As the flow characteristics in a particular stream vary over a broad range of space and time scales, it is necessary to measure accurately the velocity in places where the organisms are present to determine the actual impact of flow on aquatic organisms. By measuring the mean flow at individual vertical in a single cross-section, we cannot get any information about the velocity situation close to the bottom of the riverbed where the stream invertebrates are living. Just measuring the velocity near the bottom is a major problem, as technologies for measuring the velocity and flow of natural watercourses is not adapted to measure so close to the bottom. New researches in the last two decades has shown that the thickness of laminar border layer of stones in the stream is only a few 100 micrometers, what

  8. Storage and export of organic matter in a headwater stream: responses to long-term detrital manipulations

    Science.gov (United States)

    Sue L. Eggert; J. Bruce Wallace; Judy L. Meyer; Jackson R. Webster

    2012-01-01

    Riparian habitats provide organic matter inputs that influence stream biota and ecosystem processes in forested watersheds. Over a 13-yr period, we examined the effects of litter exclusion, small- and large-wood removal, and the addition of leaf species of varying detrital quality on organic matter standing crop and export of organic and inorganic particles in a high-...

  9. Characterization and classification of invertebrates as indicators of flow permanence in headwater streams

    Science.gov (United States)

    Headwater streams represent a large proportion of river networks and many have temporary flow. Litigation has questioned whether these streams are jurisdictional under the Clean Water Act. Our goal was to identify indicators of flow permanence by comparing invertebrate assemblage...

  10. Detrital microbial community development and phosphorus dynamics in a stream ecosystem

    Energy Technology Data Exchange (ETDEWEB)

    Perkins, R.E.; Elwood, J.W.; Sayler, G.S.

    1986-06-01

    Detrital microbial community development and phosphorus dynamics in a lotic system were investigated in non-recirculating laboratory streams contains leaf detritus. Temporal patterns of microbial colonization, as determined by scanning electron microscopy, indicate leaf species dependency and that bacteria were the first colonizers followed by fungi. An extensive glycocalyx layer developed. Phosphorus incorporation rates of both the whole community and intracellular components were determined by time-course measurements of /sup 33/PO/sub 4/ or /sup 32/PO/sub 4/. Phosphorus turnover rates were determined by a sequential double-labeling procedure using /sup 33/PO/sub 4/ and /sup 32/PO/sub 4/, in which the microbiota were labeled with /sup 33/P until in isotopic equilibrium, then /sup 32/P was added. The turnover rate was determined by time-course measurements of the ratio /sup 32/P to /sup 33/P. Snail grazing resulted in an increase in phosphorus metabolism per unit microbial biomass; however, per unit area of leaf surface no increase was observed. Grazing also caused a two-fold reduction in microbial biomass. The results indicate that microbiota associated with decomposing leaves slowly recycle phosphorus, are slowly growing, and have a low metabolic activity. The spiraling length is shortened by microbiota on a short-term basis; however, it may increase on a long-term basis due to hydrological transport of detritus downstream.

  11. Detrital microbial community development and phosphorus dynamics in a stream ecosystem

    International Nuclear Information System (INIS)

    Perkins, R.E.; Elwood, J.W.; Sayler, G.S.

    1986-06-01

    Detrital microbial community development and phosphorus dynamics in a lotic system were investigated in non-recirculating laboratory streams contains leaf detritus. Temporal patterns of microbial colonization, as determined by scanning electron microscopy, indicate leaf species dependency and that bacteria were the first colonizers followed by fungi. An extensive glycocalyx layer developed. Phosphorus incorporation rates of both the whole community and intracellular components were determined by time-course measurements of 33 PO 4 or 32 PO 4 . Phosphorus turnover rates were determined by a sequential double-labeling procedure using 33 PO 4 and 32 PO 4 , in which the microbiota were labeled with 33 P until in isotopic equilibrium, then 32 P was added. The turnover rate was determined by time-course measurements of the ratio 32 P to 33 P. Snail grazing resulted in an increase in phosphorus metabolism per unit microbial biomass; however, per unit area of leaf surface no increase was observed. Grazing also caused a two-fold reduction in microbial biomass. The results indicate that microbiota associated with decomposing leaves slowly recycle phosphorus, are slowly growing, and have a low metabolic activity. The spiraling length is shortened by microbiota on a short-term basis; however, it may increase on a long-term basis due to hydrological transport of detritus downstream

  12. Invertebrates Associated with Coarse Woody Debris in Streams, Upland Forests, and Wetlands: A Review

    Science.gov (United States)

    A. Braccia; D.P. Batzer

    1999-01-01

    We reviewed literature on the inbvertebrate groups associated with coarse woody debris in forests, streams, and wetlands, and contrasted patterns of invertebrate community development and wood decomposition among ecosystems.

  13. Response of stream invertebrates to short-term salinization: A mesocosm approach

    International Nuclear Information System (INIS)

    Cañedo-Argüelles, Miguel; Grantham, Theodore E.; Perrée, Isabelle; Rieradevall, Maria; Céspedes-Sánchez, Raquel; Prat, Narcís

    2012-01-01

    Salinization is a major and growing threat to freshwater ecosystems, yet its effects on aquatic invertebrates have been poorly described at a community-level. Here we use a controlled experimental setting to evaluate short-term stream community responses to salinization, under conditions designed to replicate the duration (72 h) and intensity (up to 5 mS cm −1 ) of salinity pulses common to Mediterranean rivers subjected to mining pollution during runoff events. There was a significant overall effect, but differences between individual treatments and the control were only significant for the highest salinity treatment. The community response to salinization was characterized by a decline in total invertebrate density, taxon richness and diversity, an increase in invertebrate drift and loss of the most sensitive taxa. The findings indicate that short-term salinity increases have a significant impact on the stream invertebrate community, but concentrations of 5 mS cm −1 are needed to produce a significant ecological response. - Highlights: ► Short-term salinization has a significant impact on the aquatic invertebrates. ► A significant short-term ecological response is registered at 5 mS cm −1 . ► Salinization causes a decline in invertebrate density, richness and diversity. ► Biotic quality indices decline with increasing salinity and exposure time. - Short-term salinization in a stream mesocosm caused a significant response in the aquatic invertebrate community and led to declines in biological quality indices.

  14. 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)

  15. Effect of mesohabitats on responses of invertebrate community structure in streams under different land uses.

    Science.gov (United States)

    da Silva, Marcos Vinícius Dias; Rosa, Beatriz F J V; Alves, Roberto G

    2015-11-01

    Riparian vegetation is one of the most important abiotic components determining the water flow pattern in lotic ecosystems, influencing the composition, richness, and diversity of invertebrates. We have identified whether differences in the structure of the assemblages of invertebrates between riffles and pools may influence the responses of fauna to the effects of land use. In addition, we investigated which fauna metrics are responsible for the differentiation between riffles and pools in streams subject to different land uses. During the dry season of 2012, the main substrates of riffles and pools were sampled (Surber collector) from nine streams within forest, pasture, and urban areas. Principal component analysis (PCA) and Permanova showed differences in the set of environmental variables between streams and mesohabitats. The first PCA axis distinguished the forest and pasture streams from the urban area streams and was related to variables indicative of nutrient enrichment and land use, while the second axis was formed by velocity flow and by the quantities of ultrafine and coarse sand, which distinguished the riffles and pools of the streams. The faunal composition distinguished the streams in pasture and forest areas from the urban streams. Riffles and pools were not concordant in the representation of the invertebrate fauna, indicating the importance of sampling both mesohabitats in the types of streams investigated. The richness, taxonomic composition, and relative abundance of families of Ephemeroptera, Plecoptera, and Trichoptera showed robust responses in riffles to the effects of environmental changes, while in pools, only the richness showed a significant response. It was possibly concluded that riffles were more sensitive in detecting the effects of land use. The information from this study help to understand how the community of invertebrates and the types of habitats in streams may be affected by anthropogenic impacts.

  16. Macrophytes, epipelic biofilm, and invertebrates as biotic indicators of physical habitat degradation of lowland streams (Argentina).

    Science.gov (United States)

    Cortelezzi, Agustina; Sierra, María Victoria; Gómez, Nora; Marinelli, Claudia; Rodrigues Capítulo, Alberto

    2013-07-01

    Our objective was to assess the effect of the physical habitat degradation in three lowland streams of Argentina that are subject to different land uses. To address this matter, we looked into some physical habitat alterations, mainly the water quality and channel changes, the impact on macrophytes' community, and the structural and functional descriptors of the epipelic biofilm and invertebrate assemblages. As a consequence of physical and chemical perturbations, we differentiated sampling sites with different degradation levels. The low degraded sites were affected mainly for the suburban land use, the moderately degraded sites for the rural land use, and the highly degraded sites for the urban land use. The data shows that the biotic descriptors that best reflected the environmental degradation were vegetation cover and macrophytes richness, the dominance of tolerant species (epipelic biofilm and invertebrates), algal biomass, O2 consumption by the epipelic biofilm, and invertebrates' richness and diversity. Furthermore, the results obtained highlight the importance of the macrophytes in the lowland streams, where there is a poor diversification of abiotic substrates and where the macrophytes not only provide shelter but also a food source for invertebrates and other trophic levels such as fish. We also noted that both in benthic communities, invertebrates and epipelic biofilm supplied different information: the habitat's physical structure provided by the macrophytes influenced mainly the invertebrate descriptors; meanwhile, the water quality mainly influenced most of the epipelic biofilm descriptors.

  17. Downstream changes in spring-fed stream invertebrate communities: the effect of increased temperature range?

    Directory of Open Access Journals (Sweden)

    Russell G. DEATH

    2011-09-01

    Full Text Available Reduced thermal amplitude has been highlighted as a limiting factor for aquatic invertebrate diversity in springs. Moving downstream water temperature range increases and invertebrate richness is expected to change accordingly. In the present study temperature patterns were investigated in seven spring-fed streams, between April 2001 and November 2002, and compared to five run-off-fed streams to assess the degree of crenic temperature constancy. Temperature and physico-chemical characteristics of the water, and food resource levels were measured, and the invertebrate fauna collected at 4 distances (0, 100, 500 m and 1 km from seven springs in the North and South Islands of New Zealand. Temperature variability was greater for run-off-fed streams than for springs, and increased in the spring-fed streams with distance from the source. Periphyton and physico-chemical characteristics of the water did not change markedly over the 1 km studied, with the exception of water velocity and organic matter biomass, which increased and decreased, respectively. The rate of increase in temperature amplitude differed greatly for the studied springs, probably being affected by flow, altitude, and the number and type of tributaries (i.e., spring- or run-off-fed joining the spring-fed stream channel. Longitudinal changes in the number and evenness of invertebrate taxa were positively correlated to thermal amplitude (rs = 0.8. Moving downstream, invertebrate communities progressively incorporated taxa with higher mobility and taxa more common in nearby run-off-fed streams. Chironomids and non-insect taxa were denser at the sources. Chironomid larvae also numerically dominated communities 100 and 500 m downstream from the sources, together with Pycnocentria spp. and Zelolessica spp., while taxa such as Hydora sp. and Hydraenidae beetles, the mayflies Deleatidium spp. and Coloburiscus humeralis, and the Trichoptera Pycnocentrodes spp., all had greater abundances 1 km

  18. Monitoring changes in stream bottom sediments and benthic invertebrates.

    Science.gov (United States)

    1981-01-01

    The study was conducted to determine whether the analysis of stream bottom sediments could be used to assess sediment pollution generated by highway construction. Most of the work completed to date has involved testing and refining methods for the co...

  19. Do Riparian Buffers Protect Stream Invertebrate Communities in South American Atlantic Forest Agricultural Areas?

    Science.gov (United States)

    Hunt, L.; Marrochi, N.; Bonetto, C.; Liess, M.; Buss, D. F.; Vieira da Silva, C.; Chiu, M.-C.; Resh, V. H.

    2017-12-01

    We investigated the influence and relative importance of insecticides and other agricultural stressors in determining variability in invertebrate communities in small streams in intensive soy-production regions of Brazil and Paraguay. In Paraguay we sampled 17 sites on tributaries of the Pirapó River in the state of Itapúa and in Brazil we sampled 18 sites on tributaries of the San Francisco River in the state of Paraná. The riparian buffer zones generally contained native Atlantic forest remnants and/or introduced tree species at various stages of growth. In Brazil the stream buffer width was negatively correlated with sediment insecticide concentrations and buffer width was found to have moderate importance in mitigating effects on some sensitive taxa such as mayflies. However, in both regions insecticides had low relative importance in explaining variability in invertebrate communities, while various habitat parameters were more important. In Brazil, the percent coverage of soft depositional sediment in streams was the most important agriculture-related explanatory variable, and the overall stream-habitat score was the most important variable in Paraguay streams. Paraguay and Brazil both have laws requiring forested riparian buffers. The ample forested riparian buffer zones typical of streams in these regions are likely to have mitigated the effects of pesticides on stream invertebrate communities. This study provides evidence that riparian buffer regulations in the Atlantic Forest region are protecting stream ecosystems from pesticides and other agricultural stressors. Further studies are needed to determine the minimum buffer widths necessary to achieve optimal protection.

  20. Bright lights, big city: influences of ecological light pollution on reciprocal stream-riparian invertebrate fluxes.

    Science.gov (United States)

    Meyer, Lars A; Sullivan, S Mazeika P

    2013-09-01

    Cities produce considerable ecological light pollution (ELP), yet the effects of artificial night lighting on biological communities and ecosystem function have not been fully explored. From June 2010 to June 2011, we surveyed aquatic emergent insects, riparian arthropods entering the water, and riparian spiders of the family Tetragnathidae at nine stream reaches representing common ambient ELP levels of Columbus, Ohio, USA, streams (low, 0.1-0.5 lux; moderate, 0.6-2.0 lux; high, 2.1-4.0 lux). In August 2011, we experimentally increased light levels at the low- and moderate-treatment reaches to 10-12 lux to represent urban streams exposed to extremely high levels of ELP. Although season exerted the dominant influence on invertebrate fluxes over the course of the year, when analyzed by season, we found that light strongly influenced multiple invertebrate responses. The experimental light addition resulted in a 44% decrease in tetragnathid spider density (P = 0.035), decreases of 16% in family richness (P = 0.040) and 76% in mean body size (P = 0.022) of aquatic emergent insects, and a 309% increase in mean body size of terrestrial arthropods (P = 0.015). Our results provide evidence that artificial light sources can alter community structure and ecosystem function in streams via changes in reciprocal aquatic-terrestrial fluxes of invertebrates.

  1. Metal toxicity affects predatory stream invertebrates less than other functional feeding groups

    International Nuclear Information System (INIS)

    Liess, Matthias; Gerner, Nadine V.; Kefford, Ben J.

    2017-01-01

    Ecosystem effects of heavy metals need to be identified for a retrospective risk assessment, and potential impacts need to be predicted for a prospective risk assessment. In this study, we established a strong correlation between the toxic pressure of dissolved metals and invertebrate species. We compiled available data from a wide geographical range of Australian streams that were contaminated with heavy metals [mainly copper (Cu) and zinc (Zn)] and the corresponding invertebrate communities. Heavy metal toxicity is positively related to the proportion of predators within the invertebrate community, represented by the predator ratio , with an effect threshold range of 2.6 μg/L - 26 μg/L for Cu and 62 μg/L - 617 μg/L for Zn. These effect concentrations are in the ranges of the concentrations identified in model ecosystems and other field investigations and are just above the existing guideline limits. Heavy metals also affects the taxa richness negatively. Other community measures, such as the evenness, number of EPT (Ephemeroptera, Plecoptera, and Trichoptera) taxa, SPEcies At Risk (SPEAR) pesticides or SPEAR salinity were relatively poorly correlated with heavy metal toxicity in the streams. Therefore, we suggest applying the predator ratio within the community as a starting point for an indicator of the dissolved metal toxicity, the SPEAR metals . - Highlights: • Data on dissolved metals and invertebrates were compiled for a wide geographical range. • Heavy metal toxicity was strongly related to the predator ratio. • Ecologically relevant thresholds identified for Cu and Zn were above the guideline limits. - Increasing metal toxicity for Cu and Zn in streams could be related to an increasing predator ratio within the invertebrate community.

  2. Ecoregion and land-use influence invertebrate and detritus transport from headwater streams

    Science.gov (United States)

    Binckley, Christopher A.; Wipfli, Mark S.; Medhurst, R. Bruce; Polivka, Karl; Hessburg, Paul F.; Salter, R. Brion; Kill, Joshua Y.

    2010-01-01

    Summary 1. Habitats are often connected by fluxes of energy and nutrients across their boundaries. For example, headwater streams are linked to surrounding riparian vegetation through invertebrate and leaf litter inputs, and there is evidence that consumers in downstream habitats are subsidised by resources flowing from headwater systems. However, the strength of these linkages and the manner in which potential headwater subsidies vary along climatic and disturbance gradients are unknown.

  3. Evaluation of stream ecological integrity using litter decomposition and benthic invertebrates

    Energy Technology Data Exchange (ETDEWEB)

    Castela, Jose [Departamento de Zoologia and IMAR-CIC, Universidade de Coimbra, Largo Marques de Pombal, 3004-517 Coimbra (Portugal)], E-mail: jcccastela@gmail.com; Ferreira, Veronica [Departamento de Zoologia and IMAR-CIC, Universidade de Coimbra, Largo Marques de Pombal, 3004-517 Coimbra (Portugal)], E-mail: veronica@ci.uc.pt; Graca, Manuel A.S. [Departamento de Zoologia and IMAR-CIC, Universidade de Coimbra, Largo Marques de Pombal, 3004-517 Coimbra (Portugal)], E-mail: mgraca@ci.uc.pt

    2008-05-15

    Biomonitoring programs to access the ecological integrity of freshwaters tend to rely exclusively on structural parameters. Here we evaluated stream ecological integrity using (a) benthic macroinvertebrate derived metrics and a biotic index as measures of structural integrity and (b) oak litter decomposition and associated fungal sporulation rates as measures of functional integrity. The study was done at four sites (S1, S2, S3 and S4) along a downstream increasing phosphorus and habitat degradation gradient in a small stream. The biotic index, invertebrate metrics, invertebrate and fungal communities' structure and sporulation rates discriminated upstream and downstream sites. Decomposition rates classified sites S4 and S2 as having a compromised ecosystem functioning. Although both functional and structural approaches gave the same results for the most impacted site (S4), they were complementary for moderately impacted sites (S2 and S3), and we therefore support the need for incorporating functional measures in evaluations of stream ecological integrity. - This study supports the need for incorporating functional measures in evaluations of stream ecological integrity.

  4. Evaluation of stream ecological integrity using litter decomposition and benthic invertebrates

    International Nuclear Information System (INIS)

    Castela, Jose; Ferreira, Veronica; Graca, Manuel A.S.

    2008-01-01

    Biomonitoring programs to access the ecological integrity of freshwaters tend to rely exclusively on structural parameters. Here we evaluated stream ecological integrity using (a) benthic macroinvertebrate derived metrics and a biotic index as measures of structural integrity and (b) oak litter decomposition and associated fungal sporulation rates as measures of functional integrity. The study was done at four sites (S1, S2, S3 and S4) along a downstream increasing phosphorus and habitat degradation gradient in a small stream. The biotic index, invertebrate metrics, invertebrate and fungal communities' structure and sporulation rates discriminated upstream and downstream sites. Decomposition rates classified sites S4 and S2 as having a compromised ecosystem functioning. Although both functional and structural approaches gave the same results for the most impacted site (S4), they were complementary for moderately impacted sites (S2 and S3), and we therefore support the need for incorporating functional measures in evaluations of stream ecological integrity. - This study supports the need for incorporating functional measures in evaluations of stream ecological integrity

  5. Experimental manipulation of leaf litter colonization by aquatic invertebrates in a third order tropical stream.

    Science.gov (United States)

    Uieda, V S; Carvalho, E M

    2015-05-01

    Through a manipulative experiment, the colonization of leaf litter by invertebrates was investigated in two sections of a tropical stream (spatial scale) that differed in function of the canopy cover, one with the presence (closed area) and another without riparian vegetation (open area), during one month of the dry and one of the wet season (temporal scale). The work aimed to verify differences related to four variables: season, canopy cover, leaf type and leaf condition. Litter bags containing arboreal and herbaceous leaves (leaf type variable), non-conditioned and preconditioned (leaf condition variable) were placed at the bottom of the stream in each area (canopy cover variable) and season (dry and wet), and removed after 13-day colonization. The analysis of the remaining litter dry mass per leaf bag emphasizes differences related mainly to seasonality, canopy cover and leaf type, although leaf condition was also important when combined with those three factors. Comparing the abundance of invertebrates per treatment, there was a tendency of high predominance of Chironomidae during the dry season and greater taxa diversity and evenness during the wet season, when the water flow increase could alter the availability of microhabitats for local fauna. Even though canopy cover alone was not a significant source of variation in the abundance of invertebrates, the results showed a tendency of a combined effect of canopy cover with seasonality and leaf condition.

  6. A mesocosm approach for detecting stream invertebrate community responses to treated wastewater effluent

    International Nuclear Information System (INIS)

    Grantham, Theodore E.; Cañedo-Argüelles, Miguel; Perrée, Isabelle; Rieradevall, Maria; Prat, Narcís

    2012-01-01

    The discharge of wastewater from sewage treatment plants is one of the most common forms of pollution to river ecosystems, yet the effects on aquatic invertebrate assemblages have not been investigated in a controlled experimental setting. Here, we use a mesocosm approach to evaluate community responses to exposure to different concentrations of treated wastewater effluents over a two week period. Multivariate analysis using Principal Response Curves indicated a clear, dose-effect response to the treatments, with significant changes in macroinvertebrate assemblages after one week when exposed to 30% effluent, and after two weeks in the 15% and 30% effluent treatments. Treatments were associated with an increase in nutrient concentrations (ammonium, sulfate, and phosphate) and reduction of dissolved oxygen. These findings indicate that exposure to wastewater effluent cause significant changes in abundance and composition of macroinvertebrate taxa and that effluent concentration as low as 5% can have detectable ecological effects. - Highlights: ► Stream invertebrate communities are altered by exposure to wastewater effluent. ► Principal Response Curves indicate a dose-effect response to effluent treatment. ► Biotic quality indices decline with increasing effluent concentration and exposure time. ► Effluent concentrations as low as 5% have detectable ecological effects. - Exposure to treated effluent in a stream mesocosm caused a dose-dependent response in the aquatic invertebrate community and led to declines in biological quality indices.

  7. Invertebrate composition and abundance associated with Didymosphenia geminata in a montane stream

    Science.gov (United States)

    James, Daniel A.; Ranney, Steven H.; Chipps, Steven R.; Spindler, Bryan D.

    2010-01-01

    Didymosphenia geminata, a relatively new aquatic nuisance species that can form extensive, mucilaginous mats on stream substrates, was reported from Rapid Creek, South Dakota in 2002. To examine the association between D. geminata and the invertebrate community in Rapid Creek, macroinvertebrates were quantified using three gear types in the fall of 2006. D. geminata was present at two of four sites sampled (range = 5.53 to 809.68 g m−2 dry mass). At each site, invertebrates were collected using dip nets, Surber samplers, and drift nets. The combined percentage of Ephemeroptera, Plecoptera, and Trichoptera in areas with D. geminata was lower (41%) than in areas without D. geminata (76%). Diptera abundance was higher at sites with D. geminata than in sites where D. geminata was absent.

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

    International Nuclear Information System (INIS)

    Pestana, J.L.T.; Alexander, A.C.; Culp, J.M.; Baird, D.J.; Cessna, A.J.; Soares, A.M.V.M.

    2009-01-01

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

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

    Energy Technology Data Exchange (ETDEWEB)

    Pestana, J.L.T., E-mail: jpestana@ua.p [CESAM and Departamento de Biologia, Universidade de Aveiro, Campus Universitario de Santiago, 3810-193 Aveiro (Portugal); Environment Canada at Canadian Rivers Institute, Department of Biology, University of New Brunswick, 10 Bailey Drive, Fredericton, NB (Canada); Alexander, A.C., E-mail: alexa.alexander@unb.c [Environment Canada at Canadian Rivers Institute, Department of Biology, University of New Brunswick, 10 Bailey Drive, Fredericton, NB (Canada); Culp, J.M., E-mail: jculp@unb.c [Environment Canada at Canadian Rivers Institute, Department of Biology, University of New Brunswick, 10 Bailey Drive, Fredericton, NB (Canada); Baird, D.J., E-mail: djbaird@unb.c [Environment Canada at Canadian Rivers Institute, Department of Biology, University of New Brunswick, 10 Bailey Drive, Fredericton, NB (Canada); Cessna, A.J., E-mail: asoares@ua.p [Environment Canada, National Hydrology Research Centre, 11 Innovation Boulevard, Saskatoon, SK (Canada); Soares, A.M.V.M., E-mail: asoares@ua.p [CESAM and Departamento de Biologia, Universidade de Aveiro, Campus Universitario de Santiago, 3810-193 Aveiro (Portugal)

    2009-08-15

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

  10. Effects of coal mining, forestry, and road construction on southern Appalachian stream invertebrates and habitats.

    Science.gov (United States)

    Gangloff, Michael M; Perkins, Michael; Blum, Peter W; Walker, Craig

    2015-03-01

    Coal has been extracted via surface and sub-surface mining for decades throughout the Appalachian Mountains. New interest in ridge-top mining has raised concerns about possible waterway impacts. We examined effects of forestry, mining, and road construction-based disturbance on physico-chemistry and macroinvertebrate communities in east-central Tennessee headwater streams. Although 11 of 30 sites failed Tennessee's biocriteria scoring system, invertebrate richness was moderately high and we did not find significant differences in any water chemistry or habitat parameters between sites with passing and failing scores. However, conductivity and dissolved solid concentrations appeared elevated in the majority of study streams. Principal components (PCs) analysis indicated that six PCs accounted for ~77 % of among-site habitat variability. One PC associated with dissolved oxygen and specific conductance explained the second highest proportion of among-site variability after catchment area. Specific conductance was not correlated with catchment area but was strongly correlated with mining activity. Composition and success of multivariate models using habitat PCs to predict macroinvertebrate metrics was highly variable. PC scores associated with water chemistry and substrate composition were most frequently included in significant models. These results suggest that impacts of historical and current coal mining remain a source of water quality and macroinvertebrate community impairment in this region, but effects are subtle. Our results suggest that surface mining may have chronic and system-wide effects on habitat conditions and invertebrate communities in Cumberland Plateau streams.

  11. Untangling the relationships among regional occupancy, species traits, and niche characteristics in stream invertebrates

    Science.gov (United States)

    Heino, Jani; Grönroos, Mira

    2014-01-01

    The regional occupancy and local abundance of species are affected by various species traits, but their relative effects are poorly understood. We studied the relationships between species traits and occupancy (i.e., proportion of sites occupied) or abundance (i.e., mean local abundance at occupied sites) of stream invertebrates using small-grained data (i.e., local stream sites) across a large spatial extent (i.e., three drainage basins). We found a significant, yet rather weak, linear relationship between occupancy and abundance. However, occupancy was strongly related to niche position (NP), but it showed a weaker relationship with niche breadth (NB). Abundance was at best weakly related to these explanatory niche-based variables. Biological traits, including feeding modes, habit traits, dispersal modes and body size classes, were generally less important in accounting for variation in occupancy and abundance. Our findings showed that the regional occupancy of stream invertebrate species is mostly related to niche characteristics, in particular, NP. However, the effects of NB on occupancy were affected by the measure itself. We conclude that niche characteristics determine the regional occupancy of species at relatively large spatial extents, suggesting that species distributions are determined by environmental variation among sites. PMID:24963387

  12. Methylmercury bioaccumulation in invertebrates of boreal streams in Norway: Effects of aqueous methylmercury and diet retention

    International Nuclear Information System (INIS)

    Wit, Heleen A. de; Kainz, Martin J.; Lindholm, Markus

    2012-01-01

    Transfer of aqueous methylmercury (MeHg) to primary consumers in aquatic foodwebs is poorly understood despite its importance for bioaccumulation of MeHg. We studied bioaccumulation of MeHg in simple aquatic food chains of two humic boreal streams in relation to streamwater chemistry, food web characteristics and dietary fatty acid (FA) biomarkers. Transfer of aqueous MeHg into primary consumers was similar in both streams, resulting in higher MeHg in consumers in the MeHg-rich stream. Trophic enrichment of MeHg and dietary retention of FA biomarkers was the same in both streams, suggesting that exposure to aqueous MeHg at the base of the food chain determined levels of MeHg in biota. In addition, contents of dietary biomarkers suggested that ingestion of algae reduced MeHg bioaccumulation, while ingestion of bacteria stimulated MeHg uptake. Dietary uptake of bacteria could thus be an important pathway for MeHg-transfer at the bottom of food chains in humic streams. - Highlights: ► We examined MeHg bioaccumulation in simple food chains in two boreal streams. ► Higher MeHg in invertebrates was associated with higher aqueous MeHg. ► Dietary biomarkers showed that consumers in both streams accessed similar food sources. ► We concluded at exposure to aqueous MeHg determined bioaccumulation of MeHg. ► Seasonal variation in MeHg in biota could be related to diet using dietary biomarkers. - Exposure to aqueous methylmercury at the base of the food chain in boreal streams determines mercury in aquatic biota at higher trophic levels.

  13. Hyporheic invertebrate assemblages at reach scale in a Neotropical stream in Brazil.

    Science.gov (United States)

    Mugnai, R; Messana, G; Di Lorenzo, T

    2015-11-01

    In the Neotropical Region, information concerning hyporheic communities is virtually non-existent. We carried out a sampling survey in the hyporheic zone of the Tijuca River, in the Tijuca National Park, located in the urban area of the city of Rio de Janeiro. Biological samples from the hyporheic zone were collected in three different stream reaches, in June 2012. The main objectives were: 1) to describe the structure of invertebrate assemblages in the hyporheic zone of a neotropical stream; 2) to apply a reach-scale approach in order to investigate spatial patterns of the hyporheic assemblages in relation to hydrology, depth and microhabitat typology. A total of 1460 individuals were collected and identified in 31 taxa belonging to Nematoda, Annelida, Crustacea, Hydrachnidia and Insecta. The class Insecta dominated the upper layer of the hyporheic zone. Copepods were the most abundant taxon among crustaceans and occurred mostly in the upwelling areas of the reaches. The results of this study represent one of the few contributions so far about hyporheic invertebrate assemblages of the Neotropical Region.

  14. Leaf litter processing and invertebrate assemblages along a pollution gradient in a Maine (USA) headwater stream

    International Nuclear Information System (INIS)

    Woodcock, Thomas S.; Huryn, Alexander D.

    2005-01-01

    During the autumn of 1997 and 1998, leaf litter processing rates and leaf pack invertebrate assemblages were examined at eight stations along a pollution gradient in Goosefare Brook, a first-order coastal plain stream in southern Maine (USA). There was no significant effect on litter softening rate in 1997, and only the most polluted station showed a decrease in 1998. However, litter loss rates showed decreases in both years. The structure of invertebrate assemblages changed in response to the stresses, showing a decline in EPT richness and an increase in the proportion of collecting taxa. However, total shredder biomass was only weakly affected. Shredder biomass at all stations was dominated by Tipula, and biomass of other shredder taxa showed a serial replacement along the gradient of stress related to their pollution tolerance. Rather than the expected relationship with shredder biomass, litter processing rates were directly related to water and sediment quality. Goosefare Brook demonstrates how variable pollution tolerance of community members enables stress resistance and a consequent preservation of ecosystem function. - Variable pollution tolerance of community members provides stress resistance at the ecosystem level in streams

  15. Bridging the gap between theoretical ecology and real ecosystems: modeling invertebrate community composition in streams.

    Science.gov (United States)

    Schuwirth, Nele; Reichert, Peter

    2013-02-01

    For the first time, we combine concepts of theoretical food web modeling, the metabolic theory of ecology, and ecological stoichiometry with the use of functional trait databases to predict the coexistence of invertebrate taxa in streams. We developed a mechanistic model that describes growth, death, and respiration of different taxa dependent on various environmental influence factors to estimate survival or extinction. Parameter and input uncertainty is propagated to model results. Such a model is needed to test our current quantitative understanding of ecosystem structure and function and to predict effects of anthropogenic impacts and restoration efforts. The model was tested using macroinvertebrate monitoring data from a catchment of the Swiss Plateau. Even without fitting model parameters, the model is able to represent key patterns of the coexistence structure of invertebrates at sites varying in external conditions (litter input, shading, water quality). This confirms the suitability of the model concept. More comprehensive testing and resulting model adaptations will further increase the predictive accuracy of the model.

  16. Understanding the effects of predictability, duration, and spatial pattern of drying on benthic invertebrate assemblages in two contrasting intermittent streams

    Science.gov (United States)

    von Schiller, Daniel; Barberá, Gonzalo G.; Díaz, Angela M.; Arce, Maria Isabel; del Campo, Rubén; Tockner, Klement

    2018-01-01

    In the present study, we examined the effects of different drying conditions on the composition, structure and function of benthic invertebrate assemblages. We approached this objective by comparing invertebrate assemblages in perennial and intermittent sites along two intermittent Mediterranean streams with contrasting predictability, duration, and spatial patterns of drying: Fuirosos (high predictability, short duration, downstream drying pattern) and Rogativa (low predictability, long duration, patchy drying pattern). Specifically, we quantified the contribution of individual taxa to those differences, the degree of nestedness, and shifts in the composition, structure and function of benthic invertebrate assemblages along flow intermittence gradients. We observed greater effects of drying on the benthic invertebrate composition in Fuirosos than in Rogativa, resulting in a higher dissimilarity of assemblages between perennial and intermittent sites, as well as a lower degree of nestedness. Furthermore, a higher number of biotic metrics related to richness, abundance and biological traits were significantly different between perennial and intermittent sites in Fuirosos, despite a shorter dry period compared to Rogativa. At the same time, slightly different responses were detected during post-drying (autumn) than pre-drying (spring) conditions in this stream. In Rogativa, shifts in benthic invertebrate assemblages along increasing gradients of flow intermittence were found for three metrics (Ephemeroptera, Plecoptera and Trichoptera (EPT) and Odonata, Coleoptera and Heteroptera (OCH) abundances and aerial active dispersal. Furthermore, we demonstrated that combined gradients of dry period duration and distance to nearest perennial reach can generate complex, and different, responses of benthic invertebrate assemblages, depending on the flow intermittence metric. Our study advances the notion that special attention should be paid to the predictability, duration and

  17. 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...

  18. The Effects of Agricultural Land-use on Stream Fish and Invertebrate Communities and Food-web Structure.

    Science.gov (United States)

    North, C. A.; Fischer, R. U.

    2005-05-01

    Incorporating knowledge of the surrounding landscape can further the understanding of stream processes. This is particularly true in areas like the Midwest where human alteration of the landscape, such as conversion of natural cover types into cultivated row crops, is widespread. When assessing stream health, the composition and structure of biological communities themselves often are the best indicators of water quality. Previous work in Hurricane Creek (Coles and Cumberland Counties, IL) demonstrated significant differences in water chemistry and community metabolism between sites subject to differing intensities of farming in the upstream watershed. Our objective was to examine differences in fish and invertebrate communities at four sites along the stream representing varying degrees of agricultural land-use. Fish were sampled using electroseining techniques and invertebrates were collected using the 20-jab method in each of four seasons. Sites were compared using fish and invertebrate community metrics, including indices of biotic integrity (IBI, MBI). Stable isotope analyses were also performed to quantify differences in food-web structure in streams draining watersheds characterized by different degrees of agricultural land-use. This study improves understanding of how landscape alteration impacts stream biota and will facilitate more informed decisions concerning stream rehabilitation.

  19. Using propensity scores to estimate the effects of insecticides on stream invertebrates from observational data

    Science.gov (United States)

    Lester L. Yuan,; Amina I. Pollard,; Carlisle, Daren M.

    2009-01-01

    Analyses of observational data can provide insights into relationships between environmental conditions and biological responses across a broader range of natural conditions than experimental studies, potentially complementing insights gained from experiments. However, observational data must be analyzed carefully to minimize the likelihood that confounding variables bias observed relationships. Propensity scores provide a robust approach for controlling for the effects of measured confounding variables when analyzing observational data. Here, we use propensity scores to estimate changes in mean invertebrate taxon richness in streams that have experienced insecticide concentrations that exceed aquatic life use benchmark concentrations. A simple comparison of richness in sites exposed to elevated insecticides with those that were not exposed suggests that exposed sites had on average 6.8 fewer taxa compared to unexposed sites. The presence of potential confounding variables makes it difficult to assert a causal relationship from this simple comparison. After controlling for confounding factors using propensity scores, the difference in richness between exposed and unexposed sites was reduced to 4.1 taxa, a difference that was still statistically significant. Because the propensity score analysis controlled for the effects of a wide variety of possible confounding variables, we infer that the change in richness observed in the propensity score analysis was likely caused by insecticide exposure.

  20. Pond and Stream Safari: A Guide to the Ecology of Aquatic Invertebrates.

    Science.gov (United States)

    Edelstein, Karen

    This packet includes a leader's guide, a quick reference guide to aquatic invertebrates, a checklist of common aquatic invertebrates, and activity sheets. The leader's guide includes four sections on background information and seven activities. Background sections include: Understanding Aquatic Insects; Growing Up: Aquatic Insect Forms; Adapting…

  1. Streamflow characteristics and benthic invertebrate assemblages in streams across the western United States

    Science.gov (United States)

    Brasher, Anne M.D.; Konrad, Chris P.; May, Jason T.; Edmiston, C. Scott; Close, Rebecca N.

    2010-01-01

    Hydrographic characteristics of streamflow, such as high-flow pulses, base flow (background discharge between floods), extreme low flows, and floods, significantly influence aquatic organisms. Streamflow can be described in terms of magnitude, timing, duration, frequency, and variation (hydrologic regime). These characteristics have broad effects on ecosystem productivity, habitat structure, and ultimately on resident fish, invertebrate, and algae communities. Increasing human use of limited water resources has modified hydrologic regimes worldwide. Identifying the most ecologically significant hydrographic characteristics would facilitate the development of water-management strategies.Benthic invertebrates include insects, mollusks (snails and clams), worms, and crustaceans (shrimp) that live on the streambed. Invertebrates play an important role in the food web, consuming other invertebrates and algae and being consumed by fish and birds. Hydrologic alteration associated with land and water use can change the natural hydrologic regime and may affect benthic invertebrate assemblage composition and structure through changes in density of invertebrates or taxa richness (number of different species).This study examined associations between the hydrologic regime and characteristics of benthic invertebrate assemblages across the western United States and developed tools to identify streamflow characteristics that are likely to affect benthic invertebrate assemblages.

  2. The effects of run-of-river hydroelectric power schemes on invertebrate community composition in temperate streams and rivers.

    Science.gov (United States)

    Bilotta, Gary S; Burnside, Niall G; Turley, Matthew D; Gray, Jeremy C; Orr, Harriet G

    2017-01-01

    Run-of-river (ROR) hydroelectric power (HEP) schemes are often presumed to be less ecologically damaging than large-scale storage HEP schemes. However, there is currently limited scientific evidence on their ecological impact. The aim of this article is to investigate the effects of ROR HEP schemes on communities of invertebrates in temperate streams and rivers, using a multi-site Before-After, Control-Impact (BACI) study design. The study makes use of routine environmental surveillance data collected as part of long-term national and international monitoring programmes at 22 systematically-selected ROR HEP schemes and 22 systematically-selected paired control sites. Five widely-used family-level invertebrate metrics (richness, evenness, LIFE, E-PSI, WHPT) were analysed using a linear mixed effects model. The analyses showed that there was a statistically significant effect (p<0.05) of ROR HEP construction and operation on the evenness of the invertebrate community. However, no statistically significant effects were detected on the four other metrics of community composition. The implications of these findings are discussed in this article and recommendations are made for best-practice study design for future invertebrate community impact studies.

  3. Interactive effects of an insecticide and a fungicide on different organism groups and ecosystem functioning in a stream detrital food web.

    Science.gov (United States)

    Dawoud, Mohab; Bundschuh, Mirco; Goedkoop, Willem; McKie, Brendan G

    2017-05-01

    Freshwater ecosystems are often affected by cocktails of multiple pesticides targeting different organism groups. Prediction and evaluation of the ecosystem-level effects of these mixtures is complicated by the potential not only for interactions among the pesticides themselves, but also for the pesticides to alter biotic interactions across trophic levels. In a stream microcosm experiment, we investigated the effects of two pesticides targeting two organism groups (the insecticide lindane and fungicide azoxystrobin) on the functioning of a model stream detrital food web consisting of a detritivore (Ispoda: Asellus aquaticus) and microbes (an assemblage of fungal hyphomycetes) consuming leaf litter. We assessed how these pesticides interacted with the presence and absence of the detritivore to affect three indicators of ecosystem functioning - leaf decomposition, fungal biomass, fungal sporulation - as well as detritivore mortality. Leaf decomposition rates were more strongly impacted by the fungicide than the insecticide, reflecting especially negative effects on leaf processing by detritivores. This result most like reflects reduced fungal biomass and increased detritivore mortality under the fungicide treatment. Fungal sporulation was elevated by exposure to both the insecticide and fungicide, possibly representing a stress-induced increase in investment in propagule dispersal. Stressor interactions were apparent in the impacts of the combined pesticide treatment on fungal sporulation and detritivore mortality, which were reduced and elevated relative to the single stressor treatments, respectively. These results demonstrate the potential of trophic and multiple stressor interactions to modulate the ecosystem-level impacts of chemicals, highlighting important challenges in predicting, understanding and evaluating the impacts of multiple chemical stressors on more complex food webs in situ. Copyright © 2017 Elsevier B.V. All rights reserved.

  4. Persistent effects of wildfire and debris flows on the invertebrate prey base of rainbow trout in Idaho streams

    Science.gov (United States)

    Rosenberger, A.E.; Dunham, J.B.; Buffington, J.M.; Wipfli, M.S.

    2011-01-01

    Wildfire and debris flows are important physical and ecological drivers in headwater streams of western North America. Past research has primarily examined short-term effects of these disturbances; less is known about longer-term impacts. We investigated wildfire effects on the invertebrate prey base for drift-feeding rainbow trout (Oncorhynchus mykiss, Walbaum) in Idaho headwater streams a decade after wildfire. Three stream types with different disturbance histories were examined: 1) unburned, 2) burned, and 3) burned followed by debris flows that reset channel morphology and riparian vegetation. The quantity of macroinvertebrate drift (biomass density) was more variable within than among disturbance categories. Average body weight and taxonomic richness of drift were significantly related to water temperature and influenced by disturbance history. During the autumn sampling period, the amount of terrestrial insects in rainbow trout diets varied with disturbance history and the amount of overhead canopy along the stream banks. Results indicate that there are detectable changes to macroinvertebrate drift and trout diet a decade after wildfire, and that these responses are better correlated with specific characteristics of the stream (water temperature, canopy cover) than with broad disturbance classes.

  5. Forest-stream linkages: effects of terrestrial invertebrate input and light on diet and growth of brown trout (Salmo trutta in a boreal forest stream.

    Directory of Open Access Journals (Sweden)

    Tibor Erős

    Full Text Available Subsidies of energy and material from the riparian zone have large impacts on recipient stream habitats. Human-induced changes, such as deforestation, may profoundly affect these pathways. However, the strength of individual factors on stream ecosystems is poorly understood since the factors involved often interact in complex ways. We isolated two of these factors, manipulating the flux of terrestrial input and the intensity of light in a 2×2 factorial design, where we followed the growth and diet of two size-classes of brown trout (Salmo trutta and the development of periphyton, grazer macroinvertebrates, terrestrial invertebrate inputs, and drift in twelve 20 m long enclosed stream reaches in a five-month-long experiment in a boreal coniferous forest stream. We found that light intensity, which was artificially increased 2.5 times above ambient levels, had an effect on grazer density, but no detectable effect on chlorophyll a biomass. We also found a seasonal effect on the amount of drift and that the reduction of terrestrial prey input, accomplished by covering enclosures with transparent plastic, had a negative impact on the amount of terrestrial invertebrates in the drift. Further, trout growth was strongly seasonal and followed the same pattern as drift biomass, and the reduction of terrestrial prey input had a negative effect on trout growth. Diet analysis was consistent with growth differences, showing that trout in open enclosures consumed relatively more terrestrial prey in summer than trout living in covered enclosures. We also predicted ontogenetic differences in the diet and growth of old and young trout, where we expected old fish to be more affected by the terrestrial prey reduction, but we found little evidence of ontogenetic differences. Overall, our results showed that reduced terrestrial prey inputs, as would be expected from forest harvesting, shaped differences in the growth and diet of the top predator, brown trout.

  6. Detecting the impact of bank and channel modification on invertebrate communities in Mediterranean temporary streams (Sardinia, SW Italy).

    Science.gov (United States)

    Buffagni, Andrea; Tenchini, Roberta; Cazzola, Marcello; Erba, Stefania; Balestrini, Raffaella; Belfiore, Carlo; Pagnotta, Romano

    2016-09-15

    We hypothesized that reach-scale, bank and channel modification would impact benthic communities in temporary rivers of Sardinia, when pollution and water abstraction are not relevant. A range of variables were considered, which include both artificial structures/alterations and natural features observed in a stream reach. Multivariate regression trees (MRT) were used to assess the effects of the explanatory variables on invertebrate assemblages and five groups, characterized by different habitat modification and/or features, were recognized. Four node variables determined the splits in the MRT analysis: channel reinforcement, tree-related bank and channel habitats, channel modification and bank modification. Continuity of trees in the river corridor diverged among MRT groups and significant differences among groups include presence of alders, extent of channel shading and substrate diversity. Also, the percentage of in-stream organic substrates, in particular CPOM/Xylal, showed highly significant differences among groups. For practical applications, thresholds for the extent of channel reinforcement (40%) and modification (10%) and for bank alteration (≈30%) were provided, that can be used to guide the implementation of restoration measures. In moderately altered river reaches, a significant extent of tree-related habitats (≈5%) can noticeably mitigate the effects of morphological alteration on aquatic invertebrates. The outcomes highlight the importance of riparian zone management as an opportune, achievable prospect in the restoration of Mediterranean temporary streams. The impact of bank and channel modification on ecological status (sensu WFD) was investigated and the tested benthic metrics, especially those based on abundance data, showed legible differences among MRT groups. Finally, bank and channel modification appears to be a potential threat for the conservation of a few Sardo-Corsican endemic species. The introduction of management criteria that

  7. The Influence of Geology and Other Environmental Factors on Stream Water Chemistry and Benthic Invertebrate Assemblages

    OpenAIRE

    Olson, John R.

    2012-01-01

    Catchment geology is known to influence water chemistry, which can significantly affect both species composition and ecosystem processes in streams. However, current predictions of how stream water chemistry varies with geology are limited in both scope and precision, and we have not adequately tested the specific mechanisms by which water chemistry influences stream biota. My dissertation research goals were to (1) develop empirical models to predict natural base-flow water chemistry from ca...

  8. Macro Invertebrates As Bio Indicators Of Water Quality In Nzovwe Stream In Mbeya Tanzania

    Directory of Open Access Journals (Sweden)

    Fredrick Ojija

    2015-08-01

    Full Text Available This study was carried out to assess the water quality of Nzovwe stream using macroinvertebrates as bioindicators. Biological monitoring working party BMWP scoring system was the index used to assess the ecosystem health of Nzovwe stream. A total of 584 aquatic macroinvertebrates were identified from Nzovwe stream. They belonged to 22 families. The most abundant taxa were Odonata 35.959 Hemiptera 25.514 Coleoptera 18.493 and Diptera 12.842. Whereas the least abundant taxa were Ephemeroptera and Gastropoda each constituting 1.028 of all macroinvertebrates. The most abundant macroinvertebrates were Dragonflies 27.226 Water striders 13.185 and Creeping water bugs 10.274 whereas the least abundant were Giant water bugs 0.514 and Backswimmers 0.514. The BMWP score of Nzovwe stream was 115. Based on this score the water of Nzovwe stream is neither very clean nor significantly altered aquatic environment. Hence the Nzovwe stream is moderately polluted due to non-point source pollution from several sources. Moreover it was found that agricultural activities washing and bathing could alter physico-chemical parameters of the stream and hence changing the abundance of macroinvertebrates as well as the quality of water. This study therefore recommends that the source of pollutants should be controlled and the stream regularly monitored by the relevant authorities. Additionally biological indicators and their indices are suggested to be used in assessing the condition of a stream ecosystem.

  9. Effects of a controlled under-ice oil spill on invertebrates of an arctic and a subarctic stream

    Energy Technology Data Exchange (ETDEWEB)

    Miller, M.C.; Stout, J.R.; Alexander, V.

    1986-01-01

    The short-term drift of macroinvertebrates is documented following two controlled oil spills placed under ice in an arctic (Imnavait Creek) and subarctic (Poker-Caribou Creek) stream just as ice covered the water in early winter. No mortality was observed, but several species responded by differentially drifting from the oil-impacted areas during the following days. In the arctic stream, Trichotanypus posticalis (Diptera) showed a significant increase in drift for the first few days. There was also an overall increase in drift of total organisms post spill. Phaenospectra sp. 1, the numerical dominant, decreased its nocturnal drifting compared with the upstream control station in the 5 days post spill. In the subarctic stream, Skwala sp. 1 (Plecoptera), Prosimulium sp. 1 (Simulidae) and Pseudodiamesa sp. 1 showed significant increase din drift post spill. Among the species of benthic invertebrates sampled with a Hess sampler (WILDCO, Saginaw, Mich.), only the density of Nemoura sp. 1 declined significantly post spill. Polar ordinations using percent difference showed that the oil-treated stations separated from the control stations in both the drift and the Hess bottom samples. Colonization of artificial substrates in Imnavait Creek during the winter following the spill was almost non-existent. In Poker-Caribou Creek much colonization took place over the winter with significantly more occurring on unoiled rocks as compared with oiled rocks.

  10. The response of macroinvertebrates to artificially enhanced detritus levels in plantation streams

    Science.gov (United States)

    Pretty, J. L.; Dobson, M.

    The leaves and wood from vegetation surrounding headwater streams constitute a major food source for aquatic invertebrates, providing they are retained upon the streambed and not transported downstream. This study investigated the response of aquatic invertebrates to artificially increased detritus retention, in an effort to reproduce the naturally occurring build up of dead organic matter associated with streams in old-growth forest. The background detrital standing stock in streams in Kielder Forest (Northumberland, UK) was low, approximately 32 gm-2. Two streams flowing through dense conifer plantation and one in open broadleaved woodland were manipulated by the addition of logs over a 10 m stream reach. After several months, log addition significantly enhanced detrital standing stocks in both conifer and broadleaved streams. Total invertebrate abundance, taxon richness and the numbers of certain numerically dominant families were significantly higher in experimental than reference reaches in both conifer and broadleaved streams. This response was most marked for detritivores, whilst non-detritivore groups often showed no response to the manipulation. Whilst in the short term the responses to enhanced retention may reflect a redistribution of the local fauna, it is argued that over a longer time-scale, a genuine increase in invertebrate density and diversity could occur. Allowing old-growth forest to develop in planted valley bottoms may be a viable management option for conservation. If established alongside streams, it would ensure continuous input of woody material and the fauna may benefit from the resulting increase in detritus retention.

  11. Thermal and hydrologic responses to climate change predict marked alterations in boreal stream invertebrate assemblages.

    Science.gov (United States)

    Mustonen, Kaisa-Riikka; Mykrä, Heikki; Marttila, Hannu; Sarremejane, Romain; Veijalainen, Noora; Sippel, Kalle; Muotka, Timo; Hawkins, Charles P

    2018-06-01

    Air temperature at the northernmost latitudes is predicted to increase steeply and precipitation to become more variable by the end of the 21st century, resulting in altered thermal and hydrological regimes. We applied five climate scenarios to predict the future (2070-2100) benthic macroinvertebrate assemblages at 239 near-pristine sites across Finland (ca. 1200 km latitudinal span). We used a multitaxon distribution model with air temperature and modeled daily flow as predictors. As expected, projected air temperature increased the most in northernmost Finland. Predicted taxonomic richness also increased the most in northern Finland, congruent with the predicted northwards shift of many species' distributions. Compositional changes were predicted to be high even without changes in richness, suggesting that species replacement may be the main mechanism causing climate-induced changes in macroinvertebrate assemblages. Northern streams were predicted to lose much of the seasonality of their flow regimes, causing potentially marked changes in stream benthic assemblages. Sites with the highest loss of seasonality were predicted to support future assemblages that deviate most in compositional similarity from the present-day assemblages. Macroinvertebrate assemblages were also predicted to change more in headwaters than in larger streams, as headwaters were particularly sensitive to changes in flow patterns. Our results emphasize the importance of focusing protection and mitigation on headwater streams with high-flow seasonality because of their vulnerability to climate change. © 2018 John Wiley & Sons Ltd.

  12. Hawaii ESI: INVERTPT (Invertebrate Points)

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — This data set contains sensitive biological resource data for native stream invertebrates, anchialine pool invertebrates, and threatened/endangered terrestrial...

  13. Direct and indirect effects of multiple stressors on stream invertebrates across watershed, reach and site scales: A structural equation modelling better informing on hydromorphological impacts.

    Science.gov (United States)

    Villeneuve, B; Piffady, J; Valette, L; Souchon, Y; Usseglio-Polatera, P

    2018-01-15

    The purpose of our approach was to take into account the nested spatial scales driving stream functioning in the description of pressures/ecological status links by analysing the results of a hierarchical model. The development of this model has allowed us to answer the following questions: Does the consideration of the indirect links between anthropogenic pressures and stream ecological status modify the hierarchy of pressure types impacting benthic invertebrates? Do the different nested scales play different roles in the anthropogenic pressures/ecological status relationship? Does this model lead to better understanding of the specific role of hydromorphology in the evaluation of stream ecological status? To achieve that goal, we used the Partial Least Square (PLS) path modelling method to develop a structural model linking variables describing (i) land use and hydromorphological alterations at the watershed scale, (ii) hydromorphological alterations at the reach scale, (iii) nutrients-organic matter contamination levels at the site scale, and (iv) substrate characteristics at the sampling site scale, to explain variation in values of a macroinvertebrate-based multimetric index: the French I 2 M 2 . We have highlighted the importance of land use effects exerted on both hydromorphological and chemical characteristics of streams observed at finer scales and their subsequent indirect impact on stream ecological status. Hydromorphological alterations have an effect on the substrate mosaic structure and on the concentrations of nutrients and organic matter at site scale. This result implies that stream hydromorphology can have a major indirect effect on macroinvertebrate assemblages and that the hierarchy of impacts of anthropogenic pressures on stream ecological status generally described in the literature - often determining strategic restoration priorities - has to be re-examined. Finally, the effects of nutrients and organic matter on macroinvertebrate assemblages

  14. The response of macroinvertebrates to artificially enhanced detritus levels in plantation streams

    Directory of Open Access Journals (Sweden)

    J. L. Pretty

    2004-01-01

    Full Text Available The leaves and wood from vegetation surrounding headwater streams constitute a major food source for aquatic invertebrates, providing they are retained upon the streambed and not transported downstream. This study investigated the response of aquatic invertebrates to artificially increased detritus retention, in an effort to reproduce the naturally occurring build up of dead organic matter associated with streams in old-growth forest. The background detrital standing stock in streams in Kielder Forest (Northumberland, UK was low, approximately 32 gm-2. Two streams flowing through dense conifer plantation and one in open broadleaved woodland were manipulated by the addition of logs over a 10 m stream reach. After several months, log addition significantly enhanced detrital standing stocks in both conifer and broadleaved streams. Total invertebrate abundance, taxon richness and the numbers of certain numerically dominant families were significantly higher in experimental than reference reaches in both conifer and broadleaved streams. This response was most marked for detritivores, whilst non-detritivore groups often showed no response to the manipulation. Whilst in the short term the responses to enhanced retention may reflect a redistribution of the local fauna, it is argued that over a longer time-scale, a genuine increase in invertebrate density and diversity could occur. Allowing old-growth forest to develop in planted valley bottoms may be a viable management option for conservation. If established alongside streams, it would ensure continuous input of woody material and the fauna may benefit from the resulting increase in detritus retention. Keywords: forestry, detritivores, old-growth conifers, river management, woody debris

  15. Development and application of an agricultural intensity index to invertebrate and algal metrics from streams at two scales

    Science.gov (United States)

    Waite, Ian R.

    2013-01-01

    Research was conducted at 28-30 sites within eight study areas across the United States along a gradient of nutrient enrichment/agricultural land use between 2003 and 2007. Objectives were to test the application of an agricultural intensity index (AG-Index) and compare among various invertebrate and algal metrics to determine indicators of nutrient enrichment nationally and within three regions. The agricultural index was based on total nitrogen and phosphorus input to the watershed, percent watershed agriculture, and percent riparian agriculture. Among data sources, agriculture within riparian zone showed significant differences among values generated from remote sensing or from higher resolution orthophotography; median values dropped significantly when estimated by orthophotography. Percent agriculture in the watershed consistently had lower correlations to invertebrate and algal metrics than the developed AG-Index across all regions. Percent agriculture showed fewer pairwise comparisons that were significant than the same comparisons using the AG-Index. Highest correlations to the AG-Index regionally were −0.75 for Ephemeroptera, Plecoptera, and Trichoptera richness (EPTR) and −0.70 for algae Observed/Expected (O/E), nationally the highest was −0.43 for EPTR vs. total nitrogen and −0.62 for algae O/E vs. AG-Index. Results suggest that analysis of metrics at national scale can often detect large differences in disturbance, but more detail and specificity is obtained by analyzing data at regional scales.

  16. Studies on mountain streams in the English lake district I. PH, calcium and the distribution of invertebrates in the River Duddon

    Energy Technology Data Exchange (ETDEWEB)

    Sutcliffe, D.W.; Carrick, T.R.

    1973-01-01

    The River Duddon and its tributaries rarely exceed pH 7.0. There are three types of acid regime; pH>5.7 and pH<5.7 independent of season or rainfall, and fluctuating acidity with pH<5.7 in winter and wet periods, pH>5.7 in summer or dry periods. PH in the River Duddon fluctuates for most of its length. Ph>5.7 is characteristic of tributaries in the lower drainage basin, but pH<5.7 occurs in the headwaters of two of these tributaries. With five exceptions, pH<5.7 or fluctuating pH are characteristic of tributaries in the upper drainage basin. A very close relationship exists between the pH regime of stream water and the benthis cauna. Apart from oligochaetes and flatworms, streams with pH<5.7 or fluctuating pH are characterized by thirteen common or abundant taxa; six plecoptera, four trichoptera and three diptera. These taxa are also common in streams with pH>5.7 but in addition these streams contain ephemeroptera, the trichopterans wormaldia and hydropsyche, the mollusc Ancylus and the amphipod gammarus. It is concluded that the calcium concentration is less important than the pH-bicarbonate concentrations in limiting the qualitative distribution of benthic invertebrates. The limiting effect of pH<5.7 on an extensive range of taxa in the duddon also occurs in other areas. The affected taxa are generally herbivores. It is suggested that in the case of insects the limiting effects of low pH may indirectly operate through changes in food supply.

  17. Hawaii ESI: INVERT (Invertebrate Polygons)

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — This data set contains sensitive biological resource data for marine, estuarine, terrestrial, and native stream invertebrate species in coastal Hawaii. Vector...

  18. Export of detritus and invertebrate from headwater streams: linking mountaintop removal and valley fill coal mining to downstream receiving waters

    Science.gov (United States)

    Mountaintop removal and valley fill (MTR/VF) coal mining has resulted in large scale alteration of the topography, reduced forest productivity, and burial of headwater streams in the U.S. Central Appalachians. Although MTR/VF coal mining has occurred for several decades and the ...

  19. Invertebrate lamins

    International Nuclear Information System (INIS)

    Melcer, Shai; Gruenbaum, Yosef; Krohne, Georg

    2007-01-01

    Lamins are the main component of the nuclear lamina and considered to be the ancestors of all intermediate filament proteins. They are localized mainly at the nuclear periphery where they form protein complexes with integral proteins of the nuclear inner membrane, transcriptional regulators, histones and chromatin modifiers. Studying lamins in invertebrate species has unique advantages including the smaller number of lamin genes in the invertebrate genomes and powerful genetic analyses in Caenorhabditis elegans and Drosophila melanogaster. These simpler nuclear lamina systems allow direct analyses of their structure and functions. Here we give an overview of recent advances in the field of invertebrate nuclear lamins with special emphasis on their evolution, assembly and functions

  20. Invertebrate biomechanics.

    Science.gov (United States)

    Patek, S N; Summers, A P

    2017-05-22

    Invertebrate biomechanics focuses on mechanical analyses of non-vertebrate animals, which at root is no different in aim and technique from vertebrate biomechanics, or for that matter the biomechanics of plants and fungi. But invertebrates are special - they are fabulously diverse in form, habitat, and ecology and manage this without the use of hard, internal skeletons. They are also numerous and, in many cases, tractable in an experimental and field setting. In this Primer, we will probe three axes of invertebrate diversity: worms (Phylum Annelida), spiders (Class Arachnida) and insects (Class Insecta); three habitats: subterranean, terrestrial and airborne; and three integrations with other fields: ecology, engineering and evolution. Our goal is to capture the field of invertebrate biomechanics, which has blossomed from having a primary focus on discoveries at the interface of physics and biology to being inextricably linked with integrative challenges that span biology, physics, mathematics and engineering. Copyright © 2017 Elsevier Ltd. All rights reserved.

  1. Invertebrate neurophylogeny

    DEFF Research Database (Denmark)

    Richter, Stefan; Loesel, Rudi; Purschke, Günter

    2010-01-01

    Invertebrate nervous systems are highly disparate between different taxa. This is reflected in the terminology used to describe them, which is very rich and often confusing. Even very general terms such as 'brain', 'nerve', and 'eye' have been used in various ways in the different animal groups......, but no consensus on the exact meaning exists. This impedes our understanding of the architecture of the invertebrate nervous system in general and of evolutionary transformations of nervous system characters between different taxa....

  2. A summary of the benthic-invertebrate and fish-community data from streams in the Indianapolis metropolitan area, Indiana, 1981-2012

    Science.gov (United States)

    Voelker, David C.; Bunch, Aubrey R.; Dobrowolski, Edward G.; Shoda, Megan E.

    2015-01-01

    Intermittently, during 1981–2012, the U.S. Geological Survey sampled sites in the White River and several tributaries in the Indianapolis metropolitan area of Indiana for benthic invertebrates and fish communities. During 1981–87, one study focused on benthic-invertebrate data collection at three sites along the White River. During 1994–96, 21 sites were sampled for benthic invertebrates; after 1999, up to 13 sites were sampled for benthic invertebrates and fish communities. The information collected during these studies was used in conjunction with the Indianapolis Department of Public Works and CWA Authority, Inc., programs to help improve overall health of the White River and its tributaries by reducing combined sewer overflows and other point and non-point sources of pollution in the Indianapolis area.

  3. Study of Water Quality Value in Sub of the Stream Area of Cisadane Rivers Upstream as Reference Area Based on Macro invertebrate Composition

    International Nuclear Information System (INIS)

    Sri-Unon-Purwati

    2001-01-01

    Specific structure of biota community condition can used as indicator for the ecosystem stability value or the waters pollution level where the aquatic biota exist. the macro invertebrates as bio indicator organism can used to assess the upper Cisadane Sub River Basin water quality. The grouping and calculation result from family number, Ept presences (sensitive macro invertebrate), Diversity index (H ' ), DO value and TOC value showed 5 criteria of water quality as reference site. This criteria is used to determine water quality level from ten branches of rivers in the upper Cisadane Sub River Basin, Cijeruk districts. The biotic index calculation for ASPT (Average Score Per Taxon) and T and T (index Trihadiningrum and Tjindronegoro) is used to asses water quality based on macro invertebrate composition indicator. Both biotic index system support and give the similar evaluation to water quality level from ten branches of river on the upper Cisadane Sub River Basin. The water quality level is described as fellows: station number 4 is assumed as the true reference site, station number 3, 5, 8 are the first alternative reference site, station number 2, 7, 9 are the second alternative reference site and station 1, 6, 10 are the sites which relatively good water quality, but it is not recommended as reference site. The grouping result bases on the cluster system with macro invertebrate similarity composition are described as fellows: 9=10>3=7>1=6>2=8>>5>>4. (author)

  4. Zoology: Invertebrates that Parasitize Invertebrates.

    Science.gov (United States)

    Giribet, Gonzalo

    2016-07-11

    The genome of an orthonectid, a group of highly modified parasitic invertebrates, is drastically reduced and compact, yet it shows the bilaterian gene toolkit. Phylogenetic analyses place the enigmatic orthonectids within Spiralia, although their exact placement remains uncertain. Copyright © 2016 Elsevier Ltd. All rights reserved.

  5. Sediment unmixing using detrital geochronology

    Science.gov (United States)

    Sharman, Glenn R.; Johnstone, Samuel A.

    2017-11-01

    Sediment mixing within sediment routing systems can exert a strong influence on the preservation of provenance signals that yield insight into the effect of environmental forcing (e.g., tectonism, climate) on the Earth's surface. Here, we discuss two approaches to unmixing detrital geochronologic data in an effort to characterize complex changes in the sedimentary record. First, we summarize 'top-down' mixing, which has been successfully employed in the past to characterize the different fractions of prescribed source distributions ('parents') that characterize a derived sample or set of samples ('daughters'). Second, we propose the use of 'bottom-up' methods, previously used primarily for grain size distributions, to model parent distributions and the abundances of these parents within a set of daughters. We demonstrate the utility of both top-down and bottom-up approaches to unmixing detrital geochronologic data within a well-constrained sediment routing system in central California. Use of a variety of goodness-of-fit metrics in top-down modeling reveals the importance of considering the range of allowable that is well mixed over any single best-fit mixture calculation. Bottom-up modeling of 12 daughter samples from beaches and submarine canyons yields modeled parent distributions that are remarkably similar to those expected from the geologic context of the sediment-routing system. In general, mixture modeling has the potential to supplement more widely applied approaches in comparing detrital geochronologic data by casting differences between samples as differing proportions of geologically meaningful end-member provenance categories.

  6. Invertebrates in the Classroom.

    Science.gov (United States)

    Abramson, Charles I.

    1986-01-01

    Describes an inexpensive program using invertebrates as subjects in conditioning demonstrations and experiments. Provides a bibliography of reviews about invertebrate learning in addition to information on obtaining required apparatus and invertebrates.

  7. STREAM

    DEFF Research Database (Denmark)

    Godsk, Mikkel

    This paper presents a flexible model, ‘STREAM’, for transforming higher science education into blended and online learning. The model is inspired by ideas of active and collaborative learning and builds on feedback strategies well-known from Just-in-Time Teaching, Flipped Classroom, and Peer...... Instruction. The aim of the model is to provide both a concrete and comprehensible design toolkit for adopting and implementing educational technologies in higher science teaching practice and at the same time comply with diverse ambitions. As opposed to the above-mentioned feedback strategies, the STREAM...... model supports a relatively diverse use of educational technologies and may also be used to transform teaching into completely online learning. So far both teachers and educational developers have positively received the model and the initial design experiences show promise....

  8. Data Reduction of Laser Ablation Split-Stream (LASS) Analyses Using Newly Developed Features Within Iolite: With Applications to Lu-Hf + U-Pb in Detrital Zircon and Sm-Nd +U-Pb in Igneous Monazite

    Science.gov (United States)

    Fisher, Christopher M.; Paton, Chad; Pearson, D. Graham; Sarkar, Chiranjeeb; Luo, Yan; Tersmette, Daniel B.; Chacko, Thomas

    2017-12-01

    A robust platform to view and integrate multiple data sets collected simultaneously is required to realize the utility and potential of the Laser Ablation Split-Stream (LASS) method. This capability, until now, has been unavailable and practitioners have had to laboriously process each data set separately, making it challenging to take full advantage of the benefits of LASS. We describe a new program for handling multiple mass spectrometric data sets collected simultaneously, designed specifically for the LASS technique, by which a laser aerosol is been split into two or more separate "streams" to be measured on separate mass spectrometers. New features within Iolite (https://iolite-software.com) enable the capability of loading, synchronizing, viewing, and reducing two or more data sets acquired simultaneously, as multiple DRSs (data reduction schemes) can be run concurrently. While this version of Iolite accommodates any combination of simultaneously collected mass spectrometer data, we demonstrate the utility using case studies where U-Pb and Lu-Hf isotope composition of zircon, and U-Pb and Sm-Nd isotope composition of monazite were analyzed simultaneously, in crystals showing complex isotopic zonation. These studies demonstrate the importance of being able to view and integrate simultaneously acquired data sets, especially for samples with complicated zoning and decoupled isotope systematics, in order to extract accurate and geologically meaningful isotopic and compositional data. This contribution provides instructions and examples for handling simultaneously collected laser ablation data. An instructional video is also provided. The updated Iolite software will help to fully develop the applications of both LASS and multi-instrument mass spectrometric measurement capabilities.

  9. Detrital Zircons Split Sibumasu in East Gondwana

    Science.gov (United States)

    Zhang, X.; Chung, S. L.

    2017-12-01

    It is widely accepted that Sibumasu developed as a united terrane and originated from NW Australian margin in East Gondwana. Here we report new detrital zircon U-Pb-Hf isotopic data from Sumatra that, in combination with literature data, challenge and refute the above long-held view. In particular, the East and West Sumatra terranes share nearly identical Precambrian to Paleozoic detrital zircon age distributions and Hf isotopes, indicating a common provenance/origin for them. The Sumatra detrital zircons exhibit a prominent population of ca. 1170-1070 Ma, indistinguishable from those of the Lhasa and West Burma terranes, with detritus most probably sourcing from western Australia. By contrast, Sibuma (Sibumasu excluding Sumatra) detrital zircons display a prevailing population of ca. 980-935 Ma, strongly resembling those of the western Qiangtang terrane, with detrital materials most likely derived from Greater India and Himalayas. Such markedly distinct detrital zircon age profiles between Sumatra and Sibuma require disparate sources/origin for them, provoking disintegration of the widely-adopted, but outdated, term Sibumasu and thus inviting a new configuration of East Gondwana in the early Paleozoic, with Sumatra and West Burma lying outboard the Lhasa terrane in the NW Australian margin and Sibuma situated in the northern Greater Indian margin. More future investigations are needed to establish the precise rifting and drifting histories of Sumatra and Sibuma, as two separated terranes, during the breakup of Gondwana.

  10. Leaf litter processing in West Virginia mountain streams: effects of temperature and stream chemistry

    Science.gov (United States)

    Jacquelyn M. Rowe; William B. Perry; Sue A. Perry

    1996-01-01

    Climate change has the potential to alter detrital processing in headwater streams, which receive the majority of their nutrient input as terrestrial leaf litter. Early placement of experimental leaf packs in streams, one month prior to most abscission, was used as an experimental manipulation to increase stream temperature during leaf pack breakdown. We studied leaf...

  11. Student-Centred Experiments with Stream Invertebrates

    Science.gov (United States)

    Vaughan, Ian; Larsen, Stefano; Durance, Isabelle; Ormerod, Steve

    2011-01-01

    Field experiments are at the core of ecology, yet rarely find their way into education, probably due to a combination of technical challenges and risks associated with fieldwork. This may compromise student education and perception of the subject, making interesting, readily manageable experiments extremely important. We describe how the daily…

  12. Cosmogenic 3He in detrital gold

    Science.gov (United States)

    Stuart, Finlay; Yakubovich, Olga; Caracedo, Ana; Nesterenok, Alexander

    2017-04-01

    Since the measurement of cosmogenic He in an alluvial diamond by McConville and Reynolds (1996) the application of cosmogenic noble gases to individual detrital grains to quantify surface processes has not been vigorously pursued. The likely low rate of diffusion of cosmogenic He in native metals, and their resistance to weathering and disintegration during erosion and transport, makes them a potential record of long-term Earth surface processes. In an effort to assess the extent that detrital refractory metals record the exposure history during transport and storage we have undertaken a reconnaissance study of the He isotope composition in 18 grains (2-200 mg) of native gold, copper, silver, and PtPd, Pt3Fe and OsIr alloys from alluvial placer deposits from around the world. 4He is dominantly the result of U and Th decay within the grains, or decay of 190Pt in the Pt-rich alloys. 3He is measurable in 13 grains, concentrations range up to 2.7E+6 atoms/g. 3He/4He are always in excess of the crustal radiogenic ratio, up to 306 Ra. Although nucleogenic 3He produced by (n,α) reactions on 6Li, and 3He from trapped hydrothermal fluids, are present, the majority of the 3He is cosmogenic in origin. Using newly calculated cosmogenic 3He production rates in heavy metals, and a determination of the effect of implantation based on the stopping distances of spallogenic 3He and 3H, the grains have 3Hecos concentrations that are equivalent to 0.35 to 1.5 Ma exposure at Earth's surface. In a study of detrital gold grains from several sites in Scotland we have found that 10 % have 3He concentrations that are significantly in excess of that generated since the Last Glacial Maximum. These studies demonstrate that, with refinement, cosmogenic 3He in refractory detrital minerals can be used to quantify sediment transport and storage on the 1-10 Ma timescale. P. McConville & J.H. Reynolds (1989). Geochim. Cosmochim. Acta, 53, 2365-75.

  13. Immune memory in invertebrates.

    Science.gov (United States)

    Milutinović, Barbara; Kurtz, Joachim

    2016-08-01

    Evidence for innate immune memory (or 'priming') in invertebrates has been accumulating over the last years. We here provide an in-depth review of the current state of evidence for immune memory in invertebrates, and in particular take a phylogenetic viewpoint. Invertebrates are a very heterogeneous group of animals and accordingly, evidence for the phenomenon of immune memory as well as the hypothesized molecular underpinnings differ largely for the diverse invertebrate taxa. The majority of research currently focuses on Arthropods, while evidence from many other groups of invertebrates is fragmentary or even lacking. We here concentrate on immune memory that is induced by pathogenic challenges, but also extent our view to a non-pathogenic context, i.e. allograft rejection, which can also show forms of memory and can inform us about general principles of specific self-nonself recognition. We discuss definitions of immune memory and a number of relevant aspects such as the type of antigens used, the route of exposure, and the kinetics of reactions following priming. Copyright © 2016 Elsevier Ltd. All rights reserved.

  14. Antifouling Compounds from Marine Invertebrates.

    Science.gov (United States)

    Qi, Shu-Hua; Ma, Xuan

    2017-08-28

    In this review, a comprehensive overview about the antifouling compounds from marine invertebrates is described. In total, more than 198 antifouling compounds have been obtained from marine invertebrates, specifically, sponges, gorgonian and soft corals.

  15. Aquarium Culture of Freshwater Invertebrates.

    Science.gov (United States)

    Wood, Timothy S.

    1996-01-01

    Describes two methods for rearing small aquatic invertebrates using submerged surfaces in an unfiltered current of water where fish are present. Presents suggestions on how to use the invertebrate communities in the classroom. (JRH)

  16. Antifouling Compounds from Marine Invertebrates

    OpenAIRE

    Qi, Shu-Hua; Ma, Xuan

    2017-01-01

    In this review, a comprehensive overview about the antifouling compounds from marine invertebrates is described. In total, more than 198 antifouling compounds have been obtained from marine invertebrates, specifically, sponges, gorgonian and soft corals.

  17. Invertebrates and Plants :: NOAA Fisheries

    Science.gov (United States)

    Invertebrates & Plants Species of Concern Threatened & Endangered Health & Stranding Marine Mammals Chart Partnerships Fisheries Home » Protected Resources » Species Invertebrates and Plants White Marine Sanctuary Mollusks, corals, and brachiopods are three groups of marine invertebrates. To view ESA

  18. Invertebrates and Plants

    Science.gov (United States)

    Wendell R. Haag; Robert J. Distefano; Siobhan Fennessy; Brett D. Marshall

    2013-01-01

    Invertebrates and plants are among the most ubiquitous and abundant macroscopic organisms in aquatic ecosystems; they dominate most habitats in both diversity and biomass and play central roles in aquatic food webs. Plants regulate and create habitats for a wide array of organisms (Cooke et al. 2005). Snail grazing and bivalve filtering profoundly alter habitats and...

  19. Tube-dwelling invertebrates

    NARCIS (Netherlands)

    Hölker, Franz; Vanni, Michael J.; Kuiper, Jan J.; Meile, Christof; Grossart, Hans Peter; Stief, Peter; Adrian, Rita; Lorke, Andreas; Dellwig, Olaf; Brand, Andreas; Hupfer, Michael; Mooij, Wolf M.; Nützmann, Gunnar; Lewandowski, Jörg

    2015-01-01

    There is ample evidence that tube-dwelling invertebrates such as chironomids significantly alter multiple important ecosystem functions, particularly in shallow lakes. Chironomids pump large water volumes, and associated suspended and dissolved substances, through the sediment and thereby compete

  20. Invertebrates in managed waterfowl marshes

    Science.gov (United States)

    Stafford, Joshua D.; Janke, Adam K.; Webb, Elisabeth B.; Chipps, Steven R.

    2016-01-01

    Invertebrates are an important food for breeding, migrating, and wintering waterfowl. Sparse study has been devoted to understanding the influence of waterfowl and wetland management on production of invertebrates for waterfowl foods; however, manipulation of hydrology and soils may change or enhance production. Fish can compete with waterfowl for invertebrate forage in wetlands and harm aquatic macrophytes; biomanipulation (e.g., stocking piscivores) may improve waterfowl habitat quality. Similarly, some terrestrial vertebrates (e.g., beaver (Castor canadensis)) may positively or negatively impact invertebrate communities in waterfowl habitats. Various challenges exist to wetland management for invertebrates for waterfowl, but the lack of data on factors influencing production may be the most limiting.

  1. Identification of Detrital Carbonate in East Cepu High

    Science.gov (United States)

    Sari, R.; Andika, I. K.; Haris, A.; Miftah, A.

    2018-03-01

    East Cepu High is a part of horst – graben series which formed by extensional tectonic processes during Paleogene in North East Java Basin. Due to excellent paleogeography position, the carbonate build-up was growth very well and as the main reservoir in East Cepu High. Sea level change have important factor to provide variation of facies in each carbonate buildup, one of emerging facies is detrital carbonate. Detrital carbonate indicated by onlap horizon featured with carbonate build up body. Based on paleogeography, fluctuation of sea level change and sediment source, detrital carbonate formed in leeward area in lowstand or highstand phases. Distinguish between detrital carbonate facies with other facies, advanced seismic processing performed by using continuous wavelet transform (CWT) and seismic inversion. CWT is one method of spectral decomposition used to find the frequency that represent a facies. The result from seismic inversion will support the interpretation for facies distribution. As the result, seismic data which have interval frequency 10 – 45 Hz and Acoustic Impedance (AI) value above 35000 (from cross plot between acoustic impedance and gamma ray) can be interpreted as detrital carbonate. Based on seismic interpretation, detrital carbonate facies distributed along leeward area with geometrical spreading. The lateral facies change from detrital carbonate to shale was identified which causing this facies become potential as hydrocarbon reservoir with stratigraphic trap. Based on the earlier studies, North East Java Basin have a strong hydrocarbon migration to fill the reservoir, therefore the detrital carbonate have high chance to be a new hydrocarbon prospect in this area.

  2. 3-D Characterization of Detrital Zircon Grains and its Implications for Fluvial Transport, Mixing, and Preservation Bias

    Science.gov (United States)

    Markwitz, V.; Kirkland, C. L.; Mehnert, A.; Gessner, K.; Shaw, J.

    2017-12-01

    Detrital zircon studies can suffer from selective loss of provenance information due to U-Pb age discordance, metamictization, metamorphic overprinting and fluviatile transport processes. The relationship between isotopic composition and zircon grain shape, and how grain shape is modified during transport, is largely unknown. We combine X-ray tomography with U-Pb geochronology to quantify how fluvial transport affects 3-D zircon shape, detrital age signature, and grain density along the Murchison River, whose catchment comprises Eoarchean to Early Paleozoic source rocks in Western Australia. We acquired tomographic volumes and isotopic data from 373 detrital zircons to document changes in size, shape and density in transport direction, and explore how grain shape, age spectra and the proportion of discordant material vary along the channel. Results show that shape characteristics are sensitive to transport distance, stream gradient, proximity to source material, and whether the source consists of primary or recycled zircons. With increasing transport distance, grain lengths decrease more than their widths. Furthermore, the loss of metamict grains occurs at a near constant rate, resulting in a linear increase of mean calculated zircon density by ca. 0.03 g/cm3 per 100 km transport distance. 3-D grain shape is therefore strongly linked to detrital age signature, and mean grain density is a function of the absolute transport distance. 3-D shape characteristics provide valuable information on detrital zircon populations, including the interaction between source materials with fluvial transport processes, which significantly affects preservation bias and, by inference, the representativeness of the sampled data.

  3. 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

  4. Insects and other invertebrates

    Science.gov (United States)

    John R. Jones; Norbert V. DeByle; Diane M. Bowers

    1985-01-01

    Quaking aspen throughout its range appears to be host to several insect and other invertebrate pests (fig. 1). It is a short-lived species that is palatable to a large variety of animals. Furniss and Carolin (1977) listed 33 insect species that use aspen as a food source. Some are quite damaging and may kill otherwise healthy stands of aspen; others feed on weakened or...

  5. Invertebrate welfare: an overlooked issue

    Directory of Open Access Journals (Sweden)

    Kelsey Horvath

    2013-03-01

    Full Text Available While invertebrates make up the majority of animal species, their welfare is overlooked compared to the concern shown to vertebrates. This fact is highlighted by the near absence of regulations in animal research, with the exception of cephalopods in the European Union. This is often justified by assumptions that invertebrates do not experience pain and stress while lacking the capacity for higher order cognitive functions. Recent research suggests that invertebrates may be just as capable as vertebrates in experiencing pain and stress, and some species display comparable cognitive capacities. Another obstacle is the negative view of invertebrates by the public, which often regards them as pests with no individual personalities, gastronomic entities, or individuals for scientific experimentation without rules. Increasingly, studies have revealed that invertebrates possess individual profiles comparable to the personalities found in vertebrates. Given the large economic impact of invertebrates, developing certain attitude changes in invertebrate welfare may be beneficial for producers while providing higher welfare conditions for the animals. While the immense number and type of species makes it difficult to suggest that all invertebrates will benefit from increased welfare, in this review we provide evidence that the topic of invertebrate welfare should be revisited, more thoroughly investigated, and in cases where appropriate, formally instituted.

  6. Quantifying the influence of sediment source area sampling on detrital thermochronometer data

    Science.gov (United States)

    Whipp, D. M., Jr.; Ehlers, T. A.; Coutand, I.; Bookhagen, B.

    2014-12-01

    Detrital thermochronology offers a unique advantage over traditional bedrock thermochronology because of its sensitivity to sediment production and transportation to sample sites. In mountainous regions, modern fluvial sediment is often collected and dated to determine the past (105 to >107 year) exhumation history of the upstream drainage area. Though potentially powerful, the interpretation of detrital thermochronometer data derived from modern fluvial sediment is challenging because of spatial and temporal variations in sediment production and transport, and target mineral concentrations. Thermochronometer age prediction models provide a quantitative basis for data interpretation, but it can be difficult to separate variations in catchment bedrock ages from the effects of variable basin denudation and sediment transport. We present two examples of quantitative data interpretation using detrital thermochronometer data from the Himalaya, focusing on the influence of spatial and temporal variations in basin denudation on predicted age distributions. We combine age predictions from the 3D thermokinematic numerical model Pecube with simple models for sediment sampling in the upstream drainage basin area to assess the influence of variations in sediment production by different geomorphic processes or scaled by topographic metrics. We first consider a small catchment from the central Himalaya where bedrock landsliding appears to have affected the observed muscovite 40Ar/39Ar age distributions. Using a simple model of random landsliding with a power-law landslide frequency-area relationship we find that the sediment residence time in the catchment has a major influence on predicted age distributions. In the second case, we compare observed detrital apatite fission-track age distributions from 16 catchments in the Bhutan Himalaya to ages predicted using Pecube and scaled by various topographic metrics. Preliminary results suggest that predicted age distributions scaled

  7. CASA in invertebrates.

    Science.gov (United States)

    van der Horst, Gerhard; Bennett, Monique; Bishop, John D D

    2018-04-09

    Sperm movement has been described in several phyla of invertebrates. Yet, sperm motility has only been quantified using computer-aided sperm analysis (CASA-Mot) in externally fertilising species (broadcast spawners) of two phyla, molluscs and echinoderms. In the present study we quantified in detail the nature of the sperm tracks, percentage motility groupings and detailed kinematics of rapid-, medium- and slow-swimming spermatozoa in the oyster Crassostrea gigas and four species never previously studied by CASA-Mot, namely the molluscs Choromytilus meridionalis, Donax serra and Haliotis midae and the echinoderm Parechinus angulosus. A feature common to all these species are the helical tracks, the diameter of which seems to be species specific. Using CASA-Mot, the behaviour of spermatozoa was also studied over time and in the presence of egg water and Ca2+ modulators such as caffeine and procaine hydrochloride. For the first time, we show that hyperactivation can be induced in all species in the presence of egg water (sea water that was mixed with mature eggs and then centrifuged) and/or caffeine, and these hyperactivated sperm tracks were characterised using CASA-Mot. We relate the different patterns of sperm motility and behaviour to reproductive strategies such as broadcast spawning and spermcasting, and briefly review studies using CASA-Mot on other invertebrates.

  8. Incorporating detrital conditioning in outdoor microcosms dosed with JP-8 jet fuel

    International Nuclear Information System (INIS)

    Matthews, R.A.; Markiewicz, A.; Harter, V.; Landis, W.G.

    1995-01-01

    The authors have developed an outdoor microcosm system that incorporates detrital conditioning to test the hypothesis that microbiota play a critical role in altering the community response to hydrocarbon toxicants. The microcosms were constructed using 568 L tanks, arranged in 6 units of 4 tanks, with each unit equidistant from a central conditions tank (CT). During pre-treatment, the microcosms and CT were filled with nutrient-amended well water, artificial sediment, leaf packs containing dried maple leaves, elodea fragment, and unglazed tiles for periphyton growth. Water circulation was maintained at the rate of 24 exchanges per day. After four weeks, invertebrates from local ponds were added to the CT. Leafpacks were added to the CT and microcosms every two weeks; eight week old packs were discarded after returning invertebrates to the CT. On a weekly basis, 25% of the sediments, leaf packs, tiles, and elodea from each microcosms were transferred to another microcosm; the CT walls and tiles were scraped; an the water quality was monitored. Circulation was discontinued one week prior to dosing. On 4/12/96, the microcosms were dosed to contain 0--0.25 microg/L of JP-8 jet fuel. Within two weeks the GC/MS hydrocarbon concentrations were very low in the water column of the highest treatment group. There has been little acute toxicity, despite selecting doses that caused severe, acute toxicity in laboratory microcosm studies. The presence of a complex, detritus-based microbial community appears to mitigate the influences of the toxicant on the microcosms

  9. Detrital carbon pools in temperate forests: magnitude and potential for landscape-scale assessment

    Science.gov (United States)

    John Bradford; Peter Weishampel; Marie-Louise Smith; Randall Kolka; Richard A. Birdsey; Scott V. Ollinger; Michael G. Ryan

    2009-01-01

    Reliably estimating carbon storage and cycling in detrital biomass is an obstacle to carbon accounting. We examined carbon pools and fluxes in three small temperate forest landscapes to assess the magnitude of carbon stored in detrital biomass and determine whether detrital carbon storage is related to stand structural properties (leaf area, aboveground biomass,...

  10. Stream Insect Production as a Function of Alkalinity and Detritus Processing

    OpenAIRE

    Osborn, Thomas G.

    1981-01-01

    The study was conducted to determine if aquatic insect production was significantly different between high and low alkalinity mountain streams and if any differences were associated with food availability factors. The major objectives included determining: (1) if annual production differences occur between high and low alkalinity streams; (2) if processing rates of terrestrial detritus differs between high and low alkalinity streams; (3) if detrital processing rates are related to stream inse...

  11. Invertebrate diversity in southern California

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — This shapefile displays mean invertebrate diversity within 5 minute grid cells. The Shannon Index of diversity was calculated from Southern California Coastal Water...

  12. Louisiana ESI: INVERT (Invertebrate Polygons)

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — This data set contains sensitive biological resource data for marine and estuarine invertebrate species, and major concentration areas for harvested or potentially...

  13. Alabama ESI: INVERT (Invertebrate Polygons)

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — This data set contains sensitive biological resource data for marine and estuarine invertebrate species in Alabama. Vector polygons in this data set represent...

  14. Virginia ESI: INVERT (Invertebrate Polygons)

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — This data set contains sensitive biological resource data for marine, estuarine, and rare invertebrate species in Virginia. Vector polygons in this data set...

  15. The invertebrate communities

    International Nuclear Information System (INIS)

    FloBner, D.; Kasprzak, P.; Mothes, G.; Ronneberger, D.; Schonborn, W.

    1985-01-01

    Studies of invertebrate communities have been carried out to a certain extent in the whole Lake Stechlin area, but especially with reference to Lake Stechlin. The chapter summarizes important results of detailed investigations over a long period, made by several researchers in the periods before and after the nuclear power plant came into operation. The following sections deal with the combination of species, frequency, types of life-form, structure and dynamics of the living community of zoobenthos and zooplankton. Not dealt with or only considered in passing are Amoebina, Heliozoa, Ciliata, Turbellaria (excl. Tricladida), Nematoda, Tardigrada, Gastrotricha, and partly Oligochaeta. The research into micro-and meiooobenthos are limited to the years 1959-1968. Data after the bringing into operation of the nuclear power plant refer only to macrozoobenthos. Before the operation of the nuclear power plant the planktonic Rotaroria and Crustacea were examined only qualitatively. The first quantitative analysis of the zooplankton-community was undertaken in 1968, and only from 1978 onwards has continuous and comprehensive research information about the zooplankton in Lake Stechlin been available

  16. RUNX in Invertebrates.

    Science.gov (United States)

    Hughes, S; Woollard, A

    2017-01-01

    Runx genes have been identified in all metazoans and considerable conservation of function observed across a wide range of phyla. Thus, insight gained from studying simple model organisms is invaluable in understanding RUNX biology in higher animals. Consequently, this chapter will focus on the Runx genes in the diploblasts, which includes sea anemones and sponges, as well as the lower triploblasts, including the sea urchin, nematode, planaria and insect. Due to the high degree of functional redundancy amongst vertebrate Runx genes, simpler model organisms with a solo Runx gene, like C. elegans, are invaluable systems in which to probe the molecular basis of RUNX function within a whole organism. Additionally, comparative analyses of Runx sequence and function allows for the development of novel evolutionary insights. Strikingly, recent data has emerged that reveals the presence of a Runx gene in a protist, demonstrating even more widespread occurrence of Runx genes than was previously thought. This review will summarize recent progress in using invertebrate organisms to investigate RUNX function during development and regeneration, highlighting emerging unifying themes.

  17. Associative Learning in Invertebrates

    Science.gov (United States)

    Hawkins, Robert D.; Byrne, John H.

    2015-01-01

    This work reviews research on neural mechanisms of two types of associative learning in the marine mollusk Aplysia, classical conditioning of the gill- and siphon-withdrawal reflex and operant conditioning of feeding behavior. Basic classical conditioning is caused in part by activity-dependent facilitation at sensory neuron–motor neuron (SN–MN) synapses and involves a hybrid combination of activity-dependent presynaptic facilitation and Hebbian potentiation, which are coordinated by trans-synaptic signaling. Classical conditioning also shows several higher-order features, which might be explained by the known circuit connections in Aplysia. Operant conditioning is caused in part by a different type of mechanism, an intrinsic increase in excitability of an identified neuron in the central pattern generator (CPG) for feeding. However, for both classical and operant conditioning, adenylyl cyclase is a molecular site of convergence of the two signals that are associated. Learning in other invertebrate preparations also involves many of the same mechanisms, which may contribute to learning in vertebrates as well. PMID:25877219

  18. Pesticide runoff from energy crops: A threat to aquatic invertebrates?

    Science.gov (United States)

    Bunzel, Katja; Schäfer, Ralf B; Thrän, Daniela; Kattwinkel, Mira

    2015-12-15

    The European Union aims to reach a 10% share of biofuels in the transport sector by 2020. The major burden is most likely to fall on already established annual energy crops such as rapeseed and cereals for the production of biodiesel and bioethanol, respectively. Annual energy crops are typically cultivated in intensive agricultural production systems, which require the application of pesticides. Agricultural pesticides can have adverse effects on aquatic invertebrates in adjacent streams. We assessed the relative ecological risk to aquatic invertebrates associated with the chemical pest management from six energy crops (maize, potato, sugar beet, winter barley, winter rapeseed, and winter wheat) as well as from mixed cultivation scenarios. The pesticide exposure related to energy crops and cultivation scenarios was estimated as surface runoff for 253 small stream sites in Central Germany using a GIS-based runoff potential model. The ecological risk for aquatic invertebrates, an important organism group for the functioning of stream ecosystems, was assessed using acute toxicity data (48-h LC50 values) of the crustacean Daphnia magna. We calculated the Ecological Risk from potential Pesticide Runoff (ERPR) for all three main groups of pesticides (herbicides, fungicides, and insecticides). Our findings suggest that the crops potato, sugar beet, and rapeseed pose a higher ecological risk to aquatic invertebrates than maize, barley, and wheat. As maize had by far the lowest ERPR values, from the perspective of pesticide pollution, its cultivation as substrate for the production of the gaseous biofuel biomethane may be preferable compared to the production of, for example, biodiesel from rapeseed. Copyright © 2015 Elsevier B.V. All rights reserved.

  19. Biological responses to acidification reversal in Cumbrian streamwaters - invertebrates and bacteria

    Energy Technology Data Exchange (ETDEWEB)

    Tipping, E.; Bass, J.A.B.; Blackburn, J.H.; Hardie, D.J.; Mallinson, H.E.H.; Simon, B.M.

    2000-07-01

    The stream waters of the upper Duddon catchment, situated in the south-west of the English Lake District, have been acidified as a result of acid deposition. However, there is now strong chemical evidence for recovery, as the acidity of deposition decreases. The present study was carried out in order to investigate possible improvements in biological response. This report describes the results of sampling and analysis, carried out to obtain biological data in 1999 for comparison with data obtained in the 1960s and early 1970s for invertebrates and in the 1980s for bacteria. Macro-invertebrate studies were carried out in five streams which had records from the 1960s and 1970s, and which covered a range of pH (ca. 5 to ca. 7). Significantly more macro-invertebrate taxa were found in all the streams in 1999. The macro-invertebrate diversity was greater in 1999, as judged by the Margalef diversity index. There have been significant increases in the values of a macro-invertebrate based acidification index between the 1960s/1970s and the present, consistent with a decrease in stream water acidity. Species of the bacterium Cytophaga, which participates in the decomposition of plant litter, are absent from streams of low pH. Cytophaga was detected in a stream from which it had previously absent, which is consistent with an increase in pH. Taking the results of the present study together with those of previous ones showing that stream and lake acidity in Cumbria have decreased over the last 20-30 years, it can be concluded that decreases in acid deposition (of S) have led to improvements in water quality, and thereby to positive biological responses. (author)

  20. Association of bacteria with marine invertebrates: Implications for ballast water management

    Digital Repository Service at National Institute of Oceanography (India)

    Khandeparker, L.; Anil, A.C.

    stream_size 36739 stream_content_type text/plain stream_name EcoHealth_10_268a.pdf.txt stream_source_info EcoHealth_10_268a.pdf.txt Content-Encoding UTF-8 Content-Type text/plain; charset=UTF-8 1 Author version: EcoHealth... transportation, can have direct impact on society and human health. Ship’s ballast tanks hold different non-indigenous vertebrates, invertebrates, plants, microscopic algae, bacteria etc. (Williams et al. 1988; Carlton and Geller 1993; Smith et al. 1996...

  1. Alternative adaptive immunity in invertebrates

    DEFF Research Database (Denmark)

    Kurtz, Joachim; Armitage, Sophie Alice Octavia

    2006-01-01

    Vertebrate adaptive immunity is characterized by challenge-specific long-term protection. This specific memory is achieved through the vast diversity of somatically rearranged immunological receptors such as antibodies. Whether or not invertebrates are capable of a comparable phenotypic plasticity...

  2. Benthic invertebrates in the headwaters of the Wye and Severn: effects of forestry and clear-felling

    Science.gov (United States)

    Gee, J. H. R.; Smith, B. D.

    Invertebrate communities were recorded in three surveys between 1974 and 1994 of headwaters of the Wye and Severn at Plynlimon: the Afon Gwy (unforested), the Afon Hore (initially forested) and the Afon Hafren (forested throughout). The data cover periods before and after the clear-felling of a large area of coniferous forest in the catchment of the Hore. All three streams contained invertebrates characteristic of acidic, upland conditions and had similar species richness. Differences in assemblage composition within streams between surveys could be related to differences in method or timing of sampling. All assemblages were dominated by Insecta, particularly Plecoptera and Diptera, whereas Ephemeroptera, Moilusca, Crustacca and some families of Trichoptera (notably Hydropsychidae and Philopotamidae) were poorly represented. The forested streams (Hafren and Hore) contained similar assemblages which differed from those in the unforested stream (Gwy) in containing lower densities of Ephemeroptera and Oligochacta and much higher densities of nemourid and leuctrid Plecoptera. Clear-felling of the Hore catchment resulted in changes in physical and chemical conditions (including a reduction of stream pH, and increases in dissolved aluminium concentration and summer water temperature) but no related change in the invertebrate assemblage. The apparent failure of invertebrates to respond as expected to substantial changes in local environmental conditions may reflect either a lack of understanding of causal links between invertebrates and environmental factors, or the over-riding influence of the dynamics of recruitment to populations.

  3. Reliability of a method of sampling stream invertebrates

    CSIR Research Space (South Africa)

    Chutter, FM

    1966-05-01

    Full Text Available In field ecological studies inferences must often be drawn from dissimilarities in numbers and species of organisms found in biological samples collected at different times and under various conditions....

  4. Multi-scale streambed topographic and discharge effects on hyporheic at the stream network scale in confined streams

    Science.gov (United States)

    Alessandra Marzadri; Daniele Tonina; James A. McKean; Matthew G. Tiedemann; Rohan M. Benjankar

    2014-01-01

    The hyporheic zone is the volume of the streambed sediment mostly saturated with stream water. It is the transitional zone between stream and shallow-ground waters and an important ecotone for benthic species, including macro-invertebrates, microorganisms, and some fish species that dwell in the hyporheic zone for parts of their lives. Most hyporheic analyses are...

  5. Antimycobacterial Metabolites from Marine Invertebrates.

    Science.gov (United States)

    Daletos, Georgios; Ancheeva, Elena; Chaidir, Chaidir; Kalscheuer, Rainer; Proksch, Peter

    2016-10-01

    Marine organisms play an important role in natural product-based drug research due to accumulation of structurally unique and bioactive metabolites. The exploration of marine-derived compounds may significantly extend the scientific knowledge of potential scaffolds for antibiotic drug discovery. Development of novel antitubercular agents is especially significant as the emergence of drug-resistant Mycobacterium tuberculosis strains remains threateningly high. Marine invertebrates (i.e., sponges, corals, gorgonians) as a source of new chemical entities are the center of research for several scientific groups, and the wide spectrum of biological activities of marine-derived compounds encourages scientists to carry out investigations in the field of antibiotic research, including tuberculosis treatment. The present review covers published data on antitubercular natural products from marine invertebrates grouped according to their biogenetic origin. Studies on the structure-activity relationships of these important leads are highlighted as well. © 2016 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

  6. Marine Invertebrates: Communities at Risk

    Directory of Open Access Journals (Sweden)

    Jennifer Mather

    2013-06-01

    Full Text Available Our definition of the word ‘animal’ centers on vertebrates, yet 99% of the animals on the planet are invertebrates, about which we know little. In addition, although the Census of Marine Life (COML.org has recently conducted an extensive audit of marine ecosystems, we still do not understand much about the animals of the seas. Surveys of the best-known ecosystems, in which invertebrate populations often play a key role, show that the invertebrate populations are affected by human impact. Coral animals are the foundation of coral reef systems, which are estimated to contain 30% of the species in the ocean. Physical impact and chemical changes on the water severely damage these reefs, and may lead to the removal of these important habitats. Tiny pteropod molluscs live in huge numbers in the polar seas, and their fragile shells are particularly vulnerable to ocean acidification. Their removal would mean that fishes on which we depend would have a hugely diminished food supply. In the North Sea, warming is leading to replacement of colder water copepods by warmer water species which contain less fat. This is having an effect on the birds which eat them, who enrich the otherwise poor land on which they nest. Conversely, the warming of the water and the loss of top predators such as whales and sharks has led to an explosion of the jumbo squid of the Pacific coast of North America. This is positive in the development of a squid fishery, yet negative because the squid eat fish that have been the mainstay of the fishery along that coast. These examples show how invertebrates are key in the oceans, and what might happen when global changes impact them.

  7. Marine invertebrates: communities at risk.

    Science.gov (United States)

    Mather, Jennifer

    2013-06-10

    Our definition of the word 'animal' centers on vertebrates, yet 99% of the animals on the planet are invertebrates, about which we know little. In addition, although the Census of Marine Life (COML.org) has recently conducted an extensive audit of marine ecosystems, we still do not understand much about the animals of the seas. Surveys of the best-known ecosystems, in which invertebrate populations often play a key role, show that the invertebrate populations are affected by human impact. Coral animals are the foundation of coral reef systems, which are estimated to contain 30% of the species in the ocean. Physical impact and chemical changes on the water severely damage these reefs, and may lead to the removal of these important habitats. Tiny pteropod molluscs live in huge numbers in the polar seas, and their fragile shells are particularly vulnerable to ocean acidification. Their removal would mean that fishes on which we depend would have a hugely diminished food supply. In the North Sea, warming is leading to replacement of colder water copepods by warmer water species which contain less fat. This is having an effect on the birds which eat them, who enrich the otherwise poor land on which they nest. Conversely, the warming of the water and the loss of top predators such as whales and sharks has led to an explosion of the jumbo squid of the Pacific coast of North America. This is positive in the development of a squid fishery, yet negative because the squid eat fish that have been the mainstay of the fishery along that coast. These examples show how invertebrates are key in the oceans, and what might happen when global changes impact them.

  8. Streams with Strahler Stream Order

    Data.gov (United States)

    Minnesota Department of Natural Resources — Stream segments with Strahler stream order values assigned. As of 01/08/08 the linework is from the DNR24K stream coverages and will not match the updated...

  9. Multistressor predictive models of invertebrate condition in the Corn Belt, USA

    Science.gov (United States)

    Waite, Ian R.; Van Metre, Peter C.

    2017-01-01

    Understanding the complex relations between multiple environmental stressors and ecological conditions in streams can help guide resource-management decisions. During 14 weeks in spring/summer 2013, personnel from the US Geological Survey and the US Environmental Protection Agency sampled 98 wadeable streams across the Midwest Corn Belt region of the USA for water and sediment quality, physical and habitat characteristics, and ecological communities. We used these data to develop independent predictive disturbance models for 3 macroinvertebrate metrics and a multimetric index. We developed the models based on boosted regression trees (BRT) for 3 stressor categories, land use/land cover (geographic information system [GIS]), all in-stream stressors combined (nutrients, habitat, and contaminants), and for GIS plus in-stream stressors. The GIS plus in-stream stressor models had the best overall performance with an average cross-validation R2 across all models of 0.41. The models were generally consistent in the explanatory variables selected within each stressor group across the 4 invertebrate metrics modeled. Variables related to riparian condition, substrate size or embeddedness, velocity and channel shape, nutrients (primarily NH3), and contaminants (pyrethroid degradates) were important descriptors of the invertebrate metrics. Models based on all measured in-stream stressors performed comparably to models based on GIS landscape variables, suggesting that the in-stream stressor characterization reasonably represents the dominant factors affecting invertebrate communities and that GIS variables are acting as surrogates for in-stream stressors that directly affect in-stream biota.

  10. Utilization of detrital complexes by the oyster, Crassostrea virginica (Gmelin)

    International Nuclear Information System (INIS)

    Crosby, M.P.

    1987-01-01

    The contribution of bacteria and nonliving particulate organic matter of detrital complexes to the nutrition of the American oyster, Crassostrea virginica, was investigated in the laboratory under normal feeding conditions. Results indicate the oysters were capable of assimilating crude fiber extracted from 14 C-Spartina alterniflora with an efficiency of approximately 3% and that enteric bacteria did not enhance this process. Less than 1% of an oyster's energetic demands could be met by direct utilization of this substrate, in the Choptank River subestuary of the Chesapeake Bay. The potential contribution of refractory organics to oysters in large salt marshes having crude fiber concentration greater than in the Choptank system, are discussed. The ability of the oyster to utilize 14 C and 15 N from cellulolytic marine bacteria, isolated from a S. alterniflora dominated salt marsh, was also studied

  11. In situ detrital zircon (U-Th)/He thermochronology

    Science.gov (United States)

    Tripathy, A.; Monteleone, B. D.; van Soest, M. C.; Hodges, K.; Hourigan, J. K.

    2010-12-01

    Detrital studies of both sand and rock are relevant to many problems, ranging from the climate and tectonics feedback debate to the long-term record of orogenic evolution. When applying the conventional (U-Th)/He technique to such studies, two important issues arise. Often, only euhedral grains are permissible for analysis in order to make simple geometric corrections for α-recoil. In detrital samples, this is problematic because euhedral grains can be scarce due to mechanical abrasion during transport, and potentially introduce bias in favour of more proximally sourced grains. Second, inherent to detrital studies is the need to date many grains (>100) per sample to ensure a representative sampling of the sediment source region, thus making robust conventional detrital studies both expensive and time-consuming. UV laser microprobes can improve this by permitting careful targeting of the grain interior away from the α-ejection zone, rendering the α-recoil correction unnecessary, thus eliminating bias toward euhedral grains. In the Noble Gas, Geochemistry, and Geochronology Laboratory at ASU, apatite and zircon have been successfully dated using in situ methods. For this study, the conventional and in situ techniques are compared by dating zircons from a modern river sand that drains a small catchment in the Mesozoic-Cenozoic Ladakh Batholith in NW India. This sample has a simple provenance, which allows us to demonstrate the robustness of the in situ method. Moreover, different microbeam techniques will be explored to establish the most efficient approach to obtain accurate and precise U-Th concentrations using synrock, which is our powdered, homogenized, and reconstituted zircon-rock standard. Without this, such in situ U-Th data would be difficult to obtain. 117 zircons were dated using the conventional (U-Th)/He method, revealing dates ranging from 9.70±0.35 to 106.6±3.5 Ma (2σ) with the major mode at 26 Ma. For comparison, 44 grains were dated using the in

  12. The Global Invertebrate Genomics Alliance (GIGA): Developing Community Resources to Study Diverse Invertebrate Genomes

    KAUST Repository

    Bracken-Grissom, Heather; Collins, Allen G.; Collins, Timothy; Crandall, Keith; Distel, Daniel; Dunn, Casey; Giribet, Gonzalo; Haddock, Steven; Knowlton, Nancy; Martindale, Mark; Medina, Monica; Messing, Charles; O'Brien, Stephen J.; Paulay, Gustav; Putnam, Nicolas; Ravasi, Timothy; Rouse, Greg W.; Ryan, Joseph F.; Schulze, Anja; Worheide, Gert; Adamska, Maja; Bailly, Xavier; Breinholt, Jesse; Browne, William E.; Diaz, M. Christina; Evans, Nathaniel; Flot, Jean-Francois; Fogarty, Nicole; Johnston, Matthew; Kamel, Bishoy; Kawahara, Akito Y.; Laberge, Tammy; Lavrov, Dennis; Michonneau, Francois; Moroz, Leonid L.; Oakley, Todd; Osborne, Karen; Pomponi, Shirley A.; Rhodes, Adelaide; Rodriguez-Lanetty, Mauricio; Santos, Scott R.; Satoh, Nori; Thacker, Robert W.; Van de Peer, Yves; Voolstra, Christian R.; Welch, David Mark; Winston, Judith; Zhou, Xin

    2013-01-01

    Over 95% of all metazoan (animal) species comprise the invertebrates, but very few genomes from these organisms have been sequenced. We have, therefore, formed a Global Invertebrate Genomics Alliance (GIGA). Our intent is to build a collaborative

  13. Molecular Basis for Ultraviolet Vision in Invertebrates

    OpenAIRE

    Salcedo, Ernesto; Zheng, Lijun; Phistry, Meridee; Bagg, Eve E.; Britt, Steven G.

    2003-01-01

    Invertebrates are sensitive to a broad spectrum of light that ranges from UV to red. Color sensitivity in the UV plays an important role in foraging, navigation, and mate selection in both flying and terrestrial invertebrate animals. Here, we show that a single amino acid polymorphism is responsible for invertebrate UV vision. This residue (UV: lysine vs blue:asparagine or glutamate) corresponds to amino acid position glycine 90 (G90) in bovine rhodopsin, a site affected in autosomal dominant...

  14. Toxicity of Engineered Nanoparticles to Aquatic Invertebrates

    DEFF Research Database (Denmark)

    Cupi, Denisa; Sørensen, Sara Nørgaard; Skjolding, Lars Michael

    2016-01-01

    This chapter provides a targeted description of some of the most important processes that influence toxicity and uptake of nanoparticles in aquatic invertebrates. It discusses silver nanoparticles (Ag NPs), on how aspects of dissolution and chemical species obtained from this process can influence...... ecotoxicity of aquatic invertebrates. The chapter focuses on how fullerenes affect the toxicity of other pollutants, but also reflect on the fate and behavior of C60 in the aquatic environment, as well as ecotoxicity to aquatic invertebrates. It presents the case of titanium dioxide nanoparticles (TiO2 NPs...... on bioaccumulation focusing on the effect of nanoparticle coating, uptake, and depuration in aquatic invertebrates....

  15. URBANIZATION ALTERS FATTY ACID CONCENTRATIONS OF STREAM FOOD WEBS IN THE NARRAGANSETT BAY WATERSHED

    Science.gov (United States)

    Urbanization and associated human activities negatively affect stream algal and invertebrate assemblages, likely altering food webs. Our goal was to determine if urbanization affects food web essential fatty acids (EFAs) and if EFAs could be useful ecological indicators in monito...

  16. A Field-Based Aquatic Life Benchmark for Conductivity in Central Appalachian Streams (Final Report)

    Science.gov (United States)

    EPA announced the availability of the final report, A Field-Based Aquatic Life Benchmark for Conductivity in Central Appalachian Streams. This report describes a method to characterize the relationship between the extirpation (the effective extinction) of invertebrate g...

  17. The Stream-Catchment (StreamCat) and Lake-Catchment ...

    Science.gov (United States)

    Background/Question/MethodsLake and stream conditions respond to both natural and human-related landscape features. Characterizing these features within contributing areas (i.e., delineated watersheds) of streams and lakes could improve our understanding of how biological conditions vary spatially and improve the use, management, and restoration of these aquatic resources. However, the specialized geospatial techniques required to define and characterize stream and lake watersheds has limited their widespread use in both scientific and management efforts at large spatial scales. We developed the StreamCat and LakeCat Datasets to model, predict, and map the probable biological conditions of streams and lakes across the conterminous US (CONUS). Both StreamCat and LakeCat contain watershed-level characterizations of several hundred natural (e.g., soils, geology, climate, and land cover) and anthropogenic (e.g., urbanization, agriculture, mining, and forest management) landscape features for ca. 2.6 million stream segments and 376,000 lakes across the CONUS, respectively. These datasets can be paired with field samples to provide independent variables for modeling and other analyses. We paired 1,380 stream and 1,073 lake samples from the USEPAs National Aquatic Resource Surveys with StreamCat and LakeCat and used random forest (RF) to model and then map an invertebrate condition index and chlorophyll a concentration, respectively. Results/ConclusionsThe invertebrate

  18. Influence of shredder feeding and nutrients on fungal activity and community structure in headwater streams

    Science.gov (United States)

    Namil Chung; Keller. Suberkropp

    2008-01-01

    In stream detrital food webs, interactions occur between aquatic hyphomycetes associated with decomposing leaves and shredders consuming those leaves. However, few studies have examined how the feeding activity of shredders affects aquatic hyphomycetes. We examined the effect of shredder feeding on aquatic hyphomycete communities associated with submerged leaves in two...

  19. Detrital zircon study along the Tsangpo River, SE Tibet

    Science.gov (United States)

    Liang, Y.; Chung, S.; Liu, D.; O'Reilly, S. Y.; Chu, M.; Ji, J.; Song, B.; Pearson, N. J.

    2004-12-01

    The interactions among tectonic uplift, river erosion and alluvial deposition are fundamental processes that shape the landscape of the Himalayan-Tibetan orogen since its creation from early Cenozoic time. To better understand these processes around the eastern Himalayan Syntaxis, we conducted a study by systematic sampling riverbank sediments along the Tsangpo River, SE Tibet. Detrital zircons separated from the sediments were subjected to U-Pb dating by the SHRIMP II at the Beijing SHRIMP Center and then in-situ measurements of Hf isotope ratios using LA-MC-ICPMS at GEMOC. These results, together with U-Pb ages and Hf isotope data that we recently obtained for the Transhimalayan plutonic and surrounding basement rocks, allow a more quantitative examination of the provenance or protosource areas for the river sediments. Consequently, the percentage inputs from these source areas can be estimated. Our study indicates that, before the Tsangpo River flows into the Namche Barwa Syntaxis of the eastern Himalayas where the River forms a 180° Big Bend gorge and crosscuts the Himalayan sequences, the Gangdese batholith that crops out just north of the River appear to be an overwhelming source accounting for ˜50 % of the bank sediments. The Tethyan Himalayan sequences south of the River are the second important source, with an input of ˜25 %. The proportion of sediment supply changes after the River enters the Big Bend gorge and turns to south: ˜25 % of detrital zircons are derived from the Greater Himalayas so that the input from the Tethyan Himalayas decreases (< 10 %) despite those from the Gangdese batholith remains high ( ˜40 %). Comparing with the sediment budget of the Brahmaputra River in the downstream based on literature Sr, Nd and Os isotope information, which suggests dominant ( ˜90-60 %) but subordinate ( ˜10-40 %) contributions by the (Greater and Lesser) Himalayan and Tibetan (including Tethyan Himalayan) rocks, respectively, the change is interpreted

  20. Stream Crossings

    Data.gov (United States)

    Vermont Center for Geographic Information — Physical measurements and attributes of stream crossing structures and adjacent stream reaches which are used to provide a relative rating of aquatic organism...

  1. Effects of Pollution on Freshwater Invertebrates.

    Science.gov (United States)

    Buikema, A. L., Jr.; Herricks, E. E.

    1978-01-01

    Presents a literature review of the effects of pollution on freshwater invertebrates, covering publications of 1976-77. Some of the areas covered are: (1) toxicant effects on invertebrates; (2) microcosm and community effects, and (3) biological control of aquatic life. A list of 123 references is also presented. (HM)

  2. Invertebrates, ecosystem services and climate change.

    Science.gov (United States)

    Prather, Chelse M; Pelini, Shannon L; Laws, Angela; Rivest, Emily; Woltz, Megan; Bloch, Christopher P; Del Toro, Israel; Ho, Chuan-Kai; Kominoski, John; Newbold, T A Scott; Parsons, Sheena; Joern, A

    2013-05-01

    The sustainability of ecosystem services depends on a firm understanding of both how organisms provide these services to humans and how these organisms will be altered with a changing climate. Unquestionably a dominant feature of most ecosystems, invertebrates affect many ecosystem services and are also highly responsive to climate change. However, there is still a basic lack of understanding of the direct and indirect paths by which invertebrates influence ecosystem services, as well as how climate change will affect those ecosystem services by altering invertebrate populations. This indicates a lack of communication and collaboration among scientists researching ecosystem services and climate change effects on invertebrates, and land managers and researchers from other disciplines, which becomes obvious when systematically reviewing the literature relevant to invertebrates, ecosystem services, and climate change. To address this issue, we review how invertebrates respond to climate change. We then review how invertebrates both positively and negatively influence ecosystem services. Lastly, we provide some critical future directions for research needs, and suggest ways in which managers, scientists and other researchers may collaborate to tackle the complex issue of sustaining invertebrate-mediated services under a changing climate. © 2012 The Authors. Biological Reviews © 2012 Cambridge Philosophical Society.

  3. Wood decomposition as influenced by invertebrates

    Science.gov (United States)

    Michael D. Ulyshen

    2014-01-01

    The diversity and habitat requirements of invertebrates associated with dead wood have been the subjects of hundreds of studies in recent years but we still know very little about the ecological or economic importance of these organisms. The purpose of this review is to examine whether, how and to what extent invertebrates affect wood decomposition in terrestrial...

  4. An invertebrate stomach's view on vertebrate ecology

    DEFF Research Database (Denmark)

    Calvignac-Spencer, Sébastien; Leendertz, Fabian H.; Gilbert, Tom

    2013-01-01

    Recent studies suggest that vertebrate genetic material ingested by invertebrates (iDNA) can be used to investigate vertebrate ecology. Given the ubiquity of invertebrates that feed on vertebrates across the globe, iDNA might qualify as a very powerful tool for 21st century population...

  5. Complex mixtures of dissolved pesticides show potential aquatic toxicity in a synoptic study of Midwestern U.S. streams

    Science.gov (United States)

    Nowell, Lisa H.; Moran, Patrick W.; Schmidt, Travis S.; Norman, Julia E.; Nakagaki, Naomi; Shoda, Megan E.; Mahler, Barbara J.; Van Metre, Peter C.; Stone, Wesley W.; Sandstrom, Mark W.; Hladik, Michelle L.

    2018-01-01

    Aquatic organisms in streams are exposed to pesticide mixtures that vary in composition over time in response to changes in flow conditions, pesticide inputs to the stream, and pesticide fate and degradation within the stream. To characterize mixtures of dissolved-phase pesticides and degradates in Midwestern streams, a synoptic study was conducted at 100 streams during May–August 2013. In weekly water samples, 94 pesticides and 89 degradates were detected, with a median of 25 compounds detected per sample and 54 detected per site. In a screening-level assessment using aquatic-life benchmarks and the Pesticide Toxicity Index (PTI), potential effects on fish were unlikely in most streams. For invertebrates, potential chronic toxicity was predicted in 53% of streams, punctuated in 12% of streams by acutely toxic exposures. For aquatic plants, acute but likely reversible effects on biomass were predicted in 75% of streams, with potential longer-term effects on plant communities in 9% of streams. Relatively few pesticides in water—atrazine, acetochlor, metolachlor, imidacloprid, fipronil, organophosphate insecticides, and carbendazim—were predicted to be major contributors to potential toxicity. Agricultural streams had the highest potential for effects on plants, especially in May–June, corresponding to high spring-flush herbicide concentrations. Urban streams had higher detection frequencies and concentrations of insecticides and most fungicides than in agricultural streams, and higher potential for invertebrate toxicity, which peaked during July–August. Toxicity-screening predictions for invertebrates were supported by quantile regressions showing significant associations for the Benthic Invertebrate-PTI and imidacloprid concentrations with invertebrate community metrics for MSQA streams, and by mesocosm toxicity testing with imidacloprid showing effects on invertebrate communities at environmentally relevant concentrations. This study documents the most

  6. Akamai Streaming

    OpenAIRE

    ECT Team, Purdue

    2007-01-01

    Akamai offers world-class streaming media services that enable Internet content providers and enterprises to succeed in today's Web-centric marketplace. They deliver live event Webcasts (complete with video production, encoding, and signal acquisition services), streaming media on demand, 24/7 Webcasts and a variety of streaming application services based upon their EdgeAdvantage.

  7. Community structure and diversity of macrobenthic invertebrates in ...

    African Journals Online (AJOL)

    Macrobenthic invertebrates' community structure and diversity in relation to ... Analysis of variance (ANOVA) revealed that there were significant difference ... invertebrates' species distribution and some measured environmental variables.

  8. Lithofacies control in detrital zircon provenance studies: Insights from the Cretaceous Methow basin, southern Canadian Cordillera

    Science.gov (United States)

    DeGraaff-Surpless, K.; Mahoney, J.B.; Wooden, J.L.; McWilliams, M.O.

    2003-01-01

    High-frequency sampling for detrital zircon analysis can provide a detailed record of fine-scale basin evolution by revealing the temporal and spatial variability of detrital zircon ages within clastic sedimentary successions. This investigation employed detailed sampling of two sedimentary successions in the Methow/Methow-Tyaughton basin of the southern Canadian Cordillera to characterize the heterogeneity of detrital zircon signatures within single lithofacies and assess the applicability of detrital zircon analysis in distinguishing fine-scale provenance changes not apparent in lithologic analysis of the strata. The Methow/Methow-Tyaughton basin contains two distinct stratigraphic sequences of middle Albian to Santonian clastic sedimentary rocks: submarine-fan deposits of the Harts Pass Formation/Jackass Mountain Group and fluvial deposits of the Winthrop Formation. Although both stratigraphic sequences displayed consistent ranges in detrital zircon ages on a broad scale, detailed sampling within each succession revealed heterogeneity in the detrital zircon age distributions that was systematic and predictable in the turbidite succession but unpredictable in the fluvial succession. These results suggest that a high-density sampling approach permits interpretation of finescale changes within a lithologically uniform turbiditic sedimentary succession, but heterogeneity within fluvial systems may be too large and unpredictable to permit accurate fine-scale characterization of the evolution of source regions. The robust composite detrital zircon age signature developed for these two successions permits comparison of the Methow/Methow-Tyaughton basin age signature with known plutonic source-rock ages from major plutonic belts throughout the Cretaceous North American margin. The Methow/Methow-Tyaughton basin detrital zircon age signature matches best with source regions in the southern Canadian Cordillera, requiring that the basin developed in close proximity to the

  9. Impacts of fish farm pollution on ecosystem structure and function of tropical headwater streams

    International Nuclear Information System (INIS)

    Rosa, Rodrigo dos Santos; Aguiar, Anna Carolina Fornero; Boëchat, Iola Gonçalves; Gücker, Björn

    2013-01-01

    We investigated the impacts of effluent discharge from small flow-through fish farms on stream water characteristics, the benthic invertebrate community, whole-system nitrate uptake, and ecosystem metabolism of three tropical headwater streams in southeastern Brazil. Effluents were moderately, i.e. up to 20-fold enriched in particulate organic matter (POM) and inorganic nutrients in comparison to stream water at reference sites. Due to high dilution with stream water, effluent discharge resulted in up to 2.0-fold increases in stream water POM and up to 1.8-fold increases in inorganic nutrients only. Moderate impacts on the benthic invertebrate community were detected at one stream only. There was no consistent pattern of effluent impact on whole-stream nitrate uptake. Ecosystem metabolism, however, was clearly affected by effluent discharge. Stream reaches impacted by effluents exhibited significantly increased community respiration and primary productivity, stressing the importance of ecologically sound best management practices for small fish farms in the tropics. -- Highlights: ► Fish farm effluent discharge had moderate effects on stream water quality. ► Impacts on the benthic invertebrate community occurred at one stream. ► Whole-stream nitrate uptake showed no consistent impact pattern. ► Effluents caused considerable increases in stream ecosystem metabolism. ► Compliance with best management practices is important for small fish farms. -- Moderate water pollution by small fish farms caused considerable eutrophication responses in tropical headwater streams

  10. From water to land: How an invasive clam may function as a resource pulse to terrestrial invertebrates.

    Science.gov (United States)

    Novais, Adriana; Souza, Allan T; Ilarri, Martina; Pascoal, Cláudia; Sousa, Ronaldo

    2015-12-15

    Resource pulses are episodes of low frequency, large magnitude and short duration that result in increased resource availability in space and time, with consequences for food web dynamics. Studies assessing the importance of resource pulses by invasive alien species in the interface between terrestrial and aquatic ecosystems are rare, especially those in the direction from water to land. This study assessed the importance of massive die-offs of the Asian clam Corbicula fluminea (Müller, 1774) as a resource pulse to the terrestrial invertebrate community after an extreme climatic event using a manipulative experiment. We used 5 levels of C. fluminea density (0, 100, 500, 1000 and 2000ind·m(-2)), with terrestrial invertebrates being censused 7, 30 and 90days after C. fluminea addition. We also assessed the possible effect of plots position, where plots that delimited the experiment were assigned as edge plots and the remaining as core plots. Clear differences were detected in abundance, biomass, richness and diversity of terrestrial invertebrates depending on the C. fluminea density, time and position. Interestingly, the highest abundance of adult Diptera was observed 7days after C. fluminea addition, whereas that of the other terrestrial invertebrates was on day 30, both with C. fluminea densities higher than 500ind·m(-2) located on the edge of the experimental design. This study highlights the importance of major resource pulses after massive die-offs of invasive bivalves, contributing with remarkable amounts of carrion for adjacent terrestrial systems. Part of this carrion can be consumed directly by a great number of invertebrate species while the remainder can enter the detrital food web. Given the high density and biomass attained by several invasive bivalves worldwide and the predicted increase in the number, intensity and magnitude of extreme climatic events, the ecological importance of this phenomenon should be further investigated. Copyright © 2015

  11. Complex Effects of Ecosystem Engineer Loss on Benthic Ecosystem Response to Detrital Macroalgae.

    Directory of Open Access Journals (Sweden)

    Francesca Rossi

    Full Text Available Ecosystem engineers change abiotic conditions, community assembly and ecosystem functioning. Consequently, their loss may modify thresholds of ecosystem response to disturbance and undermine ecosystem stability. This study investigates how loss of the bioturbating lugworm Arenicola marina modifies the response to macroalgal detrital enrichment of sediment biogeochemical properties, microphytobenthos and macrofauna assemblages. A field manipulative experiment was done on an intertidal sandflat (Oosterschelde estuary, The Netherlands. Lugworms were deliberately excluded from 1× m sediment plots and different amounts of detrital Ulva (0, 200 or 600 g Wet Weight were added twice. Sediment biogeochemistry changes were evaluated through benthic respiration, sediment organic carbon content and porewater inorganic carbon as well as detrital macroalgae remaining in the sediment one month after enrichment. Microalgal biomass and macrofauna composition were measured at the same time. Macroalgal carbon mineralization and transfer to the benthic consumers were also investigated during decomposition at low enrichment level (200 g WW. The interaction between lugworm exclusion and detrital enrichment did not modify sediment organic carbon or benthic respiration. Weak but significant changes were instead found for porewater inorganic carbon and microalgal biomass. Lugworm exclusion caused an increase of porewater carbon and a decrease of microalgal biomass, while detrital enrichment drove these values back to values typical of lugworm-dominated sediments. Lugworm exclusion also decreased the amount of macroalgae remaining into the sediment and accelerated detrital carbon mineralization and CO2 release to the water column. Eventually, the interaction between lugworm exclusion and detrital enrichment affected macrofauna abundance and diversity, which collapsed at high level of enrichment only when the lugworms were present. This study reveals that in nature the

  12. Complex Effects of Ecosystem Engineer Loss on Benthic Ecosystem Response to Detrital Macroalgae.

    Science.gov (United States)

    Rossi, Francesca; Gribsholt, Britta; Gazeau, Frederic; Di Santo, Valentina; Middelburg, Jack J

    2013-01-01

    Ecosystem engineers change abiotic conditions, community assembly and ecosystem functioning. Consequently, their loss may modify thresholds of ecosystem response to disturbance and undermine ecosystem stability. This study investigates how loss of the bioturbating lugworm Arenicola marina modifies the response to macroalgal detrital enrichment of sediment biogeochemical properties, microphytobenthos and macrofauna assemblages. A field manipulative experiment was done on an intertidal sandflat (Oosterschelde estuary, The Netherlands). Lugworms were deliberately excluded from 1× m sediment plots and different amounts of detrital Ulva (0, 200 or 600 g Wet Weight) were added twice. Sediment biogeochemistry changes were evaluated through benthic respiration, sediment organic carbon content and porewater inorganic carbon as well as detrital macroalgae remaining in the sediment one month after enrichment. Microalgal biomass and macrofauna composition were measured at the same time. Macroalgal carbon mineralization and transfer to the benthic consumers were also investigated during decomposition at low enrichment level (200 g WW). The interaction between lugworm exclusion and detrital enrichment did not modify sediment organic carbon or benthic respiration. Weak but significant changes were instead found for porewater inorganic carbon and microalgal biomass. Lugworm exclusion caused an increase of porewater carbon and a decrease of microalgal biomass, while detrital enrichment drove these values back to values typical of lugworm-dominated sediments. Lugworm exclusion also decreased the amount of macroalgae remaining into the sediment and accelerated detrital carbon mineralization and CO2 release to the water column. Eventually, the interaction between lugworm exclusion and detrital enrichment affected macrofauna abundance and diversity, which collapsed at high level of enrichment only when the lugworms were present. This study reveals that in nature the role of this

  13. Effects of elevated CO2 on litter chemistry and subsequent invertebrate detritivore feeding responses.

    Directory of Open Access Journals (Sweden)

    Matthew W Dray

    Full Text Available Elevated atmospheric CO2 can change foliar tissue chemistry. This alters leaf litter palatability to macroinvertebrate detritivores with consequences for decomposition, nutrient turnover, and food-web structure. Currently there is no consensus on the link between CO2 enrichment, litter chemistry, and macroinvertebrate-mediated leaf decomposition. To identify any unifying mechanisms, we presented eight invertebrate species from aquatic and terrestrial ecosystems with litter from Alnus glutinosa (common alder or Betula pendula (silver birch trees propagated under ambient (380 ppm or elevated (ambient +200 ppm CO2 concentrations. Alder litter was largely unaffected by CO2 enrichment, but birch litter from leaves grown under elevated CO2 had reduced nitrogen concentrations and greater C/N ratios. Invertebrates were provided individually with either (i two litter discs, one of each CO2 treatment ('choice', or (ii one litter disc of each CO2 treatment alone ('no-choice'. Consumption was recorded. Only Odontocerum albicorne showed a feeding preference in the choice test, consuming more ambient- than elevated-CO2 birch litter. Species' responses to alder were highly idiosyncratic in the no-choice test: Gammarus pulex and O. albicorne consumed more elevated-CO2 than ambient-CO2 litter, indicating compensatory feeding, while Oniscus asellus consumed more of the ambient-CO2 litter. No species responded to CO2 treatment when fed birch litter. Overall, these results show how elevated atmospheric CO2 can alter litter chemistry, affecting invertebrate feeding behaviour in species-specific ways. The data highlight the need for greater species-level information when predicting changes to detrital processing-a key ecosystem function-under atmospheric change.

  14. Viral diseases of marine invertebrates

    Science.gov (United States)

    Johnson, P. T.

    1984-03-01

    Approximately 40 viruses are known from marine sponges; turbellarian and monogenetic flatworms; cephalopod, bivalve, and gastropod mollusks; nereid polychaetes; and isopod and decapod crustaceans. Most of the viruses can be tentatively assigned to the Herpesviridae, Baculoviridae, Iridoviridae, Adenoviridae, Papovaviridae, Reoviridae, “Birnaviridae”, Bunyaviridae, Rhabdoviridae, and Picornaviridae. Viruslike particles found in oysters might be representatives of the Togaviridae and Retroviridae. Enveloped single-stranded RNA viruses from crustaceans have developmental and morphological characteristics intermediate between families, and some show evidence of relationships to the Paramyxoviridae as well as the Bunyaviridae or Rhabdoviridae. Certain small viruses of shrimp cannot be assigned, even tentatively, to a particular family. Some viruses cause disease in wild and captive hosts, others are associated with disease states but may not be primary instigators, and many occur in apparently normal animals. The frequency of viral disease in natural populations of marine invertebrates is unknown. Several viruses that cause disease in captive animals, with or without experimental intervention, have also been found in diseased wild hosts, including herpeslike viruses of crabs and oysters, iridovirus of octopus, and reolike and bunyalike viruses of crabs. Iridolike viruses have been implicated in massive mortalities of cultured oysters. Baculoviruses, and IHHN virus, which is of uncertain affinities, cause economically damaging diseases in cultured penaeid shrimp. Double or multiple viral infection is common in crabs. For example, a reolike virus and associated rhabdolike virus act synergistically to cause paralytic and fatal disease in Callinectes sapidus. Information on host range, most susceptible stage, and viral latency is available only for viruses of shrimp. One baculovirus attacks five species of New World penaeid shrimp. IHHN virus infects three species of

  15. Columbia River ESI: INVERT (Invertebrate Polygons)

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — This data set contains sensitive biological resource data for clams, oysters, crabs, and other invertebrate species in Columbia River. Vector polygons in this data...

  16. Are invertebrates relevant models in ageing research?

    DEFF Research Database (Denmark)

    Erdogan, Cihan Suleyman; Hansen, Benni Winding; Vang, Ole

    2016-01-01

    is an evolutionary conserved key protein kinase in the TOR pathway that regulates growth, proliferation and cell metabolism in response to nutrients, growth factors and stress. Comparing the ageing process in invertebrate model organisms with relatively short lifespan with mammals provides valuable information about...... the molecular mechanisms underlying the ageing process faster than mammal systems. Inhibition of the TOR pathway activity via either genetic manipulation or rapamycin increases lifespan profoundly in most invertebrate model organisms. This contribution will review the recent findings in invertebrates concerning...... the TOR pathway and effects of TOR inhibition by rapamycin on lifespan. Besides some contradictory results, the majority points out that rapamycin induces longevity. This suggests that administration of rapamycin in invertebrates is a promising tool for pursuing the scientific puzzle of lifespan...

  17. Immune Reactions Among Marine and Other Invertebrates

    Science.gov (United States)

    Bang, Frederik B.

    1973-01-01

    Discusses the defense mechanisms and immune reaction found in invertebrates, and examines the wealth of related biological problems that need study and many of the leads that have recently been developed. (JR)

  18. Uncoupling proteins of invertebrates: A review.

    Science.gov (United States)

    Slocinska, Malgorzata; Barylski, Jakub; Jarmuszkiewicz, Wieslawa

    2016-09-01

    Uncoupling proteins (UCPs) mediate inducible proton conductance in the mitochondrial inner membrane. Herein, we summarize our knowledge regarding UCPs in invertebrates. Since 2001, the presence of UCPs has been demonstrated in nematodes, mollusks, amphioxi, and insects. We discuss the following important issues concerning invertebrate UCPs: their evolutionary relationships, molecular and functional properties, and physiological impact. Evolutionary analysis indicates that the branch of vertebrate and invertebrate UCP4-5 diverged early in the evolutionary process prior to the divergence of the animal groups. Several proposed physiological roles of invertebrate UCPs are energy control, metabolic balance, and preventive action against oxidative stress. © 2016 IUBMB Life, 68(9):691-699, 2016. © 2016 International Union of Biochemistry and Molecular Biology.

  19. Diversity of large DNA viruses of invertebrates.

    Science.gov (United States)

    Williams, Trevor; Bergoin, Max; van Oers, Monique M

    2017-07-01

    In this review we provide an overview of the diversity of large DNA viruses known to be pathogenic for invertebrates. We present their taxonomical classification and describe the evolutionary relationships among various groups of invertebrate-infecting viruses. We also indicate the relationships of the invertebrate viruses to viruses infecting mammals or other vertebrates. The shared characteristics of the viruses within the various families are described, including the structure of the virus particle, genome properties, and gene expression strategies. Finally, we explain the transmission and mode of infection of the most important viruses in these families and indicate, which orders of invertebrates are susceptible to these pathogens. Copyright © 2016 Elsevier Inc. All rights reserved.

  20. Different cesium-137 transfers to forest and stream ecosystems

    International Nuclear Information System (INIS)

    Sakai, Masaru; Gomi, Takashi; Negishi, Junjiro N.; Iwamoto, Aimu; Okada, Kengo

    2016-01-01

    Understanding the mechanisms of "1"3"7Cs movement across different ecosystems is crucial for projecting the environmental impact and management of nuclear contamination events. Here, we report differential movement of "1"3"7Cs in adjacent forest and stream ecosystems. The food webs of the forest and stream ecosystems in our study were similar, in that they were both dominated by detrital-based food webs and the basal energy source was terrestrial litter. However, the concentration of "1"3"7Cs in stream litter was significantly lower than in forest litter, the result of "1"3"7Cs leaching from litter in stream water. The difference in "1"3"7Cs concentrations between the two types of litter was reflected in the "1"3"7Cs concentrations in the animal community. While the importance of "1"3"7Cs fallout and the associated transfer to food webs has been well studied, research has been primarily limited to cases in a single ecosystem. Our results indicate that there are differences in the flow of "1"3"7Cs through terrestrial and aquatic ecosystems, and that "1"3"7Cs concentrations are reduced in both basal food resources and higher trophic animals in aquatic systems, where primary production is subsidized by a neighboring terrestrial ecosystem. - Highlights: • Detrital-based food web structure was observed in both forest and stream ecosystems. • The "1"3"7Cs concentration in litter was 4 times lower in stream than in forest. • The difference of "1"3"7Cs concentration in litter reflected in animal contamination. • "1"3"7Cs leaching from litter decreases contamination level of stream food web. - Leaching from litter in stream decreases "1"3"7Cs concentration in litter, and the contamination level of food web in stream ecosystem is lower than that in adjacent forest ecosystem.

  1. The Midwest Stream Quality Assessment—Influences of human activities on streams

    Science.gov (United States)

    Van Metre, Peter C.; Mahler, Barbara J.; Carlisle, Daren M.; Coles, James F.

    2018-04-16

    Healthy streams and the fish and other organisms that live in them contribute to our quality of life. Extensive modification of the landscape in the Midwestern United States, however, has profoundly affected the condition of streams. Row crops and pavement have replaced grasslands and woodlands, streams have been straightened, and wetlands and fields have been drained. Runoff from agricultural and urban land brings sediment and chemicals to streams. What is the chemical, physical, and biological condition of Midwestern streams? Which physical and chemical stressors are adversely affecting biological communities, what are their origins, and how might we lessen or avoid their adverse effects?In 2013, the U.S. Geological Survey (USGS) conducted the Midwest Stream Quality Assessment to evaluate how human activities affect the biological condition of Midwestern streams. In collaboration with the U.S. Environmental Protection Agency National Rivers and Streams Assessment, the USGS sampled 100 streams, chosen to be representative of the different types of watersheds in the region. Biological condition was evaluated based on the number and diversity of fish, algae, and invertebrates in the streams. Changes to the physical habitat and chemical characteristics of the streams—“stressors”—were assessed, and their relation to landscape factors and biological condition was explored by using mathematical models. The data and models help us to better understand how the human activities on the landscape are affecting streams in the region.

  2. Brain and behavioural lateralization in invertebrates.

    OpenAIRE

    Elisa eFrasnelli

    2013-01-01

    Traditionally, only humans were thought to exhibit brain and behavioural asymmetries, but several studies have revealed that most vertebrates are also lateralized. Recently, evidence of left-right asymmetries in invertebrates has begun to emerge, suggesting that lateralization of the nervous system may be a feature of simpler brains as well as more complex ones. Here I present some examples in invertebrates of sensory and motor asymmetries, as well as asymmetries in the nervous system. I illu...

  3. Brain and behavioral lateralization in invertebrates

    OpenAIRE

    Frasnelli, Elisa

    2013-01-01

    Traditionally, only humans were thought to exhibit brain and behavioral asymmetries, but several studies have revealed that most vertebrates are also lateralized. Recently, evidence of left–right asymmetries in invertebrates has begun to emerge, suggesting that lateralization of the nervous system may be a feature of simpler brains as well as more complex ones. Here I present some examples in invertebrates of sensory and motor asymmetries, as well as asymmetries in the nervous system. I illus...

  4. Evolution of transgenerational immunity in invertebrates

    OpenAIRE

    Pigeault, R.; Garnier, R.; Rivero, A.; Gandon, S.

    2016-01-01

    Over a decade ago, the discovery of transgenerational immunity in invertebrates shifted existing paradigms on the lack of sophistication of their immune system. Nonetheless, the prevalence of this trait and the ecological factors driving its evolution in invertebrates remain poorly understood. Here, we develop a theoretical host–parasite model and predict that long lifespan and low dispersal should promote the evolution of transgenerational immunity. We also predict that in species that produ...

  5. Correlation of Brunhes detrital-layer stratigraphy into the North Atlantic from Orphan Knoll (Labrador Sea)

    Science.gov (United States)

    Channell, J. E.; Hodell, D. A.; Romero, O. E.; Hillaire-Marcel, C.; de Vernal, A.; Stoner, J. S.; Mazaud, A.; Roehl, U.

    2011-12-01

    IODP Site U1302-U1303, on the SE flank of Orphan Knoll (Labrador Sea), has a record of detrital layers that extends through most of the Brunhes Chron. The age model is built by tandem matching of relative paleointensity (RPI) and oxygen isotope data (δ18O) from Neogloboquadrina pachyderma (sin.) to reference records, indicating a mean Brunhes sedimentation rate of 14 cm/kyr. Sedimentation back to marine isotope stage (MIS) 18 is characterized by detrital layers that are detected by higher than background gamma-ray attenuation (GRA) density, peaks in X-ray fluorescence (XRF) indicators for detrital carbonate (Ca/Sr) and detrital silicate (Si/Sr), an ice-rafted debris (IRD) proxy (>106 μm), magnetic susceptibility, and magnetic grain-size peaks. The age model enables correlation of Site U1302/03 to IODP Site U1308 (re-drill of DSDP Site 609) in the heart of the central Atlantic IRD belt where an age model and a similar set of detrital-layer proxies have already been derived. Ages of Heinrich layers H1, H2, H4, H5 and H6 are within ~2 kyr at the two sites (H0, H3 and H5a are not observed at Site U1308), and agree with previous work at Orphan Knoll within ~3 kyr. At Site U1308, Brunhes detrital layers are restricted to peak glacials and glacial terminations back to MIS16, however, these same proxies at Site U1302/03 indicate detrital layers distributed throughout the record in both glacial and most interglacial stages. At Site U1302/03, we distinguish Heinrich-type layers in glacial stages, which are associated with IRD (some of which have near-synchronous analogues at Site U1308), from detrital layers within interglacial stages manifested by multiple detrital layer proxies (including Ca/Sr) but usually not associated with IRD, that may be attributed to a distinct depositional process, namely drainage and debris-flow events funneled down the nearby NAMOC (North Atlantic Mid-Ocean Channel).

  6. Toll-like receptors of deuterostome invertebrates

    Directory of Open Access Journals (Sweden)

    Honoo eSatake

    2012-02-01

    Full Text Available Defensive systems against pathogens are responsible not only for survival or lifetime of an individual but also for the evolution of a species. Innate immunity is expected to be more important for invertebrates than mammals, given that adaptive immunity has not been acquired in the former. Toll-like receptors (TLRs have been shown to play a crucial role in host defense of pathogenic microbes in innate immunity of mammals. Recent genome-wide analyses have suggested that TLR or their related genes are conserved in invertebrates. In particular, numerous TLR-related gene candidates were detected in deuterostome invertebrates including a sea urchin (222 TLR-related gene candidates and amphioxus (72 TLR-related gene candidates. Molecular phylogenetic analysis verified that most of sea urchin or amphioxus TLR candidates are paralogous, suggesting that these organisms expanded TLR-related genes in a species-specific manner. In contrast, another deuterostome invertebrate, an ascidian, Ciona intestinalis, was found to possess only two TLR genes. Moreover, Ciona TLRs, Ci-TLR1 and -2, were shown to possess hybrid functionality of mammalian TLRs. Such functionality of Ci-TLRs could not be predicted by sequence comparison with vertebrate TLRs, indicating the confounding evolutionary lineages of deuterostome invertebrate TLRs or their candidates. In this review article, we present recent advances in studies of TLRs or their candidates of deuterostome invertebrates, and provide insight into an evolutionary process of TLRs.

  7. A method for evaluating basement exhumation histories from closure age distributions of detrital minerals

    International Nuclear Information System (INIS)

    Lovera, Oscar M.; Grove, Marty; Kimbrough, David L.; Abbott, Patrick L.

    1999-01-01

    We have developed a two-dimensional, thermokinetic model that predicts the closure age distributions of detrital minerals from pervasively intruded and differentially exhumed basement. Using this model, we outline a method to determine the denudation history of orogenic regions on the basis of closure age distributions in synorogenic to postorogenic forearc strata. At relatively high mean denudation rates of 0.5 km m.y.-1 sustained over millions of years, magmatic heating events have minimal influence upon the age distributions of detrital minerals such as K-feldspar that are moderately retentive of radiogenic Ar. At lower rates, however, the effects of batholith emplacement may be substantial. We have applied the approach to detrital K-feldspars from forearc strata derived from the deeply denuded Peninsular Ranges batholith (PRB). Agreement of the denudation history deduced from the detrital K-feldspar data with thermochronologic constraints from exposed PRB basement lead us to conclude that exhumation histories of magmatic arcs should be decipherable solely from closure age distributions of detrital minerals whose depositional age is known. (c) 1999 American Geophysical Union

  8. Stream systems.

    Science.gov (United States)

    Jack E. Williams; Gordon H. Reeves

    2006-01-01

    Restored, high-quality streams provide innumerable benefits to society. In the Pacific Northwest, high-quality stream habitat often is associated with an abundance of salmonid fishes such as chinook salmon (Oncorhynchus tshawytscha), coho salmon (O. kisutch), and steelhead (O. mykiss). Many other native...

  9. 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

  10. Long-term resource limitation reduces insect detritivore growth in a headwater stream

    Science.gov (United States)

    Brent R. Johnson; Wyatt F. Cross; J. Bruce Wallace

    2003-01-01

    We measured larval growth rates of 2 dominant stream detritivore groups to assess the mechanism underlying declines in invertebrate production following exclusion of terrestrial litter inputs to a forested headwater stream. Larval Tallaperla spp. (P1ecoptera:Peltoperlidae) were chosen as representative shredders and non-Tanypodinae Chironomidae (...

  11. Riparian influences on the biophysical characteristics of seston in headwater streams.

    Science.gov (United States)

    Scott R. Elliott; Robert J. Naiman; Peter A. Bisson

    2004-01-01

    Suspended particles (seston) in streams are an important source of nutrition for many invertebrates, forming a strong trophic link between plant and animal production. In forested regions the management of riparian corridors may alter alloehthonous and autochthonous contributions to streams, ultimately changing the biophysical characteristics of seston. This article...

  12. Stream Biodiversity: The Ghost of Land Use Past

    Science.gov (United States)

    H.E. Harding; J.S. Benfield; E.F. Bolstad; P.V. Helfman; E.B.D. Jones

    1998-01-01

    The influece of past land use on the present-day diversity of stream invertebrates and fish was investigated by comparing watersheds with different land-use history. Whole watershed land use in the 1950s was the best predictor of present-day diversity, whereas riparian land use and watershed land use in the 1990s were comparatively poor indicators. Our findings...

  13. Sediment composition mediated land use effects on lowland streams ecosystems

    NARCIS (Netherlands)

    Dos Reis Oliveira, P.C.; Kraak, M.H.S.; van der Geest, H.G.; Naranjo, S.; Verdonschot, P.F.M

    2018-01-01

    Despite the widely acknowledged connection between terrestrial and aquatic ecosystems, the contribution of runoff to the sediment composition in lowland stream deposition zones and the subsequent effects on benthic invertebrates remain poorly understood. The aim of this study was therefore to

  14. Consumer-resource stoichiometry in detritus-based streams

    Science.gov (United States)

    Wyatt F. Cross; Jonathan P. Benstead; Amy D. Rosemond; J. Bruce Wallace

    2003-01-01

    Stoichiometric relationships between consumers and resources in detritus-based ecosystems have received little attention, despite the importance of detritus in most food webs. We analysed carbon (C), nitrogen (N), and phosphorus (P) content of invertebrate consumers, and basal food resources in two forested headwater streams (one reference and the other nutrient-...

  15. Stream Evaluation

    Data.gov (United States)

    Kansas Data Access and Support Center — Digital representation of the map accompanying the "Kansas stream and river fishery resource evaluation" (R.E. Moss and K. Brunson, 1981.U.S. Fish and Wildlife...

  16. Climate change links fate of glaciers and an endemic alpine invertebrate

    Science.gov (United States)

    Muhlfeld, Clint C.; Giersch, J. Joseph; Hauer, F. Richard; Pederson, Gregory T.; Luikart, Gordon; Peterson, Douglas P.; Downs, Christopher C.; Fagre, Daniel B.

    2011-01-01

    Climate warming in the mid- to high-latitudes and high-elevation mountainous regions is occurring more rapidly than anywhere else on Earth, causing extensive loss of glaciers and snowpack. However, little is known about the effects of climate change on alpine stream biota, especially invertebrates. Here, we show a strong linkage between regional climate change and the fundamental niche of a rare aquatic invertebrate—themeltwater stonefly Lednia tumana—endemic toWaterton- Glacier International Peace Park, Canada and USA. L. tumana has been petitioned for listing under the U.S. Endangered Species Act due to climate-change-induced glacier loss, yet little is known on specifically how climate impacts may threaten this rare species and many other enigmatic alpine aquatic species worldwide. During 14 years of research, we documented that L. tumana inhabits a narrow distribution, restricted to short sections (∼500 m) of cold, alpine streams directly below glaciers, permanent snowfields, and springs. Our simulation models suggest that climate change threatens the potential future distribution of these sensitive habitats and persistence of L. tumana through the loss of glaciers and snowfields. Mountaintop aquatic invertebrates are ideal early warning indicators of climate warming in mountain ecosystems. Research on alpine invertebrates is urgently needed to avoid extinctions and ecosystem change.

  17. Pesticides from wastewater treatment plant effluents affect invertebrate communities.

    Science.gov (United States)

    Münze, Ronald; Hannemann, Christin; Orlinskiy, Polina; Gunold, Roman; Paschke, Albrecht; Foit, Kaarina; Becker, Jeremias; Kaske, Oliver; Paulsson, Elin; Peterson, Märit; Jernstedt, Henrik; Kreuger, Jenny; Schüürmann, Gerrit; Liess, Matthias

    2017-12-01

    We quantified pesticide contamination and its ecological impact up- and downstream of seven wastewater treatment plants (WWTPs) in rural and suburban areas of central Germany. During two sampling campaigns, time-weighted average pesticide concentrations (c TWA ) were obtained using Chemcatcher® passive samplers; pesticide peak concentrations were quantified with event-driven samplers. At downstream sites, receiving waters were additionally grab sampled for five selected pharmaceuticals. Ecological effects on macroinvertebrate structure and ecosystem function were assessed using the biological indicator system SPEAR pesticides (SPEcies At Risk) and leaf litter breakdown rates, respectively. WWTP effluents substantially increased insecticide and fungicide concentrations in receiving waters; in many cases, treated wastewater was the exclusive source for the neonicotinoid insecticides acetamiprid and imidacloprid in the investigated streams. During the ten weeks of the investigation, five out of the seven WWTPs increased in-stream pesticide toxicity by a factor of three. As a consequence, at downstream sites, SPEAR values and leaf litter degradation rates were reduced by 40% and 53%, respectively. The reduced leaf litter breakdown was related to changes in the macroinvertebrate communities described by SPEAR pesticides and not to altered microbial activity. Neonicotinoids showed the highest ecological relevance for the composition of invertebrate communities, occasionally exceeding the Regulatory Acceptable Concentrations (RACs). In general, considerable ecological effects of insecticides were observed above and below regulatory thresholds. Fungicides, herbicides and pharmaceuticals contributed only marginally to acute toxicity. We conclude that pesticide retention of WWTPs needs to be improved. Copyright © 2017 Elsevier B.V. All rights reserved.

  18. Wood decomposition as influenced by invertebrates.

    Science.gov (United States)

    Ulyshen, Michael D

    2016-02-01

    The diversity and habitat requirements of invertebrates associated with dead wood have been the subjects of hundreds of studies in recent years but we still know very little about the ecological or economic importance of these organisms. The purpose of this review is to examine whether, how and to what extent invertebrates affect wood decomposition in terrestrial ecosystems. Three broad conclusions can be reached from the available literature. First, wood decomposition is largely driven by microbial activity but invertebrates also play a significant role in both temperate and tropical environments. Primary mechanisms include enzymatic digestion (involving both endogenous enzymes and those produced by endo- and ectosymbionts), substrate alteration (tunnelling and fragmentation), biotic interactions and nitrogen fertilization (i.e. promoting nitrogen fixation by endosymbiotic and free-living bacteria). Second, the effects of individual invertebrate taxa or functional groups can be accelerative or inhibitory but the cumulative effect of the entire community is generally to accelerate wood decomposition, at least during the early stages of the process (most studies are limited to the first 2-3 years). Although methodological differences and design limitations preclude meta-analysis, studies aimed at quantifying the contributions of invertebrates to wood decomposition commonly attribute 10-20% of wood loss to these organisms. Finally, some taxa appear to be particularly influential with respect to promoting wood decomposition. These include large wood-boring beetles (Coleoptera) and termites (Termitoidae), especially fungus-farming macrotermitines. The presence or absence of these species may be more consequential than species richness and the influence of invertebrates is likely to vary biogeographically. Published 2014. This article is a U.S. Government work and is in the public domain in the USA.

  19. Accumulation of 210Po in Baltic invertebrates

    International Nuclear Information System (INIS)

    Skwarzec, B.; Falkowski, L.

    1988-01-01

    This paper presents the results of an investigation of the 210 Po contents of Baltic marine invertebrates. The 210 Po concentrations fall within the range 11.3-78.9 Bq kg -1 (dry wt), the higher values relating to polychaeta, priapulida and malacostraca and the lower levels to bivalvia. It is demonstrated that 210 Po is non-uniformly distributed within the isopod Mesidotea entomon and the bivalve Mya arenaria. The 210 Po contents of the internal organs decreasing in the order-hepatopancreas > alimentary tract > gill > muscle. Moreover, the results indicate the dominant role of the digestive organs of these invertebrates in controlling absorption and elimination of 210 Po. (author)

  20. Brown trout and food web interactions in a Minnesota stream

    Science.gov (United States)

    Zimmerman, J.K.H.; Vondracek, B.

    2007-01-01

    1. We examined indirect, community-level interactions in a stream that contained non-native brown trout (Salmo trutta Linnaeus), native brook trout (Salvelinus fontinalis Mitchill) and native slimy sculpin (Cottus cognatus Richardson). Our objectives were to examine benthic invertebrate composition and prey selection of fishes (measured by total invertebrate dry mass, dry mass of individual invertebrate taxa and relative proportion of invertebrate taxa in the benthos and diet) among treatments (no fish, juvenile brook trout alone, juvenile brown trout alone, sculpin with brook trout and sculpin with brown trout). 2. We assigned treatments to 1 m2 enclosures/exclosures placed in riffles in Valley Creek, Minnesota, and conducted six experimental trials. We used three designs of fish densities (addition of trout to a constant number of sculpin with unequal numbers of trout and sculpin; addition of trout to a constant number of sculpin with equal numbers of trout and sculpin; and replacement of half the sculpin with an equal number of trout) to investigate the relative strength of interspecific versus intraspecific interactions. 3. Presence of fish (all three species, alone or in combined-species treatments) was not associated with changes in total dry mass of benthic invertebrates or shifts in relative abundance of benthic invertebrate taxa, regardless of fish density design. 4. Brook trout and sculpin diets did not change when each species was alone compared with treatments of both species together. Likewise, we did not find evidence for shifts in brown trout or sculpin diets when each species was alone or together. 5. We suggest that native brook trout and non-native brown trout fill similar niches in Valley Creek. We did not find evidence that either species had an effect on stream communities, potentially due to high invertebrate productivity in Valley Creek. ?? 2007 Blackwell Publishing Ltd.

  1. Effects of water removal on a Hawaiian stream ecosystem

    Science.gov (United States)

    Kinzie, R. A.; Chong, C.; Devrell, J.; Lindstrom, D.; Wolff, R.

    2006-01-01

    A 3-year study of Wainiha River on Kaua'i, Hawai'i, was carried out to determine the impact that water removal had on key stream ecosystem parameters and functions. The study area included a diversion dam for a hydroelectric plant that removes water at an elevation of 213 m and returns it to the stream about 6 km downstream at an elevation of 30 m. There were two high-elevation sites, one with undiverted flow and one with reduced flow, and two low-elevation sites, one with reduced flow and one with full flow restored. Monthly samples were taken of instream and riparian invertebrates and plants. When samples from similar elevations were compared, dewatered sites had lower concentrations of benthic photosynthetic pigments than full-flow sites, and benthic ash-free dry mass (AFDM) was higher at the two low-elevation sites regardless of flow. Benthic chlorophyll a (chl a) and AFDM were higher in summer months than in the winter. Benthic invertebrate abundance was highest at the full-flow, low-elevation site and benthic invertebrate biomass was highest at the full-flow, high-elevation site. Season had only marginal effects on abundance and biomass of benthic invertebrates. Diversity of benthic invertebrates was higher at the more-downstream sites. Abundance of drifting invertebrates was highest at the site above the diversion dam and generally higher in winter than in summer months. Biomass of drifting invertebrates was also highest at the above-dam site but there was little seasonal difference. Almost all parameters measured were lowest at the site just downstream of the diversion dam. The biotic parameters responded only weakly to flows that had occurred up to 1 month before the measurements were made. Flow, elevation, and season interact in complex ways that impact ecosystem parameters and functions, but water diversion can override all these environmental factors. ?? 2006 by University of Hawai'i Press All rights reserved.

  2. Biological responses to acidification reversal in Cumbrian streamwaters - stream water chemistry

    Energy Technology Data Exchange (ETDEWEB)

    Tipping, E.; Hardie, D.J.; Lawlor, A.J.; Lofts, S.; Simon, B.M.; Vincent, C.D. [Institute of Freshwater Ecology, Ambleside (United Kingdom)

    1999-07-01

    This reports summarises the findings of a study sampling the streams for invertebrates and comparing the results with those made in the 1960s and 1970s, The distribution of the bacterium Cytophaga was examined, and the results of the chemical analysis of the stream waters were compared with the results from previous years. The background to the study is traced, and details of the sampling and chemical analysis are given. Evidence of the reversal of acidification in the streams is considered.

  3. Contribution to the study of the biodiversity of benthic invertebrates ...

    African Journals Online (AJOL)

    Contribution to the study of the biodiversity of benthic invertebrates and the biological quality of some rivers in the watershed boumerzoug (east of Algeria) ... benthic macro invertebrates, allows characterizing the biological quality of river water.

  4. HISTOLOGICAL PREPARATION OF INVERTEBRATES FOR EVALUATING CONTAMINANT EFFECTS

    Science.gov (United States)

    Although many studies in toxicologic pathology evaluate the effects of toxicants on fishes because of their similarities with other vertebrates, invertebrates can also provide insights into toxicant impacts on ecosystems. Invertebrates not only serve as food resources (e.g., ...

  5. Effects on water chemistry, benthic invertebrates and brown trout following forest fertilization in central Sweden

    International Nuclear Information System (INIS)

    Goethe, L.; Soederberg, H.; Sjoelander, E.

    1993-01-01

    Two coniferous forest drainage areas in central Sweden were partially fertilized with ammonium nitrate and calcium ammonium nitrate respectively, both at a dose of 150 kg N per ha. During the following years observations were made on stream water chemistry, invertebrates and brown trout (Salmo trutta L.). Upstream stations were used as controls. Very high concentrations of inorganic N (up to 45 mg l -1 ) were recorded immediately after the fertilization. Thereafter, concentration decreased rapidly but remained elevated during the whole study period. Acidity conditions (pH, alkalinity, aluminium) were unaffected by both treatments. The only registered effect on the benthic fauna was a three- to five-fold increase of drifting invertebrates during the first four-five days after the treatment. However, this did not reduce the population density at the treated stations. No effects on population of trout were recorded. (22 refs., 6 figs., 3 tabs.)

  6. Biogenic magnetite, detrital hematite, and relative paleointensity in Quaternary sediments from the Southwest Iberian Margin

    Science.gov (United States)

    Channell, J. E. T.; Hodell, D. A.; Margari, V.; Skinner, L. C.; Tzedakis, P. C.; Kesler, M. S.

    2013-08-01

    Magnetic properties of late Quaternary sediments on the SW Iberian Margin are dominated by bacterial magnetite, observed by transmission electron microscopy (TEM), with contributions from detrital titanomagnetite and hematite. Reactive hematite, together with low organic matter concentrations and the lack of sulfate reduction, lead to dissimilatory iron reduction and availability of Fe(II) for abundant magnetotactic bacteria. Magnetite grain-size proxies (κARM/κ and ARM/IRM) and S-ratios (sensitive to hematite) vary on stadial/interstadial timescales, contain orbital power, and mimic planktic δ18O. The detrital/biogenic magnetite ratio and hematite concentration are greater during stadials and glacial isotopic stages, reflecting increased detrital (magnetite) input during times of lowered sea level, coinciding with atmospheric conditions favoring hematitic dust supply. Magnetic susceptibility, on the other hand, has a very different response being sensitive to coarse detrital multidomain (MD) magnetite associated with ice-rafted debris (IRD). High susceptibility and/or magnetic grain-size coarsening, mark Heinrich stadials (HS), particularly HS2, HS3, HS4, HS5, HS6 and HS7, as well as older Heinrich-like detrital layers, indicating the sensitivity of this region to fluctuations in the position of the polar front. Relative paleointensity (RPI) records have well-constrained age models based on planktic δ18O correlation to ice-core chronologies, however, they differ from reference records (e.g. PISO) particularly in the vicinity of glacial maxima, mainly due to inefficient normalization of RPI records in intervals of enhanced hematite input.

  7. 76 FR 61379 - Final Recovery Plan, Bexar County Karst Invertebrates

    Science.gov (United States)

    2011-10-04

    ...] Final Recovery Plan, Bexar County Karst Invertebrates AGENCY: Fish and Wildlife Service, Interior... availability of our final recovery plan, for the nine Bexar County Karst Invertebrates under the Endangered... County karst invertebrates were listed as endangered species on December 26, 2000 (65 FR 81419): Rhadine...

  8. A new estimate of detrital redox-sensitive metal concentrations and variability in fluxes to marine sediments

    Science.gov (United States)

    Cole, Devon B.; Zhang, Shuang; Planavsky, Noah J.

    2017-10-01

    The enrichment and depletion of redox sensitive trace metals in marine sediments have been used extensively as paleoredox proxies. The trace metals in shale are comprised of both detrital (transported or particulate) and authigenic (precipitated, redox-driven) constituents, potentially complicating the use of this suite of proxies. Untangling the influence of these components is vital for the interpretation of enrichments, depletions, and isotopic signals of iron (Fe), chromium (Cr), uranium (U), and vanadium (V) observed in the rock record. Traditionally, a single crustal average is used as a cutoff for detrital input, and concentrations above or below this value are interpreted as redox derived authigenic enrichment or depletion, while authigenic isotopic signals are frequently corrected for an assumed detrital contribution. Building from an extensive study of soils across the continental United States - which upon transport will become marine sediments - and their elemental concentrations, we find large deviations from accepted crustal averages in redox-sensitive metals (Fe, Cr, U, V) compared to typical detrital tracers (Al, Ti, Sc, Th) and provide new estimates for detrital contributions to the ocean. The variability in these elemental ratios is present over large areas, comparable to the catchment-size of major rivers around the globe. This heterogeneity in detrital flux highlights the need for a reevaluation of how the detrital contribution is assessed in trace metal studies, and the use of confidence intervals rather than single average values, especially in local studies or in the case of small authigenic enrichments.

  9. Lanthanides, thorium, iodine in terrestrail invertebrates

    International Nuclear Information System (INIS)

    Zhulidov, A.V.; Pokarzhevskij, A.D.; Katargin, N.V.; AN SSSR, Moscow

    1991-01-01

    It is shown that among examined terrestrial invertebrates the highest levels on lanthanide and thorium concentration are typical for animals, feeding on plant tissues - earthworms, molluscs, diploid. It is shown that there are no reasons to hope, that regularities of migration of transuranium elements and lanthanides in tropic chains are identical

  10. Roebuck Bay Invertebrate and bird Mapping 2006

    NARCIS (Netherlands)

    Piersma, Theunis; Pearson, Grant B.; Hickey, Robert; Dittmann, Sabine; Rogers, Danny I.; Folmer, Eelke; Honkoop, Pieter; Drent, Jan; Goeij, Petra de; Marsh, Loisette

    2006-01-01

    1. This is a report on a survey of the benthic ecology of the intertidal flats along the northern shores of Roebuck Bay in June 2006. In the period 11-20 June we mapped both the invertebrate macrobenthic animals (those retained by a 1 mm sieve) over the whole of the northern intertidal area of

  11. Evolution of transgenerational immunity in invertebrates.

    Science.gov (United States)

    Pigeault, R; Garnier, R; Rivero, A; Gandon, S

    2016-09-28

    Over a decade ago, the discovery of transgenerational immunity in invertebrates shifted existing paradigms on the lack of sophistication of their immune system. Nonetheless, the prevalence of this trait and the ecological factors driving its evolution in invertebrates remain poorly understood. Here, we develop a theoretical host-parasite model and predict that long lifespan and low dispersal should promote the evolution of transgenerational immunity. We also predict that in species that produce both philopatric and dispersing individuals, it may pay to have a plastic allocation strategy with a higher transgenerational immunity investment in philopatric offspring because they are more likely to encounter locally adapted pathogens. We review all experimental studies published to date, comprising 21 invertebrate species in nine different orders, and we show that, as expected, longevity and dispersal correlate with the transfer of immunity to offspring. The validity of our prediction regarding the plasticity of investment in transgenerational immunity remains to be tested in invertebrates, but also in vertebrate species. We discuss the implications of our work for the study of the evolution of immunity, and we suggest further avenues of research to expand our knowledge of the impact of transgenerational immune protection in host-parasite interactions. © 2016 The Author(s).

  12. Bromeliads in Caatinga: an oasis for invertebrates

    Directory of Open Access Journals (Sweden)

    Priscila Islair

    2014-11-01

    Full Text Available http://dx.doi.org/10.5007/2175-7925.2015v28n1p67 The Bromeliaceae family exhibits several adaptations that allow the occurrence of its members in different physiognomies, including the Caatinga. The arrangement of leaves in rosette forms a cistern or tank, in which nutrient-rich water accumulates. This provides a microhabitat for reproduction, feeding, and larval development of many invertebrates. The aim of this study was to survey the bromeliad-associated invertebrate fauna to test the hypothesis of seasonal changes in community composition. We conducted two surveys in the rainy (February, 2011 and dry (August, 2012 seasons in the Floresta Nacional (Flona of Contendas do Sincorá, municipality of Contendas do Sincorá, Bahia state, Brazil. We delimited fifteen 5 m x 5 m sampling plots along a 355 m trail. Two terrestrial bromeliads (Aechmea bromeliifolia were collected per plot. Invertebrate fauna were identified and richness, abundance and composition were analyzed. The richness of taxa did not differ between seasons and was considered high for Caatinga. Abundance and composition differed between the rainy and dry seasons. The present study demonstrates the importance of bromeliads as available water resources for the local invertebrate community. Our findings also provide a framework for more in-depth studies on animal-plant interactions, and for the conservation of Caatinga animals and plants.

  13. Bromeliads in Caatinga: an oasis for invertebrates

    Directory of Open Access Journals (Sweden)

    Priscila Islair

    2015-02-01

    Full Text Available The Bromeliaceae family exhibits several adaptations that allow the occurrence of its members in different physiognomies, including the Caatinga. The arrangement of leaves in rosette forms a cistern or tank, in which nutrient-rich water accumulates. This provides a microhabitat for reproduction, feeding, and larval development of many invertebrates. The aim of this study was to survey the bromeliad-associated invertebrate fauna to test the hypothesis of seasonal changes in community composition. We conducted two surveys in the rainy (February, 2011 and dry (August, 2012 seasons in the Floresta Nacional (Flona of Contendas do Sincorá, municipality of Contendas do Sincorá, Bahia state, Brazil. We delimited fifteen 5 m x 5 m sampling plots along a 355 m trail. Two terrestrial bromeliads (Aechmea bromeliifolia were collected per plot. Invertebrate fauna were identified and richness, abundance and composition were analyzed. The richness of taxa did not differ between seasons and was considered high for Caatinga. Abundance and composition differed between the rainy and dry seasons. The present study demonstrates the importance of bromeliads as available water resources for the local invertebrate community. Our findings also provide a framework for more in-depth studies on animal-plant interactions, and for the conservation of Caatinga animal and plant.

  14. Detrital zircon ages from southern Norway - implications for the Proterozoic evolution of the southwestern Baltic Shield

    Science.gov (United States)

    Knudsen, T.-L.; Andersen, T.; Whitehouse, M. J.; Vestin, J.

    An ion-microprobe (SIMS) U-Pb zircon dating study on four samples of Precambrian metasediments from the high-grade Bamble Sector, southern Norway, gives the first information on the timing of discrete crust-forming events in the SW part of the Baltic Shield. Recent Nd and Pb studies have indicated that the sources of the clastic metasediments in this area have crustal histories extending back to 1.7 to 2.1Ga, although there is no record of rocks older than 1.6Ga in southern Norway. The analysed metasediments are from a sequence of intercalated, centimetre to 10-metre wide units of quartzites, semi-metapelites, metapelites and mafic granulites. The zircons can be grouped in two morphological populations: (1) long prismatic; (2) rounded, often flattened. The BSE images reveal that both populations consist of oscillatory zoned, rounded and corroded cores (detrital grains of magmatic origin), surrounded by homogeneous rims (metamorphic overgrowths). The detrital zircons have 207Pb/206Pb ages between 1367 and 1939Ma, with frequency maxima in the range 1.85 to 1.70Ga and 1.60 to 1.50Ga. There is no correlation between crystal habit and age of the zircon. One resorbed, inner zircon core in a detrital grain is strongly discordant and gives a composite inner core-magmatic outer core 207Pb/206Pb age of 2383 Ma. Two discrete, unzoned zircons have 207Pb/206Pb ages of 1122 and 1133Ma, representing zircon growth during the Sveconorwegian high-grade metamorphism. Also the μm wide overgrowths, embayments in the detrital cores and apparent ``inner cores'' which represent secondary metamorphic zircon growth in deep embayments in detrital grains, are of Sveconorwegian age. The composite-detrital-metamorphic zircon analyses give generally discordant 206Pb/238U versus 207Pb/235U ratios and maximum 207Pb/206Pb ages of 1438Ma. These data demonstrate the existence of a protocrust of 1.7 to 2.0Ga in the southwestern part of the Baltic Shield, implying a break in the overall westward

  15. Detrital K-feldspar thermochronology of the Nanaimo Group: Characterization of Basement and Extraregional Basin Contributions

    Science.gov (United States)

    Isava, V.; Grove, M.; Mahoney, J. B.; Kimbrough, D. L.

    2016-12-01

    The Late Cretaceous-Early Paleogene Nanaimo Group covers the contact between Triassic basement Wrangellia terrane and the Jurassic-Cretaceous Coast Plutonic Complex (CPC) in southern British Columbia. Prior detrital zircon U-Pb and Hf studies indicate a change in sediment source for the Nanaimo basin, from the primitive CPC in Santonian-Early Campanian time to an isotopically evolved continental extraregional source during the late Campanian/Maastrictian. Two notably different areas have been proposed as potential source regions: (1) the Idaho/Boulder batholith and Belt Supergroup, and (2) the Mojave/Salinia segment of structurally disrupted late Cretaceous southern California margin. Single crystal 40Ar/39Ar laser fusion of ca. 100-200 grains apiece from seven detrital K-feldspar samples from Santonian-Maastrichtian strata of the northern Nanaimo Group constrain the history of the sediments' source regions. The two oldest samples, from the K-feldspar poor Comox and Extension Fms., display a monotonic increasing distribution of cooling ages 80-125 Ma that reflects shallow erosion of the CPC. In contrast, Late Campanian strata of the Cedar District and De Courcy Fms. exhibit a more pronounced cluster of cooling ages 80-95 Ma as well as a greater proportion of Jurassic ages that represent progressively deeper erosion of the CPC. Evidence for an extraregional sediment source appears abruptly in the Geoffrey Fm. by 72 Ma, matching the time of local-to-extraregional shift indicated in detrital zircon U-Pb studies. Over 90% of the detrital K-feldspars from these arkosic sandstones yield cooling ages of 70-80 Ma, with sparse older ages associated with the CPC. Samples from the successively younger Spray and Gabriola Fms. also yield >90% K-feldspar ages younger than 80 Ma and exhibit age maxima of 68 Ma and 65 Ma, respectively. These results are distinct from detrital zircon U-Pb and K-feldspar 40Ar/39Ar ages of the southern Sierra Nevada, Mojave/Salina, and northern

  16. Invertebrates associated with ipomea aquatica in ogbe creek, logos, nigeria

    International Nuclear Information System (INIS)

    Saliu, J.K.; Fashola, Y.T.

    2006-01-01

    The association of invertebrates in Ogbe creek with Ipomea aquatica was investigated within the period from 7th September to 30th November, 2001, 167 invertebrates comprising of 19 species were harvested from 73 weeds. Corixa punctata (22.16%) was the most abundant invertebrate on Ipomea aquatica while Gyrinus notator larvae (0.60%) were the least abundant. The roots sheltered the highest number of invertebrates (113), comprising of 12 species recording a species diversity of 5.36 while the stem sheltered the lowest number of invertebrates (10) comprising of 3 species with a species diversity of 2.00. The ability of Ipomea aquaTica to harbour invertebrates was influenced by the morphological form of the plant. The root was the preferred site for the invertebrates because it was a suitable substrate for clinging and nutrient supply. (author)

  17. Aquatic invertebrates of the Ribnica and Lepenica Rivers: Composition of the community and water quality

    Directory of Open Access Journals (Sweden)

    Jović Aleksandra

    2006-01-01

    Full Text Available Results of investigating the community of aquatic invertebrates in the Ribnica and Lepenica Rivers (Kolubara River drainage area are given in the present work. Forty-three taxa are recorded. In relation to other studied streams in Serbia, the investigated rivers are characterized by high diversity of macroinvertebrates. Cluster analysis indicates that the locality on the Lepenica stands apart from those on the Ribnica, which is a consequence of the difference of habitats found at them. Results of saprobiological analysis of the macrozoobenthos in the given rivers indicate that their waters belong to quality classes I and II.

  18. Global pressures, specific responses: effects of nutrient enrichment in streams from different biomes

    International Nuclear Information System (INIS)

    Artigas, Joan; García-Berthou, Emili; Gómez, Nora; Romaní, Anna M; Sabater, Sergi; Bauer, Delia E; Cochero, Joaquín; Cortelezzi, Agustina; Rodrigues-Capítulo, Alberto; Castro, Maria I; Donato, John C; Colautti, Darío C; Elosegi, Arturo; Feijoó, Claudia; Giorgi, Adonis; Leggieri, Leonardo; Muñoz, Isabel

    2013-01-01

    We assessed the effects of nutrient enrichment on three stream ecosystems running through distinct biomes (Mediterranean, Pampean and Andean). We increased the concentrations of N and P in the stream water 1.6–4-fold following a before–after control–impact paired series (BACIPS) design in each stream, and evaluated changes in the biomass of bacteria, primary producers, invertebrates and fish in the enriched (E) versus control (C) reaches after nutrient addition through a predictive-BACIPS approach. The treatment produced variable biomass responses (2–77% of explained variance) among biological communities and streams. The greatest biomass response was observed for algae in the Andean stream (77% of the variance), although fish also showed important biomass responses (about 9–48%). The strongest biomass response to enrichment (77% in all biological compartments) was found in the Andean stream. The magnitude and seasonality of biomass responses to enrichment were highly site specific, often depending on the basal nutrient concentration and on windows of ecological opportunity (periods when environmental constraints other than nutrients do not limit biomass growth). The Pampean stream, with high basal nutrient concentrations, showed a weak response to enrichment (except for invertebrates), whereas the greater responses of Andean stream communities were presumably favored by wider windows of ecological opportunity in comparison to those from the Mediterranean stream. Despite variation among sites, enrichment globally stimulated the algal-based food webs (algae and invertebrate grazers) but not the detritus-based food webs (bacteria and invertebrate shredders). This study shows that nutrient enrichment tends to globally enhance the biomass of stream biological assemblages, but that its magnitude and extent within the food web are complex and are strongly determined by environmental factors and ecosystem structure. (letter)

  19. Detrital zircon geochronology and provenance of the Chubut Group in the northeast of Patagonia, Argentina

    Science.gov (United States)

    Navarro, Edgardo L.; Astini, Ricardo A.; Belousova, Elena; Guler, M. Verónica; Gehrels, George

    2015-11-01

    The Chubut Group constitutes the most widespread sedimentary unit in NE Patagonia, characterized by variable-energy fluvial deposits. U-Pb analysis of detrital zircons from two sections of the Chubut Group constraint the age of the oldest sedimentary rocks in the northeast of the Somuncurá - Cañadón Asfalto Basin. In the Cañadón Williams area, at San Jorge section, 20 km NW of Telsen locality, dating of 56 detrital zircons from a medium to coarse sandstone indicated a maximum depositional age of 109 ± 1 Ma (n = 4). These sandstones were interpreted to represent shallow channels, associated with a lacustrine system. In the Telsen locality, a laser ablation analysis of 115 detrital zircons from a medium to coarse-grained sandstone, from fluvial channel facies, yielded a maximum depositional age of ca. 106 ± 1 Ma (n = 8). Both ages are consistent with volcanic events of the Barremian to Albian age in the central Patagonian Andes Region. Cathodoluminescence images of zircons from the San Jorge sample suggest an igneous origin, which is further supported by Th/U values above 0.5 in most of the grains. The distribution of the statistical modes of the main age populations of detrital zircons for the two samples [182, 185 and 189 Ma for Telsen sample (T2S) and 181 ± 1 Ma for San Jorge sample (SJS)] matches the age of the volcanic Marifil Formation. The rocks of the Marifil Formation of these ages are exposed NE to SE of the study area. The abundance of zircons of similar Jurassic ages (n = 52 for SJS and n = 105 for T2S) and the external morphology of the zircons in the sample SJS, implies a close proximity of the source area. Suggestion that the Marifil Formation was the main provenance source is also supported by northeast-southeasterly paleocurrents measured at the San Jorge and Telsen sections.

  20. Detrital illite crystals identified from crystallite thickness measurements in siliciclastic sediments

    Science.gov (United States)

    Aldega, L.; Eberl, D.D.

    2005-01-01

    Illite crystals in siliciclastic sediments are heterogeneous assemblages of detrital material coming from various source rocks and, at paleotemperatures >70 ??C, of superimposed diagenetic modification in the parent sediment. We distinguished the relative proportions of 2M1 detrital illite and possible diagenetic 1Md + 1M illite by a combined analysis of crystal-size distribution and illite polytype quantification. We found that the proportions of 1Md + 1M and 2M1 illite could be determined from crystallite thickness measurements (BWA method, using the MudMaster program) by unmixing measured crystallite thickness distributions using theoretical and calculated log-normal and/or asymptotic distributions. The end-member components that we used to unmix the measured distributions were three asymptotic-shaped distributions (assumed to be the diagenetic component of the mixture, the 1Md + 1M polytypes) calculated using the Galoper program (Phase A was simulated using 500 crystals per cycle of nucleation and growth, Phase B = 333/cycle, and Phase C = 250/ cycle), and one theoretical log-normal distribution (Phase D, assumed to approximate the detrital 2M1 component of the mixture). In addition, quantitative polytype analysis was carried out using the RockJock software for comparison. The two techniques gave comparable results (r2 = 0.93), which indicates that the unmixing method permits one to calculate the proportion of illite polytypes and, therefore, the proportion of 2M1 detrital illite, from crystallite thickness measurements. The overall illite crystallite thicknesses in the samples were found to be a function of the relative proportions of thick 2M1 and thin 1Md + 1M illite. The percentage of illite layers in I-S mixed layers correlates with the mean crystallite thickness of the 1Md + 1M polytypes, indicating that these polytypes, rather than the 2M1 polytype, participate in I-S mixed layering.

  1. Groundwater budgets for Detrital, Hualapai, and Sacramento Valleys, Mohave County, Arizona, 2007-08

    Science.gov (United States)

    Garner, Bradley D.; Truini, Margot

    2011-01-01

    The United States Geological Survey, in cooperation with the Arizona Department of Water Resources, initiated an investigation of the hydrogeology and water resources of Detrital, Hualapai, and Sacramento Valleys in northwestern Arizona in 2005, and this report is part of that investigation. Water budgets were developed for Detrital, Hualapai, and Sacramento Valleys to provide a generalized understanding of the groundwater systems in this rural area that has shown some evidence of human-induced water-level declines. The valleys are within the Basin and Range physiographic province and consist of thick sequences of permeable alluvial sediment deposited into basins bounded by relatively less permeable igneous and metamorphic rocks. Long-term natural recharge rates (1940-2008) for the alluvial aquifers were estimated to be 1,400 acre-feet per year (acre-ft/yr) for Detrital Valley, 5,700 acre-ft/yr for Hualapai Valley, and 6,000 acre-ft/yr for Sacramento Valley. Natural discharge rates were assumed to be equal to natural recharge rates, on the basis of the assumption that all groundwater withdrawals to date have obtained water from groundwater storage. Groundwater withdrawals (2007-08) for the alluvial aquifers were less than 300 acre-ft/yr for Detrital Valley, about 9,800 acre-ft/yr for Hualapai Valley, and about 4,500 acre-ft/yr for Sacramento Valley. Incidental recharge from leaking water-supply pipes, septic systems, and wastewater-treatment plants accounted for about 35 percent of total recharge (2007-08) across the study area. Natural recharge and discharge values in this study were 24-50 percent higher than values in most previously published studies. Water budgets present a spatially and temporally "lumped" view of water resources and incorporate many sources of uncertainty in this study area where only limited data presently are available.

  2. The Origin of DIRT (Detrital Input and Removal Treatments): the Legacy of Dr. Francis D. Hole

    Science.gov (United States)

    Townsend, K. L.; Lajtha, K.; Caldwell, B.; Sollins, P.

    2007-12-01

    Soil organic matter (SOM) plays a key role in the cycling and retention of nitrogen and carbon within soil. Both above and belowground detrital inputs determine the nature and quantity of SOM. Studies on detrital impacts on SOM dynamics are underway at several LTER, ILTER and LTER-affiliated sites using a common experimental design, Detrital Input and Removal Treatments (DIRT). The concept for DIRT was originally based on experimental plots established at the University of Wisconsin Arboretum by Dr. Francis D. Hole in 1956 to study the effects of detrital inputs on pedogenesis. These plots are located on two forested sites and two prairie sites within the arboretum. Manipulations of the forested sites include double litter, no litter and removal of the O and A horizons. Manipulations of the prairie sites include harvest, mulch, bare and burn. These original treatments have largely been maintained since 1956. After 40 years of maintenance, there were significant differences in soil carbon between the double and no litter plots. The double litter plots had increased by nearly 30% while the no litter plots had decreased over 50%. The original DIRT plots are now 50 years old and have been re-sampled, where possible, for total carbon and nitrogen, labile and recalcitrant carbon fractions, net and gross nitrogen mineralization rates, and SOM bioavailability through CO2 respiration. The soils were fractionated by density to examine the role of carbon in each density fraction. The mean age of carbon in each fraction was determined by radiocarbon dating. This sampling and analysis is of special significance because it provides a glimpse into the future SOM trajectories for the new DIRT sites: Harvard Forest (MA), Bousson (PA), Andrews Experimental Forest (OR) and Sikfokut (Hungary).

  3. Enzyme Histochemistry for Functional Histology in Invertebrates.

    Science.gov (United States)

    Cima, Francesca

    2017-01-01

    In invertebrates, enzyme histochemistry has recently found a renaissance regarding its applications in morphology and ecology. Many enzyme activities are useful for the morphofunctional characterization of cells, as biomarkers of biological and pathologic processes, and as markers of the response to environmental stressors. Here, the adjustments to classic techniques, including the most common enzymes used for digestion, absorption, transport, and oxidation, as well as techniques for azo-coupling, metal salt substitution and oxidative coupling polymerization, are presented in detail for various terrestrial and aquatic invertebrates. This chapter also provides strategies to solve the problems regarding anesthesia, small body size, the presence of an exo- or endoskeleton and the search for the best fixative in relation to the internal fluid osmolarity. These techniques have the aim of obtaining good results for both the pre- and post-embedding labeling of specimens, tissue blocks, sections, and hemolymph smears using both light and transmission electron microscopy.

  4. Ethics and invertebrates: a cephalopod perspective.

    Science.gov (United States)

    Mather, Jennifer A; Anderson, Roland C

    2007-05-04

    This paper first explores 3 philosophical bases for attitudes to invertebrates, Contractarian/Kantian, Utilitarian, and Rights-based, and what they lead us to conclude about how we use and care for these animals. We next discuss the problems of evaluating pain and suffering in invertebrates, pointing out that physiological responses to stress are widely similar across the animal kingdom and that most animals show behavioral responses to potentially painful stimuli. Since cephalopods are often used as a test group for consideration of pain, distress and proper conditions for captivity and handling, we evaluate their behavioral and cognitive capacities. Given these capacities, we then discuss practical issues: minimization of their pain and suffering during harvesting for food; ensuring that captive cephalopods are properly cared for, stimulated and allowed to live as full a life as possible; and, lastly, working for their conservation.

  5. Effects of nanomaterials on marine invertebrates.

    Science.gov (United States)

    Canesi, Laura; Corsi, Ilaria

    2016-09-15

    The development of nanotechnology will inevitably lead to the release of consistent amounts of nanomaterials (NMs) and nanoparticles (NPs) into marine ecosystems. Ecotoxicological studies have been carried out to identify potential biological targets of NPs, and suitable models for predicting their impact on the health of the marine environment. Recent studies in invertebrates mainly focused on NP accumulation and sub-lethal effects, rather than acute toxicity. Among marine invertebrates, bivalves represent by large the most studied group, with polychaetes and echinoderms also emerging as significant targets of NPs. However, major scientific gaps still need to be filled. In this work, factors affecting the fate of NPs in the marine environment, and their consequent uptake/accumulation/toxicity in marine invertebrates will be summarized. The results show that in different model species, NP accumulation mainly occurs in digestive tract and gills. Data on sub-lethal effects and modes of action of different types of NPs (mainly metal oxides and metal based NPs) in marine invertebrates will be reviewed, in particular on immune function, oxidative stress and embryo development. Moreover, the possibility that such effects may be influenced by NP interactions with biomolecules in both external and internal environment will be introduced. In natural environmental media, NP interactions with polysaccharides, proteins and colloids may affect their agglomeration/aggregation and consequent bioavailability. Moreover, once within the organism, NPs are known to interact with plasma proteins, forming a protein corona that can affect particle uptake and toxicity in target cells in a physiological environment. These interactions, leading to the formation of eco-bio-coronas, may be crucial in determining particle behavior and effects also in marine biota. In order to classify NPs into groups and predict the implications of their release into the marine environment, information on

  6. Macroalgal-dominated coastal detritic communities from the Western Mediterranean and the Northeastern Atlantic

    Directory of Open Access Journals (Sweden)

    S. JOHER

    2016-07-01

    Full Text Available This is a qualitative comparison of the distribution of macroalgal-dominated coastal detritic communities from the Western Mediterranean and the Northeastern Atlantic, based on our own data from the Balearic Islands (Western Mediterranean and available data from literature. The macroalgal-dominated coastal detritic bottoms from both regions could be distinguished by the presence of a high number of regional exclusive non-carbonated species, and the presence of a high number of maërl-forming species in the Mediterranean. Further, regional differences in the distribution of some exclusive species allowed the distinction of three zones in the Northeastern Atlantic (United Kingdom, French Brittany and Galicia, while no differences were found within the Western Mediterranean. However, the algal communities considered in the selected literature could not be qualitatively distinguished, and all the samples should be considered as maërl beds. Lithothamnion corallioides and Phymatolithon calcareum were the most widespread maërl forming species in the two regions, while in the Western Mediterranean Spongites fruticulosus was also very frequent. According to the differences in the species composition of the basal and erect strata of these beds, and also in their species richness, five different morphologies of macroalgal-dominated detritic bottoms could be distinguished. Their main characteristic species and their biogeographical distribution are detailed.

  7. Environmental quality of the Fosso della Casaccia. stream (Rome, Italy). Evaluation of the ecological impact of wastewaters from the ENEA Research Centre Casaccia

    International Nuclear Information System (INIS)

    Formichetti, P.; Mancini, L.; Morgana, J.G.; Izzo, G.

    2008-01-01

    The study concerned the evaluation of ENEA Research Centre wastewaters effect on the nearby stream Fosso della Casaccia. These pollutants consist of black waters and low radioactivity substances. The effects on stream's ecosystem were evaluated using macro invertebrate community structure, diatom community structure, chemical and microbiological analysis of sediments and water, stream.s ecological functionality level, toxicological indicators. The results showed a general strong pollution degree of the ecosystem that could also reach a higher level due to the low flow of the stream (and consequent low self-depuration effect of the stream itself). Maintenance interventions, if not adequately planned, can also negatively influence the stream ecosystem [it

  8. Seawater and Detrital Marine Pb Isotopes as Monitors of Antarctic Weathering Following Ice Sheet Development

    Science.gov (United States)

    Fenn, C.; Martin, E. E.; Basak, C.

    2011-12-01

    Comparisons of seawater and detrital Pb isotopes from sites proximal to Antarctica at the Eocene/Oligocene transition (EOT) are being used to understand variations in continental weathering associated with the development of the East Antarctic Ice Sheet (EAIS). Previous work has shown that seawater and detrital archives yield similar isotopic values during Eocene warmth, which is interpreted to record congruent chemical weathering of the continent. In contrast, distinct isotopic values for the two phases at the EOT represents increased incongruent mechanical weathering during growth of the ice sheet. For this study we expanded beyond the initial glaciation at the EOT to determine whether less dramatic changes in ice volume and climate also produce variations in weathering and intensity that are recorded by seawater and detrital Pb isotopes. We collected Nd and Pb isotope data from extractions of Fe-Mn oxide coatings of bulk decarbonated marine sediments, which preserve seawater isotopic values, and from complete dissolutions of the remaining silicate fraction for Ocean Drilling Program Site 748 on Kerguelen Plateau (1300 m modern water depth). The data spans an interval of deglaciation from ~23.5-27 Ma documented by δ18O that has been equated to a ~30% decrease in ice volume on Antarctica (Pekar and Christie-Blick, 2008, Palaeogeogr., Palaeoclim., Palaeoecol.). Initial results from Site 748 include the first ɛNd values for intermediate waters in the Oligocene Southern Ocean and reveal a value of ~-8 over the entire 3.5 my interval, which is consistent with values reported for deep Indian Ocean sites at this time and similar to deeper Southern Ocean sites. Corresponding detrital ɛNd values are less radiogenic and decrease from -9 to -13 during the study interval. Detrital 206Pb/204Pb values also decrease during the warming interval, while seawater 206Pb/204Pb values increase. The decrease in detrital values indicates the composition of source materials entering

  9. Low concentrations of selenium in stream food webs of eastern Canada

    International Nuclear Information System (INIS)

    Jardine, Timothy D.; Kidd, Karen A.

    2011-01-01

    Herbivorous and predatory invertebrates and two species of fish (brook trout and blacknose dace) were collected from 49 streams in New Brunswick, Canada to determine whether concentrations of selenium (Se) in the biota were affected by a point source (a coal-fired power plant), and stream water chemistry (pH, sulphate, conductivity, and total organic carbon), and to determine the trophic transfer of Se through these food webs. Total Se concentrations in the biota were generally low (0.2 to 4.8 μg g -1 dry weight) across sites and there was no relationship between distance from the coal-fired power plant and Se concentrations in invertebrates or fishes. Water chemistry was an equally poor predictor of Se concentrations in invertebrates and fish. Trophic position (determined using δ 15 N) was a significant predictor of Se concentrations in only five of the stream food webs, and two of these had negative slopes, indicating little or no trophic magnification across most systems; many fishes had lower concentrations than their invertebrate prey and trophic transfer was higher at sites with low invertebrate Se concentrations. Variability in Se concentrations in fishes was explained more by site of capture than microhabitat use within the site (as measured with δ 13 C), suggesting among-site differences in geological sources of Se. Because concentrations were below known toxicity thresholds for fish and other consumers, these results suggest that Se is not an environmental issue in New Brunswick streams that do not receive direct inputs from mining activities. - Research Highlights: → Se concentrations in stream invertebrates and fishes in eastern Canada are low. → Concentrations were not related to water chemistry or distance from a point source. → Se did not biomagnify in the food web, yet was almost always in excess of Hg.

  10. Ontogenetic shifts in terrestrial reliance of stream-dwelling brown trout

    Directory of Open Access Journals (Sweden)

    Javier Sánchez-Hernández

    2016-07-01

    Full Text Available This study focuses on terrestrial reliance of brown trout (Salmo trutta and compared it to the potential prey available (macrozoobenthos and drifting invertebrates in three temperate rivers (Galicia, NW Spain, with special emphasis on variations in terrestrial energy intake through the ontogeny of brown trout. Additionally, we paid particular attention to individual variation of terrestrial resource use within and between age classes. Prey items were grouped in four categories: i aquatic invertebrates; ii imagoes of aquatic invertebrates; iii terrestrial invertebrates; and iv fish prey. Next, energy composition was measured according to dry weight-energy equations for each individual in line with above-mentioned prey categories. Our findings illustrate that terrestrial invertebrates appeared to be scarce in the environment, whereas aquatic food resources were rather abundant and accessible. The use of terrestrial invertebrates tended to increase with age, but with a high degree of inter-individual variation in resource use. In fact, the individual reliance of brown trout on terrestrial invertebrates may vary considerably (between 0% and 76.9%. Besides, the frequency of terrestrial foragers, i.e., individuals with terrestrial invertebrates in their stomachs, increased with age, except in one population which had the maximum value in the age-2 class. The acquisition of terrestrial invertebrates thus appears to be a process strongly dependent upon the actual food availability in the environment, but with a high degree of individual variance in resource use within the same age class. Finally, we discuss that terrestrial invertebrates may largely contribute to cover the energy intake of the species, highlighting the interface between terrestrial and aquatic ecosystems, and thereby the importance of riparian canopy cover as a key factor for food supply of stream-dwelling salmonids species.

  11. Investigations into the Settlement and Attachment of Biofouling Marine Invertebrates

    Science.gov (United States)

    2015-12-17

    attachment of biofouling marine invertebrates 5a. CONTRACT NUMBER N00014-12-1 -0432 5b. GRANT NUMBER n/a 5c. PROGRAM ELEMENT NUMBER n/a 6...larval settlement in a variety of marine invertebrate species, including B. neritina. Light also inhibits B. neritina larval settlement, yet the...underlying mechanisms by which light and adrenergic compounds exert their effects on larvae are largely unknown. Octopamine is considered the invertebrate

  12. Contributions of detrital subsidies to aboveground spiders during secondary succession, revealed by radiocarbon and stable isotope signatures.

    Science.gov (United States)

    Haraguchi, Takashi F; Uchida, Masao; Shibata, Yasuyuki; Tayasu, Ichiro

    2013-04-01

    Prey subsidies originating from detritus add nutrients and energy to arboreal communities. Measurement of this subsidy is required in the understanding of how food web dynamics respond to changes in surrounding environments. Shrub spiders are one of the key predators involved in food web coupling. We evaluate the effects of potential changes in prey availabilities during secondary succession on the contribution of subsidy from detrital food webs to shrub spiders and how different spider feeding guilds used the subsidy of prey from detrital food webs. We measured the relative importance of the subsidy for the spider feeding guilds, using the ratios of stable isotopes of C (δ(13)C), and N (δ(15)N) and C isotope discrimination (Δ(14)C). Diet age was calculated from Δ(14)C values, because old diet ages of spiders indicate that the spiders consume prey from detrital food sources. Dominant aerial prey (Diptera) had a distinctively old diet age compared with arboreal prey, which indicates that aerial prey were subsidized from detrital food webs. Sit-and-wait spiders tended to have an older diet age than active hunting spiders, which indicates that sit-and-wait spiders depended more on subsidies. Diet age varied only slightly for spiders in stands of different ages, indicating that rates at which spiders use grazing and detrital prey are probably determined more by foraging strategies and not by stand age. A dominance of sit-and-wait predators will lead to higher detrital subsidy inputs in shrub habitats. This study highlights the effect of shrub spider community structure (feeding guild composition) on the volume of the subsidy received from the detrital food web.

  13. Natural invertebrate hosts of iridoviruses (Iridoviridae)

    Energy Technology Data Exchange (ETDEWEB)

    Williams, Trevor [Instituto de Ecologia A.C., Veracruz (Mexico)]. E-mail: trevor.williams@inecol.edu.mx

    2008-11-15

    Invertebrate iridescent viruses (IIVs) are icosahedral DNA viruses that infect invertebrates, mainly insects and terrestrial isopods, in damp and aquatic habitats. Exhaustive searches of databases resulted in the identification of 79 articles reporting 108 invertebrate species naturally infected by confirmed or putative iridoviruses. Of these, 103 (95%) were arthropods and the remainder were molluscs, an annelid worm and a nematode. Nine species were from marine habitats. Of the 99 non-marine species, 49 were from terrestrial habitats and 50 were aquatic, especially the aquatic stages of Diptera (44 species). The abundance of records from species of Aedes, Ochlerotatus and Psorophora contrasts markedly with a paucity of records from species of Anopheles, Culex and Culiseta. Records from terrestrial isopods are numerous (19 species), although the diversity of IIVs that infect them is mostly unstudied. IIV infections have been reported from every continent, except Antarctica, but there are few records from Africa, southern Asia and Latin America. Most reports describe patent IIV infections as rare whereas inapparent (covert) infection may be common in certain species. The relationship between particle size and iridescent colour of the host is found to be consistent with optical theory in the great majority of cases. Only 24 reported IIVs from insect hosts have partial characterization data and only two have been subjected to complete genome sequencing. I show that the rate of publication on IIVs has slowed from 1990 to the present, and I draw a number of conclusions and suggestions from the host list and make recommendations for future research efforts. (author)

  14. Brain and behavioral lateralization in invertebrates.

    Science.gov (United States)

    Frasnelli, Elisa

    2013-12-11

    Traditionally, only humans were thought to exhibit brain and behavioral asymmetries, but several studies have revealed that most vertebrates are also lateralized. Recently, evidence of left-right asymmetries in invertebrates has begun to emerge, suggesting that lateralization of the nervous system may be a feature of simpler brains as well as more complex ones. Here I present some examples in invertebrates of sensory and motor asymmetries, as well as asymmetries in the nervous system. I illustrate two cases where an asymmetric brain is crucial for the development of some cognitive abilities. The first case is the nematode Caenorhabditis elegans, which has asymmetric odor sensory neurons and taste perception neurons. In this worm left/right asymmetries are responsible for the sensing of a substantial number of salt ions, and lateralized responses to salt allow the worm to discriminate between distinct salt ions. The second case is the fruit fly Drosophila melanogaster, where the presence of asymmetry in a particular structure of the brain is important in the formation or retrieval of long-term memory. Moreover, I distinguish two distinct patterns of lateralization that occur in both vertebrates and invertebrates: individual-level and population-level lateralization. Theoretical models on the evolution of lateralization suggest that the alignment of lateralization at the population level may have evolved as an evolutionary stable strategy in which individually asymmetrical organisms must coordinate their behavior with that of other asymmetrical organisms. This implies that lateralization at the population-level is more likely to have evolved in social rather than in solitary species. I evaluate this new hypothesis with a specific focus on insects showing different level of sociality. In particular, I present a series of studies on antennal asymmetries in honeybees and other related species of bees, showing how insects may be extremely useful to test the evolutionary

  15. Natural invertebrate hosts of iridoviruses (Iridoviridae)

    International Nuclear Information System (INIS)

    Williams, Trevor

    2008-01-01

    Invertebrate iridescent viruses (IIVs) are icosahedral DNA viruses that infect invertebrates, mainly insects and terrestrial isopods, in damp and aquatic habitats. Exhaustive searches of databases resulted in the identification of 79 articles reporting 108 invertebrate species naturally infected by confirmed or putative iridoviruses. Of these, 103 (95%) were arthropods and the remainder were molluscs, an annelid worm and a nematode. Nine species were from marine habitats. Of the 99 non-marine species, 49 were from terrestrial habitats and 50 were aquatic, especially the aquatic stages of Diptera (44 species). The abundance of records from species of Aedes, Ochlerotatus and Psorophora contrasts markedly with a paucity of records from species of Anopheles, Culex and Culiseta. Records from terrestrial isopods are numerous (19 species), although the diversity of IIVs that infect them is mostly unstudied. IIV infections have been reported from every continent, except Antarctica, but there are few records from Africa, southern Asia and Latin America. Most reports describe patent IIV infections as rare whereas inapparent (covert) infection may be common in certain species. The relationship between particle size and iridescent colour of the host is found to be consistent with optical theory in the great majority of cases. Only 24 reported IIVs from insect hosts have partial characterization data and only two have been subjected to complete genome sequencing. I show that the rate of publication on IIVs has slowed from 1990 to the present, and I draw a number of conclusions and suggestions from the host list and make recommendations for future research efforts. (author)

  16. Brain and behavioural lateralization in invertebrates.

    Directory of Open Access Journals (Sweden)

    Elisa eFrasnelli

    2013-12-01

    Full Text Available Traditionally, only humans were thought to exhibit brain and behavioural asymmetries, but several studies have revealed that most vertebrates are also lateralized. Recently, evidence of left-right asymmetries in invertebrates has begun to emerge, suggesting that lateralization of the nervous system may be a feature of simpler brains as well as more complex ones. Here I present some examples in invertebrates of sensory and motor asymmetries, as well as asymmetries in the nervous system. I illustrate two cases where an asymmetric brain is crucial for the development of some cognitive abilities. The first case is the nematode C. elegans, which has asymmetric odour sensory neurons and taste perception neurons. In this worm left/right asymmetries are responsible for the sensing of a substantial number of salt ions, and lateralized responses to salt allow the worm to discriminate between distinct salt ions. The second case is the fruit fly D. melanogaster, where the presence of asymmetry in a particular structure of the brain is important in the formation or retrieval of long-term memory. Moreover, I distinguish two distinct patterns of lateralization that occur in both vertebrates and invertebrates: individual-level and population-level lateralization. Theoretical models on the evolution of lateralization suggest that the alignment of lateralization at the population level may have evolved as an evolutionary stable strategy in which individually-asymmetrical organisms must coordinate their behaviour with that of other asymmetrical organisms. This implies that lateralization at the population-level is more likely to have evolved in social rather than in solitary species. I evaluate this new hypothesis with specific focus on insects showing different level of sociality. In particular, I present a series of studies on antennal asymmetries in honeybees and other related species of bees, showing how insects may be extremely useful to test evolutionary

  17. The Global Invertebrate Genomics Alliance (GIGA): Developing Community Resources to Study Diverse Invertebrate Genomes

    KAUST Repository

    Bracken-Grissom, Heather

    2013-12-12

    Over 95% of all metazoan (animal) species comprise the invertebrates, but very few genomes from these organisms have been sequenced. We have, therefore, formed a Global Invertebrate Genomics Alliance (GIGA). Our intent is to build a collaborative network of diverse scientists to tackle major challenges (e.g., species selection, sample collection and storage, sequence assembly, annotation, analytical tools) associated with genome/transcriptome sequencing across a large taxonomic spectrum. We aim to promote standards that will facilitate comparative approaches to invertebrate genomics and collaborations across the international scientific community. Candidate study taxa include species from Porifera, Ctenophora, Cnidaria, Placozoa, Mollusca, Arthropoda, Echinodermata, Annelida, Bryozoa, and Platyhelminthes, among others. GIGA will target 7000 noninsect/nonnematode species, with an emphasis on marine taxa because of the unrivaled phyletic diversity in the oceans. Priorities for selecting invertebrates for sequencing will include, but are not restricted to, their phylogenetic placement; relevance to organismal, ecological, and conservation research; and their importance to fisheries and human health. We highlight benefits of sequencing both whole genomes (DNA) and transcriptomes and also suggest policies for genomic-level data access and sharing based on transparency and inclusiveness. The GIGA Web site () has been launched to facilitate this collaborative venture.

  18. Soil invertebrate communities in stressed European ecosystems

    Energy Technology Data Exchange (ETDEWEB)

    Butovsky, R.O. [All-Russian Research Institute for Nature Protection, Sadki-Znamenskoje (Russian Federation)

    2003-07-01

    Intensive landuse in Europe results in continual physical and chemical changes to land and soil. Soil invertebrates can be used for development of single- and multi-species test-systems for soil quality assessment under anthropogenous stress. The research was performed in 18 terrestrial ecosystems stressed by common anthropogenous impacts: recreation pressure, motorway or industrial pollution in Central Russia, Belgium and the Netherlands in 1983-2001. All three types of human stresses (recreation, motorway and industrial) induced similar changes of macroartropod and microarthropod communities. In stressed macroarthropod communities the decrease of abundance of non-specialized predators, chewing phytophagans, saprophagans and increase of abundance of rhyzophagans, sucking phytophagans and specialized predators was observed. All types of stresses increased or stabilized species diversity in macro- (in carabid beetles communities mainly increase of Harpalus and Amara species number, in weevils - Sitona species number etc.) and microarthropod (e.g. Mesostigmata mites species) communities. In stressed ecosystems sucking phytophagans have selective advantage as compared to chewing phytophagans, endoparasitoids as compared to ectoparasitoids, specialized predators as compared to non-specialized predators etc., meaning that the feeding strategy play an important regulatory role in the community. Saprophagans and phytophagans, consuming chemicals, e.g. heavy metals in large quantities, are in general highly sensitive groups. The most sensitive groups belonged to first and second order consumers. In putative trophic chains in roadside ecosystems, non-specialized zoophagans (predators) contained less copper and zinc, than specialized zoophagans and parasitoids. When compared to the peculiarities of distribution of pesticides (e.g. DDT) and radionuclides (Sr90 and Cs137) it happens that in terrestrial ecosystems heavy metals were primarily accumulated (1) in soil

  19. Developmental biology in marine invertebrate symbioses.

    Science.gov (United States)

    McFall-Ngai, M J; Ruby, E G

    2000-12-01

    Associations between marine invertebrates and their cooperative bacterial symbionts offer access to an understanding of the roots of host-microbe interaction; for example, several symbioses like the squid-vibrio light organ association serve as models for investigating how each partner affects the developmental biology of the other. Previous results have identified a program of specific developmental events that unfolds as the association is initiated. In the past year, published studies have focused primarily on describing the mechanisms underlying the signaling processes that occur between the juvenile squid and the luminous bacteria that colonize it.

  20. Detrital rutile geochemistry and thermometry from the Dabie orogen: Implications for source-sediment links in a UHPM terrane

    Science.gov (United States)

    Liu, Lei; Xiao, Yilin; Wörner, G.; Kronz, A.; Simon, K.; Hou, Zhenhui

    2014-08-01

    This study explores the potential of detrital rutile geochemistry and thermometry as a provenance tracer in rocks from the Central Dabie ultrahigh-pressure metamorphic (UHPM) zone in east-central China that formed during Triassic continental collision. Trace element data of 176 detrital rutile grains selected from local river sediments and 91 rutile grains from distinct bedrocks in the Shuanghe and Bixiling areas, obtained by both electron microprobe (EMP) and in situ LA-ICP-MS analyses, suggest that geochemical compositions and thermometry of detrital rutiles are comparable to those from their potential source rocks. After certification of the Cr-Nb discrimination method for the Central Dabie UHPM zone, we show that 29% of the detrital rutiles in the Shuanghe area were derived from metamafic sources whereas in the Bixiling area that it is up to 76%. Furthermore, the proportion of distinct types of detrital rutiles combined with modal abundances of rutile in metapelites and metamafic bedrocks can be used to estimate the proportion of different source lithologies. Based on this method the proportion of mafic source rocks was estimated to ∼10% at Shuanghe and >60% at Bixiling, respectively, which is consistent with the proportions of eclogite (the major rutile-bearing metamafic rock) distribution in the field. Therefore, the investigation of detrital rutiles is a potential way to evaluate the proportion of metamafic rocks and even to prospect for metamafic bodies in UHPM terranes. Zr-in-rutile temperatures were calculated at different pressures and compared with temperatures derived from rock-in rutiles and garnet-clinopyroxene Fe-Mg thermometers. Temperatures calculated for detrital rutiles range from 606 °C to 707 °C and 566 °C to 752 °C in Shuanghe and Bixiling, respectively, at P = 3 GPa with an average temperatures of ca. 630 °C for both areas. These temperature averages and ranges are similar to those calculated for rutiles from surrounding source rocks

  1. Longitudinal and seasonal changes in functional organization of macroinvertebrate communities in four Oregon streams.

    OpenAIRE

    Hawkins, C. P.; Sedell, J. R.

    1981-01-01

    Relative numerical dominance and densities of invertebrate functional feeding groups are compared with longitudinal and seasonal changes in food resources in a Cascade Range stream system in Oregon. We also compare our data with hypothetical predictions of the River Continuum model. We found that both relative abundances and densities of functional groups fit qualitative characterization of stream reaches and the River Continuum model: Shredders dominated upper shaded reaches; scrapers were m...

  2. Relapse to cocaine seeking in an invertebrate.

    Science.gov (United States)

    Amaning-Kwarteng, Akua O; Asif-Malik, Aman; Pei, Yue; Canales, Juan J

    2017-06-01

    Addiction is characterised by cycles of compulsive drug taking, periods of abstinence and episodes of relapse. The extinction/reinstatement paradigm has been extensively used in rodents to model human relapse and explore underlying mechanisms and therapeutics. However, relapse to drug seeking behaviour has not been previously demonstrated in invertebrates. Here, we used a cocaine conditioned place preference (CPP) paradigm in the flatworm, planarian, followed by extinction and reinstatement of drug seeking. Once baseline preference was established for one of two distinctly textured environments (i.e. compartments with a coarse or smooth surface), planarian received pairings of cocaine (5μM) in the non-preferred, and vehicle in the most preferred, environment, and were tested for conditioning thereafter. Cocaine produced robust CPP, measured as a significant increase in the time spent in the cocaine-paired compartment. Subsequently, planarian underwent extinction training, reverting back to their original preference within three sessions. Brief exposure to cocaine (5μM) or methamphetamine (5μM) reinstated cocaine-seeking behaviour. By contrast, the high affinity dopamine transporter inhibitor, (N-(n-butyl)-3α-[bis (4-fluorophenyl) methoxy]-tropane) (JHW007), which in rodents exhibits a neurochemical and behavioural profile distinct from cocaine, was ineffective. The present findings demonstrate for the first time reinstatement of extinguished cocaine seeking in an invertebrate model and suggest that the long-term adaptations underlying drug conditioning and relapse are highly conserved through evolution. Copyright © 2017 Elsevier Inc. All rights reserved.

  3. The development of a system to assess the ecological quality of streams based on macroinvertebrates - design of the sampling programme within the AQEM project

    NARCIS (Netherlands)

    Hering, D.; Buffagni, A.; Moog, O.; Sandin, L.; Sommerhäuser, M.; Strubauer, I.; Feld, C.; Johnson, R.; Pinto, P.; Skoulikidis, N.; Verdonschot, P.F.M.; Zahrádková, S.

    2003-01-01

    The EU Water Framework Directive (WFD) requires river assessment systems based on benthic invertebrates. The AQEM project is developing, at a European scale, such a methodology, based on a comparison of communities of reference streams and degraded streams. The project is focussing on three main

  4. Ecological consequences of antibiotic exposure to periphyton in naturally colonizing stream mesocosms

    Science.gov (United States)

    Tetracycline and its derivatives are extensively used human and animal antibiotics, and enter stream ecosystems via point and non-point sources. Laboratory studies indicate that microbial organisms are more sensitive to antibiotics than invertebrates or fish, and may indicate t...

  5. Responses of primary production, leaf litter decomposition and associated communities to stream eutrophication

    International Nuclear Information System (INIS)

    Dunck, Bárbara; Lima-Fernandes, Eva; Cássio, Fernanda; Cunha, Ana; Rodrigues, Liliana; Pascoal, Cláudia

    2015-01-01

    We assessed the eutrophication effects on leaf litter decomposition and primary production, and on periphytic algae, fungi and invertebrates. According to the subsidy-stress model, we expected that when algae and decomposers were nutrient limited, their activity and diversity would increase at moderate levels of nutrient enrichment, but decrease at high levels of nutrients, because eutrophication would lead to the presence of other stressors and overwhelm the subsidy effect. Chestnut leaves (Castanea sativa Mill) were enclosed in mesh bags and immersed in five streams of the Ave River basin (northwest Portugal) to assess leaf decomposition and colonization by invertebrates and fungi. In parallel, polyethylene slides were attached to the mesh bags to allow colonization by algae and to assess primary production. Communities of periphytic algae and decomposers discriminated the streams according to the trophic state. Primary production decomposition and biodiversity were lower in streams at both ends of the trophic gradient. - Highlights: • Algae and decomposers discriminated the streams according to the eutrophication level. • Primary production and litter decomposition are stimulated by moderate eutrophication. • Biodiversity and process rates were reduced in highly eutrophic streams. • Subsidy-stress model explained biodiversity and process rates under eutrophication. - Rates of leaf litter decomposition, primary production and richness of periphytic algae, fungi and invertebrates were lower in streams at both ends of the trophic gradient

  6. Management in a neotropical show cave: planning for invertebrates conservation

    Directory of Open Access Journals (Sweden)

    Thais Giovannini Pellegrini

    2012-07-01

    Full Text Available Lapa Nova is a dolomitic cave about 4.5 km long located in northwestern Minas Gerais state, Brazil. The cave experiences intense tourism, concentrated over a single period of the year, during the Feast of Our Lady of Lapa. In order to evaluate the impacts felt by the invertebrate community from this tourism, a new methodology was proposed. Four types of areas (intense visitation area, outlying visitation areas, moderate visitation areas and no-visitation areas were sampled for invertebrates. There was one sampling prior and another on the last day of the 128th feast, to evaluate the effects of visitation on cave-dwelling invertebrates. Results show that invertebrate populations residing in more intensely visited areas of the cave undergo changes in distribution following the event. As a consequence of tourism, invertebrates shift to outlying locations from the visited area, which serve as refuges to the communities. Apparently, the fact that there are places inside Lapa Nova inaccessible to tourists reduces the impact suffered by the invertebrate community, as those sites serve as refuges for cave-dwelling organisms during the pilgrimage. A proper management plan was devised for the tourism/religious use of the cave. It consists basically of delimiting marked pathways for tourists, allowing invertebrates to seek shelter at locations outside visited areas and keeping no-visitation areas off-limits to tourism based on the results of the visitation effects on cave-dwelling invertebrates.

  7. 50 CFR 17.85 - Special rules-invertebrates.

    Science.gov (United States)

    2010-10-01

    ... 50 Wildlife and Fisheries 2 2010-10-01 2010-10-01 false Special rules-invertebrates. 17.85 Section 17.85 Wildlife and Fisheries UNITED STATES FISH AND WILDLIFE SERVICE, DEPARTMENT OF THE INTERIOR....85 Special rules—invertebrates. (a) Seventeen mollusks in the Tennessee River. The species in the...

  8. Invertebrates of the Columbia River basin assessment area.

    Science.gov (United States)

    Christine G. Niwa; Roger E. Sandquist; Rod Crawford; et al.

    2001-01-01

    A general background on functional groups of invertebrates in the Columbia River basin and how they affect sustainability and productivity of their ecological communities is presented. The functional groups include detritivores, predators, pollinators, and grassland and forest herbivores. Invertebrate biodiversity and species of conservation interest are discussed....

  9. Reduced detrital resources limit Pycnopsyche gentilis (Trichoptera: Limnephilidae) production and growth

    Science.gov (United States)

    Susan L. Eggert; J. Bruce Wallace

    2003-01-01

    Leaf inputs in temperate forest streams may limit caddisfly production because leaf detritus serves both as a food and case-material resource. We estimated Pycnopsyche gentilis produdion in a stream experimentally decoupled fmm its riparian habitat and a reference stream for 8 y in the southern Appalachians. We also examined laboratory survivorship,...

  10. Functional and phylogenetic relatedness in temporary wetland invertebrates: current macroecological patterns and implications for future climatic change scenarios.

    Science.gov (United States)

    Ruhí, Albert; Boix, Dani; Gascón, Stéphanie; Sala, Jordi; Batzer, Darold P

    2013-01-01

    In freshwater ecosystems, species compositions are known to be determined hierarchically by large to small‑scale environmental factors, based on the biological traits of the organisms. However, in ephemeral habitats this heuristic framework remains largely untested. Although temporary wetland faunas are constrained by a local filter (i.e., desiccation), we propose its magnitude may still depend on large-scale climate characteristics. If this is true, climate should be related to the degree of functional and taxonomic relatedness of invertebrate communities inhabiting seasonal wetlands. We tested this hypothesis in two ways. First, based on 52 biological traits for invertebrates, we conducted a case study to explore functional trends among temperate seasonal wetlands differing in the harshness (i.e., dryness) of their dry season. After finding evidence of trait filtering, we addressed whether it could be generalized across a broader climatic scale. To this end, a meta-analysis (225 seasonal wetlands spread across broad climatic categories: Arid, Temperate, and Cold) allowed us to identify whether an equivalent climate-dependent pattern of trait richness was consistent between the Nearctic and the Western Palearctic. Functional overlap of invertebrates increased from mild (i.e., Temperate) to harsher climates (i.e., Arid and Cold), and phylogenetic clustering (using taxonomy as a surrogate) was highest in Arid and lowest in Temperate wetlands. We show that, (i) as has been described in streams, higher relatedness than would be expected by chance is generally observed in seasonal wetland invertebrate communities; and (ii) this relatedness is not constant but climate-dependent, with the climate under which a given seasonal wetland is located determining the functional overlap and the phylogenetic clustering of the community. Finally, using a space-for-time substitution approach we suggest our results may anticipate how the invertebrate biodiversity embedded in these

  11. Settling distances of benthic invertebrates in a sediment mobilization simulation in semi-natural flumes

    Directory of Open Access Journals (Sweden)

    Maria Cristina Bruno

    2015-10-01

    Full Text Available Drift time and distance depend on the ability of the drifting invertebrates to alter their body posture or by swimming, and these behaviors may change according to the local hydraulic environment, resulting in different distances travelled before exiting the drift. Such drift and settlement mediated invertebrate movement determine dispersal processes and ultimately generates distribution patterns within streams. We conducted an experiment in an open-air, artificial flume system directly fed by an Alpine stream, where we disturbed the sediment in the flumes, inducing catastrophic drift in the benthic community, and then assessed the settlement distances of benthic invertebrates. For each flume, we collected drift samples by disturbing the substrate at 1.5 m intervals, at increasing distance from the downstream end, for a total of 7 disturbances and a maximum settling distance of 10 m in each flume, with five replicates (i.e., five flumes for each disturbance. The disturbances induced a massive catastrophic drift in Ephemeroptera, Plecoptera and Trichoptera, always higher than the behaviorally-occurring basedrift. The Settling Index calculated over the total drift collected at each distance increased with increasing distance, and after 10 m, 90% of the drifting animals had settled. Evenness and taxa richness progressively decrease with increasing settling distance. All drifting taxa were represented mainly by young instars. We used the drift collected at 1 m from the disturbance to standardize the remaining samples, based on the assumption that 1 m is not a distance long enough to allow animals to settle at that water velocity. We calculated the percentage of possible drifters which settled by computing a Settling Index for each taxon. The drifting taxa listed by decreasing Settling Index scores were Epeorus sp., Rhithrogena semicolorata, Isoperla spp., Sericostoma spp., Ecdyonurus spp., Nemoura spp., Leuctra spp., Baetis spp., Hydropsyche spp

  12. Soil invertebrates as bioindicators of urban soil quality

    International Nuclear Information System (INIS)

    Santorufo, Lucia; Van Gestel, Cornelis A.M.; Rocco, Annamaria; Maisto, Giulia

    2012-01-01

    This study aimed at relating the abundance and diversity of invertebrate communities of urban soils to chemical and physical soil characteristics and to identify the taxa most sensitive or tolerant to soil stressors. The invertebrate community of five urban soils in Naples, Italy, was sampled. To assess soil quality invertebrate community indices (Shannon, Simpson, Menhinick and Pielou indices), Acarina/Collembola ratios, and the soil biological quality index (QBS) were calculated. The chemical and physical characteristics of the soils strongly differed. Abundance rather than taxa richness of invertebrates were more affected by soil characteristics. The community was more abundant and diverse in the soils with high organic matter and water content and low metal (Cu, Pb, Zn) concentrations. The taxa more resistant to the urban environment included Acarina, Enchytraeids, Collembola and Nematoda. Collembolans appeared particularly sensitive to changing soil properties. Among the investigated indices, QBS seems most appropriate for soil quality assessment. - Highlights: ► The abundance and diversity of invertebrate communities was related to properties and metal contents of urban soils. ► Several (biodiversity) indices were calculated and compared to evaluate soil quality. ► Metal contamination affected invertebrate density and diversity. ► The taxa more tolerant to metal contamination were Acarina, Enchytraeids, Collembola and Nematoda. ► The soil biological quality index QBS index was most appropriate for soil quality assessment. - Soil metal contamination negatively affected soil invertebrate abundance and diversity.

  13. Trophic pathways supporting Arctic grayling in a small stream on the Arctic Coastal Plain, Alaska

    Science.gov (United States)

    McFarland, Jason J.; Wipfli, Mark S.; Whitman, Matthew S.

    2018-01-01

    Beaded streams are prominent across the Arctic Coastal Plain (ACP) of Alaska, yet prey flow and food web dynamics supporting fish inhabiting these streams are poorly understood. Arctic grayling (Thymallus arcticus) are a widely distributed upper-level consumer on the ACP and migrate into beaded streams to forage during the short 3-month open-water season. We investigated energy pathways and key prey resources that support grayling in a representative beaded stream, Crea Creek. We measured terrestrial invertebrates entering the stream from predominant riparian vegetation types, prey types supporting a range of fish size classes, and how riparian plants and fish size influenced foraging habits. We found that riparian plants influenced the quantity of terrestrial invertebrates entering Crea Creek; however, these differences were not reflected in fish diets. Prey type and size ingested varied with grayling size and season. Small grayling (15 cm FL) foraged most heavily on ninespine stickleback (Pungitius pungitius) throughout the summer, indicating that grayling can be insectivorous and piscivorous, depending on size. These findings underscore the potential importance of small streams in Arctic ecosystems as key summer foraging habitats for fish. Understanding trophic pathways supporting stream fishes in these systems will help interpret whether and how petroleum development and climate change may affect energy flow and stream productivity, terrestrial–aquatic linkages and fishes in Arctic ecosystems.

  14. 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.

  15. Relation of periphyton and benthic invertebrate communities to environmental factors and land use at selected sites in part of the upper Mississippi River basin, 1996-98

    Science.gov (United States)

    ZumBerge, Jeremy Ryan; Lee, Kathy E.; Goldstein, Robert M.

    2003-01-01

    The Upper Mississippi River Basin is one of the hydrologic systems selected for study by the National Water-Quality Assessment (NAWQA) Program of the U.S. Geological Survey. NAWQA utilizes a multi-disciplinary approach to explain factors that affect water quality. Part of the NAWQA design addresses the relation of land use and environmental factors to periphyton and benthic invertebrate communities in streams.

  16. U-Pb ages of detrital zircon from Pegasus Group, Stewart Island

    International Nuclear Information System (INIS)

    Walker, N.; Tulloch, A.J.; Allibone, A.

    1998-01-01

    Stewart Island (New Zealand) is relatively unaffected by Cenozoic deformation related to the present-day plate boundary and has thus been a locale of investigations that focus on the relationship between Mesozoic continental margin magmatic rocks and the Western Province (WP) of NZ. Pegasus Group metasedimentary rocks represent the only candidate for WP equivalents on Stewart Island. We measured U-Pb and 207 Pb / 206 Pb ages of detrital zircons from the Pegasus Group in an effort to validate the correlation with the WP. On SI, Pegasus Group is exposed over a small area in the southern Tin Range where it forms amphibolite facies roof pendants and screens among plutons of mid Paleozoic to mid Cretaceous age. Mica schists predominate, with lesser amounts of psammite and metaquartzite and rare calcareous schist and amphibolite. Zircons were extracted from metaquarzite and 24 grains were chosen on the basis of morphology for geochronologic investigation. Sixteen single crystals were dated by U-Pb TIMS; 8 additional grains were studied by the total evaporation method described by Kober. Despite vigorous air abrasion prior to processing, the 16 grains measured by conventional U-Pb TIMS yielded slightly normally discordant ages that we interpret to reflect minor Pb-loss. The 8 grains studied by the total evaporation method yielded more than four analytically identical /sup 207 Pb / 206 Pb ages within each grain at progressively higher temperatures (1515-1580 degrees C) of evaporation. The results permit the following general conclusions: 1) the age range of 420-2700 Ma is grossly similar to that reported from the Greenland Group/Victoria Paragneiss (Ireland 1992) of the Buller Terrane, WP; 2) the zircon population is dominantly 530-680 Ma but a subsidiary population is 900-1100 Ma; 3) no zircons with ages that match the timing of the Ross Orogen (530-480 Ma) were identified; 4) two grains of 420 Ma and a 453 Ma are probably too young for the paleontogically

  17. Provenance of the lower Miocene of the Gulf of Mexico from detrital zircon double dating

    Science.gov (United States)

    xu, J.

    2013-12-01

    The lower Miocene interval of the Gulf of Mexico (GOM) has recently gained increasing attention from oil and gas industry due to its hydrocarbon potential below the salt canopy. However, it has been less well studied than both the underlying Oligocene and overlying middle Miocene strata. The lower Miocene worldwide is a transitional period of tectonic, climatic, and oceanographic change. In particular, it is a period of major tectonic reorganization in the western interior of North America (Rocky Mountains), involving a shift from the Oligocene thermal phase, with abundant volcanic activity recorded in the thick Frio/Vicksburg succession of the GOM, to the Miocene Basin-Range extensional phase. Climatic conditions also changed from a relatively arid Oligocene to wetter Miocene, resulting in increased sediment yields from exhumed tectonic structures. Previous provenance studies used proportions of quartz, feldspar and lithic fragments and consideration of likely river courses through known paleogeomorphological elements. Only limited detrital zircon (DZ) U-Pb studies on Paleocene strata have been undertaken and there has been no previous U-Pb and (U-Th)/He double dating in the GOM. In this study we apply the latest analytical approaches, such as DZ U-Pb dating to gain robust source terranes ages and more fully elucidate the complex sediment provenance and dispersal history of GOM. We also employ DZ (U-Th)/He (ZHe) dating, combined with DZ U-Pb, to not only define sedimentary provenance but also the exhumation histories of detrital source regions. Samples of lower Miocene outcrop exposures in Texas and Louisiana have been collected to discriminate the varied tectonic and drainage system changes across the basin in lateral. In addition, samples from the Eocene, Oligocene and middle Miocene have been obtained to reveal vertical shift of source terranes contributions. Our initial age data show detrital zircons of lower Miocene sediments come from a wide range of source

  18. Antimicrobial Compounds from Marine Invertebrates-Derived Microorganisms.

    Science.gov (United States)

    Liu, Juan; Jung, Jee H; Liu, Yonghong

    2016-01-01

    It is known that marine invertebrates, including sponges, tunicates, cnidaria or mollusks, host affluent and various communities of symbiotic microorganisms. The microorganisms associated with the invertebrates metabolized various biologically active compounds, which could be an important resource for the discovery and development of potentially novel drugs. In this review, the new compounds with antimicrobial activity isolated from marine invertebrate-derived microorganisms in the last decade (2004-2014) will be presented, with focus on the relevant antimicrobial activities, origin of isolation, and information of strain species. New compounds without antimicrobial activity were not revealed.

  19. RNA interference-mediated intrinsic antiviral immunity in invertebrates.

    Science.gov (United States)

    Nayak, Arabinda; Tassetto, Michel; Kunitomi, Mark; Andino, Raul

    2013-01-01

    In invertebrates such as insects and nematodes, RNA interference (RNAi) provides RNA-based protection against viruses. This form of immunity restricts viral replication and dissemination from infected cells and viruses, in turn, have evolved evasion mechanisms or RNAi suppressors to counteract host defenses. Recent advances indicate that, in addition to RNAi, other related small RNA pathways contribute to antiviral functions in invertebrates. This has led to a deeper understanding of fundamental aspects of small RNA-based antiviral immunity in invertebrates and its contribution to viral spread and pathogenesis.

  20. Response of invertebrates from the hyporheic zone of chalk rivers to eutrophication and land use.

    Science.gov (United States)

    Pacioglu, Octavian; Moldovan, Oana Teodora

    2016-03-01

    Whereas the response of lotic benthic macroinvertebrates to different environmental stressors is a widespread practice nowadays in assessing the water and habitat quality, the use of hyporheic zone invertebrates is still in its infancy. In this study, classification and regression trees analysis were employed in order to assess the ecological requirements and the potential as bioindicators for the hyporheic zone invertebrates inhabiting four lowland chalk rivers (south England) with contrasting eutrophication levels (based on surface nitrate concentrations) and magnitude of land use (based on percentage of fine sediments load and median interstitial space). Samples of fauna, water and sediment were sampled twice, during low (summer) and high (winter) groundwater level, at depths of 20 and 35 cm. Certain groups of invertebrates (Glossosomatidae and Psychomyiidae caddisflies, and riffle beetles) proved to be good indicators of rural catchments, moderately eutrophic and with high fine sediment load. A diverse community dominated by microcrustaceans (copepods and ostracods) were found as good indicators of highly eutrophic urban streams, with moderate-high fine sediment load. However, the use of other taxonomic groups (e.g. chironomids, oligochaetes, nematodes, water mites and the amphipod Gammarus pulex), very widespread in the hyporheic zone of all sampled rivers, is of limited use because of their high tolerance to the analysed stressors. We recommend the use of certain taxonomic groups (comprising both meiofauna and macroinvertebrates) dwelling in the chalk hyporheic zone as indicators of eutrophication and colmation and, along with routine benthic sampling protocols, for a more comprehensive water and habitat quality assessment of chalk rivers.

  1. Invertebrate-Based Water Quality Impairments and Associated Stressors Identified through the US Clean Water Act

    Science.gov (United States)

    Govenor, Heather; Krometis, Leigh Anne H.; Hession, W. Cully

    2017-10-01

    Macroinvertebrate community assessment is used in most US states to evaluate stream health under the Clean Water Act. While water quality assessment and impairment determinations are reported to the US Environmental Protection Agency, there is no national summary of biological assessment findings. The objective of this work was to determine the national extent of invertebrate-based impairments and to identify pollutants primarily responsible for those impairments. Evaluation of state data in the US Environmental Protection Agency's Assessment and Total Maximum Daily Load Tracking and Implementation System database revealed considerable differences in reporting approaches and terminologies including differences in if and how states report specific biological assessment findings. Only 15% of waters impaired for aquatic life could be identified as having impairments determined by biological assessments (e.g., invertebrates, fish, periphyton); approximately one-third of these were associated with macroinvertebrate bioassessment. Nearly 650 invertebrate-impaired waters were identified nationwide, and sediment was the most common pollutant in bedded (63%) and suspended (9%) forms. This finding is not unexpected, given previous work on the negative impacts of sediment on aquatic life, and highlights the need to more specifically identify the mechanisms driving sediment impairments in order to design effective remediation plans. It also reinforces the importance of efforts to derive sediment-specific biological indices and numerical sediment quality guidelines. Standardization of state reporting approaches and terminology would significantly increase the potential application of water quality assessment data, reveal national trends, and encourage sharing of best practices to facilitate the attainment of water quality goals.

  2. Spatial distribution of detrital resources determines the outcome of competition between bacteria and a facultative detritivorous worm

    NARCIS (Netherlands)

    Van Nugteren, P.; Herman, P.M.J.; Moodley, L.; Middelburg, J.J.; Vos, M.; Heip, C.H.R.

    2009-01-01

    Macrobenthic deposit feeders and bacteria compete for the same detrital food resources. We hypothesize that the spatial scale at which food is distributed in the sediment is an important factor determining the outcome of this competition. Macrobenthic deposit feeders are better adapted for fast

  3. Bacterial traits, organism mass, and numerical abundance in the detrital soil food web of Dutch agricultural grasslands

    NARCIS (Netherlands)

    Mulder, C.; Cohen, J.E.; Setälä, H.; Bloem, J.; Breure, A.M.

    2005-01-01

    This paper compares responses to environmental stress of the ecophysiological traits of organisms in the detrital soil food webs of grasslands in the Netherlands, using the relationship between average body mass M and numerical abundance N. The microbial biomass and biodiversity of belowground fauna

  4. Detrital and early chemical remanent magnetization in redbeds and their rock magnetic signature: Zicapa Formation, southern Mexico

    Science.gov (United States)

    Sierra-Rojas, Maria Isabel; Molina-Garza, Roberto Stanley

    2018-06-01

    Poles from continental redbeds are a large fraction of the world's palaeomagnetic database. Nonetheless, the time of acquisition and origin of the remanent magnetization of redbeds has been long debated. We report palaeomagnetic data, rock magnetic data and microscope observations for Lower Cretaceous redbeds in southern Mexico. These data allow us to discriminate between the hysteresis properties of remanent magnetizations of detrital and chemical origin, and to establish the early origin of a chemical remanence. Red sandstones of the Zicapa Formation contain a multicomponent remanence revealed by thermal demagnetization, and consisting of three stable components with partially overlapping laboratory unblocking temperatures of 600 °C, (low, intermediate and high temperature, respectively). They are interpreted as a viscous remanence residing in detrital magnetite, a chemical remanence residing in authigenic hematite and a depositional remanence residing in detrital hematite, respectively. The low-temperature component is nearly parallel to the recent dipole field. The tilt-corrected overall site means of the intermediate (chemical) and high temperature (depositional) components are indistinguishable (Dec = 282.0°, Inc = 12.4°, k = 13.33, α95 = 10.1°, N = 17, for the intermediate temperature; and Dec = 272.5°, Inc = 16.5°, k = 14.04, α95 = 11, N = 14, for the high temperature). Elongation/inclination analysis suggests that depositional and chemical components require applying an f = factor of approximately 0.4. Both of these components define a magnetic polarity zonation, but the polarity of the chemical and detrital components may or may not be the same. The chemical remanence coincides, more often than not, with the polarity of the depositional remanence of the overlying (younger) strata, suggesting a delay in remanence acquisition of tens to a few hundred ka for the chemical component. Pigmentary and detrital haematite were recognized with microscopic

  5. Field and laboratory investigations on the effects of road salt (NaCl) on stream macroinvertebrate communities

    International Nuclear Information System (INIS)

    Blasius, B.J.; Merritt, R.W.

    2002-01-01

    Short-term exposure to road salt did not significantly affect stream macro-invertebrate communities. - Field and laboratory experiments were conducted to examine the effects of road salt (NaCl) on stream macroinvertebrates. Field studies investigated leaf litter processing rates and functional feeding group composition at locations upstream and downstream from point source salt inputs in two Michigan, USA streams. Laboratory studies determined the effects of increasing NaCl concentrations on aquatic invertebrate drift, behavior, and survival. Field studies revealed that leaves were processed faster at upstream reference sites than at locations downstream from road salt point source inputs. However, it was sediment loading that resulted in partial or complete burial of leaf packs, that affected invertebrate activity and confounded normal leaf pack colonization. There were no significant differences that could be attributed to road salt between upstream and downstream locations in the diversity and composition of invertebrate functional feeding groups. Laboratory drift and acute exposure studies demonstrated that drift of Gammarus (Amphipoda) may be affected by NaCl at concentrations greater than 5000 mg/l for a 24-h period. This amphipod and two species of limnephilid caddisflies exhibited a dose response to salt treatments with 96-h LC 50 values of 7700 and 3526 mg NaCl/l, respectively. Most other invertebrate species and individuals were unaffected by NaCl concentrations up to 10,000 mg/l for 24 and 96 h, respectively

  6. Water Temperature, Invertebrate Drift, and the Scope for Growth for Juvenile Spring Chinook Salmon.

    Science.gov (United States)

    Lovtang, J. C.; Li, H. W.

    2005-05-01

    We present a bioenergetic assessment of habitat quality based on the concept of the scope for growth for juvenile Chinook salmon. Growth of juvenile salmonids during the freshwater phase of their life history depends on a balance between two main factors: energy intake and metabolic costs. The metabolic demands of temperature and the availability of food play integral roles in determining the scope for growth of juvenile salmonids in stream systems. We investigated differences in size of juvenile spring Chinook salmon in relation to water temperature and invertebrate drift density in six unique study reaches in the Metolius River Basin, a tributary of the Deschutes River in Central Oregon. This project was initiated to determine the relative quality and potential productivity of habitat in the Metolius Basin prior to the reintroduction of spring Chinook salmon, which were extirpated from the middle Deschutes basin in the early 1970's due to the construction of a hydroelectric dam. Variations in the growth of juvenile Chinook salmon can be described using a multiple regression model of water temperature and invertebrate drift density. We also discuss the relationships between our bioenergetic model, variations of the ideal free distribution model, and physiological growth models.

  7. Radiocesium in aquatic invertebrates from Dovrefjell, Norway, 1986 to 1989, after the Chernobyl fall-out

    International Nuclear Information System (INIS)

    Solem, J.O.

    1992-01-01

    Following the fall-out in 1986 from Chernobyl, the activity of 137 Cs was measured in invertebrates sampled in streams and temporary pools at 930 m above sea level at Dovrefjell, Norway. Species with different feeding habits were selected, predators (e.g. Trichoptera, gen. Rhyacophila), shredders (e.g. Trichoptera, gen. Halesus), collectors/filterers (e.g. Trichoptera, gen. Polycentropus) and plankton feeders (e.g. Cladocera, gen. Daphnia and Anostraca, gen. Branchinecta). Samples were preserved in 96% ethanol and were weighed to be between 0.05 and 2g. A sample thus consisted of many individuals. The 1986 radiocesium values vary considerably between and within species, and may reflect a patchy fall-out. The 1987, 1988 and 1989 data are much more consistent and are significantly lower than the 1986 values. The invertebrate predators have low radiocesium values and these showed a rapid decrease, whereas species eating dead or living plant material have measurable amounts of radiocesium in all the years. The data from 1987 and 1988 are fairly similar, but the 1989 data deviate from the previous two years. This difference may be caused by changes in deposition or transport of radiocesium in plants and soil. (author)

  8. Evaluating effects of potential changes in streamflow regime on fish and aquatic-invertebrate assemblages in the New Jersey Pinelands

    Science.gov (United States)

    Kennen, Jonathan G.; Riskin, Melissa L.

    2010-01-01

    Changes in water demand associated with population growth and changes in land-use practices in the Pinelands region of southern New Jersey will have a direct effect on stream hydrology. The most pronounced and measurable hydrologic effect is likely to be flow reductions associated with increasing water extraction. Because water-supply needs will continue to grow along with population in the Pinelands area, the goal of maintaining a sustainable balance between the availability of water to protect existing aquatic assemblages while conserving the surficial aquifer for long-term support of human water use needs to be addressed. Although many aquatic fauna have shown resilience and resistance to short-term changes in flows associated with water withdrawals, sustained effects associated with ongoing water-development processes are not well understood. In this study, the U.S. Geological Survey sampled forty-three 100-meter-long stream reaches during high- and low-flow periods across a designed hydrologic gradient ranging from small- (4.1 square kilometers (1.6 square miles)) to medium- (66.3 square kilometers (25.6 square miles)) sized Pinelands stream basins. This design, which uses basin size as a surrogate for water availability, provided an opportunity to evaluate the possible effects of potential variation in stream hydrology on fish and aquatic-invertebrate assemblage response in New Jersey Pinelands streams where future water extraction is expected based on known build-out scenarios. Multiple-regression models derived from extracted non-metric multidimensional scaling axis scores of fish and aquatic invertebrates indicate that some variability in aquatic-assemblage composition across the hydrologic gradient is associated with anthropogenic disturbance, such as urbanization, changes in stream chemistry, and concomitant changes in high-flow runoff patterns. To account for such underlying effects in the study models, any flow parameter or assemblage attribute that

  9. Changes in biogenic and detrital fluxes across the last two glacial terminations at the Shatsky Rise

    Science.gov (United States)

    Bradtmiller, L. I.; Kinsley, C. W.; McGee, D.; Ford, H. L.; Perala-Dewey, J.; Zhang, Y.

    2017-12-01

    The Shatsky Rise is located within strong gradients in SST and biological productivity between the subtropical and subarctic Pacific gyres. The region is highly sensitive to changes in atmospheric and oceanic circulation on glacial-interglacial timescales, which affect the delivery of Fe-bearing dust and other major nutrients, respectively. Here we use a range of proxies in an attempt to determine the effects of changes in westerly winds and gyre boundaries on dust delivery and biological productivity. We present 230Th-normalized fluxes of opal, Corg, CaCO3, and detrital material at ODP Site 1208 over the last two glacial terminations, extending to 145ka. Opal, Corg, and carbonate are products of surface biological productivity, while most detrital material at this site arrives in the form of windborne East Asian dust. In addition, we calculate the concentration of authigenic U as an indicator of relative oxygenation of the sediment water interface. We observe elevated opal and dust fluxes during the last two glacial maxima, and a decrease in both components during deglaciations. Authigenic U shows distinct peaks at the onset of both terminations. The peak at the penultimate deglaciation is also associated with a large peak in opal flux, while the peak in authigenic U during the last termination does not appear to be associated with any large changes in biogenic fluxes. We compare our records with other data from the subtropical-subarctic transition zone, and suggest that our data are consistent with northward shift of the mean position of the westerly jet and subarctic front during deglaciations.

  10. Response of benthic invertebrate communities to a land use ...

    African Journals Online (AJOL)

    ... ranging from continuous tropical montane rain forest to intensive crops and pasture. Streams were sampled in the tropical dry season (October–March) for ... Temperatures in pasture streams were warmer than forest streams (up to 25oC) ...

  11. Seasonality, water quality trends and biological responses in four streams in the Cairngorm Mountains, Scotland

    Directory of Open Access Journals (Sweden)

    C. Soulsby

    2001-01-01

    Full Text Available The chemical composition and invertebrate communities found in four streams in the Cairngorms, Scotland, were monitored between 1985-1997. Stream waters were mildly acidic (mean pH ca. 6.5, with low alkalinity (mean acid neutralising capacity varying from 35-117 meq l-1 and low ionic strength. Subtle differences in the chemistry of each stream were reflected in their invertebrate faunas. Strong seasonality in water chemistry occurred, with the most acid, low alkalinity waters observed during the winter and early spring. This was particularly marked during snowmelt between January and April. In contrast, summer flows were usually groundwater dominated and characterised by higher alkalinity and higher concentrations of most other weathering-derived solutes. Seasonality was also clear in the invertebrate data, with Canonical Correspondence Analysis (CCA separating seasonal samples along axes related to water temperature and discharge characteristics. Inter-annual hydrological and chemical differences were marked, particularly with respect to the winter period. Invertebrate communities found in each of the streams also varied from year to year, with spring communities significantly more variable (PHydrochemical trends over the study period were analysed using a seasonal Kendall test, LOcally WEighted Scatterplot Smoothing (LOWESS and graphical techniques. These indicated that a reduction in sulphate concentrations in stream water is occurring, consistent with declining levels of atmospheric deposition. This may be matched by increases in pH and declining calcium concentrations, though available evidence is inconclusive. Other parameters, such as chloride, total organic carbon and zinc, reveal somewhat random patterns, probably reflecting irregular variations in climatic factors and/or atmospheric deposition. Previous studies have shown that the stream invertebrate communities have remained stable over this period (i.e. no significant linear trends

  12. Logging cuts the functional importance of invertebrates in tropical rainforest.

    Science.gov (United States)

    Ewers, Robert M; Boyle, Michael J W; Gleave, Rosalind A; Plowman, Nichola S; Benedick, Suzan; Bernard, Henry; Bishop, Tom R; Bakhtiar, Effendi Y; Chey, Vun Khen; Chung, Arthur Y C; Davies, Richard G; Edwards, David P; Eggleton, Paul; Fayle, Tom M; Hardwick, Stephen R; Homathevi, Rahman; Kitching, Roger L; Khoo, Min Sheng; Luke, Sarah H; March, Joshua J; Nilus, Reuben; Pfeifer, Marion; Rao, Sri V; Sharp, Adam C; Snaddon, Jake L; Stork, Nigel E; Struebig, Matthew J; Wearn, Oliver R; Yusah, Kalsum M; Turner, Edgar C

    2015-04-13

    Invertebrates are dominant species in primary tropical rainforests, where their abundance and diversity contributes to the functioning and resilience of these globally important ecosystems. However, more than one-third of tropical forests have been logged, with dramatic impacts on rainforest biodiversity that may disrupt key ecosystem processes. We find that the contribution of invertebrates to three ecosystem processes operating at three trophic levels (litter decomposition, seed predation and removal, and invertebrate predation) is reduced by up to one-half following logging. These changes are associated with decreased abundance of key functional groups of termites, ants, beetles and earthworms, and an increase in the abundance of small mammals, amphibians and insectivorous birds in logged relative to primary forest. Our results suggest that ecosystem processes themselves have considerable resilience to logging, but the consistent decline of invertebrate functional importance is indicative of a human-induced shift in how these ecological processes operate in tropical rainforests.

  13. Logging cuts the functional importance of invertebrates in tropical rainforest

    Science.gov (United States)

    Ewers, Robert M.; Boyle, Michael J. W.; Gleave, Rosalind A.; Plowman, Nichola S.; Benedick, Suzan; Bernard, Henry; Bishop, Tom R.; Bakhtiar, Effendi Y.; Chey, Vun Khen; Chung, Arthur Y. C.; Davies, Richard G.; Edwards, David P.; Eggleton, Paul; Fayle, Tom M.; Hardwick, Stephen R.; Homathevi, Rahman; Kitching, Roger L.; Khoo, Min Sheng; Luke, Sarah H.; March, Joshua J.; Nilus, Reuben; Pfeifer, Marion; Rao, Sri V.; Sharp, Adam C.; Snaddon, Jake L.; Stork, Nigel E.; Struebig, Matthew J.; Wearn, Oliver R.; Yusah, Kalsum M.; Turner, Edgar C.

    2015-01-01

    Invertebrates are dominant species in primary tropical rainforests, where their abundance and diversity contributes to the functioning and resilience of these globally important ecosystems. However, more than one-third of tropical forests have been logged, with dramatic impacts on rainforest biodiversity that may disrupt key ecosystem processes. We find that the contribution of invertebrates to three ecosystem processes operating at three trophic levels (litter decomposition, seed predation and removal, and invertebrate predation) is reduced by up to one-half following logging. These changes are associated with decreased abundance of key functional groups of termites, ants, beetles and earthworms, and an increase in the abundance of small mammals, amphibians and insectivorous birds in logged relative to primary forest. Our results suggest that ecosystem processes themselves have considerable resilience to logging, but the consistent decline of invertebrate functional importance is indicative of a human-induced shift in how these ecological processes operate in tropical rainforests. PMID:25865801

  14. Oxytocin mediated behavior in invertebrates: An evolutionary perspective.

    Science.gov (United States)

    Lockard, Meghan A; Ebert, Margaret S; Bargmann, Cornelia I

    2017-02-01

    The molecular and functional conservation of oxytocin-related neuropeptides in behavior is striking. In animals separated by at least 600 million years of evolution, from roundworms to humans, oxytocin homologs play critical roles in the modulation of reproductive behavior and other biological functions. Here, we review the roles of oxytocin in invertebrate behavior from an evolutionary perspective. We begin by tracing the evolution of oxytocin through the invertebrate animal lineages, and then describe common themes in invertebrate behaviors that are mediated by oxytocin-related peptides, including reproductive behavior, learning and memory, food arousal, and predator/prey relationships. Finally, we discuss interesting future directions that have recently become experimentally tractable. Studying oxytocin in invertebrates offers precise insights into the activity of neuropeptides on well-defined neural circuits; the principles that emerge may also be represented in the more complex vertebrate brain. © 2016 Wiley Periodicals, Inc. Develop Neurobiol 77: 128-142, 2017. © 2016 Wiley Periodicals, Inc.

  15. Asellus aquaticus and other invertebrates in drinking water distribution systems

    DEFF Research Database (Denmark)

    Christensen, Sarah Christine

    hygiene. Whereas invertebrates in drinking water are known to host parasites in tropical countries they are largely regarded an aesthetical problem in temperate countries. Publications on invertebrate distribution in Danish systems have been completely absent and while reports from various countries have...... other crustaceans and nematodes protect bacteria from treatment processes. The influence of A. aquaticus has never previously been investigated. Investigations in this PhD project revealed that presence of A. aquaticus did not influence microbial water quality measurably in full scale distribution...... Campylobacter jejuni. Invertebrates enter drinking water systems through various routes e.g. through deficiencies in e.g. tanks, pipes, valves and fittings due to bursts or maintenance works. Some invertebrates pass treatment processes from ground water or surface water supplies while other routes may include...

  16. Guam and the Northern Mariana Islands ESI: INVERT (Invertebrate Polygons)

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — This data set contains sensitive biological resource data for intertidal-, reef-, and mangrove-associated invertebrate species in Guam and the Northern Mariana...

  17. Coastal Resources Atlas: Long Island: INVERT (Invertebrate Polygons)

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — This data set contains sensitive biological resource data for coastal, estuarine, and marine invertebrate species for Long Island, New York. Vector polygons in this...

  18. An investigation into the chemical composition of alternative invertebrate prey

    NARCIS (Netherlands)

    Oonincx, D.G.A.B.; Dierenfeld, E.S.

    2012-01-01

    The aim of this study was to determine the chemical composition of eight invertebrate species and evaluate their suitability as alternative prey. The species selected were rusty red cockroaches (Blatta lateralis), six-spotted cockroaches (Eublaberus distanti), Madagascar hissing cockroaches

  19. Variation in composition of macro-benthic invertebrates as an ...

    African Journals Online (AJOL)

    Mo

    1 Makerere University Institute of Environment & Natural Resources, P.O. Box 7062 Kampala-Uganda ... benthic macro-invertebrates communities were evaluated using GIS techniques along an ...... Kendall Hunt Publishing Company, Iowa.

  20. Various roles of beta-glucan in invertebrates

    Czech Academy of Sciences Publication Activity Database

    Větvička, V.; Šíma, Petr

    2017-01-01

    Roč. 14, č. 1 (2017), s. 488-493 ISSN 1824-307X Institutional support: RVO:61388971 Keywords : invertebrates * glucan * receptors Subject RIV: EC - Immunology OBOR OECD: Immunology Impact factor: 0.824, year: 2016

  1. Effects of neonicotinoids and fipronil on non-target invertebrates.

    Science.gov (United States)

    Pisa, L W; Amaral-Rogers, V; Belzunces, L P; Bonmatin, J M; Downs, C A; Goulson, D; Kreutzweiser, D P; Krupke, C; Liess, M; McField, M; Morrissey, C A; Noome, D A; Settele, J; Simon-Delso, N; Stark, J D; Van der Sluijs, J P; Van Dyck, H; Wiemers, M

    2015-01-01

    We assessed the state of knowledge regarding the effects of large-scale pollution with neonicotinoid insecticides and fipronil on non-target invertebrate species of terrestrial, freshwater and marine environments. A large section of the assessment is dedicated to the state of knowledge on sublethal effects on honeybees (Apis mellifera) because this important pollinator is the most studied non-target invertebrate species. Lepidoptera (butterflies and moths), Lumbricidae (earthworms), Apoidae sensu lato (bumblebees, solitary bees) and the section "other invertebrates" review available studies on the other terrestrial species. The sections on freshwater and marine species are rather short as little is known so far about the impact of neonicotinoid insecticides and fipronil on the diverse invertebrate fauna of these widely exposed habitats. For terrestrial and aquatic invertebrate species, the known effects of neonicotinoid pesticides and fipronil are described ranging from organismal toxicology and behavioural effects to population-level effects. For earthworms, freshwater and marine species, the relation of findings to regulatory risk assessment is described. Neonicotinoid insecticides exhibit very high toxicity to a wide range of invertebrates, particularly insects, and field-realistic exposure is likely to result in both lethal and a broad range of important sublethal impacts. There is a major knowledge gap regarding impacts on the grand majority of invertebrates, many of which perform essential roles enabling healthy ecosystem functioning. The data on the few non-target species on which field tests have been performed are limited by major flaws in the outdated test protocols. Despite large knowledge gaps and uncertainties, enough knowledge exists to conclude that existing levels of pollution with neonicotinoids and fipronil resulting from presently authorized uses frequently exceed the lowest observed adverse effect concentrations and are thus likely to have large

  2. Common mechanisms of synaptic plasticity in vertebrates and invertebrates

    Science.gov (United States)

    Glanzman, David L.

    2016-01-01

    Until recently, the literature on learning-related synaptic plasticity in invertebrates has been dominated by models assuming plasticity is mediated by presynaptic changes, whereas the vertebrate literature has been dominated by models assuming it is mediated by postsynaptic changes. Here I will argue that this situation does not reflect a biological reality and that, in fact, invertebrate and vertebrate nervous systems share a common set of mechanisms of synaptic plasticity. PMID:20152143

  3. A comparative gene expression database for invertebrates

    Directory of Open Access Journals (Sweden)

    Ormestad Mattias

    2011-08-01

    Full Text Available Abstract Background As whole genome and transcriptome sequencing gets cheaper and faster, a great number of 'exotic' animal models are emerging, rapidly adding valuable data to the ever-expanding Evo-Devo field. All these new organisms serve as a fantastic resource for the research community, but the sheer amount of data, some published, some not, makes detailed comparison of gene expression patterns very difficult to summarize - a problem sometimes even noticeable within a single lab. The need to merge existing data with new information in an organized manner that is publicly available to the research community is now more necessary than ever. Description In order to offer a homogenous way of storing and handling gene expression patterns from a variety of organisms, we have developed the first web-based comparative gene expression database for invertebrates that allows species-specific as well as cross-species gene expression comparisons. The database can be queried by gene name, developmental stage and/or expression domains. Conclusions This database provides a unique tool for the Evo-Devo research community that allows the retrieval, analysis and comparison of gene expression patterns within or among species. In addition, this database enables a quick identification of putative syn-expression groups that can be used to initiate, among other things, gene regulatory network (GRN projects.

  4. Chemical elements in invertebrate orders for environmental quality studies

    International Nuclear Information System (INIS)

    Magalhaes, Marcelo R.L.; Franca, Elvis J.; Paiva, Jose D.S.; Hazin, Clovis A.; Fonseca, Felipe Y.; Fernandes, Elisabete A. de Nadai; Bacchi, Marcio A.

    2013-01-01

    Among the biomonitors of environmental quality, there is a lack of studies on using invertebrates to evaluate quantitatively chemical elements in ecosystems. This group of animals is quite numerous, widely distributed and adaptable to the most diverse environmental conditions. These features are very useful for the environmental quality assessment, as well as the several occurring insect-plant interactions performing essential functions in ecosystems. The objective of this work is to study the variability of chemical composition of invertebrate orders for using in environmental quality monitoring studies. Instrumental neutron activation analysis - INAA was applied to determine some nutrients and trace elements in invertebrate samples. Sampling by pitfall traps was carried out in riverine ecosystems from the urban area from the Piracicaba Municipality, State of Sao Paulo, Brazil. Invertebrate and reference material samples were irradiated in the nuclear research reactor IEA-R1, Instituto de Pesquisas Energeticas e Nucleares - IPEN/CNEN. Fragments of a Ni-Cr alloy were irradiated for monitoring the thermal neutron flux. Hymenoptera order was considered the most representative according to the total number of sampled species (about 60%). Significant amounts of Ba, Br, Fe and Sc were found in invertebrates of the order Opiliones. Potassium, rubidium and zinc were highly accumulated in species from Blattodea order, indicating a consistent pattern of accumulation for this invertebrate order. Taking into account the abundance of Hymenoptera order, the chemical composition of its species was significant different at the 95% confidence level for Br and Na in the sampled locals. (author)

  5. Regulation of nitrous oxide emission associated with benthic invertebrates

    DEFF Research Database (Denmark)

    Stief, Peter; Schramm, Andreas

    2010-01-01

    1. A number of freshwater invertebrate species emit N2O, a greenhouse gas that is produced in their gut by denitrifying bacteria (direct N2O emission). Additionally, benthic invertebrate species may contribute to N2O emission from sediments by stimulating denitrification because of their bioirrig......1. A number of freshwater invertebrate species emit N2O, a greenhouse gas that is produced in their gut by denitrifying bacteria (direct N2O emission). Additionally, benthic invertebrate species may contribute to N2O emission from sediments by stimulating denitrification because...... of their bioirrigation behaviour (indirect N2O emission). 2. Two benthic invertebrate species were studied to determine (i) the dependence of direct N2O emission on the preferred diet of the animals, (ii) the regulation of direct N2O emission by seasonally changing factors, such as body size, temperature and NO3...... emitted by benthic invertebrates can be partially consumed in the sediment (E. danica), non-emitting species can still indirectly contribute to total N2O emission from sediment (S. lutaria)....

  6. Chemical elements in invertebrate orders for environmental quality studies

    Energy Technology Data Exchange (ETDEWEB)

    Magalhaes, Marcelo R.L.; Franca, Elvis J.; Paiva, Jose D.S.; Hazin, Clovis A., E-mail: marcelo_rlm@hotmail.com, E-mail: ejfranca@cnen.gov.br, E-mail: dan-paiva@hotmail.com, E-mail: chazin@cnen.gov.br [Centro Regional de Ciencias Nucleares do Nordeste (CRCN-NE/CNEN-PE), Recife, PE (Brazil); Fonseca, Felipe Y.; Fernandes, Elisabete A. de Nadai; Bacchi, Marcio A., E-mail: felipe-yamada@hotmail.com, E-mail: lis@cena.usp.br, E-mail: mabacchi@cena.usp.br [Centro de Energia Nuclear na Agricultura (CENA/USP), Piracicaba, SP (Brazil)

    2013-07-01

    Among the biomonitors of environmental quality, there is a lack of studies on using invertebrates to evaluate quantitatively chemical elements in ecosystems. This group of animals is quite numerous, widely distributed and adaptable to the most diverse environmental conditions. These features are very useful for the environmental quality assessment, as well as the several occurring insect-plant interactions performing essential functions in ecosystems. The objective of this work is to study the variability of chemical composition of invertebrate orders for using in environmental quality monitoring studies. Instrumental neutron activation analysis - INAA was applied to determine some nutrients and trace elements in invertebrate samples. Sampling by pitfall traps was carried out in riverine ecosystems from the urban area from the Piracicaba Municipality, State of Sao Paulo, Brazil. Invertebrate and reference material samples were irradiated in the nuclear research reactor IEA-R1, Instituto de Pesquisas Energeticas e Nucleares - IPEN/CNEN. Fragments of a Ni-Cr alloy were irradiated for monitoring the thermal neutron flux. Hymenoptera order was considered the most representative according to the total number of sampled species (about 60%). Significant amounts of Ba, Br, Fe and Sc were found in invertebrates of the order Opiliones. Potassium, rubidium and zinc were highly accumulated in species from Blattodea order, indicating a consistent pattern of accumulation for this invertebrate order. Taking into account the abundance of Hymenoptera order, the chemical composition of its species was significant different at the 95% confidence level for Br and Na in the sampled locals. (author)

  7. Invertebrate distribution patterns and river typology for the implementation of the water framework directive in Martinique, French Lesser Antilles

    Directory of Open Access Journals (Sweden)

    Bernadet C.

    2013-03-01

    Full Text Available Over the past decade, Europe’s Water Framework Directive provided compelling reasons for developing tools for the biological assessment of freshwater ecosystem health in member States. Yet, the lack of published study for Europe’s overseas regions reflects minimal knowledge of the distribution patterns of aquatic species in Community’s outermost areas. Benthic invertebrates (84 taxa and land-cover, physical habitat and water chemistry descriptors (26 variables were recorded at fifty-one stations in Martinique, French Lesser Antilles. Canonical Correspondence Analysis and Ward’s algorithm were used to bring out patterns in community structure in relation to environmental conditions, and variation partitioning was used to specify the influence of geomorphology and anthropogenic disturbance on invertebrate communities. Species richness decreased from headwater to lowland streams, and species composition changed from northern to southern areas. The proportion of variation explained by geomorphological variables was globally higher than that explained by anthropogenic variables. Geomorphology and land cover played key roles in delineating ecological sub-regions for the freshwater biota. Despite this and the small surface area of Martinique (1080 km2, invertebrate communities showed a clear spatial turnover in composition and biological traits (e.g., insects, crustaceans and molluscs in relation to natural conditions.

  8. Fish and invertebrate flow-biology relationships to support the determination of ecological flows for North Carolina

    Science.gov (United States)

    Phelan, Jennifer; Cuffney, Thomas F.; Patterson, Lauren A.; Eddy, Michele; Dykes, Robert; Pearsall, Sam; Goudreau, Chris; Mead, Jim; Tarver, Fred

    2017-01-01

    A method was developed to characterize fish and invertebrate responses to flow alteration in the state of North Carolina. This method involved using 80th percentile linear quantile regressions to relate six flow metrics to the diversity of riffle-run fish and benthic Ephemeroptera, Plecoptera, and Trichoptera (EPT) richness. All twelve flow-biology relationships were found to be significant, with both benthos and fish showing negative responses to ecodeficits and reductions in flow. The responses of benthic richness to reduced flows were consistent and generally greater than that of fish diversity. However, the riffle-run fish guild showed the greatest reductions in diversity in response to summer ecodeficits. The directional consistency and differential seasonal sensitivities of fish and invertebrates to reductions in flow highlight the need to consider seasonality when managing flows. In addition, all relationships were linear, and therefore do not provide clear thresholds to support ecological flow determinations and flow prescriptions to prevent the degradation of fish and invertebrate communities in North Carolina rivers and streams. A method of setting ecological flows based on the magnitude of change in biological condition that is acceptable to society is explored.

  9. Toxicity, sublethal effects, and potential modes of action of select fungicides on freshwater fish and invertebrates

    Science.gov (United States)

    Elskus, Adria A.

    2012-01-01

    Despite decades of agricultural and urban use of fungicides and widespread detection of these pesticides in surface waters, relatively few data are available on the effects of fungicides on fish and invertebrates in the aquatic environment. Nine fungicides are reviewed in this report: azoxystrobin, boscalid, chlorothalonil, fludioxonil, myclobutanil, fenarimol, pyraclostrobin, pyrimethanil, and zoxamide. These fungicides were identified as emerging chemicals of concern because of their high or increasing global use rates, detection frequency in surface waters, or likely persistence in the environment. A review of the literature revealed significant sublethal effects of fungicides on fish, aquatic invertebrates, and ecosystems, including zooplankton and fish reproduction, fish immune function, zooplankton community composition, metabolic enzymes, and ecosystem processes, such as leaf decomposition in streams, among other biological effects. Some of these effects can occur at fungicide concentrations well below single-species acute lethality values (48- or 96-hour concentration that effects a response in 50 percent of the organisms, that is, effective concentration killing 50 percent of the organisms in 48 or 96 hours) and chronic sublethal values (for example, 21-day no observed adverse effects concentration), indicating that single-species toxicity values may dramatically underestimate the toxic potency of some fungicides. Fungicide modes of toxic action in fungi can sometimes reflect the biochemical and (or) physiological effects of fungicides observed in vertebrates and invertebrates; however, far more studies are needed to explore the potential to predict effects in nontarget organisms based on specific fungicide modes of toxic action. Fungicides can also have additive and (or) synergistic effects when used with other fungicides and insecticides, highlighting the need to study pesticide mixtures that occur in surface waters. For fungicides that partition to

  10. StreamCat

    Data.gov (United States)

    U.S. Environmental Protection Agency — The StreamCat Dataset provides summaries of natural and anthropogenic landscape features for ~2.65 million streams, and their associated catchments, within the...

  11. Prioritized Contact Transport Stream

    Science.gov (United States)

    Hunt, Walter Lee, Jr. (Inventor)

    2015-01-01

    A detection process, contact recognition process, classification process, and identification process are applied to raw sensor data to produce an identified contact record set containing one or more identified contact records. A prioritization process is applied to the identified contact record set to assign a contact priority to each contact record in the identified contact record set. Data are removed from the contact records in the identified contact record set based on the contact priorities assigned to those contact records. A first contact stream is produced from the resulting contact records. The first contact stream is streamed in a contact transport stream. The contact transport stream may include and stream additional contact streams. The contact transport stream may be varied dynamically over time based on parameters such as available bandwidth, contact priority, presence/absence of contacts, system state, and configuration parameters.

  12. Diet of the crayfish Paranephrops zealandicus in bush and pasture streams : insights from stable isotopes and stomach analysis

    International Nuclear Information System (INIS)

    Hollows, J.W.; Townsend, C.R.; Collier, K.J.

    2002-01-01

    Crayfish (Paranephrops zealandicus White) stomachs from streams in both native bush (mainly tree leaves and dicotyledonous seeds) and exotic pasture settings (mainly grass stems and monocotyledonous seeds) were dominated by allochthonous material. More detritus occurred in stomachs in autumn-winter than in spring-summer, but quantities were similar in crayfish from native bush and pasture streams. The stomachs of larger crayfish contained a significantly greater proportion of detritus than smaller individuals. Aquatic invertebrates were the second most abundant dietary category by volume, with highest values in winter, but there were no significant differences between land uses or crayfish size classes. A wide range of invertebrates was eaten by crayfish, with mayfly nymphs, chironomid larvae, and snails predominating. The latter were numerically more prominent in crayfish from bush than pasture streams. Terrestrial invertebrates were recorded from 4% of stomachs, but there were no significant differences in relation to land use, season, or crayfish size class. Despite aquatic invertebrates making up 13 C and perhaps of microfloral origin, seems to be an important energy source for crayfish in both stream types. (author). 52 refs., 5 figs., 2 tabs

  13. Carbon Cycling in Floodplain Ecosystems: Out-Gassing and Photosynthesis Transmit Soil d13C Gradient Through Stream Food Webs

    DEFF Research Database (Denmark)

    Gray, Duncan P.; Harding, Jon S.; Elberling, Bo

    2011-01-01

    Natural braided river floodplains typically possess high groundwater–surface water exchange, which is vital to the overall function and structure of these complex ecosystems. Spring-fed streams on the floodplain are also hotspots of benthic invertebrate diversity and productivity. The sources of ...

  14. You are not always what we think you eat: selective assimilation across multiple whole-stream isotopic tracer studies

    Science.gov (United States)

    W. K. Dodds; S. M. Collins; S. K. Hamilton; J. L. Tank; S. Johnson; J. R. Webster; K. S. Simon; M. R. Whiles; H. M. Rantala; W. H. McDowell; S. D. Peterson; T. Riis; C. L. Crenshaw; S. A. Thomas; P. B. Kristensen; B. M. Cheever; A. S. Flecker; N. A. Griffiths; T. Crowl; E. J. Rosi-Marshall; R. El-Sabaawi; E. Martí

    2014-01-01

    Analyses of 21 15N stable isotope tracer experiments, designed to examine food web dynamics in streams around the world, indicated that the isotopic composition of food resources assimilated by primary consumers (mostly invertebrates) poorly reflected the presumed food sources. Modeling indicated that consumers assimilated only 33–50% of the N...

  15. Importance of terrestrial arthropods as subsidies in lowland Neotropical rain forest stream ecosystems

    Science.gov (United States)

    Small, Gaston E.; Torres, Pedro J.; Schwizer, Lauren M.; Duff, John H.; Pringle, Catherine M.

    2013-01-01

    The importance of terrestrial arthropods has been documented in temperate stream ecosystems, but little is known about the magnitude of these inputs in tropical streams. Terrestrial arthropods falling from the canopy of tropical forests may be an important subsidy to tropical stream food webs and could also represent an important flux of nitrogen (N) and phosphorus (P) in nutrient-poor headwater streams. We quantified input rates of terrestrial insects in eight streams draining lowland tropical wet forest in Costa Rica. In two focal headwater streams, we also measured capture efficiency by the fish assemblage and quantified terrestrially derived N- and P-excretion relative to stream nutrient uptake rates. Average input rates of terrestrial insects ranged from 5 to 41 mg dry mass/m2/d, exceeding previous measurements of aquatic invertebrate secondary production in these study streams, and were relatively consistent year-round, in contrast to values reported in temperate streams. Terrestrial insects accounted for half of the diet of the dominant fish species, Priapicthys annectens. Although terrestrially derived fish excretion was found to be a small flux relative to measured nutrient uptake rates in the focal streams, the efficient capture and processing of terrestrial arthropods by fish made these nutrients available to the local stream ecosystem. This aquatic-terrestrial linkage is likely being decoupled by deforestation in many tropical regions, with largely unknown but potentially important ecological consequences.

  16. Local geology determines responses of stream producers and fungal decomposers to nutrient enrichment: A field experiment.

    Science.gov (United States)

    Mykrä, Heikki; Sarremejane, Romain; Laamanen, Tiina; Karjalainen, Satu Maaria; Markkola, Annamari; Lehtinen, Sirkku; Lehosmaa, Kaisa; Muotka, Timo

    2018-04-16

    We examined how short-term (19 days) nutrient enrichment influences stream fungal and diatom communities, and rates of leaf decomposition and algal biomass accrual. We conducted a field experiment using slow-releasing nutrient pellets to increase nitrate (NO 3 -N) and phosphate (PO 4 -P) concentrations in a riffle section of six naturally acidic (naturally low pH due to catchment geology) and six circumneutral streams. Nutrient enrichment increased microbial decomposition rate on average by 14%, but the effect was significant only in naturally acidic streams. Nutrient enrichment also decreased richness and increased compositional variability of fungal communities in naturally acidic streams. Algal biomass increased in both stream types, but algal growth was overall very low. Diatom richness increased in response to nutrient addition by, but only in circumneutral streams. Our results suggest that primary producers and decomposers are differentially affected by nutrient enrichment and that their responses to excess nutrients are context dependent, with a potentially stronger response of detrital processes and fungal communities in naturally acidic streams than in less selective environments.

  17. Investigating high zircon concentrations in the fine fraction of stream sediments draining the Pan-African Dahomeyan Terrane in Nigeria

    International Nuclear Information System (INIS)

    Key, Roger M.; Johnson, Christopher C.; Horstwood, Matthew S.A.; Lapworth, Dan J.; Knights, Katherine V.; Kemp, Simon J.; Watts, Michael; Gillespie, Martin; Adekanmi, Michael; Arisekola, Tunde

    2012-01-01

    Sixteen hundred stream sediments (<150 μm fraction) collected during regional geochemical surveys in central and SW Nigeria have high median and maximum concentrations of Zr that exceed corresponding Zr concentrations found in stream sediments collected from elsewhere in the World with similar bedrock geology. X-ray diffraction studies on a sub-set of the analysed stream sediments showed that Zr is predominantly found in detrital zircon grains. However, the main proximal source rocks (Pan-African ‘Older Granites’ of Nigeria and their Proterozoic migmatitic gneiss country rocks) are not enriched in zircon (or Zr). Nevertheless, U–Pb LA-ICP-MS dating with cathodoluminescence imaging on detrital zircons, both from stream sediment samples and underlying Pan-African ‘Older Granites’ confirms a local bedrock source for the stream sediment zircons. A combination of tropical/chemical weathering and continuous physical weathering, both by ‘wet season’ flash flooding and ‘dry season’ unidirectional winds are interpreted to have effectively broken down bedrock silicate minerals and removed much of the resultant clay phases, thereby increasing the Zr contents in stream sediments. The strong correlation between winnowing index (Th/Al) and Zr concentration across the study area support this interpretation. Therefore, ‘anomalous’ high values of Zr, as well as other elements concentrated in resistant ‘heavy’ minerals in Nigeria’s streams may not reflect proximal bedrock concentrations of these elements. This conclusion has important implications for using stream sediment chemistry as an exploration tool in Nigeria for primary metal deposits associated with heavy minerals.

  18. Invertebrate metacommunity structure and dynamics in an andean glacial stream network facing climate change

    DEFF Research Database (Denmark)

    Cauvy-Fraunié, Sophie; Espinosa, Rodrigo; Andino, Patricio

    2015-01-01

    .g., overland, watercourse, and downstream directional dispersal) in organizing the aquatic metacommunity. Results revealed that both environmental and spatial variables significantly explained community variation among sites. Among all environmental variables, the glacial influence component best explained...... macroinvertebrate metacommunity structure in many ways. Indeed, the harsh environmental conditions characterizing glacial influence not only constitute the primary environmental filter but also, limit water-borne macroinvertebrate dispersal. Therefore, glacier runoff acts as an aquatic dispersal barrier, isolating...

  19. Productivity of Stream Definitions

    NARCIS (Netherlands)

    Endrullis, Jörg; Grabmayer, Clemens; Hendriks, Dimitri; Isihara, Ariya; Klop, Jan

    2007-01-01

    We give an algorithm for deciding productivity of a large and natural class of recursive stream definitions. A stream definition is called ‘productive’ if it can be evaluated continuously in such a way that a uniquely determined stream is obtained as the limit. Whereas productivity is undecidable

  20. Productivity of stream definitions

    NARCIS (Netherlands)

    Endrullis, J.; Grabmayer, C.A.; Hendriks, D.; Isihara, A.; Klop, J.W.

    2008-01-01

    We give an algorithm for deciding productivity of a large and natural class of recursive stream definitions. A stream definition is called ‘productive’ if it can be evaluated continually in such a way that a uniquely determined stream in constructor normal form is obtained as the limit. Whereas

  1. Pyrethroid insecticides in urban salmon streams of the Pacific Northwest

    Energy Technology Data Exchange (ETDEWEB)

    Weston, D.P., E-mail: dweston@berkeley.edu [Department of Integrative Biology, University of California, 3060 Valley Life Sciences Bldg., Berkeley, CA 94720-3140 (United States); Asbell, A.M., E-mail: aasbell@berkeley.edu [Department of Integrative Biology, University of California, 3060 Valley Life Sciences Bldg., Berkeley, CA 94720-3140 (United States); Hecht, S.A., E-mail: scott.hecht@noaa.gov [NOAA Fisheries, Office of Protected Resources, 510 Desmond Drive S.E., Lacey, WA 98503 (United States); Scholz, N.L., E-mail: nathaniel.scholz@noaa.gov [NOAA Fisheries, Northwest Fisheries Science Center, 2725 Montlake Blvd. E., Seattle, WA 98112 (United States); Lydy, M.J., E-mail: mlydy@siu.edu [Fisheries and Illinois Aquaculture Center and Department of Zoology, Southern Illinois University, 171 Life Sciences II, Carbondale, IL 62901 (United States)

    2011-10-15

    Urban streams of the Pacific Northwest provide spawning and rearing habitat for a variety of salmon species, and food availability for developing salmon could be adversely affected by pesticide residues in these waterbodies. Sediments from Oregon and Washington streams were sampled to determine if current-use pyrethroid insecticides from residential neighborhoods were reaching aquatic habitats, and if they were at concentrations acutely toxic to sensitive invertebrates. Approximately one-third of the 35 sediment samples contained measurable pyrethroids. Bifenthrin was the pyrethroid of greatest concern with regards to aquatic life toxicity, consistent with prior studies elsewhere. Toxicity to Hyalella azteca and/or Chironomus dilutus was found in two sediment samples at standard testing temperature (23 deg. C), and in one additional sample at a more environmentally realistic temperature (13 deg. C). Given the temperature dependency of pyrethroid toxicity, low temperatures typical of northwest streams can increase the potential for toxicity above that indicated by standard testing protocols. - Highlights: > Salmon-bearing creeks can be adversely impacted by insecticides from urban runoff. > Pyrethroid insecticides were found in one-third of the creeks in Washington and Oregon. > Two creeks contained concentrations acutely lethal to sensitive invertebrates. > Bifenthrin was of greatest concern, though less than in prior studies. > Standard toxicity testing underestimates the ecological risk of pyrethroids. - Pyrethroid insecticides are present in sediments of urban creeks of Oregon and Washington, though less commonly than in studies elsewhere in the U.S.

  2. Pyrethroid insecticides in urban salmon streams of the Pacific Northwest

    International Nuclear Information System (INIS)

    Weston, D.P.; Asbell, A.M.; Hecht, S.A.; Scholz, N.L.; Lydy, M.J.

    2011-01-01

    Urban streams of the Pacific Northwest provide spawning and rearing habitat for a variety of salmon species, and food availability for developing salmon could be adversely affected by pesticide residues in these waterbodies. Sediments from Oregon and Washington streams were sampled to determine if current-use pyrethroid insecticides from residential neighborhoods were reaching aquatic habitats, and if they were at concentrations acutely toxic to sensitive invertebrates. Approximately one-third of the 35 sediment samples contained measurable pyrethroids. Bifenthrin was the pyrethroid of greatest concern with regards to aquatic life toxicity, consistent with prior studies elsewhere. Toxicity to Hyalella azteca and/or Chironomus dilutus was found in two sediment samples at standard testing temperature (23 deg. C), and in one additional sample at a more environmentally realistic temperature (13 deg. C). Given the temperature dependency of pyrethroid toxicity, low temperatures typical of northwest streams can increase the potential for toxicity above that indicated by standard testing protocols. - Highlights: → Salmon-bearing creeks can be adversely impacted by insecticides from urban runoff. → Pyrethroid insecticides were found in one-third of the creeks in Washington and Oregon. → Two creeks contained concentrations acutely lethal to sensitive invertebrates. → Bifenthrin was of greatest concern, though less than in prior studies. → Standard toxicity testing underestimates the ecological risk of pyrethroids. - Pyrethroid insecticides are present in sediments of urban creeks of Oregon and Washington, though less commonly than in studies elsewhere in the U.S.

  3. Indication of pesticide effects and recolonization in streams.

    Science.gov (United States)

    Knillmann, Saskia; Orlinskiy, Polina; Kaske, Oliver; Foit, Kaarina; Liess, Matthias

    2018-07-15

    The agricultural use of pesticides leads to environmentally relevant pesticide concentrations that cause adverse effects on stream ecosystems. These effects on invertebrate community composition can be identified by the bio-indicator SPEAR pesticides . However, refuge areas have been found to partly confound the indicator. On the basis of three monitoring campaigns of 41 sites in Central Germany, we identified 11 refuge taxa. The refuge taxa, mainly characterized by dispersal-based resilience, were observed only nearby uncontaminated stream sections and independent of the level of pesticide pressure. Through incorporation of this information into the revised SPEAR pesticides indicator, the community structure specifically identified the toxic pressure and no longer depended on the presence of refuge areas. With regard to ecosystem functions, leaf litter degradation was predicted by the revised SPEAR pesticides and the median water temperature at a site (R 2  = 0.38, P = 0.003). Furthermore, we designed the bio-indicator SPEAR refuge to quantify the magnitude of general recolonization at a given stream site. We conclude that the taxonomic composition of aquatic invertebrate communities enables a specific indication of anthropogenic stressors and resilience of ecosystems. Copyright © 2018 Elsevier B.V. All rights reserved.

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

    Directory of Open Access Journals (Sweden)

    MARY N. J.

    2002-01-01

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

  5. Trace-element and Nd-isotope systematics in detrital apatite of the Po river catchment: Implications for provenance discrimination and the lag-time approach to detrital thermochronology

    Science.gov (United States)

    Malusà, Marco G.; Wang, Jiangang; Garzanti, Eduardo; Liu, Zhi-Chao; Villa, Igor M.; Wittmann, Hella

    2017-10-01

    Detrital thermochronology is often employed to assess the evolutionary stage of an entire orogenic belt using the lag-time approach, i.e., the difference between the cooling and depositional ages of detrital mineral grains preserved in a stratigraphic succession. The impact of different eroding sources to the final sediment sink is controlled by several factors, including the short-term erosion rate and the mineral fertility of eroded bedrock. Here, we use apatite fertility data and cosmogenic-derived erosion rates in the Po river catchment (Alps-Apennines) to calculate the expected percentage of apatite grains supplied to the modern Po delta from the major Alpine and Apenninic eroding sources. We test these predictions by using a cutting-edge dataset of trace-element and Nd-isotope signatures on 871 apatite grains from 14 modern sand samples, and we use apatite fission-track data to validate our geochemical approach to provenance discrimination. We found that apatite grains shed from different sources are geochemically distinct. Apatites from the Lepontine dome in the Central Alps show relative HREE enrichment, lower concentrations in Ce and U, and higher 147Sm/144Nd ratios compared to apatites derived from the External Massifs. Derived provenance budgets point to a dominant apatite contribution to the Po delta from the high-fertility Lepontine dome, consistent with the range independently predicted from cosmonuclide and mineral-fertility data. Our results demonstrate that the single-mineral record in the final sediment sink can be largely determined by high-fertility source rocks exposed in rapidly eroding areas within the drainage. This implies that the detrital thermochronology record may reflect processes affecting relatively small parts of the orogenic system under consideration. A reliable approach to lag-time analysis would thus benefit from an independent provenance discrimination of dated mineral grains, which may allow to proficiently reconsider many

  6. Physical data and biological data for algae, aquatic invertebrates, and fish from selected reaches on the Carson and Truckee rivers, Nevada and California, 1993-97

    Science.gov (United States)

    Lawrence, S.J.; Seiler, R.L.

    2002-01-01

    This report, a product of the National Water- Quality Assessment Program, is a compilation of physical data and biological data for algae, aquatic invertebrates, and fish collected in the Carson and Truckee River Basins, Nevada and California. Most of the data were collected between 1993 and 1996 at selected reaches on the Carson and Truckee Rivers. Algae and aquatic invertebrate samples were collected from cobble riffles, submerged woody-snag habitats, and from depositional areas such as pools. Between 1993 and 1996, fish and crayfish were collected from all wadeable habitats at each of seven basic-fixed sites using either electroshocking methods or seining. Additional fish and crayfish were collected at one site on the Truckee River in 1997. Fish were identified to species, measured for total and standard length, checked for anomalies, and weighed at the collection site. Fish were returned to the stream after measurements were taken. Measurements of water depth, stream velocity, determinations of substrate type and substrate embeddedness were made at each sampling site. Algae and aquatic invertebrate samples were sent to the U.S. Geological Survey National Water-Quality Laboratory for identification and enumeration. A total of 103 semi-quantitative and 55 qualitative algae samples were collected at 20 river reaches on the Carson and Truckee Rivers between 1993 and 1996. These samples represent algae in cobble riffles, on submerged woody snags, and on sediment surfaces in depositional areas. In those 158 samples, 514 algal species, varieties, or forms were identified. Of the 8 algal phyla represented, the diatoms (Phylum Bacillariophyta) were the most abundant with 351 species, varieties, or forms. The green algae (Phylum Chlorophyta) were next in abundance with 108 species, varieties, or forms followed by the blue-green algae (Phylum Cyanophyta) with 41 species, varieties, or forms. A total of 49 semi-quantitative aquatic invertebrate samples were collected at 27

  7. ASSESSMENT OF RIVER WATER QUALITY USING MACRO-INVERTEBRATES AS INDICATORS: A CASE STUDY OF BHALU KHOLA TRIBUTARY, BUDHIGANDAKI RIVER, GORKHA, NEPAL

    Directory of Open Access Journals (Sweden)

    Anju Rana

    2015-08-01

    Full Text Available  Macroinvertebrates are widely considered as indicators of water quality. The present research work was conducted in Bhalu khola, a tributary of Budhigandaki River, Nepal, to identify water quality using macro invertebrates with Nepalese Biotic Score (NEPBIOS, and examine its applicability by comparing with Water Quality Index (WQI.The diversity of macro invertebrates in the studied river was high as depicted by Shannon Wiener Diversity Index. Altogether, 103 macro invertebrates were identified from 11 families and five orders. There were no dominant species, and most of the species were in clumped distribution. According to NEPBIOS index, river water was found to comply with the characteristics of WQ class I-II that means water quality of the river was good. Other indices such as Hilsenhoff and Lincoln quality index (LQI index also supported this result. Similarly, water quality index (WQI also showed similarity with NEPBIOS index, indicating water appropriate for drinking purpose. Thus, it is concluded that the macro invertebrates can be used as economic tools for determining water quality of streams and rivers as efficient water quality indicators.International Journal of Environment Volume-4, Issue-3, June-August 2015Page: 55-68

  8. Combined effects of local habitat, anthropogenic stress, and dispersal on stream ecosystems: a mesocosm experiment.

    Science.gov (United States)

    Turunen, Jarno; Louhi, Pauliina; Mykrä, Heikki; Aroviita, Jukka; Putkonen, Emmi; Huusko, Ari; Muotka, Timo

    2018-06-06

    The effects of anthropogenic stressors on community structure and ecosystem functioning can be strongly influenced by local habitat structure and dispersal from source communities. Catchment land uses increase the input of fine sediments into stream channels, clogging the interstitial spaces of benthic habitats. Aquatic macrophytes enhance habitat heterogeneity and mediate important ecosystem functions, being thus a key component of habitat structure in many streams. Therefore, the recovery of macrophytes following in-stream habitat modification may be prerequisite for successful stream restoration. Restoration success is also affected by dispersal of organisms from the source community, with potentially strongest responses in relatively isolated headwater sites that receive limited amount of dispersing individuals. We used a factorial design in a set of stream mesocosms to study the independent and combined effects of an anthropogenic stressor (sand sedimentation), local habitat (macrophytes, i.e. moss transplants) and enhanced dispersal (two levels: high vs. low) on organic matter retention, algal accrual rate, leaf decomposition and macroinvertebrate community structure. Overall, all responses were simple additive effects with no interactions between treatments. Sand reduced algal accumulation, total invertebrate density and density of a few individual taxa. Mosses reduced algal accrual rate and algae-grazing invertebrates, but enhanced organic matter retention and detritus- and filter-feeders. Mosses also reduced macroinvertebrate diversity by increasing the dominance by a few taxa. Mosses also reduced leaf-mass loss, possibly because the organic matter retained by mosses provided an additional food source for leaf-shredding invertebrates and thus reduced shredder aggregation into leaf packs. The effect of mosses on macroinvertebrate communities and ecosystem functioning was distinct irrespective of the level of dispersal, suggesting strong environmental

  9. A generalized model for estimating the energy density of invertebrates

    Science.gov (United States)

    James, Daniel A.; Csargo, Isak J.; Von Eschen, Aaron; Thul, Megan D.; Baker, James M.; Hayer, Cari-Ann; Howell, Jessica; Krause, Jacob; Letvin, Alex; Chipps, Steven R.

    2012-01-01

    Invertebrate energy density (ED) values are traditionally measured using bomb calorimetry. However, many researchers rely on a few published literature sources to obtain ED values because of time and sampling constraints on measuring ED with bomb calorimetry. Literature values often do not account for spatial or temporal variability associated with invertebrate ED. Thus, these values can be unreliable for use in models and other ecological applications. We evaluated the generality of the relationship between invertebrate ED and proportion of dry-to-wet mass (pDM). We then developed and tested a regression model to predict ED from pDM based on a taxonomically, spatially, and temporally diverse sample of invertebrates representing 28 orders in aquatic (freshwater, estuarine, and marine) and terrestrial (temperate and arid) habitats from 4 continents and 2 oceans. Samples included invertebrates collected in all seasons over the last 19 y. Evaluation of these data revealed a significant relationship between ED and pDM (r2  =  0.96, p cost savings compared to traditional bomb calorimetry approaches. This model should prove useful for a wide range of ecological studies because it is unaffected by taxonomic, seasonal, or spatial variability.

  10. Lysosomal enzymes and their receptors in invertebrates: an evolutionary perspective.

    Science.gov (United States)

    Kumar, Nadimpalli Siva; Bhamidimarri, Poorna M

    2015-01-01

    Lysosomal biogenesis is an important process in eukaryotic cells to maintain cellular homeostasis. The key components that are involved in the biogenesis such as the lysosomal enzymes, their modifications and the mannose 6-phosphate receptors have been well studied and their evolutionary conservation across mammalian and non-mammalian vertebrates is clearly established. Invertebrate lysosomal biogenesis pathway on the other hand is not well studied. Although, details on mannose 6-phosphate receptors and enzymes involved in lysosomal enzyme modifications were reported earlier, a clear cut pathway has not been established. Recent research on the invertebrate species involving biogenesis of lysosomal enzymes suggests a possible conserved pathway in invertebrates. This review presents certain observations based on these processes that include biochemical, immunological and functional studies. Major conclusions include conservation of MPR-dependent pathway in higher invertebrates and recent evidence suggests that MPR-independent pathway might have been more prominent among lower invertebrates. The possible components of MPR-independent pathway that may play a role in lysosomal enzyme targeting are also discussed here.

  11. Piscicides and invertebrates: after 70 years, does anyone really know?

    Science.gov (United States)

    Vinson, M.R.; Dinger, E.C.; Vinson, D.K.

    2010-01-01

    The piscicides rotenone and antimycin have been used for more than 70 years to manage fish populations by eliminating undesirable fish species. The effects of piscicides on aquatic invertebrate assemblages are considered negligible by some and significant by others. This difference of opinion has created contentious situations and delayed native fish restoration projects. We review the scientific evidence and report that short-term ( 1 year) impacts are largely unknown. Recovery of invertebrate assemblages following treatments ranged from a few months for abundances of common taxa to several years for rarer taxa. Variation in reported effects was primarily due to natural variation among species and habitats and a lack of adequate pre- and post-treatment sampling which prevents determining the true impacts to invertebrate assemblages. The factors most likely to influence impacts and recovery of aquatic invertebrate assemblages following piscicide treatments are: (1) concentration, duration, and breadth of the piscicide treatment; (2) invertebrate morphology and life history characteristics, including surface area to volume ratios, type of respiration organs, generation time, and propensity to disperse; (3) refugia presence; and (4) distance from colonization sources.

  12. Recovery of a mining-damaged stream ecosystem

    Science.gov (United States)

    Mebane, Christopher A.; Eakins, Robert J.; Fraser, Brian G.; Adams, William J.

    2015-01-01

    This paper presents a 30+ year record of changes in benthic macroinvertebrate communities and fish populations associated with improving water quality in mining-influenced streams. Panther Creek, a tributary to the Salmon River in central Idaho, USA suffered intensive damage from mining and milling operations at the Blackbird Mine that released copper (Cu), arsenic (As), and cobalt (Co) into tributaries. From the 1960s through the 1980s, no fish and few aquatic invertebrates could be found in 40 km of mine-affected reaches of Panther Creek downstream of the metals contaminated tributaries, Blackbird and Big Deer Creeks.

  13. The White Nile as a source for Nile sediments: Assessment using U-Pb geochronology of detrital rutile and monazite

    Science.gov (United States)

    Be'eri-Shlevin, Yaron; Avigad, Dov; Gerdes, Axel

    2018-04-01

    Basement terranes exposed at the headwaters of the White Nile include Archean-Paleoproterozoic rocks of the Congo Craton, whose northern sectors were severely reworked during Neoproterozoic orogeny. New U-Pb analyses of detrital rutile and monazite from early Quaternary to Recent coastal quartz sands of Israel, at the northeast extension of the Nile sedimentary system, yield mostly late Neoproterozoic ages, with a dominant peak at ca. 600 Ma. While derivation from the reworked sectors of the Craton cannot be negated, the absence of pre-Neoproterozoic rutile and monazite indicates that the detrital contribution from the Congo cratonic nuclei into the main Nile was insignificant. The near absence of White Nile basement-derived heavy minerals from the Nile sands arriving at the Eastern Mediterranean may be explained by a number of factors such as relatively minor erosion of the Cratonic basement nuclei during the Quaternary, late connection of the White Nile to the main Nile system with a possibility that northern segments connected prior to more southerly ones, and a long-term effective sediment blockage mechanism at the mouth of White Nile. Likewise, our previous study demonstrated that Nile sands display a detrital zircon U-Pb-Hf pattern consistent with significant recycling of NE African Paleozoic sediments. It is thus plausible that any detrital contribution from White Nile basement rocks was thoroughly diluted by eroded Paleozoic sediments, or their recycled products, which were likely the greatest sand reservoir in the region. This study adds to previous studies showing the advantage of a multi mineral U-Pb geochronology strategy in constraining sediment provenance patterns.

  14. Late Permian rivers draining the uplifted Cape Fold Belt: magnetostratigraphy and detrital thermochronology of Karoo Basin sediments

    Science.gov (United States)

    Tohver, E.; Schmieder, M.; Arosio, R.; Lanci, L.; Jourdan, F.; Wilson, A.; Ratcliffe, K.; Payenberg, T.; Flint, S.

    2017-12-01

    The Cape Fold Belt and Karoo Basin of southern Africa formed during the Permian orogeny that affected the 13,000 km southern margin of the Gondwanan continent. In this report, we synthesize new and recent magnetostratigraphic and geochronologic data to establish a chronostratigraphic framework for Karoo Basin sedimentation for comparison with the thermal/exhumation history of the Cape Fold Belt. The source-sink model is evaluated using new data from detrital muscovite and zircon from 2 km composite section of fluvial sandstone and mudstones deposited at ca.275 - 260 Ma. Coherent age populations of detrital zircon grains indicate rapid incorporation of contemporary volcanic ashbeds into the sedimentary record. In contrast, cooling age distributions of detrital muscovite are typically ca. 5 - 10 Ma older than the age of deposition; similar lag times are observed from modern sediments in active mountain belts. Trace element geochemical signatures demonstrate a clear shift towards crustal recycling via headland erosion in the Beaufort Group relative to the underlying Ecca Group. These observations pinpoint the age of uplift for the Cape Fold Belt, which began to function as the major sediment source for the foreland Karoo Basin with the deposition of the uppermost Ecca Group and basal Beaufort Group.

  15. Detrital zircon ages in Buller and Takaka terranes, New Zealand : constraints on early Zealandia history

    International Nuclear Information System (INIS)

    Adams, C.J.; Mortimer, N.; Campbell, H.J.; Griffin, W.L.

    2015-01-01

    Detrital zircon ages are presented for 34 early Palaeozoic sandstones from Buller and Takaka terranes, New Zealand, and formerly adjacent parts of Australia-Antarctica. The Buller-Takaka datasets always have two major groups: Ordovician-late Neoproterozoic, 444-700 Ma (but mainly 540-700 Ma), termed 'Gondwana Assembly' (GA), and early Neoproterozoic-Mesoproterozoic, 700-1600 Ma (but mainly 900-1200 Ma), termed 'Rodinia Assembly' (RA). In both terranes, significant age components within these groups are strikingly similar and also have RA/GA ratios, 0.6-1.8. The Cambrian volcanic arc of the Takaka Terrane has contributed little to the zircon patterns. Proportions of Late Cambrian-Early Ordovician zircons, characteristic of granitoid sources in the Ross-Delamerian Orogen are low. The zircons are predominantly reworked with contemporary zircons only evident in a few Buller datasets. The zircon patterns suggest that two major sources (late Mesoproterozoic and late Neoproterozoic), enduring over 120 Ma, were widely distributed and it is postulated they form Precambrian basement beneath southern Zealandia. (author).

  16. The use of invertebrates as indicators of environmental change in alpine rivers and lakes

    International Nuclear Information System (INIS)

    Khamis, K.; Hannah, D.M.; Brown, L.E.; Tiberti, R.; Milner, A.M.

    2014-01-01

    In alpine regions climatic change will alter the balance between water sources (rainfall, ice-melt, snowmelt, and groundwater) for aquatic systems, particularly modifying the relative contributions of meltwater, groundwater and rain to both rivers and lakes. While these changes are expected to have implications for alpine aquatic ecosystems, little is known about potential ecological tipping points and associated indicator taxa. We examined changes in biotic communities along a gradient of glacier influence for two study systems: (1) a stream network in the French Pyrénées; and (2) a network of lakes in the Italian Alps, with the aim of identifying potential indicator taxa (macroinvertebrates and zooplankton) of glacier retreat in these environments. To assess parallels in biotic responses across streams and lakes, both primary data and findings from other publications were synthesised. Using TITAN (Threshold Indicator Taxa ANalysis) changes in community composition of river taxa were identified at thresholds of < 5.1% glacier cover and < 66.6% meltwater contribution. Below these thresholds the loss of cold stenothermic benthic invertebrate taxa, Diamesa spp. and the Pyrenean endemic Rhyacophila angelieri was apparent. Some generalist taxa including Protonemura sp., Perla grandis, Baetis alpinus, Rhithrogena loyolaea and Microspectra sp. increased when glacier cover was < 2.7% and < 52% meltwater. Patterns were not as distinct for the alpine lakes, due to fewer sampling sites; however, Daphnia longispina grp. and the benthic invertebrate groups Plectopera and Planaria were identified as potential indicator taxa. While further work is required to assess potential indicator taxa for alpine lake systems, findings from alpine river systems were consistent between methods for assessing glacier influence (meltwater contribution/glacier cover). Hence, it is clear that TITAN could become a useful management tool, enabling: (i) the identification of taxa particularly

  17. The use of invertebrates as indicators of environmental change in alpine rivers and lakes

    Energy Technology Data Exchange (ETDEWEB)

    Khamis, K.; Hannah, D.M. [School of Geography Earth and Environmental Science, University of Birmingham, Birmingham B15 2TT (United Kingdom); Brown, L.E. [School of Geography/water@leeds, University of Leeds, Woodhouse Lane, Leeds LS2 9JT (United Kingdom); Tiberti, R. [DSTA, Dipartimento di Scienze della Terra e dell' Ambiente, University of Pavia, Via Ferrata 9, 27100 Pavia (Italy); Alpine Wildlife Research Centre, Gran Paradiso National Park, Degioz 11, I-1101 Valsavarenche, Aosta (Italy); Milner, A.M., E-mail: a.m.milner@bham.ac.uk [School of Geography Earth and Environmental Science, University of Birmingham, Birmingham B15 2TT (United Kingdom); Institute of Arctic Biology, University of Alaska, Fairbanks, AK 99775 (United States)

    2014-09-15

    In alpine regions climatic change will alter the balance between water sources (rainfall, ice-melt, snowmelt, and groundwater) for aquatic systems, particularly modifying the relative contributions of meltwater, groundwater and rain to both rivers and lakes. While these changes are expected to have implications for alpine aquatic ecosystems, little is known about potential ecological tipping points and associated indicator taxa. We examined changes in biotic communities along a gradient of glacier influence for two study systems: (1) a stream network in the French Pyrénées; and (2) a network of lakes in the Italian Alps, with the aim of identifying potential indicator taxa (macroinvertebrates and zooplankton) of glacier retreat in these environments. To assess parallels in biotic responses across streams and lakes, both primary data and findings from other publications were synthesised. Using TITAN (Threshold Indicator Taxa ANalysis) changes in community composition of river taxa were identified at thresholds of < 5.1% glacier cover and < 66.6% meltwater contribution. Below these thresholds the loss of cold stenothermic benthic invertebrate taxa, Diamesa spp. and the Pyrenean endemic Rhyacophila angelieri was apparent. Some generalist taxa including Protonemura sp., Perla grandis, Baetis alpinus, Rhithrogena loyolaea and Microspectra sp. increased when glacier cover was < 2.7% and < 52% meltwater. Patterns were not as distinct for the alpine lakes, due to fewer sampling sites; however, Daphnia longispina grp. and the benthic invertebrate groups Plectopera and Planaria were identified as potential indicator taxa. While further work is required to assess potential indicator taxa for alpine lake systems, findings from alpine river systems were consistent between methods for assessing glacier influence (meltwater contribution/glacier cover). Hence, it is clear that TITAN could become a useful management tool, enabling: (i) the identification of taxa particularly

  18. Solar wind stream interfaces

    International Nuclear Information System (INIS)

    Gosling, J.T.; Asbridge, J.R.; Bame, S.J.; Feldman, W.C.

    1978-01-01

    Measurements aboard Imp 6, 7, and 8 reveal that approximately one third of all high-speed solar wind streams observed at 1 AU contain a sharp boundary (of thickness less than approx.4 x 10 4 km) near their leading edge, called a stream interface, which separates plasma of distinctly different properties and origins. Identified as discontinuities across which the density drops abruptly, the proton temperature increases abruptly, and the speed rises, stream interfaces are remarkably similar in character from one stream to the next. A superposed epoch analysis of plasma data has been performed for 23 discontinuous stream interfaces observed during the interval March 1971 through August 1974. Among the results of this analysis are the following: (1) a stream interface separates what was originally thick (i.e., dense) slow gas from what was originally thin (i.e., rare) fast gas; (2) the interface is the site of a discontinuous shear in the solar wind flow in a frame of reference corotating with the sun; (3) stream interfaces occur at speeds less than 450 km s - 1 and close to or at the maximum of the pressure ridge at the leading edges of high-speed streams; (4) a discontinuous rise by approx.40% in electron temperature occurs at the interface; and (5) discontinuous changes (usually rises) in alpha particle abundance and flow speed relative to the protons occur at the interface. Stream interfaces do not generally recur on successive solar rotations, even though the streams in which they are embedded often do. At distances beyond several astronomical units, stream interfaces should be bounded by forward-reverse shock pairs; three of four reverse shocks observed at 1 AU during 1971--1974 were preceded within approx.1 day by stream interfaces. Our observations suggest that many streams close to the sun are bounded on all sides by large radial velocity shears separating rapidly expanding plasma from more slowly expanding plasma

  19. Sequence diversity and evolution of antimicrobial peptides in invertebrates.

    Science.gov (United States)

    Tassanakajon, Anchalee; Somboonwiwat, Kunlaya; Amparyup, Piti

    2015-02-01

    Antimicrobial peptides (AMPs) are evolutionarily ancient molecules that act as the key components in the invertebrate innate immunity against invading pathogens. Several AMPs have been identified and characterized in invertebrates, and found to display considerable diversity in their amino acid sequence, structure and biological activity. AMP genes appear to have rapidly evolved, which might have arisen from the co-evolutionary arms race between host and pathogens, and enabled organisms to survive in different microbial environments. Here, the sequence diversity of invertebrate AMPs (defensins, cecropins, crustins and anti-lipopolysaccharide factors) are presented to provide a better understanding of the evolution pattern of these peptides that play a major role in host defense mechanisms. Copyright © 2014 Elsevier Ltd. All rights reserved.

  20. Isolation of key retinoid signalling and metabolic modules in invertebrates

    Directory of Open Access Journals (Sweden)

    Ana André

    2014-05-01

    Full Text Available Retinoids are a class of molecules related to vitamin A (Retinol that are required for regulation of critical chordate ndocrine-mediated process, such as embryonic development, reproduction, and vision. To maintain such physiological process, chordates have a complex mechanism to regulate the spatial and temporal distribution of retinoids that includes metabolic and signalling modules. Initially, retinoid modules were seen as a chordate novelty. However, emerging biochemical and genomic evidences have challenged this view, clearly pointing to a more basal ancestry than previously thought. However, for the majority of non-chordate invertebrate lineages a clearly characterization of the main enzymatic/molecular players is still missing. Despite limited, the available evidence supports the presence of biologically active retinoid pathways in invertebrates. In order to enhance our insights on retinoid biology, evolution, and its putative disruption by environmental chemicals, the isolation and functional characterization of key retinoid metabolic players in marine invertebrates has been carried out.

  1. Protozoa interaction with aquatic invertebrate: interest for watercourses biomonitoring.

    Science.gov (United States)

    Palos Ladeiro, M; Bigot, A; Aubert, D; Hohweyer, J; Favennec, L; Villena, I; Geffard, A

    2013-02-01

    Toxoplasma gondii, Cryptosporidium parvum, and Giardia duodenalis are human waterborne protozoa. These worldwide parasites had been detected in various watercourses as recreational, surface, drinking, river, and seawater. As of today, water protozoa detection was based on large water filtration and on sample concentration. Another tool like aquatic invertebrate parasitism could be used for sanitary and environmental biomonitoring. In fact, organisms like filter feeders could already filtrate and concentrate protozoa directly in their tissues in proportion to ambient concentration. So molluscan shellfish can be used as a bioindicator of protozoa contamination level in a site since they were sedentary. Nevertheless, only a few researches had focused on nonspecific parasitism like protozoa infection on aquatic invertebrates. Objectives of this review are twofold: Firstly, an overview of protozoa in worldwide water was presented. Secondly, current knowledge of protozoa parasitism on aquatic invertebrates was detailed and the lack of data of their biological impact was pointed out.

  2. Meroterpenes from Marine Invertebrates: Structures, Occurrence, and Ecological Implications

    Science.gov (United States)

    Menna, Marialuisa; Imperatore, Concetta; D’Aniello, Filomena; Aiello, Anna

    2013-01-01

    Meroterpenes are widely distributed among marine organisms; they are particularly abundant within brown algae, but other important sources include microorganisms and invertebrates. In the present review the structures and bioactivities of meroterpenes from marine invertebrates, mainly sponges and tunicates, are summarized. More than 300 molecules, often complex and with unique skeletons originating from intra- and inter-molecular cyclizations, and/or rearrangements, are illustrated. The reported syntheses are mentioned. The issue of a potential microbial link to their biosynthesis is also shortly outlined. PMID:23685889

  3. Distribution pattern of benthic invertebrates in Danish estuaries

    DEFF Research Database (Denmark)

    Kristensen, Erik; Delefosse, Matthieu; Quintana, Cintia Organo

    2013-01-01

    distribution of 9 dominating benthic invertebrate species from two study areas, the estuaries Odense Fjord and Roskilde Fjord, Denmark. The slope (b) obtained fromthe power relationship of sample variance (s2) versusmean (μ) appears to be species-specific and independent of location and time. It ranges from...... factors such as behavior and intraspecific interactions. Thus, at the examined spatial scale, the more intense intraspecific interactions (e.g. territoriality) cause less aggregated distribution patterns among large- than small-bodied invertebrates. The species-specific interactions seem sufficiently...

  4. Copper hazards to fish, wildlife and invertebrates: a synoptic review

    Science.gov (United States)

    Eisler, Ronald

    1998-01-01

    Selective review and synthesis of the technical literature on copper and copper salts in the environment and their effects primarily on fishes, birds, mammals, terrestrial and aquatic invertebrates, and other natural resources. The subtopics include copper sources and uses; chemical and biochemical properties; concentrations of copper in field collections of abiotic materials and living organisms; effects of copper deficiency; lethal and sublethal effects on terrestrial plants and invertebrates, aquatic organisms, birds and mammals, including effects on survival, growth, reproduction, behavior, metabolism, carcinogenicity, matagenicity, and teratogenicity; proposed criteria for the protection of human health and sensitive natural resources; and recommendations for additional research.

  5. Ion-probe U–Pb dating of authigenic and detrital opal from Neogene-Quaternary alluvium

    Science.gov (United States)

    Neymark, Leonid; Paces, James B.

    2013-01-01

    Knowing depositional ages of alluvial fans is essential for many tectonic, paleoclimatic, and geomorphic studies in arid environments. The use of U–Pb dating on secondary silica to establish the age of Neogene-Quaternary clastic sediments was tested on samples of authigenic and detrital opal and chalcedony from depths of ∼25 to 53 m in boreholes at Midway Valley, Nevada. Dating of authigenic opal present as rinds on rock clasts and in calcite/silica cements establishes minimum ages of alluvium deposition; dating of detrital opal or chalcedony derived from the source volcanic rocks gives the maximum age of sediment deposition.Materials analyzed included 12 samples of authigenic opal, one sample of fracture-coating opal from bedrock, one sample of detrital opal, and two samples of detrital chalcedony. Uranium–lead isotope data were obtained by both thermal ionization mass spectrometry and ion-microprobe. Uranium concentrations ranged from tens to hundreds of μg/g. Relatively large U/Pb allowed calculation of 206Pb/238U ages that ranged from 1.64±0.36 (2σ) to 6.16±0.50 Ma for authigenic opal and from 8.34±0.28 to 11.2±1.3 Ma for detrital opal/chalcedony. Three samples with the most radiogenic Pb isotope compositions also allowed calculation of 207Pb/235U ages, which were concordant with 206Pb/238U ages from the same samples.These results indicate that basin development at Midway Valley was initiated between about 8 and 6 Ma, and that the basin was filled at long-term average deposition rates of less than 1 cm/ka. Because alluvium in Midway Valley was derived from adjacent highlands at Yucca Mountain, the low rates of deposition determined in this study may imply a slow rate of erosion of Yucca Mountain. Volcanic strata underlying the basin are offset by a number of buried faults to a greater degree than the relatively smooth-sloping bedrock/alluvium contact. These geologic relations indicate that movement on most faults ceased prior to erosional

  6. Inventory of miscellaneous streams

    International Nuclear Information System (INIS)

    Lueck, K.J.

    1995-09-01

    On December 23, 1991, the US Department of Energy, Richland Operations Office (RL) and the Washington State Department of Ecology (Ecology) agreed to adhere to the provisions of the Department of Ecology Consent Order. The Consent Order lists the regulatory milestones for liquid effluent streams at the Hanford Site to comply with the permitting requirements of Washington Administrative Code. The RL provided the US Congress a Plan and Schedule to discontinue disposal of contaminated liquid effluent into the soil column on the Hanford Site. The plan and schedule document contained a strategy for the implementation of alternative treatment and disposal systems. This strategy included prioritizing the streams into two phases. The Phase 1 streams were considered to be higher priority than the Phase 2 streams. The actions recommended for the Phase 1 and 2 streams in the two reports were incorporated in the Hanford Federal Facility Agreement and Consent Order. Miscellaneous Streams are those liquid effluents streams identified within the Consent Order that are discharged to the ground but are not categorized as Phase 1 or Phase 2 Streams. This document consists of an inventory of the liquid effluent streams being discharged into the Hanford soil column

  7. Hydrography - Streams and Shorelines

    Data.gov (United States)

    California Natural Resource Agency — The hydrography layer consists of flowing waters (rivers and streams), standing waters (lakes and ponds), and wetlands -- both natural and manmade. Two separate...

  8. Quality of streams in Johnson County, Kansas, 2002--10

    Science.gov (United States)

    Rasmussen, Teresa J.; Stone, Mandy S.; Poulton, Barry C.; Graham, Jennifer L.

    2012-01-01

    significantly negatively correlated with biological conditions. Specific conductance of water and sum of PAH concentrations in streambed sediment also were significantly negatively correlated with biological conditions. Total nitrogen in water and total phosphorus in streambed sediment were correlated with most of the invertebrate variables, which is a notable difference from previous analyses using smaller datasets, in which nutrient relations were weak or not detected. The most important habitat variables were sinuosity, length and continuity of natural buffers, riffle substrate embeddedness, and substrate cover diversity, each of which was correlated with all invertebrate metrics including a 10-metric combined score. Correlation analysis indicated that if riparian and in-stream habitat conditions improve then so might invertebrate communities and stream biological quality. Sixty-two percent of the variance in macroinvertebrate community metrics was explained by the single environmental factor, percent impervious surface. Invertebrate responses to urbanization in Johnson County indicated linearity rather than identifiable thresholds. Multiple linear regression models developed for each of the four macroinvertebrate metrics used to determine aquatic-life-support status indicated that percent impervious surface, as a measure of urban land use, explained 34 to 67 percent of the variability in biological communities. Results indicate that although multiple factors are correlated with stream quality degradation, general urbanization, as indicated by impervious surface area or urban land use, consistently is determined to be the fundamental factor causing change in stream quality. Effects of urbanization on Johnson County streams are similar to effects described in national studies that assess effects of urbanization on stream health. Individually important environmental factors such as specific conductance of water, PAHs in streambed sediment, and stream buffer conditions, are

  9. Urban development results in stressors that degrade stream ecosystems

    Science.gov (United States)

    Bell, Amanda H.; Coles, James F.; McMahon, Gerard; Woodside, Michael D.

    2012-01-01

    In 2003, eighty-three percent of Americans lived in metropolitan areas, and considerable population increases are predicted within the next 50 years. Nowhere are the environmental changes associated with urban development more evident than in urban streams. Contaminants, habitat destruction, and increasing streamflow flashiness resulting from urban development have been associated with the disruption of biological communities, particularly the loss of sensitive aquatic biota. Every stream is connected downstream to other water bodies, and inputs of contaminants and (or) sediments to streams can cause degradation downstream with adverse effects on biological communities and on economically valuable resources, such as fisheries and tourism. Understanding how algal, invertebrate, and fish communities respond to physical and chemical stressors associated with urban development can provide important clues on how multiple stressors may be managed to protect stream health as a watershed becomes increasingly urbanized. This fact sheet highlights selected findings of a comprehensive assessment by the National Water-Quality Assessment Program of the U.S. Geological Survey (USGS) of the effects of urban development on stream ecosystems in nine metropolitan study areas.

  10. Novel insights linking ecological health to biogeochemical hotspots in mixed land use stream systems

    DEFF Research Database (Denmark)

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

    Increasing modifications in land use and water management have resulted in multiple stressors impacting freshwater ecosystems globally. Chemicals with the potential to impact aquatic habitats are still often evaluated individually for their adverse effects on ecosystem health. This may lead...... pollution sources included two contaminated sites (factory, landfill), aquaculture, wastewater/industrial discharges, and diffuse sources from agriculture and urban areas (Sonne et al., 2017). Ecological status was determined by monitoring meiobenthic and macrobenthic invertebrate communities. The stream...

  11. SHRIMP U-Pb dating of detrital zircons in metamorphic rocks from northern Kyushu, western Japan

    International Nuclear Information System (INIS)

    Tsutsumi, Yukiyasu; Yokoyama, Kazumi; Terada, Kentaro; Sano, Yuji

    2003-01-01

    Radiometric ages of detrital zircons in psammitic schists from the Nagasaki, Kurume, Konoha and Kiyama areas, northern Kyushu, were obtained from 238 U/ 206 Pb ratio and isotopic compositions of Pb using a Sensitive High Resolution Ion Microprobe (SHRIMP II). Zircons from the Nagasaki, Kurume and Konoha areas show bimodal age distribution with peaks at ca. 1900 Ma and 250 Ma. It is suggested from this study that the older zircons were derived from Proterozoic landmass and the Korean Peninsula. Zircons from the Kiyama metamorphic rock show a different pattern with ages concentrated at 380-590 Ma. Such zircons are rare in rock samples from the Nagasaki, Kurume and Konoha areas, indicating that Kiyama rocks and a different origin than those from the other three areas. The youngest zircons from the Kiyama, Nagasaki, Kurume and Konoha areas show ages of 382±23 Ma, 238±13 Ma, 249±13 Ma, and 175±4 Ma, respectively, These data mark the upper age limit of their deposition. Since a continuous igneous activity occurred during the period from 300 to 170 Ma in Far East Asia, and the metamorphic age has been close to the zircon age of each area, these youngest ages for the Nagasaki, Kurume and Konoha areas are considered nearly contemporary to the depositional ages. An evaluation of the nature of metamorphism and available ages suggest the possibility that the Nagasaki metamorphic rocks as well as the schist from the Kurume area belong to the Suo zone of the Sangun belt, whereas the metamorphic rocks in the Konoha area may belong to the Ryoke belt or Suo zone of the Sangun belt. (author)

  12. Detrital phosphorus as a proxy of flooding events in the Changjiang River Basin

    Energy Technology Data Exchange (ETDEWEB)

    Meng, Jia [Key Laboratory of Marine Chemistry Theory and Technology, Ministry of Education, Qingdao 266100 (China); College of Chemistry and Chemical Engineering, Ocean University of China, Qingdao 266100 (China); Yao, Peng, E-mail: yaopeng@mail.ouc.edu.cn [Key Laboratory of Marine Chemistry Theory and Technology, Ministry of Education, Qingdao 266100 (China); Qingdao Collaborative Innovation Center of Marine Science and Technology, Qingdao 266100 (China); Institute of Marine Organic Geochemistry, Ocean University of China, Qingdao 266100 (China); Bianchi, Thomas S. [Department of Geological Sciences, University of Florida, Gainesville, FL 32611-2120 (United States); Li, Dong; Zhao, Bin; Xu, Bochao [Key Laboratory of Marine Chemistry Theory and Technology, Ministry of Education, Qingdao 266100 (China); College of Chemistry and Chemical Engineering, Ocean University of China, Qingdao 266100 (China); Yu, Zhigang [Key Laboratory of Marine Chemistry Theory and Technology, Ministry of Education, Qingdao 266100 (China); Institute of Marine Organic Geochemistry, Ocean University of China, Qingdao 266100 (China)

    2015-06-01

    In this study, sediment grain size (MGS), specific surface area (SSA), total organic carbon (TOC) contents, C/N molar ratios, stable carbon isotope, and P species in a sediment core, collected from the East China Sea (ECS) inner-shelf were measured to explore the applicability of detrital phosphorus (De-P) as a potential indicator of past flooding events in the Changjiang River Basin (CRB). In particular, we examined the linkages between the evolution of floods with regional climate changes and anthropogenic activities in the CRB. Peaks of De-P concentrations in sediments corresponded well with the worst flooding events of the CRB over the past two centuries (e.g., 1850s, 1860s, 1900s, 1920s, 1950s, 1980s, and 2000s). Moreover, De-P also corresponded well with the extreme hypoxic events in 1981 and 1998 in the Changjiang Estuary as indicated by Mo/Al ratios, indicating potential linkages between De-P as a flooding proxy to flood-induced hypoxia events in this region. In addition, a robust relationship was found among De-P, the floods in 1950s, 1980s, and 2000s of the CRB, the intensive El Niño-Southern Oscillation (ENSO), the abnormally weak East Asian Summer Monsoon (EASM) and the warm phase of Pacific Decadal Oscillation (PDO), suggesting that De-P also provided insights to linkages between regional climate change and flooding events in this region. - Highlights: • De-P was used to track past floods in the Changjiang River Basin (CRB). • De-P may serve as a proxy for flood-induced hypoxia events in the Changjiang Estuary. • De-P may be a proxy for examining linkages between floods and climatic drivers.

  13. Detrital phosphorus as a proxy of flooding events in the Changjiang River Basin

    International Nuclear Information System (INIS)

    Meng, Jia; Yao, Peng; Bianchi, Thomas S.; Li, Dong; Zhao, Bin; Xu, Bochao; Yu, Zhigang

    2015-01-01

    In this study, sediment grain size (MGS), specific surface area (SSA), total organic carbon (TOC) contents, C/N molar ratios, stable carbon isotope, and P species in a sediment core, collected from the East China Sea (ECS) inner-shelf were measured to explore the applicability of detrital phosphorus (De-P) as a potential indicator of past flooding events in the Changjiang River Basin (CRB). In particular, we examined the linkages between the evolution of floods with regional climate changes and anthropogenic activities in the CRB. Peaks of De-P concentrations in sediments corresponded well with the worst flooding events of the CRB over the past two centuries (e.g., 1850s, 1860s, 1900s, 1920s, 1950s, 1980s, and 2000s). Moreover, De-P also corresponded well with the extreme hypoxic events in 1981 and 1998 in the Changjiang Estuary as indicated by Mo/Al ratios, indicating potential linkages between De-P as a flooding proxy to flood-induced hypoxia events in this region. In addition, a robust relationship was found among De-P, the floods in 1950s, 1980s, and 2000s of the CRB, the intensive El Niño-Southern Oscillation (ENSO), the abnormally weak East Asian Summer Monsoon (EASM) and the warm phase of Pacific Decadal Oscillation (PDO), suggesting that De-P also provided insights to linkages between regional climate change and flooding events in this region. - Highlights: • De-P was used to track past floods in the Changjiang River Basin (CRB). • De-P may serve as a proxy for flood-induced hypoxia events in the Changjiang Estuary. • De-P may be a proxy for examining linkages between floods and climatic drivers

  14. Detrital shadows: estuarine food web connectivity depends on fluvial influence and consumer feeding mode.

    Science.gov (United States)

    Howe, Emily; Simenstad, Charles A; Ogston, Andrea

    2017-10-01

    We measured the influence of landscape setting on estuarine food web connectivity in five macrotidal Pacific Northwest estuaries across a gradient of freshwater influence. We used stable isotopes (δ 13 C, δ 15 N, δ 34 S) in combination with a Bayesian mixing model to trace primary producer contributions to suspension- and deposit-feeding bivalve consumers (Mytilus trossulus and Macoma nasuta) transplanted into three estuarine vegetation zones: emergent marsh, mudflat, and eelgrass. Eelgrass includes both Japanese eelgrass (Zostera japonica) and native eelgrass (Zostera marina). Fluvial discharge and consumer feeding mode strongly influenced the strength and spatial scale of observed food web linkages, while season played a secondary role. Mussels displayed strong cross-ecosystem connectivity in all estuaries, with decreasing marine influence in the more fluvial estuaries. Mussel diets indicated homogenization of detrital sources within the water column of each estuary. In contrast, the diets of benthic deposit-feeding clams indicated stronger compartmentalization in food web connectivity, especially in the largest river delta where clam diets were trophically disconnected from marsh sources of detritus. This suggests detritus deposition is patchy across space, and less homogenous than the suspended detritus pool. In addition to fluvial setting, other estuary-specific environmental drivers, such as marsh area or particle transport speed, influenced the degree of food web linkages across space and time, often accounting for unexpected patterns in food web connectivity. Transformations of the estuarine landscape that alter river hydrology or availability of detritus sources can thus potentially disrupt natural food web connectivity at the landscape scale, especially for sedentary organisms, which cannot track their food sources through space. © 2017 by the Ecological Society of America.

  15. Thinking beyond the Bioreactor Box: Incorporating Stream Ecology into Edge-of-Field Nitrate Management.

    Science.gov (United States)

    Goeller, Brandon C; Febria, Catherine M; Harding, Jon S; McIntosh, Angus R

    2016-05-01

    Around the world, artificially drained agricultural lands are significant sources of reactive nitrogen to stream ecosystems, creating substantial stream health problems. One management strategy is the deployment of denitrification enhancement tools. Here, we evaluate the factors affecting the potential of denitrifying bioreactors to improve stream health and ecosystem services. The performance of bioreactors and the structure and functioning of stream biotic communities are linked by environmental parameters like dissolved oxygen and nitrate-nitrogen concentrations, dissolved organic carbon availability, flow and temperature regimes, and fine sediment accumulations. However, evidence of bioreactors' ability to improve waterway health and ecosystem services is lacking. To improve the potential of bioreactors to enhance desirable stream ecosystem functioning, future assessments of field-scale bioreactors should evaluate the influences of bioreactor performance on ecological indicators such as primary production, organic matter processing, stream metabolism, and invertebrate and fish assemblage structure and function. These stream health impact assessments should be conducted at ecologically relevant spatial and temporal scales. Bioreactors have great potential to make significant contributions to improving water quality, stream health, and ecosystem services if they are tailored to site-specific conditions and implemented strategically with land-based and stream-based mitigation tools within watersheds. This will involve combining economic, logistical, and ecological information in their implementation. Copyright © by the American Society of Agronomy, Crop Science Society of America, and Soil Science Society of America, Inc.

  16. Invertebrate neurophylogeny: suggested terms and definitions for a neuroanatomical glossary

    Directory of Open Access Journals (Sweden)

    Müller Carsten HG

    2010-11-01

    Full Text Available Abstract Background Invertebrate nervous systems are highly disparate between different taxa. This is reflected in the terminology used to describe them, which is very rich and often confusing. Even very general terms such as 'brain', 'nerve', and 'eye' have been used in various ways in the different animal groups, but no consensus on the exact meaning exists. This impedes our understanding of the architecture of the invertebrate nervous system in general and of evolutionary transformations of nervous system characters between different taxa. Results We provide a glossary of invertebrate neuroanatomical terms with a precise and consistent terminology, taxon-independent and free of homology assumptions. This terminology is intended to form a basis for new morphological descriptions. A total of 47 terms are defined. Each entry consists of a definition, discouraged terms, and a background/comment section. Conclusions The use of our revised neuroanatomical terminology in any new descriptions of the anatomy of invertebrate nervous systems will improve the comparability of this organ system and its substructures between the various taxa, and finally even lead to better and more robust homology hypotheses.

  17. Marine invertebrate diversity in Aristotle’s zoology

    NARCIS (Netherlands)

    Voultsiadou, E.; Vafidis, D.

    2007-01-01

    The aim of this paper is to bring to light Aristotle’s knowledge of marine invertebrate diversity as this has been recorded in his works 25 centuries ago, and set it against current knowledge. The analysis of information derived from a thorough study of his zoological writings revealed 866 records

  18. Some unsolved problems concerning copepods associated with marine invertebrates

    NARCIS (Netherlands)

    Gotto, R.V.

    1990-01-01

    Three unsolved problems relating to symbiotic copepods of marine invertebrates are discussed: 1. The whereabouts of the unknown male of the gill parasite of lobsters, Nicothoe astaci. 2. The occurrence of very large and apparently post-reproductive females in the annelidicolous Cyclorhiza megalova.

  19. Trophic transfer of pyrene metabolites between aquatic invertebrates

    International Nuclear Information System (INIS)

    Carrasco Navarro, V.; Leppänen, M.T.; Kukkonen, J.V.K.; Godoy Olmos, S.

    2013-01-01

    The trophic transfer of pyrene metabolites was studied using Gammarus setosus as a predator and the invertebrates Lumbriculus variegatus and Chironomus riparius as prey. The results obtained by liquid scintillation counting confirmed that the pyrene metabolites produced by the aquatic invertebrates L. variegatus and C. riparius were transferred to G. setosus through the diet. More detailed analyses by liquid chromatography discovered that two of the metabolites produced by C. riparius appeared in the chromatograms of G. setosus tissue extracts, proving their trophic transfer. These metabolites were not present in chromatograms of G. setosus exclusively exposed to pyrene. The present study supports the trophic transfer of PAH metabolites between benthic macroinvertebrates and common species of an arctic amphipod. As some PAH metabolites are more toxic than the parent compounds, the present study raises concerns about the consequences of their trophic transfer and the fate and effects of PAHs in natural environments. - Highlights: ► The trophic transfer of pyrene metabolites between invertebrates was evaluated. ► Biotransformation of pyrene by L. variegatus and C. riparius is different. ► Metabolites produced by L. variegatus and C. riparius are transferred to G. setosus. ► Specifically, two metabolites produced by C. riparius were transferred. - Some of the pyrene metabolites produced by the model invertebrates L. variegatus and C. riparius are transferred to G. setosus through the diet, proving their trophic transfer.

  20. Nitrous oxide production associated with coastal marine invertebrates

    DEFF Research Database (Denmark)

    Heisterkamp, Ines Maria; Schramm, Andreas; de Beer, Dirk

    2010-01-01

    Several freshwater and terrestrial invertebrate species emit the greenhouse gas nitrous oxide (N2O). The N2O production associated with these animals was ascribed to incomplete denitrification by ingested sediment or soil bacteria. The present study shows that many marine invertebrates also emit N2......O at substantial rates. A total of 19 invertebrate species collected in the German Wadden Sea and in Aarhus Bay, Denmark, and 1 aquacultured shrimp species were tested for N2O emission. Potential N2O emission rates ranged from 0 to 1.354 nmol ind.–1 h–1, with an average rate of 0.320 nmol ind.–1 h–1...... with an experimentally cleaned shell. Thus, the N2O production associated with marine invertebrates is apparently not due to gut denitrification in every species, but may also result from microbial activity on the external surfaces of animals. The high abundance and potential N2O emission rates of many marine...

  1. Bibliography of African inland water invertebrates (to 1980)

    CSIR Research Space (South Africa)

    Davies, BR

    1982-09-01

    Full Text Available This bibliography is a direct outcome of the SIL-UNEP Workshop on African Limnology held at the University of Nairobi, Kenya, between 16-23 December, 1979. Part 1 of the framework document for the A4 section of the Workshop - "Invertebrates...

  2. Invertebrates: Revealing a Hidden World in the Year of Biodiversity

    Science.gov (United States)

    Sanders, Dawn

    2010-01-01

    Biodiversity means the variety of life in all its forms. It includes the variety of species and ecosystems in the world, and genetic variation. Invertebrates are one of the largest and most accessible groups of animals for primary children to study. In this article, the author explains why and how children should engage with the idea of…

  3. Effects of environmental stressors on lipid metabolism in aquatic invertebrates.

    Science.gov (United States)

    Lee, Min-Chul; Park, Jun Chul; Lee, Jae-Seong

    2018-07-01

    Lipid metabolism is crucial for the survival and propagation of the species, since lipids are an essential cellular component across animal taxa for maintaining homeostasis in the presence of environmental stressors. This review aims to summarize information on the lipid metabolism under environmental stressors in aquatic invertebrates. Fatty acid synthesis from glucose via de novo lipogenesis (DNL) pathway is mostly well-conserved across animal taxa. The structure of free fatty acid (FFA) from both dietary and DNL pathway could be transformed by elongase and desaturase. In addition, FFA can be stored in lipid droplet as triacylglycerol, upon attachment to glycerol. However, due to the limited information on both gene and lipid composition, in-depth studies on the structural modification of FFA and their storage conformation are required. Despite previously validated evidences on the disturbance of the normal life cycle and lipid homeostasis by the environmental stressors (e.g., obesogens, salinity, temperature, pCO 2 , and nutrients) in the aquatic invertebrates, the mechanism behind these effects are still poorly understood. To overcome this limitation, omics approaches such as transcriptomic and proteomic analyses have been used, but there are still gaps in our knowledge on aquatic invertebrates as well as the lipidome. This paper provides a deeper understanding of lipid metabolism in aquatic invertebrates. Copyright © 2018 Elsevier B.V. All rights reserved.

  4. The association between invertebrates and macrophytes in a ...

    African Journals Online (AJOL)

    The invertebrate fauna associated with aquatic macrophytes in the littoral of Lake Kariba was studied over a three-month period in 2002. Animals from seven classes — Hirudinea, Oligochaeta, Turbellaria, Insecta, Crustacea, Bivalvia and Gastropoda — were collected. Two hirudineans, Placobdella sp. and Haemopsis sp., ...

  5. Advancing Neuroscience Research in Africa: Invertebrate Species to the Rescue.

    Science.gov (United States)

    Balogun, Wasiu Gbolahan; Cobham, Ansa Emmanuel; Amin, Abdulbasit; Seeni, Azman

    2018-03-15

    Neuroscience research and training in many African countries are difficult due to funding and infrastructure deficit. This has resulted in few neuroscientists within Africa. However, invertebrates such as Drosophila and Caenorhabditis elegans could provide the perfect answer to these difficulties. These organisms are cheap, easy to handle and offer a comparable advantage over vertebrates in neuroscience research modeling because they have a simple nervous system and exhibit well-defined behaviors. Studies using invertebrates have helped to understand neurosciences and the complexes associated with it. If Africa wants to catch up with the rest of the world in neuroscience research, it needs to employ this innovative cost-effective approach in its research. To improve invertebrate neuroscience within the Africa continent, the authors advocated the establishment of invertebrate research centers either at regional or national level across Africa. Finally, there is also a need to provide public funding to consolidate the gains that have been made by not-for-profit international organizations over the years. Copyright © 2018 IBRO. Published by Elsevier Ltd. All rights reserved.

  6. Freshwater invertebrates of sub-Antarctic Marion Island | Dartnall ...

    African Journals Online (AJOL)

    The aquatic species include five platyhelminthes, a gastrotrich, three tardigrades, 28 rotifers, six nematodes, two annelids and 11 arthropods. Most are familiar species that have been recorded on other sub-Antarctic islands. The invertebrate faunas of the various freshwater habitats were basically similar in species ...

  7. Effect of burn area on invertebrate recolonization in grasslands in ...

    African Journals Online (AJOL)

    Our study examined the short-term response of grassland invertebrate communities to fire in the South African Drakensberg, in relation to distance from the edge of a burn. We aimed to establish which species survive fire and the dynamics of the post-fire recolonization process, and thereby contribute to establishing the ...

  8. Biodiversity and abundance of fish and macrobenthic invertebrates ...

    African Journals Online (AJOL)

    A study of the occurrence and distribution offish and macrobenthic invertebrates of Nguru Lake was conducted between May, 2006 and April, 2007. Thirteen families of fish consisting of 24 species where discovered. The fishes were dominate.d by the family Cichlidae (64.44%). An average of 540. 1 7kg of fish was caught ...

  9. LHCb trigger streams optimization

    Science.gov (United States)

    Derkach, D.; Kazeev, N.; Neychev, R.; Panin, A.; Trofimov, I.; Ustyuzhanin, A.; Vesterinen, M.

    2017-10-01

    The LHCb experiment stores around 1011 collision events per year. A typical physics analysis deals with a final sample of up to 107 events. Event preselection algorithms (lines) are used for data reduction. Since the data are stored in a format that requires sequential access, the lines are grouped into several output file streams, in order to increase the efficiency of user analysis jobs that read these data. The scheme efficiency heavily depends on the stream composition. By putting similar lines together and balancing the stream sizes it is possible to reduce the overhead. We present a method for finding an optimal stream composition. The method is applied to a part of the LHCb data (Turbo stream) on the stage where it is prepared for user physics analysis. This results in an expected improvement of 15% in the speed of user analysis jobs, and will be applied on data to be recorded in 2017.

  10. Crawling to collapse: ecologically unsound ornamental invertebrate fisheries.

    Directory of Open Access Journals (Sweden)

    Andrew Rhyne

    Full Text Available BACKGROUND: Fishery management has historically been an inexact and reactionary discipline, often taking action only after a critical stock suffers overfishing or collapse. The invertebrate ornamental fishery in the State of Florida, with increasing catches over a more diverse array of species, is poised for collapse. Current management is static and the lack of an adaptive strategy will not allow for adequate responses associated with managing this multi-species fishery. The last decade has seen aquarium hobbyists shift their display preference from fish-only tanks to miniature reef ecosystems that include many invertebrate species, creating increased demand without proper oversight. The once small ornamental fishery has become an invertebrate-dominated major industry supplying five continents. METHODOLOGY/PRINCIPAL FINDINGS: Here, we analyzed the Florida Marine Life Fishery (FLML landing data from 1994 to 2007 for all invertebrate species. The data were organized to reflect both ecosystem purpose (in the wild and ecosystem services (commodities for each reported species to address the following question: Are ornamental invertebrates being exploited for their fundamental ecosystem services and economic value at the expense of reef resilience? We found that 9 million individuals were collected in 2007, 6 million of which were grazers. CONCLUSIONS/SIGNIFICANCE: The number of grazers now exceeds, by two-fold, the number of specimens collected for curio and ornamental purposes altogether, representing a major categorical shift. In general, landings have increased 10-fold since 1994, though the number of licenses has been dramatically reduced. Thus, despite current management strategies, the FLML Fishery appears to be crawling to collapse.

  11. The overlooked biodiversity of flower-visiting invertebrates.

    Directory of Open Access Journals (Sweden)

    Carl W Wardhaugh

    Full Text Available Estimates suggest that perhaps 40% of all invertebrate species are found in tropical rainforest canopies. Extrapolations of total diversity and food web analyses have been based almost exclusively on species inhabiting the foliage, under the assumption that foliage samples are representative of the entire canopy. We examined the validity of this assumption by comparing the density of invertebrates and the species richness of beetles across three canopy microhabitats (mature leaves, new leaves and flowers on a one hectare plot in an Australian tropical rainforest. Specifically, we tested two hypotheses: 1 canopy invertebrate density and species richness are directly proportional to the amount of resource available; and 2 canopy microhabitats represent discrete resources that are utilised by their own specialised invertebrate communities. We show that flowers in the canopy support invertebrate densities that are ten to ten thousand times greater than on the nearby foliage when expressed on a per-unit resource biomass basis. Furthermore, species-level analyses of the beetle fauna revealed that flowers support a unique and remarkably rich fauna compared to foliage, with very little species overlap between microhabitats. We reject the hypothesis that the insect fauna on mature foliage is representative of the greater canopy community even though mature foliage comprises a very large proportion of canopy plant biomass. Although the significance of the evolutionary relationship between flowers and insects is well known with respect to plant reproduction, less is known about the importance of flowers as resources for tropical insects. Consequently, we suggest that this constitutes a more important piece of the 'diversity jigsaw puzzle' than has been previously recognised and could alter our understanding of the evolution of plant-herbivore interactions and food web dynamics, and provide a better foundation for accurately estimating global species

  12. Geomorphology controls the trophic base of stream food webs in a boreal watershed .

    Science.gov (United States)

    Smits, Adrianne P; Schindler, Daniel E; Brett, Michael T

    2015-07-01

    Abstract. Physical attributes of rivers control the quantity and quality of energy sources available to consumers, but it remains untested whether geomorphic conditions of whole watersheds affect the assimilation of different resources by stream organisms. We compared the fatty acid (FA) compositions of two invertebrate taxa (caddisflies, mayflies) collected from 16 streams in southwest Alaska, USA, to assess how assimilation of terrestrial organic matter (OM) and algae varied across a landscape gradient in watershed features. We found relatively higher assimilation of algae in high-gradient streams compared with low-gradient streams, and the opposite pattern for assimilation of terrestrial OM and microbes. The strength of these patterns was more pronounced for caddisflies than mayflies. Invertebrates from low-gradient watersheds had FA markers unique to methane-oxidizing bacteria and sulfate-reducing microbes, indicating a contribution of anaerobic pathways to primary consumers. Diversity of FA composition was highest in watersheds of intermediate slopes that contain both significant terrestrial inputs as well as high algal biomass. By controlling the accumulation rate and processing of terrestrial OM, watershed features influence the energetic base of food webs in boreal streams.

  13. Asteroid/meteorite streams

    Science.gov (United States)

    Drummond, J.

    The independent discovery of the same three streams (named alpha, beta, and gamma) among 139 Earth approaching asteroids and among 89 meteorite producing fireballs presents the possibility of matching specific meteorites to specific asteroids, or at least to asteroids in the same stream and, therefore, presumably of the same composition. Although perhaps of limited practical value, the three meteorites with known orbits are all ordinary chondrites. To identify, in general, the taxonomic type of the parent asteroid, however, would be of great scientific interest since these most abundant meteorite types cannot be unambiguously spectrally matched to an asteroid type. The H5 Pribram meteorite and asteroid 4486 (unclassified) are not part of a stream, but travel in fairly similar orbits. The LL5 Innisfree meteorite is orbitally similar to asteroid 1989DA (unclassified), and both are members of a fourth stream (delta) defined by five meteorite-dropping fireballs and this one asteroid. The H5 Lost City meteorite is orbitally similar to 1980AA (S type), which is a member of stream gamma defined by four asteroids and four fireballs. Another asteroid in this stream is classified as an S type, another is QU, and the fourth is unclassified. This stream suggests that ordinary chondrites should be associated with S (and/or Q) asteroids. Two of the known four V type asteroids belong to another stream, beta, defined by five asteroids and four meteorite-dropping (but unrecovered) fireballs, making it the most probable source of the eucrites. The final stream, alpha, defined by five asteroids and three fireballs is of unknown composition since no meteorites have been recovered and only one asteroid has an ambiguous classification of QRS. If this stream, or any other as yet undiscovered ones, were found to be composed of a more practical material (e.g., water or metalrich), then recovery of the associated meteorites would provide an opportunity for in-hand analysis of a potential

  14. Evaluation of Metal Toxicity in Streams Affected by Abandoned Mine Lands, Upper Animas River Watershed, Colorado

    Science.gov (United States)

    Besser, John M.; Allert, Ann L.; Hardesty, Douglas K.; Ingersoll, Christopher G.; May, Thomas W.; Wang, Ning; Leib, Kenneth J.

    2001-01-01

    Acid drainage from abandoned mines and from naturally-acidic rocks and soil in the upper Animas River watershed of Colorado generates elevated concentrations of acidity and dissolved metals in stream waters and deposition of metal-contaminated particulates in streambed sediments, resulting in both toxicity and habitat degradation for stream biota. High concentrations of iron (Fe), aluminum (Al), zinc (Zn), copper (Cu), cadmium (Cd), and lead (Pb) occur in acid streams draining headwaters of the upper Animas River watershed, and high concentrations of some metals, especially Zn, persist in circumneutral reaches of the Animas River and Mineral Creek, downstream of mixing zones of acid tributaries. Seasonal variation of metal concentrations is reflected in variation in toxicity of stream water. Loadings of dissolved metals to the upper Animas River and tributaries are greatest during summer, during periods of high stream discharge from snowmelt and monsoonal rains, but adverse effects on stream biota may be greater during winter low-flow periods, when stream flows are dominated by inputs of groundwater and contain greatest concentrations of dissolved metals. Fine stream-bed sediments of the upper Animas River watershed also contain elevated concentrations of potentially toxic metals. Greatest sediment metal concentrations occur in the Animas River upstream from Silverton, where there are extensive deposits of mine and mill tailings, and in mixing zones in the Animas River and lower Mineral Creek, where precipitates of Fe and Al oxides also contain high concentrations of other metals. This report summarizes the findings of a series of toxicity studies in streams of the upper Animas River watershed, conducted on-site and in the laboratory between 1998 and 2000. The objectives of these studies were: (1) to determine the relative toxicity of stream water and fine stream-bed sediments to fish and invertebrates; (2) to determine the seasonal range of toxicity in stream

  15. Percent Forest Adjacent to Streams

    Data.gov (United States)

    U.S. Environmental Protection Agency — The type of vegetation along a stream influences the water quality in the stream. Intact buffer strips of natural vegetation along streams tend to intercept...

  16. Percent Agriculture Adjacent to Streams

    Data.gov (United States)

    U.S. Environmental Protection Agency — The type of vegetation along a stream influences the water quality in the stream. Intact buffer strips of natural vegetation along streams tend to intercept...

  17. Detrital zircon provenance of the Hartselle Sandstone Unit, Southeastern USA: Insights into sediment source, paleogeography, and setting

    Science.gov (United States)

    Harthy, M. A.; Gifford, J.

    2017-12-01

    The Hartselle sandstone is an excellent example of an Oil sand, a resource rich in bitumen. The unit is a light-colored thick-bedded to massive quartzose sandstone, that is widespread across an area from Georgia in the east to Mississippi in the west, and south from Alabama to Kentucky as a northern border. Formation thickness ranges from 0 to more than 150 feet. The unit has been stratigraphically dated to the Middle-Upper Mississippian age. One hypothesis suggests that the sandstone unit formed from the geological remains of barrier islands located in the ocean between Gondwana and Laurentia. The Hartselle is thought to have formed by the movement waves and currents along the shoreline, which carried sand and concentrated it into a set of northwest to southeast trending barrier islands. Transgression-regression events shifted the islands back and forth in relation to the position of the shoreline, leading to the large areal extent of the unit. However, the current data are not enough to explain the geographical position of the Hartselle sandstone unit as it is not running parallel to the ancient shoreline. Another mystery is the source of the sand, some believing the source was from the south (Gondwana) and others that erosion was from the north (Laurentia). Detrital zircon provenance analysis will address the uncertainty in sediment source. We will compare zircon U-Pb age spectra to possible Laurentian and Gondwanan source areas to discriminate between these possibilities. In addition, the age of the youngest detrital zircon population will provide additional constraints on the maximum age of deposition for the unit. These detrital ages will also help us to understand the tectonic setting at the time of Hartselle deposition. Lastly, we aim to explain the widespread nature of the unit and the processes involved in the formation of the Hartselle sandstone. When taken together, these interpretations will illuminate the age, depositional and tectonic setting of a

  18. Extracting information on the spatial variability in erosion rate stored in detrital cooling age distributions in river sands

    Science.gov (United States)

    Braun, Jean; Gemignani, Lorenzo; van der Beek, Peter

    2018-03-01

    One of the main purposes of detrital thermochronology is to provide constraints on the regional-scale exhumation rate and its spatial variability in actively eroding mountain ranges. Procedures that use cooling age distributions coupled with hypsometry and thermal models have been developed in order to extract quantitative estimates of erosion rate and its spatial distribution, assuming steady state between tectonic uplift and erosion. This hypothesis precludes the use of these procedures to assess the likely transient response of mountain belts to changes in tectonic or climatic forcing. Other methods are based on an a priori knowledge of the in situ distribution of ages to interpret the detrital age distributions. In this paper, we describe a simple method that, using the observed detrital mineral age distributions collected along a river, allows us to extract information about the relative distribution of erosion rates in an eroding catchment without relying on a steady-state assumption, the value of thermal parameters or an a priori knowledge of in situ age distributions. The model is based on a relatively low number of parameters describing lithological variability among the various sub-catchments and their sizes and only uses the raw ages. The method we propose is tested against synthetic age distributions to demonstrate its accuracy and the optimum conditions for it use. In order to illustrate the method, we invert age distributions collected along the main trunk of the Tsangpo-Siang-Brahmaputra river system in the eastern Himalaya. From the inversion of the cooling age distributions we predict present-day erosion rates of the catchments along the Tsangpo-Siang-Brahmaputra river system, as well as some of its tributaries. We show that detrital age distributions contain dual information about present-day erosion rate, i.e., from the predicted distribution of surface ages within each catchment and from the relative contribution of any given catchment to the

  19. Extracting information on the spatial variability in erosion rate stored in detrital cooling age distributions in river sands

    Directory of Open Access Journals (Sweden)

    J. Braun

    2018-03-01

    Full Text Available One of the main purposes of detrital thermochronology is to provide constraints on the regional-scale exhumation rate and its spatial variability in actively eroding mountain ranges. Procedures that use cooling age distributions coupled with hypsometry and thermal models have been developed in order to extract quantitative estimates of erosion rate and its spatial distribution, assuming steady state between tectonic uplift and erosion. This hypothesis precludes the use of these procedures to assess the likely transient response of mountain belts to changes in tectonic or climatic forcing. Other methods are based on an a priori knowledge of the in situ distribution of ages to interpret the detrital age distributions. In this paper, we describe a simple method that, using the observed detrital mineral age distributions collected along a river, allows us to extract information about the relative distribution of erosion rates in an eroding catchment without relying on a steady-state assumption, the value of thermal parameters or an a priori knowledge of in situ age distributions. The model is based on a relatively low number of parameters describing lithological variability among the various sub-catchments and their sizes and only uses the raw ages. The method we propose is tested against synthetic age distributions to demonstrate its accuracy and the optimum conditions for it use. In order to illustrate the method, we invert age distributions collected along the main trunk of the Tsangpo–Siang–Brahmaputra river system in the eastern Himalaya. From the inversion of the cooling age distributions we predict present-day erosion rates of the catchments along the Tsangpo–Siang–Brahmaputra river system, as well as some of its tributaries. We show that detrital age distributions contain dual information about present-day erosion rate, i.e., from the predicted distribution of surface ages within each catchment and from the relative contribution of

  20. The Origin of the Chinese Central Tianshan Block in the Southern Central Asian Orogenic Belt: Evidence from Detrital Zircon Study

    Science.gov (United States)

    Huang, Z.; Long, X.; Yuan, C.

    2016-12-01

    The Chinese Central Tianshan Block (CTB) is one of the oldest continental fragments in the southern Central Asian Orogenic Belt (CAOB). Although it is vital for understanding the evolution of the CAOB, its origin has been poorly studied. The CTB was previously suggested to have been originated from the North China, the South China, the Tarim cratons or the East European Craton (Baltica). A total of 165 concordant U-Pb and Hf isotopic analyses of detrital zircon are obtained from three meta-sediments in the CTB, including one meta-sandstone from Xingxingxia formation and one meta-sandstone as well as one quartzite from Kawabulake formation. Detrital zircon grains from the Xingxingxia and Kawabulake formations are dominated by respective youngest age populations at 1002 Ma and 930-960 Ma, providing constraints on the maximum depositional ages for these two formations. Zircon grains from the meta-sediments have very similar age distributions, with two dominant peaks at 0.93-1.0 Ga and 1.0-1.6 Ga and a minor peak at 2.3-2.7 Ga. They have similar Hf isotopic signatures, suggesting that the meta-sediments in the CTB share similar sedimentary provenance. The early Neoproterozoic detrital zircon grains are mainly local-derived, whereas the Paleo-Mesoproterozoic grains are both autochthonous and allochthonous. The occurrence of these Mesoproterozoic and Neoproterozoic zircon grains are coincident with the Nuna breakup and the Rodinia assembly. This suggests that the CTB might experience the tectonic switching of the Nuna to the Rodinia. The distinct Meso-Neoproterozoic age patterns and Hf isotopic compositions of these detrital grains from the CTB and the surrounding blocks indicate that the CTB was not located close to the North China, the South China or the Tarim cratons in Precambrian. Our new data suggest that the CTB was most likely once a part of the East European Craton before the Neoproterozoic. This study was supported by National Basic Research Program of China

  1. The lower Mesozoic record of detrital zircon U-Pb geochronology of Sonora, Mexico, and its paleogeographic implications

    OpenAIRE

    González-León, Carlos M.; Valencia, Víctor A.; Lawton, Timothy F.; Amato, Jeffrey M.; Gehrels, George E.; Leggett, William J.; Montijo-Contreras, Óscar; Fernández, Miguel A.

    2009-01-01

    Detrital zircon U-Pb geochronology from each of the formations of the Triassic-Lower Jurassic Barranca and El Antimonio groups of central and northwestern Sonora and from the Lower Jurassic Basomari and Middle Jurassic Lily formations of northern Sonora indicate they contain distinctive zircon populations. A Proterozoic population has peak ages near 1.8, 1.7, 1.6, 1.4, and 1.1 Ga. A population of Permo-Triassic grains with important peak ages near 269, 254, 245, 234 and 227 Ma. A third popula...

  2. Detrital thermochronology of Rhine, Elbe and Meuse river sediment (Central Europe): implications for provenance, erosion and mineral fertility

    Science.gov (United States)

    Glotzbach, C.; Busschers, F. S.; Winsemann, J.

    2018-03-01

    Here we present detrital apatite fission track (AFT), zircon fission track (ZFT) and a few apatite (U-Th)/He (AHe) data of Middle Pleistocene to modern Rhine, Meuse and Elbe river sediments in order to resolve processes that control detrital age distributions (provenance, erosion and mineral fertility). We used a modelling approach to compare observed with theoretically predicted age distributions from an interpolated in situ AFT and ZFT age map. In situ cooling ages do show large differences in the Rhine drainage basin, facilitating the differentiation between different source regions. Inconsistencies between observed and theoretical age distributions of the Meuse and Elbe samples can be explained by mixing and reworking of sediments with different provenances (Meuse Middle Pleistocene terrace sediment) and a yet unexplored source region with old AFT ages (Elbe samples). Overall, the results show that detrital thermochronology is capable of identifying the provenance of Middle Pleistocene to modern sediments. The AFT age distributions of Rhine sediments are dominated ( 70%) by AFT ages representing the Alps. A possible explanation is higher erosion rates in the Alps as compared to areas outside the Alps. A Late Pleistocene sample from the Upper Rhine Graben contains apatite grains from the Molasse and Hegau volcanics, which we explain with a shift of the headwaters of the Rhine to the north as a result of intense Middle Pleistocene Riss glaciation. Contrary to the observed dominance of Alpine-derived AFT ages in Rhine sediments, the relative contribution of zircon ages with sources in the Alps is lower and significantly decreases downstream, suggesting a major source of zircons outside the Alps. This can be explained by increased zircon fertility of sediments derived from the Rhenish massif. Therefore, we conclude that erosion and mineral fertility are the main processes controlling detrital AFT and ZFT age distributions of the sampled river sediment. In case of

  3. Top-down control of invertebrates by Ninespine Stickleback in Arctic ponds

    Science.gov (United States)

    Laske, Sarah M.; Rosenberger, Amanda E.; Kane, William J.; Wipfli, Mark S.; Zimmerman, Christian E.

    2017-01-01

    Despite their widespread presence in northern-latitude ecosystems, the ecological role of Ninespine Stickleback Pungitius pungitius is not well understood. Ninespine Stickleback can occupy both top and intermediate trophic levels in freshwater ecosystems, so their role in food webs as a predator on invertebrates and as a forage fish for upper level consumers probably is substantial. We introduced Ninespine Sticklebacks to fishless ponds to elucidate their potential effects as a predator on invertebrate communities in Arctic lentic freshwaters. We hypothesized that Ninespine Stickleback would affect freshwater invertebrate communities in a top-down manner. We predicted that the addition of Ninespine Sticklebacks to fishless ponds would: 1) reduce invertebrate taxonomic richness, 2) decrease overall invertebrate abundance, 3) reduce invertebrate biomass, and 4) decrease average invertebrate body size. We tested our hypothesis at 2 locations by adding Ninespine Stickleback to isolated ponds and compared invertebrate communities over time between fish-addition and fishless control ponds. Ninespine Sticklebacks exerted strong top-down pressure on invertebrate communities mainly by changing invertebrate taxonomic richness and biomass and, to a lesser extent, abundance and average invertebrate size. Our results supported the hypothesis that Ninespine Stickleback may help shape lentic food webs in the Arctic.

  4. Wadeable Streams Assessment Data

    Science.gov (United States)

    The Wadeable Streams Assessment (WSA) is a first-ever statistically-valid survey of the biological condition of small streams throughout the U.S. The U.S. Environmental Protection Agency (EPA) worked with the states to conduct the assessment in 2004-2005. Data for each parameter sampled in the Wadeable Streams Assessment (WSA) are available for downloading in a series of files as comma separated values (*.csv). Each *.csv data file has a companion text file (*.txt) that lists a dataset label and individual descriptions for each variable. Users should view the *.txt files first to help guide their understanding and use of the data.

  5. Investigating the Early Carbon Cycle Using Carbonaceous Inclusions and Dissolved Carbon in Detrital Zircon

    Science.gov (United States)

    Bell, E. A.; Boehnke, P.; Harrison, M.; Mao, W. L.

    2015-12-01

    Because the terrestrial rock record extends only to ~4 Ga and older materials thus far identified are limited to detrital zircons, information about volatile abundances and cycles on early Earth is limited. Carbon, for instance, plays an important role not only in the modern biosphere but also in deep recycling of materials between the crust and mantle. We are investigating the record of carbon abundance and origin in Hadean zircons from Jack Hills (W. Australia) using two main approaches. First, carbon may partition into the zircon structure at trace levels during crystallization from a magma, and better understanding of this partitioning behavior will allow for zircon's use as a monitor of magmatic carbon contents. We have measured carbon abundances in zircon from a variety of igneous rocks (gabbro; I-, A-, and S-type granitoids) via SIMS and found that although abundances are typically low (average raw 12C/30Si ~ 1x10-6), S-type granite zircons can reach a factor of 1000 over this background. Around 10% of Hadean zircons investigated show similar enrichments, consistent with other evidence for the derivation of many Jack Hills zircons from S-type granitoids and with the establishment of modern-level carbon abundances in the crust by ca. 4.2 Ga. Diamond and graphite inclusions reported in the Jack Hills zircons by previous studies proved to be contamination by polishing debris, leaving the true abundance of these materials in the population uncertain. On a second front, we have identified and investigated primary carbonaceous inclusions in these zircons. From a population of over 10,000 Jack Hills zircons, we identified one concordant 4.10±0.01 Ga zircon that contains primary graphite inclusions (so interpreted due to their enclosure in a crack-free zircon host as shown by transmission X-ray microscopy and their crystal habit). Their δ13CPDB of -24±5‰ is consistent with a biogenic origin and, in the absence of a likely inorganic mechanism to produce such a

  6. 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.

  7. Future Roads Near Streams

    Data.gov (United States)

    U.S. Environmental Protection Agency — Roads are a source of auto related pollutants (e.g. gasoline, oil and other engine fluids). When roads are near streams, rain can wash these pollutants directly into...

  8. Channelized Streams in Iowa

    Data.gov (United States)

    Iowa State University GIS Support and Research Facility — This draft dataset consists of all ditches or channelized pieces of stream that could be identified using three input datasets; namely the1:24,000 National...

  9. Stochastic ice stream dynamics.

    Science.gov (United States)

    Mantelli, Elisa; Bertagni, Matteo Bernard; Ridolfi, Luca

    2016-08-09

    Ice streams are narrow corridors of fast-flowing ice that constitute the arterial drainage network of ice sheets. Therefore, changes in ice stream flow are key to understanding paleoclimate, sea level changes, and rapid disintegration of ice sheets during deglaciation. The dynamics of ice flow are tightly coupled to the climate system through atmospheric temperature and snow recharge, which are known exhibit stochastic variability. Here we focus on the interplay between stochastic climate forcing and ice stream temporal dynamics. Our work demonstrates that realistic climate fluctuations are able to (i) induce the coexistence of dynamic behaviors that would be incompatible in a purely deterministic system and (ii) drive ice stream flow away from the regime expected in a steady climate. We conclude that environmental noise appears to be crucial to interpreting the past behavior of ice sheets, as well as to predicting their future evolution.

  10. Roads Near Streams

    Data.gov (United States)

    U.S. Environmental Protection Agency — Roads are a source of auto related pollutants (e.g. gasoline, oil and other engine fluids). When roads are near streams, rain can wash these pollutants directly into...

  11. Streaming tearing mode

    Science.gov (United States)

    Shigeta, M.; Sato, T.; Dasgupta, B.

    1985-01-01

    The magnetohydrodynamic stability of streaming tearing mode is investigated numerically. A bulk plasma flow parallel to the antiparallel magnetic field lines and localized in the neutral sheet excites a streaming tearing mode more strongly than the usual tearing mode, particularly for the wavelength of the order of the neutral sheet width (or smaller), which is stable for the usual tearing mode. Interestingly, examination of the eigenfunctions of the velocity perturbation and the magnetic field perturbation indicates that the streaming tearing mode carries more energy in terms of the kinetic energy rather than the magnetic energy. This suggests that the streaming tearing mode instability can be a more feasible mechanism of plasma acceleration than the usual tearing mode instability.

  12. DNR 24K Streams

    Data.gov (United States)

    Minnesota Department of Natural Resources — 1:24,000 scale streams captured from USGS seven and one-half minute quadrangle maps, with perennial vs. intermittent classification, and connectivity through lakes,...

  13. Trout Stream Special Regulations

    Data.gov (United States)

    Minnesota Department of Natural Resources — This layer shows Minnesota trout streams that have a special regulation as described in the 2006 Minnesota Fishing Regulations. Road crossings were determined using...

  14. Scientific stream pollution analysis

    National Research Council Canada - National Science Library

    Nemerow, Nelson Leonard

    1974-01-01

    A comprehensive description of the analysis of water pollution that presents a careful balance of the biological,hydrological, chemical and mathematical concepts involved in the evaluation of stream...

  15. Collaborative Media Streaming

    OpenAIRE

    Kahmann, Verena

    2008-01-01

    Mit Hilfe der IP-Technologie erbrachte Multimedia-Dienste wie IPTV oder Video-on-Demand sind zur Zeit ein gefragtes Thema. Technisch werden solche Dienste unter dem Begriff "Streaming" eingeordnet. Ein Server sendet Mediendaten kontinuierlich an Empfänger, welche die Daten sofort weiterverarbeiten und anzeigen. Über einen Rückkanal hat der Kunde die Möglichkeit der Einflussnahme auf die Wiedergabe. Eine Weiterentwicklung dieser Streaming-Dienste ist die Möglichkeit, gemeinsam mit anderen dens...

  16. Vascular endothelial growth factors: A comparison between invertebrates and vertebrates.

    Science.gov (United States)

    Kipryushina, Yulia O; Yakovlev, Konstantin V; Odintsova, Nelly A

    2015-12-01

    This review aims to summarize recent data concerning the structure and role of the members of the vascular endothelial growth factor (VEGF) and vascular endothelial growth factor receptor (VEGFR) families in the context of early development, organogenesis and regeneration, with a particular emphasis on the role of these factors in the development of invertebrates. Homologs of VEGF and/or VEGFR have been found in all Eumetazoa, in both Radiata and Bilateria, where they are expressed in the descendants of different germ layers and play a pivotal role in the development of animals with and without a vascular system. VEGF is a well-known angiogenesis regulator, but this factor also control cell migration during neurogenesis and the development of branching organs (the trachea) in invertebrate and vertebrate species. A possible explanation for the origin of Vegf/Vegfr in the animal kingdom and a pathway of Vegf/Vegfr evolution are discussed. Copyright © 2015 Elsevier Ltd. All rights reserved.

  17. Lessons from Digestive-Tract Symbioses Between Bacteria and Invertebrates.

    Science.gov (United States)

    Graf, Joerg

    2016-09-08

    In most animals, digestive tracts harbor the greatest number of bacteria in the animal that contribute to its health: by aiding in the digestion of nutrients, provisioning essential nutrients and protecting against colonization by pathogens. Invertebrates have been used to enhance our understanding of metabolic processes and microbe-host interactions owing to experimental advantages. This review describes how advances in DNA sequencing technologies have dramatically altered how researchers investigate microbe-host interactions, including 16S rRNA gene surveys, metagenome experiments, and metatranscriptome studies. Advantages and challenges of each of these approaches are described herein. Hypotheses generated through omics studies can be directly tested using site-directed mutagenesis, and findings from transposon studies and site-directed experiments are presented. Finally, unique structural aspects of invertebrate digestive tracts that contribute to symbiont specificity are presented. The combination of omics approaches with genetics and microscopy allows researchers to move beyond correlations to identify conserved mechanisms of microbe-host interactions.

  18. The involvement of metallothionein in the development of aquatic invertebrate

    International Nuclear Information System (INIS)

    Mao Huan; Wang Dahui; Yang Wanxi

    2012-01-01

    The many documents on metallothioneins (MTs) in aquatic organisms focus especially on their use as biomarkers in environmental monitoring programs, but there are a few papers that summarize the physiological role of MTs in aquatic organisms especially in their development. The multifaceted role of MTs include involvement in homeostasis, protection against heavy metals and oxidant damage, metabolic regulation, sequestration and/or redox control. MTs could be induced by heavy metals which are able to hinder gametogenesis, suppress embryogenesis, and hamper development. Here we pay more attention on the non-essential metal cadmium, which is the most studied heavy metal regarding MTs, and its effects on the development of aquatic invertebrates. In this paper, we have collected published information on MTs in aquatic organisms – mollusks, crustaceans, etc., and summarize its functions in aquatic invertebrates, especially those related to their development.

  19. Transuranic biokinetic parameters for marine invertebrates--a review.

    Science.gov (United States)

    Ryan, T P

    2002-04-01

    A catalogue of biokinetic parameters for the transuranic elements plutonium, americium, curium, neptunium, and californium in marine invertebrates is presented. The parameters considered are: the seawater-animal concentration factor (CF); the sediment-animal concentration ratio (CR); transuranic assimilation efficiency; transuranic tissue distribution and transuranic elimination rates. With respect to the seawater-animal CF, authors differ considerably on how they define this parameter and a seven-point reporting system is suggested. Transuranic uptake from sediment by animals is characterised by low CRs. The assimilation efficiencies of transuranic elements in marine invertebrates are high compared to vertebrates and mammals in general and the distribution of transuranics within the body tissue of an animal is dependent on the uptake path. The elimination of transuranics from most species examined conformed to a standard biphasic exponential model though some examples with three elimination phases were identified.

  20. Enterococcus infection biology: lessons from invertebrate host models.

    Science.gov (United States)

    Yuen, Grace J; Ausubel, Frederick M

    2014-03-01

    The enterococci are commensals of the gastrointestinal tract of many metazoans, from insects to humans. While they normally do not cause disease in the intestine, they can become pathogenic when they infect sites outside of the gut. Recently, the enterococci have become important nosocomial pathogens, with the majority of human enterococcal infections caused by two species, Enterococcus faecalis and Enterococcus faecium. Studies using invertebrate infection models have revealed insights into the biology of enterococcal infections, as well as general principles underlying host innate immune defense. This review highlights recent findings on Enterococcus infection biology from two invertebrate infection models, the greater wax moth Galleria mellonella and the free-living bacteriovorous nematode Caenorhabditis elegans.

  1. Crustal growth history of the Korean Peninsula:Constraints from detrital zircon ages in modern river sediments

    Institute of Scientific and Technical Information of China (English)

    Taejin Choi; Yong Il Lee; Yuji Orihashi

    2016-01-01

    U-Pb analyses were carried out on detrital zircon grains from major river-mouth sediments draining South Korea to infer provenance characteristics and the crustal growth history of the southern Korean Peninsula, using a laser ablation inductively coupled plasma mass spectrometer (LA-ICP-MS). The Korean Peninsula is located in the East Asian continental margin and mainly comprises three Precambrian massifs and two metamorphic belts in between them. We obtained 515 concordant to slightly discordant zircon ages ranging from ca. 3566 to ca. 48 Ma. Regardless of river-mouth location, predominance of Mesozoic (249e79 Ma) and Paleoproterozoic (2491e1691 Ma) ages with subordinate Archean ages in-dicates that the zircon ages reflect present exposures of plutonic/metamorphic rocks in the drainage basins of the South Korean rivers and the crustal growth of the southern Korean Peninsula was focused in these two periods. Comparison of detrital zircon-age data between the North and South Korean river sediments reveals that the Paleoproterozoic zircon age distributions of both regions are nearly identical, while the NeoproterozoicePaleozoic ages exist and the Mesozoic ages are dominant in southern Korean Peninsula. This result suggests that Precambrian terrains in Korea record the similar pre-Mesozoic magmatic history and that the influence of Mesozoic magmatism was mainly focused in South Korea.

  2. Triassic North American paleodrainage networks and sediment dispersal of the Chinle Formation: A quantitative approach utilizing detrital zircons

    Science.gov (United States)

    Blum, M. D.; Umbarger, K.

    2017-12-01

    The Triassic Chinle Formation is a fluvial succession deposited in a backarc setting across the present-day Colorado Plateau of the southwestern United States. Existing studies have proposed various mechanisms responsible for the unique stratigraphic architecture and depositional sequences of the Chinle. However, these studies lack necessary age control to correlate stratigraphic patterns with contemporaneous mechanisms. This study will collect new samples for detrital zircon analysis, as well as upgrade existing samples (to n=300) from Dickinson and Gehrels (2008), to improve the resolution of Triassic sediment provenance from source-to-sink. The improved dataset allows appraisal of the multiple provenance terranes that contributed to the Chinle depositional system to delineate and reconstruct paleodrainage patterns. The additional samples will be collected systematically from the base of the Chinle, and vertically throughout the section to capture a regional story of how the continental scale drainage reorganized through time. U-Pb ages of detrital zircons will be utilized to provide quantitative fingerprinting information to constrain interpretations for the origin and transport history of the Chinle fluvial succession in time and space.

  3. Breeding Westland petrels as providers of detrital carbon and nitrogen for soil arthropods : a stable isotope study

    International Nuclear Information System (INIS)

    Hawke, D.J.; Clark, J.M.; Vallance, J.R.

    2013-01-01

    Seabirds deposit large quantities of marine detritus on land, but little is known of the soil arthropods processing this material. Burrow-nesting seabirds concentrate their activities within their burrows, so we tested the hypothesis that burrow arthropod fauna is more marine-like in its isotopic enrichment ( 13 C/ 12 C, 15 N/ 14 N); expressed as δ 13 C and δ 15 N) than the arthropods on the adjacent forest floor. Results from a Westland petrel (Procellaria westlandica) colony on the South Island of New Zealand did not support the hypothesis. Instead, δ 15 N was universally marine (13-22 per mil). While δ 13 C separated into two clusters, the distribution was not according to arthropod provenance. Most taxa had a terrestrial δ 13 C; only two taxa (a leiodid beetle and the mesostigmatic mite Ayersacarus woodi) incorporated marine C. The leiodid beetle occurs both in burrows and on the forest floor; beetles from both habitats had a marine δ 13 C. Ayersacarus woodi is found only in burrows. We conclude that, in this system, marine and terrestrial detrital C is processed separately, and that marine detrital C enters the terrestrial ecosystem through a very few arthropod taxa. (author). 33 refs., 1 fig.

  4. Frequent Prescribed Burning as a Long-term Practice in Longleaf Pine Forests Does Not Affect Detrital Chemical Composition.

    Science.gov (United States)

    Coates, T Adam; Chow, Alex T; Hagan, Donald L; Wang, G Geoff; Bridges, William C; Dozier, James H

    2017-09-01

    The O horizon, or detrital layer, of forest soils is linked to long-term forest productivity and health. Fuel reduction techniques, such as prescribed fire, can alter the thickness and composition of this essential ecosystem component. Developing an understanding of the changes in the chemical composition of forest detritus due to prescribed fire is essential for forest managers and stakeholders seeking sustainable, resilient, and productive ecosystems. In this study, we evaluated fuel quantity, fuel structure, and detrital chemical composition in longleaf pine ( Miller) forests that have been frequently burned for the last 40 yr at the Tom Yawkey Wildlife Center in Georgetown, SC. Our results suggest that frequent prescribed fire reduces forest fuel quantity ( burned detritus. Our burning activities varied in the short term, consisting of annual dormant, annual growing, and biennial dormant season burns. Seasonal distinctions were present for fuel quantity and vertical fuel structure, but these differences were not noted for the benzene/phenol ratio. These results are significant as more managers consider burning existing longleaf stands while determining effective management practices for longleaf stands yet to be established. Managers of such stands can be confident that frequent, low-intensity, low-severity prescribed burns in longleaf pine forests do little to affect the long-term chemical composition of forest detritus. Copyright © by the American Society of Agronomy, Crop Science Society of America, and Soil Science Society of America, Inc.

  5. Potential impacts of the energy industry on invertebrates

    Energy Technology Data Exchange (ETDEWEB)

    DeMont, E. [Saint Francis Xavier Univ., Antigonish, NS (Canada). Dept. of Biology

    2006-07-01

    This presentation provided a literature review of seismic activity impacts on invertebrates. A summary of recent research on the effects of seismic noise on female snow crab (Chionoecetes opilio) was evaluated by comparison with a caging study conducted off western Cape Breton Island in 2003-2004 which examined mortality and external damages to crabs, as well as the conditions of appendices and organs. Details of a study examining the mobility of lobsters over pipelines were presented, as well as recent research conducted by the St. Francis Xavier Biomechanics Laboratory. It was noted that studies on the effects of marine noise on invertebrate species are limited and incomplete. However, the impacts of marine noise on invertebrates is a critical issue for major fisheries based on invertebrates. The snow crab study showed swelling of hepatopancreatic walls to crabs in areas of seismic activity. Abundance and distribution of the crabs fell from 30 per cent before seismic activity to 23 per cent after seismic exploration began. Evidence of immediate impacts on antennules, gill and statocysts which lasted less than 5 months was observed. The impacts of the abnormalities on the life cycle of the crabs is unknown. Exposure to seismic energy did not kill snow crab embryos. However, rates of development were slower in seismic than control embryos. Results suggested that further research on normal crab health and environmental conditions is needed. Current research at the St. Francis Xavier Biomechanics Laboratory included a fluid mechanics study paddle-assisted walking for lobsters; jet-assisted walking in lobsters; the effects of temperature on the activity of lobsters; and, the impact of mechanical vibrations on lobsters. Details of sponsors for the various studies were also provided. refs., tabs., figs.

  6. Photon activation analysis of soft tissues of marine invertebrates

    International Nuclear Information System (INIS)

    Fukushima, M.; Tamate, H.

    2001-01-01

    We have determined levels of elements in soft tissues of 23 species of marine invertebrates by photon activation analysis and atomic absorption spectrometry. Concentration levels of Mg and Rb were almost same for all samples determined. On the contrary, relatively high concentration of elements were observed for Ni in mid-gut gonads of ear shells, As in gills, hepatopancreas, and muscles of several species of Crustaceans. (author)

  7. Impact of Invertebrate Herbivory on Native Aquatic Macrophytes

    Science.gov (United States)

    2007-08-01

    this macroalga occupied the entire water column, it may have had a competitive advantage for light over V. americana, which grew closer to the...dry biomass of five macrophyte species between two treatments ; an insecticide treatment to remove invertebrate herbivores, and a control where the...Heitmeyer and Vohs 1984, Dibble et al. 1996), improve water clarity and quality, and reduce rates of shoreline erosion and sediment resuspension (Smart

  8. Streaming Pool: reuse, combine and create reactive streams with pleasure

    CERN Multimedia

    CERN. Geneva

    2017-01-01

    When connecting together heterogeneous and complex systems, it is not easy to exchange data between components. Streams of data are successfully used in industry in order to overcome this problem, especially in the case of "live" data. Streams are a specialization of the Observer design pattern and they provide asynchronous and non-blocking data flow. The ongoing effort of the ReactiveX initiative is one example that demonstrates how demanding this technology is even for big companies. Bridging the discrepancies of different technologies with common interfaces is already done by the Reactive Streams initiative and, in the JVM world, via reactive-streams-jvm interfaces. Streaming Pool is a framework for providing and discovering reactive streams. Through the mechanism of dependency injection provided by the Spring Framework, Streaming Pool provides a so called Discovery Service. This object can discover and chain streams of data that are technologically agnostic, through the use of Stream IDs. The stream to ...

  9. Brown World Invertebrates Contradict Green World Biodiversity Theory

    International Nuclear Information System (INIS)

    Patrick, L.B.; Kershner, M.W.; Fraser, L.H.

    2008-01-01

    Biodiversity-productivity theory predicts that ecosystems with increased productivity due to excessive limiting-nutrient loading will have decreased taxonomic diversity. In this 4-year study, we elevated productivity by adding NPK fertilizer to 20 m diameter plots in an old-field grassland to test the effects of anthropogenically mediated nutrient loading on plant and epigeal arthropod communities. While plants responded as predicted by the biodiversity-productivity theory, the epigeal arthropod community had highest species richness within the fertilized high-productivity treatments. We conclude that the contradictory response of the largely detrital-based epigeal community should alter conventional biodiversity-productivity theory and could affect terrestrial biodiversity conservation strategies.

  10. Soil macrofauna (invertebrates of Kazakhstanian Stipa lessingiana dry steppe

    Directory of Open Access Journals (Sweden)

    Bragina Tatyana М.

    2016-12-01

    Full Text Available Stipa lessingiana steppes used to be prevalent on the dry Trans-Ural denudation plains, particularly, on the Sub-Ural and the Turgay Plateau. But, most of them have been lost because they were plowed up during the Virgin Land campaign in the second part of 20th century. This paper presents a detailed study of the faunistic composition and the structure of soil-dwelling invertebrate communities (macrofauna of a temperate-dry bunch feather grass steppe in the Turgai Plateau (Northern-Turgai physical-geographical province of steppe Kazakhstan, Kostanay Oblast. The study site is located in the territory of the Naurzum State Nature Reserve, a part of the UNESCO World Heritage site “Saryarka Steppe and Lakes of Northern Kazakhstan”, where remnants of Virgin S. lessingiana steppes have been preserved to the present day. This region is the driest and most continental in climate of all the dry steppes of Kazakhstan. The total abundance and biomass of soil invertebrate communities in the investigated site were lower than in the northern and western steppe areas. Soil invertebrates are among the major components that determine the functioning of terrestrial natural ecosystems.

  11. Toxicity of abamectin and doramectin to soil invertebrates

    International Nuclear Information System (INIS)

    Kolar, Lucija; Kozuh Erzen, Nevenka; Hogerwerf, Lenny; Gestel, Cornelis A.M. van

    2008-01-01

    This study aimed at determining the toxicity of avermectins to soil invertebrates in soil and in faeces from recently treated sheep. Abamectin was more toxic than doramectin. In soil, earthworms (Eisenia andrei) were most affected with LC50s of 18 and 228 mg/kg dry soil, respectively, while LC50s were 67-111 and >300 mg/kg for springtails (Folsomia candida), isopods (Porcellio scaber) and enchytraeids (Enchytraeus crypticus). EC50s for the effect on reproduction of springtails and enchytraeids were 13 and 38 mg/kg, respectively for abamectin, and 42 and 170 mg/kg for doramectin. For earthworms, NOEC was 10 and 8.4 mg/kg for abamectin and doramectin effects on body weight. When exposed in faeces, springtails and enchytraeids gave LC50s and EC50s of 1.0-1.4 and 0.94-1.1 mg/kg dry faeces for abamectin and 2.2->2.4 mg/kg for doramectin. Earthworm reproduction was not affected. This study indicates a potential risk of avermectins for soil invertebrates colonizing faeces from recently treated sheep. - Avermectins may pose a risk to soil invertebrates colonizing faeces from recently treated sheep

  12. Biometry of neotropical invertebrates inhabiting floodplain rivers: unraveling bionomy

    Directory of Open Access Journals (Sweden)

    Florencia Zilli

    Full Text Available ABSTRACT Currently, it is widely recognized that invertebrates play key roles in neotropical floodplains and in many other environments worldwide. However, little information has been published concerning their biometry, in spite that it represents an essential tool for many different studies. Here, we provided length-mass and length-length relationships by fitting the linearized model (log10 Y = log10a + b log10 X and several mean biomass ratios ± SE for bivalves, gastropods, quironomids, ephemeropterans, oligochaetes and hirudineans. We measured, weighed, oven dried and incinerated to ashes specimens collected from 2005 to 2014 in the Paraná River, Argentina. The lineal equations had fit levels higher than 75% in most of the significant regressions. Hence, when slopes were compared, differences raised from ontogeny and phylogeny of taxa. Additionally, slopes resulted different from constants of other regions, types of environments and climates. In addition, organic matter ratios resulted significantly different among invertebrates according to their feeding types. The equations and ratios that we provided will facilitate future research on life history, productivity and energy transference in the food webs of invertebrates inhabiting floodplain wetlands and can be used as tools for planning management strategies and in restoration projects of aquatic environments.

  13. Chemical defense of early life stages of benthic marine invertebrates.

    Science.gov (United States)

    Lindquist, Niels

    2002-10-01

    Accurate knowledge of factors affecting the survival of early life stages of marine invertebrates is critically important for understanding their population dynamics and the evolution of their diverse reproductive and life-history characteristics. Chemical defense is an important determinant of survival for adult stages of many sessile benthic invertebrates, yet relatively little consideration has been given to chemical defenses at the early life stages. This review examines the taxonomic breadth of early life-stage chemical defense in relation to various life-history and reproductive characteristics, as well as possible constraints on the expression of chemical defense at certain life stages. Data on the localization of defensive secondary metabolites in larvae and the fitness-related consequences of consuming even a small amount of toxic secondary metabolites underpin proposals regarding the potential for Müllerian and Batesian mimicry to occur among marine larvae. The involvement of microbial symbionts in the chemical defense of early life stages illustrates its complexity for some species. As our knowledge of chemical defenses in early life stages grows, we will be able to more rigorously examine connections among phylogeny, chemical defenses, and the evolution of reproductive and life-history characteristics among marine invertebrates.

  14. Toxicity of abamectin and doramectin to soil invertebrates

    Energy Technology Data Exchange (ETDEWEB)

    Kolar, Lucija [Laboratory of Forensic Toxicology and Ecotoxicology, Veterinary Faculty, University of Ljubljana, Gerbiceva 60, SI-1000 Ljubljana (Slovenia); Institute of Ecological Science, Vrije Universiteit, De Boelelaan 1085, 1081 HV Amsterdam (Netherlands)], E-mail: lucija.kolar@vf.uni-lj.si; Kozuh Erzen, Nevenka [Laboratory of Forensic Toxicology and Ecotoxicology, Veterinary Faculty, University of Ljubljana, Gerbiceva 60, SI-1000 Ljubljana (Slovenia)], E-mail: nevenka.kozuh@vf.uni-lj.si; Hogerwerf, Lenny [Institute of Ecological Science, Vrije Universiteit, De Boelelaan 1085, 1081 HV Amsterdam (Netherlands)], E-mail: l.hogerwerf@students.uu.nl; Gestel, Cornelis A.M. van [Institute of Ecological Science, Vrije Universiteit, De Boelelaan 1085, 1081 HV Amsterdam (Netherlands)], E-mail: kees.van.gestel@ecology.falw.vu.nl

    2008-01-15

    This study aimed at determining the toxicity of avermectins to soil invertebrates in soil and in faeces from recently treated sheep. Abamectin was more toxic than doramectin. In soil, earthworms (Eisenia andrei) were most affected with LC50s of 18 and 228 mg/kg dry soil, respectively, while LC50s were 67-111 and >300 mg/kg for springtails (Folsomia candida), isopods (Porcellio scaber) and enchytraeids (Enchytraeus crypticus). EC50s for the effect on reproduction of springtails and enchytraeids were 13 and 38 mg/kg, respectively for abamectin, and 42 and 170 mg/kg for doramectin. For earthworms, NOEC was 10 and 8.4 mg/kg for abamectin and doramectin effects on body weight. When exposed in faeces, springtails and enchytraeids gave LC50s and EC50s of 1.0-1.4 and 0.94-1.1 mg/kg dry faeces for abamectin and 2.2->2.4 mg/kg for doramectin. Earthworm reproduction was not affected. This study indicates a potential risk of avermectins for soil invertebrates colonizing faeces from recently treated sheep. - Avermectins may pose a risk to soil invertebrates colonizing faeces from recently treated sheep.

  15. Lessons in modularity: the evolutionary ecology of colonial invertebrates

    Directory of Open Access Journals (Sweden)

    Roger N. Hughes

    2005-06-01

    Full Text Available Benthic colonial invertebrates share with higher plants a modular construction and a sessile adult life. Both types of organism show parallel evolutionary responses to common selective forces, but in contrast to the long-established focus on plants, comparable study of colonial invertebrates has developed relatively recently, largely owing to the application of new techniques in image processing and molecular biology. Species whose life cycles are readily completed under laboratory conditions and whose colonies are easily propagated from cuttings provide powerful models for experimentally investigating fundamental evolutionary problems, including metabolic allometry, the manifestation of ageing and the origin of allorecognition systems. Free of the confounding influences of behavioural manipulation and costs of copulation, colonial invertebrates whose water-borne sperm fertilize retained eggs lend themselves well to the experimental study of cryptic female choice, sperm competition and sexual conflict. In these respects, it will be productive to adopt and extend theoretical frameworks developed for flowering plants to guide experimental investigation of modular animals. Since mate choice occurs at the cellular level in modular animals, reproductive isolation is uncorrelated with morphology and cryptic speciation is likely to be widespread.

  16. Evaluating pesticide effects on freshwater invertebrate communities in alpine environment: a model ecosystem experiment.

    Science.gov (United States)

    Ippolito, A; Carolli, M; Varolo, E; Villa, S; Vighi, M

    2012-10-01

    Pesticide loads in streams are potentially one of the most relevant stressors for macroinvertebrate communities. Nevertheless, real effects provoked at the community level are still largely unknown. Model ecosystems are frequently used as tools for the risk assessment of pesticides, especially for their regulation, however, they can be also applied to site-specific risk assessment in order to gain better understanding of the responses of aquatic ecosystems to chemical stress. In the present work, an experimental system was composed of 5 artificial streams that reproduced a mountain lotic environment under controlled conditions. This study was aimed to better understand, whether (and how) the biological community was influenced by pesticides pulse exposures. 5 mixture load events were simulated over the productive season (March-July 2010): biological community was regularly sampled and nominal concentrations of water were tested. The results were interpreted comparing the output of different metrics and statistical methodologies. The sensitivity of different metrics was analyzed considering single exposure events (maximum Toxic Units) as well as overall temporal trends. Results showed how some common taxonomic metrics (e.g. taxa richness, Shannon's index, total abundance of organisms, and the Extended Biotic Index) were not suitable to identify the effects of pesticides at community level. On the contrary EPT%, SPEAR(pesticide) and the Principal Response Curve methodology proved to be sensitive to this kind of stress, providing comparable results. Temporal trends of these metrics proved to be related to the concentration of chemicals. Remarkably, the first Principal Response Curve illustrates the trend followed by the most vulnerable species, while the second is more related to the trend of opportunistic species. A high potential risk for the invertebrate community was highlighted by a statistically significant decline of 40 points (comparison with the control) in

  17. Do stage-specific functional responses of consumers dampen the effects of subsidies on trophic cascades in streams?

    Science.gov (United States)

    Sato, Takuya; Watanabe, Katsutoshi

    2014-07-01

    Resource subsidies often weaken trophic cascades in recipient communities via consumers' functional response to the subsidies. Consumer populations are commonly stage-structured and may respond to the subsidies differently among the stages yet less is known about how this might impact the subsidy effects on the strength of trophic cascades in recipient systems. We show here, using a large-scale field experiment, that the stage structure of a recipient consumer would dampen the effects of terrestrial invertebrate subsidies on the strength of trophic cascade in streams. When a high input rate of the terrestrial invertebrates was available, both large and small fish stages switched their diet to the terrestrial subsidy, which weakened the trophic cascade in streams. However, when the input rate of the terrestrial invertebrates was at a moderate level, the terrestrial subsidy did not weaken the trophic cascade. This discrepancy was likely due to small fish stages being competitively excluded from feeding on the subsidy by larger stages of fish and primarily foraging on benthic invertebrates under the moderate input level. Although previous studies using single fish stages have clearly demonstrated that the terrestrial invertebrate input equivalent to our moderate input rate weakened the trophic cascade in streams, this subsidy effect might be overestimated given small fish stage may not switch their diet to the subsidy under competition with large fish stage. Given the ubiquity of consumer stage structure and interaction among consumer stages, the effects we saw might be widespread in nature, requiring future studies that explicitly involve consumer's stage structure into community ecology. © 2013 The Authors. Journal of Animal Ecology © 2013 British Ecological Society.

  18. Streams and their future inhabitants

    DEFF Research Database (Denmark)

    Sand-Jensen, K.; Friberg, Nikolai

    2006-01-01

    In this fi nal chapter we look ahead and address four questions: How do we improve stream management? What are the likely developments in the biological quality of streams? In which areas is knowledge on stream ecology insuffi cient? What can streams offer children of today and adults of tomorrow?...

  19. Effectiveness of stream-sediment sampling along the Rio Ojo Caliente, New Mexico

    International Nuclear Information System (INIS)

    Wenrich-Verbeek, K.J.

    1977-01-01

    During 1976 a detailed geochemical study was conducted of the water and stream sediments in the tributaries of the Rio Ojo Caliente above the USGS gaging station 4 km below La Madera to determine: (1) the source of the anomaly in the water and (2) why the stream sediment samples did not contain a corresponding anomaly. The low uranium content of the stream sediments from these high uranium waters can be explained by (1) the presence of a ground water source for the uranium and (2) insufficient time for the uranium in the water to be adsorbed onto the sediments. Although a stream sediment anomaly in the streams containing high uranium waters can not be established with a size fraction less than 150 μm, enough uranium has been adsorbed by the fine fraction that a small local anomaly can be outlined using only the fraction size less than 90 μm. Thus, because adsorption appears to be a major control on the uranium in the fine fraction and detrital minerals control the uranium in the coarse fraction, if it is assumed that buried deposits are of prime importance because most surface deposits have been recognized, then sampling should be restricted to the fine fraction (less than 90 μm). Nevertheless, in a case where ground water is the contributing source for uranium, as was shown above by the low anomalous uranium values, even in the fine fraction, stream sediment sampling alone is not an effective technique for detecting uranium anomalies. This emphasizes the necessity of water sampling in conjunction with stream-sediment sampling

  20. Effect of land use on the composition, diversity and abundance of insects drifting in neotropical streams

    Directory of Open Access Journals (Sweden)

    B. C. G. Gimenez

    Full Text Available Abstract Streams may exhibit differences in community structure of invertebrate drift, which may be a reflex of variation in environmental factors, able to change in conditions of anthropogenic interventions. The aim of this study was to analyze the composition, diversity and abundance of insects drifting in two neotropical streams under different land use and to identify the environmental factors involved in determining such patterns. 54 taxa of aquatic insects were identified in urban and rural streams. The results indicated significant differences in species composition due to the replacement of specialist species by generalist species in the urban stream. Higher diversity of taxa was recorded in the rural stream, with high levels of dissolved oxygen and high water flow, which favored the occurrence of sensitive groups to environmental disturbances, such as Ephemeroptera, Plecoptera, Trichoptera and Coleoptera taxa, that living mainly in clean and well oxygenated waters. On the other hand, a higher density of insects drifting, especially Chironomidae, was observed in the urban stream, where high values of pH, electrical conductivity and nitrogen were observed. These larvae are able to explore a wide range of environmental conditions, owing to their great capacity for physiological adaptation. Despite observing the expected patterns, there were no significant differences between streams for the diversity and abundance of species. Thus, the species composition can be considered as the best predictor of impacts on the drifting insect community.

  1. Effect of oil palm on the Plecoptera and Trichoptera (Insecta) assemblages in streams of eastern Amazon.

    Science.gov (United States)

    de Paiva, Carina Kaory Sasahara; de Faria, Ana Paula Justino; Calvão, Lenize Batista; Juen, Leandro

    2017-08-01

    The production of oil palm is expected to increase in the Amazon region. However, expansion of oil palm plantation leads to significant changes in the physical structure of aquatic ecosystems, mainly through the reduction of riparian vegetation that is essential for aquatic biodiversity. Here, we evaluated the effects of oil palm on the physical habitat structure of Amazonian stream environments and assemblages of Plecoptera and Trichoptera (PT), ​both found in these streams. We compared streams sampled in oil palm plantations (n = 13) with natural forest areas ("reference" streams, n = 8), located in the eastern Amazon, Brazil. Our results showed that oil palm streams were more likely to be in close proximity to roads, had higher pH values, and higher amounts of fine substrate deposited in the channel than reference streams. Further, these environmental changes had important effects on the aquatic invertebrate assemblages, reducing the abundance and richness of PT. Nevertheless, the genera composition of the assemblages did not differ between reference and oil palm (PERMANOVA, pseudo-F (1,19)  = 1.891; p = 0.111). We conclude that oil palm production has clear negative impacts on aquatic environments and PT assemblages in Amazonian streams. We recommend that oil palm producers invest more in planning of road networks to avoid the construction of roads near to the riparian vegetation. This planning can minimize impacts of oil palm production on aquatic systems in the Amazon.

  2. Multiple stressors in agricultural streams: a mesocosm study of interactions among raised water temperature, sediment addition and nutrient enrichment.

    Directory of Open Access Journals (Sweden)

    Jeremy J Piggott

    Full Text Available Changes to land use affect streams through nutrient enrichment, increased inputs of sediment and, where riparian vegetation has been removed, raised water temperature. We manipulated all three stressors in experimental streamside channels for 30 days and determined the individual and pair-wise combined effects on benthic invertebrate and algal communities and on leaf decay, a measure of ecosystem functioning. We added nutrients (phosphorus+nitrogen; high, intermediate, natural and/or sediment (grain size 0.2 mm; high, intermediate, natural to 18 channels supplied with water from a nearby stream. Temperature was increased by 1.4°C in half the channels, simulating the loss of upstream and adjacent riparian shade. Sediment affected 93% of all biological response variables (either as an individual effect or via an interaction with another stressor generally in a negative manner, while nutrient enrichment affected 59% (mostly positive and raised temperature 59% (mostly positive. More of the algal components of the community responded to stressors acting individually than did invertebrate components, whereas pair-wise stressor interactions were more common in the invertebrate community. Stressors interacted often and in a complex manner, with interactions between sediment and temperature most common. Thus, the negative impact of high sediment on taxon richness of both algae and invertebrates was stronger at raised temperature, further reducing biodiversity. In addition, the decay rate of leaf material (strength loss accelerated with nutrient enrichment at ambient but not at raised temperature. A key implication of our findings for resource managers is that the removal of riparian shading from streams already subjected to high sediment inputs, or land-use changes that increase erosion or nutrient runoff in a landscape without riparian buffers, may have unexpected effects on stream health. We highlight the likely importance of intact or restored buffer

  3. Endocrine Function in Aquatic Invertebrates and Evidence for Disruption by Environmental Pollutants

    OpenAIRE

    Pinder, L. C. V.; Pottinger, T. G.; Billinghurst, Z.; Depledge, M. H.

    1999-01-01

    EXECUTIVE SUMMARY Objectives 1. This report addresses five primary objectives:- (i) to summarize the key elements of invertebrate endocrine systems; (ii) to assess whether existing test systems are adequate for the detection of endocrine disruption in invertebrates, what new tests might be required, which species of invertebrates are most appropriate for such tests, what end-points should be measured and whether the same organisms can be used for both laboratory and environme...

  4. Relationships of sedimentation and benthic macroinvertebrate assemblages in headwater streams using systematic longitudinal sampling at the reach scale.

    Science.gov (United States)

    Longing, S D; Voshell, J R; Dolloff, C A; Roghair, C N

    2010-02-01

    Investigating relationships of benthic invertebrates and sedimentation is challenging because fine sediments act as both natural habitat and potential pollutant at excessive levels. Determining benthic invertebrate sensitivity to sedimentation in forested headwater streams comprised of extreme spatial heterogeneity is even more challenging, especially when associated with a background of historical and intense watershed disturbances that contributed unknown amounts of fine sediments to stream channels. This scenario exists in the Chattahoochee National Forest where such historical timber harvests and contemporary land-uses associated with recreation have potentially affected the biological integrity of headwater streams. In this study, we investigated relationships of sedimentation and the macroinvertebrate assemblages among 14 headwater streams in the forest by assigning 30, 100-m reaches to low, medium, or high sedimentation categories. Only one of 17 assemblage metrics (percent clingers) varied significantly across these categories. This finding has important implications for biological assessments by showing streams impaired physically by sedimentation may not be impaired biologically, at least using traditional approaches. A subsequent multivariate cluster analysis and indicator species analysis were used to further investigate biological patterns independent of sedimentation categories. Evaluating the distribution of sedimentation categories among biological reach clusters showed both within-stream variability in reach-scale sedimentation and sedimentation categories generally variable within clusters, reflecting the overall physical heterogeneity of these headwater environments. Furthermore, relationships of individual sedimentation variables and metrics across the biological cluster groups were weak, suggesting these measures of sedimentation are poor predictors of macroinvertebrate assemblage structure when using a systematic longitudinal sampling design

  5. U-Pb SHRIMP ages of detrital zircons from Hiriyur formation in Chitradurga Greenstone belt and its implication to the Neoarchean evolution of Dharwar craton, South India

    International Nuclear Information System (INIS)

    Nasheeth, A.; Okudaira, T.; Horie, K.; Hokada, T.; Satish Kumar, M.

    2016-01-01

    We report newly obtained U-Pb SHRIMP ages of detrital zircons from metagreywackes in the Hiriyur Formation (Chitradurga Group, Dharwar Supergroup) from the central eastern part of the Chitradurga greenstone belt. U-Pb analyses yield three major Neoarchean age populations ranging from 2.70 - 2.54 Ga with some minor age population of Mesoarchean. The maximum age of deposition is constrained by the youngest detrital zircon population at 2546 Ma. This is the first report of the occurrence of supracrustal rocks less than 2.58 Ga in the central part of Chitradurga greenstone belt. Close evaluation of detrital ages with the published ages of surrounding igneous rocks suggest that the youngest detrital zircons might be derived from rocks of the Eastern Dharwar craton and the inferred docking of the western and eastern Dharwar cratons happened prior to the deposition of the Hiriyur Formation. The Chitradurga shear zone, dividing the Dharwar craton into western and eastern blocks, probably developed after the deposition. Furthermore, the lower intercept is interpreted as evidence for the Pan-African overprints in the study area. (author)

  6. Detrital zircon without detritus: a result of 496-Ma-old fluid-rock interaction during the gold-lode formation of Passagem, Minas Gerais, Brazil

    Science.gov (United States)

    Cabral, Alexandre Raphael; Zeh, Armin

    2015-01-01

    Zircon and xenotime occur in tourmaline-rich hydrothermal pockets in the auriferous lode of Passagem de Mariana, a world-class gold deposit. Zircon grains show pristine oscillatory zoning, but many of them are altered, exhibiting porous domains filled with graphite. Uranium-Pb dating of zircon, using in-situ laser ablation-inductively coupled plasma-mass spectrometry, yields ages between 3.2 and 2.65 Ga, which match those for detrital zircon of the footwall quartzite of the > 2.65-Ga-old Moeda Formation. Discordant analyses point to zircon-age resetting during the Brasiliano orogeny at ca. 500 Ma. This interpretation is supported by U-Pb dating of euhedral xenotime immediately adjacent to altered zircon within the same tourmaline pocket. The xenotime grains give a Concordia age of 496.3 ± 2.0 Ma, which is identical to that determined for monazite of a quartz-hematite vein-type deposit (i.e., jacutinga lode) in the region (Itabira), another important mineralisation style of gold. The occurrence of relatively abundant inherited detrital zircon, but absence of rock fragments in the tourmaline pocket investigated here, implies that detrital material was completely replaced by tourmaline. The graphite overprint on the altered detrital zircon attests to a reducing fluid, which was likely formed by fluid-rock interaction with carbonaceous phyllite of the Batatal Formation, the host rock of the Passagem lode.

  7. Recovery of invertebrate and vertebrate populations in a coal ash stressed drainage system

    Energy Technology Data Exchange (ETDEWEB)

    Cherry, D.S.

    1979-01-01

    The influence of coal-ash basin effluent on the densities of macrobenthic invertebrate and mosquitofish populations in a swamp drainage system was studied for 50 months. The density of the aquatic biota was periodically altered by heavy ash siltation, decreased pH due to fly ash, and by arsenic, copper, selenium and zinc associated with coal ash. Siltation was most influential in decreasing numbers of invertebrates, and lowered pH (from 7.2 to 5.5) more influential in decreasing mosquito fish and retarding recovery of invertebrates. An efficient primary-secondary retaining basin system enabled most invertebrate groups to recover their previous level of abundance.

  8. Significance of bacteria associated with invertebrates in drinking water distribution networks.

    Science.gov (United States)

    Wolmarans, E; du Preez, H H; de Wet, C M E; Venter, S N

    2005-01-01

    The implication of invertebrates found in drinking water distribution networks to public health is of concern to water utilities. Previous studies have shown that the bacteria associated with the invertebrates could be potentially pathogenic to humans. This study investigated the level and identity of bacteria commonly associated with invertebrates collected from the drinking water treatment systems as well as from the main pipelines leaving the treatment works. On all sampling occasions bacteria were isolated from the invertebrate samples collected. The highest bacterial counts were observed for the samples taken before filtration as was expected. There were, however, indications that optimal removal of invertebrates from water did not always occur. During the investigation, 116 colonies were sampled for further identification. The isolates represent several bacterial genera and species that are pathogenic or opportunistic pathogens of humans. Diarrhoea, meningitis, septicaemia and skin infections are among the diseases associated with these organisms. The estimated number of bacteria that could be associated with a single invertebrate (as based on average invertebrate numbers) could range from 10 to 4000 bacteria per organism. It can, therefore, be concluded that bacteria associated with invertebrates might under the worst case scenario pose a potential health risk to water users. In the light of the above findings it is clear that invertebrates in drinking water should be controlled at levels as low as technically and economically feasible.

  9. Significance of detrital zircons in upper Devonian ocean-basin strata of the Sonora allochthon and Lower Permian synorogenic strata of the Mina Mexico foredeep, central Sonora, Mexico

    Science.gov (United States)

    Poole, F.G.; Gehrels, G.E.; Stewart, John H.

    2008-01-01

    U-Pb isotopic dating of detrital zircons from a conglomeratic barite sandstone in the Sonora allochthon and a calciclastic sandstone in the Mina Mexico foredeep of the Minas de Barita area reveals two main age groups in the Upper Devonian part of the Los Pozos Formation, 1.73-1.65 Ga and 1.44-1.42 Ga; and three main age groups in the Lower Permian part of the Mina Mexico Formation, 1.93-1.91 Ga, 1.45-1.42 Ga, and 1.1-1.0 Ga. Small numbers of zircons with ages of 2.72-2.65 Ga, 1.30-1.24 Ga, ca. 2.46 Ga, ca. 1.83 Ga, and ca. 0.53 Ga are also present in the Los Pozos sandstone. Detrital zircons ranging in age from 1.73 to 1.65 Ga are considered to have been derived from the Yavapai, Mojave, and Mazatzal Provinces and their transition zones of the southwestern United States and northwestern Mexico. The 1.45-1.30 Ga detrital zircons were probably derived from scattered granite bodies within the Mojave and Mazatzal basement rocks in the southwestern United States and northwestern Mexico, and possibly from the Southern and Eastern Granite-Rhyolite Provinces of the southern United States. The 1.24-1.0 Ga detrital zircons are believed to have been derived from the Grenville (Llano) Province to the east and northeast or from Grenvilleage intrusions or anatectites to the north. Several detrital zircon ages ranging from 2.72 to 1.91 Ga were probably derived originally from the Archean Wyoming Province and Early Paleoproterozoic rocks of the Lake Superior region. These older detrital zircons most likely have been recycled one or more times into the Paleozoic sandstones of central Sonora. The 0.53 Ga zircon is believed to have been derived from a Lower Cambrian granitoid or meta-morphic rock northeast of central Sonora, possibly in New Mexico and Colorado, or Oklahoma. Detrital zircon geochronology suggests that most of the detritus in both samples was derived from Laurentia to the north, whereas some detritus in the Permian synorogenic foredeep sequence was derived from the

  10. Recovery of a mining-damaged stream ecosystem

    Directory of Open Access Journals (Sweden)

    Christopher A. Mebane

    2015-03-01

    Full Text Available Abstract This paper presents a 30+ year record of changes in benthic macroinvertebrate communities and fish populations associated with improving water quality in mining-influenced streams. Panther Creek, a tributary to the Salmon River in central Idaho, USA suffered intensive damage from mining and milling operations at the Blackbird Mine that released copper (Cu, arsenic (As, and cobalt (Co into tributaries. From the 1960s through the 1980s, no fish and few aquatic invertebrates could be found in 40 km of mine-affected reaches of Panther Creek downstream of the metals contaminated tributaries, Blackbird and Big Deer Creeks. Efforts to restore water quality began in 1995, and by 2002 Cu levels had been reduced by about 90%, with incremental declines since. Rainbow Trout (Oncorhynchus mykiss were early colonizers, quickly expanding their range as areas became habitable when Cu concentrations dropped below about 3X the U.S. Environmental Protection Agency’s biotic ligand model (BLM based chronic aquatic life criterion. Anadromous Chinook Salmon (O. tshawytscha and steelhead (O. mykiss have also reoccupied Panther Creek. Full recovery of salmonid populations occurred within about 12-years after the onset of restoration efforts and about 4-years after the Cu chronic criteria had mostly been met, with recovery interpreted as similarity in densities, biomass, year class strength, and condition factors between reference sites and mining-influenced sites. Shorthead Sculpin (Cottus confusus were slower than salmonids to disperse and colonize. While benthic macroinvertebrate biomass has increased, species richness has plateaued at about 70 to 90% of reference despite the Cu criterion having been met for several years. Different invertebrate taxa had distinctly different recovery trajectories. Among the slowest taxa to recover were Ephemerella, Cinygmula and Rhithrogena mayflies, Enchytraeidae oligochaetes, and Heterlimnius aquatic beetles. Potential

  11. InverPep: A database of invertebrate antimicrobial peptides.

    Science.gov (United States)

    Gómez, Esteban A; Giraldo, Paula; Orduz, Sergio

    2017-03-01

    The aim of this work was to construct InverPep, a database specialised in experimentally validated antimicrobial peptides (AMPs) from invertebrates. AMP data contained in InverPep were manually curated from other databases and the scientific literature. MySQL was integrated with the development platform Laravel; this framework allows to integrate programming in PHP with HTML and was used to design the InverPep web page's interface. InverPep contains 18 separated fields, including InverPep code, phylum and species source, peptide name, sequence, peptide length, secondary structure, molar mass, charge, isoelectric point, hydrophobicity, Boman index, aliphatic index and percentage of hydrophobic amino acids. CALCAMPI, an algorithm to calculate the physicochemical properties of multiple peptides simultaneously, was programmed in PERL language. To date, InverPep contains 702 experimentally validated AMPs from invertebrate species. All of the peptides contain information associated with their source, physicochemical properties, secondary structure, biological activity and links to external literature. Most AMPs in InverPep have a length between 10 and 50 amino acids, a positive charge, a Boman index between 0 and 2 kcal/mol, and 30-50% hydrophobic amino acids. InverPep includes 33 AMPs not reported in other databases. Besides, CALCAMPI and statistical analysis of InverPep data is presented. The InverPep database is available in English and Spanish. InverPep is a useful database to study invertebrate AMPs and its information could be used for the design of new peptides. The user-friendly interface of InverPep and its information can be freely accessed via a web-based browser at http://ciencias.medellin.unal.edu.co/gruposdeinvestigacion/prospeccionydisenobiomoleculas/InverPep/public/home_en. Copyright © 2016 International Society for Chemotherapy of Infection and Cancer. Published by Elsevier Ltd. All rights reserved.

  12. 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.

  13. Macro-Invertebrate Decline in Surface Water Polluted with Imidacloprid

    Science.gov (United States)

    Van Dijk, Tessa C.; Van Staalduinen, Marja A.; Van der Sluijs, Jeroen P.

    2013-01-01

    Imidacloprid is one of the most widely used insecticides in the world. Its concentration in surface water exceeds the water quality norms in many parts of the Netherlands. Several studies have demonstrated harmful effects of this neonicotinoid to a wide range of non-target species. Therefore we expected that surface water pollution with imidacloprid would negatively impact aquatic ecosystems. Availability of extensive monitoring data on the abundance of aquatic macro-invertebrate species, and on imidacloprid concentrations in surface water in the Netherlands enabled us to test this hypothesis. Our regression analysis showed a significant negative relationship (Pmacro-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. PMID:23650513

  14. Faulting and erosion in the Argentine Precordillera during changes in subduction regime: Reconciling bedrock cooling and detrital records

    Science.gov (United States)

    Fosdick, Julie C.; Carrapa, Barbara; Ortíz, Gustavo

    2015-12-01

    The Argentine Precordillera is an archetypal retroarc fold-and-thrust belt that records tectonics associated with changing subduction regimes. The interactions between exhumation and faulting in the Precordillera were investigated using apatite and zircon (U-Th-Sm)/He and apatite fission track thermochronometry from the Precordillera and adjacent geologic domains. Inverse modeling of thermal histories constrains eastward in-sequence rock cooling associated with deformation and erosion from 18 to 2 Ma across the Central Precordillera tracking thrusting during this time. The youngest AHe ages (5-2 Ma) and highest erosion rates are located in the eastern and western extremities of the Precordillera and indicate that recent denudation is concentrated at its structural boundaries. Moreover, synchronous rapid Pliocene cooling of the Frontal Cordillera, Eastern Precordillera, and Sierra del Valle Fértil was coeval with initiation of basement-involved faulting in the foreland. Detrital zircon U-Pb geochronology from the ca. 16-8.1 Ma Bermejo foreland basin strata suggests fluvial connectivity westward beyond the Frontal Cordillera to the Main Cordillera and Coast Range followed by an important shift in sediment provenance at ca. 10 Ma. At this time, we suggest that a substantial decrease in Permo-Triassic igneous sources in the Frontal Cordillera and concurrent increase in recycled zircons signatures of Paleozoic strata are best explained by uplift and erosion of the Precordillera during widening of the thrust-belt. Bedrock thermochronology and modeling indicate a 2-6 Myr lag time between faulting-related cooling in the hinterland and the detrital record of deformation in the foreland basin, suggesting that for tectonically active semi-arid settings, bedrock cooling may be more sensitive to onset of faulting. We suggest that high erosion rates in the Frontal Cordillera and Eastern Precordillera are associated with increased interplate coupling during shallowing of the

  15. Procedures for radioecological studies with marine benthic invertebrates

    International Nuclear Information System (INIS)

    Vilquin, A.; Fowler, S.W.; Renfro, W.C.

    1975-01-01

    Methods for the collection, transportation, and pre-experimental handling are briefly described. In designing radioecological experiments on marine benthic invertebrates it is important to prevent overcrowding and to choose healthy, well-acclimated animals. Feeding of the animals and presence or absence of sediments in the aquaria are critical variables in many experiments. Length of time the experiment is run and interim growth of the experimental animals may result in significant variability in results. The physico-chemical form of the radiotracer is another important experimental variable. (author)

  16. Diversity of marine invertebrates in a thermal effluent

    International Nuclear Information System (INIS)

    Logan, D.T.; Maurer, D.

    1975-01-01

    Invertebrates were collected at four sites in the Indian River and Indian River Bay in Delaware to study the effects of thermal effluents from a steam-generating plant. A list of species of anemones, nemerteans, annelids, molluscs, and crustaceans is presented. Differences in species composition, an increase in relative numbers of a pollution indicator organism, and reduction in species number and in the total number of organisms in the effluent were noted. The period of highest diversity corresponded to that of the lowest numbers of species and individuals and highest effluent temperatures. (U.S.)

  17. Procedures for Radioecological Studies with Marine Benthic Invertebrates

    International Nuclear Information System (INIS)

    Vilquin, A.; Fowler, S.W.; Renfro, W.C.

    1976-01-01

    Methods for the collection transportation, and pre-experimental handling are briefly described. In designing radioecological experiments on marine benthic invertebrates it is important to prevent overcrowding and to choose healthy, well-acclimated animals. Feeding of the animals and presence or absence of sediments in the aquaria are critical variables in many experiments. Length of time the experiment is run and interim growth of the experimental animals may result in significant variability in results. The physico-chemical form of the radiotracer is another important experimental variable. (author)

  18. Recent Advances in Drug Discovery from South African Marine Invertebrates

    Directory of Open Access Journals (Sweden)

    Michael T. Davies-Coleman

    2015-10-01

    Full Text Available Recent developments in marine drug discovery from three South African marine invertebrates, the tube worm Cephalodiscus gilchristi, the ascidian Lissoclinum sp. and the sponge Topsentia pachastrelloides, are presented. Recent reports of the bioactivity and synthesis of the anti-cancer secondary metabolites cephalostatin and mandelalides (from C. gilchristi and Lissoclinum sp., respectively and various analogues are presented. The threat of drug-resistant pathogens, e.g., methicillin-resistant Staphylococcus aureus (MRSA, is assuming greater global significance, and medicinal chemistry strategies to exploit the potent MRSA PK inhibition, first revealed by two marine secondary metabolites, cis-3,4-dihydrohamacanthin B and bromodeoxytopsentin from T. pachastrelloides, are compared.

  19. The Rabbit Stream Cipher

    DEFF Research Database (Denmark)

    Boesgaard, Martin; Vesterager, Mette; Zenner, Erik

    2008-01-01

    The stream cipher Rabbit was first presented at FSE 2003, and no attacks against it have been published until now. With a measured encryption/decryption speed of 3.7 clock cycles per byte on a Pentium III processor, Rabbit does also provide very high performance. This paper gives a concise...... description of the Rabbit design and some of the cryptanalytic results available....

  20. Music Streaming in Denmark

    DEFF Research Database (Denmark)

    Pedersen, Rasmus Rex

    This report analyses how a ’per user’ settlement model differs from the ‘pro rata’ model currently used. The analysis is based on data for all streams by WiMP users in Denmark during August 2013. The analysis has been conducted in collaboration with Christian Schlelein from Koda on the basis of d...

  1. Academic streaming in Europe

    DEFF Research Database (Denmark)

    Falaschi, Alessandro; Mønster, Dan; Doležal, Ivan

    2004-01-01

    The TF-NETCAST task force was active from March 2003 to March 2004, and during this time the mem- bers worked on various aspects of streaming media related to the ultimate goal of setting up common services and infrastructures to enable netcasting of high quality content to the academic community...

  2. Riffle zoobenthos in streams receiving acid mine drainage

    Energy Technology Data Exchange (ETDEWEB)

    Koryak, M; Shapiro, M A; Sykora, J L

    1972-01-01

    The bottom fauna of a stream polluted by acid mine drainage, was studied, using the standard methods of sample collecting. In localities immediately influenced by mine drainage, where very low pH values and high acidities prevail, the effect of acid mine wastes on the ecology and composition of the benthic fauna is, in general, similar to the effect of organic pollution. In these areas we found high numbers of individuals comprised of a few species. In the zones of active neutralization, where iron hydroxides are deposited, species diversity slightly increases but the biomass is very low. The most numerous invertebrates in the stream sections exhibiting high acidity and low pH are midge larvae, especially Tendipes gr. riparius. The number of insect groups present increases steadily with progressive neutralization until crustacea (amphipoda) and oligochaeta appear, indicating considerable improvement in water quality. The supply of desirable benthic fish food (Tendipes ssp.) is very high in the parts of the stream where low pH, high acidity, and high ferrous iron concentrations prevail. Unfortunately, fish cannot survive under these conditions to utilize this abundant food supply. On the other hand, in the less acidic zones, where fish could possibly survive, the deposition of ferric iron drastically diminishes the total biomass of benthic organisms and therefore severely limits fish populations.

  3. Effects of intense agricultural practices on heterotrophic processes in streams

    Energy Technology Data Exchange (ETDEWEB)

    Piscart, Christophe [Universite Claude Bernard Lyon 1 - Laboratoire d' Ecologie des Hydrosystemes Fluviaux - UMR CNRS 5023 - Campus Doua, 43 Bd du 11 Novembre 1918, 69622 Villeurbanne Cedex (France); Universite de Rennes 1 - UMR CNRS ECOBIO 6553 - Campus Beaulieu, 263 Av. du General Leclerc, 35042 Rennes Cedex (France)], E-mail: christophe.piscart@univ-lyon1.fr; Genoel, Romuald [Universite de Rennes 1 - UMR CNRS ECOBIO 6553 - Campus Beaulieu, 263 Av. du General Leclerc, 35042 Rennes Cedex (France); Doledec, Sylvain [Universite Claude Bernard Lyon 1 - Laboratoire d' Ecologie des Hydrosystemes Fluviaux - UMR CNRS 5023 - Campus Doua, 43 Bd du 11 Novembre 1918, 69622 Villeurbanne Cedex (France); Chauvet, Eric [Universite Paul Sabatier de Toulouse - Laboratoire EcoLab - UMR CNRS 5245, 29 rue Jeanne Marvig, 31055 Toulouse Cedex 4 (France); Marmonier, Pierre [Universite Claude Bernard Lyon 1 - Laboratoire d' Ecologie des Hydrosystemes Fluviaux - UMR CNRS 5023 - Campus Doua, 43 Bd du 11 Novembre 1918, 69622 Villeurbanne Cedex (France); Universite de Rennes 1 - UMR CNRS ECOBIO 6553 - Campus Beaulieu, 263 Av. du General Leclerc, 35042 Rennes Cedex (France)

    2009-03-15

    In developed countries, changes in agriculture practices have greatly accelerated the degradation of the landscape and the functioning of adjacent aquatic ecosystems. Such alteration can in turn impair the services provided by aquatic ecosystems, namely the decomposition of organic matter, a key process in most small streams. To study this alteration, we recorded three measures of heterotrophic activity corresponding to microbial hydrolasic activity (FDA hydrolysis) and leaf litter breakdown rates with (k{sub c}) and without invertebrates (k{sub f}) along a gradient of contrasted agricultural pressures. Hydrolasic activity and k{sub f} reflect local/microhabitat conditions (i.e. nutrient concentrations and organic matter content of the sediment) but not land use while k{sub c} reflects land-use conditions. k{sub c}, which is positively correlated with the biomass of Gammaridae, significantly decreased with increasing agricultural pressure, contrary to the taxonomic richness and biomass of Trichoptera and Plecoptera. Gammaridae may thus be considered a key species for organic matter recycling in agriculture-impacted streams. - This study highlights the consequences of intensive agricultural practices on heterotrophic processes in streams along a strong gradient of perturbation.

  4. The zoobenthos communities of streams in the Katon-Karagai State National Natural Park (the Bukhtarma river basin, Kazakhstan

    Directory of Open Access Journals (Sweden)

    Anna A. Evseeva

    2016-08-01

    Full Text Available The article presents the results of a study of zoobenthos in streams in the Katon-Karagay national Park, carried out in 2009–2011. Presented are the taxonomic composition, a description of the spatial distribution of the given habitat classification of the studied small streams, and an area analysis of the fauna of amphibiotic insects of the studied area. An assessment of significance and metrics of zoobenthic communities for biological indication of the ecological status of the streams in the Bukhtarma river basin was carried out. Conducted research on anthropogenic load in unaffected rivers or sections of rivers will solve the problems associated with the lack of baseline data on the basin of the Bukhtarma river. Recommendations are given for the biodiversity conservation of stream bottom invertebrates in Protected Areas in the Altai-Sayan Ecoregion within Kazakhstan.

  5. Lichen physiological traits and growth forms affect communities of associated invertebrates.

    Science.gov (United States)

    Bokhorst, Stef; Asplund, Johan; Kardol, Paul; Wardle, David A

    2015-09-01

    While there has been much interest in the relationships between traits of primary producers and composition of associated invertebrate consumer communities, our knowledge is largely based on studies from vascular plants, while other types of functionally important producers, such as lichens, have rarely been considered. To address how physiological traits of lichens drive community composition of invertebrates, we collected thalli from 27 lichen species from southern Norway and quantified the communities of associated springtails, mites, and nematodes. For each lichen species, we measured key physiological thallus traits and determined whether invertebrate communities were correlated with these traits. We also explored whether invertebrate communities differed among lichen groups, categorized according to nitrogen-fixing ability, growth form, and substratum. Lichen traits explained up to 39% of the variation in abundances of major invertebrate groups. For many invertebrate groups, abundance was positively correlated with lichen N and P concentrations, N:P ratio, and the percentage of water content on saturation (WC), but had few relationships with concentrations of carbon-based secondary compounds. Diversity and taxonomic richness of invertebrate groups were sometimes also correlated with lichen N and N:P ratios. Nitrogen-fixing lichens showed higher abundance and diversity of some invertebrate groups than did non-N-fixing lichens. However, this emerged in part because most N-fixing lichens have a foliose growth form that benefits invertebrates, through, improving the microclimate, independently of N concentration. Furthermore, invertebrate communities associated with terricolous lichens were determined more by their close proximity to the soil invertebrate pool than by lichen traits. Overall, our results reveal that differences between lichen species have a large impact on the invertebrate communities that live among the thalli. Different invertebrate groups show

  6. Antimicrobial peptides in marine invertebrate health and disease.

    Science.gov (United States)

    Destoumieux-Garzón, Delphine; Rosa, Rafael Diego; Schmitt, Paulina; Barreto, Cairé; Vidal-Dupiol, Jeremie; Mitta, Guillaume; Gueguen, Yannick; Bachère, Evelyne

    2016-05-26

    Aquaculture contributes more than one-third of the animal protein from marine sources worldwide. A significant proportion of aquaculture products are derived from marine protostomes that are commonly referred to as 'marine invertebrates'. Among them, penaeid shrimp (Ecdysozosoa, Arthropoda) and bivalve molluscs (Lophotrochozoa, Mollusca) are economically important. Mass rearing of arthropods and molluscs causes problems with pathogens in aquatic ecosystems that are exploited by humans. Remarkably, species of corals (Cnidaria) living in non-exploited ecosystems also suffer from devastating infectious diseases that display intriguing similarities with those affecting farmed animals. Infectious diseases affecting wild and farmed animals that are present in marine environments are predicted to increase in the future. This paper summarizes the role of the main pathogens and their interaction with host immunity, with a specific focus on antimicrobial peptides (AMPs) and pathogen resistance against AMPs. We provide a detailed review of penaeid shrimp AMPs and their role at the interface between the host and its resident/pathogenic microbiota. We also briefly describe the relevance of marine invertebrate AMPs in an applied context.This article is part of the themed issue 'Evolutionary ecology of arthropod antimicrobial peptides'. © 2016 The Author(s).

  7. Soil invertebrate fauna enhances grassland succession and diversity.

    Science.gov (United States)

    De Deyn, Gerlinde B; Raaijmakers, Ciska E; Zoomer, H Rik; Berg, Matty P; de Ruiter, Peter C; Verhoef, Herman A; Bezemer, T Martijn; van der Putten, Wim H

    2003-04-17

    One of the most important areas in ecology is to elucidate the factors that drive succession in ecosystems and thus influence the diversity of species in natural vegetation. Significant mechanisms in this process are known to be resource limitation and the effects of aboveground vertebrate herbivores. More recently, symbiotic and pathogenic soil microbes have been shown to exert a profound effect on the composition of vegetation and changes therein. However, the influence of invertebrate soil fauna on succession has so far received little attention. Here we report that invertebrate soil fauna might enhance both secondary succession and local plant species diversity. Soil fauna from a series of secondary grassland succession stages selectively suppress early successional dominant plant species, thereby enhancing the relative abundance of subordinate species and also that of species from later succession stages. Soil fauna from the mid-succession stage had the strongest effect. Our results clearly show that soil fauna strongly affects the composition of natural vegetation and we suggest that this knowledge might improve the restoration and conservation of plant species diversity.

  8. Toxicity of carbon nanotubes to freshwater aquatic invertebrates

    Science.gov (United States)

    Mwangi, Joseph N.; Wang, Ning; Ingersoll, Christopher G.; Hardesty, Doug K.; Brunson, Eric L.; Li, Hao; Deng, Baolin

    2012-01-01

    Carbon nanotubes (CNTs) are hydrophobic in nature and thus tend to accumulate in sediments if released into aquatic environments. As part of our overall effort to examine the toxicity of carbon-based nanomaterials to sediment-dwelling invertebrates, we have evaluated the toxicity of different types of CNTs in 14-d water-only exposures to an amphipod (Hyalella azteca), a midge (Chironomus dilutus), an oligochaete (Lumbriculus variegatus), and a mussel (Villosa iris) in advance of conducting whole-sediment toxicity tests with CNTs. The results of these toxicity tests conducted with CNTs added to water showed that 1.00g/L (dry wt) of commercial sources of CNTs significantly reduced the survival or growth of the invertebrates. Toxicity was influenced by the type and source of the CNTs, by whether the materials were precleaned by acid, by whether sonication was used to disperse the materials, and by species of the test organisms. Light and electron microscope imaging of the surviving test organisms showed the presence of CNTs in the gut as well as on the outer surface of the test organisms, although no evidence was observed to show penetration of CNTs through cell membranes. The present study demonstrated that both the metals solubilized from CNTs such as nickel and the "metal-free" CNTs contributed to the toxicity.

  9. A comparative study on androgen metabolism in three invertebrate species.

    Science.gov (United States)

    Janer, G; LeBlanc, G A; Porte, C

    2005-09-15

    A comparative approach was taken in this study to evaluate androgen (androstenedione and testosterone) metabolism in three invertebrate species: the gastropod Marisa cornuarietis, the amphipod Hyalella azteca, and the echinoderm Paracentrotus lividus. The existence of 17beta/3beta-hydroxysteroid dehydrogenase (HSD) and 5alpha-reductase catalyzed reactions was demonstrated in all three species. Androstenedione was primarily converted to 5alpha-androstanedione in M. cornuarietis, while it was primarily metabolized to testosterone in P. lividus and H. azteca. In addition, and consistent with vertebrate findings, tissue specific pathways and sexual dimorphism in androgen metabolism were observed. Namely, testosterone was metabolized to dihydrotestosterone in P. lividus gonads (via 5alpha-reductase), and metabolized to 4-androstene-3beta,17beta-diol in the digestive tube (via 3beta-hydroxysteroid dehydrogenase). Furthermore, the synthesis of 17beta-reduced metabolites of androstenedione (testosterone and dihydrotestosterone) was 3- to 4-fold higher in males of M. cornuarietis than in females. Organotin compounds, which have been shown to interfere with some aspects of androgen metabolism, had no major effect on testosterone metabolism in any of the three species. Fenarimol enhanced 5alpha-reductase-mediated catalysis in gonads of P. lividus. Overall, results demonstrate the ubiquity of some androgen biotransformation processes in invertebrates and reveals interphyla differences in androgen metabolic pathways, and different sensitivity of these pathways to some xenobiotics.

  10. Matrotrophy and placentation in invertebrates: a new paradigm.

    Science.gov (United States)

    Ostrovsky, Andrew N; Lidgard, Scott; Gordon, Dennis P; Schwaha, Thomas; Genikhovich, Grigory; Ereskovsky, Alexander V

    2016-08-01

    Matrotrophy, the continuous extra-vitelline supply of nutrients from the parent to the progeny during gestation, is one of the masterpieces of nature, contributing to offspring fitness and often correlated with evolutionary diversification. The most elaborate form of matrotrophy-placentotrophy-is well known for its broad occurrence among vertebrates, but the comparative distribution and structural diversity of matrotrophic expression among invertebrates is wanting. In the first comprehensive analysis of matrotrophy across the animal kingdom, we report that regardless of the degree of expression, it is established or inferred in at least 21 of 34 animal phyla, significantly exceeding previous accounts and changing the old paradigm that these phenomena are infrequent among invertebrates. In 10 phyla, matrotrophy is represented by only one or a few species, whereas in 11 it is either not uncommon or widespread and even pervasive. Among invertebrate phyla, Platyhelminthes, Arthropoda and Bryozoa dominate, with 162, 83 and 53 partly or wholly matrotrophic families, respectively. In comparison, Chordata has more than 220 families that include or consist entirely of matrotrophic species. We analysed the distribution of reproductive patterns among and within invertebrate phyla using recently published molecular phylogenies: matrotrophy has seemingly evolved at least 140 times in all major superclades: Parazoa and Eumetazoa, Radiata and Bilateria, Protostomia and Deuterostomia, Lophotrochozoa and Ecdysozoa. In Cycliophora and some Digenea, it may have evolved twice in the same life cycle. The provisioning of developing young is associated with almost all known types of incubation chambers, with matrotrophic viviparity more widespread (20 phyla) than brooding (10 phyla). In nine phyla, both matrotrophic incubation types are present. Matrotrophy is expressed in five nutritive modes, of which histotrophy and placentotrophy are most prevalent. Oophagy, embryophagy and

  11. Analysis of hydraulic characteristics for stream diversion in small stream

    Energy Technology Data Exchange (ETDEWEB)

    Ahn, Sang-Jin; Jun, Kye-Won [Chungbuk National University, Cheongju(Korea)

    2001-10-31

    This study is the analysis of hydraulic characteristics for stream diversion reach by numerical model test. Through it we can provide the basis data in flood, and in grasping stream flow characteristics. Analysis of hydraulic characteristics in Seoknam stream were implemented by using computer model HEC-RAS(one-dimensional model) and RMA2(two-dimensional finite element model). As a result we became to know that RMA2 to simulate left, main channel, right in stream is more effective method in analysing flow in channel bends, steep slope, complex bed form effect stream flow characteristics, than HEC-RAS. (author). 13 refs., 3 tabs., 5 figs.

  12. Influence of antifouling paint on freshwater invertebrates (Mytilidae, Chironomidae and Naididae): density, richness and composition.

    Science.gov (United States)

    Fujita, D S; Takeda, A M; Coutinho, R; Fernandes, F C

    2015-11-01

    We conducted a study about invertebrates on artificial substrates with different antifouling paints in order to answer the following questions 1) is there lower accumulation of organic matter on substrates with antifouling paints, 2) is invertebrate colonization influenced by the release of biocides from antifouling paints, 3) is the colonization of aquatic invertebrates positively influenced by the material accumulated upon the substrate surface and 4) is the assemblage composition of invertebrates similar among the different antifouling paints? To answer these questions, four structures were installed in the Baía River in February 1st, 2007. Each structure was composed of 7 wood boards: 5 boards painted with each type of antifouling paints (T1, T2, T3, T4 and T5), one painted only with the primer (Pr) and the other without any paint (Cn). After 365 days, we observed a greater accumulation of organic matter in the substrates with T2 and T3 paint coatings. Limnoperna fortunei was recorded in all tested paints, with higher densities in the control, primer, T2 and T3. The colonization of Chironomidae and Naididae on the substrate was positively influenced by L. fortunei density. The non-metric multidimensional scaling (NMDS) of the invertebrate community provided evidence of the clear distinction of invertebrate assemblages among the paints. Paints T2 and T3 were the most similar to the control and primer. Our results suggest that antifouling paints applied on substrates hinder invertebrate colonization by decreasing the density and richness of invertebrates.

  13. Slovakian and Turkish Students' Fear, Disgust and Perceived Danger of Invertebrates

    Science.gov (United States)

    Prokop, Pavol; Usak, Muhammet; Erdogan, Mehmet; Fancovicova, Jana; Bahar, Mehmet

    2011-01-01

    Human perceives invertebrates less positively than vertebrates because they are small and behaviourally and morphologically unfamiliar. This cross-cultural research focused on Slovakian (n=150) and Turkish (n=164) students' fear, disgust and perceived danger regarding 25 invertebrates [including 5 disease relevant adult insects, 5 ectoparasites, 5…

  14. Great cormorants reveal overlooked secondary dispersal of plants and invertebrates by piscivorous waterbirds

    NARCIS (Netherlands)

    van Leeuwen, C.H.A.; Lovas-Kiss, A.; Ovegård, M.; Green, Andy J.

    2017-01-01

    In wetland ecosystems, birds and fish are important dispersal vectors for plants and invertebrates, but the consequences of their interactions as vectors are unknown. Darwin suggested that piscivorous birds carry out secondary dispersal of seeds and invertebrates via predation on fish. We tested

  15. Aboveground vertebrate and invertebrate herbivore impacts on net N mineralization in subalpine grasslands

    Science.gov (United States)

    Anita C. Risch; Martin Schutz; Martijn L. Vandegehuchte; Wim H. van der Putten; Henk Duyts; Ursina Raschein; Dariusz J. Gwiazdowicz; Matt D. Busse; Deborah S. Page-Dumroese; Stephan Zimmerman

    2015-01-01

    Aboveground herbivores have strong effects on grassland nitrogen (N) cycling. They can accelerate or slow down soil net N mineralization depending on ecosystem productivity and grazing intensity. Yet, most studies only consider either ungulates or invertebrate herbivores, but not the combined effect of several functionally different vertebrate and invertebrate...

  16. 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.

  17. Quantifying spatial scaling patterns and their local and regional correlates in headwater streams: implications for resilience

    Directory of Open Access Journals (Sweden)

    Emma Göthe

    2014-09-01

    Full Text Available The distribution of functional traits within and across spatiotemporal scales has been used to quantify and infer the relative resilience across ecosystems. We use explicit spatial modeling to evaluate within- and cross-scale redundancy in headwater streams, an ecosystem type with a hierarchical and dendritic network structure. We assessed the cross-scale distribution of functional feeding groups of benthic invertebrates in Swedish headwater streams during two seasons. We evaluated functional metrics, i.e., Shannon diversity, richness, and evenness, and the degree of redundancy within and across modeled spatial scales for individual feeding groups. We also estimated the correlates of environmental versus spatial factors of both functional composition and the taxonomic composition of functional groups for each spatial scale identified. Measures of functional diversity and within-scale redundancy of functions were similar during both seasons, but both within- and cross-scale redundancy were low. This apparent low redundancy was partly attributable to a few dominant taxa explaining the spatial models. However, rare taxa with stochastic spatial distributions might provide additional information and should therefore be considered explicitly for complementing future resilience assessments. Otherwise, resilience may be underestimated. Finally, both environmental and spatial factors correlated with the scale-specific functional and taxonomic composition. This finding suggests that resilience in stream networks emerges as a function of not only local conditions but also regional factors such as habitat connectivity and invertebrate dispersal.

  18. Quantifying spatial scaling patterns and their local and regional correlates in headwater streams: Implications for resilience

    Science.gov (United States)

    Gothe, Emma; Sandin, Leonard; Allen, Craig R.; Angeler, David G.

    2014-01-01

    The distribution of functional traits within and across spatiotemporal scales has been used to quantify and infer the relative resilience across ecosystems. We use explicit spatial modeling to evaluate within- and cross-scale redundancy in headwater streams, an ecosystem type with a hierarchical and dendritic network structure. We assessed the cross-scale distribution of functional feeding groups of benthic invertebrates in Swedish headwater streams during two seasons. We evaluated functional metrics, i.e., Shannon diversity, richness, and evenness, and the degree of redundancy within and across modeled spatial scales for individual feeding groups. We also estimated the correlates of environmental versus spatial factors of both functional composition and the taxonomic composition of functional groups for each spatial scale identified. Measures of functional diversity and within-scale redundancy of functions were similar during both seasons, but both within- and cross-scale redundancy were low. This apparent low redundancy was partly attributable to a few dominant taxa explaining the spatial models. However, rare taxa with stochastic spatial distributions might provide additional information and should therefore be considered explicitly for complementing future resilience assessments. Otherwise, resilience may be underestimated. Finally, both environmental and spatial factors correlated with the scale-specific functional and taxonomic composition. This finding suggests that resilience in stream networks emerges as a function of not only local conditions but also regional factors such as habitat connectivity and invertebrate dispersal.

  19. In situ effects of simulated overfishing and eutrophication on settlement of benthic coral reef invertebrates in the Central Red Sea.

    KAUST Repository

    Jessen, Christian; Voolstra, Christian R.; Wild, Christian

    2014-01-01

    overfishing through predator/grazer exclusion and simulated eutrophication through fertilizer addition on settlement of reef associated invertebrates on light-exposed and -shaded tiles over 4 months. At the end of the study period invertebrates had almost

  20. NODC Standard Format Pathology Data Sets (1973-1980): Marine Invertebrate Pathology (F063) (NODC Accession 0014191)

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — Marine Invertebrate Pathology (F063) contains data from examinations of diseased marine invertebrates. Although these data maybe from field observations, they derive...

  1. Streaming gravity mode instability

    International Nuclear Information System (INIS)

    Wang Shui.

    1989-05-01

    In this paper, we study the stability of a current sheet with a sheared flow in a gravitational field which is perpendicular to the magnetic field and plasma flow. This mixing mode caused by a combined role of the sheared flow and gravity is named the streaming gravity mode instability. The conditions of this mode instability are discussed for an ideal four-layer model in the incompressible limit. (author). 5 refs

  2. Autonomous Byte Stream Randomizer

    Science.gov (United States)

    Paloulian, George K.; Woo, Simon S.; Chow, Edward T.

    2013-01-01

    Net-centric networking environments are often faced with limited resources and must utilize bandwidth as efficiently as possible. In networking environments that span wide areas, the data transmission has to be efficient without any redundant or exuberant metadata. The Autonomous Byte Stream Randomizer software provides an extra level of security on top of existing data encryption methods. Randomizing the data s byte stream adds an extra layer to existing data protection methods, thus making it harder for an attacker to decrypt protected data. Based on a generated crypto-graphically secure random seed, a random sequence of numbers is used to intelligently and efficiently swap the organization of bytes in data using the unbiased and memory-efficient in-place Fisher-Yates shuffle method. Swapping bytes and reorganizing the crucial structure of the byte data renders the data file unreadable and leaves the data in a deconstructed state. This deconstruction adds an extra level of security requiring the byte stream to be reconstructed with the random seed in order to be readable. Once the data byte stream has been randomized, the software enables the data to be distributed to N nodes in an environment. Each piece of the data in randomized and distributed form is a separate entity unreadable on its own right, but when combined with all N pieces, is able to be reconstructed back to one. Reconstruction requires possession of the key used for randomizing the bytes, leading to the generation of the same cryptographically secure random sequence of numbers used to randomize the data. This software is a cornerstone capability possessing the ability to generate the same cryptographically secure sequence on different machines and time intervals, thus allowing this software to be used more heavily in net-centric environments where data transfer bandwidth is limited.

  3. An invertebrate stomach's view on vertebrate ecology: certain invertebrates could be used as "vertebrate samplers" and deliver DNA-based information on many aspects of vertebrate ecology.

    Science.gov (United States)

    Calvignac-Spencer, Sébastien; Leendertz, Fabian H; Gilbert, M Thomas P; Schubert, Grit

    2013-11-01

    Recent studies suggest that vertebrate genetic material ingested by invertebrates (iDNA) can be used to investigate vertebrate ecology. Given the ubiquity of invertebrates that feed on vertebrates across the globe, iDNA might qualify as a very powerful tool for 21st century population and conservation biologists. Here, we identify some invertebrate characteristics that will likely influence iDNA retrieval and elaborate on the potential uses of invertebrate-derived information. We hypothesize that beyond inventorying local faunal diversity, iDNA should allow for more profound insights into wildlife population density, size, mortality, and infectious agents. Based on the similarities of iDNA with other low-quality sources of DNA, a general technical framework for iDNA analyses is proposed. As it is likely that no such thing as a single ideal iDNA sampler exists, forthcoming research efforts should aim at cataloguing invertebrate properties relevant to iDNA retrieval so as to guide future usage of the invertebrate tool box. © 2013 WILEY Periodicals, Inc.

  4. The LHCb Turbo stream

    Energy Technology Data Exchange (ETDEWEB)

    Puig, A., E-mail: albert.puig@cern.ch

    2016-07-11

    The LHCb experiment will record an unprecedented dataset of beauty and charm hadron decays during Run II of the LHC, set to take place between 2015 and 2018. A key computing challenge is to store and process this data, which limits the maximum output rate of the LHCb trigger. So far, LHCb has written out a few kHz of events containing the full raw sub-detector data, which are passed through a full offline event reconstruction before being considered for physics analysis. Charm physics in particular is limited by trigger output rate constraints. A new streaming strategy includes the possibility to perform the physics analysis with candidates reconstructed in the trigger, thus bypassing the offline reconstruction. In the Turbo stream the trigger will write out a compact summary of physics objects containing all information necessary for analyses. This will allow an increased output rate and thus higher average efficiencies and smaller selection biases. This idea will be commissioned and developed during 2015 with a selection of physics analyses. It is anticipated that the turbo stream will be adopted by an increasing number of analyses during the remainder of LHC Run II (2015–2018) and ultimately in Run III (starting in 2020) with the upgraded LHCb detector.

  5. Functional traits of soil invertebrates as indicators for exposure to soil disturbance.

    Science.gov (United States)

    Hedde, Mickaël; van Oort, Folkert; Lamy, Isabelle

    2012-05-01

    We tested a trait-based approach to link a soil disturbance to changes in invertebrate communities. Soils and macro-invertebrates were sampled in sandy soils contaminated by long-term wastewater irrigation, adding notably organic matter and trace metals (TM). We hypothesized that functional traits of invertebrates depict ways of exposure and that exposure routes relate to specific TM pools. Geophages and soft-body invertebrates were chosen to inform on exposure by ingestion or contact, respectively. Trait-based indices depicted more accurately effects of pollution than community density and diversity did. Exposure by ingestion had more deleterious effects than by contact. Both types of exposed invertebrates were influenced by TM, but geophages mainly responded to changes in soil organic matter contents. The trait-based approach requires to be applied in various conditions to uncorrelate specific TM impacts from those of other environmental factors. Copyright © 2012 Elsevier Ltd. All rights reserved.

  6. Ecotoxicity of engineered nanoparticles to aquatic invertebrates: a brief review and recommendations for future toxicity testing

    DEFF Research Database (Denmark)

    Baun, Anders; Hartmann, Nanna Isabella Bloch; Grieger, Khara Deanne

    2008-01-01

    Based on a literature review and an overview of toxic effects of engineered nanoparticles in aquatic invertebrates, this paper proposes a number of recommendations for the developing field of nanoecotoxicology by highlighting the importance of invertebrates as sensitive and relevant test organisms...... through standardized short-term (lethality) tests with invertebrates as a basis for investigating behaviour and bioavailability of engineered nanoparticles in the aquatic environment. Based on this literature review, we further recommend that research is directed towards invertebrate tests employing long....... Results show that there is a pronounced lack of data in this field (less than 20 peer-reviewed papers are published so far), and the most frequently tested engineered nanoparticles in invertebrate tests are C-60, carbon nanotubes, and titanium dioxide. In addition, the majority of the studies have used...

  7. A study of radionuclide transfer between invertebrates and their marine sedimentary environment

    International Nuclear Information System (INIS)

    Amiard-Triquet, Claude.

    1975-11-01

    Exchanges between sediment and marine organisms were studied in some benthic marine invertebrates, especially Arenicola marina L. (an Annelid). Experiments were carried out on the transfer of 60 Co, 137 Cs and accessorily 59 Fe and 144 Ce. Water was the chief vector for benthic marine invertebrates. These invertebrates seemed to act mainly in sedimentary areas on the redistribution of adsorbed radionuclides within the sediment. Radioactive contamination of the invertebrates was affected by various physiological or ecological factors. Benthic marine invertebrates were then studied as links in food chains. The transfer of 60 Co was studied in three food chains or fractions of food chains. The procedure allowed interesting observations from the health protection point of view and more fundamental investigations on cobalt metabolism (regulation, excretion) in a mollusc, a crustacea and a teleost [fr

  8. Re-Meandering of Lowland Streams

    DEFF Research Database (Denmark)

    Pedersen, Morten Lauge; Kristensen, Klaus Kevin; Friberg, Nikolai

    2014-01-01

    We evaluated the restoration of physical habitats and its influence on macroinvertebrate community structure in 18 Danish lowland streams comprising six restored streams, six streams with little physical alteration and six channelized streams. We hypothesized that physical habitats and macroinver...

  9. Stream processing health card application.

    Science.gov (United States)

    Polat, Seda; Gündem, Taflan Imre

    2012-10-01

    In this paper, we propose a data stream management system embedded to a smart card for handling and storing user specific summaries of streaming data coming from medical sensor measurements and/or other medical measurements. The data stream management system that we propose for a health card can handle the stream data rates of commonly known medical devices and sensors. It incorporates a type of context awareness feature that acts according to user specific information. The proposed system is cheap and provides security for private data by enhancing the capabilities of smart health cards. The stream data management system is tested on a real smart card using both synthetic and real data.

  10. Mercury cycling in stream ecosystems. 3. Trophic dynamics and methylmercury bioaccumulation

    Science.gov (United States)

    Chasar, L.C.; Scudder, B.C.; Stewart, A.R.; Bell, A.H.; Aiken, G.R.

    2009-01-01

    Trophic dynamics (community composition and feeding relationships) have been identified as important drivers of methylmercury (MeHg) bioaccumulation in lakes, reservoirs, and marine ecosystems. The relative importance of trophic dynamics and geochemical controls on MeHg bioaccumulation in streams, however, remains poorly characterized. MeHg bioaccumulation was evaluated in eight stream ecosystems across the United States (Oregon, Wisconsin, and Florida) spanning large ranges in climate, landscape characteristics, atmospheric Hg deposition, and stream chemistry. Across all geographic regions and all streams, concentrations of total Hg (THg) in top predator fish and forage fish, and MeHg in invertebrates, were strongly positively correlated to concentrations of filtered THg (FTHg), filtered MeHg (FMeHg), and dissolved organic carbon (DOC); to DOC complexity (as measured by specific ultraviolet absorbance); and to percent wetland in the stream basins. Correlations were strongest for nonurban streams. Although regressions of log[Hg] versus ??15N indicate that Hg in biota increased significantly with increasing trophic position within seven of eight individual streams, Hg concentrations in top predator fish (including cutthroat, rainbow, and brown trout; green sunfish; and largemouth bass) were not strongly influenced by differences in relative trophic position. Slopes of log[Hg] versus ??15N, an indicator of the efficiency of trophic enrichment, ranged from 0.14 to 0.27 for all streams. These data suggest that, across the large ranges in FTHg (0.14-14.2 ng L-1), FMeHg (0.023-1.03 ng L-1), and DOC (0.50-61.0 mg L-1) found in this study, Hg contamination in top predator fish in streams likely is dominated by the amount of MeHg available for uptake at the base of the food web rather than by differences in the trophic position of top predator fish. ?? 2009 American Chemical Society.

  11. Leaf degradation of Salix humboldtiana Willd: (Salicaceae and invertebrate colonization in a subtropical lake (Brazil Degradação foliar de Salix humboldtiana Willd: (Salicaceae e colonização por invertebrados em um lago subtropical (Brasil

    Directory of Open Access Journals (Sweden)

    Franko Telöken

    2011-03-01

    Full Text Available AIM: To evaluate leaf degradation and invertebrate colonization of Salix humboldtiana Willd. in a subtropical shallow lake on the coastal plain of Rio Grande do Sul, Brazil; METHODS: Litter bags containing 6.85 g of leaves were incubated in the superficial layer of sediment in the littoral region for 1, 4, 7, 14, 32, 47 and 71 days; RESULTS: After 71 days, a loss of 51% of the initial leaf weight was observed (k = 0.0100 d-1. We estimated that it would take 300 days to lose 95% of the initial weight. A total of 16040 organisms and 35 taxa were identified. Caenidae (25.9%, Oligochaeta (19%, Ostracoda (13.8%, Hydracarina (9.8%, Tanypodinae (9.7% and Coenagrionidae (7.7% were the most highly represented taxa. We observed increases in density, richness and diversity of taxa over time, with a stabilizing trend noted in the taxa diversity. Regarding the functional trophic groups (FTGs, gathering-collectors accounted for 57.6% of the community, while predators (25%, scrapers (15.8%, filtering-collectors (0.88% and shredders (0.73% were also represented. The diversity and evenness of the FTGs had stabilized by day 14; CONCLUSIONS: S. humboldtiana detritus provides a favorable habitat for a sufficient duration to support a high density and diversity of aquatic invertebrates. The small percentage of shredders indicates the minor influence of the invertebrate community on the rate of detrital degradation. The main contribution of invertebrates to detrital processing comes from the consumption of fine particulate organic matter by gathering-collectors.OBJETIVOS: Avaliar a degradação foliar de Salix humboldtiana Willd. e a colonização pela comunidade de invertebrados aquáticos em um lago raso subtropical, planície costeira do Rio Grande do Sul, Brasil; MÉTODOS: Bolsas de decomposição contendo 6,85 g de folhas foram incubadas na região litorânea, na superfície do sedimento, e retiradas após 1, 4, 7, 14, 32, 47 e 71 dias de decomposi

  12. Evolutionary Transition of Promoter and Gene Body DNA Methylation across Invertebrate-Vertebrate Boundary.

    Science.gov (United States)

    Keller, Thomas E; Han, Priscilla; Yi, Soojin V

    2016-04-01

    Genomes of invertebrates and vertebrates exhibit highly divergent patterns of DNA methylation. Invertebrate genomes tend to be sparsely methylated, and DNA methylation is mostly targeted to a subset of transcription units (gene bodies). In a drastic contrast, vertebrate genomes are generally globally and heavily methylated, punctuated by the limited local hypo-methylation of putative regulatory regions such as promoters. These genomic differences also translate into functional differences in DNA methylation and gene regulation. Although promoter DNA methylation is an important regulatory component of vertebrate gene expression, its role in invertebrate gene regulation has been little explored. Instead, gene body DNA methylation is associated with expression of invertebrate genes. However, the evolutionary steps leading to the differentiation of invertebrate and vertebrate genomic DNA methylation remain unresolved. Here we analyzed experimentally determined DNA methylation maps of several species across the invertebrate-vertebrate boundary, to elucidate how vertebrate gene methylation has evolved. We show that, in contrast to the prevailing idea, a substantial number of promoters in an invertebrate basal chordate Ciona intestinalis are methylated. Moreover, gene expression data indicate significant, epigenomic context-dependent associations between promoter methylation and expression in C. intestinalis. However, there is no evidence that promoter methylation in invertebrate chordate has been evolutionarily maintained across the invertebrate-vertebrate boundary. Rather, body-methylated invertebrate genes preferentially obtain hypo-methylated promoters among vertebrates. Conversely, promoter methylation is preferentially found in lineage- and tissue-specific vertebrate genes. These results provide important insights into the evolutionary origin of epigenetic regulation of vertebrate gene expression. © The Author(s) 2015. Published by Oxford University Press on behalf

  13. Environmental hazards of aluminum to plants, invertebrates, fish, and wildlife

    Science.gov (United States)

    Sparling, D.W.; Lowe, T.P.

    1996-01-01

    Aluminum is extremely common throughout the world and is innocuous under circumneutral or alkaline conditions. However, in acidic environments, it can be a maJor limiting factor to many plants and aquatic organisms. The greatest concern for toxicity in North America occurs in areas that are affected by wet and dry acid deposition, such as eastern Canada and the northeastern U.S. Acid mine drainage, logging, and water treatment plant effluents containing alum can be other maJor sources of Al. In solution, the metal can combine with several different agents to affect toxicity. In general, Al hydroxides and monomeric Al are the most toxic forms. Dissolved organic carbons, F, PO(3)3- and SO(4)2- ameliorate toxicity by reducing bioavailability. Elevated metal levels in water and soil can cause serious problems for some plants. Algae tend to be both acid- and Al tolerant and, although some species may disappear with reduced pH, overall algae productivity and biomass are seldom affected if pH is above 3.0. Aluminum and acid toxicity tend to be additive to some algae when pH is less than 4.5. Because the metal binds with inorganic P, it may reduce P availability and reduce productivity. Forest die-backs in North America involving red spruce, Fraser fir, balsam fir, loblolly pine, slash pine, and sugar maples have been ascribed to Al toxicity, and extensive areas of European forests have died because of the combination of high soil Al and low pH. Extensive research on crops has produced Al-resistant cultivars and considerable knowledge about mechanisms of and defenses against toxicity. Very low Al levels may benefit some plants, although the metal is not recognized as an essential nutrient. Hyperaccumulator species of plants may concentrate Al to levels that are toxic to herbivores. Toxicity in aquatic invertebrates is also acid dependent. Taxa such as Ephemeroptera, Plecoptera, and Cladocera are sensitive and may perish when Al is less than 1 mg.L-1 whereas dipterans

  14. DMPD: Infectious non-self recognition in invertebrates: lessons from Drosophila andother insect models. [Dynamic Macrophage Pathway CSML Database

    Lifescience Database Archive (English)

    Full Text Available 15476918 Infectious non-self recognition in invertebrates: lessons from Drosophila ...fectious non-self recognition in invertebrates: lessons from Drosophila andother insect models. PubmedID 154...76918 Title Infectious non-self recognition in invertebrates: lessons from Drosop

  15. 78 FR 14503 - Amendment 4 to the Corals and Reef Associated Plants and Invertebrates Fishery Management Plan of...

    Science.gov (United States)

    2013-03-06

    .... 120718255-3038-01] RIN 0648-BC38 Amendment 4 to the Corals and Reef Associated Plants and Invertebrates... Fishery Management Plan (FMP) for Corals and Reef Associated Plants and Invertebrates of Puerto Rico and... the coral reef resources FMU to include a vast array of plants and invertebrates that provide habitats...

  16. Distribution of oligochaetes in a stream in the Atlantic Forest in southeastern Brazil

    Directory of Open Access Journals (Sweden)

    BFJV. Rosa

    Full Text Available The oligochaetes are considered good indicators of ecological conditions and specific types of habitats. Among the factors that influence the distribution of these invertebrates are the water flow and the nature of the substrate. The aim of this study is to describe the composition and distribution of oligochaete species in a first-order stream in Atlantic Forest and try to identify if some species are associated with characteristics of particular types of habitats. In the dry season and in the rainy season, sand and litter samples in two riffle areas and two pool areas were collected in different parts along the stream using a hand net. The greatest observed richness and abundance occurred in sand in the pool, however the greatest estimated richness was obtained for litter in the pool. The Kruskal-Wallis analysis showed effect of the different types of habitat on the abundance and richness of oligochaetes. The Nonmetric Multidimensional Scaling (NMDS and Multiresponse Permutation Procedure analysis (MRPP indicated that the variation in the fauna composition had relation with different types of substrates. The indicator species analysis showed that Limnodrilus. hoffmeisteri was an indicator species in both the riffle sand and pool sand and Pristina americana was only an indicator in the pool sand. The high organic matter content in both sandy habitats probably favored the greater abundance of oligochaetes. The results showed that the substrate constitutes an important factor for the local distribution of these invertebrates in streams. The variation of the community structure among mesohabitats and the presence of indicator species of specific types of habitats in the stream demonstrate the importance of environmental heterogeneity for the oligochaetes fauna in forested streams.

  17. Distribution of oligochaetes in a stream in the Atlantic Forest in southeastern Brazil.

    Science.gov (United States)

    Rosa, B F J V; Martins, R T; Alves, R G

    2015-01-01

    The oligochaetes are considered good indicators of ecological conditions and specific types of habitats. Among the factors that influence the distribution of these invertebrates are the water flow and the nature of the substrate. The aim of this study is to describe the composition and distribution of oligochaete species in a first-order stream in Atlantic Forest and try to identify if some species are associated with characteristics of particular types of habitats. In the dry season and in the rainy season, sand and litter samples in two riffle areas and two pool areas were collected in different parts along the stream using a hand net. The greatest observed richness and abundance occurred in sand in the pool, however the greatest estimated richness was obtained for litter in the pool. The Kruskal-Wallis analysis showed effect of the different types of habitat on the abundance and richness of oligochaetes. The Nonmetric Multidimensional Scaling (NMDS) and Multiresponse Permutation Procedure analysis (MRPP) indicated that the variation in the fauna composition had relation with different types of substrates. The indicator species analysis showed that Limnodrilus. hoffmeisteri was an indicator species in both the riffle sand and pool sand and Pristina americana was only an indicator in the pool sand. The high organic matter content in both sandy habitats probably favored the greater abundance of oligochaetes. The results showed that the substrate constitutes an important factor for the local distribution of these invertebrates in streams. The variation of the community structure among mesohabitats and the presence of indicator species of specific types of habitats in the stream demonstrate the importance of environmental heterogeneity for the oligochaetes fauna in forested streams.

  18. Detrital zircon U-Pb geochronology of Cambrian to Triassic miogeoclinal and eugeoclinal strata of Sonora, Mexico

    Science.gov (United States)

    Gehrels, G.E.; Stewart, John H.

    1998-01-01

    One hundred and eighty two individual detrital zircon grains from Cambrian through Permian miogeoclinal strata, Ordovician eugeoclinal rocks, and Triassic post-orogenic sediments in northwestern Sonora have been analyzed. During Cambrian, Devonian, Permian, and Triassic time, most zircons accumulating along this part of the Cordilleran margin were shed from 1.40-1.45 and 1.62-1.78 Ga igneous rocks that are widespread in the southwestern United States and northwestern Mexico. Zircons with ages of approximately 1.11 Ga are common in Cambrian strata and were apparently shed from granite bodies near the sample site. The sources of 225-280 Ma zircons in our Triassic sample are more problematic, as few igneous rocks of these ages are recognized in northwestern Mexico. Such sources may be present but unrecognized, or the grains could have been derived from igneous rocks of the appropriate ages to the northwest in the Mojave Desert region, to the east in Chihuahua and Coahuila, or to the south in accreted(?) arc-type terranes. Because the zircon grains in our Cambrian and Devonian to Triassic samples could have accumulated in proximity to basement rocks near their present position or in the Death Valley region of southern California, our data do not support or refute the existence of the Mojave-Sonora megashear. Ordovician strata of both miogeoclinal and eugeoclinal affinity are dominated by >1.77 Ga detrital zircons, which are considerably older than most basement rocks in the region. Zircon grains in the miogeoclinal sample were apparently derived from the Peace River arch area of northwestern Canada and transported southward by longshore currents. The eugeoclinal grains may also have come from the Peace River arch region, with southward transport by either sedimentary or tectonic processes, or they may have been shed from off-shelf slivers of continents (perhaps Antarctica?) removed from the Cordilleran margin during Neoproterozoic rifting. It is also possible that the

  19. Sensitivity ranking for freshwater invertebrates towards hydrocarbon contaminants.

    Science.gov (United States)

    Gerner, Nadine V; Cailleaud, Kevin; Bassères, Anne; Liess, Matthias; Beketov, Mikhail A

    2017-11-01

    Hydrocarbons have an utmost economical importance but may also cause substantial ecological impacts due to accidents or inadequate transportation and use. Currently, freshwater biomonitoring methods lack an indicator that can unequivocally reflect the impacts caused by hydrocarbons while being independent from effects of other stressors. The aim of the present study was to develop a sensitivity ranking for freshwater invertebrates towards hydrocarbon contaminants, which can be used in hydrocarbon-specific bioindicators. We employed the Relative Sensitivity method and developed the sensitivity ranking S hydrocarbons based on literature ecotoxicological data supplemented with rapid and mesocosm test results. A first validation of the sensitivity ranking based on an earlier field study has been conducted and revealed the S hydrocarbons ranking to be promising for application in sensitivity based indicators. Thus, the first results indicate that the ranking can serve as the core component of future hydrocarbon-specific and sensitivity trait based bioindicators.

  20. The structure and host entry of an invertebrate parvovirus.

    Science.gov (United States)

    Meng, Geng; Zhang, Xinzheng; Plevka, Pavel; Yu, Qian; Tijssen, Peter; Rossmann, Michael G

    2013-12-01

    The 3.5-Å resolution X-ray crystal structure of mature cricket parvovirus (Acheta domesticus densovirus [AdDNV]) has been determined. Structural comparisons show that vertebrate and invertebrate parvoviruses have evolved independently, although there are common structural features among all parvovirus capsid proteins. It was shown that raising the temperature of the AdDNV particles caused a loss of their genomes. The structure of these emptied particles was determined by cryo-electron microscopy to 5.5-Å resolution, and the capsid structure was found to be the same as that for the full, mature virus except for the absence of the three ordered nucleotides observed in the crystal structure. The viral protein 1 (VP1) amino termini could be externalized without significant damage to the capsid. In vitro, this externalization of the VP1 amino termini is accompanied by the release of the viral genome.

  1. Interdependence of specialization and biodiversity in Phanerozoic marine invertebrates.

    Science.gov (United States)

    Nürnberg, Sabine; Aberhan, Martin

    2015-03-17

    Studies of the dynamics of biodiversity often suggest that diversity has upper limits, but the complex interplay between ecological and evolutionary processes and the relative role of biotic and abiotic factors that set upper limits to diversity are poorly understood. Here we statistically assess the relationship between global biodiversity and the degree of habitat specialization of benthic marine invertebrates over the Phanerozoic eon. We show that variation in habitat specialization correlates positively with changes in global diversity, that is, times of high diversity coincide with more specialized faunas. We identify the diversity dynamics of specialists but not generalists, and origination rates but not extinction rates, as the main drivers of this ecological interdependence. Abiotic factors fail to show any significant relationship with specialization. Our findings suggest that the overall level of specialization and its fluctuations over evolutionary timescales are controlled by diversity-dependent processes--driven by interactions between organisms competing for finite resources.

  2. Impact Theory of Mass Extinctions and the Invertebrate Fossil Record

    Science.gov (United States)

    Alvarez, Walter; Kauffman, Erle G.; Surlyk, Finn; Alvarez, Luis W.; Asaro, Frank; Michel, Helen V.

    1984-03-01

    There is much evidence that the Cretaceous-Tertiary boundary was marked by a massive meteorite impact. Theoretical consideration of the consequences of such an impact predicts sharp extinctions in many groups of animals precisely at the boundary. Paleontological data clearly show gradual declines in diversity over the last 1 to 10 million years in various invertebrate groups. Reexamination of data from careful studies of the best sections shows that, in addition to undergoing the decline, four groups (ammonites, cheilostomate bryozoans, brachiopods, and bivalves) were affected by sudden truncations precisely at the iridium anomaly that marks the boundary. The paleontological record thus bears witness to terminal-Cretaceous extinctions on two time scales: a slow decline unrelated to the impact and a sharp truncation synchronous with and probably caused by the impact.

  3. Uptake and depuration of pharmaceuticals in aquatic invertebrates

    International Nuclear Information System (INIS)

    Meredith-Williams, Melanie; Carter, Laura J.; Fussell, Richard; Raffaelli, David; Ashauer, Roman; Boxall, Alistair B.A.

    2012-01-01

    The uptake and depuration of a range of pharmaceuticals in the freshwater shrimp (Gammarus pulex) and the water boatman (Notonecta glauca) was studied. For one compound, studies were also done using the freshwater snail Planobarius corneus. In G. pulex, bioconcentration factors (BCFs) ranged from 4.6 to 185,900 and increased in the order moclobemide < 5-fluoruracil < carbamazepine < diazepam < carvedilol < fluoxetine. In N. glauca BCFs ranged from 0.1 to 1.6 and increased in the order 5-fluorouracil < carbamazepine < moclobemide < diazepam < fluoxetine < carvedilol. For P. corneus, the BCF for carvedilol was 57.3. The differences in degree of uptake across the three organisms may be due to differences in mode of respiration, behaviour and the pH of the test system. BCFs of the pharmaceuticals for each organism were correlated to the pH-corrected liposome–water partition coefficient of the pharmaceuticals. - Highlights: ► One of the first studies exploring the uptake of pharmaceuticals into aquatic invertebrates. ► Data presented on uptake, depuration rates and bioconcentration for a range of pharmaceuticals. ► Uptake is correlated with the pH-corrected liposome–water partition coefficient. ► Findings can be used to better predict impacts of pharmaceuticals on the aquatic environment. - The factors affecting the degree of uptake of pharmaceuticals into aquatic invertebrates were studied. The results indicate that species traits such as respiration and behaviour of the organisms and pH-corrected liposome–water partition coefficients are important factors in determining pharmaceutical uptake.

  4. Comparative ecotoxicity of chlorantraniliprole to non-target soil invertebrates.

    Science.gov (United States)

    Lavtižar, Vesna; Berggren, Kristina; Trebše, Polonca; Kraak, Michiel H S; Verweij, Rudo A; van Gestel, Cornelis A M

    2016-09-01

    The insecticide chlorantraniliprole (CAP) is gaining importance in agricultural practice, but data on its possible negative effects on non-target organisms is severely deficient. This study therefore determined CAP toxicity to non-target soil invertebrates playing a crucial role in ecosystem functioning, including springtails (Folsomia candida), isopods (Porcellio scaber), enchytraeids (Enchytraeus crypticus) and oribatid mites (Oppia nitens). In sublethal toxicity tests in Lufa 2.2 soil, chronic exposure to CAP concentrations up to 1000 mg/kgdw did not affect the survival and reproduction of E. crypticus and O. nitens nor the survival, body weight and consumption of P. scaber. In contrast, the survival and reproduction of F. candida was severely affected, with an EC50 for effects on reproduction of 0.14 mg CAP/kgdw. The toxicity of CAP to the reproduction of F. candida was tested in four different soils following OECD guideline 232, and additionally in an avoidance test according to ISO guideline 17512-2. A significantly lower toxicity in soils rich in organic matter was observed, compared to low organic soils. Observations in the avoidance test with F. candida suggest that CAP acted in a prompt way, by affecting collembolan locomotor abilities thus preventing them from escaping contaminated soil. This study shows that CAP may especially pose a risk to non-target soil arthropods closely related to insects, while other soil invertebrates seem rather insensitive. Copyright © 2016 Elsevier Ltd. All rights reserved.

  5. Bugs, bees and spiders : green roof design for rare invertebrates

    Energy Technology Data Exchange (ETDEWEB)

    Gedge, D. [Livingroofs.org, London (United Kingdom); Kadas, G. [Royal Holloway Univ. of London, London (United Kingdom)

    2004-07-01

    The use of green roofs as mitigation technique for biodiversity is particularly relevant for the objectives of the London Biodiversity Partnership, particularly since London is undergoing large-scale regeneration and many of the new developments will be targeted on brownfield land. In 2002 two research projects were undertaken to create a baseline of data on how invertebrates were using the current green roofs in London. The London Biodiversity Partnership's Black Redstart Action Plan conducts research into green roofs to demonstrate how they can be maximized for biodiversity. The Black Redstart Project ensures that green roofs are used in new developments in London where such developments threaten this species. It is one of the country's rarest breeding birds, and is unique in that it is predominantly found in cities, on brownfield sites and post-industrial sites. Three green roof laboratories were established at 2 sites in London to investigate how substrates, substrate depths and planting affects the fauna associated with brownfields and green roofs in London. Although conservationists in London have urged many developers to provide green roofs to help the Black Redstart, there is concern that many of these roofs do no provide the proper support for the species. In some cases roofs are constructed of commercially driven products such as sedum mats that do provide habitat for some rare invertebrates but are not as supportive of a greater diversity of species as they could be due to the design process and a lack of knowledge of green roof technology. It was suggested that there is a need for cooperation between ecologists and Architects in order to achieve the habitat. 18 refs., 6 figs.

  6. Assessment of water quality, benthic invertebrates, and periphyton in the Threemile Creek basin, Mobile, Alabama, 1999-2003

    Science.gov (United States)

    McPherson, Ann K.; Gill, Amy C.; Moreland, Richard S.

    2005-01-01

    The U.S. Geological Survey conducted a 4-year investigation of water quality and aquatic-community structure in Threemile Creek, an urban stream that drains residential areas in Mobile, Alabama. Water-quality samples were collected between March 2000 and September 2003 at four sites on Threemile Creek, and between March 2000 and October 2001 at two tributary sites that drain heavily urbanized areas in the watershed. Stream samples were analyzed for major ions, nutrients, fecal-indicator bacteria, and selected organic wastewater compounds. Continuous measurements of dissolved-oxygen concentrations, water temperature, specific conductance, and turbidity were recorded at three sites on Threemile Creek during 1999?2003. Aquatic-community structure was evaluated by conducting one survey of the benthic invertebrate community and multiple surveys of the algal community (periphyton). Benthic invertebrate samples were collected in July 2000 at four sites on Threemile Creek; periphyton samples were collected at four sites on Threemile Creek and the two tributary sites during 2000 ?2003. The occurrence and distribution of chemical constituents in the water column provided an initial assessment of water quality in the streams; the structure of the benthic invertebrate and algal communities provided an indication of the cumulative effects of water quality on the aquatic biota. Information contained in this report can be used by planners and resource managers in the evaluation of proposed total maximum daily loads and other restoration efforts that may be implemented on Threemile Creek. The three most upstream sites on Threemile Creek had similar water chemistry, characterized by a strong calcium-bicarbonate component; the most downstream site on Threemile Creek was affected by tidal fluctuations and mixing from Mobile Bay and had a strong sodium-chloride component. The water chemistry at the tributary site on Center Street was characterized by a strong sodium-chloride component

  7. Sr and Ar isotope studies of detrital smectites from the Atlantic Ocean (D.S.D.P., Legs 43, 48 and 50)

    International Nuclear Information System (INIS)

    Clauer, N.; Lucas, J.

    1984-01-01

    Mineralogical, morphological and isotopic (Rb-Sr and K-Ar) determinations were made on some detrital smectites of Palaeocene and Cenomanian ages from D.S.D.P. drillings in the Atlantic Ocean. These minerals are not inert in their depositional environment; authigenic laths grow on detrital sheets with sharp borders. This authigenesis could occur slightly after deposition in a closed system, for some of these smectites. It has been tentatively quantified by the Rb-Sr and K-Ar isotopic methods, which seem also well suited to evaluate the chemical extent of this authigenesis. At least, no preferential loss of 40 Ar vs. 87 Sr could be detected in the minerals, even in those which are smaller than 0.2 μm. (Auth.)

  8. Contribution to the study of deep coastal detritic bottoms: the algal communities of the continental shelf off the Balearic Islands, Western Mediterranean

    Directory of Open Access Journals (Sweden)

    S. JOHER

    2015-09-01

    Full Text Available Three main algal-dominated coastal detritic communities from the continental shelf off Mallorca and Menorca (Balearic Islands, Western Mediterranean are described herein: maërl beds dominated by Spongites fruticulosus and forests of Laminaria rodriguezii located in the Menorca channel, and Peyssonnelia inamoena beds found along the Southern coast of Menorca. There seems to be a gradient of disturbance from the highly disturbed Peyssonnelia beds to the almost undisturbed L. rodriguezii forests. Whether this gradient is the result of current and past anthropogenic pressure (e.g. trawling intensity or is driven by natural environmental factors needs further assessment. Finally, the location of the target communities by means of ROV dives combined with the use of a Box-Corer dredge and beam trawl proved to be a good methodology in the study of the composition and structure of these deep water detritic communities.

  9. Nitrogen saturation in stream ecosystems.

    Science.gov (United States)

    Earl, Stevan R; Valett, H Maurice; Webster, Jackson R

    2006-12-01

    The concept of nitrogen (N) saturation has organized the assessment of N loading in terrestrial ecosystems. Here we extend the concept to lotic ecosystems by coupling Michaelis-Menten kinetics and nutrient spiraling. We propose a series of saturation response types, which may be used to characterize the proximity of streams to N saturation. We conducted a series of short-term N releases using a tracer (15NO3-N) to measure uptake. Experiments were conducted in streams spanning a gradient of background N concentration. Uptake increased in four of six streams as NO3-N was incrementally elevated, indicating that these streams were not saturated. Uptake generally corresponded to Michaelis-Menten kinetics but deviated from the model in two streams where some other growth-critical factor may have been limiting. Proximity to saturation was correlated to background N concentration but was better predicted by the ratio of dissolved inorganic N (DIN) to soluble reactive phosphorus (SRP), suggesting phosphorus limitation in several high-N streams. Uptake velocity, a reflection of uptake efficiency, declined nonlinearly with increasing N amendment in all streams. At the same time, uptake velocity was highest in the low-N streams. Our conceptual model of N transport, uptake, and uptake efficiency suggests that, while streams may be active sites of N uptake on the landscape, N saturation contributes to nonlinear changes in stream N dynamics that correspond to decreased uptake efficiency.

  10. STREAM2016: Streaming Requirements, Experience, Applications and Middleware Workshop

    Energy Technology Data Exchange (ETDEWEB)

    Fox, Geoffrey [Indiana Univ., Bloomington, IN (United States); Jha, Shantenu [Rutgers Univ., New Brunswick, NJ (United States); Ramakrishnan, Lavanya [Lawrence Berkeley National Lab. (LBNL), Berkeley, CA (United States)

    2016-10-01

    The Department of Energy (DOE) Office of Science (SC) facilities including accelerators, light sources and neutron sources and sensors that study, the environment, and the atmosphere, are producing streaming data that needs to be analyzed for next-generation scientific discoveries. There has been an explosion of new research and technologies for stream analytics arising from the academic and private sectors. However, there has been no corresponding effort in either documenting the critical research opportunities or building a community that can create and foster productive collaborations. The two-part workshop series, STREAM: Streaming Requirements, Experience, Applications and Middleware Workshop (STREAM2015 and STREAM2016), were conducted to bring the community together and identify gaps and future efforts needed by both NSF and DOE. This report describes the discussions, outcomes and conclusions from STREAM2016: Streaming Requirements, Experience, Applications and Middleware Workshop, the second of these workshops held on March 22-23, 2016 in Tysons, VA. STREAM2016 focused on the Department of Energy (DOE) applications, computational and experimental facilities, as well software systems. Thus, the role of “streaming and steering” as a critical mode of connecting the experimental and computing facilities was pervasive through the workshop. Given the overlap in interests and challenges with industry, the workshop had significant presence from several innovative companies and major contributors. The requirements that drive the proposed research directions, identified in this report, show an important opportunity for building competitive research and development program around streaming data. These findings and recommendations are consistent with vision outlined in NRC Frontiers of Data and National Strategic Computing Initiative (NCSI) [1, 2]. The discussions from the workshop are captured as topic areas covered in this report's sections. The report

  11. A new parameterization for surface ocean light attenuation in Earth System Models: assessing the impact of light absorption by colored detrital material

    OpenAIRE

    G. E. Kim; M.-A. Pradal; A. Gnanadesikan

    2015-01-01

    Light limitation can affect the distribution of biota and nutrients in the ocean. Light absorption by colored detrital material (CDM) was included in a fully coupled Earth System Model using a new parameterization for shortwave attenuation. Two model runs were conducted, with and without light attenuation by CDM. In a global average sense, greater light limitation associated with CDM increased surface chlorophyll, biomass and nutrients together. These changes can be attribut...

  12. Elucidating tectonic events and processes from variably tectonized conglomerate clast detrital geochronology: examples from the Hongliuhe Formation in the southern Central Asian Orogenic Belt, NW China

    Science.gov (United States)

    Cleven, Nathan; Lin, Shoufa; Davis, Donald; Xiao, Wenjiao; Guilmette, Carl

    2017-04-01

    This work expands upon detrital zircon geochronology with a sampling and analysis strategy dating granitoid conglomerate clasts that exhibit differing degrees of internal ductile deformation. As deformation textures within clastic material reflect the variation and history of tectonization in the source region of a deposit, we outline a dating methodology that can provide details of the provenance's tectonomagmatic history from deformation-relative age distributions. The method involves bulk samples of solely granitoid clasts, as they are representative of the magmatic framework within the provenance. The clasts are classified and sorted into three subsets: undeformed, slightly deformed, and deformed. LA-ICPMS U-Pb geochronology is performed on zircon separates of each subset. Our case study, involving the Permian Hongliuhe Formation in the southern Central Asian Orogenic Belt, analyzes each of the three clast subsets, as well as sandstone detrital samples, at three stratigraphic levels to yield a profile of the unroofed provenance. The age spectra of the clast samples exhibit different, wider distributions than sandstone samples, considered an effect of proximity to the respective provenance. Comparisons of clast data to sandstone data, as well as comparisons between stratigraphic levels, yield indications of key tectonic processes, in addition to the typical characteristics provided by detrital geochronology. The clast data indicates a minimal lag time, implying rapid exhumation rates, whereas sandstone data alone would indicate a 90 m.y. lag time. Early Paleozoic arc building episodes appear as Ordovician peaks in sandstone data, and Silurian-Devonian peaks in clast data, indicating a younging of magmatism towards the proximal provenance. A magmatic hiatus starts in the Devonian, correlating with the latest age of deformed clasts, interpreted as timing of collisional tectonics. Provenance interpretation using the correlations seen between the clast and sandstone

  13. Galaxies with jet streams

    International Nuclear Information System (INIS)

    Breuer, R.

    1981-01-01

    Describes recent research work on supersonic gas flow. Notable examples have been observed in cosmic radio sources, where jet streams of galactic dimensions sometimes occur, apparently as the result of interaction between neighbouring galaxies. The current theory of jet behaviour has been convincingly demonstrated using computer simulation. The surprisingly long-term stability is related to the supersonic velocity, and is analagous to the way in which an Appollo spacecraft re-entering the atmosphere supersonically is protected by the gas from the burning shield. (G.F.F.)

  14. Oscillating acoustic streaming jet

    International Nuclear Information System (INIS)

    Moudjed, Brahim; Botton, Valery; Henry, Daniel; Millet, Severine; Ben Hadid, Hamda; Garandet, Jean-Paul

    2014-01-01

    The present paper provides the first experimental investigation of an oscillating acoustic streaming jet. The observations are performed in the far field of a 2 MHz circular plane ultrasound transducer introduced in a rectangular cavity filled with water. Measurements are made by Particle Image Velocimetry (PIV) in horizontal and vertical planes near the end of the cavity. Oscillations of the jet appear in this zone, for a sufficiently high Reynolds number, as an intermittent phenomenon on an otherwise straight jet fluctuating in intensity. The observed perturbation pattern is similar to that of former theoretical studies. This intermittently oscillatory behavior is the first step to the transition to turbulence. (authors)

  15. The metaphors we stream by: Making sense of music streaming

    OpenAIRE

    Hagen, Anja Nylund

    2016-01-01

    In Norway music-streaming services have become mainstream in everyday music listening. This paper examines how 12 heavy streaming users make sense of their experiences with Spotify and WiMP Music (now Tidal). The analysis relies on a mixed-method qualitative study, combining music-diary self-reports, online observation of streaming accounts, Facebook and last.fm scrobble-logs, and in-depth interviews. By drawing on existing metaphors of Internet experiences we demonstrate that music-streaming...

  16. Invertebrate communities of Arctic tundra ponds as related to proximity to drill site reserve pits

    International Nuclear Information System (INIS)

    Byron, E.; Williams, N.; Hoffman, R.; Elder, B.

    1994-01-01

    Aquatic invertebrate communities were assessed for diversity and abundance in North Slope tundra ponds of Prudhoe Bay, Alaska during the summer of 1992 as part of an evaluation of potential effects of exposure to petroleum drill site reserve pits (previously used for storing drill site wastes). The invertebrate communities of these shallow, tundra ponds provide abundant food for migratory, aquatic birds that use this area during the summer breeding season. The study was designed to compare abundance and diversity estimates of invertebrates in ponds surrounding the drill sites that differed in distance (and presumed exposure) to drill site reserve pits. The pits, themselves, were not sampled as part of this study. Invertebrate abundance and diversity estimates, assessed as standard biological criteria, were evaluated relative to water chemistry of the ponds, distance to the gravel pads or reserve pits, and pond morphometry. The results indicated the importance of pond morphometry in determining the structure of the invertebrate community. Shallow, exposed ponds tended to be dominated by different invertebrate communities than deeper, narrow ponds at the margins of frost polygons. In contrast, pond chemistry and relative exposure to drill sites were not predictive of invertebrate abundance or diversity

  17. Acute toxicity and inactivation tests of CO2 on invertebrates in drinking water treatment systems.

    Science.gov (United States)

    Yin, Wen-Chao; Zhang, Jin-Song; Liu, Li-Jun; Zhao, Jian-Shu; Li, Tuo

    2011-01-01

    In addition to the esthetic problem caused by invertebrates, researchers are recently starting to be more aware of their potential importance in terms of public health. However, the inactivation methods of invertebrates which could proliferate in drinking water treatment systems are not well developed. The objective of this study is to assess the acute toxicity and inactivation effects of CO2 on familiar invertebrates in water treatment processes. The results of this study revealed that CO2 has a definite toxicity to familiar invertebrates. The values of 24-h LC50 (median lethal concentration) were calculated for each test with six groups of invertebrates. The toxicity of CO2 was higher with increasing concentrations in solution but was lower with the increase in size of the invertebrates. Above the concentration of 1,000 mg/L for the CO2 solution, the 100% inactivation time of all the invertebrates was less than 5 s, and in 15 min, the inactivation ratio showed a gradient descent with a decline in concentration. As seen for Mesocyclops thermocyclopoides, by dosing with a sodium bicarbonate solution first and adding a dilute hydrochloric acid solution 5 min later, it is possible to obtain a satisfactory inactivation effect in the GAC (granular activated carbon) filters.

  18. Comparative biology of pain: What invertebrates can tell us about how nociception works.

    Science.gov (United States)

    Burrell, Brian D

    2017-04-01

    The inability to adequately treat chronic pain is a worldwide health care crisis. Pain has both an emotional and a sensory component, and this latter component, nociception, refers specifically to the detection of damaging or potentially damaging stimuli. Nociception represents a critical interaction between an animal and its environment and exhibits considerable evolutionary conservation across species. Using comparative approaches to understand the basic biology of nociception could promote the development of novel therapeutic strategies to treat pain, and studies of nociception in invertebrates can provide especially useful insights toward this goal. Both vertebrates and invertebrates exhibit segregated sensory pathways for nociceptive and nonnociceptive information, injury-induced sensitization to nociceptive and nonnociceptive stimuli, and even similar antinociceptive modulatory processes. In a number of invertebrate species, the central nervous system is understood in considerable detail, and it is often possible to record from and/or manipulate single identifiable neurons through either molecular genetic or physiological approaches. Invertebrates also provide an opportunity to study nociception in an ethologically relevant context that can provide novel insights into the nature of how injury-inducing stimuli produce persistent changes in behavior. Despite these advantages, invertebrates have been underutilized in nociception research. In this review, findings from invertebrate nociception studies are summarized, and proposals for how research using invertebrates can address questions about the fundamental mechanisms of nociception are presented. Copyright © 2017 the American Physiological Society.

  19. Phylogenetically diverse macrophyte community promotes species diversity of mobile epi-benthic invertebrates

    Science.gov (United States)

    Nakamoto, Kenta; Hayakawa, Jun; Kawamura, Tomohiko; Kodama, Masafumi; Yamada, Hideaki; Kitagawa, Takashi; Watanabe, Yoshiro

    2018-07-01

    Various aspects of plant diversity such as species diversity and phylogenetic diversity enhance the species diversity of associated animals in terrestrial systems. In marine systems, however, the effects of macrophyte diversity on the species diversity of associated animals have received little attention. Here, we sampled in a subtropical seagrass-seaweed mixed bed to elucidate the effect of the macrophyte phylogenetic diversity based on the taxonomic relatedness as well as the macrophyte species diversity on species diversity of mobile epi-benthic invertebrates. Using regression analyses for each macrophyte parameter as well as multiple regression analyses, we found that the macrophyte phylogenetic diversity (taxonomic diversity index: Delta) positively influenced the invertebrate species richness and diversity index (H‧). Although the macrophyte species richness and H‧ also positively influenced the invertebrate species richness, the best fit model for invertebrate species richness did not include them, suggesting that the macrophyte species diversity indirectly influenced invertebrate species diversity. Possible explanations of the effects of macrophyte Delta on the invertebrate species diversity were the niche complementarity effect and the selection effect. This is the first study which demonstrates that macrophyte phylogenetic diversity has a strong effect on the species diversity of mobile epi-benthic invertebrates.

  20. Functional traits of soil invertebrates as indicators for exposure to soil disturbance

    International Nuclear Information System (INIS)

    Hedde, Mickaël; Oort, Folkert van; Lamy, Isabelle

    2012-01-01

    We tested a trait-based approach to link a soil disturbance to changes in invertebrate communities. Soils and macro-invertebrates were sampled in sandy soils contaminated by long-term wastewater irrigation, adding notably organic matter and trace metals (TM). We hypothesized that functional traits of invertebrates depict ways of exposure and that exposure routes relate to specific TM pools. Geophages and soft-body invertebrates were chosen to inform on exposure by ingestion or contact, respectively. Trait-based indices depicted more accurately effects of pollution than community density and diversity did. Exposure by ingestion had more deleterious effects than by contact. Both types of exposed invertebrates were influenced by TM, but geophages mainly responded to changes in soil organic matter contents. The trait-based approach requires to be applied in various conditions to uncorrelate specific TM impacts from those of other environmental factors. - Highlights: ► We linked pollution, exposure routes and impacts on soil invertebrates. ► Proportions of exposed animals accurately depicted pollution effects. ► Exposure by ingestion had more deleterious effects than exposure by contact. ► Geophages decline reflected changes in soil organic matter. ► Soft-body proportions were mainly influenced by TM pools. - A trait-based approach hierarchized impacts of soil pollution on soil invertebrate communities following ways of exposure

  1. Development of biotic ligand models for chronic manganese toxicity to fish, invertebrates, and algae.

    Science.gov (United States)

    Peters, Adam; Lofts, Stephen; Merrington, Graham; Brown, Bruce; Stubblefield, William; Harlow, Keven

    2011-11-01

    Ecotoxicity tests were performed with fish, invertebrates, and algae to investigate the effect of water quality parameters on Mn toxicity. Models were developed to describe the effects of Mn as a function of water quality. Calcium (Ca) has a protective effect on Mn toxicity for both fish and invertebrates, and magnesium (Mg) also provides a protective effect for invertebrates. Protons have a protective effect on Mn toxicity to algae. The models derived are consistent with models of the toxicity of other metals to aquatic organisms in that divalent cations can act as competitors to Mn toxicity in fish and invertebrates, and protons act as competitors to Mn toxicity in algae. The selected models are able to predict Mn toxicity to the test organisms to within a factor of 2 in most cases. Under low-pH conditions invertebrates are the most sensitive taxa, and under high-pH conditions algae are most sensitive. The point at which algae become more sensitive than invertebrates depends on the Ca concentration and occurs at higher pH when Ca concentrations are low, because of the sensitivity of invertebrates under these conditions. Dissolved organic carbon concentrations have very little effect on the toxicity of Mn to aquatic organisms. Copyright © 2011 SETAC.

  2. Invertebrate populations in miscanthus (Miscanthusxgiganteus) and reed canary-grass (Phalaris arundinacea) fields

    Energy Technology Data Exchange (ETDEWEB)

    Semere, T.; Slater, F.M. [Llysdinam Field Centre, School of Biosciences, Cardiff University, Newbridge-on-Wye, Llandrindod Wells, Powys, LD1 6NB (United Kingdom)

    2007-01-15

    Monitoring of invertebrates at four field sites in Herefordshire, England, growing miscanthus and reed canary-grass was carried out in 2002, 2003 and 2004 to investigate the ecological impact of these crops on ground beetles, butterflies and arboreal invertebrates. Ground beetles were sampled by pitfall trapping; and arboreal invertebrates by sweep netting and stem beating. The Centre for Ecology and Hydrology's Butterflies Monitoring Scheme methodology was used to record butterflies. The effects of the biomass crops on invertebrates were indirect, through the use of weeds as food resources and habitat. The greater diversity of weed flora within miscanthus fields than within reed canary-grass fields had a greater positive effect on invertebrates. Ground beetles, butterflies and arboreal invertebrates were more abundant and diverse in the most floristically diverse miscanthus fields. The difference in crop architecture and development between miscanthus and reed canary-grass was reflected in their differences in crop height and ground cover early on in the season. However, most of the difference in arthropod abundance between the two crops was attributed to the difference in the agronomic practice of growing the crops such as plant density, and the effect of this on weed growth. Since perennial rhizomatous grasses require a single initial planting and related tillage, and also no major chemical inputs; and because the crops are harvested in the spring and the land is not disturbed by cultivation every year, the fields were used as over-wintering sites for invertebrates suggesting immediate benefits to biodiversity. (author)

  3. Using a C4 Invasive Grass to Isolate the Role of Detrital Carbon versus Rhizodeposit Carbon in Supplying Soil Carbon Pools

    Science.gov (United States)

    Sokol, N.; Bradford, M.

    2016-12-01

    Plant inputs are the primary sources of carbon (C) to soil organic carbon (SOC) pools. Historically, detrital plant sources were thought to dominate C supply to SOC pools. An emerging body of research highlights the previously underestimated role of root exudates and other rhizodeposits. However, few experimental field studies have directly tracked the relative contributions of rhizodeposits versus detritial C inputs into different SOC pools, due to how methodologically challenging they are to measure in a field setting. Here, I present the first 3 years of data from an experimental field study of the prolific, C4 invasive grass species Microstegium vimineum. I use its unique isotopic signature in plots manipulated to contain detrital-only and rhizodeposit-only inputs, to track their relative contributions into microbial biomass C, particulate organic C (POC; >53 um) and mineral-associated organic C (MIN C; emerging theory on the primacy of the belowground, root-associated pathway in supplying C to soil C pools, this increase is generally assumed to be through the MIN C pool due to 1) the lower molecular weight of rhizodeposit compounds, and 2) the close physical association between rhizodeposits and soil mineral surfaces. Our results point to an underappreciated, central role of the POM C pool as a passageway for both detrital and rhizodeposit C inputs to the soil.

  4. Petrogenesis, detrital zircon SHRIMP U-Pb geochronology, and tectonic implications of the Upper Paleoproterozoic Seosan iron formation, western Gyeonggi Massif, Korea

    Science.gov (United States)

    Kim, Chang Seong; Jang, Yirang; Samuel, Vinod O.; Kwon, Sanghoon; Park, Jung-Woo; Yi, Keewook; Choi, Seon-Gyu

    2018-05-01

    This study involves investigations on the Upper Paleoproterozoic iron formation (viz., Seosan iron formation) from the Seosan Group, Gyeonggi Massif of the southwestern Korean Peninsula. It occurs as thin banded layers within meta-arkosic sandstone, formed by alternating processes of chemical (hydrothermal) and detrital depositions under a shallow marine environment. It mainly consists of alternating layers of iron oxides, mostly hematite, and quartz. Minor amounts of magnetite surrounded by muscovite, clinopyroxene and amphibole indicate hydrothermal alteration since its formation. Meta-arkosic sandstone is composed of recrystallized or porphyroclastic quartz and microcline, with small amounts of hematite and pyrite clusters. The Seosan iron formation has high contents of total Fe2O3 and SiO2 with positive Eu anomalies similar to those of other Precambrian banded iron formations, and its formation is clearly related to hydrothermal alteration since its deposition. Detrital zircon SHRIMP U-Pb geochronology data from a meta-arkosic sandstone (SN-1) and an iron formation (SN-2) show mainly two age groups of ca. 2.5 Ga and ca. 1.9-1.75 Ga. This together with intrusion age of the granite gneiss (ca. 1.70-1.65 Ga) clearly indicate that the iron formations were deposited during the Upper Paleoproterozoic. The dominant Paleoproterozoic detrital zircon bimodal age peaks preserved in the Seosan iron formation compare well with those from the South China Craton sedimentary basins, reflecting global tectonic events related to the Columbia supercontinent in East Asia.

  5. U-Pb detrital zircon geochronology from the basement of the Central Qilian Terrane: implications for tectonic evolution of northeastern Tibetan Plateau

    Science.gov (United States)

    Liu, Changfeng; Wu, Chen; Zhou, Zhiguang; Yan, Zhu; Jiang, Tian; Song, Zhijie; Liu, Wencan; Yang, Xin; Zhang, Hongyuan

    2018-03-01

    The Tuolai Group dominates the Central Qilian Terrane, and there are different opinions on the age and tectonic attribute of the Tuolai Group. Based on large-scale geologic mapping and zircon dating, the Tuolai Group is divided into four parts: metamorphic supracrustal rocks, Neoproterozoic acid intrusive rocks, early-middle Ordovician acid intrusive rocks and middle Ordovician basic intrusive rocks. The metamorphic supracrustal rocks are the redefined Tuolai complex-group and include gneiss and schist assemblage by faulting contact. Zircon U-Pb LA-MC-ICP-MS dating was conducted on these samples of gneiss and migmatite from the gneiss assemblage, quartzite, two-mica schist and slate from the schist assemblage. The five detrital samples possess similar age spectra; have detrital zircon U-Pb main peak ages of 1.7 Ga with youngest U-Pb ages of 1150 Ma. They are intruded by Neoproterozoic acid intrusive rocks. Therefore, the Tuolai Group belonging to late Mesoproterozoic and early Neoproterozoic. With this caveat in mind, we believe that U-Pb detrital zircon dating, together with the geologic constraints obtained from this study and early work in the neighboring regions. We suggest that the formation age of the entire crystalline basement rocks of metasedimentary sequence from the Central Qilian Terrane should be constrained between the Late Mesoproterozoic and the Late Neoproterozoic, but not the previous Paleoproterozoic. The basement of the Central Qilian Terrane contains the typical Grenville ages, which indicates the Centre Qilian Terrane have been experienced the Grenville orogeny event.

  6. Identification of multiple detrital sources for Otway Supergroup sedimentary rocks: implications for basin models and chronostratigraphic correlations

    International Nuclear Information System (INIS)

    Mitchell, M.M.

    1997-01-01

    Correlation of apatite chlorine content (wt%) with apatite fission track age (Ma) from Lower Cretaceous Otway Supergroup sediments at present-day low temperatures, allows identification of two characteristic detrital source regions. Apatites from eroded Palaeozoic basement terrains yield low Cl content (generally 0.5 wt%) and syndepositional fission track ages. Where post-depositional thermal annealing ( > 70 degree C) has significantly reduced the fission track age, provenance information is preserved in the apatite Cl composition alone. In the Otway Supergroup, evidence for contemporaneous volcanism was found in both the Eumeralla Formation (Albian-Aptian), and Crayfish Group (Aptian-Berriasian) in samples located towards the central rift, where less sandy facies dominate. Results suggest that Crayfish Group sediments deposited along the northern margin of the basin were predominantly derived from eroding basement material, while the section located towards the central rift contains a greater proportion of volcanogenic detritus. Evidence from this study suggests that volcanogenic detritus was a distal sediment source throughout the entire early rift phase, prior to the main influx of arc-related volcanogenic material during deposition of the Eumeralla Formation. As diagenesis of volcanogenic sediments significantly reduces porosity and permeability of the sandstones, reservoir quality and petroleum potential may be significantly reduced in the Crayfish Group in deeper parts of the basin where a greater proportion of volcanogenic detritus is suggested. The results presented here provide important information regarding Lower Cretaceous Otway Basin stratigraphy and clearly indicate that this methodology may have wider application. (authors)

  7. Spectral slopes of the absorption coefficient of colored dissolved and detrital material inverted from UV-visible remote sensing reflectance.

    Science.gov (United States)

    Wei, Jianwei; Lee, Zhongping; Ondrusek, Michael; Mannino, Antonio; Tzortziou, Maria; Armstrong, Roy

    2016-03-01

    The spectral slope of the absorption coefficient of colored dissolved and detrital material (CDM), S cdm (units: nm -1 ), is an important optical parameter for characterizing the absorption spectral shape of CDM. Although highly variable in natural waters, in most remote sensing algorithms, this slope is either kept as a constant or empirically modeled with multiband ocean color in the visible domain. In this study, we explore the potential of semianalytically retrieving S cdm with added ocean color information in the ultraviolet (UV) range between 360 and 400 nm. Unique features of hyperspectral remote sensing reflectance in the UV-visible wavelengths (360-500 nm) have been observed in various waters across a range of coastal and open ocean environments. Our data and analyses indicate that ocean color in the UV domain is particularly sensitive to the variation of the CDM spectral slope. Here, we used a synthesized data set to show that adding UV wavelengths to the ocean color measurements will improve the retrieval of S cdm from remote sensing reflectance considerably, while the spectral band settings of past and current satellite ocean color sensors cannot fully account for the spectral variation of remote sensing reflectance. Results of this effort support the concept to include UV wavelengths in the next generation of satellite ocean color sensors.

  8. U-Pb and Hf isotope analysis of detrital zircons from Mesozoic strata of the Gravina belt, southeast Alaska

    Science.gov (United States)

    Yokelson, Intan; Gehrels, George E.; Pecha, Mark; Giesler, Dominique; White, Chelsi; McClelland, William C.

    2015-10-01

    The Gravina belt consists of Upper Jurassic through Lower Cretaceous marine clastic strata and mafic-intermediate volcanic rocks that occur along the western flank of the Coast Mountains in southeast Alaska and coastal British Columbia. This report presents U-Pb ages and Hf isotope determinations of detrital zircons that have been recovered from samples collected from various stratigraphic levels and from along the length of the belt. The results support previous interpretations that strata in the western portion of the Gravina belt accumulated along the inboard margin of the Alexander-Wrangellia terrane and in a back-arc position with respect to the western Coast Mountains batholith. Our results are also consistent with previous suggestions that eastern strata accumulated along the western margin of the inboard Stikine, Yukon-Tanana, and Taku terranes and in a fore-arc position with respect to the eastern Coast Mountains batholith. The history of juxtaposition of western and eastern assemblages is obscured by subsequent plutonism, deformation, and metamorphism within the Coast Mountains orogen, but may have occurred along an Early Cretaceous sinistral transform system. Our results are inconsistent with models in which an east-facing subduction zone existed along the inboard margin of the Alexander-Wrangellia terrane during Late Jurassic-Early Cretaceous time.

  9. The application of PIT tags to measure transport of detrital coral fragments on a fringing reef: Majuro Atoll, Marshall Islands

    Science.gov (United States)

    Ford, Murray R.

    2014-06-01

    Passive integrated transponder (PIT) tags are a radio-frequency identification device widely used as a machine-readable identification tool in fisheries research. PIT tags have also been employed, to a lesser extent, to track the movement of gravel-sized clasts within fluvial and coastal systems. In this study, PIT tags were inserted into detrital coral fragments and used to establish source-sink transport pathways on a fringing reef on Majuro Atoll in the Marshall Islands. Results suggest the transport of gravel-sized material on the inter-tidal reef flat is exclusively across-reef towards the lagoon. Considerable variation in the distance travelled by fragments was observed. Fragments were largely intact and visually recognisable after almost 5 months on the reef flat. However, the branches of some recovered fragments had broken off and corallite abrasion was observed in recovered fragments. This study indicates that PIT tags are an inexpensive and powerful new addition to the suite of sediment transport and taphonomic tools for researchers working within coral reef systems.

  10. Detrital U-Pb zircon analysis of an Eocene McMurdo Erratic sandstone, McMurdo Sound, Antarctica

    International Nuclear Information System (INIS)

    Paulsen, T.; Encarnacion, J.; Valencia, V.A.; Roti Roti, J.M.; Rasoazanamparany, C.

    2011-01-01

    Some of the most important Cenozoic sedimentary rocks in Antarctica are glacial erratics of fossiliferous Palaeogene to Neogene siliclastic rocks known as the McMurdo Erratics. Detrital zircon U-Pb isotopic data reported herein provide new information on the provenance of these siliciclastic rocks. The U-Pb age data from a sandstone glacial erratic that is likely of Eocene age show a dominant age cluster that ranges from 488 to 635 Ma, accompanied by subsidiary Neoproterozoic-Archaean peaks. The dominant Neoproterozoic-Ordovician age cluster, in conjunction with the arkosic lithologies of some erratics and the local presence of granitic and metasedimentary clasts, indicates that the Neoproterozoic-Ordovician basement complex of the Transantarctic Mountains likely served as a major source for the Eocene siliciclastic sediments. This is consistent with derivation of the McMurdo Erratics from locations proximal to the Transantarctic Mountains such as the Discovery Deep and/or major mountain outlet glacier areas. (author). 19 refs., 3 figs., 1 tab.

  11. Tracking Gendered Streams

    Directory of Open Access Journals (Sweden)

    Maria Eriksson

    2017-10-01

    Full Text Available One of the most prominent features of digital music services is the provision of personalized music recommendations that come about through the profiling of users and audiences. Based on a range of "bot experiments," this article investigates if, and how, gendered patterns in music recommendations are provided by the streaming service Spotify. While our experiments did not give any strong indications that Spotify assigns different taste profiles to male and female users, the study showed that male artists were highly overrepresented in Spotify's music recommendations; an issue which we argue prompts users to cite hegemonic masculine norms within the music industries. Although the results should be approached as historically and contextually contingent, we argue that they point to how gender and gendered tastes may be constituted through the interplay between users and algorithmic knowledge-making processes, and how digital content delivery may maintain and challenge gender relations and gendered power differentials within the music industries. Seen through the lens of critical research on software, music and gender performativity, the experiments thus provide insights into how gender is shaped and attributed meaning as it materializes in contemporary music streams.

  12. The LHCb Turbo stream

    CERN Document Server

    AUTHOR|(CDS)2070171

    2016-01-01

    The LHCb experiment will record an unprecedented dataset of beauty and charm hadron decays during Run II of the LHC, set to take place between 2015 and 2018. A key computing challenge is to store and process this data, which limits the maximum output rate of the LHCb trigger. So far, LHCb has written out a few kHz of events containing the full raw sub-detector data, which are passed through a full offline event reconstruction before being considered for physics analysis. Charm physics in particular is limited by trigger output rate constraints. A new streaming strategy includes the possibility to perform the physics analysis with candidates reconstructed in the trigger, thus bypassing the offline reconstruction. In the Turbo stream the trigger will write out a compact summary of physics objects containing all information necessary for analyses. This will allow an increased output rate and thus higher average efficiencies and smaller selection biases. This idea will be commissioned and developed during 2015 wi...

  13. Food web of a tropical high mountain stream: Effects of nutrient addition

    International Nuclear Information System (INIS)

    Castro Rebolledo, Maria Isabel; Munoz Gracia, Isabel; Donato Rondon, John Charles

    2014-01-01

    Using a nutrient enrichment experiment in an Andean mountain stream, we used stable isotope ratios (δ 15n and δ13c) to analyze different trophic compartments: 1) basal level: CPOM and biofilm; 2) primary consumers - macro invertebrates: collector-gatherers(heterelmissp, thraulodessp andtrichorythodessp), and collector-filterers (simuliumsp); 3) predators - fish (oncorhynchusmykiss and trichomycterusbogotensis). the average fractionation of nitrogen among the primary consumers with respect to CPOM was 4.7 and 1.7 with respect to biofilm. predators incremented their δ15n signal by 5.9% with respect to primary consumers. A depletion of δ15n was observed in impact with respect to control reach after fertilization in different compartments (biofilm, heterelmissp., simuliumsp. andtricorythodessp.), while depletion was not significant for top predators. In most cases, the δ13c signal of biofilm overlapped with that of primary consumers, but a clear enrichment was observed with respect to CPOM. The macro invertebrates referred to were selected to analyze their gut content and the results showed us that fine detritus is the most abundant food in invertebrates, and onlyheterelmis sp. showed significant differences in fine detritus and vegetal matter between control and impact reaches after the nutrient addition.

  14. Beyond cool: adapting upland streams for climate change using riparian woodlands.

    Science.gov (United States)

    Thomas, Stephen M; Griffiths, Siân W; Ormerod, Steve J

    2016-01-01

    Managed adaptation could reduce the risks of climate change to the world's ecosystems, but there have been surprisingly few practical evaluations of the options available. For example, riparian woodland is advocated widely as shade to reduce warming in temperate streams, but few studies have considered collateral effects on species composition or ecosystem functions. Here, we use cross-sectional analyses at two scales (region and within streams) to investigate whether four types of riparian management, including those proposed to reduce potential climate change impacts, might also affect the composition, functional character, dynamics and energetic resourcing of macroinvertebrates in upland Welsh streams (UK). Riparian land use across the region had only small effects on invertebrate taxonomic composition, while stable isotope data showed how energetic resources assimilated by macroinvertebrates in all functional guilds were split roughly 50:50 between terrestrial and aquatic origins irrespective of riparian management. Nevertheless, streams draining the most extensive deciduous woodland had the greatest stocks of coarse particulate matter (CPOM) and greater numbers of 'shredding' detritivores. Stream-scale investigations showed that macroinvertebrate biomass in deciduous woodland streams was around twice that in moorland streams, and lowest of all in streams draining non-native conifers. The unexpected absence of contrasting terrestrial signals in the isotopic data implies that factors other than local land use affect the relative incorporation of allochthonous subsidies into riverine food webs. Nevertheless, our results reveal how planting deciduous riparian trees along temperate headwaters as an adaptation to climate change can modify macroinvertebrate function, increase biomass and potentially enhance resilience by increasing basal resources where cover is extensive (>60 m riparian width). We advocate greater urgency in efforts to understand the ecosystem

  15. Characterisation (δ13C and δ15N isotopes) of the food webs in a New Zealand stream in the Waitakere Ranges, with emphasis on the trophic level of the endemic frog Leiopelma hochstetteri

    International Nuclear Information System (INIS)

    Najera-Hillman, E.; Alfaro, A.C.; Breen, B.B.; O'Shea, S.

    2009-01-01

    Leiopelma hochstetteri, the most widespread of New Zealand's native frogs, is recognised as threatened, and is fully protected by legislation. As a first step to characterise the diet and trophic level of L. hochstetteri within streams in the Waitakere Ranges, Auckland, stable carbon and nitrogen isotope analyses were undertaken on a variety of sympatric terrestrial and aquatic plant and animal species, including adult frogs. These results show that: (1) aquatic and terrestrial food webs are linked by terrestrial inputs into the stream; (2) invertebrate and vertebrate predators separate well into distinct trophic groups, and (3) L. hochstetteri occupies an intermediate trophic position among predators, with a diet, at least as an adult, comprising terrestrial invertebrates. Shortfin eels and banded kokopu are identified as potential predators of L. hochstetteri, but data for rats are inconclusive. These results have important implications for the conservation of New Zealand native frog species and riparian stream habitat. (author). 75 refs., 3 figs., 1 tab

  16. Molecular Architecture and Biomedical Leads of Terpenes from Red Sea Marine Invertebrates

    Science.gov (United States)

    Hegazy, Mohamed Elamir F.; Mohamed, Tarik A.; Alhammady, Montaser A.; Shaheen, Alaa M.; Reda, Eman H.; Elshamy, Abdelsamed I.; Aziz, Mina; Paré, Paul W.

    2015-01-01

    Marine invertebrates including sponges, soft coral, tunicates, mollusks and bryozoan have proved to be a prolific source of bioactive natural products. Among marine-derived metabolites, terpenoids have provided a vast array of molecular architectures. These isoprenoid-derived metabolites also exhibit highly specialized biological activities ranging from nerve regeneration to blood-sugar regulation. As a result, intense research activity has been devoted to characterizing invertebrate terpenes from both a chemical and biological standpoint. This review focuses on the chemistry and biology of terpene metabolites isolated from the Red Sea ecosystem, a unique marine biome with one of the highest levels of biodiversity and specifically rich in invertebrate species. PMID:26006713

  17. Recovery of invertebrate and vertebrate populations in a coal ash stressed drainage system

    Energy Technology Data Exchange (ETDEWEB)

    Cherry, D.S.; Larrick, S.R.; Guthrie, R.K.; Davis, E.M.; Sherberger, F.F.

    1979-09-01

    The influence of coal ash effluent on the densities of macrobenthic invertebrate and mosquitofish populations in a swamp drainage system was studied. Samples were collected during a period of 50 mo. Three perturbations in the swamp systemash siltation, low pH, and toxic elementscaused changes in population densities. Siltation from inefficient effluent management caused the greatest drop in invertebrate populations, and pH declines from flyash addition caused the greatest mosquitofish population reductions. Dipterans and odonates were most tolerant to coal ash stress. Invertebrate population recovery was observed on completion of an efficient ash retaining basin. (13 graphs, 28 references, 3 tables)

  18. Arsenic in terrestrial invertebrates from riparian areas of the Piracicaba River Basin, Sao Paulo State, Brazil

    International Nuclear Information System (INIS)

    Franca, E.J.; Magalhaes, M.R.L.; Santos, M.L.O.; Nadai Fernandes, E.A. de; Fonseca, F.Y.

    2017-01-01

    There is no information on arsenic distribution in terrestrial invertebrates from riparian forests of urban and rural areas in Brazil. The objective of this study was to evaluate the As levels in invertebrates from riverine forests of the Piracicaba River Basin, Sao Paulo, Brazil, using the instrumental neutron activation analysis, k 0 -comparator method. After correction of mass fractions, values higher than 0.10 mg kg -1 were quantified in invertebrates from both urban and agricultural areas. An unexpected As mass fraction of 13 mg kg -1 obtained in the Coleopteran pest Macrodactylus pumilio indicated resistance to As-containing-pesticides. (author)

  19. Molecular Architecture and Biomedical Leads of Terpenes from Red Sea Marine Invertebrates

    Directory of Open Access Journals (Sweden)

    Mohamed Elamir F. Hegazy

    2015-05-01

    Full Text Available Marine invertebrates including sponges, soft coral, tunicates, mollusks and bryozoan have proved to be a prolific source of bioactive natural products. Among marine-derived metabolites, terpenoids have provided a vast array of molecular architectures. These isoprenoid-derived metabolites also exhibit highly specialized biological activities ranging from nerve regeneration to blood-sugar regulation. As a result, intense research activity has been devoted to characterizing invertebrate terpenes from both a chemical and biological standpoint. This review focuses on the chemistry and biology of terpene metabolites isolated from the Red Sea ecosystem, a unique marine biome with one of the highest levels of biodiversity and specifically rich in invertebrate species.

  20. Standing crops and ecology of aquatic invertebrates in agricultural drainwater ponds in California

    Science.gov (United States)

    Euliss, N.H.; Jarvis, R.L.; Gilmer, D.S.

    1991-01-01

    We examined standing crops and ecology of aquatic invertebrates in agricultural drainwater evaporation ponds in California from October 1982 to March 1983 and September 1983 to March 1984. Evaporation ponds supported low diversities but high standing crops of aquatic invertebrates. A water boatman (Trichocorixa reticulata) and a midge (Tanypus grodhausi) were the most abundant invertebrates, constituting 44.9% and 51.4% of total macroinvertebrate biomass. Regression models indicated that of 6 environmental variables measured, only electrical conductivity (EC) and Julian date affected biomass and density of water boatmen. EC was the only significant correlate of midge biomass in evaporation ponds.

  1. Stream Lifetimes Against Planetary Encounters

    Science.gov (United States)

    Valsecchi, G. B.; Lega, E.; Froeschle, Cl.

    2011-01-01

    We study, both analytically and numerically, the perturbation induced by an encounter with a planet on a meteoroid stream. Our analytical tool is the extension of pik s theory of close encounters, that we apply to streams described by geocentric variables. The resulting formulae are used to compute the rate at which a stream is dispersed by planetary encounters into the sporadic background. We have verified the accuracy of the analytical model using a numerical test.

  2. Morphology of a Wetland Stream

    Science.gov (United States)

    Jurmu; Andrle

    1997-11-01

    / Little attention has been paid to wetland stream morphology in the geomorphological and environmental literature, and in the recently expanding wetland reconstruction field, stream design has been based primarily on stream morphologies typical of nonwetland alluvial environments. Field investigation of a wetland reach of Roaring Brook, Stafford, Connecticut, USA, revealed several significant differences between the morphology of this stream and the typical morphology of nonwetland alluvial streams. Six morphological features of the study reach were examined: bankfull flow, meanders, pools and riffles, thalweg location, straight reaches, and cross-sectional shape. It was found that bankfull flow definitions originating from streams in nonwetland environments did not apply. Unusual features observed in the wetland reach include tight bends and a large axial wavelength to width ratio. A lengthy straight reach exists that exceeds what is typically found in nonwetland alluvial streams. The lack of convex bank point bars in the bends, a greater channel width at riffle locations, an unusual thalweg location, and small form ratios (a deep and narrow channel) were also differences identified. Further study is needed on wetland streams of various regions to determine if differences in morphology between alluvial and wetland environments can be applied in order to improve future designs of wetland channels.KEY WORDS: Stream morphology; Wetland restoration; Wetland creation; Bankfull; Pools and riffles; Meanders; Thalweg

  3. Analyzing indicators of stream health for Minnesota streams

    Science.gov (United States)

    Singh, U.; Kocian, M.; Wilson, B.; Bolton, A.; Nieber, J.; Vondracek, B.; Perry, J.; Magner, J.

    2005-01-01

    Recent research has emphasized the importance of using physical, chemical, and biological indicators of stream health for diagnosing impaired watersheds and their receiving water bodies. A multidisciplinary team at the University of Minnesota is carrying out research to develop a stream classification system for Total Maximum Daily Load (TMDL) assessment. Funding for this research is provided by the United States Environmental Protection Agency and the Minnesota Pollution Control Agency. One objective of the research study involves investigating the relationships between indicators of stream health and localized stream characteristics. Measured data from Minnesota streams collected by various government and non-government agencies and research institutions have been obtained for the research study. Innovative Geographic Information Systems tools developed by the Environmental Science Research Institute and the University of Texas are being utilized to combine and organize the data. Simple linear relationships between index of biological integrity (IBI) and channel slope, two-year stream flow, and drainage area are presented for the Redwood River and the Snake River Basins. Results suggest that more rigorous techniques are needed to successfully capture trends in IBI scores. Additional analyses will be done using multiple regression, principal component analysis, and clustering techniques. Uncovering key independent variables and understanding how they fit together to influence stream health are critical in the development of a stream classification for TMDL assessment.

  4. ADAPTIVE STREAMING OVER HTTP (DASH UNTUK APLIKASI VIDEO STREAMING

    Directory of Open Access Journals (Sweden)

    I Made Oka Widyantara

    2015-12-01

    Full Text Available This paper aims to analyze Internet-based streaming video service in the communication media with variable bit rates. The proposed scheme on Dynamic Adaptive Streaming over HTTP (DASH using the internet network that adapts to the protocol Hyper Text Transfer Protocol (HTTP. DASH technology allows a video in the video segmentation into several packages that will distreamingkan. DASH initial stage is to compress the video source to lower the bit rate video codec uses H.26. Video compressed further in the segmentation using MP4Box generates streaming packets with the specified duration. These packages are assembled into packets in a streaming media format Presentation Description (MPD or known as MPEG-DASH. Streaming video format MPEG-DASH run on a platform with the player bitdash teritegrasi bitcoin. With this scheme, the video will have several variants of the bit rates that gave rise to the concept of scalability of streaming video services on the client side. The main target of the mechanism is smooth the MPEG-DASH streaming video display on the client. The simulation results show that the scheme based scalable video streaming MPEG-DASH able to improve the quality of image display on the client side, where the procedure bufering videos can be made constant and fine for the duration of video views

  5. Relation between Streaming Potential and Streaming Electrification Generated by Streaming of Water through a Sandwich-type Cell

    OpenAIRE

    Maruyama, Kazunori; Nikaido, Mitsuru; Hara, Yoshinori; Tanizaki, Yoshie

    2012-01-01

    Both streaming potential and accumulated charge of water flowed out were measured simultaneously using a sandwich-type cell. The voltages generated in divided sections along flow direction satisfied additivity. The sign of streaming potential agreed with that of streaming electrification. The relation between streaming potential and streaming electrification was explained from a viewpoint of electrical double layer in glass-water interface.

  6. Evaluation of radionuclide induced damage in marine invertebrates

    International Nuclear Information System (INIS)

    Hagger, Josephine Anne

    2002-01-01

    Limited studies have been carried out to assess the potential effects of ionising radiation on marine organisms. Therefore the general aims of this thesis were, (a) to assess the cytotoxic, genotoxic and developmental effects of ionising radiation on the embryo-larvae of two ecologically relevant marine invertebrates Mytilus edulis and Platynereis dumerilii, (2) to assess the effects of an environmentally relevant cocktail of radionuclides (3) to monitor the potential impact of radiation in the natural environment and finally (4) attempt to predict the potential effects of radiation at a population level. Following validation of developmental stages and mammalian based cytotoxic and genotoxic assays, chromosomal aberrations (Cabs), sister chromatid exchanges (SCEs) and proliferation rate index (PRI), on the embryo-larvae of M. edulis and P. dumerilii, the embryo-larvae stages were exposed to a reference radionuclide, tritium, (0.37,3.7,37 and 370 kBq/ml). Low doses of radiation delivered by tritium were shown to be detrimental to the development of embryo-larvae with an increase in abnormality for P. dumerilii and an increase in mortality for M. edulis. Tritium increased the induction of chromosomal aberrations and sister chromatid exchanges, in exposed embryo-larvae, indicating that tritium is potentially genotoxic. Cytotoxic effects (reduction in the cell proliferation rate) were also observed following exposure of embryo-larvae to tritium. In collaboration with the Royal Devonport Dockyard (DML) investigations on the cytotoxic, genotoxic and developmental effects of a cocktail of radionuclides (radioactive liquid waste diluted to 1.8,3.2, 5.6, 18%) were carried out. All embryo-larvae exposed to 18% radioactive waste were dead within 24h. Both species exhibited increased abnormality, SCEs and Cabs and a reduction in PRI in dilutions 1.8-5.6%. In general M. edulis appeared to be more sensitive to ionising radiation than P. dumerilii embryo-larvae. Following

  7. Human impacts to mountain streams

    Science.gov (United States)

    Wohl, Ellen

    2006-09-01

    Mountain streams are here defined as channel networks within mountainous regions of the world. This definition encompasses tremendous diversity of physical and biological conditions, as well as history of land use. Human effects on mountain streams may result from activities undertaken within the stream channel that directly alter channel geometry, the dynamics of water and sediment movement, contaminants in the stream, or aquatic and riparian communities. Examples include channelization, construction of grade-control structures or check dams, removal of beavers, and placer mining. Human effects can also result from activities within the watershed that indirectly affect streams by altering the movement of water, sediment, and contaminants into the channel. Deforestation, cropping, grazing, land drainage, and urbanization are among the land uses that indirectly alter stream processes. An overview of the relative intensity of human impacts to mountain streams is provided by a table summarizing human effects on each of the major mountainous regions with respect to five categories: flow regulation, biotic integrity, water pollution, channel alteration, and land use. This table indicates that very few mountains have streams not at least moderately affected by land use. The least affected mountainous regions are those at very high or very low latitudes, although our scientific ignorance of conditions in low-latitude mountains in particular means that streams in these mountains might be more altered than is widely recognized. Four case studies from northern Sweden (arctic region), Colorado Front Range (semiarid temperate region), Swiss Alps (humid temperate region), and Papua New Guinea (humid tropics) are also used to explore in detail the history and effects on rivers of human activities in mountainous regions. The overview and case studies indicate that mountain streams must be managed with particular attention to upstream/downstream connections, hillslope

  8. Chironomus larvae (Chironomidae: Diptera as water quality indicators along an environmental gradient in a neotropical urban stream

    Directory of Open Access Journals (Sweden)

    Nadja Gomes Machado

    2015-04-01

    Full Text Available Anthropogenic interference in urban lotic systems is a factor affecting the biota of waterbodies. Aquatic macro invertebrates are an important food source for fish and are valuable indicators of water quality. The objective of this work was to study Chironomus larvae (Chironomidae: Diptera distribution along an environmental gradient in Barbado Stream, Cuiabá, MT, Brazil. No individual Chironomus was found in the springs of Barbado Stream, which may indicate preservation of the area. During the study period, we found 40.3 and 94.4 individuals/m2 at points 3 and 4 (low course, respectively. There is eutrophication in these sites due to domestic sewage discharges, indicating low quality water. The Barbado Stream needs restoration projects that include an awareness of the residents of their neighborhood’s environmental importance, and investments in the sanitation sector to prioritize the collection and treatment of wastewater and solid waste collection.

  9. A cross-continental comparison of the effects of flow intermittence on benthic invertebrate assemblages

    Science.gov (United States)

    Although temporary rivers are widespread freshwater systems, they have been poorly studied by ecologists and are largely ignored in water management plans, practices and policies. If the effects of dry events on benthic invertebrates have been reported individually from different...

  10. The estimation of sample size required in chemical limnology and autecology of shelled invertebrates

    National Research Council Canada - National Science Library

    Delorme, L. D; El-Shaarawi, A. H

    1978-01-01

    .... The confidence coefficient is 1 - 2alpha. In the field of chemical limnology and autecology of shelled invertebrates, most chemical parameters must be transformed to obtain a normal distribution...

  11. Invertebrate populations of the deciduous forest: fluctuations and relations to weather

    National Research Council Canada - National Science Library

    Kendeigh, S. Charles

    1979-01-01

    The major objectives of the present study are to analyze (a) the composition and relative population sizes of the larger invertebrate fauna of relatively undisturbed, near-virgin, stands of deciduous forest, (b...

  12. Chemosynthetic symbionts of marine invertebrate animals are capable of nitrogen fixation

    NARCIS (Netherlands)

    Petersen, J.M.; Kemper, A.; Gruber-Vodicka, H.R.; Cardini, U.; van der Geest, M.; Kleiner, M.; Bulgheresi, S.; Mußmann, M; Herbold, C.W.; Seah, B.K.B.; Antony, C.P.; Liu, D.; Belitz, A.; Weber, M.

    2016-01-01

    Chemosynthetic symbioses are partnerships between invertebrate animals and chemosynthetic bacteria. The latter are theprimary producers, providing most of the organic carbon needed for the animal host’s nutrition. We sequenced genomesof the chemosynthetic symbionts from the lucinid bivalve Loripes

  13. Marine Invertebrate Larvae Associated with Symbiodinium: A Mutualism from the Start?

    KAUST Repository

    Mies, Miguel; Sumida, Paulo Y. G.; Radecker, Nils; Voolstra, Christian R.

    2017-01-01

    Symbiodinium are dinoflagellate photosynthetic algae that associate with a diverse array of marine invertebrates, and these relationships are comprehensively documented for adult animal hosts. Conversely, comparatively little is known about

  14. Estimating escapement of fish and invertebrates in a Danish anchor seine

    DEFF Research Database (Denmark)

    Noack, Thomas; Madsen, Niels; Mieske, Bernd

    2017-01-01

    The codend is generally presumed to be the place where the main selectivity of fish occurs in towed fishing gears, but other parts of the net have been found to contribute to the selectivity process of several invertebrate species. This means that conventional selectivity or survival studies may......) invertebrates from the forward parts of the seine net. For seven species of demersal fish, most fish escaped through the lower panel close to the codend. All invertebrate species were found in higher numbers in the collecting bags than in the codend where many organisms escaped in the lower panel of the wings...... or the belly. Mean levels of visible damage ranged from 1.00 to 3.25 for collected invertebrates and were similar for all gear parts. Common starfish (Asterias rubens), however, showed highest damage in the extension part of the net....

  15. Species List of Alaskan Birds, Mammals, Fish, Amphibians, Reptiles, and Invertebrates. Alaska Region Report Number 82.

    Science.gov (United States)

    Taylor, Tamra Faris

    This publication contains a detailed list of the birds, mammals, fish, amphibians, reptiles, and invertebrates found in Alaska. Part I lists the species by geographical regions. Part II lists the species by the ecological regions of the state. (CO)

  16. Responses of invertebrates to temperature and water stress: A polar perspective.

    Science.gov (United States)

    Everatt, Matthew J; Convey, Pete; Bale, Jeffrey S; Worland, M Roger; Hayward, Scott A L

    2015-12-01

    As small bodied poikilothermic ectotherms, invertebrates, more so than any other animal group, are susceptible to extremes of temperature and low water availability. In few places is this more apparent than in the Arctic and Antarctic, where low temperatures predominate and water is unusable during winter and unavailable for parts of summer. Polar terrestrial invertebrates express a suite of physiological, biochemical and genomic features in response to these stressors. However, the situation is not as simple as responding to each stressor in isolation, as they are often faced in combination. We consider how polar terrestrial invertebrates manage this scenario in light of their physiology and ecology. Climate change is also leading to warmer summers in parts of the polar regions, concomitantly increasing the potential for drought. The interaction between high temperature and low water availability, and the invertebrates' response to them, are therefore also explored. Copyright © 2014 Elsevier Ltd. All rights reserved.

  17. The importance of spatial variation of benthic invertebrates for the ecological assessment of European lakes

    DEFF Research Database (Denmark)

    Solimini, Angelo G.; Sandin, Leif Leonard

    2012-01-01

    variability. However, littoral and profundal invertebrate communities are constrained by different drivers of change and may respond unevenly to distinct human disturbances. How human disturbances determined by different pressures interact in modifying the distribution of benthic invertebrate species......, funded by the European Union under the 7th Framework Programme), we collated several case studies with the aim to increase our understanding of basic sources of spatial variation of invertebrate assemblages. The set of papers includes a variety of different European lakes, habitat types and human...... pressures from the Nordic, Central, Atlantic, Alpine and Mediterranean regions. All papers have an obvious applied objective and suggest which factors need to be considered when designing invertebrate-based classification tools....

  18. Diversity and abundance of invertebrate epifaunal assemblages associated with gorgonians are driven by colony attributes

    KAUST Repository

    Curdia, Joao; Carvalho, Susana; Pereira, Fá bio R.; Guerra-Garcí a, José Manuel; Santos, Miguel Neves Dos; Cunha, Marina R.

    2015-01-01

    The present study aimed to explicitly quantify the link between the attributes of shallow-water gorgonian colonies (Octocorallia: Alcyonacea) and the ecological patterns of associated non-colonial epifaunal invertebrates. Based on multiple

  19. Chemical Compounds Toxic to Invertebrates Isolated from Marine Cyanobacteria of Potential Relevance to the Agricultural Industry

    Science.gov (United States)

    Essack, Magbubah; Alzubaidy, Hanin S.; Bajic, Vladimir B.; Archer, John A. C.

    2014-01-01

    In spite of advances in invertebrate pest management, the agricultural industry is suffering from impeded pest control exacerbated by global climate changes that have altered rain patterns to favour opportunistic breeding. Thus, novel naturally derived chemical compounds toxic to both terrestrial and aquatic invertebrates are of interest, as potential pesticides. In this regard, marine cyanobacterium-derived metabolites that are toxic to both terrestrial and aquatic invertebrates continue to be a promising, but neglected, source of potential pesticides. A PubMed query combined with hand-curation of the information from retrieved articles allowed for the identification of 36 cyanobacteria-derived chemical compounds experimentally confirmed as being toxic to invertebrates. These compounds are discussed in this review. PMID:25356733

  20. Six decades of change in pollution and benthic invertebrate biodiversity in a southern New England estuary

    Science.gov (United States)

    Pollution has led to a decline of benthic invertebrate biodiversity of Narragansett Bay, raising questions about effects on ecosystem functions and services including shellfish production, energy flow to fishes, and biogeochemical cycles. Changes in community composition and taxo...

  1. Tube-dwelling invertebrates: tiny ecosystem engineers have large effects in lake ecosystems

    NARCIS (Netherlands)

    Hölker, Franz; Vanni, Michael J.; Kuiper, Jan J.; Meile, Christof; Grossart, Hans-Peter; Stief, Peter; Adrian, Rita; Lorke, Andreas; Dellwig, Olaf; Brand, Andreas; Hupfer, Michael; Mooij, Wolf M.; Nützmann, Gunnar; Lewandowski, Jörg

    2015-01-01

    There is ample evidence that tube-dwelling invertebrates such as chironomids significantly alter multiple important ecosystem functions, particularly in shallow lakes. Chironomids pump large water volumes, and associated suspended and dissolved substances, through the sediment and thereby compete

  2. Sensitivity of Coastal Environments and Wildlife to Spilled Oil: Hudson River: INVERT (Invertebrate Polygons)

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — This data set contains sensitive biological resource data for marine and estuarine invertebrate species for the Hudson River. Vector polygons in this data set...

  3. Efficacy Testing of Pesticides used for Invertebrate Pests and Fire Ants

    Science.gov (United States)

    Event page for the upcoming Federal Insecticide, Fungicide, and Rodenticide Act (FIFRA) Scientific Advisory Panel (SAP) meeting on Efficacy Testing of Pesticides used for Invertebrate Pests and Fire Ants

  4. 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...

  5. Chemical Compounds Toxic to Invertebrates Isolated from Marine Cyanobacteria of Potential Relevance to the Agricultural Industry

    KAUST Repository

    Essack, Magbubah

    2014-10-29

    In spite of advances in invertebrate pest management, the agricultural industry is suffering from impeded pest control exacerbated by global climate changes that have altered rain patterns to favour opportunistic breeding. Thus, novel naturally derived chemical compounds toxic to both terrestrial and aquatic invertebrates are of interest, as potential pesticides. In this regard, marine cyanobacterium-derived metabolites that are toxic to both terrestrial and aquatic invertebrates continue to be a promising, but neglected, source of potential pesticides. A PubMed query combined with hand-curation of the information from retrieved articles allowed for the identification of 36 cyanobacteria-derived chemical compounds experimentally confirmed as being toxic to invertebrates. These compounds are discussed in this review.

  6. Marine Benthic Invertebrates in Mamala Bay, Oahu, Hawaii 1994 (NODC Accession 9900151)

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — Planktonic larval stages of many benthic marine invertebrates are especially susceptible to environmental stress, such as the presence of pollution. Recruitment of...

  7. Sensitivity of Coastal Environments and Wildlife to Spilled Oil: Northwest Arctic, Alaska: INVERT (Invertebrate Polygons)

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — This data set contains sensitive biological resource data for marine and estuarine invertebrate species in Northwest Arctic, Alaska. Vector polygons in this data set...

  8. Sensitivity of Coastal Environments and Wildlife to Spilled Oil: Florida Panhandle: INVERTPT (Invertebrate Points)

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — This data set contains sensitive biological resource data for threatened/endangered invertebrate species for the Florida Panhandle. Vector points in this data set...

  9. Sensitivity of Coastal Environments and Wildlife to Spilled Oil: Mississippi: INVERT (Invertebrate Polygons)

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — This data set contains sensitive biological resource data for marine, estuarine, and brackish water invertebrate species in Mississippi. Vector polygons in this data...

  10. Rhode Island, Connecticut, New York, and New Jersey ESI: INVERT (Invertebrate Polygons)

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — This data set contains sensitive biological resource data for marine, estuarine, and terrestrial invertebrate species in coastal Rhode Island, Connecticut, New York,...

  11. Sensitivity of Coastal Environments and Wildlife to Spilled Oil: Central California: INVERT (Invertebrate Polygons)

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — This data set contains sensitive biological resource data for marine, intertidal/subtidal, and terrestrial invertebrate species in Central California. Vector...

  12. Rhode Island, Connecticut, New York, and New Jersey ESI: INVERTPT (Invertebrate Points)

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — This data set contains sensitive biological resource data for rare terrestrial invertebrates in coastal Rhode Island, Connecticut, New York, and New Jersey. Vector...

  13. Chemical Compounds Toxic to Invertebrates Isolated from Marine Cyanobacteria of Potential Relevance to the Agricultural Industry

    KAUST Repository

    Essack, Magbubah; Alzubaidy, Hanin S.; Bajic, Vladimir B.; Archer, John A.C.

    2014-01-01

    In spite of advances in invertebrate pest management, the agricultural industry is suffering from impeded pest control exacerbated by global climate changes that have altered rain patterns to favour opportunistic breeding. Thus, novel naturally derived chemical compounds toxic to both terrestrial and aquatic invertebrates are of interest, as potential pesticides. In this regard, marine cyanobacterium-derived metabolites that are toxic to both terrestrial and aquatic invertebrates continue to be a promising, but neglected, source of potential pesticides. A PubMed query combined with hand-curation of the information from retrieved articles allowed for the identification of 36 cyanobacteria-derived chemical compounds experimentally confirmed as being toxic to invertebrates. These compounds are discussed in this review.

  14. Sensitivity of Coastal Environments and Wildlife to Spilled Oil: New Hampshire: INVERT (Invertebrate Polygons)

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — This data set contains sensitive biological resource data for marine, and estuarine invertebrate species in New Hampshire. Vector polygons in this data set represent...

  15. Sensitivity of Coastal Environments and Wildlife to Spilled Oil: Upper Coast of Texas: INVERT (Invertebrate Polygons)

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — This data set contains sensitive biological resource data for marine and estuarine invertebrate species for the Upper Coast of Texas. Vector polygons in this data...

  16. Sensitivity of Coastal Environments and Wildlife to Spilled Oil: South Florida: INVERT (Invertebrate Polygons)

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — This data set contains sensitive biological resource data for marine and estuarine invertebrate species in South Florida. Vector polygons in this data set represent...

  17. Sensitivity of Coastal Environments and Wildlife to Spilled Oil: Florida Panhandle: INVERT (Invertebrate Polygons)

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — This data set contains sensitive biological resource data for marine, estuarine, and freshwater (limited to threatened/endangered/rare) invertebrate species for the...

  18. Sensitivity of Coastal Environments and Wildlife to Spilled Oil: North Carolina: INVERT (Invertebrate Polygons)

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — This data set contains sensitive biological resource data for marine and estuarine invertebrate species in North Carolina. Vector polygons in this data set represent...

  19. Sensitivity of Coastal Environments and Wildlife to Spilled Oil: Northern California: INVERT (Invertebrate Polygons)

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — This data set contains sensitive biological resource data for marine, estuarine, freshwater, and terrestrial invertebrate species in Northern California. Vector...

  20. Predation Risk versus Pesticide Exposure: Consequences of Fear and Loathing in the Life of Stream Shredders

    Science.gov (United States)

    Pestana, J. T.; Baird, D. J.; Soares, A. M.

    2005-05-01

    Stream invertebrates are exposed to complex stressor regimes including both biotic and abiotic factors. Species living in streams in agricultural landscapes are often subjected to episodic or continuous exposures to low levels of agrochemicals, which may approach or exceed specific substance guidelines. Sublethal effects of pesticides may result in direct effects on organisms (e.g. reduced physiological performance), which may in turn contribute to indirect effects relating to survival (e.g. increased predation risk). Here, we investigate the possibility that predator-release kairomones can act additively with low-level pesticide exposure to reduce physiological performance and survival of stream invertebrates in previously unforeseen ways. Feeding, metabolic and behavioural responses of two shredder insects, the North American stonefly Pteronarcys comstockii and the European caddisfly Sericostoma vittatum were measured under exposure to the insecticide imidacloprid at different levels of indirect predation stress using predator-release kairomones from Brown Trout (Salmo trutta). Pteronarcys feeding was measured in terms of mass of naturally conditioned alder leaf discs consumed over a 6-day and 10 -day period in animals held in cages in stream mesocosms. Pteronarcys feeding was impaired at 1 ppb in the 6-day trial and at 0,5 ppb in the 10-day trial relatively to unexposed controls. Metabolic rate was measured in the lab in terms of oxygen consumption of Pteronarcys. Animals exposed to 0.5 and 1 ppb imidacloprid showed elevated respiratory rates compared to controls. Laboratory experiments with Sericostoma, currently in progress, are examining the separate and combined effects of imidacloprid and predator kairomone on similar endpoints. These preliminary results are discussed in relation to the development of the Mechanistic Unifying Stressor Effects (MUSE) model which can be used to predict combined ecological effects of multiple stressors at the population level.