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Sample records for benthic invertebrates structure

  1. Research regarding the changes that occur in the structure of benthic macro invertebrates communities as a result of anthropogenic activities

    Directory of Open Access Journals (Sweden)

    Anca-Andreea Marin

    2016-05-01

    Full Text Available An important role in the monitoring of the water quality is represented by the benthic macro invertebrates. They are a key component in the transfer of matter and energy in the aquatic ecosystems. In May 2015, 20 quantitative samples of benthic sample were collected at different seasons in the Bega River water. Samples were collected from the upstream, middle and downstream of Timisoara city. The aim of this paper is to identify the changes that occur in the structure of benthic macro invertebrates communities due to anthropogenic activities. Once the identification of  saprobionte organisms has done, it have been performed the density, abundance and frequency of the sample. Based on these values, we can say that the upstream segment waters falls into the category of superior quality compared to the waters of the central segment, especially in the downstream segment.

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

    International Nuclear Information System (INIS)

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

  3. Benthic invertebrates structure in wetlands of a tributary of the middle Parana River (Argentina) affected by hydrologic and anthropogenic disturbances.

    Science.gov (United States)

    Marchese, Mercedes R; Rodriguez, Alba R; Pave, Paola J; Carignano, Maria R

    2008-05-01

    The present study was aimed at analyzing chromium concentrations in water column and bottom sediments in the main channel of Northern Salado River (tributary of Middle Parana River) and its floodplain. The main changes caused by human activities and hydrological disturbances on benthic invertebrate structure were also analyzed. Sediment concentrations of the reference area varied between 44.2 and 97.1 microg Crg(-1) (dw), and in the impacted zone, between 85.5 and 209 microg Cr g(-1) (dw) reaching the highest values in the wetland floodplain. Alfa, beta and gamma diversities in the reference section have been 33, 9 and 66 species, and in the disturbed section, they have been 37, 8.33 and 74 species, respectively The species dominant in the disturbed habitats were characterized by a small body size and short life cycles, as the species of olig chaetes Naidinae. The extreme flooding produced a rejuvenation of the area with the consequent physical re-structuration produced by flooding, showing: a marked decrease in chromium levels in sediments and in organic matter content, which allowed the colonization of insects (Ephemeroptera and Trichoptera). PMID:18972689

  4. Progress research report, 27 June, 1983, benthic invertebrate studies

    International Nuclear Information System (INIS)

    The benthic ecological research at site W-N for the Low Level Waste Ocean Disposal Program is oriented towards characterizing the invertebrate community associated with the seafloor and towards understanding the links within the benthic food web. Stomach analyses of benthic-feeding fishes reveal a varied diet of benthic and peloagio-benthic forms. From the trawl samples of megafauna, the basic community structure is similar to other deep-sea areas with echinoderms as the predominant forms. For the macrofauna, polychaete worms comprise the dominant taxonomic group. Very little is known about the fauna at area W-N on the species level. Such data will help answer the question of whether this community is characteristic of the continental slope base or is a transition between continentally-influenced communities and those in the central portion of ocean basins. Environmental differences within the area suggest that the benthic fauna should also vary in composition and abundance. 19 references, 7 figures, 5 tables

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

    Science.gov (United States)

    Frelik, Anna; Pakulnicka, Joanna

    2015-10-01

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

  6. A comparison of selected diversity, similarity, and biotic indices for detecting changes in benthic-invertebrate community structure and stream quality

    Science.gov (United States)

    Lydy, M.J.; Crawford, Charles G.; Frey, J.W.

    2000-01-01

    Implementation of advanced wastewater treatment at the two municipal wastewater-treatment plants for Indianapolis, Indiana, resulted in substantial improvement in the quality of the receiving stream and significant changes in the benthic-invertebrate community. Diversity, similarity, and biotic indices were compared to determine which indices best reflected changes in the composition of the biota in the river. None of the indices perfectly reflected the changes in river quality or community structure. Similarity indices, especially percentage similarity, exhibit the most promise of the three classes of indices. Diversity indices were least useful, wrongly indicating that water quality deteriorated after the upgrade of the wastewater-treatment plants. The most descriptive tool in analyzing the data was the percentage of Ephemeroptera, Plecoptera, and Trichoptera (EPT) taxa present. Using a mixture of indices and other analytical tools, such as EPT, in the analysis of biological data will ensure the most effective investigations of water quality.

  7. Methods for collecting benthic invertebrate samples as part of the National Water-Quality Assessment Program

    Science.gov (United States)

    Cuffney, Thomas F.; Gurtz, Martin E.; Meador, Michael R.

    1993-01-01

    Benthic invertebrate communities are evaluated as part of the ecological survey component of the U.S. Geological Survey's National Water-Quality Assessment Program. These biological data are collected along with physical and chemical data to assess water-quality conditions and to develop an understanding of the factors that affect water-quality conditions locally, regionally, and nationally. The objectives of benthic invertebrate community characterizations are to (1) develop for each site a list of tax a within the associated stream reach and (2) determine the structure of benthic invertebrate communities within selected habitats of that reach. A nationally consistent approach is used to achieve these objectives. This approach provides guidance on site, reach, and habitat selection and methods and equipment for qualitative multihabitat sampling and semi-quantitative single habitat sampling. Appropriate quality-assurance and quality-control guidelines are used to maximize the ability to analyze data within and among study units.

  8. Global Warming and Mass Mortalities of Benthic Invertebrates in the Mediterranean Sea

    OpenAIRE

    Irene Rivetti; Simonetta Fraschetti; Piero Lionello; Enrico Zambianchi; Ferdinando Boero

    2014-01-01

    Satellite data show a steady increase, in the last decades, of the surface temperature (upper few millimetres of the water surface) of the Mediterranean Sea. Reports of mass mortalities of benthic marine invertebrates increased in the same period. Some local studies interpreted the two phenomena in a cause-effect fashion. However, a basin-wide picture of temperature changes combined with a systematic assessment on invertebrate mass mortalities was still lacking. Both the thermal structure of ...

  9. A newly developed dispersal metric indicates the succession of benthic invertebrates in restored rivers.

    Science.gov (United States)

    Li, Fengqing; Sundermann, Andrea; Stoll, Stefan; Haase, Peter

    2016-11-01

    Dispersal capacity plays a fundamental role in the riverine benthic invertebrate colonization of new habitats that emerges following flash floods or restoration. However, an appropriate measure of dispersal capacity for benthic invertebrates is still lacking. The dispersal of benthic invertebrates occurs mainly during the aquatic (larval) and aerial (adult) life stages, and the dispersal of each stage can be further subdivided into active and passive modes. Based on these four possible dispersal modes, we first developed a metric (which is very similar to the well-known and widely used saprobic index) to estimate the dispersal capacity for 802 benthic invertebrate taxa by incorporating a weight for each mode. Second, we tested this metric using benthic invertebrate community data from a) 23 large restored river sites with substantial improvements of river bottom habitats dating back 1 to 10years, b) 23 unrestored sites very close to the restored sites, and c) 298 adjacent surrounding sites (mean±standard deviation: 13.0±9.5 per site) within a distance of up to 5km for each restored site in the low mountain and lowland areas of Germany. We hypothesize that our metric will reflect the temporal succession process of benthic invertebrate communities colonizing the restored sites, whereas no temporal changes are expected in the unrestored and surrounding sites. By applying our metric to these three river treatment categories, we found that the average dispersal capacity of benthic invertebrate communities in the restored sites significantly decreased in the early years following restoration, whereas there were no changes in either the unrestored or the surrounding sites. After all taxa had been divided into quartiles representing weak to strong dispersers, this pattern became even more obvious; strong dispersers colonized the restored sites during the first year after restoration and then significantly decreased over time, whereas weak dispersers continued to increase

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

    OpenAIRE

    Bennett, Barbara Loraine Jr.

    1998-01-01

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

  11. Benthic invertebrates that form habitat on deep banks off southern California, with special reference to deep sea coral

    OpenAIRE

    Brian N. Tissot; Mary M Yoklavich; Love, Milton S.; York, Keri; Amend, Mark

    2006-01-01

    There is increasing interest in the potential impacts that fishing activities have on megafaunal benthic invertebrates occurring in continental shelf and slope ecosystems. We examined how the structure, size, and high-density aggregations of invertebrates provided structural relief for fishes in continental shelf and slope ecosystems off southern California. We made 112 dives in a submersible at 32−320 m water depth, surveying a variety of habitats from high-relief rock to flat sand and mud. ...

  12. Global warming and mass mortalities of benthic invertebrates in the Mediterranean Sea.

    Directory of Open Access Journals (Sweden)

    Irene Rivetti

    Full Text Available Satellite data show a steady increase, in the last decades, of the surface temperature (upper few millimetres of the water surface of the Mediterranean Sea. Reports of mass mortalities of benthic marine invertebrates increased in the same period. Some local studies interpreted the two phenomena in a cause-effect fashion. However, a basin-wide picture of temperature changes combined with a systematic assessment on invertebrate mass mortalities was still lacking. Both the thermal structure of the water column in the Mediterranean Sea over the period 1945-2011 and all documented invertebrate mass mortality events in the basin are analysed to ascertain if: 1- documented mass mortalities occurred under conditions of positive temperature trends at basin scale, and 2- atypical thermal conditions were registered at the smaller spatial and temporal scale of mass mortality events. The thermal structure of the shallow water column over the last 67 years was reconstructed using data from three public sources: MEDAR-MEDATLAS, World Ocean Database, MFS-VOS programme. A review of the mass mortality events of benthic invertebrates at Mediterranean scale was also carried out. The analysis of in situ temperature profiles shows that the Mediterranean Sea changed in a non-homogeneous fashion. The frequency of mass mortalities is increasing. The areas subjected to these events correspond to positive thermal anomalies. Statistically significant temperature trends in the upper layers of the Mediterranean Sea show an increase of up to 0.07°C/yr for a large fraction of the basin. Mass mortalities are consistent with both the temperature increase at basin scale and the thermal changes at local scale, up to 5.2°C. Our research supports the existence of a causal link between positive thermal anomalies and observed invertebrate mass mortalities in the Mediterranean Sea, invoking focused mitigation initiatives in sensitive areas.

  13. 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...

  14. Biogeographical Patterns of Marine Benthic Invertebrates Along the Atlantic Coast of the Northeastern USA

    Science.gov (United States)

    Aim Examine the biogeography of marine benthic invertebrates of the Atlantic coast of the northeastern USA, compare the results to historical biogeographic studies, define physical-chemical factors affecting species distributions, and provide biogeographic information needed to ...

  15. A study on the biodiversity of benthic invertebrates in the waters of Seogwipo, Jeju Island, Korea

    OpenAIRE

    In-Young Cho; Dong-Won Kang; Jisoon Kang; Hosung Hwang; Jeong-Hye Won; Woon Kee Paek; Su-Yuan Seo

    2014-01-01

    The biodiversity of benthic invertebrates in the intertidal and subtidal regions of Gapado, Beomseom, and Munseom islets was surveyed twice in May and September 2013 to study the state of biodiversity in Seogwipo, Jeju Island. As a result, a total of 77 species, 46 families, 25 orders, 14 classes, and nine phyla of benthic invertebrates were found. The species which were found, by taxon, consisted of the following: 26 species of Cnidaria (34%), 24 species of Mollusca (31%), seven species of C...

  16. Regulation of nitrous oxide emission associated with benthic invertebrates

    DEFF Research Database (Denmark)

    Stief, Peter; Schramm, Andreas

    2010-01-01

    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......- availability and (iii) the quantitative relationship between direct and indirect N2O emission. 3. Larvae of the mayfly Ephemera danica, which prefer a bacteria-rich detritus diet, emitted N2O at rates of up to 90 pmol Ind.-1 h-1 under in situ conditions and 550 pmol Ind.-1 h-1 under laboratory conditions....... In contrast, larvae of the alderfly Sialis lutaria, which prefer a bacteria-poor carnivorous diet, emitted N2O at invariably low rates of 0–20 pmol Ind.-1 h-1. The N2O emission rate of E. danica larvae was positively correlated with seasonally changing factors (body size, temperature and NO3- availability...

  17. Species Diversity of Macro-benthic Invertebrates in Mangrove and Seagrass Ecosystems of Eastern Bohol, Philippines

    Directory of Open Access Journals (Sweden)

    Marichu C. Libres

    2015-12-01

    Full Text Available Descriptive survey method through actual resource assessment was conducted to determine the species diversity of macro-benthic invertebrates in the mangrove forest and seagrass beds of Eastern Bohol, Philippines namely: Anda, Candijay, Mabini, and Ubay. The 4 representative sites were chosen through random sampling. In each municipality, the researcher selected a representative area wherein 3 transects were laid perpendicular to the shoreline. The assessment in each transect covered a strip of 4 m by 50 m. All macro-benthic invertebrates intercepted within 4-meter to the left and right of the transect line were identified, counted and listed in a slate board. The data gathered were subjected to Shannon-Weiner Index and Kruskal Wallis Test. In mangrove forests, results revealed that Anda got the highest species diversity index of 1.66 with 11 species. The lowest value which is 1.15 was recorded in Candijay having only five macro-benthic invertebrate species. In the 4 municipalities, a total of 12 species representing 3 phyla were identified. In seagrass beds, 19 taxa of macro-benthic invertebrates were recorded belonging to three phyla. Based on the findings, the researcher concluded that macro-benthic invertebrates in eastern part of Bohol is diverse both in mangrove forests and seagrass beds. Moreover, there is no significant difference in the species diversity among the four representative sites.

  18. 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

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

    International Nuclear Information System (INIS)

    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

  20. Baseline ecological risk assessment of the Calcasieu Estuary, Louisiana: 3. An evaluation of the risks to benthic invertebrates associated with exposure to contaminated sediments

    Science.gov (United States)

    MacDonald, Donald D.; Ingersoll, Christopher G.; Kemble, Nile E.; Smorong, Dawn E.; Sinclair, Jesse A.; Lindskoog, Rebekka; Gaston, Gary; Sanger, Denise; Carr, R. Scott; Biedenbach, James; Gouguet, Ron; Kern, John; Shortelle, Ann; Field, L. Jay; Meyer, John

    2011-01-01

    The sediments in the Calcasieu Estuary are contaminated with a wide variety of chemicals of potential concern (COPCs), including heavy metals, polycyclic aromatic hydrocarbons, polychlorinated biphenyls, phthalates, chlorinated benzenes, and polychlorinated dibenzo-p-dioxins and dibenzofurans. The sources of these COPCs include both point and non-point source discharges. As part of a baseline ecological risk assessment, the risks to benthic invertebrates posed by exposure to sediment-associated COPCs were assessed using five lines of evidence, including whole-sediment chemistry, pore-water chemistry, whole-sediment toxicity, pore-water toxicity, and benthic invertebrate community structure. The results of this assessment indicated that exposure to whole sediments and/or pore water from the Calcasieu Estuary generally posed low risks to benthic invertebrate communities (i.e., risks were classified as low for 68% of the sampling locations investigated). However, incremental risks to benthic invertebrates (i.e., compared with those associated with exposure to conditions in reference areas) were indicated for 32% of the sampling locations within the estuary. Of the three areas of concern (AOCs) investigated, the risks to benthic invertebrates were highest in the Bayou d'Inde AOC; risks were generally lower in the Upper Calcasieu River AOC and Middle Calcasieu River AOC. The areas showing the highest risks to sediment-dwelling organisms were generally located in the vicinity of point source discharges of COPCs. These results provided risk managers with the information required to make decisions regarding the need for remedial actions at the site.

  1. Nearshore marine benthic invertebrates moving north along the U.S. Atlantic coast

    Science.gov (United States)

    Numerous species have shifted their ranges north in response to global warming. We examined 21 years (1990-2010) of marine benthic invertebrate data from the National Coastal Assessment’s monitoring of nearshore waters along the US Atlantic coast. Data came from three bioge...

  2. Benthic Macro Invertebrate Fauna and Physico-chemical Parameters in Okpoka Creek Sediments, Niger Delta, Nigeria

    OpenAIRE

    J.F.N. Abowei

    2009-01-01

    The benthic macro invertebrate fauna and physico-chemical parameters in Okpoka creek sedimentswas studied for a period of one year. A total of nineteen (19) species(Ophidonais serpentina, Arenicola marina,Eunice harassi, Marphysa sanguinea, Capitella capitata, Notomastus latrella, Notomastus tenuis, Glyceracapitata, Glycera convoluta, Nereis diversicolor, Nereis pelagica, Nereis virens, Nephthys hombergi,Nototropis swamidami, Cliberanus cooci, Iphinoe tripanosa, Chironomus ablabiesmia, Tellin...

  3. Bioaccumulation of sediment-bound Cr-51, Ni-63 and C-14 by benthic invertebrates

    International Nuclear Information System (INIS)

    Sediments in many areas of the Baltic Sea are highly contaminated with particle-reactive trace metals and/or radionuclides. These may be re-mobilised into aquatic food chains by bioaccumulation into benthic organisms. In this study, we examined and compared assimilation efficiencies and bioaccumulation kinetics (rates of uptake and elimination) of sediment-associated Cr-51, Ni-63 and organic-associated C- 14 in three common benthic invertebrates from the Baltic Sea (the bivalve Macoma balthica, the amphipod Monoporeia affinis and the priapulid worm Halicryptus spinulosus). There were differences between animals and radionuclides in both the rate of uptake and elimination and the maximum amount accumulated. Understanding how and to what degree different deposit-feeding benthic invertebrates are exposed to and bio-accumulate sediment-associated metals are important for both ecological risk assessment and management decisions in coastal ecosystems. (author)

  4. Human exploitation and benthic community structure on a tropical intertidal mudflat

    NARCIS (Netherlands)

    Boer, de W.F.; Prins, H.H.T.

    2002-01-01

    Human exploitation of intertidal marine invertebrates is known to alter benthic community structure. This study describes the impact that harvesting by women and children has on the intertidal community structure of the mudflats of the Saco on Inhaca Island, Mozambique, by comparing the benthic comm

  5. Human exploitation and benthic community structure on a tropical intertidal flat

    NARCIS (Netherlands)

    de Boer, WF; Prins, HHT

    2002-01-01

    Human exploitation of intertidal marine invertebrates is known to alter benthic community structure. This study describes the impact that harvesting by women and children has on the intertidal community structure of the mudflats of the Saco on Inhaca Island, Mozambique, by comparing the benthic comm

  6. Time is no healer: increasing restoration age does not lead to improved benthic invertebrate communities in restored river reaches.

    Science.gov (United States)

    Leps, Moritz; Sundermann, Andrea; Tonkin, Jonathan D; Lorenz, Armin W; Haase, Peter

    2016-07-01

    Evidence for successful restoration of riverine communities is scarce, particularly for benthic invertebrates. Among the multitude of reasons discussed so far for the lack of observed effects is too short of a time span between implementation and monitoring. Yet, studies that explicitly focus on the importance of restoration age are rare. We present a comprehensive study based on 44 river restoration projects in Germany, focusing on standardized benthic invertebrate sampling. A broad gradient ranging from 1 to 25years in restoration age was available. In contrast to clear improvements in habitat heterogeneity, benthic community responses to restoration were inconsistent when compared to control sections. Taxon richness increased in response to restoration, but abundance, diversity and various assessment metrics did not respond clearly. Restoration age was a poor predictor of community composition and community change, as no significant linear responses could be detected using 34 metrics. Moreover, only 5 out of 34 tested metrics showed non-linear shifts at restoration ages of 2 to 3years. This might be interpreted as an indication of a post-restoration disturbance followed by a re-establishment of pre-restoration conditions. BIO-ENV analysis and fourth-corner modeling underlined the low importance of restoration age, but revealed high importance of catchment-scale characteristics (e.g., ecoregion, catchment size and land use) in controlling community composition and community change. Overall, a lack of time for community development did not appear to be the ultimate reason for impaired benthic invertebrate communities. Instead, catchment-scale characteristics override the effectiveness of restoration. To enhance the ecological success of future river restoration projects, we recommend improving water quality conditions and catchment-scale processes (e.g., connectivity and hydrodynamics) in addition to restoring local habitat structure. PMID:27046138

  7. A Study of the Impact of a Pipeline Construction on Estuarine Benthic Invertebrate Communities

    Science.gov (United States)

    Lewis, L. J.; Davenport, J.; Kelly, T. C.

    2002-08-01

    The effects of a pipeline construction on benthic invertebrates were investigated using a Before/After impact protocol at Clonakilty Bay, West Cork, Ireland. Benthic invertebrates were sampled once before the excavation and at one, two, three and six months after the completion of the work. Analysis was designed to compare natural variation over time within control sites with the variation that occurred in the disturbed site from before to after construction. Invertebrate samples were dominated by Hediste diversicolor, Scrobicularia plana and Tubifex spp. An impact was obvious in the construction site in that no live invertebrates were found at one month after disturbance, but there followed a gradual recolonization by Hediste diversicolor. Scrobicularia plana failed to recolonize the impacted area during the study. At six months after the disturbance there was no significant difference in the mean number of total individuals (of all species) per core sample amongst all study sites, but the apparent ' recovery ' in the impacted area was due to two taxa only, namely Hediste diversicolor and Tubifex spp. The process of recovery of the benthic community within the impacted area is thus dependent on the species within the surrounding area. Their respective life cycle characteristics and mobilities will have been major factors in determining recovery.

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

    Science.gov (United States)

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

  9. A study on the biodiversity of benthic invertebrates in the waters of Seogwipo, Jeju Island, Korea

    Directory of Open Access Journals (Sweden)

    In-Young Cho

    2014-03-01

    Full Text Available The biodiversity of benthic invertebrates in the intertidal and subtidal regions of Gapado, Beomseom, and Munseom islets was surveyed twice in May and September 2013 to study the state of biodiversity in Seogwipo, Jeju Island. As a result, a total of 77 species, 46 families, 25 orders, 14 classes, and nine phyla of benthic invertebrates were found. The species which were found, by taxon, consisted of the following: 26 species of Cnidaria (34%, 24 species of Mollusca (31%, seven species of Chordata (9%, six species of Arthropoda (8%, six species of Porifera (8%, five species of Echinodermata (7%, one species of Bryozoa (1%, one species of Annelida (1%, and one species of Ctenophora (1%.

  10. Catalog of the benthic invertebrate collections of the Scripps Institution of Oceanography. Porifera

    OpenAIRE

    Luke, Spencer R.

    1998-01-01

    This is the sixth in a series of catalogs of holdings of the Benthic Invertebrate Collections of the Scripps Institution of Oceanography. ... The present catalog, containing 1,162 entries, covers the marine Porifera. The arrangement is systematic and each entry includes a catalog number and relevant field data.... Higher taxonomic categories used are as in J.N.A. Hooper and F. Wiedenmayer (1994, Zoological Catalogue of Australia, Vol. 12, "Porifera", Australian Biological Resources Study. CSI...

  11. Shedding light on detritus: Interactions between invertebrates, bacteria and substrates in benthic habitats

    OpenAIRE

    Admiraal, W.; Breure, A.M.; Kraak, M.H.S.; De Mulder, C.; Hunting, E.R.

    2013-01-01

    The processing of dead organic matter, also known as detritus, is a central ecosystem process driven by detritus feeding organisms that are mostly located at the bottom of water bodies where dead organic matter (OM) accumulates. Detritivorous organisms form communities composed of invertebrates, fungi and bacteria that interact with each other and their substrate. Although it is likely that links between benthic biodiversity and OM processing are driven by similar mechanisms across different ...

  12. Cyanobacteria-derived nitrogen uptake by benthic invertebrates in Lake Taihu: a mesocosm study using 15N labeling

    Directory of Open Access Journals (Sweden)

    Yu J.

    2014-01-01

    Full Text Available Eutrophication of lakes can lead to dominance by cyanobacteria, which are hardly used by zooplankton due to their low nutrition value. However, sedimented cyanobacterial detritus may be a useful source for benthic invertebrates. We studied the Microcystis-derived nitrogen incorporation in benthic invertebrates in Lake Taihu using stable isotopic nitrogen (15N as a tracer. The δ15N of all organisms increased significantly with time after addition of the labeled Microcystis detritus. δ15N values of POM and periphyton peaked earlier than for benthic invertebrates, and the maximum levels were also higher than bivalves, snails and worms (Limnodrilus spp.. Among benthic invertebrates, Radix swinhoei peaked later than other invertebrates, but the maximum level and the excess 15N of the last sampling day were higher. At the end of the experiment, approximately 70% of the added 15N was retained in the benthic food web, while only a small fraction (less than 1% of the added detritus 15N occurred in the pelagic food web. Our results suggest that nitrogen from cyanobacteria can be incorporated more in benthic than pelagic food webs and cyanobacterial blooms may contribute to the development of benthic animals.

  13. Estrutura da comunidade de invertebrados bentônicos em dois cursos d'água do Rio Grande do Sul, Brasil Community structure of benthic invertebrates in two watercourses in Rio Grande do Sul State, southern Brazil

    Directory of Open Access Journals (Sweden)

    Alessandra A. P. Bueno

    2003-03-01

    Full Text Available The benthic fauna has an important role in the trophic chain of limnic environments, serving as food for fishes and crustaceans. This work aimed to identify and compare, quantitative and qualitatively, the macrobenthic communities from two watercourses in Rio Grande do Sul State. Samplings were done with a Surber sampler, monthly, from September 1999 to August 2000, in one of the creeks forming Tainhas River(29º15'30,2"S, 50º13'12,5"W, around São Francisco de Paula city and in Mineiro Creek (29º30'0,2"S, 50º46'50"W, around Taquara city. At each sampling point, physical and chemical variables of the waters were registered. In the laboratory, the samples were sorted out and the animals identified and quantified. Dissolved oxigen, pH and stream speed were very similar for both environments, whilst conductivity had extreme values. Insects, crustaceans, acari and molluscs dominated in the samples. Abundance, richness and diversity indexes in Tainhas subsidiary had relatively higher average values than Mineiro Creek. Similarity matrix groupings between sampling units indicate three groups. Our research revealed important characteristics of the ecology and distribution of benthic invertebrates, information that can subsidise future environmental monitoring in the region of São Francisco de Paula and Taquara.

  14. Maximum ecological potential of tropical reservoirs and benthic invertebrate communities.

    Science.gov (United States)

    Molozzi, Joseline; Feio, Maria João; Salas, Fuensanta; Marques, João Carlos; Callisto, Marcos

    2013-08-01

    The Reference Condition Approach (RCA) is now widely adopted as a basis for the evaluation of the ecological quality of water bodies. In accordance with the RCA, the integrity of communities found in a given location should be analyzed according to their deviation from the communities that would be expected in the absence of anthropogenic disturbances. The RCA was used here with the aim of defining the Maximum Ecological Potential (MEP) of tropical reservoirs located in the hydrographical basin of the Paraopeba River in the state of Minas Gerais, Brazil. Among the reservoirs, Serra Azul is used as a water supply and is located in a core area of environmental protection where tourism is not allowed and the native vegetation is conserved. The benthic macroinvertebrate communities at 90 sites located in three reservoirs were analyzed and sampled every 3 months over 2 years. The temporal patterns of the communities in the three reservoirs were analyzed (2nd-STAGE MDS and ANOSIM) and were not significantly related to seasonal fluctuations in temperature and precipitation. Twenty-eight sites belonging to the Serra Azul reservoir were selected to define the MEP of these reservoirs because these sites had the lowest human disturbance levels. The macroinvertebrate taxa present in the selected MEP sites are similar to those of natural lakes and different from the communities of disturbed sites. The biological classification of these sites revealed two groups with distinct macroinvertebrate communities. This distinction was related to climatic variables, bottom substrate type, the presence of gravel/boulders, coarse sand, silt, clay or muck, depth, and the shoreline substrate zone. These two subsets of biological communities and respective environmental conditions can serve as a basis for the future implementation of ecological quality monitoring programs for tropical reservoirs in the study area. This approach can also, however, be implemented in other geographic areas

  15. Metamorphosis of Benthic Invertebrate Larvae: A Sensitive Indicator for Detection of Changes in Marine Environmental Quality

    Directory of Open Access Journals (Sweden)

    Xuelei Zhang

    2002-01-01

    Full Text Available Many marine coastal ecosystems are threatened by increasing waste discharge, and bioassays are needed because chemical and physical tests alone are not sufficient to assess potential effects on aquatic biota. In light of the fact that larval metamorphosis of benthic invertebrates is usually very sensitive to environmental changes, this paper reviews sensitivity comparisons of larval metamorphosis with other common bioassays in different species and those in different developmental stages of the same species, and it discusses the potential use of larval metamorphosis as an indicator of marine environmental quality.

  16. The Distribution, Abundance and Seasonality of Benthic Macro Invertebrate in Okpoka Creek Sediments, Niger Delta, Nigeria

    OpenAIRE

    J.F.N. Abowei

    2010-01-01

    The distribution, abundance and seasonality of benthic macro invertebrates in Okpoka creeksediments were studied for a period of one year (January-December 2006). Polychaeta was highest andconstituted 82.8%. The others were Bivalvia (4.6%), Crustacea (4.5%) and Oligochaeta (3.9%), Gastropoda(2.1%) and Insecta (2.0%). From nineteen (19) species encountered in the area, all the species of the class(Polychaeta) with the exception of Nereis virens occurred in all the stations. The species found w...

  17. Benthic invertebrate fauna in the islets of Namuseom and Bukhyeongjeseom off Busan

    Directory of Open Access Journals (Sweden)

    Hosung Hwang

    2014-06-01

    Full Text Available This study was conducted to examine the benthic invertebrate fauna inhabiting in the subtidal zone in and around the islets of Namuseom and Bukhyeongjeseom off the coast of Busan by SCUBA diving in September 2013. As a consequence, it was confirmed that a total of 6 phyla, 14 classes, 20 orders, 46 families, and 73 species of zoobenthos inhabit in and around those islets. The total number of species surveyed by taxon during the study is 22 species of Arthropoda (30%, 20 species of Mollusca (27%, 15 species of Cnidaria (21%, 10 species of Echinodermata (14%, four species of Poridera (5%, and two species of Chordata.

  18. Benthic invertebrate fauna in the islets of Namuseom and Bukhyeongjeseom off Busan

    OpenAIRE

    Hosung Hwang; Jisoon Kang; In-Young Cho; Dong-Won Kang; Woon Kee Paek; Seok Hyun Lee

    2014-01-01

    This study was conducted to examine the benthic invertebrate fauna inhabiting in the subtidal zone in and around the islets of Namuseom and Bukhyeongjeseom off the coast of Busan by SCUBA diving in September 2013. As a consequence, it was confirmed that a total of 6 phyla, 14 classes, 20 orders, 46 families, and 73 species of zoobenthos inhabit in and around those islets. The total number of species surveyed by taxon during the study is 22 species of Arthropoda (30%), 20 species of Mollusca (...

  19. Distribution of benthic marine invertebrates at northern latitudes ― An evaluation applying multi-algorithm species distribution models

    Science.gov (United States)

    Meißner, Karin; Fiorentino, Dario; Schnurr, Sarah; Martinez Arbizu, Pedro; Huettmann, Falk; Holst, Sabine; Brix, Saskia; Svavarsson, Jörundur

    2014-01-01

    Different techniques of species distribution modeling were applied to evaluate the distribution of eight benthic marine species in Icelandic waters. The species examined were Symplectoscyphus tricuspidatus, Stegopoma plicatile (both Hydrozoa), Prionospio cirrifera, Amphicteis gunneri (both Polychaeta), Desmosoma strombergi, Eurycope producta (both Isopoda), Andaniella pectinata and Harpinia crenulata (both Amphipoda). Information on 13 environmental variables (temperature mean, temperature mean SD, temperature minimum, temperature maximum, salinity mean, salinity mean SD, oxygen content, particulate organic carbon, seasonal variation index, bottom roughness, sediment thickness, acidification) and records of occurrences of these eight species was collated in an ArcGIS project. Modeling methods applied were MARS, TreeNet, and MaxENT. According to area under the receiver operating curve (AUC) model assessment values, models with moderate to outstanding discriminatory power were found for all species. There was a good overlap in the overall pattern of prediction for most species independent on the modeling technique. Among the three applied techniques MARS seemed to generalize most whereas TreeNet predictions very precisely reflected information from the training data set. The distribution of the selected benthic invertebrate species in Icelandic waters could be linked to a variety of environmental factors related to oceanography, seabed topography and human impact. Their multivariate interactions acted as a structuring force of species distribution, instead of just their one by one individual influence. The selected predictors varied between the different models for the same species. They substituted each other in different models. The expected distribution of the examined species was mapped for a seascape of known environmental settings. Such maps will serve as excellent references in future impact studies and enable the detection of changes in the distribution of

  20. A comparative analysis of restoration measures and their effects on hydromorphology and benthic invertebrates in 26 central and southern European rivers.

    NARCIS (Netherlands)

    Jähnig, S.C.; Brabec, K.; Buffagni, A.; Erba, S.; Lorenz, A.; Ofenböck, T.; Verdonschot, P.F.M.; Hering, D.

    2010-01-01

    1. Hydromorphological river restoration usually leads to habitat diversification, but the effects on benthic invertebrates, which are frequently used to assess river ecological status, are minor. We compared the effects of river restoration on morphology and benthic invertebrates by investigating 26

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

    International Nuclear Information System (INIS)

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

  2. Waves affect predator-prey interactions between fish and benthic invertebrates.

    Science.gov (United States)

    Gabel, Friederike; Stoll, Stefan; Fischer, Philipp; Pusch, Martin T; Garcia, Xavier-François

    2011-01-01

    Little is known about the effects of waves on predator-prey interactions in the littoral zones of freshwaters. We conducted a set of mesocosm experiments to study the differential effects of ship- and wind-induced waves on the foraging success of littoral fish on benthic invertebrates. Experiments were conducted in a wave tank with amphipods (Gammarus roeseli) as prey, and age-0 bream (Abramis brama, B0), age-0 and age-1 dace (Leuciscus leuciscus, D0 and D1) as predators. The number of gammarids suspended in the water column was higher in the wave treatments compared to a no-wave control treatment, especially during pulse waves mimicking ship-induced waves in comparison to continuous waves mimicking wind-induced waves. The resulting higher prey accessibility in the water column was differently exploited by the three types of predatory fish. D0 and D1 showed significantly higher foraging success in the pulse wave treatment than in the continuous and control treatments. The foraging success of D0 appears to be achieved more easily, since significantly higher swimming activity and more foraging attempts were recorded only for D1 under the wave treatments. In contrast, B0 consumed significantly fewer gammarids in both wave treatments than in the control. Hence, waves influenced predator-prey interactions differently depending on wave type and fish type. It is expected that regular exposure to ship-induced waves can alter littoral invertebrate and fish assemblages by increasing the predation risk for benthic invertebrates that are suspended in the water column, and by shifting fish community compositions towards species that benefit from waves. PMID:21104276

  3. Field data reveal low critical chemical concentrations for river benthic invertebrates.

    Science.gov (United States)

    Berger, Elisabeth; Haase, Peter; Oetken, Matthias; Sundermann, Andrea

    2016-02-15

    River ecosystems are of immense ecological and social importance. Despite the introduction of wastewater treatment plants and advanced chemical authorization procedures in Europe, chemical pollution is still a major threat to freshwater ecosystems. Here, large-scale monitoring data was exploited to identify taxon-specific chemical concentrations beyond which benthic invertebrate taxa are unlikely to occur using Threshold Indicator Taxa Analysis (TITAN). 365 invertebrate taxa and 25 organic chemicals including pesticides, pharmaceuticals, plasticisers, flame retardants, complexing agents, a surfactant and poly- and monocyclic aromatic hydrocarbons from a total of 399 sites were analysed. The number of taxa that responded to each of these chemicals varied between 0% and 21%. These sensitive taxa belonged predominantly to the groups Plecoptera, Coleoptera, Trichoptera, Ephemeroptera, Turbellaria, Megaloptera, Crustacea, and Diptera. Strong effects were observed in response to wastewater-associated compounds, confirming that wastewater is an important cause of biological degradation. The majority of change points identified for each compound were well below predicted no-effect concentrations derived from laboratory toxicity studies. Thus, the results show that chemicals are likely to induce effects in the environment at concentrations much lower than expected based on laboratory experiments. Overall, it is confirmed that chemical pollution is still an important factor shaping the distribution of invertebrate taxa, suggesting the need for continued efforts to reduce chemical loads in rivers. PMID:26706759

  4. Do acid volatile sulfides (AVS) influence the accumulation of sediment-bound metals to benthic invertebrates under natural field conditions?

    Science.gov (United States)

    De Jonge, Maarten; Dreesen, Freja; De Paepe, Josefina; Blust, Ronny; Bervoets, Lieven

    2009-06-15

    The present study evaluates the influence of acid volatile sulfides (AVS) on accumulation of sediment-bound metals in benthic invertebrates under natural field conditions. Natural sediments, pore water, surface water, and two species of widespread benthic invertebrates (Chironomus gr. thummi and Tubifex tubifex) were collected from 17 historical polluted Flemish lowland rivers and measured for metal concentrations. Different sediment characteristics were determined (AVS, organic matter, clay content) and multiple regression was used to study their relationship with accumulated metals in the invertebrates. Physical and chemical analysis of the field samples indicated low metal concentrations in the water and pore water, but very high metal concentrations in the sediment and the invertebrates, especially for Pb (5.99 micromol/ g). In general, metal accumulation in chironomids and tubificid worms was most strongly correlated with total metal concentrations in the sediment and sediment metal concentrations normalized for organic matter and clay content. Following the results of the linear regression model, AVS did not turn out to be a significant variable in describing variation in metal accumulation. Our study clearly demonstrates that, in addition to the results gained from experiments under lab conditions, benthic invertebrates can accumulate metals from unspiked field sediments even when there's an excess of AVS. PMID:19603670

  5. Scale-dependent effects of river habitat quality on benthic invertebrate communities - Implications for stream restoration practice.

    Science.gov (United States)

    Stoll, Stefan; Breyer, Philippa; Tonkin, Jonathan D; Früh, Denise; Haase, Peter

    2016-05-15

    Although most stream restoration projects succeed in improving hydromorphological habitat quality, the ecological quality of the stream communities often remains unaffected. We hypothesize that this is because stream communities are largely determined by environmental properties at a larger-than-local spatial scale. Using benthic invertebrate community data as well as hydromorphological habitat quality data from 1087 stream sites, we investigated the role of local- (i.e. 100m reach) and regional-scale (i.e. 5km ring centered on each reach) stream hydromorphological habitat quality (LQ and RQ, respectively) on benthic invertebrate communities. The analyses showed that RQ had a greater individual effect on communities than LQ, but the effects of RQ and LQ interacted. Where RQ was either good or poor, communities were exclusively determined by RQ. Only in areas of intermediate RQ, LQ determined communities. Metacommunity analysis helped to explain these findings. Species pools in poor RQ areas were most depauperated, resulting in insufficient propagule pressure for species establishment even at high LQ (e.g. restored) sites. Conversely, higher alpha diversity and an indication of lower beta dispersion signals at mass effects occurring in high RQ areas. That is, abundant neighboring populations may help to maintain populations even at sites with low LQ. The strongest segregation in species co-occurrence was detected at intermediate RQ levels, suggesting that communities are structured to the highest degree by a habitat/environmental gradient. From these results, we conclude that when restoring riverine habitats at the reach scale, restoration projects situated in intermediate RQ settings will likely be the most successful in enhancing the naturalness of local communities. With a careful choice of sites for reach-scale restoration in settings of intermediate RQ and a strategy that aims to expand areas of high RQ, the success of reach-scale restoration in promoting the

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

    Directory of Open Access Journals (Sweden)

    Antony DAVIES

    2001-09-01

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

  7. Eco-environmental impact assessment of pre-leisure beach nourishment on the benthic invertebrate community at Anping coast

    Science.gov (United States)

    Shih, Chun-Han; Kuo, Yi-Yu; Chu, Ta-Jen; Chou, Wen-Chieh; Chang, Wei-Tse; Lee, Ying-Chou

    2011-06-01

    In recent years, owing to global warming and the rising sea levels, beach nourishment and groin building have been increasingly employed to protect coastal land from shoreline erosion. These actions may degrade beach habitats and reduce biomass and invertebrate density at sites where they were employed. We conducted an eco-environmental evaluation at the Anping artificial beach-nourishment project area. At this site, sand piles within a semi-enclosed spur groin have been enforced by use of eco-engineering concepts since 2003. Four sampling sites were monitored during the study period from July 2002 to September 2008. The environmental impact assessment and biological investigations that we conducted are presented here. The results from this study indicate that both biotic (number of species, number of individual organisms, and Shannon-Wiener diversity) and abiotic parameters (suspended solids, biological oxygen demand, chemical oxygen demand, dissolved inorganic nitrogen, dissolved inorganic phosphorus, total phosphorus, total organic carbon, median diameter, and water content) showed significant differences before and after beach engineering construction. Biological conditions became worse in the beginning stages of the engineering but improved after the restoration work completion. This study reveals that the composition of benthic invertebrates changed over the study period, and two groups of organisms, Bivalvia and Gastropoda, seemed to be particularly suitable to this habitat after the semi-enclosed artificial structures completion.

  8. Eco-Environmental Impact Assessment of Pre-Leisure Beach Nourishment on the Benthic Invertebrate Community at Anping Coast

    Institute of Scientific and Technical Information of China (English)

    Chun-Han SHIH; Yi-Yu KUO; Ta-Jen CHU; Wen-Chieh CHOU; Wei-Tse CHANG; Ying-Chou LEE

    2011-01-01

    In recent years, owing to global warming and the rising sea levels, beach nourishment and groin building have been increasingly employed to protect coastal land from shoreline erosion. These actions may degrade beach habitats and reduce biomass and invertebrate density at sites where they were employed. We conducted an eco-environmental evaluation at the Anping artificial beach-nourishment project area. At this site, sand piles within a semi-enclosed spur groin have been enforced by use of eco-engineering concepts since 2003. Four sampling sites were monitored during the study period from July 2002 to September 2008. The environmental impact assessment and biological investigations that we conducted are presented here. The results from this study indicate that both biotic (number of species, number of individual organisms, and Shannon-Wiener diversity) and abiotic parameters (suspended solids, biological oxygen demand, chemical oxygen demand, dissolved inorganic nitrogen, dissolved inorganic phosphorus, total phosphorus, total organic carbon, median diameter, and water content) showed significant differences before and after beach engineering construction. Biological conditions became worse in the beginning stages of the engineering but improved after the restoration work completion.This study reveals that the composition of benthic invertebrates changed over the study period, and two groups oforganisms, Bivalvia and Gastropoda, seemed to be particularly suitable to this habitat after the semi-enclosed artificial structures completion.

  9. Uptake and speciation of vanadium in the benthic invertebrate Hyalella azteca.

    Science.gov (United States)

    Jensen-Fontaine, Madeleine; Norwood, Warren P; Brown, Mitra; Dixon, D George; Le, X Chris

    2014-01-01

    Vanadium has the potential to leach into the environment from petroleum coke, an oil sands byproduct. To determine uptake of vanadium species in the biota, we exposed the benthic invertebrate Hyalella azteca with increasing concentrations of two different vanadium species, V(IV) and V(V), for seven days. The concentrations of vanadium in the H. azteca tissue increased with the concentration of vanadium in the exposure water. Speciation analysis revealed that V(IV) in the exposure water was oxidized to V(V) between renewal periods, and therefore the animals were mostly exposed to V(V). Speciation analysis of the H. azteca tissue showed the presence of V(V), V(IV), and an unidentified vanadium species. These results indicate the uptake and metabolism of vanadium by H. azteca. Because H. azteca are widely distributed in freshwater systems and are an important food supply for many fish, determining the uptake and metabolism of vanadium allows for a better understanding of the potential environmental effects on invertebrates. PMID:24295153

  10. Modeling of Bioaccumulation in Marine Benthic Invertebrates Using a Multispecies Experimental Approach.

    Science.gov (United States)

    Diepens, Noël J; Van den Heuvel-Greve, Martine J; Koelmans, Albert A

    2015-11-17

    The causal links between species traits and bioaccumulation by marine invertebrates are poorly understood. We assessed these links by measuring and modeling polychlorinated biphenyl bioaccumulation by four marine benthic species. Uniformity of exposure was achieved by testing each species in the same aquarium, separated by enclosures, to ensure that the observed variability in bioaccumulation was due to species traits. The relative importance of chemical uptake from pore water or food (organic matter, OM) ingestion was manipulated by using artificial sediment with different OM contents. Biota sediment accumulation factors (BSAFs) ranged from 5 to 318, in the order Nereis virens < Arenicola marina ≈ Macoma balthica < Corophium volutator. Calibration of a kinetic model provided species-specific parameters that represented the key species traits, thus illustrating how models provide an opportunity to read across benthic species with different feeding strategies. Key traits included species-specific differentiation between (1) ingestion rates, (2) ingestion of suspended and settled OM, and (3) elimination rates. The high BSAF values and their concomitant variability across the species challenges approaches for exposure assessment based on pore water concentration analysis and equilibrium partition theory. We propose that combining multienclosure testing and modeling will substantially improve exposure assessment in sediment toxicity tests. PMID:26465976

  11. Length-weight relationships of 216 North Sea benthic invertebrates and fish

    NARCIS (Netherlands)

    Robinson, L.; Greenstreet, S.P.R.; Reiss, H.; Callaway, R.; Craeymeersch, J.A.M.; Boois, de I.J.

    2010-01-01

    Size-based analyses of marine animals are increasingly used to improve understanding of community structure and function. However, the resources required to record individual body weights for benthic animals, where the number of individuals can reach several thousand in a square metre, are often pro

  12. 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

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

    DEFF Research Database (Denmark)

    Josefson, Alf B.; Göke, Cordula

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

  14. 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.

  15. INFLUENCE OF SOOT CARBON ON THE BIOACCULUMATION OF SEDIMENT-BOUND POLYCYCLIC AROMATIC HYDROCARBONS BY MARINE BENTHIC INVERTEBRATES: AN INTERSPECIES COMPARISON

    Science.gov (United States)

    The sorption of polycyclic aromatic hydrocarbons (PAHs) to soot carbon in marine sediments has been hypothesized to reduce PAH bioavailability. This hypothesis was tested for eight species of marine benthic invertebrates (four polychaete worms, Clymenella torquata, Nereis virens,...

  16. Temporal abiotic variability structures invertebrate communities in agricultural drainage ditches

    NARCIS (Netherlands)

    M.H. Whatley; J.A. Vonk; H.G. van der Geest; W. Admiraal

    2015-01-01

    Abiotic variability is known to structure lotic invertebrate communities, yet its influence on lentic invertebrates is not clear. This study tests the hypothesis that variability of nutrients and macro-ions are structuring invertebrate communities in agricultural drainage ditches. This was determine

  17. 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

  18. Carbon and nitrogen stable isotope ratios of subtidal benthic invertebrates in an estuarine mangrove ecosystem (Andhra Pradesh, India)

    OpenAIRE

    Bouillon, Steven; Raman, AV; Dauby, P; F. Dehairs

    2002-01-01

    In order to assess the relative trophic importance of mangrove litterfall and aquatic primary production in the mangrove creeks of the Coringa Wildlife Sanctuary (Andhra Pradesh, India) and the adjacent semi-enclosed Kakinada Bay, carbon and nitrogen stable isotope ratios were determined in a variety of benthic invertebrate species collected at 22 sites during the pre-monsoon period (May-June) of 1997 and 1999. delta(13)C values showed little interspecific variation at any given location, but...

  19. Research on the relationship between benthic invertebrates and aquatic ecosystem health of SUDS%SUDS水健康与底栖无脊椎动物的关系研究

    Institute of Scientific and Technical Information of China (English)

    严明渝; 刘惠清; 王灵芝

    2012-01-01

    The temporal and spatial features of physio-chemical indies and the structure of benthic invertebrates of 4 SUDS ponds within Dunfermline were analyzed, which provided suggestions for the SUDS design and construction of China. Results showed that diversity and the ratio of sensitive of benthic invertebrates were Wetland>Pond 3>Pond 2>Pond 1. The structure of benthic invertebrates was significantly negative correlated with total organic nitrogen and conductivity. Moreover, benthic invertebrates were significantly correlated with environmental factors. The depth, nutrient input and pervious patch ratio of SUDS had great influences on the structure of benthic invertebrates. In wetland, exotic species would gradually replace native species.%对苏格兰邓佛姆林郡4个城市可持续排水系统(sustainable urban drainage system,SUDS)的理化指标及底栖无脊椎动物群落结构的时空变化特征进行了分析.结果表明:底栖无脊椎动物的丰富度及敏感种比重为人工湿地>3号滞留池>2号滞留池>1号滞留池,底栖无脊椎动物的丰富度与敏感种比重与环境要素显著相关,SUDS的深度、流域内透水斑块比重和污染物输入量对底栖动物群落结构及污染物的移除率有显著影响,随时间的延长,外来种逐渐替代了人工湿地的本地种.

  20. Diversity and community structure of epibenthic invertebrates and fish in the North Sea

    DEFF Research Database (Denmark)

    Callaway, R.; Alsväg, J.; de Boois, I.;

    2002-01-01

    The structure of North Sea benthic invertebrate and fish communities is an important indicator of anthropogenic and environmental impacts. Although North Sea fish stocks are monitored regularly, benthic fauna are not. Here, we report the results of a survey carried out in 2000, in which five...... nations sampled the epibenthic and fish fauna at 270 stations throughout the North Sea. The aim of the survey was to investigate the diversity and community structure of epibenthic and fish communities and to identify relationships with environmental factors, including the frequency of commercial otter...... and beam trawling disturbance. Epibenthic species diversity was lower in the southern North Sea than in central and northern areas. Fish, conversely, were more diverse in the south. The 50 m, 100 m and 200 m depth contours broadly defined the boundaries of benthic and fish communities. The abundance...

  1. The effect of manipulations of freshwater sediments on responses of benthic invertebrates in whole-sediment toxicity tests

    Energy Technology Data Exchange (ETDEWEB)

    Day, K.E.; Kirby, R.S.; Reynoldson, T.B. [National Water Research Inst., Burlington, Ontario (Canada). Dept. of the Environment

    1995-08-01

    Manipulations of freshwater sediment were performed to remove indigenous organisms prior to conducting toxicity tests with three species of benthic invertebrates. The effects of these treatments on end points in bioassays were compared within and between two sediments, i.e., a ``clean`` sediment and a ``contaminated`` sediment. In addition, the effects of manipulations on the physicochemical structure of the two sediments and the presence of metals, PAHs, and PCBs in the contaminated sediment were examined. The amphipod Hyalella azteca was most sensitive to the manipulations and had low survival in sediment that was sterilized. Growth (milligrams dry weight per individual) was affected by the presence of contaminants. Survival of Chironomus riparius was not affected by any manipulation but was reduced by contaminants as well as indigenous organisms. Growth of C. riparius was higher in autoclaved sediment but lower in sediment containing endemic tubificid worms. Production of young by Tubifex tubifex increased in sediment that was irradiated, possibly due to increased detrital material. Particle size distribution, metals, nutrients, and PAHs varied little as a function of manipulation; however, sieving of sediment through 250-{micro}m mesh did reduce percent total organic carbon (TOC), percent loss on ignition (LOI), and concentrations of some PCBs in either clean or contaminated sediment. Manipulation of sediments to remove endemic species should be determined on a case-by-case basis and is specific to the organisms used in toxicity tests.

  2. Response of rocky invertebrate diversity, structure and function to the vertical layering of vegetation

    Science.gov (United States)

    Bustamante, María; Tajadura, Javier; Gorostiaga, José María; Saiz-Salinas, José Ignacio

    2014-06-01

    Macroalgae comprise a prominent part of the rocky benthos where many invertebrates develop, and are believed to be undergoing severe declines worldwide. In order to investigate how the vegetation structure (crustose, basal and canopy layers) contributes to the diversity, structure and function of benthic invertebrates, a total of 31 subtidal transects were sampled along the northeast Atlantic coast of Spain. Significant positive relationships were found between the canopy layer and faunal abundance, taxonomic diversity and functional group diversity. Canopy forming algae were also related to epiphytic invertebrates, medium size forms, colonial strategy and suspensivores. By contrast, basal algae showed negative relationships with all variables tested except for detritivores. Multivariate multiple regression analyses (DISTLM) point to crustose as well as canopy layers as the best link between seaweeds and invertebrate assemblage structure. A close relationship was found between taxonomic and functional diversities. In general, low levels of taxonomic redundancy were detected for functional groups correlated with vegetation structure. A conceptual model based on the results is proposed, describing distinct stages of invertebrate assemblages in relation to the vertical structure of vegetation.

  3. Metals-contaminated benthic invertebrates in the Clark Fork River, Montana: Effects on age-0 brown trout and rainbow trout

    Science.gov (United States)

    Woodward, Daniel F.; Farag, Aïda M.; Bergman, Harold L.; Delonay, Aaron J.; Little, Edward E.; Smiths, Charlie E.; Barrows, Frederic T.

    1995-01-01

    Benthic organisms in the upper Clark Fork River have recently been implicated as a dietary source of metals that may be a chronic problem for young-of-the-year rainbow trout (Oncorhynchus mykiss). In this present study, early life stage brown trout (Salmo trutta) and rainbow trout were exposed for 88 d to simulated Clark Fork River water and a diet of benthic invertebrates collected from the river. These exposures resulted in reduced growth and elevated levels of metals in the whole body of both species. Concentrations of As, Cd, Cu, and Pb increased in whole brown trout; in rainbow trout, As and Cd increased in whole fish, and As also increased in liver. Brown trout on the metals-contaminated diets exhibited constipation, gut impaction, increased cell membrane damage (lipid peroxidation), decreased digestive enzyme production (zymogen), and a sloughing of intestinal mucosal epithelial cells. Rainbow trout fed the contaminated diets exhibited constipation and reduced feeding activity. We believe that the reduced standing crop of trout in the Clark Fork River results partly from chronic effects of metals contamination in benthic invertebrates that are important as food for young-of-the-year fish.

  4. Genetic structuring across marine biogeographic boundaries in rocky shore invertebrates.

    Directory of Open Access Journals (Sweden)

    Adriana Villamor

    Full Text Available Biogeography investigates spatial patterns of species distribution. Discontinuities in species distribution are identified as boundaries between biogeographic areas. Do these boundaries affect genetic connectivity? To address this question, a multifactorial hierarchical sampling design, across three of the major marine biogeographic boundaries in the central Mediterranean Sea (Ligurian-Tyrrhenian, Tyrrhenian-Ionian and Ionian-Adriatic was carried out. Mitochondrial COI sequence polymorphism of seven species of Mediterranean benthic invertebrates was analysed. Two species showed significant genetic structure across the Tyrrhenian-Ionian boundary, as well as two other species across the Ionian Sea, a previously unknown phylogeographic barrier. The hypothesized barrier in the Ligurian-Tyrrhenian cannot be detected in the genetic structure of the investigated species. Connectivity patterns across species at distances up to 800 km apart confirmed that estimates of pelagic larval dispersal were poor predictors of the genetic structure. The detected genetic discontinuities seem more related to the effect of past historical events, though maintained by present day oceanographic processes. Multivariate statistical tools were used to test the consistency of the patterns across species, providing a conceptual framework for across-species barrier locations and strengths. Additional sequences retrieved from public databases supported our findings. Heterogeneity of phylogeographic patterns shown by the 7 investigated species is relevant to the understanding of the genetic diversity, and carry implications for conservation biology.

  5. Profundal benthic invertebrates in an oligotrophic tropical lake: different strategies for coping with anoxia

    Directory of Open Access Journals (Sweden)

    María del Carmen Hernández

    2014-05-01

    Full Text Available The deep benthic communities of tropical lakes are poorly understood with respect to their composition, abundance, biomass and regulatory factors. Whereas the hypolimnia of temperate oligotrophic lakes remain oxygenated, the higher temperatures in tropical lakes frequently lead to the rapid development of hypolimnetic anoxia independent of trophic status. The deep benthic communities of tropical lakes must therefore develop strategies to respond to anoxic conditions. The dynamics of the deep benthic community of Lake Alchichica were studied over 15 months. We hypothesized that the sedimentation of the winter diatom bloom constitutes an input of high-quality food that contributes to the establishment and development of the deep benthic community. However, the remineralization of this organic matter leads to the prompt development of hypolimnetic anoxia, thus limiting the establishment and/or persistence of the deep benthic community. In contrast with the diverse littoral benthic community (50 taxa in Lake Alchichica, only two species constitute its deep benthic community, the ostracod Candona cf. patzcuaro and the chironomid Chironomus cf. austini, which combined exhibit a low density (1197±1976 ind m-2 and biomass (16.13±30.81 mg C m-2. C. patzcuaro is dominant and is present throughout the year, whereas Ch. austini is recorded only when the bottom water of the lake is oxygenated. A comparison with the analogous but temperate Lake Mergozzo in Italy illustrates the role that anoxia plays in tropical lakes by diminishing not only taxonomic richness (13 versus 2 spp. in temperate versus tropical lakes, respectively but also abundance (1145 versus 287 ind m-2, respectively. C. patzcuaro is found throughout the annual cycle of the lake’s profundal zone, entering into diapause during the anoxic period and recovering as soon as the profundal zone reoxygenates. Ch. austini has adjusted its life cycle to use the habitat and available resources while

  6. Toxicity of nickel-spiked freshwater sediments to benthic invertebrates-Spiking methodology, species sensitivity, and nickel bioavailability

    Science.gov (United States)

    Besser, John M.; Brumbaugh, William G.; Kemble, Nile E.; Ivey, Chris D.; Kunz, James L.; Ingersoll, Christopher G.; Rudel, David

    2011-01-01

    This report summarizes data from studies of the toxicity and bioavailability of nickel in nickel-spiked freshwater sediments. The goal of these studies was to generate toxicity and chemistry data to support development of broadly applicable sediment quality guidelines for nickel. The studies were conducted as three tasks, which are presented here as three chapters: Task 1, Development of methods for preparation and toxicity testing of nickel-spiked freshwater sediments; Task 2, Sensitivity of benthic invertebrates to toxicity of nickel-spiked freshwater sediments; and Task 3, Effect of sediment characteristics on nickel bioavailability. Appendices with additional methodological details and raw chemistry and toxicity data for the three tasks are available online at http://pubs.usgs.gov/sir/2011/5225/downloads/.

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

    DEFF Research Database (Denmark)

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

    2013-01-01

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

  8. Comparative Glycoproteome Analysis: Dynamics of Protein Glycosylation during Metamorphic Transition from Pelagic to Benthic Life Stages in Three Invertebrates

    KAUST Repository

    Chandramouli, Kondethimmanahalli H.

    2012-02-03

    The life cycle of most benthic marine invertebrates has two distinct stages: the pelagic larval stage and the sessile juvenile stage. The transition between the larval stage and the juvenile stage is often abrupt and may be triggered by post-translational modification of proteins. Glycosylation, a very important post-translational modification, influences the biological activity of proteins. We used two-dimensional gel electrophoresis (2-DE) followed by glycoprotein-specific fluorescence staining and mass spectrometry with the goal of identifying glycosylation pattern changes during larval settlement and metamorphosis in barnacles, bryozoans, and polychaetes. Our results revealed substantial changes in the protein glycosylation patterns from larval to juvenile stages. Before metamorphosis, the degree of protein glycosylation was high in the barnacle Balanus (=Amphibalanus) amphitrite and the spionid polychaete Pseudopolydora vexillosa, whereas it increased after metamorphosis in the bryozoan Bugula neritina. We identified 19 abundant and differentially glycosylated proteins in these three species. Among the proteins, cellular stress- and metabolism-related proteins exhibited distinct glycosylation in B. amphitrite and B. neritina, whereas fatty acid metabolism-related proteins were abundantly glycosylated in P. vexillosa. Furthermore, the protein and gene expression analysis of some selected glycoproteins revealed that the degree of protein glycosylation did not always complement with transcriptional and translational changes associated with the larval-juvenile transition. The current study provides preliminary information on protein glycosylation in marine invertebrates that will serve as a solid basis for future comprehensive analysis of glycobiology during larval settlement and metamorphosis. © 2011 American Chemical Society.

  9. Shedding light on detritus: Interactions between invertebrates, bacteria and substrates in benthic habitats

    NARCIS (Netherlands)

    E.R. Hunting

    2013-01-01

    The processing of dead organic matter, also known as detritus, is a central ecosystem process driven by detritus feeding organisms that are mostly located at the bottom of water bodies where dead organic matter (OM) accumulates. Detritivorous organisms form communities composed of invertebrates, fun

  10. Application of Multiple Index Development Approaches to Benthic Invertebrate Data from the Virginian Biogeographic Province, USA

    Science.gov (United States)

    Previous work had indicated that the Virginian Province Index did not perform well in a smaller estuarine complex. While it was hoped that the existing Chesapeake Bay Benthic Index of Biotic Integrity, with its greater number of metrics and habitat separation would be more adapt...

  11. Organic carbon in intertidal mangrove forests: sources and utilization by benthic invertebrates

    OpenAIRE

    BOUILLON, S; N. Koedam; Raman, A. V.; Rao, A.V.V.S.; F. Dehairs

    2001-01-01

    In contrast to the large number of studies on the trophic significance of mangrove primary production to the aquatic foodweb, there have been few attempts to provide an overview of the relative importance of different primary carbon sources to invertebrates in the intertidal mangrove habitats. Mangrove sediments from three different mangrove ecosystems (Coringa Wildlife Sanctuary in the Godavari Delta, Andhra Pradesh, India, and Galle and Pambala, Sri Lanka) were analysed for their organic ca...

  12. Explaining bathymetric diversity patterns in marine benthic invertebrates and demersal fishes: physiological contributions to adaptation of life at depth.

    Science.gov (United States)

    Brown, Alastair; Thatje, Sven

    2014-05-01

    Bathymetric biodiversity patterns of marine benthic invertebrates and demersal fishes have been identified in the extant fauna of the deep continental margins. Depth zonation is widespread and evident through a transition between shelf and slope fauna from the shelf break to 1000 m, and a transition between slope and abyssal fauna from 2000 to 3000 m; these transitions are characterised by high species turnover. A unimodal pattern of diversity with depth peaks between 1000 and 3000 m, despite the relatively low area represented by these depths. Zonation is thought to result from the colonisation of the deep sea by shallow-water organisms following multiple mass extinction events throughout the Phanerozoic. The effects of low temperature and high pressure act across hierarchical levels of biological organisation and appear sufficient to limit the distributions of such shallow-water species. Hydrostatic pressures of bathyal depths have consistently been identified experimentally as the maximum tolerated by shallow-water and upper bathyal benthic invertebrates at in situ temperatures, and adaptation appears required for passage to deeper water in both benthic invertebrates and demersal fishes. Together, this suggests that a hyperbaric and thermal physiological bottleneck at bathyal depths contributes to bathymetric zonation. The peak of the unimodal diversity-depth pattern typically occurs at these depths even though the area represented by these depths is relatively low. Although it is recognised that, over long evolutionary time scales, shallow-water diversity patterns are driven by speciation, little consideration has been given to the potential implications for species distribution patterns with depth. Molecular and morphological evidence indicates that cool bathyal waters are the primary site of adaptive radiation in the deep sea, and we hypothesise that bathymetric variation in speciation rates could drive the unimodal diversity-depth pattern over time. Thermal

  13. Distribution pattern of benthic invertebrates in Danish estuaries: The use of Taylor's power law as a species-specific indicator of dispersion and behavior

    DEFF Research Database (Denmark)

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

    2013-01-01

    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......The lack of a common statistical approach describing the distribution and dispersion pattern of marine benthic animals has often hampered the comparability among studies. The purpose of this study is therefore to apply an alternative approach, Taylor's power law, to data on spatial and temporal...... 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 a...

  14. Radiological impact of TEPCO's Fukushima Dai-ichi Nuclear Power Plant accident on invertebrates in the coastal benthic food web

    International Nuclear Information System (INIS)

    Radioactive cesium (134Cs and 137Cs) concentrations in invertebrates of benthic food web (10 taxonomic classes with 46 identified families) collected from wide areas off Fukushima Prefecture (3–500 m depth) were inspected from July 2011, four months after the Fukushima Dai-ichi Nuclear Power Plant (FDNPP) accident, to August 2013 to elucidate time-series trends among taxa and areas. Cesium-137 was detected in seven classes (77% of 592 specimens). Higher 137Cs concentrations within detected data were often found in areas near or south of the FDNPP, which is consistent with the reported spatial distribution of 137Cs concentrations in highly contaminated seawater and sediments after the FDNPP accident. Overall 137Cs concentrations in invertebrates, the maxima of which (290 Bq kg−1-wet in the sea urchin Glyptocidaris crenularis) were lower than in many demersal fishes, had decreased exponentially with time, and exhibited taxon-specific decreasing trends. Concentrations in Bivalvia and Gastropoda decreased clearly with respective ecological half-lives of 188 d and 102 d. In contrast, decreasing trends in Malacostraca and Polychaeta were more gradual, with longer respective ecological half-lives of 208 d and 487 d. Echinoidea showed no consistent trend, presumably because of effects of contaminated sediments taken into their digestive tract. Comparison of 137Cs concentrations in the invertebrates and those in seawater and sediments suggest that contaminated sediments are the major source of continuing contamination in benthic invertebrates, especially in Malacostraca and Polychaeta. - Highlights: • Radioactive cesium was measured in benthic invertebrates collected off Fukushima. • Results show taxon-specific and area-specific decreases in ecological half-lives. • Reasonable depuration of 137Cs concentration was found in Bivalvia and Gastropoda. • Slow depuration was observed in Polychaeta and Malacostraca. • Sediments are expected to be the major continued

  15. Effect of benthic invertebrates on the desorption of Am-241 and Cm-244 from freshwater sediments

    International Nuclear Information System (INIS)

    Americium and curium are transuranic elements that bind strongly to particulate matter in freshwater environments. This research was conducted to determine if benthic amphipods (Hyalella sp.) or oligochaete worms (Tubifex spp.) alter sediment/water partitioning. Laboratory experiments were conducted in buffered water from Lake Washington (Seattle, WA) with radionuclide tracers added either to the water or to a selected particulate phase - quartz sand, organic detritus, or NBS (National Bureau of Standards) standard river sediment. Samples were collected during a five day exposure period and radioactivity was measured in the water, particulates and organisms. The presence of organisms increased soluble concentrations of Am and Cm. Desorption from particulate phases occurred more readily for Am than for Cm and each isotope was bound most tightly by NBS sediment and least strongly by quartz sand. (author)

  16. Fine-scale distribution and spatial variability of benthic invertebrate larvae in an open coastal embayment in Nova Scotia, Canada.

    Science.gov (United States)

    Daigle, Rémi M; Metaxas, Anna; deYoung, Brad

    2014-01-01

    This study quantified the fine- scale (0.5 km) of variability in the horizontal distributions of benthic invertebrate larvae and related this variability to that in physical and biological variables, such as density, temperature, salinity, fluorescence and current velocity. Larvae were sampled in contiguous 500-m transects along two perpendicular 10-km transects with a 200-µm plankton ring net (0.75-m diameter) in St. George's Bay, Nova Scotia, Canada, in Aug 2009. Temperature, conductivity, pressure and fluorescence were measured with a CTD cast at each station, and currents were measured with an Acoustic Doppler Current Profiler moored at the intersection of the 2 transects. Gastropod, bivalve and, to a lesser extent, bryozoan larvae had very similar spatial distributions, but the distribution of decapod larvae had a different pattern. These findings suggest that taxonomic groups with functionally similar larvae have similar dispersive properties such as distribution and spatial variability, while the opposite is true for groups with functionally dissimilar larvae. The spatial variability in larval distributions was anisotropic and matched the temporal/spatial variability in the current velocity. We postulate that in a system with no strong oceanographic features, the scale of spatially coherent physical forcing (e.g. tidal periodicity) can regulate the formation or maintenance of larval patches; however, swimming ability may modulate it. PMID:25153075

  17. Fine-scale distribution and spatial variability of benthic invertebrate larvae in an open coastal embayment in Nova Scotia, Canada.

    Directory of Open Access Journals (Sweden)

    Rémi M Daigle

    Full Text Available This study quantified the fine- scale (0.5 km of variability in the horizontal distributions of benthic invertebrate larvae and related this variability to that in physical and biological variables, such as density, temperature, salinity, fluorescence and current velocity. Larvae were sampled in contiguous 500-m transects along two perpendicular 10-km transects with a 200-µm plankton ring net (0.75-m diameter in St. George's Bay, Nova Scotia, Canada, in Aug 2009. Temperature, conductivity, pressure and fluorescence were measured with a CTD cast at each station, and currents were measured with an Acoustic Doppler Current Profiler moored at the intersection of the 2 transects. Gastropod, bivalve and, to a lesser extent, bryozoan larvae had very similar spatial distributions, but the distribution of decapod larvae had a different pattern. These findings suggest that taxonomic groups with functionally similar larvae have similar dispersive properties such as distribution and spatial variability, while the opposite is true for groups with functionally dissimilar larvae. The spatial variability in larval distributions was anisotropic and matched the temporal/spatial variability in the current velocity. We postulate that in a system with no strong oceanographic features, the scale of spatially coherent physical forcing (e.g. tidal periodicity can regulate the formation or maintenance of larval patches; however, swimming ability may modulate it.

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

    Directory of Open Access Journals (Sweden)

    Laura MARZIALI

    2011-02-01

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

  19. Synergistic effects of hypoxia and increasing CO2 on benthic invertebrates of the central Chilean coast

    KAUST Repository

    Steckbauer, Alexandra

    2015-07-10

    Ocean acidification (OA) and hypoxic events are an increasing worldwide problem, but the synergetic effects of these factors are seldom explored. However, this synergetic occurrence of stressors is prevalent. The coastline of Chile not only suffers from coastal hypoxia but the cold, oxygen-poor waters in upwelling events are also supersaturated in CO2, a study site to explore the combined effect of OA and hypoxia. We experimentally evaluated the metabolic response of different invertebrate species (2 anthozoans, 9 molluscs, 4 crustaceans, 2 echinoderms) of the coastline of central Chile (33°30′S, 71°37′W) to hypoxia and OA within predicted levels and in a full factorial design. Organisms were exposed to 4 different treatments (ambient, low oxygen, high CO2, and the combination of low oxygen and high CO2) and metabolism was measured after 3 and 6 days. We show that the combination of hypoxia and increased pCO2 reduces the respiration significantly, compared to a single stressor. The evaluation of synergistic pressures, a more realistic scenario than single stressors, is crucial to evaluate the effect of future changes for coastal species and our results provide the first insight on what might happen in the next 100 years.

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

    Science.gov (United States)

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

    2014-12-01

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

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

    Institute of Scientific and Technical Information of China (English)

    王智; 张志勇; 张君倩; 张迎颖; 严少华

    2012-01-01

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

  2. Modelling benthic biophysical drivers of ecosystem structure and biogeochemical response

    Science.gov (United States)

    Stephens, Nicholas; Bruggeman, Jorn; Lessin, Gennadi; Allen, Icarus

    2016-04-01

    The fate of carbon deposited at the sea floor is ultimately decided by biophysical drivers that control the efficiency of remineralisation and timescale of carbon burial in sediments. Specifically, these drivers include bioturbation through ingestion and movement, burrow-flushing and sediment reworking, which enhance vertical particulate transport and solute diffusion. Unfortunately, these processes are rarely satisfactorily resolved in models. To address this, a benthic model that explicitly describes the vertical position of biology (e.g., habitats) and biogeochemical processes is presented that includes biological functionality and biogeochemical response capturing changes in ecosystem structure, benthic-pelagic fluxes and biodiversity on inter-annual timescales. This is demonstrated by the model's ability to reproduce temporal variability in benthic infauna, vertical pore water nutrients and pelagic-benthic solute fluxes compared to in-situ data. A key advance is the replacement of bulk parameterisation of bioturbation by explicit description of the bio-physical processes responsible. This permits direct comparison with observations and determination of key parameters in experiments. Crucially, the model resolves the two-way interaction between sediment biogeochemistry and ecology, allowing exploration of the benthic response to changing environmental conditions, the importance of infaunal functional traits in shaping benthic ecological structure and the feedback the resulting bio-physical processes exert on pore water nutrient profiles. The model is actively being used to understand shelf sea carbon cycling, the response of the benthos to climatic change, food provision and other societal benefits.

  3. Species-area relationships as a tool for the conservation of benthic invertebrates in Italian coastal lagoons

    Science.gov (United States)

    Guilhaumon, François; Basset, Alberto; Barbone, Enrico; Mouillot, David

    2012-12-01

    Over the recent decades, the preservation of coastal and estuarine waters has been recognised as a priority at national and international levels. At the European scale, the Water Framework Directive (WFD) was established with the aim to achieve a good ecological status of all significant water bodies by the year 2015. Among the descriptors used to define the ecological status of water bodies, taxonomic diversity (usually species richness) is a widespread metric employed across taxa and habitats. However, species richness is known to increase with area at a decelerating rate, producing the species-area relationship (SAR). Thus, removing the effect of area (even in case of low magnitude), is mandatory before comparing species richness between sites. Here we tested recently developed multi-model SARs as a standardisation tool for comparing benthic species richness (annelids, arthropods, molluscs and total species richness) in 18 Italian coastal lagoons with a surface area ranging from 0.19 to 552 km2, i.e. three orders of magnitude. However, the sampling effort was often incompletely described and certainly heterogeneous among the studies retrieved from the database. Therefore, we used the number of studies as a proxy for the sampling effort in each lagoon and estimated species richness from observed values using non-parametric occurrence-based estimators. We further corrected for bias that might be induced by sampling efforts being unrepresentative for the surface area of different lagoons. After applying these corrections, we estimated that c. 25-30% of species richness could be explained by surface area. We investigated the spatial congruence of species richness patterns across taxa and showed that molluscs could serve as a potential surrogate for total macro-invertebrate species richness. We further found that the intensity of conservation focus and the gradient of ecological status are decoupled in Italian coastal lagoons. More generally, our study pave the way

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

    Science.gov (United States)

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

    2016-01-01

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

  5. In situ effects of simulated overfishing and eutrophication on settlement of benthic coral reef invertebrates in the Central Red Sea

    OpenAIRE

    Christian Jessen; Voolstra, Christian R.; Christian Wild

    2014-01-01

    In the Central Red Sea, healthy coral reefs meet intense coastal development, but data on the effects of related stressors for reef functioning are lacking. This in situ study therefore investigated the independent and combined effects of simulated 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...

  6. Disjoint geographical distribution of intertidal and nearshore benthic invertebrates in the Southern Hemisphere Distribuciones geográficas disyuntas de invertebrados bentónicos intermareales y del submareal somero en el Hemisferio Sur

    OpenAIRE

    Castilla, Juan C.; RICARDO GUIÑEZ

    2000-01-01

    Biogeographical explanations for the extant and paleo disjoint geographical distribution in the southern hemisphere of five species of nearshore marine benthic invertebrates: Gaimardia trapesina, Ostrea chilensis, Pyura stolonifera taxonomic complex, Aulacomya ater and Concholepas concholepas, showing distinctive reproductive strategies and early life history characteristics are reviewed and analyzed. Through the use of published and new information we contrasted the following hypotheses: a) ...

  7. Distribution pattern of benthic invertebrates in Danish estuaries: The use of Taylor's power law as a species-specific indicator of dispersion and behavior

    Science.gov (United States)

    Kristensen, Erik; Delefosse, Matthieu; Quintana, Cintia O.; Banta, Gary T.; Petersen, Hans Christian; Jørgensen, Bent

    2013-03-01

    The lack of a common statistical approach describing the distribution and dispersion pattern of marine benthic animals has often hampered the comparability among studies. The purpose of this study is therefore to apply an alternative approach, Taylor's power law, to data on spatial and temporal distribution of 9 dominating benthic invertebrate species from two study areas, the estuaries Odense Fjord and Roskilde Fjord, Denmark. The slope (b) obtained from the power relationship of sample variance (s2) versus mean (μ) appears to be species-specific and independent of location and time. It ranges from a low of ~ 1 for large-bodied (> 1 mg AFDW) species (e.g. Marenzelleria viridis, Nereis diversicolor) to a high of 1.6-1.9 for small-bodied (< 1 mg AFDW) species (e.g. Pygospio elegans and Tubificoides benedii). Accordingly, b is apparently a valuable species-specific dispersion index based on biological 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 strong to override environmental influences (e.g. water depth and sediment type). The strong linear relationship between the slope b and intercept log(a) from the power relationship is remarkably similar for all surveys providing a common slope of - 1.63 with the present sampling approach. We suggest that this relationship is an inherent characteristic of Taylor's power law, and that b as a dispersion index may be biased by e.g. sampling errors when this relationship is weak. The correlation strength between b and log(a) could therefore be envisioned as a data quality check.

  8. In situ effects of simulated overfishing and eutrophication on settlement of benthic coral reef invertebrates in the Central Red Sea.

    KAUST Repository

    Jessen, Christian

    2014-04-08

    In the Central Red Sea, healthy coral reefs meet intense coastal development, but data on the effects of related stressors for reef functioning are lacking. This in situ study therefore investigated the independent and combined effects of simulated 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 exclusively colonized shaded tiles. Algae were superior settling competitors on light-exposed tiles. On the shaded tiles, simulated overfishing prevented settlement of hard corals, but significantly increased settlement of polychaetes, while simulated eutrophication only significantly decreased hard coral settlement relative to controls. The combined treatment significantly increased settlement of bryozoans and bivalves compared to controls and individual manipulations, but significantly decreased polychaetes compared to simulated overfishing. These results suggest settlement of polychaetes and hard corals as potential bioindicators for overfishing and eutrophication, respectively, and settlement of bivalves and bryozoans for a combination of both. Therefore, if the investigated stressors are not controlled, phase shifts from dominance by hard corals to that by other invertebrates may occur at shaded reef locations in the Central Red Sea.

  9. In situ effects of simulated overfishing and eutrophication on settlement of benthic coral reef invertebrates in the Central Red Sea

    Directory of Open Access Journals (Sweden)

    Christian Jessen

    2014-04-01

    Full Text Available In the Central Red Sea, healthy coral reefs meet intense coastal development, but data on the effects of related stressors for reef functioning are lacking. This in situ study therefore investigated the independent and combined effects of simulated 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 exclusively colonized shaded tiles. Algae were superior settling competitors on light-exposed tiles. On the shaded tiles, simulated overfishing prevented settlement of hard corals, but significantly increased settlement of polychaetes, while simulated eutrophication only significantly decreased hard coral settlement relative to controls. The combined treatment significantly increased settlement of bryozoans and bivalves compared to controls and individual manipulations, but significantly decreased polychaetes compared to simulated overfishing. These results suggest settlement of polychaetes and hard corals as potential bioindicators for overfishing and eutrophication, respectively, and settlement of bivalves and bryozoans for a combination of both. Therefore, if the investigated stressors are not controlled, phase shifts from dominance by hard corals to that by other invertebrates may occur at shaded reef locations in the Central Red Sea.

  10. Seasonal changes in interstitial salinities and seasonal movements of subtidal benthic invertebrates in the Fraser River estuary, B.C.

    Science.gov (United States)

    Chapman, Peter M.; Brinkhurst, Ralph O.

    1981-01-01

    The subtidal benthic fauna of the lower Fraser River, a salt-wedge estuary, was sampled monthly from June 1977 to August 1978 in mud substrates at six stations ranging from oligohaline to polyhaline. Subtidal interstitial salinities were also measured and were related to the seasonal distribution of the estuarine benthic fauna. Interstitial salinities of silty sediments do not vary diurnally, but the transition zone between salt and fresh interstitial water is cyclically shifted up- and downstream in relation to freshwater discharge, leading to seasonal shifts in the distribution of benthic infaunal species. Seasonal shifts are shown to occur in the oligochaetes Limnodrilus hoffmeisteri, Tubifex tubifex, Tubificoides gabriellae, Paranais litoralis, Specaria fraseri, Nais communis and Nais elinguis, and of the polychaetes Eteone longa, Amphicteis sp. and Polydora kempi japonica. These species comprised over 25% of the total taxa collected and over 60% of the individuals collected. The data on other species distributions do not conflict with the hypothesis of cyclic changes related to seasonal interstitial salinities. The changes vary in extent in relation to runoff, and appear to be a feature of salt-wedge estuaries in general.

  11. CTD, marine invertebrate pathology, benthic organisms, and marine toxic substances and pollutants data collected using CTD casts and other instruments from SEA TRANSPORTER and other platforms in Gulf of Mexico from 20 May 1978 to 15 January 1979 (NODC Accession 8000022)

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — CTD, marine invertebrate pathology, benthic organisms, and marine toxic substances and pollutants data were collected using CTD, net casts, and other instruments...

  12. Lethal and sub-lethal effects of elevated CO2 concentrations on marine benthic invertebrates and fish.

    Science.gov (United States)

    Lee, Changkeun; Hong, Seongjin; Kwon, Bong-Oh; Lee, Jung-Ho; Ryu, Jongseong; Park, Young-Gyu; Kang, Seong-Gil; Khim, Jong Seong

    2016-08-01

    Concern about leakage of carbon dioxide (CO2) from deep-sea storage in geological reservoirs is increasing because of its possible adverse effects on marine organisms locally or at nearby coastal areas both in sediment and water column. In the present study, we examined how elevated CO2 affects various intertidal epibenthic (benthic copepod), intertidal endobenthic (Manila clam and Venus clam), sub-tidal benthic (brittle starfish), and free-living (marine medaka) organisms in areas expected to be impacted by leakage. Acute lethal and sub-lethal effects were detected in the adult stage of all test organisms exposed to varying concentrations of CO2, due to the associated decline in pH (8.3 to 5.2) during 96-h exposure. However, intertidal organisms (such as benthic copepods and clams) showed remarkable resistance to elevated CO2, with the Venus clam being the most tolerant (LpH50 = 5.45). Sub-tidal species (such as brittle starfish [LpH50 = 6.16] and marine medaka [LpH50 = 5.91]) were more sensitive to elevated CO2 compared to intertidal species, possibly because they have fewer defensive capabilities. Of note, the exposure duration might regulate the degree of acute sub-lethal effects, as evidenced by the Venus clam, which showed a time-dependent effect to elevated CO2. Finally, copper was chosen as a model toxic element to find out the synergistic or antagonistic effects between ocean acidification and metal pollution. Combination of CO2 and Cu exposure enhances the adverse effects to organisms, generally supporting a synergistic effect scenario. Overall, the significant variation in the degree to which CO2 adversely affected organisms (viz., working range and strength) was clearly observed, supporting the general concept of species-dependent effects of elevated CO2. PMID:27074931

  13. Invertebrate muscles: thin and thick filament structure; molecular basis of contraction and its regulation, catch and asynchronous muscle

    OpenAIRE

    Hooper, Scott L; Hobbs, Kevin H.; Jeffrey B Thuma

    2008-01-01

    This is the second in a series of canonical reviews on invertebrate muscle. We cover here thin and thick filament structure, the molecular basis of force generation and its regulation, and two special properties of some invertebrate muscle, catch and asynchronous muscle. Invertebrate thin filaments resemble vertebrate thin filaments, although helix structure and tropomyosin arrangement show small differences. Invertebrate thick filaments, alternatively, are very different from vertebrate stri...

  14. Interlinking backscatter, grain size and benthic community structure

    Science.gov (United States)

    McGonigle, Chris; Collier, Jenny S.

    2014-06-01

    The relationship between acoustic backscatter, sediment grain size and benthic community structure is examined using three different quantitative methods, covering image- and angular response-based approaches. Multibeam time-series backscatter (300 kHz) data acquired in 2008 off the coast of East Anglia (UK) are compared with grain size properties, macrofaunal abundance and biomass from 130 Hamon and 16 Clamshell grab samples. Three predictive methods are used: 1) image-based (mean backscatter intensity); 2) angular response-based (predicted mean grain size), and 3) image-based (1st principal component and classification) from Quester Tangent Corporation Multiview software. Relationships between grain size and backscatter are explored using linear regression. Differences in grain size and benthic community structure between acoustically defined groups are examined using ANOVA and PERMANOVA+. Results for the Hamon grab stations indicate significant correlations between measured mean grain size and mean backscatter intensity, angular response predicted mean grain size, and 1st principal component of QTC analysis (all p response predicted mean grain size (r2 = 0.692; p response predicted grain size (p < 0.001), and QTC class (p = 0.009). Mean grain size (Clamshell) shows a significant difference between groups for mean backscatter (p = 0.001); other methods were not significant. PERMANOVA for the Hamon abundance shows benthic community structure was significantly different between acoustic groups for all methods (p ≤ 0.001). Overall these results show considerable promise in that more than 60% of the variance in the mean grain size of the Clamshell grab samples can be explained by mean backscatter or acoustically-predicted grain size. These results show that there is significant predictive capacity for sediment characteristics from multibeam backscatter and that these acoustic classifications can have ecological validity.

  15. Distribution of benthic invertebrates at different depths in a shallow reservoir in the KwaZulu-Natal Midlands

    Directory of Open Access Journals (Sweden)

    M.J. Samways

    1996-02-01

    Full Text Available The bottom of a freshwater reservoir in the KwaZulu-Natal Midlands was sampled for macro-invertebrates and macrophytes at depths of 0.5 m, 1 m, 2 m, and 3 m. The water plants Elodea spp. which did not occur much beyond 1 m appeared to be a major deter-minant for the presence of invertebrates. At 2 m and 3 m, when temperature and light decreased greatly, it was replaced by the algae Chara spp. Over 98 of the macroinvertebrate individuals in 21 species and 14 families occurred in water 1 m or less in depth. At 2 m and deeper, there was a rapid decline of species, with only one, a snail, occurring at 3 m. Odonata species occurred only in water 1 m or less in depth. Among the Ephemeroptera, Caenis sp. was abundant at 0.5 m and the most dominant species of all. At 1 m, the most dominant species was Cleon palidulosum of the Baetidae. Both in terms of food for waterfowl and trout, and as a reserve for aquatic macroin vertebrates, the shallow fringe of the reservoir was playing by far the major role compared with the deeper, open water. It is recommended both for biotic conservation and fishing that reservoirs have a shallow rim and constant water levels.

  16. Relationship between the lability of sediment-bound metals (Cd, Cu, Zn) and their bioaccumulation in benthic invertebrates

    Science.gov (United States)

    Amiard, J.-C.; Geffard, A.; Amiard-Triquet, C.; Crouzet, C.

    2007-04-01

    The present study has investigated metal contamination at nine sites (10 sampling stations) from the English Channel to the Mediterranean Sea, including low level and highly contaminated sediments. Both total and labile concentrations of metals were determined in superficial sediments. The influence of different pHs was tested and metal lability at pHs encountered in the gut of invertebrates (the ragworm Nereis diversicolor, the blue mussel Mytilus edulis, the Japanese oyster Crassostrea gigas) was compared with the distribution of metals in various operationally defined geochemical fractions. Cd showed the highest lability and Cu the lowest, whereas Zn lability was intermediate. Metal concentrations were determined in bivalves at six sites and in worms at three sites. Cd in living organisms and labile Cd in sediments increased in proportion over the gradient of contamination. This relationship did not always hold for Cu and Zn and these exceptions are discussed. Even if sediments are not the only source of metal contamination in marine invertebrates, the procedure proposed here to assess metal bioavailability by remobilising sediment-bound metals at physiological pHs, seems a significant improvement of the existing methodologies of risk assessment.

  17. Can benthic community structure be used to predict the process of bioturbation in real ecosystems?

    Science.gov (United States)

    Queirós, Ana M.; Stephens, Nicholas; Cook, Richard; Ravaglioli, Chiara; Nunes, Joana; Dashfield, Sarah; Harris, Carolyn; Tilstone, Gavin H.; Fishwick, James; Braeckman, Ulrike; Somerfield, Paul J.; Widdicombe, Stephen

    2015-09-01

    Disentangling the roles of environmental change and natural environmental variability on biologically mediated ecosystem processes is paramount to predict future marine ecosystem functioning. Bioturbation, the biogenic mixing of sediments, has a regulating role in marine biogeochemical processes. However, our understanding of bioturbation as a community level process and of its environmental drivers is still limited by loose use of terminology, and a lack of consensus about what bioturbation is. To help resolve these challenges, this empirical study investigated the links between four different attributes of bioturbation (bioturbation depth, activity and distance, and biodiffusive transport); the ability of an index of bioturbation (BPc) to predict each of them; and their relation to seasonality, in a shallow coastal system - the Western Channel Observatory, UK. Bioturbation distance depended on changes in benthic community structure, while the other three attributes were more directly influenced by seasonality in food availability. In parallel, BPc successfully predicted bioturbation distance but not the other attributes of bioturbation. This study therefore highlights that community bioturbation results from this combination of processes responding to environmental variability at different time-scales. However, community level measurements of bioturbation across environmental variability are still scarce, and BPc is calculated using commonly available data on benthic community structure and the functional classification of invertebrates. Therefore, BPc could be used to support the growth of landscape scale bioturbation research, but future uses of the index need to consider which bioturbation attributes the index actually predicts. As BPc predicts bioturbation distance, estimated here using a random-walk model applicable to community settings, studies using either of the metrics should be directly comparable and contribute to a more integrated future for

  18. Bioavailability and Chronic Toxicity of Metal Sulfide Minerals to Benthic Marine Invertebrates: Implications for Deep Sea Exploration, Mining and Tailings Disposal.

    Science.gov (United States)

    Simpson, Stuart L; Spadaro, David A

    2016-04-01

    The exploration and proposed mining of sulfide massive deposits in deep-sea environments and increased use deep-sea tailings placement (DSTP) in coastal zones has highlighted the need to better understand the fate and effects of mine-derived materials in marine environments. Metal sulfide ores contain high concentrations of metal(loid)s, of which a large portion exist in highly mineralized or sulfidised forms and are predicted to exhibit low bioavailability. In this study, sediments were spiked with a range of natural sulfide minerals (including chalcopyrite, chalcocite, galena, sphalerite) to assess the bioavailability and toxicity to benthic invertebrates (bivalve survival and amphipod survival and reproduction). The metal sulfide phases were considerably less bioavailable than metal contaminants introduced to sediment in dissolved forms, or in urban estuarine sediments contaminated with mixtures of metal(loid)s. Compared to total concentrations, the dilute-acid extractable metal(loid) (AEM) concentrations, which are intended to represent the more oxidized and labile forms, were more effective for predicting the toxicity of the sulfide mineral contaminated sediments. The study indicates that sediment quality guidelines based on AEM concentrations provide a useful tool for assessing and monitoring the risk posed by sediments impacted by mine-derived materials in marine environments. PMID:26937684

  19. Chronic toxicity of water-soluble fractions of fresh and water-leached solvent refined coal-II liquids to a freshwater benthic invertebrate

    Energy Technology Data Exchange (ETDEWEB)

    Dauble, D.D.; Fallon, W.E.; Gray, R.H.; Bean, R.M.

    1981-01-01

    A solvent refined coal (SRC-II) liquid blend (2.9:1, middle to heavy distillate) obtained from a pilot plant was sequentially extracted with water to observe compositional changes in water soluble fractions (WSF). An initial WSF, designed to simulate chemicals present after contact with water, and a water-leached (artificially weathered) WSF, designed to represent conditions after exposure to the aqueous environment were chemically characterized. Toxicities of the two WSFs were compared by observing chronic effects on a freshwater benthic invertebrate, Tanytarsus dissimilis. Survival to emergence was suppressed at 3.0 ppth of the initial WSF and at 9.4 ppth of the artificially weathered WSF. However, based on equal concentrations of organic carbon and phenolics, weathered WSF solutions were three to five times more toxic. Concentrations, relative distributions, and loss over time of phenols and aromatic hydrocarbons differed between aqueous extractions derived from the fresh and weathered SRC II material. Tests assessing long-term effects of complex materials must be designed and interpreted on the basis of organism exposure to compounds most likely to persist in the environment.

  20. 海洋沉积物中重金属对底栖无脊椎动物的生物有效性%Bioavailability of marine sediment-bound heavy metals to benthic invertebrates: A review

    Institute of Scientific and Technical Information of China (English)

    汪飞; 黄小平

    2012-01-01

    Marine sediment is considered as the important sink for heavy metals, while benthic invertebrates can accumulate heavy metals mainly through sediment ingestion. The ingested heavy metals can be transferred through food chain and finally affect human health. This paper summarized the research advances on the bioavailability of marine sedimentary heavy metals to benthic invertebrates, including the uptake pathway for heavy metal assimilation and the sediment geo-chemical and biological factors of governing the bioavailability of heavy metals to benthic invertebrates. Further researches were suggested to focus on the influence of inshore eutrophication on the bioavailability of sediment-bound heavy metals, the physical digestion process in the gut of benthic invertebrates involved with the bioavailability of sediment-bound heavy metals, and the variations of sedimentary heavy metals bioavailability in the whole life history of marine benthic invertebrates.%海洋沉积物是重金属的重要贮库,而海洋底栖无脊椎动物主要从沉积物中摄取重金属,这些被摄取的重金属能够通过食物链进行传递,进而影响到人类健康.本文总结了近些年来在海洋沉积物中重金属对底栖无脊椎动物生物有效性方面的研究进展,包括海洋底栖无脊椎动物对重金属的吸收途径、沉积物地球化学性质和底栖无脊椎动物生理等生物因素对沉积物中重金属生物有效性的影响.在此基础上,展望了未来研究重点,主要包括近海富营养化对沉积物中重金属生物有效性的影响,海洋底栖无脊椎动物消化道中的物理消化过程对沉积物中重金属生物有效性的影响,海洋底栖无脊椎动物整个生活史过程中沉积物中重金属生物有效性的变化等.

  1. Impacts of unusually high sea ice cover on Antarctic coastal benthic food web structure

    OpenAIRE

    Michel, Loïc; Dubois, Philippe; Eleaume,Marc; Fournier, Jérôme; Gallut, Cyril; Jane, Philip; Lepoint, Gilles

    2016-01-01

    Antarctica currently undergoes strong and contrasted impacts linked with climate change. While the West Antarctic Peninsula is one of the most rapidly warming regions in the world, resulting in sea ice cover decrease, the sea ice cover of East Antarctica unexpectedly tends to increase, possibly in relation with changes in atmospheric circulation. Changes in sea ice cover are likely to influence benthic food web structure through modifications of benthic-pelagic coupling, disruption of benthic...

  2. Bio-inspired design of ice-retardant devices based on benthic marine invertebrates: the effect of surface texture

    CERN Document Server

    Mehrabani, Homayun; Tse, Kyle; Evangelista, Dennis

    2014-01-01

    Growth of ice on surfaces poses a challenge for both organisms and for devices that come into contact with liquids below the freezing point. Resistance of some organisms to ice formation and growth, either in subtidal environments (e.g. Antarctic anchor ice), or in environments with moisture and cold air (e.g. plants, intertidal) begs examination of how this is accomplished. Several factors may be important in promoting or mitigating ice formation. As a start, here we examine the effect of surface texture alone. We tested four candidate surfaces, inspired by hard-shelled marine invertebrates and constructed using a three-dimensional printing process. We screened biological and artifical samples for ice formation and accretion in submerged conditions using previous methods, and developed a new test to examine ice formation from surface droplets as might be encountered in environments with moist, cold air. It appears surface texture plays only a small role in delaying the onset of ice formation: a stripe featur...

  3. Bio-inspired design of ice-retardant devices based on benthic marine invertebrates: the effect of surface texture

    Directory of Open Access Journals (Sweden)

    Homayun Mehrabani

    2014-09-01

    Full Text Available Growth of ice on surfaces poses a challenge for both organisms and for devices that come into contact with liquids below the freezing point. Resistance of some organisms to ice formation and growth, either in subtidal environments (e.g., Antarctic anchor ice, or in environments with moisture and cold air (e.g., plants, intertidal begs examination of how this is accomplished. Several factors may be important in promoting or mitigating ice formation. As a start, here we examine the effect of surface texture alone. We tested four candidate surfaces, inspired by hard-shelled marine invertebrates and constructed using a three-dimensional printing process. We examined sub-polar marine organisms to develop sample textures and screened them for ice formation and accretion in submerged conditions using previous methods for comparison to data for Antarctic organisms. The sub-polar organisms tested were all found to form ice readily. We also screened artificial 3-D printed samples using the same previous methods, and developed a new test to examine ice formation from surface droplets as might be encountered in environments with moist, cold air. Despite limitations inherent to our techniques, it appears surface texture plays only a small role in delaying the onset of ice formation: a stripe feature (corresponding to patterning found on valves of blue mussels, Mytilus edulis, or on the spines of the Antarctic sea urchin Sterechinus neumayeri slowed ice formation an average of 25% compared to a grid feature (corresponding to patterning found on sub-polar butterclams, Saxidomas nuttalli. The geometric dimensions of the features have only a small (∼6% effect on ice formation. Surface texture affects ice formation, but does not explain by itself the large variation in ice formation and species-specific ice resistance observed in other work. This suggests future examination of other factors, such as material elastic properties and surface coatings, and their

  4. Bio-inspired design of ice-retardant devices based on benthic marine invertebrates: the effect of surface texture.

    Science.gov (United States)

    Mehrabani, Homayun; Ray, Neil; Tse, Kyle; Evangelista, Dennis

    2014-01-01

    Growth of ice on surfaces poses a challenge for both organisms and for devices that come into contact with liquids below the freezing point. Resistance of some organisms to ice formation and growth, either in subtidal environments (e.g., Antarctic anchor ice), or in environments with moisture and cold air (e.g., plants, intertidal) begs examination of how this is accomplished. Several factors may be important in promoting or mitigating ice formation. As a start, here we examine the effect of surface texture alone. We tested four candidate surfaces, inspired by hard-shelled marine invertebrates and constructed using a three-dimensional printing process. We examined sub-polar marine organisms to develop sample textures and screened them for ice formation and accretion in submerged conditions using previous methods for comparison to data for Antarctic organisms. The sub-polar organisms tested were all found to form ice readily. We also screened artificial 3-D printed samples using the same previous methods, and developed a new test to examine ice formation from surface droplets as might be encountered in environments with moist, cold air. Despite limitations inherent to our techniques, it appears surface texture plays only a small role in delaying the onset of ice formation: a stripe feature (corresponding to patterning found on valves of blue mussels, Mytilus edulis, or on the spines of the Antarctic sea urchin Sterechinus neumayeri) slowed ice formation an average of 25% compared to a grid feature (corresponding to patterning found on sub-polar butterclams, Saxidomas nuttalli). The geometric dimensions of the features have only a small (∼6%) effect on ice formation. Surface texture affects ice formation, but does not explain by itself the large variation in ice formation and species-specific ice resistance observed in other work. This suggests future examination of other factors, such as material elastic properties and surface coatings, and their interaction with

  5. NMR structural determination of unique invertebrate glycosaminoglycans endowed with medical properties.

    Science.gov (United States)

    Pomin, Vitor H

    2015-09-01

    Glycosaminoglycans (GAGs) are sulfated polysaccharides of complex structure endowed with numerous biomedical functions. Although ubiquitously distributed in vertebrates, GAGs can also occur in certain terrestrial or marine invertebrates. Solution nuclear magnetic resonance (NMR) spectroscopy has been the analytical technique mostly employed in structural characterization of GAGs from any source. This review aims at illustrating the application of NMR in structural determination of few representative invertebrate GAG examples of unique structures and endowed with therapeutic actions. They are the holothurian fucosylated chondroitin sulfate, the acharan sulfate isolated from the snail Achatina fulica, the dermatan sulfates with distinct sulfation patterns extracted from ascidian species, the sulfated glucuronic acid-containing heparan sulfate isolated from the gastropode Nodipecten nodosum, and the hybrid heparin/heparan sulfate molecule obtained from the shrimp Litopenaeus vannamei. These invertebrate GAGs exhibit distinct structures when compared to those extracted from mammalian GAGs. The distinct structures of the invertebrate GAGs lead also to different mechanisms of actions as compared to the mammalian GAG standards. Invertebrate GAGs comprise promising therapeutic candidates in fights against diseases. Solution NMR has been playing a pivotal role in this carbohydrate-based drug research, discovery and development. PMID:26083200

  6. Effect of zinc-enriched natural sediments, in isolated and microcosm models, on three species of benthic invertebrates

    International Nuclear Information System (INIS)

    Availability of toxic in aquatic bodies is limited by the physicochemical characteristics of sediments and water, as well as by the interactions between the different xenobiotics and inhabits species. The aim of this work was to relate the effect produced by zinc (Zn) spiked in sediments of the Ignacio Ramirez dam (PIR), in isolated and microcosm models, on ATP concentration of three benthic organisms with the metal biodisponibility. The selected species were a crustacean, an annelid and a mollusk: Hyalella azteca (Amphipoda: Hyalellidae), Limnodrilus hoffmeisteri (Oligochaeta: Tubificidae) and Stagnicola attenuata (Basommatophora: Lymnaeidae), species that are found at high proportions in the reservoir and use different spaces in the benthos. Samples of sediments and organisms were collected from the PIR during the dry season (February of 1999). Metal concentration (Zn, Fe, Cu and Ni), pH, texture, particle size, total nitrogen and organic matter were determined in sediments. Sublethal studies were carried out using two types of static systems (isolated and in microcosm organisms). Both models contained PIR sediments enriched with Zn (nominal concentration of 0.8129 mg/kg) and synthetic water in a proportion of 1:4. The test organisms were added to the systems once the equilibrium was reached (2 hr) considering the biomass quantity with respect to volume (1.0 g of organism by each 100 ml of water:sediment). After 0, 12, 24, 36, 48 and 72 hr of exposure, samples of sediment and hydrobionts were taken, and Zn content was quantified by atomic absorption. ATP concentration was also determined in organisms. The effect produced by natural sediments spiked with Zn is increased by the presence of more than one specie in the system (microcosm). With respect to Zn levels, two of the organisms (L. hoffmeisteri y S. attenuata) tend to lose this metal in isolated and microcosm models, probably as a regulation strategy in its accumulation, as well as Fe presence in the

  7. Diversity and network structure of invertebrate communities associated to Heliconia species in natural and human disturbed tropical rain forests

    OpenAIRE

    Julieta Benítez-Malvido; Ana Paola Martínez-Falcón; Wesley Dáttilo; Ek Del Val

    2014-01-01

    We analyzed the influence of natural and anthropogenic habitat disturbance on the structure of invertebrate communities living on two species of Heliconia herbs. We compared the invertebrate community structure associated to both species growing in natural forest gaps, on road edges for H. latispatha, and in riparian vegetation for H. collinsiana. We assessed the topological structure of individual-based Heliconia–invertebrate networks. Species richness was greater in H. collinsiana inhabitin...

  8. Benthic data for corals, macroalgae, invertebrates, and non-living bottom types from 12 sites in American Samoa, 2005-2009. (NODC Accession 0068364)

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — Benthic transects were repeated at 12 sites around Tutuila at various depths on the reef slopes and flats. Benthic coverage categories include coral species,...

  9. Structure and function of invertebrate Kazal-type serine proteinase inhibitors.

    Science.gov (United States)

    Rimphanitchayakit, Vichien; Tassanakajon, Anchalee

    2010-04-01

    Proteinases and proteinase inhibitors are involved in several biological and physiological processes in all multicellular organisms. The proteinase inhibitors function as modulators for controlling the extent of deleterious proteinase activity. The Kazal-type proteinase inhibitors (KPIs) in family I1 are among the well-known families of proteinase inhibitors, widely found in mammals, avian and a variety of invertebrates. Like those classical KPIs, the invertebrate KPIs can be single or multiple domain proteins containing one or more Kazal inhibitory domains linked together by peptide spacers of variable length. All invertebrate Kazal domains of about 40-60 amino acids in length share a common structure which is dictated by six conserved cysteine residues forming three intra-domain disulfide cross-links despite the variability of amino acid sequences between the half-cystines. Invertebrate KPIs are strong inhibitors as shown by their extremely high association constant of 10(7)-10(13)M(-1). The inhibitory specificity of a Kazal domain varies widely with a different reactive P(1) amino acid. Different invertebrate KPI domains may arise from gene duplication but several KPI proteins can also be derived from alternative splicing. The invertebrate KPIs function as anticoagulants in blood-sucking animals such as leech, mosquitoes and ticks. Several KPIs are likely involved in protecting host from microbial proteinases while some from the parasitic protozoa help protecting the parasites from the host digestive proteinase enzymes. Silk moths produce KPIs to protect their cocoon from predators and microbial destruction. PMID:19995574

  10. Effect of woodstack structure on invertebrate abundance and diversity

    OpenAIRE

    Sands, R. J.

    2013-01-01

    Reduced quantities of dead wood in managed forests have resulted in a reduction in the abundance and diversity of saproxylic invertebrates to the extent that many are now considered red list species. To mitigate against this loss, one conservation measure is the provision of dead wood, in the form of piles of chopped logs, i.e. ‘woodstacks’. The heterogeneity and volume of dead wood habitat is considered to be an important component of habitat suitability. However, the value of different wood...

  11. [Impact of Mikania micrantha invasion on soil meso- and micro-invertebrate community structure].

    Science.gov (United States)

    Quan, Guo-ming; Zhang, Jia-en; Xie, Jun-fang; Mao, Dan-juan; Xu, Hua-qin; Jiang, Wan-bing; Wen, Du-juan

    2011-07-01

    Mikania micrantha, a notorious exotic weed of Asteraceae family, has invaded successfully in southern China, and caused serious damages to native ecosystems. In this paper, a field survey was conducted in the Huolushan Forest Park of Guangzhou, China, aimed to understand the impact of M. micrantha invasion on the soil meso- and micro-invertebrate community. Three sampling sites were installed, including M. micrantha-invaded site, ecotone, and native vegetation site. Through four samplings in 2009, a total of 5206 soil meso- and micro-invertebrate individuals were collected, belonging to 4 phyla, 10 classes, and 19 orders, among which, Nematoda was the dominant group, and Acarina, Collembolan, and Rotifera were the common groups. M. micrantha invasion altered the characteristics of soil meso- and micro-invertebrate community structure. Compared with those at the other two sampling sites, the numbers of total individuals, Nematoda, and Acarina at M. micrantha-invaded site increased significantly, but the groups of soil meso- and micro-invertebrates had less change. At M. micrantha-invaded site, the density-group index (DG) of soil meso- and micro-invertebrates was significantly higher, Margalef richness index (D) and Simpson dominance index (C) tended to ascend, but Pielou evenness index (E) and Shannon index (H') tended to descend. The similarity coefficient of soil meso- and micro-invertebrate community between M. micrantha-invaded site and ecotone was higher than that between M. micrantha-invaded site and native vegetation site. The changes of local climate conditions, plant litters, root secretions, and soil physical-chemical properties caused by M. micrantha invasion could be the major contributing factors that altered the community structure of soil meso- and micro-invertebrates at M. micrantha-invaded site. PMID:22007466

  12. Patterns in the horizontal structure of litter invertebrate communities in windbreak plantations in the steppe zone of the Ukraine

    OpenAIRE

    Faly Ludmyla; Brygadyrenko Viktor

    2014-01-01

    The article analyses the patterns in the horizontal structure of litter invertebrate communities in windbreak plantations in the Steppe zone of the Ukraine. The number of invertebrate species shows statistically insignificant changes depending on the extent of the litter horizon development. With an increase in litter mass from 300 to 900 g/m2 the number of invertebrate species increases. An increase in the total number of macrofauna is observed in areas having a minimum and maximum ...

  13. Diversity and network structure of invertebrate communities associated to Heliconia species in natural and human disturbed tropical rain forests

    Directory of Open Access Journals (Sweden)

    Julieta Benítez-Malvido

    2014-12-01

    Full Text Available We analyzed the influence of natural and anthropogenic habitat disturbance on the structure of invertebrate communities living on two species of Heliconia herbs. We compared the invertebrate community structure associated to both species growing in natural forest gaps, on road edges for H. latispatha, and in riparian vegetation for H. collinsiana. We assessed the topological structure of individual-based Heliconia–invertebrate networks. Species richness was greater in H. collinsiana inhabiting riparian vegetation but no differences were found in the diversity of invertebrates for any Heliconia species and habitat. Invertebrate abundance was greater in gaps for H. latispatha and in riparian vegetation for H. collinsiana showing a species turnover in human disturbed habitats. The invertebrate community was not randomly assembled but highly nested, revealing a structured pattern for all habitat conditions. Heliconia–invertebrate network properties appear to be maintained in human disturbed habitats, despite differences in species richness, abundance and composition and host number and quality. Our study contributes to the understanding of the structure of ecological interactions in contrasting habitats. Because they provide food and habitat for the associated fauna and several microhabitats for colonization, heliconias could be used as habitat elements for invertebrate conservation in human impacted landscapes.

  14. Influence of Detritus on the Structure of the Invertebrate Community in a Small Portuguese Stream

    OpenAIRE

    González, M.; Graça, Manuel A. S.

    2005-01-01

    This study tests if the coarse particulate organic matter (CPOM) mass was related to the invertebrate community structure in riffles and sandy pools of a fourth-order reach of a stream after partialling out the effects of physical characteristics of the sampled patches. Diversity and structure of the assemblages differed between habitats. In both, CPOM mass was positively correlated with total density and with all functional feeding groups excepting filterers. Redundancy analyses and variance...

  15. Biogeography of Nearshore Subtidal Invertebrates in the Gulf of Maine

    Science.gov (United States)

    The biogeography of nearshore benthic invertebrates in the Gulf of Maine was studied to compare recent data with historical biogeographic studies, define physical-chemical factors affecting species distributions, and provide information needed to calibrate benthic indices of envi...

  16. Photographic Images of Benthic Coral, Algae, and Invertebrate Species in Marine Habitats and Subhabitats around Offshore Islets in the Main Hawaiian Islands 2007 (NODC Accession 0043046)

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — The marine algae, invertebrate and fish communities were surveyed at ten islet or offshore island sites in the Main Hawaiian Islands in the vicinity of Lanai, (Puu...

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

    International Nuclear Information System (INIS)

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

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

    Energy Technology Data Exchange (ETDEWEB)

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

    2013-12-15

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

  19. Trophic structure of the benthic invertebrate community in the littoral zone of a mountain cascade system

    Directory of Open Access Journals (Sweden)

    M. Prus

    2002-02-01

    Full Text Available The cascade of Solina/Myczkowce dam reservoirs situated in the West Carpathian Mts was investigated. The cascade consists of two reservoirs, the upper one built 35 yr ago on the San and Solinka Rivers of 2100 ha area separated from another one, of 190 ha area, with hypolimnion cold water supplied from the upper one.

    The offshore zone was investigated monthly (6 sites of upper, 3 sites of lower reservoir using a tube bottom sampler. Besides numbers, biomass and biodiversity indices, the proportion of predators, plant/detritus-feeders and filter-feeders was assessed.

    In upper reservoir Solina, with a lack of filter-feeders, a clear preponderance of plant-detritus feeders was observed. Predators, consisting mostly of leeches and hydranchnellids were present. In lower reservoir Myczkowce, all three trophic classes were present in the first year of study in almost equal proportions and in 1998 with slight preponderance of plant/detritus feeders was observed.

    The Oligochaeta/Chironomidae index in both reservoirs was low, indicating low degree of eutrophication. Only one site in Solina reservoir (near a fish culture and one in Myczkowce (influenced by tourist activity showed a high value of this index.

  20. Trophic structure of the benthic invertebrate community in the littoral zone of a mountain cascade system

    OpenAIRE

    Prus, M.; P. Bijok; Prus, T.

    2002-01-01

    The cascade of Solina/Myczkowce dam reservoirs situated in the West Carpathian Mts was investigated. The cascade consists of two reservoirs, the upper one built 35 yr ago on the San and Solinka Rivers of 2100 ha area separated from another one, of 190 ha area, with hypolimnion cold water supplied from the upper one.

    The offshore zone was investigated monthly (6 sites of upper, 3 sites of lower reservoir) using a tube bottom sampler. Besides numbers, biomass and biod...

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

    Energy Technology Data Exchange (ETDEWEB)

    Lagauzere, S.

    2008-06-15

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

  2. Do artificial structures alter marine invertebrate genetic makeup?

    OpenAIRE

    Fauvelot, Cecile; Costantini, Federica; Virgilio, Massimiliano; Abbiati, Marco

    2012-01-01

    Human-made structures are increasingly built in marine coastal habitats for a variety of purposes. Offshore oil and gas production platforms are among the largest examples. Yet, biological effects of these increasing density artificial substrata are under evaluated. The objective of our study is to investigate the possible role of offshore platforms in modifying the genetic composition of populations of natural rocky shores species. The serpulid Pomatoceros triqueter was used as a model, and ...

  3. WATER QUALITY EVALUATION OF CRIŞUL ALB AND CRIŞUL NEGRU RIVERS CATCHMENTS, FROM CODRU-MOMA MOUNTAINS (WEST OF ROMANIA, USING BENTHIC INVERTEBRATES COMMUNITIES

    Directory of Open Access Journals (Sweden)

    Andreea VARGA

    2010-01-01

    Full Text Available Water quality evaluation of the two watersheds involved the collection of thirteen samples from the tributaries of Crişul Alb and Crişul Negru rivers. The samples were collected in june 2010 with a benthic net, which had the mesh size of 250 µm, by disturbing the substrate, being thus qualitative samples. To get an overview, a series of physical-chemical parameters (water temperature, pH, oxygen, conductivity, cyanide, nitrates, nitrites, phosphates was studied in parallel with the study of benthic community. In most of the sampling points the major group of benthic macroinvertebrates were found and in some EPT group (Ephemeroptera, Plecoptera, Trichoptera prevailed even, which is known as a clean freshwater group, sensitive to pollution and human impact.

  4. Use of stable isotope ratios to delineate coastal benthic food web structure in Adélie Land (East Antarctica)

    OpenAIRE

    Michel, Loïc; Dubois, Philippe; Eleaume,Marc; Fournier, Jérôme; Gallut, Cyril; Jane, Philip; Lepoint, Gilles

    2016-01-01

    Antarctica currently undergoes strong and contrasted impacts linked with climate change. While the West Antarctic Peninsula is one of the most rapidly warming regions in the world, resulting in sea ice cover decrease, in some parts of East Antarctica sea ice cover tends to increase, possibly in relation with changes in atmospheric circulation. Changes in sea ice cover are likely to influence benthic food web structure through modifications of benthic-pelagic coupling, disruption of benthic pr...

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

    Czech Academy of Sciences Publication Activity Database

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

    2012-01-01

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

  6. Marine Invertebrate assemblages in southern California

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — This is a point file of invertebrate site clusters calculated from benthic trawls completed by the Southern California Coastal Water Research Project (SCCWRP). Data...

  7. Community Structure and Distribution Pattern of Intertidal Invertebrate Macrofauna at Some Anthropogenically Influenced Coasts of Kathiawar Peninsula (India)

    OpenAIRE

    Poonam Bhadja; Paresh Poriya; Rahul Kundu

    2014-01-01

    Present communication reports the community structure and distribution pattern of intertidal invertebrate macrofauna at four shores of the Kathiawar peninsular coastline off the Arabian Sea (India). The selected shores have different levels of human activities. Present report tests three hypotheses; that is, (i) distribution of invertebrate macrofauna in these shores is influenced by space and time, (ii) abiotic factors have a profound influence on the distribution pattern of intertidal macro...

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

    Institute of Scientific and Technical Information of China (English)

    陈凯; 肖能文; 王备新; 李俊生

    2012-01-01

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

  9. Effect of canopy density on litter invertebrate community structure in pine forests

    OpenAIRE

    Brygadyrenko Viktor V.

    2016-01-01

    We investigated the structure of the litter invertebrate community in 141 pine (Pinus sylvestris Linnaeus, 1753) forest sites with five variants of canopy density (30-44, 45-59, 60-74, 75-89 and 90-100%) in the steppe zone of Ukraine. The total number of litter macrofauna specimens collected at each site decreased from an average of 84/100 trap-days in the sparsest stands (30-40% density) to 4-39 specimens/100 trap-days in the forests with a denser canopy. The number of macrofauna species cau...

  10. Invertebrate footprints on detritus processing, bacterial community structure, and spatiotemporal redox profiles

    OpenAIRE

    Hunting, E.R.; Whatley, M. H.; Geest, van der, A.H.M.; Mulder, C; Kraak, M.H.S.; Breure, A M; Admiraal, W.

    2012-01-01

    Detritus processing is driven by a complex interplay between macroinvertebrate and microbial activities. Bioturbation/feeding activities of invertebrates in sediments are known to influence decomposition rates. However, direct effects of invertebrates on bacterial communities and detritus processing remain ill-defined, mainly because identifying interactions between invertebrates and sediments is methodologically challenging. We incubated 5 macroinvertebrate species with various bioturbation/...

  11. Photothermal and Structural Comparative Analysis of Chitinous Exoskeletons of Marine Invertebrates

    Science.gov (United States)

    Juárez-de la Rosa, B. A.; Yañez-Limón, J. M.; Tiburcio-Moreno, J. A.; Zambrano, M.; Ardisson, P.-L.; Quintana, P.; Alvarado-Gil, J. J.

    2012-11-01

    Chitinous materials are common in nature and provide different functions including protection and support of many invertebrate animals. Exoskeletons in these organisms constitute the boundary regulating interaction between the animal and the external environment. For this reason, it is important to study the physical properties of these skeletons, in particular, thermal properties. The objective of this study is to investigate the thermal diffusivity of the skeletons of four species of marine invertebrates, Antipathes caribbeana (black coral), Panulinus argus (lobster), Callinectes sapidus (crab), and Limulus polyphemus (xiphosure). Thermal characterization is performed using photothermal radiometry (PTR) and laser-flash techniques. The measurements are complemented with structural characterization using X-ray diffraction. The results using both laser flash and PTR are consistent. These indicate that the thermal properties are strongly dependent on the presence of biogenic minerals (calcium and/or magnesium) and on the crystallinity index of the structure. The thermal-diffusivity values show an increase as a function of the crystallinity index.

  12. Importance of benthic production to fish populations in Lake Mead prior to the establishment of quagga mussels

    Science.gov (United States)

    Umek, John; Chandra, Sudeep; Rosen, Michael; Wittmann, Marion; Sullivan, Joe; Orsak, Erik

    2010-01-01

    Limnologists recently have developed an interest in quantifying benthic resource contributions to higher-level consumers. Much of this research focuses on natural lakes with very little research in reservoirs. In this study, we provide a contemporary snapshot of the food web structure of Lake Mead to evaluate the contribution of benthic resources to fish consumers. In addition, we document the available food to fishes on soft sediments and changes to the invertebrate community over 2 time periods. Benthic invertebrate food availability for fishes is greater in Las Vegas Bay than Overton Arm. Las Vegas Bay is dominated by oligochaetes, whose biomass increased with depth, while Overton Arm is dominated by chironomids, whose biomass did not change with depth. Diet and isotopic measurements indicate the fish community largely relies on benthic resources regardless of basin (Las Vegas Bay >80%; Overton Arm >92%); however, the threadfin shad likely contribute more to largemouth and striped bass production in Overton Arm versus Las Vegas Bay. A 2-time period analysis, pre and post quagga mussel establishment and during lake level declines, suggests there is no change in the density of benthic invertebrates in Boulder Basin, but there were greater abundances of select taxa in this basin by season and depth than in other basins. Given the potential of alterations as a result of the expansion of quagga mussel and the reliance of the fishery on benthic resources, future investigation of basin specific, benthic processes is recommended.

  13. 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

    Under the ongoing climate change, understanding the mechanisms structuring the spatial distribution of aquatic species in glacial stream networks is of critical importance to predict the response of aquatic biodiversity in the face of glacier melting. In this study, we propose to use metacommunity...... theory as a conceptual framework to better understand how river network structure influences the spatial organization of aquatic communities in glacierized catchments. At 51 stream sites in an Andean glacierized catchment (Ecuador), we sampled benthic macroinvertebrates, measured physico.......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...

  14. Effects of a bactericide on the structure and survival of benthic diatom communities

    OpenAIRE

    Morin, S.; Proia, L.; Ricart, M.; Bonnineau, C.; Geiszinger, A.; Ricciardi, F.; Guasch, H.; Romani, A.M.; Sabater, S.

    2010-01-01

    We studied the adverse effects of triclosan, a widely used biocide commonly reported in surface waters, on the structure and function of benthic diatom communities. Laboratory-grown biofilms were exposed (i) to chronic contamination by increasing concentrations of triclosan and (ii) to a short-pulse of sublethal triclosan concentrations followed by a 2-week recuperation period. The first experiment was performed using 6 nominal concentrations ranging from 0.05 to 500 µg/L triclosan to obtain ...

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

    Science.gov (United States)

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

    2012-01-01

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

  16. Invertebrate colonization of leaves and roots within sediments of intermittent coastal plain streams across hydrologic phases

    Science.gov (United States)

    We compared benthic invertebrate assemblages colonizing three types of buried substrates (leaves, roots and plastic roots) among three intermittent Coastal Plain streams over a one year period. Invertebrate density was significantly lower in root litterbags than in plastic root l...

  17. SPECIES DIFFERENCES IN ANDROGEN AND ESTROGEN RECEPTOR STRUCTURE AND FUNCTION AMONG VERTEBRATES AND INVERTEBRATES: INTERSPECIES EXTRAPOLATIONS REGARDING ENDOCRINE DISRUPTING CHEMICALS

    Science.gov (United States)

    Species Differences in Androgen and Estrogen Receptor Structure and Function Among Vertebrates and Invertebrates: Interspecies Extrapolations regarding Endocrine Disrupting Chemicals VS Wilson1, GT Ankley2, M Gooding 1,3, PD Reynolds 1,4, NC Noriega 1, M Cardon 1, P Hartig1,...

  18. Patterns of the benthic community structure in coral reefs of the north western Caribbean

    OpenAIRE

    Borges-Souza, J.M.; Chávez, E.A.

    2007-01-01

    Data on the benthic community structure of six coral reefs of the Mexican portion of the Mesoamerican Barrier Reef System using the photographic-transect method, aimed to describe the structural patterns in each reef, and comparing differences between shallow and deep reefs. In the shallow stratum (Colombia 6-7m, Chankanaab 6m, Majahual 1-6m and Akumal 8m) hexacorals, sponges and algae dominated, with 38%, 34.6% and 14.5% of abundance, respectively. The species most commonly found were: Monta...

  19. Effect of canopy density on litter invertebrate community structure in pine forests

    Directory of Open Access Journals (Sweden)

    Brygadyrenko Viktor V.

    2016-03-01

    Full Text Available We investigated the structure of the litter invertebrate community in 141 pine (Pinus sylvestris Linnaeus, 1753 forest sites with five variants of canopy density (30-44, 45-59, 60-74, 75-89 and 90-100% in the steppe zone of Ukraine. The total number of litter macrofauna specimens collected at each site decreased from an average of 84/100 trap-days in the sparsest stands (30-40% density to 4-39 specimens/100 trap-days in the forests with a denser canopy. The number of macrofauna species caught in the pitfall traps does not vary significantly with different degrees of canopy density. The Shannon-Weaver and Pielou diversity indexes show increases corresponding to increasing stages of canopy density. The average share of phytophages in the trophic structure of the litter macrofauna does not vary with canopy density. The relative number of saprophages decreases from 54% in the forests with the sparsest canopy to 11-13% in the forests with denser canopies. The relative number of saprophages in pine forests (22% is lower than that in deciduous forests (40%. The share of zoophages in the trophic structure of the litter macrofauna increases significantly with the increase in the pine forest canopy density (from 21% in the sparsest plots to 59% in the densest. The relative number of polyphages is highest (47-65% when the canopy density is 45-89%. At canopy densities below or above this range, the share of polyphages in the community decreases to 20 and 24%, respectively. Regardless of canopy density, Formicidae and Lycosidae invariably rank amongst the first three dominant families. Nine families of invertebrates dominate in the pine forest stands with the highest density (90-100%, and 5-7 families dominate in the stands with lower density. For the pine forest litter macrofauna, we have observed an extreme simplification of the community size structure compared with natural and planted deciduous forests of the steppe zone of Ukraine.

  20. Structural analysis of the α subunit of Na(+)/K(+) ATPase genes in invertebrates.

    Science.gov (United States)

    Thabet, Rahma; Rouault, J-D; Ayadi, Habib; Leignel, Vincent

    2016-01-01

    The Na(+)/K(+) ATPase is a ubiquitous pump coordinating the transport of Na(+) and K(+) across the membrane of cells and its role is fundamental to cellular functions. It is heteromer in eukaryotes including two or three subunits (α, β and γ which is specific to the vertebrates). The catalytic functions of the enzyme have been attributed to the α subunit. Several complete α protein sequences are available, but only few gene structures were characterized. We identified the genomic sequences coding the α-subunit of the Na(+)/K(+) ATPase, from the whole-genome shotgun contigs (WGS), NCBI Genomes (chromosome), Genomic Survey Sequences (GSS) and High Throughput Genomic Sequences (HTGS) databases across distinct phyla. One copy of the α subunit gene was found in Annelida, Arthropoda, Cnidaria, Echinodermata, Hemichordata, Mollusca, Placozoa, Porifera, Platyhelminthes, Urochordata, but the nematodes seem to possess 2 to 4 copies. The number of introns varied from 0 (Platyhelminthes) to 26 (Porifera); and their localization and length are also highly variable. Molecular phylogenies (Maximum Likelihood and Maximum Parsimony methods) showed some clusters constituted by (Chordata/(Echinodermata/Hemichordata)) or (Plathelminthes/(Annelida/Mollusca)) and a basal position for Porifera. These structural analyses increase our knowledge about the evolutionary events of the α subunit genes in the invertebrates. PMID:26812300

  1. Is benthic food web structure related to diversity of marine macrobenthic communities?

    Science.gov (United States)

    Sokołowski, A.; Wołowicz, M.; Asmus, H.; Asmus, R.; Carlier, A.; Gasiunaité, Z.; Grémare, A.; Hummel, H.; Lesutiené, J.; Razinkovas, A.; Renaud, P. E.; Richard, P.; Kędra, M.

    2012-08-01

    Numerical structure and the organisation of food webs within macrozoobenthic communities has been assessed in the European waters (Svalbard, Barents Sea, Baltic Sea, North Sea, Atlantic Ocean and the Mediterranean Sea) to address the interactions between biodiversity and ecosystem functioning. Abundance and classical species diversity indices (S, H', J) of macrofaunal communities were related to principal attributes of food webs (relative trophic level and food chain length, FCL) that were determined from carbon and nitrogen stable isotope values. Structure of marine macrobenthos varies substantially at a geographical scale; total abundance ranges from 63 ind. m-2 to 34,517 ind. m-2, species richness varies from 3 to 166 and the Shannon-Weaver diversity index from 0.26 to 3.26 while Pielou's evenness index is below 0.73. The major source of energy for macrobenthic communities is suspended particulate organic matter, consisting of phytoplankton and detrital particles, sediment particulate organic matter, and microphytobenthos in varying proportions. These food sources support the presence of suspension- and deposit-feeding communities, which dominate numerically on the sea floor. Benthic food webs include usually four to five trophic levels (FCL varies from 3.08 to 4.86). Most species are assigned to the second trophic level (primary consumers), fewer species are grouped in the third trophic level (secondary consumers), and benthic top predators are the least numerous. Most species cluster primarily at the lowest trophic level that is consistent with the typical organization of pyramidal food webs. Food chain length increases with biodiversity, highlighting a positive effect of more complex community structure on food web organisation. In more diverse benthic communities, energy is transferred through more trophic levels while species-poor communities sustain a shorter food chain.

  2. MICRO-INVERTEBRATE COMMUNITY STRUCTURE WITHIN A MARITIME ANTARCTIC LAKE (Eleventh Symposium on Polar Biology)

    OpenAIRE

    Sandra J., McINNES; J. Cynan, ELLIS-EVANS

    1990-01-01

    The data set discussed here was obtained from a transect across a depth profile in Sombre Lake (Signy Island, South Orkney Islands). The fauna, composed of benthonic micro-invertebrates, was readily observed grazing on the surface of the cyanobacterial mats that form a thin cover on the surface of the sediments. Algal mat composition varied in response to factors such as light, climate, and ice scour. Micro-invertebrate species diversity was limited, but population numbers were high. The resu...

  3. Disjoint geographical distribution of intertidal and nearshore benthic invertebrates in the Southern Hemisphere Distribuciones geográficas disyuntas de invertebrados bentónicos intermareales y del submareal somero en el Hemisferio Sur

    Directory of Open Access Journals (Sweden)

    JUAN C CASTILLA

    2000-12-01

    Full Text Available Biogeographical explanations for the extant and paleo disjoint geographical distribution in the southern hemisphere of five species of nearshore marine benthic invertebrates: Gaimardia trapesina, Ostrea chilensis, Pyura stolonifera taxonomic complex, Aulacomya ater and Concholepas concholepas, showing distinctive reproductive strategies and early life history characteristics are reviewed and analyzed. Through the use of published and new information we contrasted the following hypotheses: a vicariance-historical process, b epiplanktonic larval dispersal, c juvenile/adult dispersal through rafting and d planned or accidental anthropogenic dispersal mechanisms. The juvenile/adult transoceanic dispersal hypothesis by rafting was the only one impossible to be rejected for the species analyzed. The implication and future direction for research in this area are discussedSe revisa y analiza las posibles explicaciones para la distribución geográfica disyunta, presente y pasada, en el hemisferio sur de cinco especies de invertebrados bentónicos marinos litorales: Gaimardia trapesina, Ostrea chilensis, el complejo taxonómico Pyura stolonifera, Aulacomya ater y Concholepas concholepas, con estrategias reproductivas y características de historia de vida distintas. Se discute y pone a prueba, usando información original o publicada, las siguientes hipótesis: a procesos históricos de vicarianza, b dispersión de larvas epi-planctónicas, c dispersión de juveniles o adultos por transporte pasivo y d dispersión antropogénica planificada o accidental. La hipótesis de dispersión transoceánica de juveniles o adultos fue la única imposible de rechazar para las especies analizadas. Se discute las direcciones futuras de investigación en esta área

  4. Bioassessment of wet-weather pollution impacts on fine sediments in urban waters by benthic indices and the sediment quality triad.

    Science.gov (United States)

    Lafont, M; Grapentine, L; Rochfort, Q; Marsalek, J; Tixier, G; Breil, P

    2007-01-01

    Benthic invertebrate assessments can be used to gauge the impact of urban wet-weather flows in receiving waters. Experiences from Cemagref in France have shown that standardized benthic indices (e.g. Oligochaete Index of Sediment Bioindication - IOBS) can be used to reliably determine the ecological status of urban streams and can be incorporated into the new European Water Framework Directive. The Canadian studies on streams and stormwater ponds using chemical analyses, benthic toxicity testing and benthic invertebrate community structure (i.e. the sediment quality triad) comparisons have shown that toxicity was more likely to occur in ponds at sites with higher concentrations of heavy metals and heavier polycyclic aromatic hydrocarbons, and at greater water depths, where fine sediments from urban runoff accumulated. A more comprehensive evaluation of wet-weather flow impacts could be obtained by combining approaches from both countries. PMID:18025726

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

    Science.gov (United States)

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

  6. Benthic ammonia oxidizers differ in community structure and biogeochemical potential across a riverine delta.

    Science.gov (United States)

    Damashek, Julian; Smith, Jason M; Mosier, Annika C; Francis, Christopher A

    2014-01-01

    Nitrogen pollution in coastal zones is a widespread issue, particularly in ecosystems with urban or agricultural watersheds. California's Sacramento-San Joaquin Delta, at the landward reaches of San Francisco Bay, is highly impacted by both agricultural runoff and sewage effluent, leading to chronically high nutrient loadings. In particular, the extensive discharge of ammonium into the Sacramento River has altered this ecosystem by vastly increasing ammonium concentrations and thus changing the stoichiometry of inorganic nitrogen stocks, with potential effects throughout the food web. This debate surrounding ammonium inputs highlights the importance of understanding the rates of, and controls on, nitrogen (N) cycling processes across the delta. To date, however, there has been little research examining N biogeochemistry or N-cycling microbial communities in this system. We report the first data on benthic ammonia-oxidizing microbial communities and potential nitrification rates for the Sacramento-San Joaquin Delta, focusing on the functional gene amoA (which codes for the α-subunit of ammonia monooxygenase). There were stark regional differences in ammonia-oxidizing communities, with ammonia-oxidizing bacteria (AOB) outnumbering ammonia-oxidizing archaea (AOA) only in the ammonium-rich Sacramento River. High potential nitrification rates in the Sacramento River suggested these communities may be capable of oxidizing significant amounts of ammonium, compared to the San Joaquin River and the upper reaches of San Francisco Bay. Gene diversity also showed regional patterns, as well as phylogenetically unique ammonia oxidizers in the Sacramento River. The benthic ammonia oxidizers in this nutrient-rich aquatic ecosystem may be important players in its overall nutrient cycling, and their community structure and biogeochemical function appear related to nutrient loadings. Unraveling the microbial ecology and biogeochemistry of N cycling pathways, including benthic

  7. The human impact on benthic community structure and dynamics of different ecosystems from Lunca Mureșului Nature Park (West of Romania

    Directory of Open Access Journals (Sweden)

    Andreea A. Marin

    2011-01-01

    Full Text Available The anthropic impact, which takes various forms, changes the water quality parameters anddisturb the living environment of benthic macroinvertebrates. The present study aims to track the waypollution sources influence the macrozoobenthic community. Collecting quantitative samples, at differentseasons, from Mureș River and Cărămidăriei Lake, within the area of Lunca Mureșului Nature Park beforeand after each major pollution source, shows the way pollution affects, both qualitatively andquantitatively, the community of benthic invertebrates. 9 groups of benthic invertebrates were identified,their density, abundance and frequency undergoing changes from one station to another and from oneseason to another. When the river flows through the park, the benthic community reflects strong waterquality degradation of Mureș River. The river, naturally flowing on a long distance allows, through theself-purification process, an improvement in water quality emphasized by the occurrence of somesensitive groups to pollution which disappear completely once the tributary stream Mureșelul and othernon-purified waters from the town of Pecica flow into the river. The seasonal dynamics of dominantgroups (Oligochaeta, Diptera-Chironomidae suggests a similarity, recording high values within theautumn-winter time interval.

  8. 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....

  9. Community Structure and Distribution Pattern of Intertidal Invertebrate Macrofauna at Some Anthropogenically Influenced Coasts of Kathiawar Peninsula (India

    Directory of Open Access Journals (Sweden)

    Poonam Bhadja

    2014-01-01

    Full Text Available Present communication reports the community structure and distribution pattern of intertidal invertebrate macrofauna at four shores of the Kathiawar peninsular coastline off the Arabian Sea (India. The selected shores have different levels of human activities. Present report tests three hypotheses; that is, (i distribution of invertebrate macrofauna in these shores is influenced by space and time, (ii abiotic factors have a profound influence on the distribution pattern of intertidal macrofaunal assemblages, and (iii human activities influence the community structure of the intertidal invertebrate macrofauna at these shores. To test these hypotheses, spatiotemporal variations in different ecological indices were studied. A total of 60 species from six phyla were considered for the study. High species diversity was recorded during winter and monsoon seasons in almost all the shores studied. It was also evident that a few environmental factors had a cumulative influence on the distribution pattern of intertidal macrofauna. Significant spatial variations in the species diversity and evenness were also observed. Though the shores studied have similar coast characteristics and climatic conditions, they face different levels of human activities. Therefore, the observed variations in the intertidal faunal assemblage were possibly caused by anthropogenic stress.

  10. Variation in composition of macro-benthic invertebrates as an indication of water quality status in three bays in Lake Victoria

    OpenAIRE

    Sekiranda, S.K.; Okot-Okumu, J.; Bugenyi, F.W.B.; Ndawula, L.M.; Gandhi, P.

    2004-01-01

    Knowledge of how biota can be used to monitor ecosystem health and assess impacts by human alterations such as land use and management measures taken at different spatial scales is critical for improving the ecological quality of aquatic ecosystems. This knowledge in Uganda is very limited or unavailable yet it is needed to better understand the relationship between environmental factors at different spatial scales, assemblage structure and taxon richness of aquatic ecosystems. In this study,...

  11. Laboratory measurements of scalar and momentum structure in turbulent aquatic benthic boundary layers

    Science.gov (United States)

    Dombroski, Daniel Edward

    In aquatic benthic environments, hydrodynamic transport of mass and momentum have shaped the evolution of form-function relationships. Animals whose life cycle depends on success in such environments have developed the biological structure and behavioral mechanisms to sustain dynamic stresses and complex chemical signals. It has become increasingly clear that understanding the ecology of these organisms is dependent on examining the complexities of the turbulent environment. In this dissertation, hydrodynamics and the structure of chemical signals within turbulent boundary layer flows are examined in the context of natural and biological systems. Experiments were conducted in the benthic region of a water flume using a combination of point-measurement and full-field imaging techniques. There are three areas of focus within the complete body of work: (1) The accuracy of an acoustic measurement technique commonly used in natural flows was evaluated. Errors in the technique, primarily attributed to a sampling volume that is large relative to the scales of motion in turbulent flows, were found to be larger than and extend farther from the bed than previously reported. (2) A three-dimensional laser-based imaging system was developed for quantifying turbulent scalar structure. The system was employed to study the topology and orientation of structure within a bed-level, passively released scalar plume. (3) Hydrodynamic stresses were measured near marine fouling communities in a study aimed at predicting larval settlement probabilities. Turbulent stresses, and by extension, the suitability of microhabitats, were found to be highly dependent on local topography and outer-scale flow conditions. This body of work advances the field of experimental fluid mechanics by contributing to the development of methods for quantifying turbulent flows, as well as furthering current understanding of the capabilities and limitations associated with new and existing techniques. Statistical

  12. Grazing management in saltmarsh ecosystems drives invertebrate diversity, abundance and functional group structure

    OpenAIRE

    Ford, Hilary; Garbutt, Angus; Jones, Laurence; Davey L Jones

    2013-01-01

    1. Saltmarsh conservation management often involves livestock grazing to maximise plant diversity and provide suitable breeding habitat for over-wintering coastal birds. The effect of grazing on invertebrates is rarely quantified, but results from limited studies of terrestrial and coastal grasslands demonstrate greater abundance and species richness in un-grazed grassland. 2. The impact of short sward (

  13. Patchiness of macrobenthic invertebrates in homogenized intertidal habitats: hidden spatial structure at a landscape scale

    OpenAIRE

    Kraan, Casper; Meer, Jaap van der; Dekinga, Anne; Piersma, Theunis; Lipcius, Romuald

    2009-01-01

    Many terrestrial habitats, and certainly man-made systems such as woodland and agricultural habitats, are characterised by a mosaic of different habitat types. In contrast, most seafloors have a rather uniform visual appearance which is enhanced by the cryptic nature of many of their inhabitants. The present study aimed to: (1) describe landscape scale spatial patterns of benthic infauna after evaluating 3 methods for analyzing auto correlations (Moran's I, semivariance and fractals), (2) com...

  14. Benthic Ammonia Oxidizers Differ in Community Structure and Biogeochemical Potential Across a Riverine Delta

    Directory of Open Access Journals (Sweden)

    Julian eDamashek

    2015-01-01

    Full Text Available Nitrogen pollution in coastal zones is a widespread issue, particularly in ecosystems with urban or agricultural watersheds. California’s Sacramento-San Joaquin Delta, at the landward reaches of San Francisco Bay, is highly impacted by both agricultural runoff and sewage effluent, leading to chronically high nutrient loadings. In particular, the massive discharge of ammonium into the Sacramento River has altered this ecosystem by increasing ammonium concentrations and thus changing the stoichiometry of inorganic nitrogen stocks, with potential effects throughout the food web. To date, however, there has been little research examining N biogeochemistry or N-cycling microbial communities in this system. We report the first data on benthic ammonia-oxidizing microbial communities and potential nitrification rates for the Sacramento-San Joaquin Delta, focusing on the functional gene amoA (encoding the α-subunit of ammonia monooxygenase. There were stark regional differences in ammonia-oxidizing communities, with ammonia-oxidizing bacteria (AOB outnumbering ammonia-oxidizing archaea (AOA only in the ammonium-rich Sacramento River. High potential nitrification rates in the Sacramento River suggested these communities may be capable of oxidizing significant amounts of ammonium, compared to the San Joaquin River and the upper reaches of San Francisco Bay. Gene diversity also showed regional patterns, as well as phylogenetically unique ammonia oxidizers in the Sacramento River. The community structure and biogeochemical function of benthic ammonia oxidizers appears related to nutrient loadings. Unraveling the microbial ecology and biogeochemistry of N cycling pathways is a critical step toward understanding how such ecosystems respond to the changing environmental conditions wrought by human development and climate change.

  15. Diel variability in seawater pH relates to calcification and benthic community structure on coral reefs.

    Directory of Open Access Journals (Sweden)

    Nichole N Price

    Full Text Available Community structure and assembly are determined in part by environmental heterogeneity. While reef-building corals respond negatively to warming (i.e. bleaching events and ocean acidification (OA, the extent of present-day natural variability in pH on shallow reefs and ecological consequences for benthic assemblages is unknown. We documented high resolution temporal patterns in temperature and pH from three reefs in the central Pacific and examined how these data relate to community development and net accretion rates of early successional benthic organisms. These reefs experienced substantial diel fluctuations in temperature (0.78°C and pH (>0.2 similar to the magnitude of 'warming' and 'acidification' expected over the next century. Where daily pH within the benthic boundary layer failed to exceed pelagic climatological seasonal lows, net accretion was slower and fleshy, non-calcifying benthic organisms dominated space. Thus, key aspects of coral reef ecosystem structure and function are presently related to natural diurnal variability in pH.

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

    Science.gov (United States)

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

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

    Science.gov (United States)

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

    2005-05-01

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

  18. Spatial variation in population structure and its relation to movement and the potential for dispersal in a model intertidal invertebrate.

    Directory of Open Access Journals (Sweden)

    Trevor T Bringloe

    Full Text Available Dispersal, the movement of an individual away from its natal or breeding ground, has been studied extensively in birds and mammals to understand the costs and benefits of movement behavior. Whether or not invertebrates disperse in response to such attributes as habitat quality or density of conspecifics remains uncertain, due in part to the difficulties in marking and recapturing invertebrates. In the upper Bay of Fundy, Canada, the intertidal amphipod Corophium volutator swims at night around the new or full moon. Furthermore, this species is regionally widespread across a large spatial scale with site-to-site variation in population structure. Such variation provides a backdrop against which biological determinants of dispersal can be investigated. We conducted a large-scale study at nine mudflats, and used swimmer density, sampled using stationary plankton nets, as a proxy for dispersing individuals. We also sampled mud residents using sediment cores over 3 sampling rounds (20-28 June, 10-17 July, 2-11 August 2010. Density of swimmers was most variable at the largest spatial scales, indicating important population-level variation. The smallest juveniles and large juveniles or small adults (particularly females were consistently overrepresented as swimmers. Small juveniles swam at most times and locations, whereas swimming of young females decreased with increasing mud presence of young males, and swimming of large juveniles decreased with increasing mud presence of adults. Swimming in most stages increased with density of mud residents; however, proportionally less swimming occurred as total mud resident density increased. We suggest small juveniles move in search of C. volutator aggregations which possibly act as a proxy for better habitat. We also suggest large juveniles and small adults move if potential mates are limiting. Future studies can use sampling designs over large spatial scales with varying population structure to help

  19. Structure and Dynamics of North-western Mediterranean Rocky Benthic Communities along a Depth Gradient

    Science.gov (United States)

    Garrabou, J.; Ballesteros, E.; Zabala, M.

    2002-09-01

    The structure and dynamics of four Mediterranean communities along a depth gradient (5 to 20 m depth) were investigated. The main environmental factors relevant to the organization of benthic communities varied predictably with depth, decreasing both in magnitude and in temporal variability. The following hypotheses were tested on the organization of communities as depth increases: (1) community structure increases in complexity, (2) community dynamics decrease, and (3) temporal (seasonal) variations both in community structure and dynamics become dampened. A series of photographs (310 cm2 each) of 12 permanent plots were taken monthly over a 2-year period. Plots belonged to one of four communities, two algal- and two animal-dominated by animals. In the analysis of photographs, a novel methodological approach was employed using techniques borrowed from landscape ecology. Community structure was quantified using three landscape pattern indices: number of patches, mean patch size and Shannon's diversity index. Community dynamics were measured by calculating spatially explicit area changes over time by overlaying drawings corresponding to different sampling times. The results support the hypotheses tested. Firstly, the shallower, algae-dominated communities, had, in general, significantly lower structure (i.e. patch-mosaics were less heterogeneous), than were deeper communities dominated by animals. Secondly, community dynamics were significantly larger in shallower communities than in deeper communities. Thirdly, temporal changes in community structure and dynamics were generally dampened with depth showing, in some cases, significant temporal patterns in structure and dynamics, which were consistent with seasonal variations. These depth-related trends in community structure and dynamics in subtidal Mediterranean communities may respond to strong changes in community determining factors (nutrient availability, physical disturbance, predation). Finally, it is

  20. Photographic images of benthic coral, algae and invertebrate species in marine habitats and subhabitats around offshore islets in the main Hawaiian Islands, April 2 - September 20, 2007 (NODC Accession 0043046)

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — The marine algae, invertebrate and fish communities were surveyed at ten islet or offshore island sites in the Main Hawaiian Islands in the vicinity of Lanai, (Puu...

  1. Examination of Algal Diversity and Benthic Community Structure at Palmyra Atoll, U.S. Line Islands

    Data.gov (United States)

    US Fish and Wildlife Service, Department of the Interior — Palmyra Atoll National Wildlife Refuge is the second largest atoll under U.S. jurisdiction in the Pacific Ocean. Until recently, little was known about benthic...

  2. Low concentrations, potential ecological consequences: Synthetic estrogens alter life-history and demographic structures of aquatic invertebrates

    International Nuclear Information System (INIS)

    Contraceptive drugs are nowadays found in aquatic environments around the globe. Particularly, 17α-ethinylestradiol (EE2) may act even at low concentrations, such as those recorded in natural ecosystems. We evaluated the physiological effects of EE2 on cyclopoids and calanoids, common copepods in both marine and freshwater communities. We used three EE2 concentrations and assessed its impact on activity of different physiological endpoints: Acetylcholinesterase (neurotransmission), Glutathione S-transferase (detoxifying system), and Caspase-3 (apoptosis). While EE2 exerts, distinctive effect on detoxifying and apoptotic systems, no effect on AChE was observed at environmental doses. Our results show that EE2 exposure affects differently copepod physiology endpoints, altering moulting process, adult recruitment in calanoids and calanoid to cyclopoid ratio. The ecological consequences of this underlying physiological process may affect since life history to population and community structures, and this represent a new aspects of this xenobiotic in natural systems. Highlights: •We evaluated physiological effects of 17α-ethinylestradiol (EE2) on copepods. •We measured the EE2 effect on neurotransmission, detoxifying system and apoptosis. •EE2 exert distinctive effect on detoxifying and apoptotic systems. •EE2 affects differently calanoids and cyclopoids moulting and adult recruitment. •Physiological impact in invertebrates' communities is a novel aspect of EE2 effects. -- Anthropogenic estrogens modify the physiological functioning of aquatic invertebrates

  3. Novel circular single-stranded DNA viruses identified in marine invertebrates reveal high sequence diversity and consistent predicted intrinsic disorder patterns within putative structural proteins

    Directory of Open Access Journals (Sweden)

    Karyna eRosario

    2015-07-01

    Full Text Available Viral metagenomics has recently revealed the ubiquitous and diverse nature of single-stranded DNA (ssDNA viruses that encode a conserved replication initiator protein (Rep in the marine environment. Although eukaryotic circular Rep-encoding ssDNA (CRESS-DNA viruses were originally thought to only infect plants and vertebrates, recent studies have identified these viruses in a number of invertebrates. To further explore CRESS-DNA viruses in the marine environment, this study surveyed CRESS-DNA viruses in various marine invertebrate species. A total of 27 novel CRESS-DNA genomes, with Reps that share less than 60.1% identity with previously reported viruses, were recovered from 21 invertebrate species, mainly crustaceans. Phylogenetic analysis based on the Rep revealed a novel clade of CRESS-DNA viruses that included approximately one third of the marine invertebrate associated viruses identified here and whose members may represent a novel family. Investigation of putative capsid proteins (Cap encoded within the eukaryotic CRESS-DNA viral genomes from this study and those in GenBank demonstrated conserved patterns of predicted intrinsically disordered regions (IDRs, which can be used to complement similarity-based searches to identify divergent structural proteins within novel genomes. Overall, this study expands our knowledge of CRESS-DNA viruses associated with invertebrates and explores a new tool to evaluate divergent structural proteins encoded by these viruses.

  4. Prediction of benthic community structure from environmental variables in a soft-sediment tidal basin (North Sea)

    Science.gov (United States)

    Puls, W.; van Bernem, K.-H.; Eppel, D.; Kapitza, H.; Pleskachevsky, A.; Riethmüller, R.; Vaessen, B.

    2012-09-01

    The relationship between benthos data and environmental data in 308 samples collected from the intertidal zone of the Hörnum tidal basin (German Wadden Sea) was analyzed. The environmental variables were current velocity, wave action, emersion time (all of which were obtained from a 2-year simulation with a numerical model) and four sediment grain-size parameters. A grouping of sample stations into five benthos clusters showed a large-scale (>1 km) zoning of benthic assemblages on the tidal flats. The zoning varied with the distance from the shore. Three sample applications were examined to test the predictability of the benthic community structure based on environmental variables. In each application, the dataset was spatially partitioned into a training set and a test set. Predictions of benthic community structure in the test sets were attempted using a multinomial logistic regression model. Applying hydrodynamic predictors, the model performed significantly better than it did when sediment predictors were applied. The accuracy of model predictions, given by Cohen's kappa, varied between 0.14 and 0.49. The model results were consistent with independently attained evidence of the important role of physical factors in Wadden Sea tidal flat ecology.

  5. The effect of freshwater canal discharge on the stability of two seagrass benthic communities in Biscayne National Park, Florida

    OpenAIRE

    Brook, I. M.

    1982-01-01

    A two-year study in western Biscayne National Park, Florida examined two benthic communities which were affected by pulse discharge of freshwater from drainage canals. One community, in a dense shoal-grass meadow (Halodule wrightii ), still had not returned to its initial structure after eighteen months following the first major freshwater inflow during the study. Invertebrate abundance never recovered its former levels, while dominance shifted from amphipods in the high abundance period to m...

  6. Roebuck Bay Invertebrate and bird Mapping 2006

    OpenAIRE

    Piersma, Theunis; Pearson, Grant B.; Hickey, Robert; Dittmann, Sabine; Rogers, Danny I.; Folmer, Eelke; Honkoop, Pieter; Drent, Jan; de Goeij, Petra; 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 Roebuck Bay and the shorebirds that depend on this food resource. The northern mudflats previously had been benthically mapped in 1997, 2000 and 2002. In addition to the mapping efforts, as a reach-out ...

  7. Impact of flow conditions on ammonium uptake and microbial community structure in benthic biofilms

    Science.gov (United States)

    Arnon, Shai; Yanuka, Keren; Nejidat, Ali

    2010-05-01

    Excess nitrogen in surface waters is widely recognized to be a major global problem that adversely affects ecosystems, human health, and the economy. Today, most efforts to understand and model nutrient dynamics at large scales relies on macro-scale parameterization, such as mean channel geometry and velocity with uniform flow assumptions, as well as gross averages of in-situ nutrient transformation rates. However, there is increasing evidence that nutrient transformations in hyporheic zone are regulated by coupling between physical, chemical, and microbiological processes. Ignoring this greatly hinders the estimation of average biochemical transformation rates under the variable flow conditions found in aquatic systems. We used a combination of macro- and micro-scale observations in laboratory flumes to show that interplay between hydrodynamic transport, redox gradients, and microbial metabolism controls ammonium utilization by hyporheic microbial communities. Biofilm structural characteristics were quantified using denaturing gradient gel electrophoresis (DGGE) and real time PCR, while redox and pH gradients were measured using microelectrodes. We found that overlying velocities had profound effect on ammonium uptake due to mass transfer of ammonium from the bulk water to the benthic biofilms, but also due to the delivery of oxygen into the sediment bed. Under laminar flow conditions we didn't observe any change of ammonium uptake as a response to increase in overlying velocity. However, under non-laminar conditions we observe monotonic increase in ammonium uptake, with the greatest uptake under the fastest flow condition. We will discuss ammonium uptake rates results in the context of the different microbial communities and the micro-scale observations that were obtained using the microelectrodes. We anticipate that combined knowledge of the response of the microbial community and bulk nitrogen utilization rates to flow conditions will support the development of

  8. Diversity and ecological structure of vibrios in benthic and pelagic habitats along a latitudinal gradient in the Southwest Atlantic Ocean

    Directory of Open Access Journals (Sweden)

    Luciane A. Chimetto Tonon

    2015-02-01

    Full Text Available We analyzed the diversity and population structure of the 775 Vibrio isolates from different locations of the southwestern Atlantic Ocean (SAO, including St. Peter and St. Paul Archipelago (SPSPA, Abrolhos Bank (AB and the St. Sebastian region (SS, between 2005 and 2010. In this study, 195 novel isolates, obtained from seawater and major benthic organisms (rhodoliths and corals, were compared with a collection of 580 isolates previously characterized (available at www.taxvibrio.lncc.br. The isolates were distributed in 8 major habitat spectra according to AdaptML analysis on the basis of pyrH phylogenetic reconstruction and ecological information, such as isolation source (i.e., corals: Madracis decactis, Mussismilia braziliensis, M. hispida, Phyllogorgia dilatata, Scolymia wellsi; zoanthids: Palythoa caribaeorum, P. variabilis and Zoanthus solanderi; fireworm: Hermodice carunculata; rhodolith; water and sediment and sampling site regions (SPSPA, AB and SS. Ecologically distinct groups were discerned through AdaptML, which finds phylogenetic groups that are significantly different in their spectra of habitat preferences. Some habitat spectra suggested ecological specialization, with habitat spectra 2, 3, and 4 corresponding to specialization on SPSPA, AB, and SS, respectively. This match between habitat and location may reflect a minor exchange of Vibrio populations between geographically isolated benthic systems. Moreover, we found several widespread Vibrio species predominantly from water column, and different populations of a single Vibrio species from H. carunculata in ecologically distinct groups (H-1 and H-8 respectively. On the other hand, AdaptML detected phylogenetic groups that are found in both the benthos and in open water. The ecological grouping observed suggests dispersal and connectivity between the benthic and pelagic systems in AB. This study is a first attempt to characterize the biogeographic distribution of vibrios in both

  9. Relationships between aquatic invertebrates, water quality and vegetation in an Andean peatland system

    Directory of Open Access Journals (Sweden)

    E. Oyague Passuni

    2015-12-01

    Full Text Available Peatlands (known as bofedales in the Peruvian Andes provide important social and environmental services in the Peruvian Puna ecoregion, especially as sources of water and forage for domestic livestock. In biological terms, these peatlands are key habitats with their own community structure, dynamics and interactions; and they serve as biodiversity hotspots within the High Andes. In this article we assess the relationships between: (i physical structure, (ii water quality, (iii plant communities and (iv the assemblages of aquatic invertebrates (benthic macroinvertebrates in three peatlands located in Cuzco Region, southern Peru. The results suggest that the benthic macroinvertebrate assemblage is a good indicator of the trophic status of the small pools that are typically present in bofedales. Trophic status is, in turn, primarily related to spatial and seasonal water availability and the types of plant communities present in each peatland.

  10. Benthic Cover

    Data.gov (United States)

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

  11. Benthic ecology of the northeastern Chukchi Sea. Part I. Environmental characteristics and macrofaunal community structure, 2008-2010

    Science.gov (United States)

    Blanchard, Arny L.; Parris, Carrie L.; Knowlton, Ann L.; Wade, Nicole R.

    2013-09-01

    Spatial variations of processes driving macrofaunal distributions can arise from interactions among topographic features and oceanographic patterns, and are not understood at small scales in the northeastern Chukchi Sea. Benthic macrofauna and environmental characteristics were measured to determine factors driving macrofaunal distributions as part of a multidisciplinary environmental program in the northeastern Chukchi Sea from 2008 to 2010. Macrofauna were sampled in three study areas, named Klondike, Burger, and Statoil, with a van Veen grab at up to 82 stations each year, as well as an area where marine mammals were seen feeding. The macrofaunal assemblages in all study areas were similar in species-composition with deposit-feeding polychaetes (53% of density and of 26% biomass) and bivalves (15% of density and 52% of biomass) collectively the most prominent groups. Maldane sarsi dominated the polychaetes in terms of both density and biomass, while bivalves were numerically dominated by Ennucula tenuis, but their biomass was dominated by larger species such as Macoma calcarea and Astarte borealis. Exceptions occurred in the marine mammal feeding area that was dominated by amphipods (71% of density and 30% biomass). Average densities were higher in Burger than in Klondike or Statoil, while biomass values were similar between Burger and Statoil, and higher in these two study areas than in Klondike. Overall, the distributions, biomass and density of benthic macrofauna reflect the high volume of production reaching the seafloor in the shallow waters of the Chukchi Sea. Variations in community structure among study areas were correlated with water depth and bottom-water temperature. Short-term temporal differences in community structure covaried with interannual oceanographic variations that may have altered food availability, macrofaunal survival, or larval recruitment. Topographic control over circulation appears to be a primary driver in structuring benthic

  12. A study of radionuclide transfer between invertebrates and their marine sedimentary environment

    International Nuclear Information System (INIS)

    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 60Co, 137Cs and accessorily 59Fe and 144Ce. 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 60Co 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

  13. Community structure and benthic habitats across the George V Shelf, East Antarctica: Trends through space and time

    Science.gov (United States)

    Post, Alexandra L.; Beaman, Robin J.; O'Brien, Philip E.; Eléaume, Marc; Riddle, Martin J.

    2011-03-01

    Physical and biological characteristics of benthic communities are analysed from underwater video footage collected across the George V Shelf during the 2007/2008 CEAMARC voyage. Benthic habitats are strongly structured by physical processes operating over a range of temporal and spatial scales. Iceberg scouring recurs over timescales of years to centuries along shallower parts of the shelf, creating communities in various stages of maturity and recolonisation. Upwelling of modified circumpolar deep water (MCDW) onto the outer shelf and cross-shelf flow of high-salinity shelf water (HSSW) create spatial contrasts in nutrient and sediment supply, which are largely reflected in the distribution of deposit- and filter-feeding communities. Long-term cycles in the advance and retreat of icesheets (over millennial scales) and subsequent focussing of sediments in troughs such as the Mertz Drift create patches of consolidated and soft sediments, which also provide distinct habitats for colonisation by different biota. These physical processes of iceberg scouring, current regimes and depositional environments, in addition to water depth, are important factors in the structure of benthic communities across the George V Shelf. The modern shelf communities mapped in this study largely represent colonisation over the past 8000-12,000 years, following retreat of the icesheet and glaciers at the end of the last glaciation. Recolonisation on this shelf may have occurred from two sources: deep-sea environments and possible shelf refugia on the Mertz and Adélie Banks. However, any open-shelf area would have been subject to intense iceberg scouring. Understanding the timescales over which shelf communities have evolved and the physical factors which shape them will allow better prediction of the distribution of Antarctic shelf communities and their vulnerability to change. This knowledge can aid better management regimes for the Antarctic margin.

  14. Structure and dynamics of a benthic trophic web in a Mediterranean seasonal stream

    Directory of Open Access Journals (Sweden)

    Patrizia Elena Vannucchi

    2013-10-01

    Full Text Available In this work we present the results of a study conducted on the benthic macroinvertebrate community of a Southern Spain seasonal stream over a year. We constructed the food web focusing on the benthic fauna and we studied the ecology and dynamics of the community in terms of trophic resources. The benthic trophic web was composed by 35 families; these were not all present at the same time, but were incorporating and disappearing throughout the study period. Connectance between trophospecies varied from 0.24 to 0.59. The functional feeding group (FFG composition of the community turned out to be fairly constant with time with a predominance of scrapers and collector-gatherers. Furthermore, data obtained from the Bray-Curtis measure and the niche overlap study, evidence the stability of the stream from a trophic point of view. Rather widespread is omnivory that plays an important role in the survival of some families. We compared the results of the trophic web study with those of other temporary streams of the same region of Southern Spain.

  15. Benthic macrofauna

    Digital Repository Service at National Institute of Oceanography (India)

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

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

  16. Caracterización preliminar de los invertebrados bentónicos capturados accidentalmente en la pesca de camarones en el norte del estado de Río de Janeiro, sudeste de Brasil Preliminary characterization of benthic invertebrates caught as by-catch in the shrimp fishery in the north of the Rio de Janeiro State, southeastern Brazil

    Directory of Open Access Journals (Sweden)

    Igor David da Costa

    2009-01-01

    Full Text Available Para caracterizar la biodiversidad de invertebrados bentónicos que componen la fauna asociada a la pesca de camarones en el puerto del Farol de Sao Thomé, costa norte del estado de Río de Janeiro, se realizaron 11 pescas mensuales en el año 2004 con redes de arrastre de fondo, cuya área de operaciones comprende 3-5 mn desde la línea de costa, entre 22°00'S y 22°20'S. Los datos registrados de cada taxon y/o especie se refieren a la frecuencia de ocurrencia, frecuencia numérica, biomasa, índice de Importancia Relativa y abundancia. En total se registraron 27 especies de invertebrados bentónicos de Porifera, Cnidaria, Mollusca, Annelida, Crustácea, Echinodermata y Bryozoa. Crustácea fue el más representativo, tanto en número de ejemplares de Petrochirus diogenes, Hepatus pudibundus y Callinectes ornatos, como en biomasa de P. diogenes y H. pudibundas. En términos de frecuencia de ocurrencia en los muéstreos, 11 especies (40,7% fueron constantes; 6 (22,2% accesorias y 10 (37,0% accidentales.In order to characterize the biodiversity of the benthic invertebrate by-catch associated with the shrimp fishery at Farol de Sao Thome harbor, northern Rio de Janeiro State, Brazil, in 2004, 11 monthly trawls were conducted using bottom trawl nets between 22°00'S and 22°20'S and from 3 to 5 nm from the shoreline. The analyzed data for each talon and/or species include frequency of occurrence, numeric frequency, biomass, index of Relative Importance, and abundance. In total, 27 benthic invertebrate species were recorded, including Peripheral, Cnidarians, Mollusk, Annelid, Crustacea, Echinodermata, and Bryozoa. The most representative group was Crustacea, both in number of specimens (Petrochirus diogenes, Hepatus pudibundus, Callinectes ornatus and in biomass (P. diogenes, H. pudibundus. In terms of the frequency of occurrence in the samples, 11 species (40.7% were constant, 6 species (22.2% were accessories, and 10 species (37.0% were by-catch.

  17. Thermal analysis and structural characterization of chitinous exoskeleton from two marine invertebrates

    Energy Technology Data Exchange (ETDEWEB)

    Juárez-de la Rosa, B.A., E-mail: balej05@yahoo.com.mx [Laboratory of Natural Polymers, CIAD – Coordinación Guaymas, Carretera al Varadero Nacional km. 6.6, Col. Las Playitas, 85480 Guaymas, Sonora (Mexico); Applied Physics Department, CINVESTAV-IPN Unidad Mérida, Carretera antigua a Progreso, km. 6. Apdo, Postal 73, Cordemex, 97310 Mérida, Yucatan (Mexico); May-Crespo, J.; Quintana-Owen, P.; Gónzalez-Gómez, W.S. [Applied Physics Department, CINVESTAV-IPN Unidad Mérida, Carretera antigua a Progreso, km. 6. Apdo, Postal 73, Cordemex, 97310 Mérida, Yucatan (Mexico); Yañez-Limón, J.M. [Materials and Engineering Science, CINVESTAV-IPN, Unidad Querétaro, Libramiento Norponiente No. 2000, Fracc. Real de Juriquilla, 76230 Santiago de Querétaro, Querétaro (Mexico); Alvarado-Gil, J.J., E-mail: jjag@mda.cinvestav.mx [Applied Physics Department, CINVESTAV-IPN Unidad Mérida, Carretera antigua a Progreso, km. 6. Apdo, Postal 73, Cordemex, 97310 Mérida, Yucatan (Mexico)

    2015-06-20

    Highlights: • Thermal analysis of exoskeletons: Antipathes caribbeana and Limulus polyphemus. • DMTA revealed Limulus has a stronger structure with a stepper glass transition. • DSC measurements exhibited a much larger water holding capacity in Antipathes. • X-ray diffraction analysis shows a higher crystallinity index in Limulus • FTIR showed α-chitin structures and high temperature C–N groups prevalence. - ABSTRACT: Thermomechanical and structural properties of two marine species exoskeletons, Antipathes caribbeana (black coral) and Limulus polyphemus (xiphosure), were studied using dynamic mechanical thermal analysis (DMTA), differential scanning calorimetry (DSC), and thermogravimetric analysis (TGA). DMTA curves indicate the viscoelastic behavior and glass transition around 255 °C, black coral presented a second transition (175 °C) associated to the acetamide group attached to the α-chitin chain. DSC measurements showed a endothermic peak around 100 °C, with enthalpies of 4.02 and 118.04 J/g, indicating strong differences between exoskeletons respect to their water holding capacity and strength water–polymer interaction. A comparative analysis involving DSC and X-ray diffraction showed that lower values ΔH in xiphosure correspond to a material with a higher crystallinity (30), in contrast black coral exhibits higher values ΔH and a lower crystallinity (19). FTIR confirmed α-chitin based structure, at higher temperature diminishes the amide bands and a new one appears, related to C–N groups.

  18. Thermal analysis and structural characterization of chitinous exoskeleton from two marine invertebrates

    International Nuclear Information System (INIS)

    Highlights: • Thermal analysis of exoskeletons: Antipathes caribbeana and Limulus polyphemus. • DMTA revealed Limulus has a stronger structure with a stepper glass transition. • DSC measurements exhibited a much larger water holding capacity in Antipathes. • X-ray diffraction analysis shows a higher crystallinity index in Limulus • FTIR showed α-chitin structures and high temperature C–N groups prevalence. - ABSTRACT: Thermomechanical and structural properties of two marine species exoskeletons, Antipathes caribbeana (black coral) and Limulus polyphemus (xiphosure), were studied using dynamic mechanical thermal analysis (DMTA), differential scanning calorimetry (DSC), and thermogravimetric analysis (TGA). DMTA curves indicate the viscoelastic behavior and glass transition around 255 °C, black coral presented a second transition (175 °C) associated to the acetamide group attached to the α-chitin chain. DSC measurements showed a endothermic peak around 100 °C, with enthalpies of 4.02 and 118.04 J/g, indicating strong differences between exoskeletons respect to their water holding capacity and strength water–polymer interaction. A comparative analysis involving DSC and X-ray diffraction showed that lower values ΔH in xiphosure correspond to a material with a higher crystallinity (30), in contrast black coral exhibits higher values ΔH and a lower crystallinity (19). FTIR confirmed α-chitin based structure, at higher temperature diminishes the amide bands and a new one appears, related to C–N groups

  19. Demonstrating That Habitat Structure Facilitates Coexistence of Prey & Predator: A Laboratory Investigation Using Goldfish & Invertebrates.

    Science.gov (United States)

    Stewart, Timothy W.; Embrey, Tracey R.

    2003-01-01

    Presents a laboratory investigation to demonstrate that habitat structure promotes increased organism abundance and species diversity by reducing predator effects on prey abundance. Investigates the effects of goldfish (Carassius auratus) predators on Gammarus sp. (an amphipod) and Daphnia magna (a cladoceran) prey in the absence and presence of a…

  20. Stream invertebrate communities of Mongolia: current structure and expected changes due to climate change

    OpenAIRE

    Maasri, Alain; Gelhaus, Jon

    2012-01-01

    Background Mongolia’s riverine landscape is divided into three watersheds, differing in extent of permafrost, amount of precipitation and in hydrological connectivity between sub-drainages. In order to assess the vulnerability of macroinvertebrate communities to ongoing climate change, we consider the taxonomic and functional structures of stream communities in two major watersheds: The Central Asian Internal Watershed (CAIW) and the Arctic Ocean Watershed (AOW), together covering 86.1% of Mo...

  1. 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; Jacobsen, Dean; Dangles, Olivier

    2015-01-01

    Under the ongoing climate change, understanding the mechanisms structuring the spatial distribution of aquatic species in glacial stream networks is of critical importance to predict the response of aquatic biodiversity in the face of glacier melting. In this study, we propose to use metacommunity...... species in headwater streams, and preventing non-adapted species to colonize throughout the entire stream network. Under a scenario of glacier runoff decrease, we expect a reduction in both environmental filtering and dispersal limitation, inducing a taxonomic homogenization of the aquatic fauna in...

  2. Pacific Remote Islands MNM: Initial Survey Instructions for Benthic Marine Cryptobiota

    Data.gov (United States)

    US Fish and Wildlife Service, Department of the Interior — The purpose of the survey is to expand knowledge of the biodiversity of benthic marine invertebrates that are poorly known and are generally not identified in more...

  3. Characterization of benthic types in the lower Medway estuary, Kent. [Nereis diversicolor; Polydora ciliata; Spiophanes bombyx; Hydrobia ulvae; Peloacolex benedeni; Capitella capitatus; Heteromastus filiformis; Caulleriella zetlandica

    Energy Technology Data Exchange (ETDEWEB)

    Wharfe, J.R.

    1976-09-01

    A number of sediment parameters, including particle size and redox potential profiles, were measured during an ecological study of the benthic invertebrate macrofauna of the lower Medway estuary, Kent. The results proved more meaningful in characterizing the sediment habitats of the benthic invertebrate fauna than did measurements on the overlying water.

  4. Ontogenetic variations in the diet of two invasive gobies, Neogobius melanostomus (Pallas, 1814) and Ponticola kessleri (Günther, 1861), from the middle Danube (Slovakia) with notice on their potential impact on benthic invertebrate communities.

    Science.gov (United States)

    Števove, Barbora; Kováč, Vladimír

    2016-07-01

    In this study, ontogenetic variations in diet of invasive bighead goby Ponticola kessleri and round goby Neogobius melanostomus from the middle Danube were analysed. Index of stomach fullness, Fulton's condition factor, index of food importance, frequency of occurrence, biomass, electivity, and proportions of invasive organisms in their diet were examined. Changes in the diet during ontogeny of both species emphasise the differences in their trophic niches. Our results combined with literary data suggest that bighead goby may threaten small native benthic fish species as a predator (especially in the invasion front), whereas round goby can potentially impact native fish species of all ontogenetic phases by competing for food. Round goby appear to have strong impact on bivalves, especially in the invasion front. High consumption of invasive organisms by bighead goby may help the native macroinvertebrate community. Thus, in contrast to round goby, bighead goby does not seem to be a hot candidate for being a nuisance invader. PMID:27031302

  5. Benthic Community Structure and Sediment Geochemical Properties at Hydrocarbon Seeps Along the Continental Slope of the Western North Atlantic

    Science.gov (United States)

    Demopoulos, A. W.; Bourque, J. R.; Brooke, S.

    2015-12-01

    Hydrocarbon seeps support distinct benthic communities capable of utilizing reduced chemical compounds for nutrition. In recent years, methane seepage has been increasingly documented along the continental slope of the U.S. Atlantic margin. In 2012 and 2013, two seeps were investigated in this region: a shallow site near Baltimore Canyon (410-450 m) and a deep site near Norfolk Canyon (1600 m). Both sites contain extensive mussel beds and microbial mats. Sediment cores and grab samples were collected to quantify the abundance, diversity, and community structure of benthic macrofauna (>300 mm) in relationship to the associated sediment environment (organic carbon and nitrogen, stable isotopes 13C and 15N, grain size, and depth) of mussel beds, mats, and slope habitats. Macrofaunal densities in microbial mats were four times greater than those present in mussel beds and slope sediments. Macrofaunal communities were distinctly different both between depths and among habitat types. Specifically, microbial mat sediments were dominated by the annelid families Dorvilleidae, Capitellidae, and Tubificidae, while mussel habitats had higher proportions of crustaceans. Diversity was lower in Baltimore microbial mat habitats, but higher in mussel and slope sediments compared to Norfolk seep habitats found at deeper depths. Multivariate statistical analysis identified sediment carbon:nitrogen (C:N) ratios and 13C values as important variables for structuring the macrofaunal communities. Higher C:N ratios were present within microbial mat habitats and depleted 13C values occurred in sediments adjacent to mussel beds found in Norfolk Canyon seeps. Differences in the quality and source of organic matter present in the seep habitats are known to be important drivers in macrofaunal community structure and associated food webs. The multivariate analysis provides new insight into the relative importance of the seep sediment quality in supporting dense macrofaunal communities compared

  6. Evaluating Ecological Risk to Invertebrate Receptors from PAHs in Sediments at Hazardous Waste Sites (External Review Draft)

    Science.gov (United States)

    In March 2004, ORD's Ecological Risk Assessment Support Center (ERASC) received a request from the Ecological Risk Assessment Forum (ERAF) relating to the evaluation of ecological risk to vertebrate and benthic invertebrate receptors from polycyclic aromatic hydrocarbon compounds...

  7. Long-term changes in invertebrate size structure and composition in a boreal headwater lake with a known minnow introduction

    Directory of Open Access Journals (Sweden)

    Andrew L. Labaj

    2013-03-01

    Full Text Available To determine the extent and timescale of predation impacts occurring in a historically fishless headwater lake near Sudbury, Canada, we surveyed the larval remains of the invertebrate predator Chaoborus and the pelagic cladoceran Bosmina, within a 210Pb dated lake sediment core. Size measures of fossil Bosmina mucros, carapaces, and antennules provided inferences of predation intensity. We observed two notable shifts of predation over the span of our ~500 year record. First, in the late-1800s, a considerable reduction in Bosmina mucro length (an indication of reduced invertebrate predation occurred following centuries of stable, but high invertebrate predation intensity. Nearly concurrent with reduced invertebrate predation was a substantial decline in sedimentary-inferred chlorophyll a (a measure of primary production. We hypothesize that turn-of-the century climate warming resulted in a shift in the dominant lake stratification regime at our study site, thus impacting both invertebrate predation intensity and overall primary production. Second, following an observed minnow introduction in the 1980s, the Chaoborus assemblage experienced a minor shift from larger-to smaller-bodied species, and total chaoborid concentrations were generally the lowest and most stable of the record. C. americanus was not extirpated from the lake, despite large growth in the minnow population. Although C. americanus is a reliable indicator of fishless conditions when obligate planktivorous fish are considered, our data suggest that absolute fishless conditions may be difficult to establish with confidence using the presence of C. americanus mandibles alone, as this taxon can co-exist with minnow species that are not solely planktivorous. Our paleolimnological investigation provides temporal insight on predator-prey interactions occurring in small, shallow headwater lakes that have experienced historic shifts in predation due to long-term environmental change as well

  8. Benthic foraminifera

    Digital Repository Service at National Institute of Oceanography (India)

    Saraswat, R.; Nigam, R.

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

  9. Application of the Benthic Ecosystem Quality Index 2 to benthos in Dutch transitional and coastal waters

    NARCIS (Netherlands)

    Loon, van W.M.G.M.; Boon, A.R.; Gittenberger, A.; Walvoort, D.J.J.; Lavaleye, M.; Duineveld, G.C.A.; Verschoor, A.J.

    2015-01-01

    The Benthic Ecosystem Quality Index 2 (BEQI2) is the Dutch multi-metric index (MMI) for assessing the status and trend of benthic invertebrates in transitional and coastal waters for the Water Framework Directive (WFD). It contains the same indicators, i.e. species richness, Shannon index and AMB

  10. Application of the Benthic Ecosystem Quality Index 2 to benthos in Dutch transitional and coastal waters

    NARCIS (Netherlands)

    Van Loon, W.M.G.M.; Boon, A.R.; Gittenberger, A.; Walvoort, D.J.J.; Lavaleye, M.S.S.; Duineveld, G.C.A.; Verschoor, A.J.

    2015-01-01

    The Benthic Ecosystem Quality Index 2 (BEQI2) is the Dutch multi-metric index (MMI) for assessing the status and trend of benthic invertebrates in transitional and coastal waters for the Water Framework Directive (WFD). It contains the same indicators, i.e. species richness, Shannon index and AMBI,

  11. Changes in epilithic biomasses and invertebrate community structure over a deposit metal concentration gradient in upland headwater streams

    OpenAIRE

    Macintosh, Katrina Ann; Griffiths, David

    2015-01-01

    Stream bed metal deposits affect the taxon richness, density and taxonomic diversity of primary and secondary producers by a variety of direct or indirect abiotic and biotic processes but little is known about the relative importance of these processes over a deposit metal concentration gradient. Inorganic matter (IM), algal and non-photosynthetic detrital (NPD) dry biomasses were estimated for 10 monthly samples, between 2007 and 2008, from eight sites differing in deposit density. Invertebr...

  12. Effects of wild fish and motile epibenthic invertebrates on the benthos below an open water fish farm

    Science.gov (United States)

    Sanz-Lázaro, Carlos; Belando, María Dolores; Navarrete-Mier, Francisco; Marín, Arnaldo

    2011-01-01

    A manipulative caging experiment was carried out to evaluate the role of wild fish and motile epibenthic invertebrates on the benthic system influenced by an open water fish farm. Chemical and biological parameters of the sediment were measured as indicators of the ecological benthic status. The combination of wild fish and currents notably lowered aquaculture waste sedimentation below the fish farm. The limited waste sedimentation rate could have limited the scavenger and predation activity of wild fish on the benthos, whose role may be taken over by motile epibenthic invertebrates. The interaction of these motile epibenthic invertebrates with the sediment differed from that observed with fish. The motile epibenthic invertebrates led to more reduced conditions with lower redox values, significantly decreased the number of species of macrofaunal benthic assemblages and significantly modified macrofaunal benthic assemblages. Therefore, epibenthic invertebrates do not seem to have an ameliorative effect on the benthic status produced by fish farming. Since the effects of epibenthic species on the benthic system can greatly vary according to their identity, further experiments should be performed to better understand the drivers that influence the epibenthic species identity that modulate the benthic system affected by fish farming.

  13. Conservation status of Chinese species: (2) Invertebrates.

    Science.gov (United States)

    Xie, Yan; Wang, Sung

    2007-06-01

    A total of 2441 invertebrate species were evaluated using the IUCN Red List Criteria and Regional Guidelines. Approximately 30 experts were involved in this project, which covered a wide range of species, including jellyfish, corals, planarians, snails, mollusks, bivalves, decapods, benthic crustaceans, arachnids (spiders, scorpions), butterflies, moths, beetles, sea cucumbers, sea urchins, sea stars, acorn worms and lancelets. In general, invertebrate species in China were found to be severely threatened, with 0.9% being critically endangered, 13.44% endangered and 20.63% vulnerable. All species of hermatypic corals and planarians are threatened. More than 80% of evaluated species face serious threat due to habitat destruction by coral collection, logging, non-woody vegetation collection, timber plantations, non-timber plantations, extraction and/or livestock. Other threats are intrinsic factors, harvesting by humans, alien invasive species and pollution. The main intrinsic factors contributing to the high levels of threat are limited dispersal and restricted range. No conservation measures have been taken for 70% of the threatened invertebrates evaluated. Existing conservation measures include: strengthening of national and international legislation (Convention on International Trade in Endangered Species of Wild Fauna and Flora), increasing public awareness, studying population trends/monitoring, and establishment of protected areas. The major conservation measure employed is strengthening of policies. Relative to the situation worldwide (2006 IUCN Red List), there is little information available about invertebrate extinctions in China. PMID:21396022

  14. Tumors in invertebrates

    Directory of Open Access Journals (Sweden)

    F Tascedda

    2014-06-01

    Full Text Available Tumors are ectopic masses of tissue formed by due to an abnormal cell proliferation. In this review tumors of several invertebrate species are examined. The description of tumors in invertebrates may be a difficult task, because the pathologists are usually inexperienced with invertebrate tissues, and the experts in invertebrate biology are not familiar with the description of tumors. As a consequence, the terminology used in defining the tumor type is related to that used in mammalian pathology, which can create misunderstandings in some occasions.

  15. A temporal and spatial study of invertebrate communities associated with hard-bottom habitats in the South Atlantic Bight

    OpenAIRE

    Wenner, E. L.; Hinde, P.; Knott, D. M; Van Dolah, R. F.

    1984-01-01

    Species composition, biomass, density, and diversity of benthic invertebrates from six bard-bottom areas were evaluated. Seasonal collections using a dredge, trawl, and suction and grab samplers yielded 432, 525, and 845 taxa, respectively. Based on collections wltb the different gear types, species composition of invertebrates was found to change bathymetrically. Inner- and mlddle-shelf sites were more similar to each other in terms of invertebrate species composition than they were to outer...

  16. Benthic community structure in the Gorgan Bay (Southeast of the Caspian Sea, Iran: Correlation to water physiochemical factors and heavy metal concentration of sediment

    Directory of Open Access Journals (Sweden)

    Mahmood Saghali

    2013-11-01

    Full Text Available Macrobentos frequency and biomass was investigated in the Gorgan Bay in 2011. Five sampling sites were chosen to collect benthos and sediment from the Bay using a Van Veen grab sampler. Samples were collected seasonally. Macrobenthos were indentified and their biomass was recorded. Sediment heavy metals concentration were measured using Atomic Absorption Spectroscopy. A total of 11 families belonging to three phyla of invertebrates were found. The phyla were Annelids (Nereidae, Naididae, Ampharetidae, Lumbriculidae, Tubificidae and Amphiporidae, Arthropods (Pontogammaridae, Balanidae and Chironomidae and Mollusks (Cardiidae and Scrobicularidae. Lumbriculidae (413 individuals m-2, corresponding to 18.7% and Cardiidae (55.2 g m-2, corresponding to 82.4% had the highest frequency and biomass, respectively. Annelids with an average of 1557 individuals m-2 was the most frequent groups, while, mollusks with the average of 141 g per m2 had the highest biomass. Results showed that macrobenthos frequency in summer was significantly higher than those of the other seasons, however, in the case of biomass, there was a significantly higher biomass in the spring than the other seasons. The maximum metal concentration was related to Zn and Pb, whereas, Cr and Cd had the lowest values. There was no significant difference in Zn and Cr concentrations among the sampling seasons. Pb concentration in winter was significantly lower than the other seasons, whereas, Cd concentrations in the spring and summer were significantly lower than the autumn and winter. There were some correlations between benthos frequency and water physiochemical characteristics and sediment heavy metal levels. This study indicated that benthic fauna of the Gorgan Bay and the Caspian Sea are not similar. Also, results showed that benthic fauna communities are affected by sediment heavy metal concentrations and water physiochemical characteristics, however, different benthos groups show

  17. BENTHIC MACROFAUNA AND HABITAT RELATIONSHIPS IN TILLAMOOK BAY

    Science.gov (United States)

    Tillamook Bay is subject to natural and man-made stressors, such as increased nutrients and sediments, which can alter its habitats and, thereby, impact its productivity and ecological resources. The benthic macrofauna are small, sediment-dwelling invertebrates which have strong...

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

    OpenAIRE

    iana CUPŞA; Magdolna BIRKAS; Ilie TELCEAN

    2009-01-01

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

  19. Benthic community structure and organic matter variation in response to oceanographic events on the Brazilian SE inner shelf

    Science.gov (United States)

    Rodrigues Alves, Betina G.; Ziggiatti Güth, Arthur; Caruso Bícego, Márcia; Airton Gaeta, Salvador; Gomes Sumida, Paulo Yukio

    2014-08-01

    For 13 months, this study monitored the sedimentary organic matter composition, benthic bacteria and macrofauna at a permanent sampling station on the inner shelf (~ 40 m depth) near Ubatuba in SE Brazil. The sedimentary organic matter compounds were evaluated for total organic matter content, lipid biomarkers and phytopigments. The organic matter content varied significantly over time but no clear seasonal trend was evident. Lipid biomarker composition revealed that particulate organic matter was primarily derived from autochthonous sources, such as diatoms, other microalgae, zooplankton, sediment bacteria and benthic metazoan fauna. Phytopigment results revealed that the majority of the organic matter in the sediments was refractory as opposed to labile, suggesting that the labile portion is rapidly consumed. The benthic dynamics off the coast of Ubatuba is highly influenced by the intrusion of the South Atlantic Central Water (SACW) onto the shelf, which brings nutrients up to the euphotic zone and stimulates new phytoplanktonic production. This enhances the flux of organic matter to the bottom and increases benthic biota density, mainly bacteria. These results suggest a strong and complex benthic-pelagic coupling that is influenced by both mesoscale oceanographic events (i.e., intrusion of SACW) and local events (cold fronts) through remobilization of the sediments.

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

    Science.gov (United States)

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

    2013-04-01

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

  1. The interplay between habitat structure and chemical contaminants on biotic responses of benthic organisms.

    Science.gov (United States)

    Mayer-Pinto, Mariana; Matias, Miguel G; Coleman, Ross A

    2016-01-01

    Habitat structure influences the diversity and distribution of organisms, potentially affecting their response to disturbances by either affecting their 'susceptibility' or through the provision of resources that can mitigate impacts of disturbances. Chemical disturbances due to contamination are associated with decreases in diversity and functioning of systems and are also likely to increase due to coastal urbanisation. Understanding how habitat structure interacts with contaminants is essential to predict and therefore manage such effects, minimising their consequences to marine systems. Here, we manipulated two structurally different habitats and exposed them to different types of contaminants. The effects of contamination and habitat structure interacted, affecting species richness. More complex experimental habitats were colonized by a greater diversity of organisms than the less complex habitats. These differences disappeared, however, when habitats were exposed to contaminants, suggesting that contaminants can override effects of habitats structure at small spatial scales. These results provide insight into the complex ways that habitat structure and contamination interact and the need to incorporate evidence of biotic responses from individual disturbances to multiple stressors. Such effects need to be taken into account when designing and planning management and conservation strategies to natural systems. PMID:27168991

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

    NARCIS (Netherlands)

    Verdonschot, P.F.M.

    2008-01-01

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

  3. The Effects of Marenzelleria spp on the Benthic Macro Fauna Community Structure in the Isefjord

    OpenAIRE

    Olsen, Jeppe; Reyhe, Tore; Happel, Elisabeth; Kayikci, Ozan

    2008-01-01

    In environmental biology, the interspecies interactions are always interesting and much studied as these relations may change the destiny and life of individuals and gradually the community structure in the given area. In addition to some regular relationships, such as symbiosis, commensalism, prey - predator and etc. there is also the term “invasive species”. The effect of such invasive species, Marenzellaria spp. is investigated in this survey. Marenzelleria spp. belongs to the Phylum A...

  4. Benthic biofilm structure controls the deposition-resuspension dynamics of fine clay particles

    Science.gov (United States)

    Hunter, W. R.; Roche, K. R.; Drummond, J. D.; Boano, F.; Packman, A. I.; Battin, T. J.

    2015-12-01

    In fluvial ecosystems the alternation of deposition and resuspension of particles represents an important pathway for the downstream translocation of microbes and organic matter. Such particles can originate from algae and microbes, the spontaneous auto-aggregation of organic macromolecules (e.g., "river sown"), terrestrial detritus (traditionally classified as "particulate organic matter"), and erosive mineral and organo-mineral particles. The transport and retention of particles in headwater streams is associated with biofilms, which are surface-attached microbial communities. Whilst biofilm-particle interactions have been studied in bulk, a mechanistic understanding of these processes is lacking. Parallel macroscale/microscale observations are required to unravel the complex feedbacks between biofilm structure, coverage and the dynamics of deposition and resuspension. We used recirculating flume mesocosms to test how changes in biofilm structure affected the deposition and resuspension of clay-sized (Biofilms were grown in replicate 3-m-long recirculating flumes over variable lengths of time (0, 14, 21, 28, and 35) days. Fixed doses of fluorescent clay-sized particles were introduced to each flume and their deposition was traced over 30 minutes. A flood event was then simulated via a step increase in flowrate to quantify particle resuspension. 3D Optical Coherence Tomography was used to determine roughness, areal coverage and height of biofilms in each flume. From these measurements we characterised particle deposition and resuspension rates, using continuous time random walk modelling techniques, which we then tested as responses to changes in biofilm coverage and structure under both base-flow and flood-flow scenarios. Our results suggest that biofilm structural complexity is a primary control upon the retention and downstream transport of fine particles in stream mesocosms.

  5. Spatial and temporal variability in particle-bound pesticide exposure and their effects on benthic community structure in a temporarily open estuary

    Science.gov (United States)

    Bollmohr, S.; van den Brink, P. J.; Wade, P. W.; Day, J. A.; Schulz, R.

    2009-03-01

    Spatial and temporal variations in particle-bound pesticide contamination, natural environmental variables, and benthic abundance were measured during the dry summer season within a temporarily open estuary (Lourens River). This study focused on the effect of particle-associated pesticides on the dynamics of the benthic community (including epi-benthic, hyper-benthic, and demersal organisms) by comparing two runoff events, differing in their change in pesticide concentration and environmental variables. The two chosen sites were situated within the upper and middle reaches of the estuary and differ significantly in salinity ( p = 0.001), flow ( p = 0.5), temperature ( p < 0.001) and particulate organic carbon in the sediment ( p < 0.001). Generally higher particle-bound pesticides were found in the upper reaches. The first runoff event was characterised by an increase in pesticides (chlorpyrifos, endosulfan and cypermethrin) and hardly any change in natural environmental variables, whereas the second runoff event was characterised by no increase in pesticide but a significant change in natural environmental variables like salinity, temperature and flow. The most evident spatial difference in community structure was shown by the use of Principal Response Curve after the first runoff event, whereas no response was shown after the second runoff event. The variables which explained most of the spatial differences are Total Organic Carbon, salinity, chlorpyrifos and endosulfan concentrations. The species contributing most to the spatial differences are the estuarine harpacticoid Mesochra and Canthocamptus (lower abundance at the upper reaches) and the freshwater species Dunhevedia and Thermocyclops (higher abundance within upper reaches). Within the spatial variability (between upper and middle reaches) the authors were able to detect a link between endosulfan, chlorpyrifos exposure, TOC and salinity and community change by comparing the two runoff events.

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

    Science.gov (United States)

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

    2016-06-01

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

  7. Do invertebrates have culture?

    OpenAIRE

    Danchin, Étienne; Blanchet, Simon; Mery, Frédérick; Wagner, Richard H.

    2010-01-01

    A recent paper in Current Biology1 showed for the first time that female invertebrates (Drosophila melanogaster) can perform mate choice copying. Here, we discuss how female mating preferences in this species may be transmitted culturally. If culture occurs in invertebrates, it may be a relatively ancient evolutionary process that may have contributed to the evolution of many different taxa. This would considerably broaden the taxonomic range of cultural processes and suggest the need to incl...

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

    Science.gov (United States)

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

  9. 净水厂生物活性炭池无脊椎动物群落结构研究%Study of the invertebrate community structure in a biological activated carbon filter

    Institute of Scientific and Technical Information of China (English)

    尤为; 王庆; 刘丽君; 杨宇峰

    2012-01-01

    调查了南方某净水厂生物活性炭(BAC)池中无脊椎动物的群落结构周年变化.共发现无脊椎动物26种(属或类).轮虫为优势类群,其次为桡足类及其无节幼体、枝角类、寡毛类.调查期间BAC池炭总管水中无脊椎动物的平均丰度是主臭氧后水的8.2倍,炭滤后水中无脊椎动物的平均丰度是炭滤前水的12~18.7倍.研究结果表明,BAC池是无脊椎动物滋生的重要场所.春夏两季BAC池中无脊椎动物增长较快,水温升高对BAC池中无脊椎动物滋生起促进作用.夏季和其他时期分别以桡足类和轮虫占据优势,存在着小型无脊椎动物(轮虫)向大型无脊椎动物(桡足类)演替的现象.%A study was carried out to investigate the invertebrate community structure changes in the biological activated carbon (BAC) filter of some water treatment plant in South China. Totally 26 kinds of invertebrate were discovered. Rotifers were dominant species, and the others are copepods, nauplii larvae, cladocerans, and oligochaetes in declining sequence. During the research, the average invertebrate abundance in the filter was 8. 2 times of that in post-inter-ozonation-water, and the average invertebrate abundance after filter was 12 to 18. 7 times of that before filter. The research showed that BAC filter was the major spot for invertebrate breeding. During summer and fall, the invertebrate in BAC grow faster than other seasons. The increase of water temperature could improve the invertebrate breeding. In summer and other seasons, the copepods and rotifer were the dominant species respectively, and the succession from small invertebrate (rotifer) to large invertebrate (copepods) also existed.

  10. Aeolian Transport of Invertebrates

    Science.gov (United States)

    Gill, T. E.; Walsh, E. J.; Wallace, R. L.; Rojo, L.; Rivas, J. A.

    2012-12-01

    Playas and other ephemeral desert wetlands are preferential terrestrial landforms for dust emission. These sites also are habitat for a diverse assemblage of minute invertebrates. When wetlands desiccate, these invertebrates survive as resting stages (propagules). Thus, playas serve as isolated, ephemeral, biogeographical islands for aquatic invertebrates, but it is unclear how propagules disperse across distances as far as hundreds of kilometers to colonize hydrologically disconnected basins. Aeolian transport (anemochory) may provide the mechanism, especially since many invertebrate propagules are long-lived, aerodynamically shaped, possess low-density, and their size (30-600 μm) falls within the same texture as aeolian dust and sand grains. We are collecting and culturing wind-transported sediment to document its ability to serve in the dispersal of aridland invertebrate propagules. Deposited aeolian sediment was collected from marble-type traps placed on the roof of the Biological Sciences Building at the University of Texas, El Paso, during 19 individual regional-scale Chihuahuan Desert blowing dust/sand events between April 2010 and May 2012. Known source areas for these dust events include playas and ephemeral streams ~40- 150 km upwind. The mean dry grain size of the deposited sediment for each event ranged from 66 to 141 μm. Clean-water rinses of material from each event or standard rehydrations for culturing invertebrates were monitored microscopically for the appearance of organisms. Invertebrates hatched from the sediment of 13 events. Ciliates were detected in each of those samples: gastrotrichs appeared in three samples, nematodes and bdelloid rotifers in two samples, and clam shrimp in one. We have also rehydrated aeolian sediments, collected in standard dust traps, from many dust-emitting playas in Southwest North America and hatched viable organisms including all those previously mentioned as well as branchiopods, fairy shrimp, copepods

  11. Benthic fauna of extremely acidic lakes (pH 2-3)

    Energy Technology Data Exchange (ETDEWEB)

    Rodrigues, G.G.

    2001-07-01

    The structure of the benthic invertebrate communities were investigated in terms of composition, abundance, and biomass from extremely acidic lakes with pH values from 2 to 3 in areas where coal was intensively mined in the Lusatian region in the eastern region of Germany. Benthic invertebrates colonisation on leaves and the breakdown rate processing of the three deciduous leaf: Betula pendula (birch), Fraxinus excelsior (ash), and Juglans regia (walnut) were investigated. Also, the main key-species of these acidic environments were investigated, in terms of description of pupal exuviae of Chironomus crassimanus and the feeding habit of this acid-resistant species through analysis of their gut content. The benthic food web in extremely acidic mining Lusatian lakes is very short in terms of species richness, trophic relationship, guilds and functional feeding groups. Collector-filters and scraper-grazers were absent in extremely acidic mining lakes (AML 107, AML 111 and AML 117). Shredders as Limnophyes minimus (Diptera, Chironomidae, Orthocladiinae) and Hydrozetes lacustris (Acari, Hydrozetidae) occurred in low abundance in AML 107 and AML 111, and it may be in response to slow leaf breakdown process in these ecosystems, except in AML 117 where the H. lacustris contributed most to ecosystems functioning via the processing of litter. Aquatic insects as Sialis lutaria (Megaloptera, Sialidae), Orectochilus villosus (Coleoptera, Gyrinidae), Coenagrion mercuriale (Odonata, Coenagrionidae), and Phryganeidae (Trichoptera) are the top-predators of these ecosystems. They did not depend on the level of pH in the lakes, but on the availability of food resources. (orig.)

  12. Trait-based modelling of bioaccumulation by freshwater benthic invertebrates.

    Science.gov (United States)

    Sidney, Livia Alvarenga; Diepens, Noël J; Guo, Xiaoying; Koelmans, Albert A

    2016-07-01

    Understanding the role of species traits in chemical exposure is crucial for bioaccumulation and toxicity assessment of chemicals. We measured and modelled bioaccumulation of polychlorinated biphenyls (PCBs) in Chironomus riparius, Hyalella azteca, Lumbriculus variegatus and Sphaerium corneum. We used a battery test procedure with multiple enclosures in one aquarium, which maximized uniformity of exposure for the different species, such that the remaining variability was due mostly to species traits. The relative importance of uptake from either pore water or sediment ingestion was manipulated by using 28 d aged standard OECD sediment with low (1%) and medium (5%) OM content and 13 months aged sediment with medium OM (5%) content. Survival was ≥76% and wet weight increased for all species. Reproduction of H. azteca and weight gain of H. azteca and S. corneum were significantly higher in the medium OM aged sediments than in other sediments, perhaps due to a more developed microbial community (i.e., increase in food resources). Biota-sediment accumulation factors (BSAF) ranged from 3 to 114, depending on species and PCB congener, with C. riparius (3-10)

  13. Structural and functional insights into the ligand-binding domain of a nonduplicated retinoid X nuclear receptor from the invertebrate chordate amphioxus.

    Science.gov (United States)

    Tocchini-Valentini, Giuseppe D; Rochel, Natacha; Escriva, Hector; Germain, Pierre; Peluso-Iltis, Carole; Paris, Mathilde; Sanglier-Cianferani, Sarah; Van Dorsselaer, Alain; Moras, Dino; Laudet, Vincent

    2009-01-16

    Retinoid X nuclear receptors (RXRs), as well as their insect orthologue, ultraspiracle protein (USP), play an important role in the transcription regulation mediated by the nuclear receptors as the common partner of many other nuclear receptors. Phylogenetic and structural studies have shown that the several evolutionary shifts have modified the ligand binding ability of RXRs. To understand the vertebrate-specific character of RXRs, we have studied the RXR ligand-binding domain of the cephalochordate amphioxus (Branchiostoma floridae), an invertebrate chordate that predates the genome duplication that produced the three vertebrates RXRs (alpha, beta, and gamma). Here we report the crystal structure of a novel apotetramer conformation of the AmphiRXR ligand-binding domain, which shows some similarity with the structures of the arthropods RXR/USPs. AmphiRXR adopts an apo antagonist conformation with a peculiar conformation of helix H11 filling the binding pocket. In contrast to the arthropods RXR/USPs, which cannot be activated by any RXR ligands, our functional data show that AmphiRXR, like the vertebrates/mollusk RXRs, is able to bind and be activated by RXR ligands but less efficiently than vertebrate RXRs. Our data suggest that amphioxus RXR is, functionally, an intermediate between arthropods RXR/USPs and vertebrate RXRs. PMID:18986992

  14. 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.

  15. Using invertebrate remains and pigments in the sediment to infer changes in trophic structure after fish introduction in Lake Fogo: a crater lake in the Azores

    DEFF Research Database (Denmark)

    Skov, Tue; Buchaca, T; Amsinck, Susanne Lildal;

    2010-01-01

    Fish introduction may have marked effects on the trophic dynamics and ecological state of former fishless lakes, but due to scarcity of historical data this can seldom be documented. We used remains of cladoceran, chironomid and pigment assemblages in the sediment archive to unravel the effect of...... pelagic dominated ecosystem, as cryptophytes became markedly more abundant at the expense of benthic diatoms. Trout introduction was followed by a return to a more benthic cladoceran and benthic algae (pigments) dominated state, which we attribute to trout predation on carp leading to improved water...

  16. Trawled megafaunal invertebrate assemblages from bathyal depth of the Mid-Atlantic Ridge (48°-54°N)

    Science.gov (United States)

    Alt, Claudia H. S.; Rogacheva, Antonina; Boorman, Benjamin; Alan Hughes, J.; Billett, David S. M.; Gooday, Andrew J.; Jones, Daniel O. B.

    2013-12-01

    We investigated the effects of contrasting surface primary production on the benthic invertebrate megafauna at four sites on the Mid-Atlantic Ridge. The sites, designated NW, NE, SW and SE, were located to the west and east of the Ridge axis and to the north and south of the Charlie-Gibbs Fracture Zone. Benthic megafauna were sampled in 2007 and 2009 with a semi-balloon otter trawl, at a target depth of 2,500 m. The total biomass and density of major taxonomic groups did not differ significantly between sites, despite those to the north being characterised by greater surface productivity than those to the south. However, the density and biomass of individual taxonomic groups, as well as diversity and body size, all showed significant differences between sites. Diversity was highest at the SE, and lowest at the NE site. Most species were larger to the north. Community composition was significantly different between all sites, with the greatest number of unique species found at the SE, and noticeably fewer unique species at the northern sites. There was no clear correlation between the surface productivity and community structure, suggesting complex ecological controls on the communities. It is speculated that, in addition to the energy supply, drivers such as strong currents and sediment characteristics, play an important role in shaping the communities at the different sites. To what extent the ridge acts as a dispersal barrier for benthic invertebrate fauna remains unclear. However, high numbers of species unique to the southern site suggest a limited dispersal between the northern and southern areas.

  17. 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...

  18. Stimulation of microbial nitrogen cycling in aquatic ecosystems by benthic macrofauna: mechanisms and environmental implications

    OpenAIRE

    P. Stief

    2013-01-01

    Invertebrate animals that live at the bottom of aquatic ecosystems (i.e., benthic macrofauna) are important mediators between nutrients in the water column and microbes in the benthos. The presence of benthic macrofauna stimulates microbial nutrient dynamics through different types of animal–microbe interactions, which potentially affect the trophic status of aquatic ecosystems. This review contrasts three types of animal–microbe interactions in the benthos of aquatic ecosystems: (i) e...

  19. Stimulation of microbial nitrogen cycling in aquatic ecosystems by benthic macrofauna: mechanisms and environmental implications

    OpenAIRE

    P. Stief

    2013-01-01

    Invertebrate animals that live at the bottom of aquatic ecosystems (i.e., benthic macrofauna) are important mediators between nutrients in the water column and microbes in the benthos. The presence of benthic macrofauna stimulates microbial nutrient dynamics through different types of animal–microbe interactions, which potentially affect the trophic status of aquatic ecosystems. This review contrasts three types of animal–microbe interactions in the benthos of aquatic ecosys...

  20. Understory vegetation, soil structure and soil invertebrates in Congolese eucalypt plantations, with special reference to the invasive plant Chromolaena odorata and earthworm populations

    OpenAIRE

    Mboukou Kimbatsa, Irène; Bernhard Reversat, France; Loumeto, J.J.; J. Ngao; Lavelle, Patrick

    2007-01-01

    Earthworm relationships with vegetation have received extensive attention, and earthworm density has been shown to be related to vegetation types or plant species. However, the factors involved are rarely known. In Congo, we studied the effect of Chromolaena odorata (L) R.M. King and H. Robinson, which invades eucalypt plantations, on soil invertebrates, especially earthworms. In order to investigate relationships between vegetation cover and soil invertebrates, four understory species, inclu...

  1. Mucosal immunity in invertebrates

    Czech Academy of Sciences Publication Activity Database

    Bilej, Martin

    Vol. 1. Elsevier: Academic Press, 2015 - (Městecký, J.; Strober, W.; Russell, M.; Kelsall, B.; Cheroutre, H.; Lambrecht, B.), s. 135-144. (Fourth Edition). ISBN 978-0-12-415847-4 Institutional support: RVO:61388971 Keywords : mucosal immunity * invertebrates Subject RIV: EC - Immunology

  2. Survey of the marine benthic infauna collected from the United States radioactive waste disposal sites off the Farallon Islands, California. Final report

    International Nuclear Information System (INIS)

    Benthic biological samples were taken in 1977 from the vicinity of the Farallon Islands radioactive waste disposal sites for characterization of the infaunal macroinvertebrates and foraminifera. A total of 120 invertebrate species were collected, of which 75 species (63 percent) were polychaetes. Forty-three of these polychaete species have not previously been reported from depths greater than 1000m. A total of 1044 macroinvertebrate specimens were collected of which 54 percent were polychates. Only the nematods were present at all six benthic stations, but the community structure was dominated by the polychaetes Tauberia gracilis, Allia pulchra, Chaetozone setosa, and Cossura candida. Living and dead foraminifera were reported. The possible role of polychaetes in bioturbation and in the marine food chain is briefly discussed with respect to the various polychaete feeding mechanisms

  3. Benthic ecology of the northeastern Chukchi Sea. Part II. Spatial variation of megafaunal community structure, 2009-2010

    Science.gov (United States)

    Blanchard, Arny L.; Parris, Carrie L.; Knowlton, Ann L.; Wade, Nicole R.

    2013-09-01

    Sources for spatial variability of benthic megafaunal communities in the northeastern Chukchi Sea are poorly documented and may include altered water circulation patterns, as noted for macrofauna. Spatial variability of megafauna was investigated by sampling with a plumb-staff beam trawl in three petroleum leases, the Klondike, Burger, and Statoil study areas, as part of a multi-disciplinary research program in the northeastern Chukchi Sea ecosystem. Trawling occurred during two sampling periods from 2009 and one in 2010 with a total of 81 trawls from 38 stations. A total of 99 discrete taxonomic categories were identified in 2009 and 2010 which were expanded to 239 taxa in the laboratory. Biomass in the three study areas ranged from ∼15,500 to ∼96,000 g 1000 m-2 and numerical density ranged from ∼8500 to ∼134,000 individuals 1000 m-2. Although the megabenthic species-assemblages in all three study areas were similar in composition, average biomass values were higher in Burger (ranging from ∼54,000 to ∼96,000 g 1000 m-2) where altered water circulation occurs, than in Klondike (ranging from ∼15,500 to ∼31,000 g 1000 m-2) or Statoil (∼15,000 g 1000 m-2). The brittle star Ophiura sarsi was the numerically dominant megafauna (70% of total biomass) followed by the snow crab Chionoecetes opilio (7% total biomass), as noted in prior investigations in the region. Biomass and density of benthic megafauna in this region reflected the high quantities of seasonal production reaching the benthos in the shallow waters of the Chukchi Sea. Differences in benthic communities among study areas were associated with variations in bottom-water temperature and latitude, and to a lesser extent, water depth and percent mud. We believe these associations arise from effects of topography on northward-flowing water, that create regions of slower currents, and consequently, higher organic deposition.

  4. Benthic macrofauna variations and community structure in Cenomanian cyclic chalk-marl from Southerham Grey Pit, SE England

    DEFF Research Database (Denmark)

    Lauridsen, Bodil Wesenberg; Gale, A. S.; Surlyk, Finn

    2009-01-01

    . The material comprises washing residues of 24 bulk samples collected from chalk and marl half-cycles. A total of 5055 invertebrate specimens were retrieved and referred to 68 species, forming the basis for the recognition of six guilds. In general, the fauna is more diverse in marl than in chalk, but...... clearly well adapted to both facies and thus to the fine grain size of the substrate rather than to lithology. The systematic difference in diversity between chalk and marl samples was possibly caused by long-term climatic and oceanographic changes and thus could represent a biological response to...

  5. Predicting estuarine benthic production using functional diversity

    Directory of Open Access Journals (Sweden)

    Marina Dolbeth

    2014-05-01

    Full Text Available We considered an estuarine system having naturally low levels of diversity, but attaining considerable high production levels, and being subjected to different sorts of anthropogenic impacts and climate events to investigate the relationship between diversity and secondary production. Functional diversity measures were used to predict benthic production, which is considered as a proxy of the ecosystem provisioning services. To this end, we used a 14-year dataset on benthic invertebrate community production from a seagrass and a sandflat habitat and we adopted a sequential modeling approach, where abiotic, trait community weighted means (CWM and functional diversity indices were tested by generalized linear models (GLM, and their significant variables were then combined to produce a final model. Almost 90% of variance of the benthic production could be predicted by combining the number of locomotion types, the absolute maximum atmospheric temperature (proxy of the heat waves occurrence, the type of habitat and the mean body mass, by order of importance. This result is in agreement with the mass ratio hypothesis, where ecosystem functions/services can be chiefly predicted by the dominant trait in the community, here measured as CWM. The increase of benthic production with the number of locomotion types may be seen as greater possibility of using the resources available in the system. Such greater efficiency would increase production. The other variables were also discussed in line of the previous hypothesis and taking into account the general positive relationship obtained between production and functional diversity indices. Overall, it was concluded that traits representative of wider possibilities of using available resources and higher functional diversity are related with higher benthic production.

  6. 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.

  7. Abundance of non-native crabs in intertidal habitats of New England with natural and artificial structure

    OpenAIRE

    Lovely, Christina M.; O’Connor, Nancy J.; Judge, Michael L.

    2015-01-01

    Marine habitats containing complex physical structure (e.g., crevices) can provide shelter from predation for benthic invertebrates. To examine effects of natural and artificial structure on the abundance of intertidal juvenile crabs, 2 experiments were conducted in Kingston Bay, Massachusetts, USA, from July to September, 2012. In the first experiment, structure was manipulated in a two-factor design that was placed in the high intertidal for 3 one-week periods to test for both substrate typ...

  8. Halogenated indole alkaloids from marine invertebrates.

    Science.gov (United States)

    Pauletti, Patrícia Mendonça; Cintra, Lucas Silva; Braguine, Caio Guedes; da Silva Filho, Ademar Alves; Silva, Márcio Luís Andrade E; Cunha, Wilson Roberto; Januário, Ana Helena

    2010-01-01

    This review discusses the isolation, structural elucidation, and biological activities of halogenated indole alkaloids obtained from marine invertebrates. Meridianins and related compounds (variolins, psammopemmins, and aplicyanins), as well as aplysinopsins and leptoclinidamines, are focused on. A compilation of the (13)C-NMR spectral data of these selected natural indole alkaloids is also provided. PMID:20559487

  9. Halogenated Indole Alkaloids from Marine Invertebrates

    Directory of Open Access Journals (Sweden)

    Ana Helena Januário

    2010-04-01

    Full Text Available This review discusses the isolation, structural elucidation, and biological activities of halogenated indole alkaloids obtained from marine invertebrates. Meridianins and related compounds (variolins, psammopemmins, and aplicyanins, as well as aplysinopsins and leptoclinidamines, are focused on. A compilation of the 13C-NMR spectral data of these selected natural indole alkaloids is also provided.

  10. Halogenated Indole Alkaloids from Marine Invertebrates

    OpenAIRE

    Ana Helena Januário; Wilson Roberto Cunha; Márcio Luís Andrade e Silva; Ademar Alves da Silva Filho; Caio Guedes Braguine; Lucas Silva Cintra; Patrícia Mendonça Pauletti

    2010-01-01

    This review discusses the isolation, structural elucidation, and biological activities of halogenated indole alkaloids obtained from marine invertebrates. Meridianins and related compounds (variolins, psammopemmins, and aplicyanins), as well as aplysinopsins and leptoclinidamines, are focused on. A compilation of the 13C-NMR spectral data of these selected natural indole alkaloids is also provided.

  11. Wetland plant influence on sediment ecosystem structure and trophic function

    OpenAIRE

    Whitcraft, Christine R.

    2007-01-01

    Vascular plants structure wetland ecosystems. To examine mechanisms behind their influence, plants were studied under different scenarios of change: experimental manipulation of cover, invasion, and response to flushing regimes. I tested the hypothesis that wetland plants alter benthic communities through modification of abiotic factors, with cascading effects on microalgae and invertebrate communities. Major plant effects were observed in all systems studied, but the magnitude of, mechanisms...

  12. Major methodological constraints to the assessment of environmental status based on the condition of benthic communities

    Science.gov (United States)

    Medeiros, João Paulo; Pinto, Vanessa; Sá, Erica; Silva, Gilda; Azeda, Carla; Pereira, Tadeu; Quintella, Bernardo; Raposo de Almeida, Pedro; Lino Costa, José; José Costa, Maria; Chainho, Paula

    2014-05-01

    The Marine Strategy Framework Directive (MSFD) was published in 2008 and requires Member States to take the necessary measures to achieve or maintain good environmental status in aquatic ecosystems by the year of 2020. The MSFD indicates 11 qualitative descriptors for environmental status assessment, including seafloor integrity, using the condition of the benthic community as an assessment indicator. Member States will have to define monitoring programs for each of the MSFD descriptors based on those indicators in order to understand which areas are in a Good Environmental Status and what measures need to be implemented to improve the status of areas that fail to achieve that major objective. Coastal and offshore marine waters are not frequently monitored in Portugal and assessment tools have only been developed very recently with the implementation of the Water Framework Directive (WFD). The lack of historical data and knowledge on the constraints of benthic indicators in coastal areas requires the development of specific studies addressing this issue. The major objective of the current study was to develop and test and experimental design to assess impacts of offshore projects. The experimental design consisted on the seasonal and interannual assessment of benthic invertebrate communities in the area of future implementation of the structures (impact) and two potential control areas 2 km from the impact area. Seasonal benthic samples were collected at nine random locations within the impact and control areas in two consecutive years. Metrics included in the Portuguese benthic assessment tool (P-BAT) were calculated since this multimetric tool was proposed for the assessment of the ecological status in Portuguese coastal areas under the WFD. Results indicated a high taxonomic richness in this coastal area and no significant differences were found between impact and control areas, indicating the feasibility of establishing adequate control areas in marine

  13. Benthic processes on and around artificial structures in Swedish coastal waters; Bentiska processer paa och runt artificiella strukturer i Sveriges kustvatten

    Energy Technology Data Exchange (ETDEWEB)

    Malm, Torleif (Stockholms Universitet, Stockholms marina forskningscentrum (Sweden)); Engkvist, Roland (Linneuniversitetet, Institutionen foer Naturvetenskap, Vaexjoe (Sweden))

    2011-03-15

    Within the next few decades, wind farms with an extension of many square kilometres probably will be built in Swedish coastal waters. These installations may affect the ecological communities in various ways, e.g.; by the already known reef-effect, by changing the population structure of key predators such as fish and birds and thereby cause trophic cascades down into the benthic community or by causing changes in the hydrology that may benefit some species, mainly soft bottom species, while others may be disadvantaged. How the wind farms will affect the ecological communities depends probably very much on the initial conditions. During the period 2005-2009 a study was carried out with the aim to investigate the benthic community structure on hard bottoms, before and after larger wind farms have been constructed. The areas explored were Skottarevet in Kattegat, Lillgrund in Oeresund, Utgrunden II in southern Kalmar Strait, Kaarehamn off north-eastern Oeland and Klasaadern off south-western Gotland. For legal and economic reasons, only one farm, Lillgrund was constructed during the project period. Significant differences were found at both species and functional level. The largest divergence was found between the Kattegat and the Baltic Sea with large differences in species composition and in part also with other functional groups. Furthermore, between the Baltic Sea sites, significant differences were also found. The natural communities in the two straits had significantly higher biomass of blue mussels (M. edulis) per square meter compared with the open areas at Gotland and Oeland. In addition,the algal flora differed significantly. Filamentous brown algae favoured by eutrophication dominated the substrate in the straits while the bottoms along the open coastlines were covered with perennial red algae. The wind farm at Lillgrund affected the benthic communities moderately but significant. Mussels and barnacles colonized the surface of the towers and the granite

  14. Impacts of hypoxia on the structure and processes in pelagic communities (zooplankton, macro-invertebrates and fish

    Directory of Open Access Journals (Sweden)

    W. Ekau

    2010-05-01

    Full Text Available Dissolved oxygen (DO concentration in the water column is an environmental parameter that is crucial for the successful development of many pelagic organisms. Hypoxia tolerance and threshold values are species- and stage-specific and can vary enormously. While some fish species may suffer from oxygen values of less than 3 mL O2 L−1 through impacted growth, development and behaviour, other organisms such as euphausiids may survive DO levels as low as 0.1 mL O2 L−1. A change in the average or the range of DO may have significant impacts on the survival of certain species and hence on the species composition in the ecosystem with consequent changes in trophic pathways and productivity.

    Evidence for the deleterious effects of oxygen depletion on pelagic species is scarce, particularly in terms of the effect of low oxygen on development, recruitment and patterns of migration and distribution. While planktonic organisms have to cope with variable DOs and exploit adaptive mechanisms, nektonic species may avoid areas of unfavourable DO and develop adapted migration strategies. Planktonic organisms may only be able to escape vertically, above or beneath the Oxygen Minimum Zone (OMZ. In shallow areas only the surface layer can serve as a refuge, but in deep waters many organisms have developed vertical migration strategies to use, pass through and cope with the OMZ.

    This paper elucidates the role of DO for different taxa in the pelagic realm and the consequences of low oxygen for foodweb structure and system productivity. We describe processes in two contrasting systems, the semi-enclosed Baltic Sea and the coastal upwelling system of the Benguela Current to demonstrate the consequences of increasing hypoxia on ecosystem functioning and services.

  15. Impacts of hypoxia on the structure and processes in the pelagic community (zooplankton, macro-invertebrates and fish

    Directory of Open Access Journals (Sweden)

    W. Ekau

    2009-05-01

    Full Text Available Dissolved oxygen (DO concentration in the water column is an environmental parameter that is crucial for the successful development of many pelagic organisms. Hypoxia tolerance and threshold values are species- and stage-specific and can vary enormously. While some fish species may suffer from oxygen values of less than 3 ml L−1 and show impact on growth, development and behaviour, other organisms such as euphausiids may survive DO levels as low as 0.1 ml L−1. A change in the average or the minimum or maximum DO in an area may have significant impacts on the survival of certain species and hence on the species composition in the ecosystem with consequent changes in trophic pathways and productivity.

    Evidence of the deleterious effects of oxygen depletion on species of the pelagic realm is scarce, particularly in terms of the effect of low oxygen on development, recruitment and patterns of migration and distribution. While planktonic organisms have to cope with different DOs and find adaptive mechanisms, nektonic species may avoid areas of inconvenient DO and develop adapted migrational strategies. Planktonic organisms may only be able to escape vertically, above or beneath the Oxygen Minimum Zone (OMZ. In shallow areas only the surface layer can serve as a refuge, in deep waters many organisms have developed vertical migration strategies to use, pass and cope with the OMZ.

    This paper elucidates the role of DO for different taxa in the pelagic realm and the consequences of low oxygen for foodweb structure and system productivity.

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

    Czech Academy of Sciences Publication Activity Database

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

    2003-01-01

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

  17. Invertebrate welfare: an overlooked issue

    OpenAIRE

    Kelsey Horvath; Dario Angeletti; Giuseppe Nascetti; Claudio Carere

    2013-01-01

    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...

  18. Invertebrate communities of Lake Nabisojjo

    OpenAIRE

    Ndawula, L.M.; Kiggundu, V.; Pabire Ghandi, W.

    2000-01-01

    Invertebrates are organisms without a backbone on the basis of body size. Aquatic invertebrates can be divided into two broad categories: micro-and macro-invertebrates. The former commonly known as zooplankton, ranging in size from < 100um 10 ca.1500um and are mainly planktonic (i.e living suspended in the water column). The latter, also known as benthos, (bottom dwelling) are associated with bottom sediments(ie, living on sediment surface or burrowing in sediments), are much bigger organism ...

  19. Invertebrates in stormwater wet detention ponds - Sediment accumulation and bioaccumulation of heavy metals have no effect on biodiversity and community structure.

    Science.gov (United States)

    Stephansen, Diana Agnete; Nielsen, Asbjørn Haaning; Hvitved-Jacobsen, Thorkild; Pedersen, Morten Lauge; Vollertsen, Jes

    2016-10-01

    The invertebrate diversity in nine stormwater wet detention ponds (SWDP) was compared with the diversity in eleven small shallow lakes in the western part of Denmark. The SWDPs and lakes were chosen to reflect as large a gradient of pollutant loads and urbanization as possible. The invertebrates as well as the bottom sediments of the ponds and shallow lakes were analyzed for copper, iron, zinc, cadmium, chromium, lead, aluminum, nickel, arsenic and the potentially limiting nutrient, phosphorus. The Principal Component Analysis showed that invertebrates in SWDPs and lakes differed with respect to bioaccumulation of these elements, as did the sediments, albeit to a lesser degree. However, the Detrended Correspondence Analysis and the TWINSPAN showed that the invertebrate populations of the ponds and lakes could not be distinguished, with the possible exception of highway ponds presenting a distinct sub-group of wet detention ponds. The SWDPs and shallow lakes studied seemed to constitute aquatic ecosystems of similar taxon richness and composition as did the 11 small and shallow lakes. This indicates that SWDPs, originally constructed for treatment and flood protection purposes, become aquatic environments which play a local role for biodiversity similar to that of natural small and shallow lakes. PMID:27302374

  20. 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.

  1. Benthic Collector and Grazer Communities Are Threatened by Hemlock Woolly Adelgid-Induced Eastern Hemlock Loss

    Directory of Open Access Journals (Sweden)

    Joshua K. Adkins

    2015-08-01

    Full Text Available Eastern hemlock (Tsuga canadensis (L. is a foundation species in eastern North America where it is under threat from the highly invasive, exotic hemlock woolly adelgid (Adelges tsugae. Eastern hemlock is especially important in riparian areas of Central and Southern Appalachia, so we compared the spatial and temporal composition of benthic collector-gatherers, collector-filterers, and grazers in headwater streams with hemlock-dominated riparian vegetation to those with deciduous tree-dominated riparian vegetation to evaluate the extent to which adelgid-induced hemlock loss could influence composition and abundance of these two functional feeding groups. We found differences in benthic invertebrate abundance and family-level diversity based on riparian vegetation and sampling approach, and, often, riparian vegetation significantly interacted with location or season. Collector-gatherers and grazers were more abundant in eastern hemlock streams in the summer, when hemlock litter is readily available and deciduous litter is relatively sparse. Riparian eastern hemlock appears to exert considerable influence on benthic invertebrate functional feeding group composition in headwater stream communities, as expected with a foundation species. With the loss of eastern hemlock due to adelgid-induced mortality, we should expect to see alterations in spatial and temporal patterns of benthic invertebrate abundance and diversity, with potential consequences to both benthic and terrestrial ecosystem function.

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

    Science.gov (United States)

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

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

  3. Benthic aquatic ecosystems across the Permian-Triassic transition: record from biogenic structures in fluvial sandstones, central Transantarctic Mountains

    Science.gov (United States)

    Miller, M. F.

    2000-07-01

    The effect of the Permian extinction in communities inhabiting sandy stream bottoms can be evaluated using trace fossils as proxies for body fossils. Permian and Triassic sandstones exposed in the Beardmore and Shackleton Glacier areas (central Transantarctic Mountains) were deposited in sandy braided streams and contain four types of trace fossils (vertical shafts and horizontal, bilobed and chevron traces). These traces were produced by a single type of animal that moved in the top 30 cm of sediment and dominated the benthic community. Evidence for a single producer includes similar size (diameter) of all traces and change within single specimens from one trace type to another. The animal was not affected by the Permian extinction event, as evidenced by its equal abundance within the Permian (Buckley Formation) and Triassic (Fremouw Formation) fluvial sandstones in the Beardmore Glacier area. Based on trace morphology and on domination of modern sandy river ecosystems by insects, the producer most likely was an insect, although its more precise identity is problematic. Although families of insects with modern aquatic burrowers are not known before the Jurassic, these trace fossils may show that these burrowers were present earlier than the insect body-fossil record suggests. Alternatively, archaic insect groups, many of which became extinct at the end-Permian and are known to have been aquatic but not infaunal, may have included some active burrowers that were unscathed by the Permian extinction.

  4. Phosphorus flux by macrobenthic invertebrates in a shallow eutrophic lake Donghu: spatial change

    Directory of Open Access Journals (Sweden)

    Ji L.

    2011-11-01

    Full Text Available We estimated phosphorus flux mediated by benthic invertebrates from the sediments to the water in a shallow eutrophic lake (lake Donghu, central China and quantified spatial (littoral and central sites and specific (among different benthic taxa differences. The mass-specific excretion rates of phosphorus (soluble reactive phosphorus (SRP, ηmol·mg dry mass–1·h–1 by benthic invertebrates (abundant taxa were estimated experimentally and calculated as a final minus of initial nutrient mass divided by dry mass of organisms. Results showed high importance of chironomid larvae as a contributor to the total P flux from sediments to water in shallow lake Donghu. Benthic biomass (from 0.002 to 32.8 g dry mass·m–2 distribution and species composition (31 taxa were studied (October 2009 in three regions of lake Donghu (Guozhenghu, Miaohu, Yujiahu using samples from three depths: the shallow littoral site (0.2–1 m depth, central site with 2 m depth, and central site with more than 3 m depth. The total estimated SRP excretion by benthic invertebrate reaches 36% of the direct SPR flux from sediments to water in this lake. The phosphorus regeneration by benthic animals is the most intensive in the shallow littoral sites (69.5 µmol P·m–2·day–1 and at least 20 times greater than in central sites (3.4 µmol P·m–2·day–1 of lake Donghu. The results support notable differences in the SRP excretion rates between taxa and sites. The spatial difference in the SRP flux might be considered as a general feature of lakes with periodical changing oxygen near bottom.

  5. 转Bt基因棉对土壤无脊椎动物群落结构的影响%Effect of transgenic Bt cotton on soil invertebrate community structure

    Institute of Scientific and Technical Information of China (English)

    郭建英; 万方浩; 吴岷

    2009-01-01

    Soil invertebrates were collected by Tullgren and Baermann funnels and analyzed using community ecology method. Then soil invertebrate community structures in the 0~15 cm soil layer in transgenic Bt cotton (cvs. "GK12" and "NuCOTN 33B") fields were compared with those in non-Bt cotton (cv. "SM3") fields. Nematodes and acarids are dominant soil invertebrate groups with frequencies above 54% and over 18% respectively in each cotton cultivar field. Compared with parental non-Bt cv. "SM3"field, "GK12" field has more enchytraelidae and less homopetera, psocoptera and diptera. Cumulative numbers of most soil invertebrate groups do not significantly differ in "GK12" and "NuCOTN33B" fields, except that there are less homoptera and more araneae in "GK12" field. Soil invertebrate group richness, Shannon diversity and Pielou evenness are significantly lower in "GK12" field than in "SM3" field. Those in "NuCOTN 33B" field are also higher than in "GK12" field. Scalable one-parametric Renyi-diversity profiles also indicate significantly lower diversity in "GK12" than in "SM3" field, and generally lower diversity in "GK12" than in "NuCOTN 33B" field, except for dominant and common invertebrate groups in the 10~15 cm soil layer. The dynamics of soil invertebrate abundance, diversity and evenness have a similar fluctuation trend for the three cotton cultivar fields. Abundance of soil invertebrate reaches its peak in October during the period from July to November. At the peak, soil invertebrates are concentrated in the 0~5 cm and 10~15 cm soil layers in "SM3" field, but in the 10~15 cm soil layer in "GK12" and "NuCOTN 33B" fields. While invertebrate diversity and evenness decrease in November in "SM3" field, they increase in "GK12" field. The above findings imply that planting "GK12" changes the abundance, and decreases the richness, diversity and evenness of soil invertebrate groups. Soil invertebrate community structures also differ between the two Bt cotton cultivars

  6. Invertebrate colonization rates in the tailwater of a Kentucky flood-control reservoir

    Science.gov (United States)

    Swink, W.D.; Novotny, J.F.

    1985-01-01

    Invertebrate colonization on newly introduced rock substrates was examined from July through October 1982 in the tailwater of Barren River Lake, Kentucky. Chironomidae, the dominant taxon of benthic insects, reached full colonization by day 14. Colonization by Oligochaeta, the other major invertebrate taxon, was not completed by the end of the 95-day period of observation. It may have been delayed because insufficient food (periphyton and detritus) had accumulated on the clean rocks. Rapid recolonization of dewatered substrates may be especially critical for maintaining adequate fish food in tailwaters of flood-control reservoir.

  7. Linking benthic community structure to terrestrial runoff and upwelling in the coral reefs of northeastern Hainan Island

    Science.gov (United States)

    Li, Xiubao; Wang, Daoru; Huang, Hui; Zhang, Jing; Lian, Jiansheng; Yuan, Xiangcheng; Yang, Jianhui; Zhang, Guoseng

    2015-04-01

    Near-shore coral reefs in northeastern Hainan Island are close to river mouths and aquaculture ponds, and also located at the center of the Qiongdong Upwelling (QDU). However, it is still unclear how terrestrial runoff and upwelling influence the community composition and spatial distribution of the benthos. During three cruises in 2010 and 2011 in Wenchang, northeastern Hainan Island, we determined a subset of environmental parameters in seawater (e.g. temperature, salinity, DO, dissolved inorganic nutrient (DIN), turbidity and transparency) and macroalgal δ15N and investigated the benthic communities (e.g. live coral cover, coral species richness, juvenile coral density, macroalgal cover and coverage of calcified algae) by video transect and visual census techniques at 10 stations (i.e. 1S-6D). The results showed that the QDU has influenced the reef waters in Wenchang. In 2011, the upwelling started in early May, peaked in July and disappeared in September and most upwelling events lasted for 1-2 weeks between May and July. The results also demonstrated that the reef water was nutrient enriched. Stations close to the river mouth and aquaculture ponds had higher levels of DIN and a higher percentage of ammonia in DIN, and there was consistently lower live coral cover, juvenile coral density and higher macroalgal cover. At some stations in this study, live coral cover was negatively correlated with macroalgal cover (i.e. 2S-6D). Live coral cover, species richness, and juvenile coral density all increased with the distance away from the river outlet and decreased with the rise of DIN. These results suggest that terrestrial runoff and upwelling stimulate nutrient enrichment, and that overgrowing macroalgae has an important influence on the coral communities in northeastern Hainan Island.

  8. 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

  9. Influence of thermal pollution on parasitocenoses structure in water reservoirs. [Incidence of cestodes and trematodes in fish, amphibians, birds, and invertebrates

    Energy Technology Data Exchange (ETDEWEB)

    Pojmanska, T.

    1976-01-01

    Four species of fish, as well as invertebrates, amphibians, and birds, were collected from five lakes forming the cooling system of two electric power plants. Helminth parasites were collected from these animals. The numbers of some species of cestodes and trematodes were distinctly greater in heated lakes, while the numbers of other species were distinctly lower. The significance of direct and indirect effects of temperature on parasites is discussed. (HLW)

  10. Change in the Terrestrial Invertebrate Community Structure in Relation to Large Fires at the Kutai National Park, East Kalimantan (Borneo), Indonesia

    OpenAIRE

    YAJIMA, Takaaki; ヤジマ, タカアキ; 矢島, 孝昭

    1988-01-01

    1. To know the change and recovery of terrestrial invertebrate community in the tropical rain forest after large fires, the research was done at the Kutai National Park in East Kalimantan (Borneo), Indonesia, in July to August 1986. 2. After consideration of the influence of large fires and the human impact on nature, eleven stations were selected from the unburnt natural forests, unburnt secondary forest, burnt natural forest, burnt secondary forest, and open fileds of Melastoma shr...

  11. Benthic communities on hard substrates covered by Limnoperna fortunei Dunker (Bivalvia, Mytilidae at an estuarine beach (Río de la Plata, Argentina

    Directory of Open Access Journals (Sweden)

    Fernando G. Spaccesi

    2012-01-01

    Full Text Available The structure and composition of benthic communities on hard substrates covered by the nonindigenous bivalve Limnoperna fortunei Dunker, the golden mussel, were quantified in the middle zone of the Río de la Plata Estuary (Argentina from April 2001 through March 2002. A total of 26 taxa were recorded. L. fortunei and Nematoda were the central and dominant groups, with a prodigious abundance of over 80%. The prevalence of L. fortunei, rather than the environmental variables, regulated the dynamics of the associated invertebrate fauna. The golden mussel alters both the structure and function of benthic native communities on hard substrates, allows a higher surface available for colonization and refuge, and provides food source to deposit-feeding organisms in the form of organic or residual material. The mussel also increases the abundance and diversity of taxa on hard substrata - such as Oligochaeta, Hirudinea, Tardigrada, Chironomidae, Copepoda, Tanaidacea, and Hydrachnidia. Similarities and nonparametric multidimensional-scaling analyses indicated that the benthic composition had a seasonal variation. L. fortunei has an environmental impact, an ability to invade new freshwater ambiences worldwide and ecological characteristic comparable to those of Dreissena polymorpha Pallas (the zebra mussel of North America and Europe.

  12. Anti-inflammatory activity in selected Antarctic benthic organisms

    Directory of Open Access Journals (Sweden)

    Juan eMoles

    2014-07-01

    Full Text Available Antarctic benthos was prospected in search for anti-inflammatory activity in polar benthic invertebrates, in two different geographical areas: deep-bottoms of the Eastern Weddell Sea and shallow-waters of the South Shetland Islands. A total of 36 benthic algae and invertebrate species were selected to perform solubility tests in order to test them for anti-inflammatory activity. From these, ethanol extracts of ten species from five different phyla resulted suitable to be studied in cell macrophage cultures (RAW 264.7. Cytotoxicity (MTT method and production of inflammatory mediators (prostaglandin E2, leukotriene B4, interleukin-1 were determined at three extract concentrations (50, 125, 250 g/mL. Bioassays resulted in four different species showing anti-inflammatory activity corresponding to three sponges: Mycale (Oxymycale acerata, Isodictya erinacea, and I. toxophila; and one hemichordate: Cephalodiscus sp. These results show that Antarctic sessile invertebrates may have great value as a source of lead compounds with potential pharmaceutical applications.

  13. Aging and immunosenescence in invertebrates

    Directory of Open Access Journals (Sweden)

    D Stanley

    2012-06-01

    Full Text Available Most contemporary research into aging is driven by interest in the human aging process and in interventions that attenuate the normal and pathophysiological effects of aging, or senescence. Operationally, senescence is the progressive, inevitable breakdown of the organism. Among the changes associated with senescence is the diminished capacity of the immune systems and reactions to challenge, known as immunosenescence. Senescence and age-related immunosenescence has been recorded in several invertebrates, including insects. Two invertebrates, the worm, Caenorhabditis elegans, and the fruit fly, Drosophila melanogaster, are model organisms for research into mechanisms of senescence and of prolonged life spans. In this essay, I will treat some of the available information on immunosenescence in invertebrates. The purpose is to move away from trying to understand human senescence and toward generating new ideas around the application of research into invertebrate immunosenescence to contemporary and emerging problems in aquatic and terrestrial agriculture. I cover mechanisms of senescence, beginning with the original idea of increasing oxidative damage and moving to more recent views. I provide a thumb-nail sketch of insect immunity as a model for the generality of complex invertebrates, then discuss selected examples of immunosenescence in invertebrates. In some instances, changes that look like immunosenescence may be physiological resource trade-offs and I highlight a few examples. Finally, I complete the essay with a few remarks on the potential practical significance of research to understand immunosenescence in invertebrates.

  14. Assessment of Missouri River floodplain invertebrates during historic inundation: implications for river restoration

    OpenAIRE

    Gosch N.J.C.; Miller M.L.; Dzialowski A.R.; Morris D.M.; Gemeinhardt T.R.; Bonneau J.L.

    2014-01-01

    Floodplain connectivity is important to aquatic organisms in large rivers. Anthropogenic alterations regulating the Missouri River have limited connectivity and negatively affected native fauna. Determining the biological response to rare inundation events may be important when considering potential restoration options on a regulated river; thus, we assessed benthic invertebrate and zooplankton communities at three floodplain sites during a historic Missouri River high-water event. Chironomid...

  15. Patterns and Variation in Benthic Biodiversity in a Large Marine Ecosystem.

    Directory of Open Access Journals (Sweden)

    Susan E Piacenza

    Full Text Available While there is a persistent inverse relationship between latitude and species diversity across many taxa and ecosystems, deviations from this norm offer an opportunity to understand the conditions that contribute to large-scale diversity patterns. Marine systems, in particular, provide such an opportunity, as marine diversity does not always follow a strict latitudinal gradient, perhaps because several hypothesized drivers of the latitudinal diversity gradient are uncorrelated in marine systems. We used a large scale public monitoring dataset collected over an eight year period to examine benthic marine faunal biodiversity patterns for the continental shelf (55-183 m depth and slope habitats (184-1280 m depth off the US West Coast (47°20'N-32°40'N. We specifically asked whether marine biodiversity followed a strict latitudinal gradient, and if these latitudinal patterns varied across depth, in different benthic substrates, and over ecological time scales. Further, we subdivided our study area into three smaller regions to test whether coast-wide patterns of biodiversity held at regional scales, where local oceanographic processes tend to influence community structure and function. Overall, we found complex patterns of biodiversity on both the coast-wide and regional scales that differed by taxonomic group. Importantly, marine biodiversity was not always highest at low latitudes. We found that latitude, depth, substrate, and year were all important descriptors of fish and invertebrate diversity. Invertebrate richness and taxonomic diversity were highest at high latitudes and in deeper waters. Fish richness also increased with latitude, but exhibited a hump-shaped relationship with depth, increasing with depth up to the continental shelf break, ~200 m depth, and then decreasing in deeper waters. We found relationships between fish taxonomic and functional diversity and latitude, depth, substrate, and time at the regional scale, but not at the

  16. Assessment of Missouri River floodplain invertebrates during historic inundation: implications for river restoration

    Directory of Open Access Journals (Sweden)

    Gosch N.J.C.

    2014-01-01

    Full Text Available Floodplain connectivity is important to aquatic organisms in large rivers. Anthropogenic alterations regulating the Missouri River have limited connectivity and negatively affected native fauna. Determining the biological response to rare inundation events may be important when considering potential restoration options on a regulated river; thus, we assessed benthic invertebrate and zooplankton communities at three floodplain sites during a historic Missouri River high-water event. Chironomid larvae dominated during most sampling trips and densities were often highest during initial sampling trips with lower densities as high water persisted. Similar trends were evident for rotifer, cladoceran, and copepod densities. Nonmetric multidimensional scaling also showed relatively high dissimilarity of densities between early and late sampling trips for benthic invertebrate and zooplankton communities. As such, short-term inundation may be more beneficial to Missouri River benthic invertebrate (mainly chironomid larvae and zooplankton production than more prolonged inundation lasting a month or more. Furthermore, restoration projects may be designed at elevations allowing more short-term inundation, which would likely benefit native fishes with additional spawning, nursery, and foraging habitat. Levee setbacks may be an effective restoration option for increasing the amount of habitat available for short-term inundation while potentially providing socioeconomic, flood-risk reduction benefits by enhancing flow conveyance.

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

    Science.gov (United States)

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

    2016-02-01

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

  18. 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...

  19. 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...

  20. Maryland 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 coastal invertebrate species in Maryland. Vector polygons in this data set...

  1. 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...

  2. 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...

  3. Biodiversity in Benthic Ecology

    DEFF Research Database (Denmark)

    Friberg, Nikolai; Carl, J. D.

    Foreword: This proceeding is based on a set of papers presented at the second Nordic Benthological Meeting held in Silkeborg, November 13-14, 1997. The main theme of the meeting was biodiversity in benthic ecology and the majority of contributions touch on this subject. In addition, the proceeding...

  4. 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

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

    International Nuclear Information System (INIS)

    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

  6. Assessment of sediment metal contamination in the Mar Menor coastal lagoon (SE Spain: Metal distribution, toxicity, bioaccumulation and benthic community structure

    Directory of Open Access Journals (Sweden)

    2005-01-01

    Full Text Available The Mar Menor coastal lagoon is one of the largest of the Mediterranean Sea. Ancient mining activities in the mountains near its southern basin have resulted in metal contamination in the sediment. The metal bioavailability of these sediments was determined through laboratory toxicity bioassays using three Mediterranean sea urchin species and two amphipod species, and by means of field bioaccumulation measurements involving the seagrass Cymodocea nodosa. The effect of sediment metal contamination on benthic communities was assessed through benthic infaunal analyses, applying classical descriptive parameters and multivariate techniques. The sediments affected by the mining activities presented high levels of toxicity and metals were also accumulated in the seagrass tissues, pointing to metal bioavailability. Although the classical benthic indices were not clear indicators of disturbance, the multivariate techniques applied provided more consistent conclusions.

  7. Bridging levels of pharmaceuticals in river water with biological community structure in the Llobregat River basin (northeast Spain).

    Science.gov (United States)

    Muñoz, Isabel; López-Doval, Julio C; Ricart, Marta; Villagrasa, Marta; Brix, Rikke; Geiszinger, Anita; Ginebreda, Antoni; Guasch, Helena; de Alda, M José López; Romaní, Anna M; Sabater, Sergi; Barceló, Damià

    2009-12-01

    A wide range of human pharmaceuticals are present at low concentrations in freshwater systems, particularly in sections of polluted river. These compounds show high biological activity, often associated with a high stability. These characteristics imply a potential impact of these substances on aquatic biota even when present at low environmental concentrations. Low flow conditions in Mediterranean rivers, most of which flow through densely populated areas and are subjected to intensive water use, increase the environmental risk of these emergent compounds. Here, we studied whether pharmaceuticals in river water affect the local benthic community structure (diatoms and invertebrates). For this purpose, we analyzed the occurrence of pharmaceuticals along the Llobregat River and examined the benthic community structure (diatoms and invertebrates) of this system. Some pharmaceutical products in the Llobregat River registered concentrations greater than those cited in the literature. Multivariate analyses revealed a potential causal association between the concentrations of some anti-inflammatories and beta-blockers and the abundance and biomass of several benthic invertebrates (Chironomus spp. and Tubifex tubifex). Further interpretation in terms of cause-and-effect relationships is discussed; however, it must be always taken with caution because other pollutants also may have significant contributions. Combined with further community experiments in the laboratory, our approach could be a desirable way to proceed in future risk management decisions. PMID:19908929

  8. Crystal structure of the hemolytic lectin CEL-III isolated from the marine invertebrate Cucumaria echinata: implications of domain structure for its membrane pore-formation mechanism.

    Science.gov (United States)

    Uchida, Tatsuya; Yamasaki, Takayuki; Eto, Seiichiro; Sugawara, Hajime; Kurisu, Genji; Nakagawa, Atsushi; Kusunoki, Masami; Hatakeyama, Tomomitsu

    2004-08-27

    CEL-III is a Ca(2+)-dependent and galactose-specific lectin purified from the sea cucumber, Cucumaria echinata, which exhibits hemolytic and hemagglutinating activities. Six molecules of CEL-III are assumed to oligomerize to form an ion-permeable pore in the cell membrane. We have determined the crystal structure of CELIII by using single isomorphous replacement aided by anomalous scattering in lead at 1.7 A resolution. CEL-III consists of three distinct domains as follows: the N-terminal two carbohydrate-binding domains (1 and 2), which adopt beta-trefoil folds such as the B-chain of ricin and are members of the (QXW)(3) motif family; and domain 3, which is a novel fold composed of two alpha-helices and one beta-sandwich. CEL-III is the first Ca(2+)-dependent lectin structure with two beta-trefoil folds. Despite sharing the structure of the B-chain of ricin, CEL-III binds five Ca(2+) ions at five of the six subdomains in both domains 1 and 2. Considering the relatively high similarity among the five subdomains, they are putative binding sites for galactose-related carbohydrates, although it remains to be elucidated whether bound Ca(2+) is directly involved in interaction with carbohydrates. The paucity of hydrophobic interactions in the interfaces between the domains and biochemical data suggest that these domains rearrange upon carbohydrate binding in the erythrocyte membrane. This conformational change may be responsible for oligomerization of CEL-III molecules and hemolysis in the erythrocyte membranes. PMID:15194688

  9. Diversity of litter invertebrates communities from the tunel’na gully in Dnipropetrovsk city

    OpenAIRE

    V. V. Brygadyrenko; L. I. Faly; K. G. Yakimets

    2012-01-01

    Species community of invertebrates in 10 antropogenically transformed ecosystems on the territory of Tunel’na gully (south-west part of Dnipropetrovsk, Ukraine) is investigated. The plant cover of sample areas is shortly described. Taxonomic and ecomorphical structure, indices of biological diversity of litter invertebrate communities are analysed. The invertebrate species inhabited the Tunel’na gully and listed in the Red Data Book of Ukraine and Dnepropetrovsk province are described. The va...

  10. Toxicity Testing of Silver Nanoparticles in Artificial and Natural Sediments Using the Benthic Organism Lumbriculus variegatus

    DEFF Research Database (Denmark)

    Rajala, Juho Elias; Mäenpää, Kimmo; Vehniäinen, Eeva-Riikka;

    2016-01-01

    The increased use of silver nanoparticles (AgNP) in industrial and consumer products worldwide has resulted in their release to aquatic environments. Previous studies have mainly focused on the effects of AgNP on pelagic species, whereas few studies have assessed the risks to benthic invertebrates...... despite the fact that the sediments act as a large potential sink for NPs. In this study, the toxicity of sediment-associated AgNP was evaluated using the standard sediment toxicity test for chemicals provided by the Organization of Economic Cooperation and Development. The freshwater benthic oligochaete...

  11. Arsenic Speciation of Terrestrial Invertebrates

    Energy Technology Data Exchange (ETDEWEB)

    Moriarty, M.M.; Koch, I.; Gordon, R.A.; Reimer, K.J. ((Simon)); ((Royal))

    2009-07-01

    The distribution and chemical form (speciation) of arsenic in terrestrial food chains determines both the amount of arsenic available to higher organisms, and the toxicity of this metalloid in affected ecosystems. Invertebrates are part of complex terrestrial food webs. This paper provides arsenic concentrations and arsenic speciation profiles for eight orders of terrestrial invertebrates collected at three historical gold mine sites and one background site in Nova Scotia, Canada. Total arsenic concentrations, determined by inductively coupled plasma mass spectrometry (ICP-MS), were dependent upon the classification of invertebrate. Arsenic species were determined by high-performance liquid chromatography (HPLC) ICP-MS and X-ray absorption spectroscopy (XAS). Invertebrates were found by HPLC ICP-MS to contain predominantly arsenite and arsenate in methanol/water extracts, while XAS revealed that most arsenic is bound to sulfur in vivo. Examination of the spatial distribution of arsenic within an ant tissue highlighted the differences between exogenous and endogenous arsenic, as well as the extent to which arsenic is transformed upon ingestion. Similar arsenic speciation patterns for invertebrate groups were observed across sites. Trace amounts of arsenobetaine and arsenocholine were identified in slugs, ants, and spiders.

  12. Interactions Between Hydropeaking and Thermopeaking Waves and Their Effect on the Benthic Community in Flume Simulations

    Science.gov (United States)

    Bruno, M.; Carolli, M.; Maiolini, B.; Siviglia, A.; Zolezzi, G.

    2013-12-01

    M. C. Bruno1*, M. Carolli2, B. Maiolini1, A. Siviglia2, Zolezzi, G.2 1 Fondazione Edmund Mach, Research and Innovation Centre. S. Michele all'Adige, I-38010, Italy 2 Department of Civil, Environmental and Mechanical Engineering, University of Trento, I-38100, Trento, Italy * cristina.bruno@fmach.it In Alpine regions, hydroelectricity generation is a key power source and its ability to quickly respond to short-term changes in energy demand makes it an ideal source to meet the needs of the deregulated energy market. This economic need is reflected in the temporal patterns of dam operations with consequences for the water bodies that receive downstream releases in the form of ';hydropeaking', typically consisting of sharp water releases in river reaches below dams. The unsteadiness related to this highly intermittent phenomenon has cascading effects on both biotic and abiotic river resources. Regulation by dams may also significantly affect the thermal regime of riversespecially in mountain areas, where releases from high-elevation reservoirs are often characterized by a markedly different temperature from that of the receiving body, thus causing also sharp water temperature variations, named ';thermopeaking'. While interacting with external forcing, the hydrodynamic and thermal waves propagate downstream with different celerities and a first phase of mutual overlap is followed by a second phase in which the two waves proceed separately. The asynchronous propagation of the two waves produces two distinct but consecutive impacts on the benthic community. Because it is difficult to disentangle the multiple effects of hydropeaking and thermopeaking on benthic macroinvertebrates in experiments conducted in natural conditions, we conducted our studies in an experimental structure of five steel channels directly fed by an alpine stream, the Fersina, a tributary to the Adige River of northern Italy. We simulated two sets of cold and warm thermopeaking waves, and measured the

  13. Carbon flow and trophic structure of an Antarctic coastal benthic community as determined by δ 13C and δ 15N

    Science.gov (United States)

    Gillies, C. L.; Stark, J. S.; Johnstone, G. J.; Smith, S. D. A.

    2012-01-01

    Stable isotopes of carbon and nitrogen were used to determine the different carbon pathways and trophic assemblages amongst coastal benthic fauna of the Windmill Islands, East Antarctica. Macroalgae, pelagic POM, sediment POM and sea ice POM had well-separated δ 13C signatures, which ranged from -36.75‰ for the red alga Phyllophora antarctica, to -10.35‰ for sea ice POM. Consumers were also well separated by δ 13C, ranging from -21.42‰ for the holothurian Staurocucumis sp. up to -7.47‰ for the urchin Sterechinus neumayeri. Analysis of δ 13C and δ 15N revealed distinct groups for suspension feeders, grazer/herbivores and deposit feeders, whilst predators and predator/scavengers showed less grouping. Consumers spanned a δ 15N range of 8.71‰, equivalent to four trophic levels, although δ 15N ratios amongst consumers were continuous, rather than grouped into discrete trophic levels. The study has built a trophic model for the Windmill Islands and summarises three main carbon pathways utilised by the benthos: (1) pelagic POM; (2) macroalgae/epiphytic/benthic diatoms and (3) sediment POM/benthic diatoms. The movement of carbon within the coastal benthic community of the Windmill Islands is considered complex, and stable isotopes of carbon and nitrogen were valuable tools in determining specific feeding guilds and in tracing carbon flow, particularly amongst lower-order consumers.

  14. Benthic Communities of Low-Order Streams Affected by Acid Mine Drainages: A Case Study from Central Europe

    Directory of Open Access Journals (Sweden)

    Marek Svitok

    2014-05-01

    Full Text Available Only little attention has been paid to the impact of acid mine drainages (AMD on aquatic ecosystems in Central Europe. In this study, we investigate the physico-chemical properties of low-order streams and the response of benthic invertebrates to AMD pollution in the Banská Štiavnica mining region (Slovakia. The studied streams showed typical signs of mine drainage pollution: higher conductivity, elevated iron, aluminum, zinc and copper loads and accumulations of ferric precipitates. Electric conductivity correlated strongly with most of the investigated elements (weighted mean absolute correlation = 0.95 and, therefore, can be recommended as a good proxy indicator for rapid AMD pollution assessments. The diversity and composition of invertebrate assemblages was related to water chemistry. Taxa richness decreased significantly along an AMD-intensity gradient. While moderately affected sites supported relatively rich assemblages, the harshest environmental conditions (pH < 2.5 were typical for the presence of a limited number of very tolerant taxa, such as Oligochaeta and some Diptera (Limnophyes, Forcipomyiinae. The trophic guild structure correlated significantly with AMD chemistry, whereby predators completely disappeared under the most severe AMD conditions. We also provide a brief review of the AMD literature and outline the needs for future detailed studies involving functional descriptors of the impact of AMD on aquatic ecosystems.

  15. Vertebrate interleukins originated in invertebrates?

    Directory of Open Access Journals (Sweden)

    S Gerber

    2007-10-01

    Full Text Available Previous studies have demonstrated that invertebrate immune and neural tissues contain mammalian-like cytokines, which activate specific cellular functions. Therefore, it was of interest to attempt to identify these molecules via Applied Biosystems Human Genome Survey Arrays. The array was used to analyze the transcriptional profiles of Mytilus edulis RNA samples. The Applied Biosystems Human Genome Survey Array contains 31,700 60-mer oligonucleotides probes representing a set of 27, 868 individual human genes and more than 1,000 control probes. We show interleukin-like and tumor necrosis factor-like genes among other cytokine-like genes significantly expressed in this invertebrate tissue with a signal to noise value greater than 2. In morphine treated tissue additional cytokine genes were expressed. These cytokine-like genes are directly related to previously discovered molecules in invertebrates, suggesting that they first appeared earlier in evolution.

  16. Invertebrate drift during in-channel gravel mining: the Upper River Cinca (Southern Pyrenees)

    Science.gov (United States)

    Béjar, Maria; Gibbins, Chris; Vericat, Damià; Batalla, Ramon J.; Muñoz, Efrén; Ramos, Ester; Lobera, Gemma; Andrés López-Tarazón, Jose; Piqué, Gemma; Tena, Álvaro; Buendía, Cristina; Rennie, Colin D.

    2015-04-01

    Invertebrate drift has been widely studied as an important mechanism to structure the benthic assemblages and as a part of invertebrate behavior in fluvial systems. River channel disturbance is considered the main factor affecting the organization of riverine communities and contributes to key ecological processes. However, little is known about involuntary drift associated to bed disturbance due to the difficulties associated with sampling during floods. In-channel gravel mining offers an opportunity to study involuntary drift associated not only to local bed disturbances but also to sudden changes on suspended sediment concentrations and flow. High suspended sediment concentrations and sudden changes in flow also prompt drift due to the limiting conditions (i.e. lack of oxygen, hydric stress). Within this context, invertebrate drift was monitored in the Upper River Cinca (Southern Pyrenees) during two gravel mining activities performed in summer 2014. The data acquisition design includes: drift, suspended sediment, bedload, bed mobility and flow. Data was acquired before, during and after mining at different sampling locations located upstream and downstream the perturbation. Drift and suspended sediment transport were sampled at 5 sections: 1 control site upstream the mining and 4 downstream. Bedload samples were collected just downstream the channel where gravels were extracted. Bed mobility and changes on topography were assessed by means of GPS-aDcp and repeat topographic surveys. Discharge was continuously recorded 2.5 km downstream the mining location. Additionally, two turbidity meters registered water turbidity at 15 minute intervals in two of the four sampling sections located downstream. This experimental design provides data on the spatial and temporal variability of drift associated to a local bed disturbance that (i) changes the distribution of flow across the section where mining was performed, (ii) increase substantially suspended sediment

  17. Benthic diatoms in lakes

    OpenAIRE

    Gottschalk, Steffi

    2014-01-01

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

  18. Benthic community of the Savannah River below a peaking hydropower station

    Science.gov (United States)

    Hudson, Patrick L.; Nichols, S. Jerrine

    1986-01-01

    The Savannah River below Hartwell Dam, on the South Carolina-Georgia border, contains at least 206 benthic invertebrate taxa, even though this tailwater undergoes substantial daily fluctuations in water flow, temperature, and dissolved oxygen. Oligochaetes, chironomids, and amphipods dominate the community immediately below the dam. Farther downstream, larger organisms (i.e., Ephemeroptera, Trichoptera, etc.) dominate the benthic community. The high diversity of this system is primarily attributed to the intensive effort we expended to identify invertebrates to species level. We conclude that tailwaters associated with peaking hydropower stations may in fact have the diverse community assemblages found in natural streams and that this has not been recognized by other investigators because the bulk of the fauna is made up of small forms that are easily overlooked. Comparisons of tailwater fauna communities with those in control areas should be limited to rivers of similar size.

  19. Storm-event-transport of urban-use pesticides to streams likely impairs invertebrate assemblages.

    Science.gov (United States)

    Carpenter, Kurt D; Kuivila, Kathryn M; Hladik, Michelle L; Haluska, Tana; Cole, Michael B

    2016-06-01

    Insecticide use in urban areas results in the detection of these compounds in streams following stormwater runoff at concentrations likely to cause toxicity for stream invertebrates. In this 2013 study, stormwater runoff and streambed sediments were analyzed for 91 pesticides dissolved in water and 118 pesticides on sediment. Detections included 33 pesticides, including insecticides, fungicides, herbicides, degradates, and a synergist. Patterns in pesticide occurrence reveal transport of dissolved and sediment-bound pesticides, including pyrethroids, from upland areas through stormwater outfalls to receiving streams. Nearly all streams contained at least one insecticide at levels exceeding an aquatic-life benchmark, most often for bifenthrin and (or) fipronil. Multiple U.S. EPA benchmark or criterion exceedances occurred in 40 % of urban streams sampled. Bed sediment concentrations of bifenthrin were highly correlated (p insects and tolerant invertebrates such as amphipods, flatworms, nematodes, and oligochaetes dominated streams with relatively high concentrations of bifenthrin in bed sediments, whereas insects, sensitive invertebrates, and mayflies were much more abundant at sites with no or low bifenthrin concentrations. The abundance of sensitive invertebrates, % EPT, and select mayfly taxa were strongly negatively correlated with organic-carbon normalized bifenthrin concentrations in streambed sediments. Our findings from western Clackamas County, Oregon (USA), expand upon previous research demonstrating the transport of pesticides from urban landscapes and linking impaired benthic invertebrate assemblages in urban streams with exposure to pyrethroid insecticides. PMID:27170357

  20. Land Use and Hydrogeological Characteristics Influence Groundwater Invertebrate Communities.

    Science.gov (United States)

    Tione, María Laura; Bedano, José Camilo; Blarasin, Mónica

    2016-08-01

    We examine the influence of land use and hydrogeological characteristics on the abundance, composition and structure of groundwater invertebrate communities in a loessic aquifer from Argentina. Seven wells, selected according to surrounding land use and hydrogeological characteristics, were sampled twice. Groundwater was characterized as sodium bicarbonate, bicarbonate sulfate or sulfate type. NO3(-) was detected in all samples. Land use in the area surrounding the well, unsaturated zone thickness and geochemical characteristics of groundwater influenced the abundance, composition and community structure of groundwater invertebrates. Copepoda, Oligochaeta, Cladocera, Ostracoda and Amphipoda were highly influenced by land use, particularly by point pollution sources that produced higher abundance and changes in taxonomic composition. The lowest invertebrate abundance was observed at the wells situated in areas with the thickest unsaturated zone. Groundwater salinity and geochemical type influenced the presence of certain species, particularly Stygonitocrella sp. PMID:27456146

  1. Divergent ecosystem responses within a benthic marine community to ocean acidification

    OpenAIRE

    Kroeker, Kristy J.; Micheli, Fiorenza; Gambi, Maria Cristina; Martz, Todd R.

    2011-01-01

    Ocean acidification is predicted to impact all areas of the oceans and affect a diversity of marine organisms. However, the diversity of responses among species prevents clear predictions about the impact of acidification at the ecosystem level. Here, we used shallow water CO2 vents in the Mediterranean Sea as a model system to examine emergent ecosystem responses to ocean acidification in rocky reef communities. We assessed in situ benthic invertebrate communities in three distinct pH zones ...

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

    DEFF Research Database (Denmark)

    Sandin, Leif Leonard; Solimini, Angelo G.

    2012-01-01

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

  3. 薇甘菊入侵对中小型土壤动物群落结构特征的影响%Impact of Mikania micrantha invasion on soil meso- and micro-invertebrate community structure

    Institute of Scientific and Technical Information of China (English)

    全国明; 章家恩; 谢俊芳; 毛丹鹃; 徐华勤; 姜万兵; 文杜娟

    2011-01-01

    Mikania micrantha, a notorious exotic weed of Asteraceae family, has invaded successfully in southern China, and caused serious damages to native ecosystems.In this paper, a field survey was conducted in the Huolushan Forest Park of Guangzhou, China, aimed to understand the impact of M.micrantha invasion on the soil meso- and micro-invertebrate community.Three sampling sites were installed, including M.micrantha-invaded site, ecotone, and native vegetation site.Through four samplings in 2009, a total of 5206 soil meso- and micro-invertebrate individuals were collected, belonging to 4 phyla, 10 classes, and 19 orders, among which, Nematoda was the dominant group, and Acarina, Collembolan, and Rotifera were the common groups.M.micrantha invasion altered the characteristics of soil meso- and micro-invertebrate community structure.Compared with those at the other two sampling sites, the numbers of total individuals, Nematoda, and Acarina at M.micrantha-invaded site increased significantly, but the groups of soil meso- and micro-invertebrates had less change.At M.micrantha-invaded site, the density-group index ( DG) of soil meso- and micro-invertebrates was significantly higher, Margalef richness index ( D) and Simpson dominance index ( C) tended to ascend, but Pielou evenness index ( E) and Shannon index (H') tended to descend.The similarity coefficient of soil meso- and micro-invertebrate community between M. micrantha-invaded site and ecotone was higher than that between M.micrantha-invaded site and native vegetation site.The changes of local climate conditions, plant litters, root secretions, and soil physical-chemical properties caused by M.micrantha invasion could be the major contributing factors that altered the community structure of soil meso- and micro-invertebrates at M.micrantha-invaded site.%薇甘菊是菊科假泽兰属的恶性杂草,在我国华南地区已成功入侵并造成严重危害.为了解薇甘菊入侵对土壤动物的影响效应,采用

  4. The impact of global warming and anoxia on marine benthic community dynamics: an example from the Toarcian (Early Jurassic.

    Directory of Open Access Journals (Sweden)

    Silvia Danise

    Full Text Available The Pliensbachian-Toarcian (Early Jurassic fossil record is an archive of natural data of benthic community response to global warming and marine long-term hypoxia and anoxia. In the early Toarcian mean temperatures increased by the same order of magnitude as that predicted for the near future; laminated, organic-rich, black shales were deposited in many shallow water epicontinental basins; and a biotic crisis occurred in the marine realm, with the extinction of approximately 5% of families and 26% of genera. High-resolution quantitative abundance data of benthic invertebrates were collected from the Cleveland Basin (North Yorkshire, UK, and analysed with multivariate statistical methods to detect how the fauna responded to environmental changes during the early Toarcian. Twelve biofacies were identified. Their changes through time closely resemble the pattern of faunal degradation and recovery observed in modern habitats affected by anoxia. All four successional stages of community structure recorded in modern studies are recognised in the fossil data (i.e. Stage III: climax; II: transitional; I: pioneer; 0: highly disturbed. Two main faunal turnover events occurred: (i at the onset of anoxia, with the extinction of most benthic species and the survival of a few adapted to thrive in low-oxygen conditions (Stages I to 0 and (ii in the recovery, when newly evolved species colonized the re-oxygenated soft sediments and the path of recovery did not retrace of pattern of ecological degradation (Stages I to II. The ordination of samples coupled with sedimentological and palaeotemperature proxy data indicate that the onset of anoxia and the extinction horizon coincide with both a rise in temperature and sea level. Our study of how faunal associations co-vary with long and short term sea level and temperature changes has implications for predicting the long-term effects of "dead zones" in modern oceans.

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

    Science.gov (United States)

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

    2012-04-01

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

  6. Population Genetic Structure, Abundance, and Health Status of Two Dominant Benthic Species in the Saba Bank National Park, Caribbean Netherlands: Montastraea cavernosa and Xestospongia muta

    Science.gov (United States)

    de Bakker, Didier M.; Meesters, Erik H. W. G.; van Bleijswijk, Judith D. L.; Luttikhuizen, Pieternella C.; Breeuwer, Hans J. A. J.; Becking, Leontine E.

    2016-01-01

    Saba Bank, a submerged atoll in the Caribbean Sea with an area of 2,200 km2, has attained international conservation status due to the rich diversity of species that reside on the bank. In order to assess the role of Saba Bank as a potential reservoir of diversity for the surrounding reefs, we examined the population genetic structure, abundance and health status of two prominent benthic species, the coral Montastraea cavernosa and the sponge Xestospongia muta. Sequence data were collected from 34 colonies of M. cavernosa (nDNA ITS1-5.8S-ITS2; 892 bp) and 68 X. muta sponges (mtDNA I3-M11 partition of COI; 544 bp) on Saba Bank and around Saba Island, and compared with published data across the wider Caribbean. Our data indicate that there is genetic connectivity between populations on Saba Bank and the nearby Saba Island as well as multiple locations in the wider Caribbean, ranging in distance from 100s–1000s km. The genetic diversity of Saba Bank populations of M. cavernosa (π = 0.055) and X. muta (π = 0.0010) was comparable to those in other regions in the western Atlantic. Densities and health status were determined along 11 transects of 50 m2 along the south-eastern rim of Saba Bank. The densities of M. cavernosa (0.27 ind. m-2, 95% CI: 0.12–0.52) were average, while the densities of X. muta (0.09 ind. m-2, 95% CI: 0.02–0.32) were generally higher with respect to other Caribbean locations. No disease or bleaching was present in any of the specimens of the coral M. cavernosa, however, we did observe partial tissue loss (77.9% of samples) as well as overgrowth (48.1%), predominantly by cyanobacteria. In contrast, the majority of observed X. muta (83.5%) showed signs of presumed bleaching. The combined results of apparent gene flow among populations on Saba Bank and surrounding reefs, the high abundance and unique genetic diversity, indicate that Saba Bank could function as an important buffer for the region. Either as a natural source of larvae to

  7. Population Genetic Structure, Abundance, and Health Status of Two Dominant Benthic Species in the Saba Bank National Park, Caribbean Netherlands: Montastraea cavernosa and Xestospongia muta.

    Directory of Open Access Journals (Sweden)

    Didier M de Bakker

    Full Text Available Saba Bank, a submerged atoll in the Caribbean Sea with an area of 2,200 km2, has attained international conservation status due to the rich diversity of species that reside on the bank. In order to assess the role of Saba Bank as a potential reservoir of diversity for the surrounding reefs, we examined the population genetic structure, abundance and health status of two prominent benthic species, the coral Montastraea cavernosa and the sponge Xestospongia muta. Sequence data were collected from 34 colonies of M. cavernosa (nDNA ITS1-5.8S-ITS2; 892 bp and 68 X. muta sponges (mtDNA I3-M11 partition of COI; 544 bp on Saba Bank and around Saba Island, and compared with published data across the wider Caribbean. Our data indicate that there is genetic connectivity between populations on Saba Bank and the nearby Saba Island as well as multiple locations in the wider Caribbean, ranging in distance from 100s-1000s km. The genetic diversity of Saba Bank populations of M. cavernosa (π = 0.055 and X. muta (π = 0.0010 was comparable to those in other regions in the western Atlantic. Densities and health status were determined along 11 transects of 50 m2 along the south-eastern rim of Saba Bank. The densities of M. cavernosa (0.27 ind. m-2, 95% CI: 0.12-0.52 were average, while the densities of X. muta (0.09 ind. m-2, 95% CI: 0.02-0.32 were generally higher with respect to other Caribbean locations. No disease or bleaching was present in any of the specimens of the coral M. cavernosa, however, we did observe partial tissue loss (77.9% of samples as well as overgrowth (48.1%, predominantly by cyanobacteria. In contrast, the majority of observed X. muta (83.5% showed signs of presumed bleaching. The combined results of apparent gene flow among populations on Saba Bank and surrounding reefs, the high abundance and unique genetic diversity, indicate that Saba Bank could function as an important buffer for the region. Either as a natural source of larvae to

  8. Population Genetic Structure, Abundance, and Health Status of Two Dominant Benthic Species in the Saba Bank National Park, Caribbean Netherlands: Montastraea cavernosa and Xestospongia muta.

    Science.gov (United States)

    de Bakker, Didier M; Meesters, Erik H W G; van Bleijswijk, Judith D L; Luttikhuizen, Pieternella C; Breeuwer, Hans J A J; Becking, Leontine E

    2016-01-01

    Saba Bank, a submerged atoll in the Caribbean Sea with an area of 2,200 km2, has attained international conservation status due to the rich diversity of species that reside on the bank. In order to assess the role of Saba Bank as a potential reservoir of diversity for the surrounding reefs, we examined the population genetic structure, abundance and health status of two prominent benthic species, the coral Montastraea cavernosa and the sponge Xestospongia muta. Sequence data were collected from 34 colonies of M. cavernosa (nDNA ITS1-5.8S-ITS2; 892 bp) and 68 X. muta sponges (mtDNA I3-M11 partition of COI; 544 bp) on Saba Bank and around Saba Island, and compared with published data across the wider Caribbean. Our data indicate that there is genetic connectivity between populations on Saba Bank and the nearby Saba Island as well as multiple locations in the wider Caribbean, ranging in distance from 100s-1000s km. The genetic diversity of Saba Bank populations of M. cavernosa (π = 0.055) and X. muta (π = 0.0010) was comparable to those in other regions in the western Atlantic. Densities and health status were determined along 11 transects of 50 m2 along the south-eastern rim of Saba Bank. The densities of M. cavernosa (0.27 ind. m-2, 95% CI: 0.12-0.52) were average, while the densities of X. muta (0.09 ind. m-2, 95% CI: 0.02-0.32) were generally higher with respect to other Caribbean locations. No disease or bleaching was present in any of the specimens of the coral M. cavernosa, however, we did observe partial tissue loss (77.9% of samples) as well as overgrowth (48.1%), predominantly by cyanobacteria. In contrast, the majority of observed X. muta (83.5%) showed signs of presumed bleaching. The combined results of apparent gene flow among populations on Saba Bank and surrounding reefs, the high abundance and unique genetic diversity, indicate that Saba Bank could function as an important buffer for the region. Either as a natural source of larvae to replenish

  9. Cryptic speciation in a benthic isopod from Patagonian and Falkland Island waters and the impact of glaciations on its population structure

    Directory of Open Access Journals (Sweden)

    Kop Anna

    2008-12-01

    Full Text Available Abstract Background The Falkland Islands and Patagonia are traditionally assigned to the Magellan Biogeographic Province. Most marine species in Falkland waters are also reported from southern Patagonia. It remains unclear if relatively immobile, marine benthic, shallow-water species maintain gene flow, and by what mechanism. Recurrent fluctuations in sea level during glacial cycles are regarded as a possible mechanism that might have allowed genetic exchange between the regions. However, the realized genetic exchange between the Falkland Islands and Patagonia has never been estimated. Results This study analyses the genetic structure of three populations of the marine shallow-water isopod Serolis paradoxa (Fabricius, 1775 from the Falkland Islands and southern Patagonia (central Strait of Magellan and the Atlantic opening applying seven nuclear microsatellites and a fragment of the mitochondrial 16S rRNA gene. Both marker systems report highest genetic diversity for the population from the central Strait of Magellan and lowest for the Falkland Islands. The estimated effective population sizes were large for all populations studied. Significant differentiation was observed among all three populations. The magnitude of differentiation between Patagonia and the Falkland Islands (16S: uncorrected p-distance 2.1%; microsatellites: standardized F'ST > 0.86 was an order of magnitude higher than between populations from within Patagonia. This indicates that there is currently no effective gene flow for nominal S. paradoxa between these two regions and it has been absent for time exceeding the last glacial maximum. We argue that specimens from the Strait of Magellan and the Falkland Islands very likely represent two distinct species that separated in the mid-Pleistocene (about 1 MY BP. Conclusion The results of this study indicate limited gene flow between distant populations of the brooding isopod Serolis paradoxa. The patterns of genetic diversity

  10. Cryptic speciation in a benthic isopod from Patagonian and Falkland Island waters and the impact of glaciations on its population structure

    OpenAIRE

    Kop Anna; Leese Florian; Wägele Johann-Wolfgang; Held Christoph

    2008-01-01

    Abstract Background The Falkland Islands and Patagonia are traditionally assigned to the Magellan Biogeographic Province. Most marine species in Falkland waters are also reported from southern Patagonia. It remains unclear if relatively immobile, marine benthic, shallow-water species maintain gene flow, and by what mechanism. Recurrent fluctuations in sea level during glacial cycles are regarded as a possible mechanism that might have allowed genetic exchange between the regions. However, the...

  11. 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

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

    Science.gov (United States)

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

    1998-01-01

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

  13. 中国北部海域主要无脊椎动物群落结构及多样性%Community structure and diversity of invertebrates in northern region of China Sea

    Institute of Scientific and Technical Information of China (English)

    吴强; 王俊; 金显仕; 李忠义; 陈瑞胜

    2011-01-01

    根据2010年5月、8月在渤海及黄海北部进行的底拖网定点调查资料,分析了中国北部海域无脊椎动物群落结构及其生物多样性.中国北部海域共捕获无脊椎动物32种,其中虾类15种,蟹类10种,头足类7种;在渤海,虾类占主导地位,春季其生物量及密度比例分别为86.57%和96.55%,夏季为46.16%和80.85%;在黄海北部,春季蟹类在生物量组成中占绝对优势地位(91.07%),夏季则为头足类占优势地位(80.41%).运用相对重要性指数(IRI)研究了渤海及黄海北部的优势种类组成,优势种类随季节及海区的变化差异较大.使用多样性指数D、H’、J’分析了无脊椎动物群落的多样性,渤海生物多样性高于黄海北部.分析了渤海及黄海北部群落物种组成相似性,两个海区物种组成相似性分别为春季0.315和夏季0.297.使用季节更替指数和迁移指数研究了两个海区无脊椎动物群落的稳定性,表明从春季至夏季,黄海北部部分种类向渤海迁移.%We evaluated the community structure and diversity of invertebrates in the northern region of China Sea using data collected from bottom trawl surveys in May and August 2010. We collected a total of 32 invertebrate species, including IS species of shrimp, 10 species of crab, and 7 species of squid. Shrimps were dominant in Bohai Sea, accounting for 86.57% of the biomass and 96.55% of individuals in May and 46.16% of the biomass and 80.85% of individuals in August. In contrast, the north region of the Yellow Sea was dominated by crabs in May (91.07% of the biomass) and squid in August (80.41% of the biomass). We quantified the ecological dominance of a species using an index of relative importance (IRI). The dominant species changed between seasons and regions. We calculated three diversity indexes to analyze the diversity of invertebrates: the species abundance index (D), the Shannon-Wiener diversity index (H'), and the species evenness

  14. The effects of riparian forestry on invertebrate drift and brown trout in upland streams of contrasting acidity

    Science.gov (United States)

    Ormerod, S. J.; Jones, M. E.; Jones, M. C.; Phillips, D. R.

    Variations in macroinvertebrate drift and benthic invertebrate abundance were assessed in 30 upland Welsh streams of varying acidity (pH 6.0) and riparian land-use (conifer, moorland or native broadleaf). The consequences for the diet and condition of wild brown trout Salmo trutta were also assessed. As expected from previous studies, there were significant reductions in benthic invertebrate abundance, aquatic drift density (by >60%), aquatic drift biomass (by >35%), total drift density (by >35%) and total drift biomass (by >20%) at acid sites by comparison with circumneutral sites due largely to the scarcity of mayflies. Absolute drift from terrestrial sources was unrelated to stream pH but formed a significantly greater proportion of total drift at acid sites (30-65% of density) than at circumneutral sites (20-40%) as aquatic contributions declined. Most of this apparent land use effect reflected significantly increased terrestrial drift under broadleaves. There was no significant reduction in terrestrial or aquatic drift at conifer forest sites per se after accounting for low pH. Trout diet varied substantially between locations partly reflecting variations in drift: significantly fewer mayflies and stoneflies were eaten at acid sites, and significantly more terrestrial prey were eaten under broadleaves. However, acidity did not reduce trout condition or gut-fullness. Unexpectedly, trout condition was significantly enhanced at conifer sites, irrespective of their pH. Hence, acidity has greater effects on the benthic abundance and drift density of invertebrates in upland streams than does riparian land use. However, trout forage flexibly enough to offset any possible food deficit, for example by switching to chironomids and terrestrial invertebrates. Enhanced terrestrial contributions to invertebrate drift from riparian broadleaf trees may be important in supplementing foraging opportunities for trout where aquatic prey are scarce. These data illustrate the value

  15. GPCRs in invertebrate innate immunity.

    Science.gov (United States)

    Reboul, Jerome; Ewbank, Jonathan J

    2016-08-15

    G-protein coupled receptors (GPCRs) represent a privileged point of contact between cells and their surrounding environment. They have been widely adopted in vertebrates as mediators of signals involved in both innate and adaptive immunity. Invertebrates rely on innate immune defences to resist infection. We review here evidence from a number of different species, principally the genetically tractable Caenorhabditis elegans and Drosophila melanogaster that points to an important role for GPCRs in modulating innate immunity in invertebrates too. In addition to examples of GPCRs involved in regulating the expression of defence genes, we discuss studies in C. elegans addressing the role of GPCR signalling in pathogen aversive behaviour. Despite the many lacunae in our current knowledge, it is clear that GPCR signalling contributes to host defence across the animal kingdom. PMID:27262554

  16. 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.

  17. 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 plasticit...... and memory has long been a matter of debate. A recent study on Anopheles gambiae mosquitoes now establishes Down syndrome cell adhesion molecule (Dscam) as a key immune surveillance factor with characteristics analogous to antibodies....

  18. Marine invertebrates: communities at risk.

    Science.gov (United States)

    Mather, Jennifer

    2013-01-01

    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. PMID:24832811

  19. Stimulation of microbial nitrogen cycling in aquatic ecosystems by benthic macrofauna: mechanisms and environmental implications

    Science.gov (United States)

    Stief, P.

    2013-12-01

    Invertebrate animals that live at the bottom of aquatic ecosystems (i.e., benthic macrofauna) are important mediators between nutrients in the water column and microbes in the benthos. The presence of benthic macrofauna stimulates microbial nutrient dynamics through different types of animal-microbe interactions, which potentially affect the trophic status of aquatic ecosystems. This review contrasts three types of animal-microbe interactions in the benthos of aquatic ecosystems: (i) ecosystem engineering, (ii) grazing, and (iii) symbiosis. Their specific contributions to the turnover of fixed nitrogen (mainly nitrate and ammonium) and the emission of the greenhouse gas nitrous oxide are evaluated. Published data indicate that ecosystem engineering by sediment-burrowing macrofauna stimulates benthic nitrification and denitrification, which together allows fixed nitrogen removal. However, the release of ammonium from sediments is enhanced more strongly than the sedimentary uptake of nitrate. Ecosystem engineering by reef-building macrofauna increases nitrogen retention and ammonium concentrations in shallow aquatic ecosystems, but allows organic nitrogen removal through harvesting. Grazing by macrofauna on benthic microbes apparently has small or neutral effects on nitrogen cycling. Animal-microbe symbioses provide abundant and distinct benthic compartments for a multitude of nitrogen-cycle pathways. Recent studies reveal that ecosystem engineering, grazing, and symbioses of benthic macrofauna significantly enhance nitrous oxide emission from shallow aquatic ecosystems. The beneficial effect of benthic macrofauna on fixed nitrogen removal through coupled nitrification-denitrification can thus be offset by the concurrent release of (i) ammonium that stimulates aquatic primary production and (ii) nitrous oxide that contributes to global warming. Overall, benthic macrofauna intensifies the coupling between benthos, pelagial, and atmosphere through enhanced turnover and

  20. Spatiotemporal variation in community structure of marine benthic ciliates in the Yellow Sea during and after macroalgal and giant jellyfish blooms

    Science.gov (United States)

    Zhou, Bailing; Xu, Kuidong

    2016-07-01

    The annual bloom of the green macroalgal Ulva prolifera from May through July since 2008 and another of giant jellyfish Nemopilema nomurai from June through September have been frequent events in the Yellow Sea. However, the patterns of benthic ciliate communities during and after the blooms are still not known. In combination with analyses of benthic environmental factors, we investigated the distribution and community composition of benthic ciliates in the Yellow Sea in July and November 2011. In July, ciliates had high standing crops and diversity in the northern Yellow Sea, and in the inshore area off the southern Shandong Peninsula, where large numbers of green macroalgae accumulated. In November, the abundance, biomass and diversity of ciliates were high in the sea areas off the Shandong Peninsula and Changjiang estuary, where a large quantity of jellyfish occurred in August. Neither the abundance nor the biomass had significant difference between seasons, or between different compartments of the Yellow Sea. The species number, and both Margalef and Shannon-Wiener indices of ciliates were all significantly higher in November than in July. In both seasons, prostomateans and karyorelicteans consistently constituted the first and second most important ciliate groups in biomass; and carnivorous ciliates constituted the primary feeding type in terms of biomass as well as species richness, followed by bacterivores, algivores and omnivores. Compared with that in June 2007 when no macroalgae occurred, the percentage of small-sized bacterivores (e.g. Metacystis spp., Euplotes spp. and scuticociliates) increased in July 2011. The proportion of carnivorous ciliates increased in November, and this increased dominance of carnivorous ciliates may be a response to the increase in predominance of heterotrophic nanoflagellates, which might in turn be ascribed to an effect of green macroalgal and giant jellyfish blooms in the Yellow Sea.

  1. Biogeochemical and microbial variation across 5500 km of Antarctic surface sediment implicates organic matter as a driver of benthic community structure

    Directory of Open Access Journals (Sweden)

    Deric R Learman

    2016-03-01

    Full Text Available Western Antarctica, one of the fastest warming locations on Earth, is a unique environment that is underexplored with regards to biodiversity. Although pelagic microbial communities in the Southern Ocean and coastal Antarctic waters have been well studied, there are fewer investigations of benthic communities and most have a focused geographic range. We sampled surface sediment from 24 sites across a 5,500 km region of Western Antarctica (covering the Ross Sea to the Weddell Sea to examine relationships between microbial communities and sediment geochemistry. Sequencing of the 16S and 18S rRNA genes showed microbial communities in sediments from the Antarctic Peninsula (AP and Western Antarctica (WA, including the Ross, Amundsen, and Bellingshausen Seas, could be distinguished by correlations with organic matter concentrations and stable isotope fractionation (total organic carbon; TOC, nitrogen, and δ13C. Overall, samples from the AP were higher in nutrient content (TOC, nitrogen, and NH4+ and communities in these samples had higher relative abundances of operational taxonomic units (OTUs classified as the diatom, Chaetoceros, a marine cercozoan and four OTUs classified as Cytophaga or Flavobacteria. As these OTUs were strongly correlated with TOC, the data suggests the diatoms could be a source of organic matter and the Bacteroidetes and cercozoan are grazers that consume the organic matter. Additionally, samples from WA have lower nutrients and were dominated by Thaumarchaeota, which could be related to their known ability to thrive as lithotrophs. This study documents the largest analysis of benthic microbial communities to date in the Southern Ocean, representing almost half the continental shoreline of Antarctica, and documents trophic interactions and coupling of pelagic and benthic communities. Our results indicate potential modifications in carbon sequestration processes related to change in community composition, identifying a

  2. An invertebrate stomach's view on vertebrate ecology

    DEFF Research Database (Denmark)

    Calvignac-Spencer, Sebastien; Leendertz, Fabian H.; Gilbert, M. Thomas P.;

    2013-01-01

    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......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...... should aim at cataloguing invertebrate properties relevant to iDNA retrieval so as to guide future usage of the invertebrate tool box....

  3. Accumulation and effects of sediment-associated silver nanoparticles to sediment-dwelling invertebrates

    DEFF Research Database (Denmark)

    Ramskov, Tina; Forbes, Valery E; Gilliland, Douglas;

    2015-01-01

    Sediment is increasingly recognized as the major sink for contaminants including nanoparticles (NPs). Thus, sediment-living organisms are especially susceptible to NP exposure. Studies of the fate and effects of NPs in the sediment matrix are still in their infancy, and data from such studies are...... in high demand. Here, we examine the effects of exposure to sediment mixed with either aqueous Ag (administered as AgNO3) or Ag NPs (13 nm, citrate-capped) at a nominal exposure concentration of 100 μg Ag/g dry weight sediment on four benthic invertebrates: two clones of the gastropod Potamopyrgus...

  4. National Benthic Infaunal Database (NBID)

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — The NBID is a quantitative database on abundances of individual benthic species by sample and study region, along with other synoptically measured environmental...

  5. Benthic fauna of mangrove environment

    Digital Repository Service at National Institute of Oceanography (India)

    Parulekar, A.H.

    distribution of benthic communities in mangrove environment is governEd. by tidal amplitude, light penetration, nature of substratum and distance from the sea. The littoral zone, neritic zone, Barnacle-oyster zone, Uca zone, Polychaeta zone have been delineated...

  6. NEPR Benthic Habitat Map 2015

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — This benthic habitat map was created from a semi-automated habitat mapping process, using a combination of bathymetry, satellite imagery, aerial imagery and...

  7. 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. PMID:27385510

  8. Population ecology and community structure of sub-tidal soft sediment dwelling macro-invertebrates of Konkan, west coast of India

    Digital Repository Service at National Institute of Oceanography (India)

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

    (Shannon Wiener index) varied from 0.44 to 3.58 (X = 1.94, SD = + or - 0.89). Population and community structure were more stable in premonsoon months. Carnivorous species Glycera alba modified the community structure mainly due to prey-predator...

  9. Arthropod use of invertebrate carrion

    Energy Technology Data Exchange (ETDEWEB)

    Seastedt, T.R.; Mameli, L.; Gridley, K.

    1981-01-01

    Arthropods associated with cricket carcasses placed on top and within deciduous forest litter were collected for 12 months. Vespid wasps and ants quickly removed carcasses left on top of forest litter, but carcasses placed within litter persisted throughout the study. Major consumers of carcasses in litter varied seasonally; maggots dominated on fresh carcasses in summer, but fresh carcasses placed in litter in autumn were consumed by other arthropods. A gamasid mite, Hypoaspis (Laelaspis) johnieae, dominated the microarthropod fauna found on exoskeleton fragments. A method for collecting invertebrate carrion feeders and measuring carrion disappearance is presented. 15 references, 2 tables.

  10. Arthropod use of invertebrate carrion

    Energy Technology Data Exchange (ETDEWEB)

    Seastedt, T.R.; Mameli, L.; Gridley, K.

    1980-08-01

    Arthropods associated with cricket carcasses placed on top and within deciduous forest litter were collected over a 12 month interval. Vespid wasps and ants quickly removed carcasses left on top of forest litter, but carcasses placed within litter persisted throughout the study. Major consumers of carcasses in litter varied seasonally; maggots dominated on fresh carcasses in summer, but fresh carcasses placed in litter in autumn were consumed by other arthropods. A gamasid mite, Hypoaspis (Laelaspis) johnieae dominated the microarthropod fauna found on exoskeleton fragments. A method for collecting invertebrate carrion feeders and measuring carrion disappearance is presented.

  11. Boron in Pariette Wetland Sediments, Aquatic Vegetation & Benthic Organisms

    Science.gov (United States)

    Vasudeva, P.; Jones, C. P.; Powelson, D.; Jacobson, A. R.

    2015-12-01

    The Pariette Wetlands are comprised of 20 ponds located in Utah's Uintah Basin. Boron concentration in the Pariette Wetlands have been observed to exceed the total maximum daily limit of 750 µg L-1. Considering water flow in and out of the wetlands, boron is accumulating within the wetlands where it is sorbed to sediments and bioconcentrated by wetland plant and macro invertebrates. Since boron is an avian teratogen, an estimate of boron ingestion exposure is warranted. Samples from 3 of the 23 Pariette Wetland ponds with one pond near the inlet, one near the outlet, and one in the middle were collected. Five sampling points were designated along a 100 m transect of each pond. At each sampling point duplicate (or triplicate) samples of water, sediments, benthic organisms and wetland vegetation were collected. The sediments were collected with a KB-corer and divided at depths of 0-2 cm, 2-7 cm, and 7+ cm from the sediment surface. Sample splits were sent to the USU Bug lab for identification of invertebrate species. Whenever this transect was not intercepting vegetation, 2-3 additional sample sites were identified at the pond within stands of representative vegetation where bird nests are located. The plant parts used for boron analyses will include seeds, shoot and roots of vascular plants, as well as algae or duckweeds skimmed from the surface. Samples were processed within 2 days of collection. Water samples filtered through a 0.45 μ membrane filter were analyzed for DOC, pH and ECe. The dried and washed vegetation samples were ground and stored. The benthic organisms and macro invertebrates were netted at the water surface. The dried samples were weighed, ground and stored. Samples were weighed, oven dried and reweighed. For plant and macro-invertebrate samples, a nitric and hydrogen peroxide digestion procedure is used to dissolve environmentally available elements. The Hot Water extraction and DTPA-Sorbitol extraction were compared to estimate wetland plant

  12. Nutraceutical functionalities of polysaccharides from marine invertebrates.

    Science.gov (United States)

    Choi, Byeong-Dae; Choi, Yeung Joon

    2012-01-01

    Many researchers are seeking functional materials from marine resources. These marine resources can be used as traditional food additives, and specifically, these are based on polysaccharides. To date, there is a big opportunity to develop new high-value added products with indispensable functional characteristics, which can be used in nutraceuticals either as additives or supplements. Also, a crossover in the pharmaceutical market may be established. Some glycosaminoglycans (GAGs) mimetic-type molecules are already being utilized in the field of nutrition as well as in the cosmetics industry. This chemical is used as a dietary supplement to maintain the structure and function of cartilages, for the relief of pain caused by osteoarthritic joints, and can also be used as an anti-inflammatory agent. Recently, in relation to the prevalence of mad cow disease and avian influenza, the production of GAGs from marine invertebrates offers new market opportunities as compared with that obtained from bovine or avian livestock. PMID:22361178

  13. Biodiversity and Chemical Interactions in Antartic Benthic Communities of Deception Island (South Shetland Islands) = Biodiversidad e Interacciones Químicas en las comunidades bentónicas Antárticas en Isla Decepción

    OpenAIRE

    Angulo Preckler, Carlos

    2015-01-01

    This Thesis covers two different topics in Antarctic marine benthic invertebrates. The two main goals are: 1) to improve the knowledge of the biodiversity of the shallow water benthic communities inside Deception Island (South Shetland Islands, Antarctica), and 2) to establish the chemical ecology of selected Antarctic organisms, by studying the antifouling and antimicrobial activity of their organic extracts. Deception Island is an active volcano on the southwestern end of the...

  14. Assessing and monitoring cryptic reef diversity of colonizing marine invertebrates in Timor-Leste from 2012 to 2014 using the Autonomous Reef Monitoring Structure (ARMS) method

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — To support a long-term program for sustainable management and conservation of coral reef ecosystems, from 2008, Autonomous Reef Monitoring Structures (ARMS) have...

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

    Science.gov (United States)

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

    2013-04-01

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

  16. Benthic Communities of Low-Order Streams Affected by Acid Mine Drainages: A Case Study from Central Europe

    OpenAIRE

    Marek Svitok; Milan Novikmec; Peter Bitušík; Branislav Máša; Jozef Oboňa; Miroslav Očadlík; Eva Michalková

    2014-01-01

    Only little attention has been paid to the impact of acid mine drainages (AMD) on aquatic ecosystems in Central Europe. In this study, we investigate the physico-chemical properties of low-order streams and the response of benthic invertebrates to AMD pollution in the Banská Štiavnica mining region (Slovakia). The studied streams showed typical signs of mine drainage pollution: higher conductivity, elevated iron, aluminum, zinc and copper loads and accumulations of ferric precipitates. Elect...

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

    OpenAIRE

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

    2013-01-01

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

  18. Diversity of litter invertebrates communities from the tunel’na gully in Dnipropetrovsk city

    Directory of Open Access Journals (Sweden)

    V. V. Brygadyrenko

    2012-02-01

    Full Text Available Species community of invertebrates in 10 antropogenically transformed ecosystems on the territory of Tunel’na gully (south-west part of Dnipropetrovsk, Ukraine is investigated. The plant cover of sample areas is shortly described. Taxonomic and ecomorphical structure, indices of biological diversity of litter invertebrate communities are analysed. The invertebrate species inhabited the Tunel’na gully and listed in the Red Data Book of Ukraine and Dnepropetrovsk province are described. The value of the inspected territory for the conservation of rare and endangered animal species is underlined. The creation of new nature protected reservation in the Tunel’na gully is proposed

  19. Characterizing the effects of bisphenol A on sediment-dwelling benthic organisms.

    Science.gov (United States)

    Staples, Charles; Mihaich, Ellen; Ortego, Lisa; Caspers, Norbert; Klečka, Gary; Woelz, Jan; Hentges, Steven

    2016-03-01

    Bisphenol A (BPA) is a high production volume chemical intermediate used primarily in the production of polycarbonate plastics and epoxy resins. It primarily enters surface water and sediment via effluent discharges during its manufacture and use. The physical properties of BPA suggest that sediment is a potential sink and may result in exposure to benthic organisms. Currently there are no studies measuring the chronic toxicity of BPA to benthic organisms via direct sediment exposure. The present study examined the chronic toxicity of BPA to 3 commonly used test organisms that are generally representative of invertebrates occupying the base of the benthic food web and for which standardized testing protocols are available: the oligochaete Lumbriculus variegatus (mean numbers and biomass), the midge Chironomus riparius (emergence and development rate), and the estuarine amphipod Leptocheirus plumulosus (survival, growth, and reproduction). No-observed-effect concentrations (NOECs) for the 3 species ranged from 12 mg/kg to 54 mg/kg dry weight. All NOEC values were higher than all measured concentrations of BPA in freshwater and marine sediments reported in reliable, fully reported studies from North America and Europe from the 1990s to the present. For the first time, there are studies with BPA measuring the chronic toxicity to 3 taxa of sediment dwelling invertebrates, which are suitable to support region-specific risk assessments. PMID:26297924

  20. Structural and functional insights into the ligand-binding domain of a nonduplicated retinoid X nuclear receptor from the invertebrate chordate amphioxus

    OpenAIRE

    Tocchini-Valentini, Guiseppe D.; Rochel, Natacha; Escriva, Hector; Germain, Pierre; Peluso-Iltis, Carole; Paris, Mathilde; Sanglier-Cianferani, Sarah; Van Dorsselaer, Alain; Moras, Dino; Laudet, Vincent

    2009-01-01

    Retinoid X nuclear receptors (RXRs), as well as their insect orthologue, ultraspiracle protein (USP), play an important role in the transcription regulation mediated by the nuclear receptors as the common partner of many other nuclear receptors. Phylogenetic and structural studies have shown that the several evolutionary shifts have modified the ligand binding ability of RXRs. To understand the vertebrate-specific character of RXRs, we have studied the RXR ligand-binding domain of the cephalo...

  1. 黄河口海域无脊椎动物群落结构及其变化%Community structure of invertebrate and its change in Huanghe (Yellow River) Estuary

    Institute of Scientific and Technical Information of China (English)

    张焕君; 李凡; 丛日翔; 丛旭日; 任中华; 吕振波

    2014-01-01

    ,1996. The water and sediment discharge regulation (WSDR) project has been carried out since 2002 by artificially releasing a large amount of water in a short time, which would affect the invertebrate community somewhat to some extent. In order to know the community structure and its seasonal changes of inverte-brate community, the characteristic such as species composition, dominant species, biomass distribution, diversity, and community similarity were studied. Survey were conducted in May, June, early July, late July, August and September, 2012. In the investigated area, 3 sections of 15 sample stations were set up. The distance of the estuary mouth to section A, section B and section C was 10, 20 and 40 km respectively. The 15 stations were radial distributed in the survey area. Data were collected using a beam trawl with a 2.5 m width and a 2 cm net mesh. The trawling speed was~3 knots and each tow lasted~30 min. The results showed that a total number of 45 species, which belongs to 9 orders, 29 class and 39 genus, were collected. The number of species was between 28 and 35 in each survey. Nassarius variciferus, Oratos-quilla oratoria, Diogenes edwardsii, Palaemon gravieri and Neverita didyma were the main species in Huanghe Estuary. Gastropods (a total biomass of 8.4%to 45.8%) and crabs (10.8%–58.6%) were the dominant category of invertebrate by biomass. The trends of seasonal change of biomass and abundance were most similar. Biomass was highest in August and abundance was highest in early July. The Shannon-Wiener diversity index was between 1.482 (in May) and 1.719 (in June). The results of Bray-Curtis similarity and ANOSIM showed that community was more similarly in the adja-cent surveys. But the community in May and June was low similarly with that in August and September. According to the results, we can draw the following conclusions:1) The community was mainly dominated by small low-valued spe-cies. Compared with 1980s, the quality of invertebrate

  2. The complement C3 protein family in invertebrates

    Directory of Open Access Journals (Sweden)

    M Nonaka

    2011-01-01

    Full Text Available Complement C3 plays a pivotal role in the innate immune system of mammals as the central component of the complement system essential for its activation mechanism and effecter function. C3 has a unique intra-chain thioester bond that is shared by some complement and non-complement proteins forming a thioester protein (TEP family. Phylogenetic analysis of TEP family genes of vertebrates and invertebrates revealed that the TEP family is divided into two subfamilies, the C3 subfamily and the alpha-2-macroglobulin (A2M subfamily. The establishment of the TEP genes and differentiation of them into the C3 and A2M subfamilies occurred prior to the divergence of Cnidaria and Bilateria, in a common ancestor of Eumetazoa more than 600 MYA. Since then the A2M subfamily has been retained by all metazoan lineages analyzed thus far. In contrast, the C3 subfamily has been retained only by deuterostomes and some protostomes, and has been lost in multiple protostome lineages. Although the direct functional analysis of the most invertebrate TEPs is still to be performed, conservation of the basic domain structure and functionally important residues for each molecule suggests that the basic function is also conserved. Functional analyses performed on a few invertebrate C3 support this conclusion. The gene duplication events that generated C4 and C5 from C3 occurred in a common ancestor of jawed vertebrates, indicating that invertebrate and cyclostome C3s represent the pre-duplication state. In addition to C3, complement Bf and MASP involved in the activation of C3 are also identified in Cnidaria and some invertebrates, indicating that the complement system is one of the most ancient innate immune systems of Eumetazoa.

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

    Directory of Open Access Journals (Sweden)

    Ludmilla O. Ribeiro

    2005-09-01

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

  4. Do Cement Boulders Mimic Natural Boulders for Macro-Invertebrates in the Southern Caspian Sea?

    OpenAIRE

    Pourjomeh, Fatemeh; Shokri, Mohammad Reza; Kiabi, Bahram

    2014-01-01

    The macro-invertebrates on natural (rock) and artificial (cement) boulders were compared along the southern Caspian Sea and the effect of structural features of boulders (i.e. orientation, facing, surface complexity, the degree of exposure to the wave action) on macro-invertebrate communities were investigated. Ten locations with rock walls in the southern Caspian Sea were investigated in which the isolated boulders of natural and artificial types with similar dimensions were haphazardly ...

  5. Spatial and temporal changes in invertebrate assemblage structure from the entrance to deep-cave zone of a temperate marble cave

    Directory of Open Access Journals (Sweden)

    Benjamin W. Tobin

    2013-09-01

    Full Text Available Seasonality in surface weather results in seasonal temperature and humidity changes in caves. Ecological and physiological differences among trogloxenes, troglophiles, and troglobionts result in species-dependent responses to this variability. To investigate these responses, we conducted five biological inventories in a marble cave in the Sierra Nevada Range, California, USA between May and December 2010. The cave was divided into six quadrats and temperature was continuously logged in each (humidity was logged at the entrance and in the deep cave. With increasing distance from the entrance, temperature changes were increasingly attenuated and lagged relative to surface temperature. Linear regressions were created to determine the relationship between measured environmental variables and diversity for cavernicoles (troglobionts and troglophiles and trogloxenes cave– wide and in the transition zone. Diversity for cavernicoles and trogloxenes peaked in the entrance and deep cave zones, respectively. Quadrat, date, 2-week antecedent temperature average, 2-week antecedent temperature range, and trogloxene abundance explained 76% of cavernicole diversity variability. Quadrat explained 55% of trogloxene diversity variability. In the transition zone, trogloxene abundance explained 26% of cavernicole variability and 2-week antecedent temperature and 2-week antecedent temperature range explained 40% of trogloxene variability. In the transition zone, trogloxene diversity was inversely related to 2-week antecedent temperature average and 2-week antecedent temperature range, suggesting that species were moving into the transition zone when temperature was most stable. In a CCA of cavernicoles distribution data and environmental variables, 35% of variation in species-specific distributions was attributable to quadrat, and non-significant percentages were explained by date and environmental variables. Differences in assemblage structure among quadrats were

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

    Science.gov (United States)

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

    2012-12-01

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

  7. Deep-sea benthic footprint of the deepwater horizon blowout.

    Directory of Open Access Journals (Sweden)

    Paul A Montagna

    Full Text Available The Deepwater Horizon (DWH accident in the northern Gulf of Mexico occurred on April 20, 2010 at a water depth of 1525 meters, and a deep-sea plume was detected within one month. Oil contacted and persisted in parts of the bottom of the deep-sea in the Gulf of Mexico. As part of the response to the accident, monitoring cruises were deployed in fall 2010 to measure potential impacts on the two main soft-bottom benthic invertebrate groups: macrofauna and meiofauna. Sediment was collected using a multicorer so that samples for chemical, physical and biological analyses could be taken simultaneously and analyzed using multivariate methods. The footprint of the oil spill was identified by creating a new variable with principal components analysis where the first factor was indicative of the oil spill impacts and this new variable mapped in a geographic information system to identify the area of the oil spill footprint. The most severe relative reduction of faunal abundance and diversity extended to 3 km from the wellhead in all directions covering an area about 24 km(2. Moderate impacts were observed up to 17 km towards the southwest and 8.5 km towards the northeast of the wellhead, covering an area 148 km(2. Benthic effects were correlated to total petroleum hydrocarbon, polycyclic aromatic hydrocarbons and barium concentrations, and distance to the wellhead; but not distance to hydrocarbon seeps. Thus, benthic effects are more likely due to the oil spill, and not natural hydrocarbon seepage. Recovery rates in the deep sea are likely to be slow, on the order of decades or longer.

  8. Matching biological traits to environmental conditions in marine benthic ecosystems

    Science.gov (United States)

    Bremner, J.; Rogers, S. I.; Frid, C. L. J.

    2006-05-01

    The effects of variability in environmental conditions on species composition in benthic ecosystems are well established, but relatively little is known about how environmental variability relates to ecosystem functioning. Benthic invertebrate assemblages are heavily involved in the maintenance of ecological processes and investigation of the biological characteristics (traits) expressed in these assemblages can provide information about some aspects of functioning. The aim of this study was to establish and explore relationships between environmental variability and biological traits expressed in megafauna assemblages in two UK regions. Patterns of trait composition were matched to environmental conditions and subsets of variables best describing these patterns determined. The nature of the relationships were subsequently examined at two separate scales, both between and within the regions studied. Over the whole area, some traits related to size, longevity, reproduction, mobility, flexibility, feeding method, sociability and living habit were negatively correlated with salinity, sea surface temperature, annual temperature range and the level of fishing effort, and positively associated with fish taxon richness and shell content of the substratum. Between the two regions, reductions in temperature range and shell content were associated with infrequent relative occurrences of short-lived, moderately mobile, flexible, solitary, opportunistic, permanent-burrow dwelling fauna and those exhibiting reproductive strategies based on benthic development. Relationships between some traits and environmental conditions diverged within the two regions, with increases in fishing effort and shell content of the substratum being associated with low frequencies of occurrence of moderately mobile and moderately to highly flexible fauna within one region, but high frequencies in the other. These changes in trait composition have implications for ecosystem processes, with, for

  9. 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. PMID:26531711

  10. Chemical and pharmacological significance of natural guanidines from marine invertebrates.

    Science.gov (United States)

    Ebada, S S; Proksch, P

    2011-03-01

    Natural Guanidines from marine invertebrates represent a group of bioactive secondary metabolites that revealed prominent pharmacological activities such as antimicrobial, antiproliferative, analgesic, and anti-coagulant properties. Acyclovir (Zovirax(®)), the first guanidine-derived pharmaceutical for the treatment of herpes infections since late 1970s, was synthesized based on a marine arabinosyl nucleoside, spongosine. Recently, ziconotide (Prialt(®)), a synthetic form of the marine-derived peptide (ω-conotoxin MVIIA) comprising a guanidine moiety, has been approved for the treatment of chronic pain. This review surveys over 130 compounds of guanidine-containing secondary metabolites from marine invertebrates with emphasis on their pharmacological significance and structure-activity relationships. PMID:21534931

  11. Phototoxicity of petroleum products to marine invertebrate larvae and niles

    International Nuclear Information System (INIS)

    Ultraviolet light can activate certain polycyclic aromatic hydrocarbons (PAHs), inducing the production of free radicals. In biological organisms these free radicals destroy tissues, causing up to a 4,000 fold increase in toxicity. This dramatic response is a potential marker for PAH contamination in environmental samples. Ultraviolet enhancement of toxicity has ecological relevance as well. An oil spill can release large amounts of PAHs into the marine environment. Oil spill assessments to date have not included observations of any phototoxic effect on pelagic larvae or juveniles of benthic or epibenthic invertebrates. In this study, larvae and juveniles of the bivalve, Mulinia lateralis and juveniles of the mysid shrimp, Mysidopsis bahia were exposed to individual PAHs, as well as the water accommodated fractions of several petroleum products to verify the ability of this method to detect PAHs in environmental samples, and to determine if phototoxicity is a concern during and after an oil spill. Significant phototoxicity was seen in both single chemical and petroleum product exposures. Swartz's EPAH model was not applicable to the authors' results. They hoped to show causality but were not fully successful due to the need to further develop the model with their species and expand the number of PAH analyzed

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

    Directory of Open Access Journals (Sweden)

    R. BEDINI

    2014-07-01

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

  13. Enhancement of Linear Agricultural Areas to Provide Invertebrates as Potential Food for Breeding Birds

    Directory of Open Access Journals (Sweden)

    Tracy R. Evans

    2016-07-01

    Full Text Available Birds are an important part of the agricultural landscape, as having nature value, but also as pest control agents and bio-indicators for the health of the environment. Here we look at linear non-crop elements in agricultural areas as a potential source of food for nestlings of avian species. We measured invertebrate availability as it relates to structural complexity at the local and landscape levels in three counties in central Illinois. Invertebrates were measured with taxonomic diversity, abundance, and estimated biomass during spring of 2012 and 2013. Our study shows that easily modifiable field edge characteristics have the greatest impact on invertebrate diversity and abundance, as compared to field and landscape features. This finding shows that a potential invertebrate food source as measured by both diversity and biomass, may be easily enhanced without changes to agricultural practices.

  14. [Invertebrate survey: Fish Springs National Wildlife Refuge

    Data.gov (United States)

    US Fish and Wildlife Service, Department of the Interior — The primary objective of this study was to investigate the premise that invertebrate species diversity and abundance increases significantly following a draw down,...

  15. Are invertebrates relevant models in ageing research?

    DEFF Research Database (Denmark)

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

    2016-01-01

    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...

  16. Bromeliads in Caatinga: an oasis for invertebrates

    OpenAIRE

    Priscila Islair; Karine Santana Carvalho; Fabio Cop Ferreira; Juliana Zina

    2015-01-01

    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 compositi...

  17. Invertebrate Iridovirus Modulation of Apoptosis

    Institute of Scientific and Technical Information of China (English)

    Trevor Williams; Nllesh S. Chitnis; Sh(a)n L. Bilimoria

    2009-01-01

    Programmed cell death (apoptosis) is a key host response to virus infection. Viruses that can modulate host apoptotic responses are likely to gain important opportunities for transmission. Here we review recent studies that demonstrate that particles of Invertebrate iridescent virus 6 (IIV-6) (Iridoviridae, genus Iridovirus), or an IIV-6 virion protein extract, are capable of inducing apoptosis in lepidopteran and coleopteran cells, at concentrations 1000-fold lower than that required to shut-off host macromolecular synthesis. Induction of apoptosis depends on endocytosis of one or more heat-sensitive virion component(s). Studies with a JNK inh ibitor(SP600125) indicated that the JNK signaling pathway is significantly involved in apoptosis in IIV-6 infections of Choristoneurafumiferana ceils. The genome of IIV-6 codes for an inhibitor of apoptosis iap gene (193R) that encodes a protein of 208 aa with 15% identity and 28% similarity in its amino acid sequence to IAP-3 from Cydia pomonella ganulovirus (CpGV). Transcription of IIV-6 iap did not require prior DNA or protein synthesis, indicating that it is an immediate-early class gene. Transient expression and gene knockdown studies have confirmed the functional nature of the IIV-6 iap gene. We present a tentative model for IIV-6 induction and inhibition of apoptosis in insect cells and discuss the potential applications of these findings in insect pest control.

  18. Methanotrophic symbioses in marine invertebrates.

    Science.gov (United States)

    Petersen, Jillian M; Dubilier, Nicole

    2009-10-01

    Symbioses between marine animals and aerobic methane-oxidizing bacteria are found at hydrothermal vents and cold seeps in the deep sea where reduced, methane-rich fluids mix with the surrounding oxidized seawater. These habitats are 'oases' in the otherwise nutrient-poor deep sea, where entire ecosystems are fueled by microbial chemosynthesis. By associating with bacteria that gain energy from the oxidation of CH4 with O2 , the animal host is indirectly able to gain nutrition from methane, an energy source that is otherwise only available to methanotrophic microorganisms. The host, in turn, provides its symbionts with continuous access to both electron acceptors and donors that are only available at a narrow oxic - anoxic interface for free-living methanotrophs. Symbiotic methane oxidizers have resisted all attempts at cultivation, so that all evidence for these symbiotic associations comes from ultrastructural, enzymatic, physiological, stable isotope and molecular biological studies of the symbiotic host tissues. In this review, we present an overview of the habitats and invertebrate hosts in which symbiotic methane oxidizers have been found, and the methods used to investigate these symbioses, focusing on the symbioses of bathymodiolin mussels that have received the most attention among methanotrophic associations. PMID:23765884

  19. 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. PMID:26628222

  20. 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.

  1. 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

  2. Managing fisheries to conserve North Sea groundfish and benthic invertebrate species diversity

    NARCIS (Netherlands)

    Greenstreet, S.P.R.; Robinson, L.; Callaway, R.; Reiss, H.; Ehrich, S.; Piet, G.J.; Kroncke, I.; Craeymeersch, J.A.M.

    2007-01-01

    Concerns over man’s impact on the environment and ecosystems of the world have resulted in a shift in emphasis in the management of marine natural resources. Consequently, an ecosystem approach to management (EAM) is in the process of being developed and implemented for the North Sea

  3. Continental-scale patterns in benthic invertebrate diversity: insights from the MacroBen database

    OpenAIRE

    Paul E Renaud; Webb, T. J.; Bjørgesæter, A.; Karakassis, Ioannis; Kedra, M; Kendall, M. A.; Labrune, C; Lampadariou, N.; Somerfield, P.J.; Wlodarska-Kowalczuk, M.; Vanden Berghe, E.; Claus, S.; Aleffi, I.F.; Amouroux, J.M.; Bryne, K.H.

    2009-01-01

    Latitudinal clines in species diversity in limnic and terrestrial habitats have been noted for well over a century and are consistent across many taxonomic groups. However, studies in marine systems over the past 2 to 3 decades have yielded equivocal results. We conducted initial analyses of the MarBEF (EU Network of Excellence for Marine Biodiversity and Ecosystem Function) database to test for trends in local and regional diversity over the latitudinal extent of European contine...

  4. Trace element exposure in benthic invertebrates from Grove Pond, Plow Shop Pond, and Nonacoicus Brook

    Data.gov (United States)

    US Fish and Wildlife Service, Department of the Interior — Remedial investigations associated with the Superfund Program of the U.S. Environmental Protection Agency (EPA) found highly elevated levels of several trace...

  5. Chemical monitoring in the Dutch Wadden Sea by means of benthic invertebrates and fish

    Science.gov (United States)

    Essink, Karel

    1989-09-01

    In monitoring, it is of utmost importance to carefully define the purpose, the sampling strategy, as well as the analytical chemical and statistical requirements. Surveys are appropriate for describing the geographical variation in environmental contaminant levels. Repeated surveys and recurrentdata collection at permanent locations provide means of detecting temporal trends. Results are presented here of surveys on pollution by trace metals, polychlorinated biphenyls and organochlorine pesticides in the Ems Estuary and Dutch Wadden Sea using Mytilus edulis, Mya arenaria, Arenicoia marina, Nereis diversicolor and Crangon crangon as test organisms. Trends towards decreasing pollution by mercury are illustrated by monitoring data on Mytilus edulis and Zoarces viviparus. It is stressed that the results of chemical monitoring in organisms may be interpreted only in termser the biological effects on the basis of relevant toxicological knowledge and/or additional bio-assays.

  6. Bioaccumulation kinetics of sediment-associated DE-83 in benthic invertebrates (Nereis succinea, polychaete).

    Science.gov (United States)

    Tian, Shengyan; Zhu, Lingyan

    2011-06-01

    Polychaetes (Nereis succinea) were exposed to DE-83 contaminated sediments to investigate the bioaccumulation and bioavailability of nona- and deca-BDEs in sediment. All the major congeners in DE-83 were bioavailable to the lugworms. The uptake coefficients (K(s)) of nona- and deca-BDE congeners in lugworms were in the range of 0.18-0.65 (d(-1)), with the values of BDE-207 and -208 slightly higher than those of BDE-206 and -209. Elimination of nona- and deca-BDE congeners from lugworms was very fast. The estimated half-lives of nona- and deca-BDE congeners in the lugworms were at 0.7d. The bioavailability of nona- and deca-BDE congeners was very low, with BSAF of 0.017 for BDE-206 and -209 and 0.054 for BDE-207 and -208. These may be due to the large molecular size and high affinity of PBDEs to sediment particles. The contribution of BDE-206 in the profile of nona-BDEs in lugworm tissue decreased with exposure time while those of BDE-207 and -208 increased, which could be the result of the biotransformation of BDE-209 to BDE-207 and -208. PMID:21356541

  7. Trace element and stable isotope analysis of fourteen species of marine invertebrates from the Bay of Fundy, Canada.

    Science.gov (United States)

    English, Matthew D; Robertson, Gregory J; Mallory, Mark L

    2015-12-15

    The Bay of Fundy, Canada, is a macrotidal bay with a highly productive intertidal zone, hosting a large abundance and diversity of marine invertebrates. We analysed trace element concentrations and stable isotopic values of δ(15)N and δ(13)C in 14 species of benthic marine invertebrates from the Bay of Fundy's intertidal zone to investigate bioaccumulation or biodilution of trace elements in the lower level of this marine food web. Barnacles (Balanus balanus) consistently had significantly greater concentrations of trace elements compared to the other species studied, but otherwise we found low concentrations of non-essential trace elements. In the range of trophic levels that we studied, we found limited evidence of bioaccumulation or biodilution of trace elements across species, likely due to the species examined occupying similar trophic levels in different food chains. PMID:26490410

  8. Complexity and simplification in understanding recruitment in benthic populations

    KAUST Repository

    Pineda, Jesús

    2008-11-13

    Research of complex systems and problems, entities with many dependencies, is often reductionist. The reductionist approach splits systems or problems into different components, and then addresses these components one by one. This approach has been used in the study of recruitment and population dynamics of marine benthic (bottom-dwelling) species. Another approach examines benthic population dynamics by looking at a small set of processes. This approach is statistical or model-oriented. Simplified approaches identify "macroecological" patterns or attempt to identify and model the essential, "first-order" elements of the system. The complexity of the recruitment and population dynamics problems stems from the number of processes that can potentially influence benthic populations, including (1) larval pool dynamics, (2) larval transport, (3) settlement, and (4) post-settlement biotic and abiotic processes, and larval production. Moreover, these processes are non-linear, some interact, and they may operate on disparate scales. This contribution discusses reductionist and simplified approaches to study benthic recruitment and population dynamics of bottom-dwelling marine invertebrates. We first address complexity in two processes known to influence recruitment, larval transport, and post-settlement survival to reproduction, and discuss the difficulty in understanding recruitment by looking at relevant processes individually and in isolation. We then address the simplified approach, which reduces the number of processes and makes the problem manageable. We discuss how simplifications and "broad-brush first-order approaches" may muddle our understanding of recruitment. Lack of empirical determination of the fundamental processes often results in mistaken inferences, and processes and parameters used in some models can bias our view of processes influencing recruitment. We conclude with a discussion on how to reconcile complex and simplified approaches. Although it

  9. The Global Invertebrate Genomics Alliance (GIGA). 2014. Developing Community Resources to Study Diverse Invertebrate Genomes

    NARCIS (Netherlands)

    Pomponi, S.A.

    2014-01-01

    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 network of diverse scientists to tackle major cha

  10. [Community Structure of Aquatic Community and Evaluation of Water Quality in Laovingyan Section of Dadu River].

    Science.gov (United States)

    Huang, You-you; Zeng, Yu; Liu, Shou-jiang; Ma, Yong-hong; Xu, Xiao

    2016-01-15

    In order to understand the aquatic community structure in the Laoyingyan section of the Dadu River, we collected samples from 9 aquatic sampling points along that section, and studied the phycophyta, zooplankton, benthic invertebrate and fish in them; we also used expert scoring method based on the actual situation of the river to weigh different biome. The water quality was evaluated using comprehensive evaluation of water quality index ( CEWI). The results showed that: (1) there were a total of 105 phycophyta species, belonging to 6 phyla,31 families, and 56 genera in the Laoyingyan section of the Dadu River, among which, diatom species had a higher richness than the others. The mean cell density of the phycophyta was 17.997 8 x 10(4) ind x L(-1), the mean biomass was 0.4463 mg x L(-1), and the highest population density sites were LTS, LYH and XSH. (2) there were a total of 26 zooplankton species, belonging to 3 phyla, 11 families, and 12 genera, among which, Protozoa had a higher richness than the others, accounting for 80.77% of all the zooplankton species; The mean density of the phycophyta was 40.89 ind x L(-1), and the mean biomass was 13.26 x 10(-3) mg x L(-1). The whole community composition was simple, characterized by few species and small population size. (3) there were a total of 14 benthic invertebrate species, belonging to 6 phyla,14 families, and 14 genera, among which, insecta had a higher richness than the others, accounting for 57.16% of the benthic invertebrate species. Benthic invertebrate had higher population densities in LYH and XSH. (4) The mean CEWI of the whole river water was 2. 698 28, characterized by slightly polluted water quality. The CEWI value between every collection point and the individual water quality evaluation index showed a significant positive correlation, manifesting a high consistency. In addition, the water quality of SLH and NYH was mesosaprobic (1 3), among which the worst was SLH with a lowest CEWI of 1.6207, and

  11. 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

    organic matter in sediment and soils, it is particularly important to determine their effects on freshwater mussels and other freshwater benthic invertebrates in contact with sediments, as available toxicity studies with pelagic species, mainly Daphnia magna, may not be representative of these benthic organisms. Finally, there is a critical need for studies of the chronic effects of fungicides on reproduction, immunocompetence, and ecosystem function; sublethal endpoints with population and community-level relevance.

  12. Differential bioaccumulation of potentially toxic elements in benthic and pelagic food chains in Lake Baikal.

    Science.gov (United States)

    Ciesielski, Tomasz M; Pastukhov, Mikhail V; Leeves, Sara A; Farkas, Julia; Lierhagen, Syverin; Poletaeva, Vera I; Jenssen, Bjørn M

    2016-08-01

    Lake Baikal is located in eastern Siberia in the center of a vast mountain region. Even though the lake is regarded as a unique and pristine ecosystem, there are existing sources of anthropogenic pollution to the lake. In this study, the concentrations of the potentially toxic trace elements As, Cd, Pb, Hg, and Se were analyzed in water, plankton, invertebrates, and fish from riverine and pelagic influenced sites in Lake Baikal. Concentrations of Cd, Hg, Pb and Se in Lake Baikal water and biota were low, while concentrations of As were similar or slightly higher compared to in other freshwater ecosystems. The bioaccumulation potential of the trace elements in both the pelagic and the benthic ecosystems differed between the Selenga Shallows (riverine influence) and the Listvenichnyĭ Bay (pelagic influence). Despite the one order of magnitude higher water concentrations of Pb in the Selenga Shallows, Pb concentrations were significantly higher in both pelagic and benthic fish from the Listvenichnyĭ Bay. A similar trend was observed for Cd, Hg, and Se. The identified enhanced bioavailability of contaminants in the pelagic influenced Listvenichnyĭ Bay may be attributed to a lower abundance of natural ligands for contaminant complexation. Hg was found to biomagnify in both benthic and pelagic Baikal food chains, while As, Cd, and Pb were biodiluted. At both locations, Hg concentrations were around seven times higher in benthic than in pelagic fish, while pelagic fish had two times higher As concentrations compared to benthic fish. The calculated Se/Hg molar ratios revealed that, even though Lake Baikal is located in a Se-deficient region, Se is still present in excess over Hg and therefore the probability of Hg induced toxicity in the endemic fish species of Lake Baikal is assumed to be low. PMID:27130338

  13. Application of "taxocene surrogation" and "taxonomic sufficiency" concepts to fish farming environmental monitoring. Comparison of BOPA index versus polychaete assemblage structure.

    Science.gov (United States)

    Aguado-Giménez, F; Gairín, J I; Martinez-Garcia, E; Fernandez-Gonzalez, V; Ballester Moltó, M; Cerezo-Valverde, J; Sanchez-Jerez, P

    2015-02-01

    "Taxocene surrogation" and "taxonomic sufficiency" concepts were applied to the monitoring of soft bottoms macrobenthic assemblages influenced by fish farming following two approaches. Polychaete assemblage evaluation through multivariate analysis and the benthic index BOPA were compared. Six fish farms along the Spanish Mediterranean coast were monitored. Polychaete assemblage provided a suitable picture of the impact gradient, being correlated with total free sulphides. BOPA did not support the impact gradient described by the polychaete assemblage, providing erroneous categorizations. The inclusion of several polychaete families, which were locally identified as indicative of affection to recalculate BOPA, resulted in an improved diagnosis and correlation with the impact gradient. Nevertheless, frequent misclassifications occurred. These results suggest that the structure of polychaete families, sulphides and granulometry conform an appropriate strategy for fish farming monitoring. Biotic indices need to be specifically designed for concrete activities, and regionally validated, because of the environmental plasticity of benthic invertebrates. PMID:25460059

  14. Identifying the components of ecological variation in a marine benthic megafauna

    Directory of Open Access Journals (Sweden)

    Ana Maria Setubal Pires-Vanin

    2001-01-01

    Full Text Available Current work in benthic ecology highlights the importance of the temporal component of ecological variation for distribution and abundance of organisms. However, this approach is limited by the difficulty in separating and measure the constituents of such variation. The present study aims to separate and identify the environmental and temporal components of ecological variation in the abundance of the benthic invertebrate community from the São Sebastião Channel, southeastern Brazil, by canonical correspondence analysis. The area is seasonally submitted to the intrusion of a cold and saline water mass, an important factor influencing benthic communities. The composition and abundance of the megafauna were investigated at five sites from November 1993 to August 1994. A total of 93 species were collected. Average density reached 187 individuals per catch with highest numbers in summer. A striking difference in species composition and abundance was observed in the catches through the year and the results suggested a different structure of the assemblages for each season. Four independent components of the species variation could be separated and identified: pure environmental, pure temporal, environmental with temporal structure and undetermined. The large amount of environmental variation is related to sandy bottoms and depth influence, whereas the time factor can be interpreted as both the seasonal intrusion of the South Atlantic Central Water and the biological cycles of some key-species.Os estudos atuais em ecologia bêntica apontam para a importância do componente temporal da variação ecológica na distribuição e abundância dos organismos. Entretanto, a abordagem temporal é limitada pela dificuldade na separação e quantificação dos constituintes dessa variação. O presente estudo visa separar e quantificar os componentes ambiental e temporal da variação ecológica na distribuição da megafauna bêntica no Canal de São Sebasti

  15. Benthic microbial communities of coastal terrestrial and ice shelf Antarctic meltwater ponds

    OpenAIRE

    Archer, Stephen D. J.; McDonald, Ian R.; Herbold, Craig W.; Lee, Charles K; Cary, Craig S.

    2015-01-01

    The numerous perennial meltwater ponds distributed throughout Antarctica represent diverse and productive ecosystems central to the ecological functioning of the surrounding ultra oligotrophic environment. The dominant taxa in the pond benthic communities have been well described however, little is known regarding their regional dispersal and local drivers to community structure. The benthic microbial communities of 12 meltwater ponds in the McMurdo Sound of Antarctica were investigated to ex...

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

    OpenAIRE

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

    2011-01-01

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

  17. Alkaloids from Marine Invertebrates as Important Leads for Anticancer Drugs Discovery and Development

    Directory of Open Access Journals (Sweden)

    Concetta Imperatore

    2014-12-01

    Full Text Available The present review describes research on novel natural antitumor alkaloids isolated from marine invertebrates. The structure, origin, and confirmed cytotoxic activity of more than 130 novel alkaloids belonging to several structural families (indoles, pyrroles, pyrazines, quinolines, and pyridoacridines, together with some of their synthetic analogs, are illustrated. Recent discoveries concerning the current state of the potential and/or development of some of them as new drugs, as well as the current knowledge regarding their modes of action, are also summarized. A special emphasis is given to the role of marine invertebrate alkaloids as an important source of leads for anticancer drug discovery.

  18. Scavenging on invertebrate carcass in different agricultural habitats

    OpenAIRE

    Fiala, Jan

    2011-01-01

    This thesis was created as a grant application for project funding. The thesis deals with trophic functions and abundances of invertebrates scavengers on dead invertebrates in two model agriculture habitats (meadow and field).

  19. 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., ...

  20. Anthropogenic sources of underwater sound can modify how sediment-dwelling invertebrates mediate ecosystem properties

    Science.gov (United States)

    Solan, Martin; Hauton, Chris; Godbold, Jasmin A.; Wood, Christina L.; Leighton, Timothy G.; White, Paul

    2016-02-01

    Coastal and shelf environments support high levels of biodiversity that are vital in mediating ecosystem processes, but they are also subject to noise associated with mounting levels of offshore human activity. This has the potential to alter the way in which species interact with their environment, compromising the mediation of important ecosystem properties. Here, we show that exposure to underwater broadband sound fields that resemble offshore shipping and construction activity can alter sediment-dwelling invertebrate contributions to fluid and particle transport - key processes in mediating benthic nutrient cycling. Despite high levels of intra-specific variability in physiological response, we find that changes in the behaviour of some functionally important species can be dependent on the class of broadband sound (continuous or impulsive). Our study provides evidence that exposing coastal environments to anthropogenic sound fields is likely to have much wider ecosystem consequences than are presently acknowledged.

  1. Mechanisms of temporary adhesion in benthic animals

    NARCIS (Netherlands)

    Dodou, D.; Breedveld, P.; Winter, J.C.F.; Dankelman, J.; Leeuwen, van J.L.

    2011-01-01

    Adhesive systems are ubiquitous in benthic animals and play a key role in diverse functions such as locomotion, food capture, mating, burrow building, and defence. For benthic animals that release adhesives, surface and material properties and external morphology have received little attention compa

  2. 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.

  3. Acoustic scattering properties of freshwater invertebrates

    Czech Academy of Sciences Publication Activity Database

    Frouzová, Jaroslava; Kubečka, Jan; Matěna, Josef

    Netherlands : Delft University of Technology, 2004 - (Simons, D.), s. 319-324 ISBN 90-5986-079-9. [European Conference on Underwater Acoustic /7./. Delft (NL), 05.07.2004-08.07.2004] R&D Projects: GA AV ČR(CZ) IAA6017201 Keywords : invertebrates * target strength Subject RIV: BI - Acoustics

  4. CONTRIBUTIONS OF INVERTEBRATE PATHOLOGY TO VECTOR CONTROL

    Science.gov (United States)

    Control of the invertebrate host is an integral part of any integrated program to prevent the spread of vector borne diseases of man and animals. This includes important mosquito borne arboviruses such as yellow fever, dengue and the various types of encephalitis including West Nile Virus, St. Loui...

  5. Dietary habits of invasive Ponto-Caspian gobies in the Croatian part of the Danube River basin and their potential impact on benthic fish communities.

    Science.gov (United States)

    Piria, Marina; Jakšić, Goran; Jakovlić, Ivan; Treer, Tomislav

    2016-01-01

    Invasive Ponto-Caspian (P-C(1)) gobies have recently caused dramatic changes in fish assemblage structures throughout the Danube basin. While their presence in the Croatian part of the basin has been noted and distribution studied, their dietary habits and impacts on native fish communities have, until now, been unknown. In 2011, 17 locations in the Sava River Basin were sampled for fish and 15 for benthic invertebrates. Fish population monitoring data, available for nine seasons (2003-2006 and 2010-2014) and 12 locations, were used to analyse the impacts of P-C gobies on benthic fish abundance. Gut content analysis indicates that the monkey goby Neogobius fluviatilis diet is very diverse, but dominated by Trichoptera, Chironomidae, Bivalvia and Odonata. The diet overlaps considerably with the round goby Neogobius melanostomus diet, although Gastropoda are dominant in the latter's diet. Small fish and Gammarus sp. dominate the bighead goby Ponticola kessleri diet. Comparison of gut content with the prey available in the environment indicates that monkey and round gobies exhibit preference for Trichoptera, Megaloptera and Coleoptera, and bighead goby for Trichoptera, Gammarus sp. and Pisces. P-C gobies in the Sava River are spreading upstream, towards the reaches with lower fish diversity. Analyses indicate potentially positive impacts of P-C gobies' presence on some fish populations: round and bighead goby on Balkan golden loach Sabanejewia balcanica and monkey goby on common carp Cyprinus carpio, crucian carp Carassius carassius, burbot Lota lota and Balkan loach Cobitis elongata. However, there are also indications that bighead and round goby could adversely impact the native chub Squalius cephalus and zingel Zingel zingel populations, respectively. As P-C gobies are still in the expansionary period of invasion and the ecosystem still adapting to new circumstances, continued monitoring of fish population dynamics in the Sava basin is needed to determine the

  6. Ecological and evolutionary implications of immunological priming in invertebrates

    OpenAIRE

    Tom J Little; Kraaijeveld, Alex R

    2004-01-01

    Invertebrates have an immune response that differs considerably from the acquired immune response found in vertebrates. However, new studies indicate that past experience with a pathogen can provide individual invertebrates, or their descendants, with enhanced immunity. This prophylactic effect, termed immunological priming, is functionally similar to the acquired immune response in vertebrates. This newfound complexity of invertebrate immunity begs investigation into the conditions under ...

  7. Diversity patterns of benthic macrofauna caused by marine fish farming

    OpenAIRE

    Arnaldo Marín; Carlos Sanz-Lázaro

    2011-01-01

    This paper reviews the patterns observed in the diversity and structure of the macrofauna benthic community under the influence of fish farming. First, we explain the effects of organic enrichment on the sediment and the consequences for the inhabiting communities. We describe the diversity trends in spatial and temporal gradients affected by fish farming and compare them with those described by the Pearson and Rosenberg model. We found that in general terms, the trends of...

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

    Science.gov (United States)

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

    2012-12-01

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

  9. Microphytobenthos in ecotoxicology: a review of the use of marine benthic diatoms in bioassays.

    Science.gov (United States)

    Araújo, Cristiano V M; Blasco, Julián; Moreno-Garrido, Ignacio

    2010-08-01

    Contamination in coastal zones is an increasing problem that adversely affects biological diversity and the functioning of coastal ecosystems. Sediment is an important compartment of these zones since large quantities of diverse contaminants can accumulate there. Whole-sediment toxicity assays are of increasing importance, and several assay methods using mainly invertebrates have been developed. However, an important part of the benthic community, the microphytobenthos (represented principally by benthic diatoms and cyanobacteria), has surprisingly been neglected. Recently, comprehensive studies have been conducted using benthic marine microalgae with the object of establishing a toxicity assay method for sediment samples. The main results published to date in the literature and obtained by our own team have been compiled and are discussed in this review. The value and feasibility of using certain organisms of the microphytobenthos group in ecotoxicology studies are also discussed, and a sediment quality guideline based on multivariate procedure has been derived from data obtained in previous studies. Finally, future perspectives for research in this field are discussed. PMID:20493528

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

    OpenAIRE

    GIGA Community of Scientists

    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 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 la...

  11. Consequences of increasing hypoxic disturbance on benthic communities and ecosystem functioning.

    Directory of Open Access Journals (Sweden)

    Anna Villnäs

    Full Text Available Disturbance-mediated species loss has prompted research considering how ecosystem functions are changed when biota is impaired. However, there is still limited empirical evidence from natural environments evaluating the direct and indirect (i.e. via biota effects of disturbance on ecosystem functioning. Oxygen deficiency is a widespread threat to coastal and estuarine communities. While the negative impacts of hypoxia on benthic communities are well known, few studies have assessed in situ how benthic communities subjected to different degrees of hypoxic stress alter their contribution to ecosystem functioning. We studied changes in sediment ecosystem function (i.e. oxygen and nutrient fluxes across the sediment water-interface by artificially inducing hypoxia of different durations (0, 3, 7 and 48 days in a subtidal sandy habitat. Benthic chamber incubations were used for measuring responses in sediment oxygen and nutrient fluxes. Changes in benthic species richness, structure and traits were quantified, while stress-induced behavioral changes were documented by observing bivalve reburial rates. The initial change in faunal behavior was followed by non-linear degradation in benthic parameters (abundance, biomass, bioturbation potential, gradually impairing the structural and functional composition of the benthic community. In terms of ecosystem function, the increasing duration of hypoxia altered sediment oxygen consumption and enhanced sediment effluxes of NH(4(+ and dissolved Si. Although effluxes of PO(4(3- were not altered significantly, changes were observed in sediment PO(4(3- sorption capability. The duration of hypoxia (i.e. number of days of stress explained a minor part of the changes in ecosystem function. Instead, the benthic community and disturbance-driven changes within the benthos explained a larger proportion of the variability in sediment oxygen- and nutrient fluxes. Our results emphasize that the level of stress to the

  12. Invertebrate response to nutrient-driven epiphytic load increase in Posidonia oceanica meadows

    Science.gov (United States)

    Castejón-Silvo, Inés; Domínguez, Marta; Terrados, Jorge; Tomas, Fiona; Morales-Nin, Beatriz

    2012-10-01

    Nutrient increases in coastal systems are becoming a world-wide concern since they promote strong structural and functional changes in shallow ecosystems. Increased nutrient availability in the water column may strongly enhance the leaf epiphytic communities of key habitat-forming species such as seagrasses through a bottom-up mechanism, competing for light and nutrients with the leaves. Epiphytes support an abundant and diverse community of resident invertebrates which fuel higher trophic levels in Posidonia oceanica food webs. We evaluated the response of seagrass, epiphytes and the invertebrate community to an experimental increase of water column nutrient availability. Nutrient increase was followed by a rise of epiphyte biomass. The increase in epiphytic biomass promoted invertebrate abundance, but appeared to have negative effects on P. oceanica shoot size. On the other hand, the increase in invertebrate abundance did not seem to control epiphytic biomass, which was not reversed to pre-nutrient enrichment levels. This work suggests that the abundance of invertebrate populations is limited by epiphyte biomass, through food or habitat provision, in P. oceanica systems and points to nutrients as the main driver of epiphyte biomass during summer. The results illustrate the control mechanisms at community level in P. oceanica meadows and the possible responses of a threatened ecosystem to human impact such as eutrophication.

  13. Spatial avoidance of patches of polluted chernozem soils by soil invertebrates

    Institute of Scientific and Technical Information of China (English)

    Konstantin B.Gongalsky; Svetlana A.Belorustseva; Daria M.Kuznetsova; Alexander V Matyukhin; Lyubov A.Pelgunova; Fyodor A.Savin; Alexander S.Shapovalov

    2009-01-01

    Soil invertebrates and heavy metal concentrations are heterogeneously distrib-uted in the soil of steppe plots surrounding an iron mining enterprise in southern Russia.This study assesses whether patches of high soil invertebrate abundance coincide with patches of low concentrations of pollutants.For this aim.spatial analysis by distance indices(SADIE)was applied.Three valleys in Belogorye Nature Reserve were chosen.One valley faced the tailing pond to the north and the other two faced south-east or South-west.Two sampling plots were chosen in each valley,60 m apart from each other.One very plot 16 soil corcs were collected from a grid of 4×4 units with a 5-m distance between each sample unit.Each Soil core had an area of 76cm2 and was 12-15 cnldeep.All macroinvertebrates were hand-sorted-and identified to family.Abundance of Soil invertebrates was not controlled by patches of rectal concentration in the soil.Epigaeic groups.like insects and other invertebrates inhabiting the litter layer.were not directly associated with local parameters of the soil.On the contrary.belowground invertebrate abundance(elaterid larvae and earthworms)showed significant dissociation with some heavy metal(Fe,Pb,Zn)concentrations in the soil.The patchiness of soil pollution may act as a leading factor of belowground soilinvertebrate distribution.The spatial structure of animal populations in industrially transformed soils needs further research.

  14. Interactions among contaminants and nutritional lipids during mobilization by digestive fluids of marine invertebrates.

    Science.gov (United States)

    Voparil, Ian M; Mayer, Lawrence M; Place, Allen R

    2003-07-15

    Coastal sediments contain complex mixtures of hydrophobic compounds including organic contaminants such as polycyclic aromatic hydrocarbons and biogenic compounds such as cholesterol and phospholipids. Within the guts of benthic invertebrates, these mixtures are subjected to digestive, chemical conditions that can be rich in surfactants and proteinaceous material. Using in vitro incubations as proxy for digestive exposure, we studied the solubilization of binary mixtures of nutritional and contaminant lipids into artificial seawater and six marine invertebrate gut fluids (Molpadia intermedia, Cucumaria frondosa, Arenicola marina, Arenicola brasiliensis, Parastichopus californicus, and Nereis virens). For animals with surfactant micelles or high protein concentrations, solubilization interactions were frequent. For example, in Arenicola marina gut fluid, benzo(a)pyrene enhanced the solubilization of hexadecane (491% of the compound alone) and palmitic acid (130%) but hindered cholesterol (83%). Benzo(a)pyrene concentrations increased in gut fluids in the presence of cholesterol (137% of BaP alone), phenanthrene (154%), lecithin (140%), and hexadecanol (232%). In A. marina gut fluid, dilution with seawater indicated that these enhancements occur only when micelles are present. Sediment-water partitioning models, used to predict the bioavailability of hydrophobic organic chemicals, do not account for such interactions between solubilizates (compounds solubilized in micelles). However, for animals exposed via a digestive tract containing micelles or high protein concentrations, digestive bioavailability and perhaps bioaccumulation are likely influenced by these interactions. PMID:12901659

  15. Proteomics insights: proteins related to larval attachment and metamorphosis of marine invertebrates

    KAUST Repository

    Chandramouli, Kondethimmanahalli

    2014-10-31

    The transition in an animal from a pelagic larval stage to a sessile benthic juvenile typically requires major morphological and behavioral changes. Larval competency, attachment and initiation of metamorphosis are thought to be regulated by intrinsic chemical signals and specific sets of proteins. However, the molecular mechanisms that regulate larval attachment and metamorphosis in marine invertebrates have yet to be fully elucidated. Despite the many challenges associated with analysis of the larvae proteome, recent proteomic technologies have been used to address specific questions in larval developmental biology. These and other molecular studies have generated substantial amount of information of the proteins and molecular pathways involved in larval attachment and metamorphosis. Furthermore, the results of these studies have shown that systematic changes in protein expression patterns and post-translational modifications (PTMs) are crucial for the transition from larva to juvenile. The degeneration of larval tissues is mediated by protein degradation, while the development of juvenile organs may require PTM. In terms of application, the identified proteins may serve as targets for antifouling compounds, and biomarkers for environmental stressors. In this review we highlight the strengths and limitations of proteomic tools in the context of the study of marine invertebrate larval biology.

  16. Ural River benthic communities response on the chemical spill

    International Nuclear Information System (INIS)

    The Ural River is the second river of the North Caspian basin, on the north-west border of the Kazakhstan and Russian. The middle flow of the Ural River is limited by the dam of Iriklin water reservoirs (about 80 km up from Orsk town, Orenburg district) to the mouth of Barbastay River (about 45 km down from Ural'sk town). On 13--17 November 1991, after an industrial incident in Orsk oil refinery enterprise effluent polluted the Ural River. An assessment of the Middle flow Ural River benthic communities by oil and phenols spill response is described. The paper is based on a study of the short-term response of benthic biocenosises compared with natural transformation of the community structure before pollution

  17. Anchor ice and benthic disturbance in shallow Antarctic waters: interspecific variation in initiation and propagation of ice crystals.

    Science.gov (United States)

    Denny, Mark; Dorgan, Kelly M; Evangelista, Dennis; Hettinger, Annaliese; Leichter, James; Ruder, Warren C; Tuval, Idan

    2011-10-01

    Sea ice typically forms at the ocean's surface, but given a source of supercooled water, an unusual form of ice--anchor ice--can grow on objects in the water column or at the seafloor. For several decades, ecologists have considered anchor ice to be an important agent of disturbance in the shallow-water benthic communities of McMurdo Sound, Antarctica, and potentially elsewhere in polar seas. Divers have documented anchor ice in the McMurdo communities, and its presence coincides with reduced abundance of the sponge Homaxinella balfourensis, which provides habitat for a diverse assemblage of benthic organisms. However, the mechanism of this disturbance has not been explored. Here we show interspecific differences in anchor-ice formation and propagation characteristics for Antarctic benthic organisms. The sponges H. balfourensis and Suberites caminatus show increased incidence of formation and accelerated spread of ice crystals compared to urchins and sea stars. Anchor ice also forms readily on sediments, from which it can grow and adhere to organisms. Our results are consistent with, and provide a potential first step toward, an explanation for disturbance patterns observed in shallow polar benthic communities. Interspecific differences in ice formation raise questions about how surface tissue characteristics such as surface area, rugosity, and mucus coating affect ice formation on invertebrates. PMID:22042434

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

    International Nuclear Information System (INIS)

    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)

  19. Aluminium impact on freshwater invertebrates at low pH: A review

    Science.gov (United States)

    Herrmann, Jan

    The state of knowledge on aluminium (Al) impact on freshwater invertebrates at low pH is reviewed. Mainly inorganic ions seem to be biologically harmful. Published effect/mechanism descriptions may seem somewhat contradictory, but this can be due to the heterogeneity of "the invertebrate group", as well as the multitude and complexity of occurring Al species, thereby also Al analysis problems. Addition of Al to streams has in some cases increased drift and death of mainly some "surface-dependent" species (chironomids, mayflies, dance flies, dixid midges), but also some strictly benthic animals (isopods, stoneflies), while other studies on a variety of animals do not record any change in neither drift, mortality nor biomass. In laboratory exposures Al has been shown to cause raised mortality for some daphnids and blackfly larvae at pH around 5; in the latter animals the effect was however mitigated by humus. A variety of other freshwater invertebrates were not affected. Moreover, at pH 4, Al has even been shown to improve the survival of mayfly nymphs and daphnids, otherwise impaired by the low pH in itself. The reason for this is not clear. Proofs for "food chain accumulation" of Al are still weak. Very high additions of Al have caused a decreased respiration rate in a dragonfly nymph, while a more field-relevant exposure level increased respiration in mayfly nymphs. This suggests a stress situation, probably due to impaired osmoregulation, indicating chemical or mechanical Al impact. The lowered oxygen uptake is then compensated for by improved respiration rate. A model for this is presented. Studies on crayfish, daphnids, mayflies and waterbugs indicate that Al can lower osmoregulatory efficiency and thereby affect the ion balance maintaining mechanisms of the animals. Such sublethal effects are important and should be studied further. The review also critically discusses the concepts mortality and bioavailability.

  20. Can UV radiation affect benthic deposit-feeders through biochemical alteration of food resources? An experimental study with juveniles of the benthic polychaete Eupolymnia nebulosa.

    Science.gov (United States)

    Nahon, Sarah; Pruski, Audrey M; Duchêne, Jean-Claude; Méjanelle, Laurence; Vétion, Gilles; Desmalades, Martin; Charles, François

    2011-05-01

    The growth, tentacle development and feeding activity of the benthic polychaete Eupolymnia nebulosa were examined to determine whether UV might affect marine deposit-feeders indirectly through the modification of the nutritional quality of their resources. Since marine invertebrates have higher nutritional requirements during the period following settlement, we tested the effect of UV-altered phytodetritus on freshly settled juveniles of E. nebulosa. Phytodetritus was prepared from cultures of the diatom Skeletonema costatum either grown under or sheltered from UVB radiation. Sterol content of phytodetritus was unmodified by UV radiation. Conversely, phytodetritus was noticeably depleted in polyunsaturated fatty acids. Growth and tentacle development of juveniles fed on altered phytodetritus were reduced by 35% and 15% respectively, suggesting potential deficiencies in essential nutrients. In response to the lower quality of the phytodetritus, juveniles explored a wider area as they search for food, a strategy that could compensate for low food quality. PMID:21388674

  1. 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.

  2. Trophic interactions among invertebrates in termitaria in the African savanna : a stable isotope approach

    NARCIS (Netherlands)

    De Visser, Sarah N.; Freymann, Bernd P.; Schnyder, Hans

    2008-01-01

    1. Termites (Isoptera) in tropical savannas are known as ecosystem engineers, affecting the spatial and temporal distribution of water, carbon, cations, and nutrients through their mound structures. Their mounds, however, also offer habitation to diverse taxa and feeding guilds of other invertebrate

  3. Body size-based trophic structure of a deep marine ecosystem.

    Science.gov (United States)

    Romero-Romero, Sonia; Molina-Ramírez, Axayacatl; Hofer, Juan; Luis Acuña, José

    2016-01-01

    Nitrogen stable isotope ratios (δ15N) and body size were used to describe the size-based trophic structure of a deep-sea ecosystem, the Avilés submarine Canyon (Cantabrian Sea, Southern Bay of Biscay). We analyzed δ15N of specimens collected on a seasonal basis (March 2012, October 2012, and May 2013), from a variety of zones (benthic, pelagic), taxa (from zooplankton through invertebrates and fishes to giant squids and cetaceans), or depths (from surface to 4700 m) that spanned nine orders of magnitude in body mass. Our data reveal a strong linear dependence of trophic level on body size when data were considered either individually, aggregated into taxonomical categories, or binned into size classes. The three approaches render similar results that were not significantly different and yielded predator:prey body mass ratios (PPMR) of 1156:1, 3792:1 and 2718:1, respectively. Thus, our data represent unequivocal evidence of interspecific, size-based trophic structure of a whole ecosystem based on taxonomic/functional categories. We studied the variability in δ15N not explained by body mass (W) using linear mixed modeling and found that the δ15N vs. log10 W relationship holds for both pelagic and benthic systems, with benthic organisms isotopically enriched relative to pelagic organisms of the same size. However there is a marked seasonal variation potentially related to the recycling state of the system. PMID:27008786

  4. Predicting species cover of marine macrophyte and invertebrate species combining hyperspectral remote sensing, machine learning and regression techniques.

    Directory of Open Access Journals (Sweden)

    Jonne Kotta

    Full Text Available In order to understand biotic patterns and their changes in nature there is an obvious need for high-quality seamless measurements of such patterns. If remote sensing methods have been applied with reasonable success in terrestrial environment, their use in aquatic ecosystems still remained challenging. In the present study we combined hyperspectral remote sensing and boosted regression tree modelling (BTR, an ensemble method for statistical techniques and machine learning, in order to test their applicability in predicting macrophyte and invertebrate species cover in the optically complex seawater of the Baltic Sea. The BRT technique combined with remote sensing and traditional spatial modelling succeeded in identifying, constructing and testing functionality of abiotic environmental predictors on the coverage of benthic macrophyte and invertebrate species. Our models easily predicted a large quantity of macrophyte and invertebrate species cover and recaptured multitude of interactions between environment and biota indicating a strong potential of the method in the modelling of aquatic species in the large variety of ecosystems.

  5. Spatial Variability of Benthic-Pelagic Coupling in an Estuary Ecosystem: Consequences for Microphytobenthos Resuspension Phenomenon

    Science.gov (United States)

    Ubertini, Martin; Lefebvre, Sébastien; Gangnery, Aline; Grangeré, Karine; Le Gendre, Romain; Orvain, Francis

    2012-01-01

    The high degree of physical factors in intertidal estuarine ecosystem increases material processing between benthic and pelagic compartments. In these ecosystems, microphytobenthos resuspension is a major phenomenon since its contribution to higher trophic levels can be highly significant. Understanding the sediment and associated microphytobenthos resuspension and its fate in the water column is indispensable for measuring the food available to benthic and pelagic food webs. To identify and hierarchize the physical/biological factors potentially involved in MPB resuspension, the entire intertidal area and surrounding water column of an estuarine ecosystem, the Bay des Veys, was sampled during ebb tide. A wide range of physical parameters (hydrodynamic regime, grain size of the sediment, and suspended matter) and biological parameters (flora and fauna assemblages, chlorophyll) were analyzed to characterize benthic-pelagic coupling at the bay scale. Samples were collected in two contrasted periods, spring and late summer, to assess the impact of forcing variables on benthic-pelagic coupling. A mapping approach using kriging interpolation enabled us to overlay benthic and pelagic maps of physical and biological variables, for both hydrological conditions and trophic indicators. Pelagic Chl a concentration was the best predictor explaining the suspension-feeders spatial distribution. Our results also suggest a perennial spatio-temporal structure of both benthic and pelagic compartments in the ecosystem, at least when the system is not imposed to intense wind, with MPB distribution controlled by both grain size and bathymetry. The benthic component appeared to control the pelagic one via resuspension phenomena at the scale of the bay. Co-inertia analysis showed closer benthic-pelagic coupling between the variables in spring. The higher MPB biomass observed in summer suggests a higher contribution to filter-feeders diets, indicating a higher resuspension effect in

  6. Transfer of radiocaesium from contaminated bottom sediments to marine organisms through benthic food chains in post-Fukushima and post-Chernobyl periods

    Science.gov (United States)

    Bezhenar, Roman; Jung, Kyung Tae; Maderich, Vladimir; Willemsen, Stefan; de With, Govert; Qiao, Fangli

    2016-05-01

    After the earthquake and tsunami on 11 March 2011 damaged the Fukushima Dai-ichi Nuclear Power Plant (FDNPP), an accidental release of a large amount of radioactive isotopes into both the air and the ocean occurred. Measurements provided by the Japanese agencies over the past 5 years show that elevated concentrations of 137Cs still remain in sediments, benthic organisms, and demersal fishes in the coastal zone around the FDNPP. These observations indicate that there are 137Cs transfer pathways from bottom sediments to the marine organisms. To describe the transfer quantitatively, the dynamic food chain biological uptake model of radionuclides (BURN) has been extended to include benthic marine organisms. The extended model takes into account both pelagic and benthic marine organisms grouped into several classes based on their trophic level and type of species: phytoplankton, zooplankton, and fishes (two types: piscivorous and non-piscivorous) for the pelagic food chain; deposit-feeding invertebrates, demersal fishes fed by benthic invertebrates, and bottom omnivorous predators for the benthic food chain; crustaceans, mollusks, and coastal predators feeding on both pelagic and benthic organisms. Bottom invertebrates ingest organic parts of bottom sediments with adsorbed radionuclides which then migrate up through the food chain. All organisms take radionuclides directly from water as well as food. The model was implemented into the compartment model POSEIDON-R and applied to the north-western Pacific for the period of 1945-2010, and then for the period of 2011-2020 to assess the radiological consequences of 137Cs released due to the FDNPP accident. The model simulations for activity concentrations of 137Cs in both pelagic and benthic organisms in the coastal area around the FDNPP agree well with measurements for the period of 2011-2015. The decrease constant in the fitted exponential function of simulated concentration for the deposit-feeding invertebrates (0.45 yr-1

  7. Benthic habitat data of Wawaloi and Keei, Kona Coast, Island of Hawaii, August 2004 (NODC Accession 0070530)

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — Transects were made at two locations on the west side of the Island of Hawaii in August 2004 to study the structure and composition of the benthic habitat....

  8. 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

  9. Physiology of invertebrate oxytocin and vasopressin neuropeptides

    OpenAIRE

    Gruber, Christian W.

    2013-01-01

    New findings • What is the topic of this review? This article describes the discovery and function of invertebrate oxytocin and vasopressin neuropeptides. • What advances does it highlight? The novel discovery of oxytocin-like peptides in arthropods is described. An up-to date overview is gven of the functional role (physiology and behaviour) of oxytocin and vasopressin signalling. The application of natural peptides for drug development is discussed. Neuropeptides and regulatory peptide horm...

  10. Pesticides reduce regional biodiversity of stream invertebrates

    OpenAIRE

    Beketov, Mikhail A.; Kefford, Ben J.; Schäfer, Ralf B.; Liess, Matthias

    2013-01-01

    The biodiversity crisis is one of the greatest challenges facing humanity, but our understanding of the drivers remains limited. Thus, after decades of studies and regulation efforts, it remains unknown whether to what degree and at what concentrations modern agricultural pesticides cause regional-scale species losses. We analyzed the effects of pesticides on the regional taxa richness of stream invertebrates in Europe (Germany and France) and Australia (southern Victoria). Pesticides caused ...

  11. The isochore patterns of invertebrate genomes

    Directory of Open Access Journals (Sweden)

    Costantini Maria

    2009-11-01

    Full Text Available Abstract Background Previous investigations from our laboratory were largely focused on the genome organization of vertebrates. We showed that these genomes are mosaics of isochores, megabase-size DNA sequences that are fairly homogeneous in base composition yet belong to a small number of families that cover a wide compositional spectrum. A question raised by these results concerned how far back in evolution an isochore organization of the eukaryotic genome arose. Results The present investigation deals with the compositional patterns of the invertebrates for which full genome sequences, or at least scaffolds, are available. We found that (i a mosaic of isochores is the long-range organization of all the genomes that we investigated; (ii the isochore families from the invertebrate genomes matched the corresponding families of vertebrates in GC levels; (iii the relative amounts of isochore families were remarkably different for different genomes, except for those from phylogenetically close species, such as the Drosophilids. Conclusion This work demonstrates not only that an isochore organization is present in all metazoan genomes analyzed that included Nematodes, Arthropods among Protostomia, Echinoderms and Chordates among Deuterostomia, but also that the isochore families of invertebrates share GC levels with the corresponding families of vertebrates.

  12. Oxygen penetration through invertebrate burrow walls in Korean tidal flat

    Science.gov (United States)

    Koo, Bon Joo; Koh, Chul-Hwan

    2013-12-01

    Macrofaunal burrows increase the surface area of the sediment-water interface, which has a great impact on the metabolism of aerobic microbes and the oscillation of reduced metabolites within the sediment. Given the importance of macrofauna in surficial sediments, the aim of this study is to examine the effects of burrow architectures on dissolved oxygen diffusion rates in comparison with unburrowed sediment, and thereby to evaluate the theoretical assumption used for modeling solute distribution in the burrow system using field samples. Employing microsensors, horizontal oxygen profiles were measured on a micrometer scale around burrows of seven invertebrates in tidal flats of the west coast of Korea. Oxygen diffusion distance through the burrow walls of seven invertebrates showed spatio-temporal variation with a range of 0.6 to 2.9 mm. Two groups of burrows were identified based on their oxygen diffusive properties relative to unburrowed sediments: 1) oxygen penetration similar to that of ambient sediments and 2) clearly enhanced oxygen penetration. Differences in the diffusive properties of the burrow wall were related to the burrow depth and diameter, existence of mucus lining on the wall, sediment grain size, and tidal phases. Also inhabitant activity was an important factor affecting oxygen penetration, which is discussed in the paper. These results further demonstrate that simplified assumptions (i.e. burrow structures are viewed as direct biogeochemical extensions of the sediment-water interface) may not be exact representation of the nature.

  13. Effects of copper on invertebrate-sediment interactions.

    Science.gov (United States)

    Hunting, E R; Mulder, C; Kraak, M H S; Breure, A M; Admiraal, W

    2013-09-01

    Toxicants potentially decouple links between biodiversity and ecosystem processes. This study aimed to evaluate how toxicants affect invertebrate bioturbation and decomposition. Effects of copper on functionally distinct macrofaunal species (Asellus aquaticus and Tubifex spp.), decomposition (release of dissolved organic carbon, DOC) and Average Metabolic Response (AMR) and Community Metabolic Diversity (CMD) of bacteria were determined in 5-day microcosm experiments. Bioturbation was assessed as sediment redox potential (Eh) profiles. Concentration-response curves of the functional parameters DOC, and the faunal mediated AMR and CMD in the presence of Tubifex spp. depended on Tubifex spp. survival, i.e. similar EC50 values for both endpoints. In contrast, functional parameters in the presence of A. aquaticus were more sensitive than survival. Sediment Eh-profiles showed that reduced decomposition was caused by reduced sediment reworking by A. aquaticus at sub-lethal copper concentrations. These observations hint at a decoupling of invertebrate community structure and ecosystem functioning upon stress. PMID:23747821

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

    Directory of Open Access Journals (Sweden)

    Ludwig Buckup

    2007-06-01

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

  15. Benthic Habitats of the Florida Keys

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — The benthic habitats of the Florida Keys were mapped from a series of 450 aerial photographs. Ecologists outlined the boundaries of specific habitat types by...

  16. BENTHIC MACROFAUNAL ALIENS IN WILLAPA BAY

    Science.gov (United States)

    Benthic macrofaunal samples were collected at random stations in Willapa Bay, WA, in four habitats [eelgrass (Zostera marina), Atlantic cordgrass (Spartina alterniflora), mud shrimp (Upogebia pugettensis), ghost shrimp (Neotrypaea californiensis)] in 1996 and in seven habitats (Z...

  17. Feasibility of remote sensing benthic microalgae

    Science.gov (United States)

    Zingmark, R. G.

    1979-01-01

    Results of data analyses from multispectral scanning data are presented. The data was collected in July 1977 for concentration of chlorophyll in benthic microalgae (mainly diatoms) on an estuary mudflat.

  18. Responses of litter invertebrate communities to litter manipulation in a Japanese conifer plantation

    Science.gov (United States)

    Yoshida, Tomohiro; Takito, Yuki; Soga, Masashi; Hijii, Naoki

    2013-08-01

    We examined how the litter invertebrate communities were affected by the temporal changes in the mass and structural complexity of the litter resources by adding and removing litter on the forest floor of a temperate conifer plantation (Cryptomeria japonica) in Japan. We showed that litter mass and depth in the litter-addition (L+) plots changed rapidly into a steady-state condition similar to those in the control plots, mainly due to accelerated decomposition processes during the rainy season. Higher area-based densities of litter invertebrates in the L+ plots, similar mass-based densities between the L+ and control plots, and significant positive correlations between litter mass and the number of individuals implied that the abundance of litter invertebrates would be governed by litter mass rather than by the litter depth. Many litter invertebrates including detritivores were collected even in the litter-removal (L-) area. The relative abundances of invertebrate predators collecting pitfall traps were higher in the L- plots and lower in the L+ plots compared to those in the control plots, whereas those collecting Tullgren funnels were higher in the L+ plots than in the control plots. In the L+ plots, the range of variation in the community compositions among the samples decreased significantly over time in response to a drastic decrease in litter mass, in contrast to the control plots, which showed a relatively constant community composition during the study period. Our litter manipulation experiment reveals some of the mechanisms responsible for maintaining an equilibrium state of forest-floor litter mass and for the responses of litter invertebrate communities to temporal changes in the litter.

  19. Seasonal variation in species composition and abundance of demersal fish and invertebrates in a Seagrass Natural Reserve on the eastern coast of the Shandong Peninsula, China

    Science.gov (United States)

    Xu, Qiang; Guo, Dong; Zhang, Peidong; Zhang, Xiumei; Li, Wentao; Wu, Zhongxin

    2016-03-01

    Seagrass habitats are structurally complex ecosystems, which support high productivity and biodiversity. In temperate systems the density of seagrass may change seasonally, and this may influence the associated fish and invertebrate community. Little is known about the role of seagrass beds as possible nursery areas for fish and invertebrates in China. To study the functioning of a seagrass habitat in northern China, demersal fish and invertebrates were collected monthly using traps, from February 2009 to January 2010. The density, leaf length and biomass of the dominant seagrass Zostera marina and water temperature were also measured. The study was conducted in a Seagrass Natural Reserve (SNR) on the eastern coast of the Shandong Peninsula, China. A total of 22 fish species and five invertebrate species were recorded over the year. The dominant fish species were Synechogobius ommaturus, Sebastes schlegelii, Pholis fangi, Pagrus major and Hexagrammos otakii and these species accounted for 87% of the total number of fish. The dominant invertebrate species were Charybdis japonica and Octopus variabilis and these accounted for 98% of the total abundance of invertebrates. There was high temporal variation in species composition and abundance. The peak number of fish species occurred in August-October 2009, while the number of individual fish and biomass was highest during November 2009. Invertebrate numbers and biomass was highest in March, April, July and September 2009. Temporal changes in species abundance of fishes and invertebrates corresponded with changes in the shoot density and leaf length of the seagrass, Zostera marina.

  20. Effects of simulated eutrophication and overfishing on algae and invertebrate settlement in a coral reef of Koh Phangan, Gulf of Thailand.

    Science.gov (United States)

    Stuhldreier, Ines; Bastian, Pepe; Schönig, Eike; Wild, Christian

    2015-03-15

    Coral reefs in the Gulf of Thailand are highly under-investigated regarding responses to anthropogenic stressors. Thus, this study simulated overfishing and eutrophication using herbivore exclosure cages and slow-release fertilizer to study the in-situ effects on benthic algae and invertebrate settlement in a coral reef of Koh Phangan, Thailand. Settlement of organisms and the development of organic matter on light-exposed and shaded tiles were quantified weekly/biweekly over a study period of 12 weeks. Simulated eutrophication did not significantly influence response parameters, while simulated overfishing positively affected dry mass, turf algae height and fleshy macroalgae occurrence on light-exposed tiles. On shaded tiles, settlement of crustose coralline algae decreased, while abundances of ascidians increased compared to controls. An interactive effect of both stressors was not observed. These results hint to herbivory as actual key controlling factor on the benthic community, and fleshy macroalgae together with ascidians as potential bioindicators for local overfishing. PMID:25649838

  1. Fossil invertebrates records in cave sediments and paleoenvironmental assessments - a study of four cave sites from Romanian Carpathians

    Science.gov (United States)

    Moldovan, O. T.; Constantin, S.; Panaiotu, C.; Roban, R. D.; Frenzel, P.; Miko, L.

    2016-01-01

    Fossil invertebrates from cave sediments have been recently described as a potential new proxy for paleoenvironment and used in cross-correlations with alternate proxy records from cave deposits. Here we present the results of a fossil invertebrates study in four caves from two climatically different regions of the Romanian Carpathians, to complement paleoenvironmental data previously reported. Oribatid mites and ostracods are the most common invertebrates in the studied cave sediments. Some of the identified taxa are new to science, and most of them are indicative for either warm and/or cold stages or dry and/or wetter oscillations. In two caves the fossil invertebrates records indicate rapid climate oscillations during times known for a relatively stable climate. By corroborating the fossil invertebrates' record with the information given by magnetic properties and sediment structures, complementary data on past vegetation, temperatures and hydraulic regimes could be gathered. This paper analyzes the potential of fossil invertebrate records as a paleoenvironmental proxy, potential problems and pitfalls.

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

    DEFF Research Database (Denmark)

    Christensen, Sarah Christine

    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......Few if any drinking water distribution systems worldwide are completely free of invertebrate animals and presumably it has been that way since the very first distribution system was constructed. Invertebrates visible to the naked eye cause consumer complaints and are considered a sign of bad...... 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...

  3. A Vulnerability Assessment of Fish and Invertebrates to Climate Change on the Northeast U.S. Continental Shelf.

    Directory of Open Access Journals (Sweden)

    Jonathan A Hare

    Full Text Available Climate change and decadal variability are impacting marine fish and invertebrate species worldwide and these impacts will continue for the foreseeable future. Quantitative approaches have been developed to examine climate impacts on productivity, abundance, and distribution of various marine fish and invertebrate species. However, it is difficult to apply these approaches to large numbers of species owing to the lack of mechanistic understanding sufficient for quantitative analyses, as well as the lack of scientific infrastructure to support these more detailed studies. Vulnerability assessments provide a framework for evaluating climate impacts over a broad range of species with existing information. These methods combine the exposure of a species to a stressor (climate change and decadal variability and the sensitivity of species to the stressor. These two components are then combined to estimate an overall vulnerability. Quantitative data are used when available, but qualitative information and expert opinion are used when quantitative data is lacking. Here we conduct a climate vulnerability assessment on 82 fish and invertebrate species in the Northeast U.S. Shelf including exploited, forage, and protected species. We define climate vulnerability as the extent to which abundance or productivity of a species in the region could be impacted by climate change and decadal variability. We find that the overall climate vulnerability is high to very high for approximately half the species assessed; diadromous and benthic invertebrate species exhibit the greatest vulnerability. In addition, the majority of species included in the assessment have a high potential for a change in distribution in response to projected changes in climate. Negative effects of climate change are expected for approximately half of the species assessed, but some species are expected to be positively affected (e.g., increase in productivity or move into the region. These

  4. Marine invertebrate diversity in Aristotle’s zoology

    OpenAIRE

    Voultsiadou, E.; D. VAFIDIS

    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 related to animals currently classified as marine invertebrates. These records corresponded to 94 different animal names or descriptive phrases which were assigned to 85 current marine invertebrate ...

  5. Invertebrates in testing of environmental chemicals: are they alternatives?

    OpenAIRE

    Lagadic, L.; Caquet, T.

    1998-01-01

    An enlarged interpretation of alternatives in toxicology testing includes the replacement of one animal species with another, preferably a nonmammalian species. This paper reviews the potential of invertebrates in testing environmental chemicals and provides evidence of their usefulness in alternative testing methodologies. The first part of this review addresses the use of invertebrates in laboratory toxicology testing. Problems in extrapolating results obtained in invertebrates to those obt...

  6. Phenotypic plasticity and morphological integration in a marine modular invertebrate

    Directory of Open Access Journals (Sweden)

    Manrique Nelson

    2007-07-01

    Full Text Available Abstract Background Colonial invertebrates such as corals exhibit nested levels of modularity, imposing a challenge to the depiction of their morphological evolution. Comparisons among diverse Caribbean gorgonian corals suggest decoupling of evolution at the polyp vs. branch/internode levels. Thus, evolutionary change in polyp form or size (the colonial module sensu stricto does not imply a change in colony form (constructed of modular branches and other emergent features. This study examined the patterns of morphological integration at the intraspecific level. Pseudopterogorgia bipinnata (Verrill (Octocorallia: Gorgoniidae is a Caribbean shallow water gorgonian that can colonize most reef habitats (shallow/exposed vs. deep/protected; 1–45 m and shows great morphological variation. Results To characterize the genotype/environment relationship and phenotypic plasticity in P. bipinnata, two microsatellite loci, mitochondrial (MSH1 and nuclear (ITS DNA sequences, and (ITS2 DGGE banding patterns were initially compared among the populations present in the coral reefs of Belize (Carrie Bow Cay, Panama (Bocas del Toro, Colombia (Cartagena and the Bahamas (San Salvador. Despite the large and discrete differentiation of morphotypes, there was no concordant genetic variation (DGGE banding patterns in the ITS2 genotypes from Belize, Panama and Colombia. ITS1–5.8S-ITS2 phylogenetic analysis afforded evidence for considering the species P. kallos (Bielschowsky as the shallow-most morphotype of P. bipinnata from exposed environments. The population from Carrie Bow Cay, Belize (1–45 m was examined to determine the phenotypic integration of modular features such as branch thickness, polyp aperture, inter-polyp distance, internode length and branch length. Third-order partial correlation coefficients suggested significant integration between polypar and colonial traits. Some features did not change at all despite 10-fold differences in other integrated

  7. 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)

  8. Acute toxicity of four heavy metals to benthic fish food organisms from the River Khan, Ujjain

    Energy Technology Data Exchange (ETDEWEB)

    Qureshi, S.A.; Saksena, A.B.; Singh, V.P.

    1980-01-01

    The acute toxicity of four heavy metals (Hg, Zn, Cd and Pb) to two benthic invertebrates viz. Tubifex tubifex and 4th instar larvae of chironomous sp. from the River Khan (Ujjain) have been determined by static bioassay experiments. Although both Tubifex tubifex and chironomous larvae have been found to be resistant to heavy metals (Hg, Zn, Cd and Pb), the experiments led to an observation that chironomous larvae are comparatively less tolerant than Tubifex tubifex. However, when the individual toxicity of heavy metals is considered it seems that the toxicity of metals is in the following order viz. Hg>Zn>Cd>Pb. The investigations reveal variation in the sensitivity of different organisms to the same toxicant and the same organisms to different toxicants.

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

    Science.gov (United States)

    Sell, Anne F.; Kröncke, Ingrid

    2013-07-01

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

  10. 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.

  11. The Dicistroviridae: An Emerging Family of Invertebrate Viruses

    Institute of Scientific and Technical Information of China (English)

    Bryony C. Bonning

    2009-01-01

    Dicistroviruses comprise a newly characterized and rapidly expanding family of small RNA viruses of invertebrates. Several features of this virus group have attracted considerable research interest in recent years. In this review I provide an overview of the Dicistroviridae and describe progress made toward the understanding and practical application of dicistroviruses, including (i) construction of the first infectious clone of a dicistrovirus, (ii) use of the baculovirus expression system for production of an infectious dicistrovirus, (iii) the use of Drosophila C virus for analysis of host response to virus infection, and (iv) correlation of the presence of Israeli acute paralysis virus with honey bee colony collapse disorder. The potential use of dicistroviruses for insect pest management is also discussed. The structure, mechanism and practical use of the internal ribosome entry site (IRES) elements has recently been reviewed elsewhere.

  12. Surface-dependent strategies and energy flux in benthic marine communities or, why corals do not exist in the Mediterranean

    OpenAIRE

    Zabala i Limousin, Mikel; Ballesteros i Sagarra, Enric, 1958-

    1989-01-01

    Most structure-building organisms in rocky benthic communities are surface-dependent because their energy inputs depend mainly on the surface they expose to water. Two photosynthetic strategies, divided into calcareous and non calcareous algae, strict suspension-feeders and photosynthetic suspension feeders (e.g. hermatypic corals) are the four main strategies evolutively acquired by benthic organisms. Competition between those strategies occur in relation to productivity of the different spe...

  13. The role of histones in the immune responses of aquatic invertebrates

    Directory of Open Access Journals (Sweden)

    C Nikapitiya

    2013-10-01

    Full Text Available Histones are primary components of eukaryotic chromatin and highly abundant in all animal cells. In addition to their important role in chromatin structure and transcriptional regulation, histones contribute to innate immune responses. In several aquatic invertebrate species, as well as in many other invertebrate and vertebrate species, the transcripts for core histones are upregulated in response to immune challenge and exposure to environmental stressors. Histones show antimicrobial activity against bacteria and parasites in vitro and in vivo and have the ability to bind bacterial lipopolysaccharide and other pathogen-associated molecules. Several mechanisms regulating and facilitating the antimicrobial action of histones against pathogens have been described in vertebrate and some invertebrate species, including the production of Extracellular Traps (ETs and the accumulation of histones in lipid droplets that can be selectively released in response to immune stimuli. Further studies are needed to determine the mechanisms of action of histones in immune responses in aquatic invertebrates and investigate the potential use of histones in the treatment of infectious diseases in aquaculture

  14. Comparative and Evolutionary Analysis of the Interleukin 17 Gene Family in Invertebrates.

    Directory of Open Access Journals (Sweden)

    Xian-De Huang

    Full Text Available Interleukin 17 (IL-17 is an important pro-inflammatory cytokine and plays critical roles in the immune response to pathogens and in the pathogenesis of inflammatory and autoimmune diseases. Despite its important functions, the origin and evolution of IL-17 in animal phyla have not been characterized. As determined in this study, the distribution of the IL-17 family among 10 invertebrate species and 7 vertebrate species suggests that the IL-17 gene may have originated from Nematoda but is absent from Saccoglossus kowalevskii (Hemichordata and Insecta. Moreover, the gene number, protein length and domain number of IL-17 differ widely. A comparison of IL-17-containing domains and conserved motifs indicated somewhat low amino acid sequence similarity but high conservation at the motif level, although some motifs were lost in certain species. The third disulfide bond for the cystine knot fold is formed by two cysteine residues in invertebrates, but these have been replaced by two serine residues in Chordata and vertebrates. One third of invertebrate IL-17 proteins were found to have no predicted signal peptide. Furthermore, an analysis of phylogenetic trees and exon-intron structures indicated that the IL-17 family lacks conservation and displays high divergence. These results suggest that invertebrate IL-17 proteins have undergone complex differentiation and that their members may have developed novel functions during evolution.

  15. ECOLOGICAL ASPECTS OF BENTHIC COMMUNITIES FROM SOMESUL CALD CATCHMENT AREA

    Directory of Open Access Journals (Sweden)

    Karina Battes

    2001-01-01

    Full Text Available The present paper represents a preliminary study of periphyton and zoobenthos community from the Someşul Cald catchment area. Zoobenthos was sampled seasonally during 2000. Benthic community structure was similar at the five sampling sites. Thus, mayflies and chironomids recorded high numerical percentage abundances and densities. Oligochaetes, water mites and caddisflies were identified to species level. 38 Oligochaeta, 28 water mite and 12 caddis fly species were found in the sampling period. The samplings collected in the year 2001 included 80 algal species belonging to 5 phyla. Diatoms (Bacillariophyta dominated both qualitatively and quantitatively at all sampling sites.

  16. Status and variation of invertebrates in Lakes Albert and Kyoga

    OpenAIRE

    Ndawula, L.M.; Sekiranda, S.K.; Kiggundu, V.; Pabire Ghandi, W.

    2012-01-01

    Invertebrates are some of the key food items for fish diets. They thus form an important fish food environment upon which the fisheries thrives in terms of production through dietary support. Invertebrates communities of Lakes Albert and Kyoga have been evaluated and considered the implications for diets and production of commercial fishes.

  17. 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...

  18. 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.

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

    Science.gov (United States)

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

    2015-12-01

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

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

    Science.gov (United States)

    Dinçer, Feyza

    2016-02-01

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

  1. Community shelter use in response to two benthic decapod predators in the Long Island Sound.

    Science.gov (United States)

    Hudson, David M; Reagan, Dugan; Crivello, Joseph F

    2016-01-01

    To investigate community shelter effects of two invasive decapod species, Hemigrapsus sanguineus and Carcinus maenas, in the Long Island Sound (LIS), we deployed artificial shelters in the intertidal and immediate subtidal zones. These consisted of five groups during the summer: a control, a resident H. sanguineus male or female group, and a resident C. maenas male or female group. We quantified utilization of the shelters at 24 h by counting crabs and fish present. We found significant avoidance of H. sanguineus in the field by benthic hermit crabs (Pagurus spp.) and significant avoidance of C. maenas by the seaboard goby (Gobiosoma ginsburgi). The grubby (Myoxocephalus aenaeus) avoided neither treatment, probably since it tends to be a predator of invertebrates. H. sanguineus avoided C. maenas treatments, whereas C. maenas did not avoid any treatment. Seasonal deployments in the subtidal indicated cohabitation of a number of benthic species in the LIS, with peak shelter use corresponding with increased predation and likely reproductive activity in spring and summer for green crabs (C. maenas), hermit crabs (Pagurus spp.), seaboard gobies (G. ginsburgi), and grubbies (Myoxocephalus aenaeus). PMID:27547570

  2. Sensory basis for detection of benthic prey in two Lake Malawi cichlids.

    Science.gov (United States)

    Schwalbe, Margot A B; Webb, Jacqueline F

    2014-04-01

    The adaptive radiations of African cichlids resulted in a diversity of feeding morphologies and strategies, but the role of sensory biology in prey detection and feeding ecology remains largely unexplored. Two endemic Lake Malawi cichlid genera, Tramitichromis and Aulonocara, feed on benthic invertebrates, but differ in lateral line morphology (narrow and widened lateral line canals, respectively) and foraging strategy. The hypothesis that they use their lateral line systems differently was tested by looking at the relative contribution of the lateral line system and vision in prey detection by Tramitichromis sp. and comparing results to those from a complementary study using Aulonocara stuartgranti (Schwalbe et al., 2012). First, behavioral trials were used to assess the ability of Tramitichromis sp. to detect live (mobile) and dead (immobile) benthic prey under light and dark conditions. Second, trials were run before, immediately after, and several weeks after chemical ablation of the lateral line system to determine its role in feeding behavior. Results show that Tramitichromis sp. is a visual predator that neither locates prey in the dark nor depends on lateral line input for prey detection and is thus distinct from A. stuartgranti, which uses its lateral line or a combination of vision and lateral line to detect prey depending on light condition. Investigating how functionally distinctive differences in sensory morphology are correlated with feeding behavior in the laboratory and determining the role of sensory systems in feeding ecology will provide insights into how sensory capabilities may contribute to trophic niche segregation. PMID:24369759

  3. Dinoflagellate cysts and benthic foraminifera in surface sediments from the Mar Piccolo in Taranto (Ionian Sea, Southern Italy)

    Science.gov (United States)

    Ferraro, L.; Rubino, F.; Frontalini, F.; Belmonte, M.; Di Leo, A.; Giandomenico, S.; Greco, M.; Lirer, F.; Spada, L.; Vallefuoco, M.

    2012-12-01

    Coastal areas have traditionally been places of human settlement, with the increasing development of cities, industries and other human-related activities possibly having an impact on the aquatic ecosystem. These impacts may take the form of pollution from industrial, domestic, agricultural or mining activities. For this reason, attention to marine environmental problems has recently increased and the search for new methodologies and techniques for the monitoring of coastal-marine areas become more and more active and accurate. In this context biological indicators result a useful tool to provide indication of environmental conditions including the presence or absence of contaminants; in fact biological monitoring is more directly related to the ecological health of an ecosystem than are chemical data. The increasing importance of bioindicators is also encouraged within the European Union's Water Framework Directive (WFD), which aims to achieve a good ecological status in all European water bodies (i.e., rivers, lakes and coastal waters). Among the wide range of bioindicators, 5 biological elements are listed within the WFD: phytoplankton, macroalgae, angiosperms, benthic invertebrates and fishes. Benthic invertebrates as foraminifera represent a group of protozoa widely distributed in all brackish and marine environments which are used in studies assessing the environmental quality of areas subject to intense human activity. Moreover in coastal marine environments benthic and pelagic domain present several relationships, one of these is represented by the life cycles of phytoplankton species, as Dinoflagellates, which include the production of benthic stages (cysts). These dormant stages, which accumulate in confined marine muddy areas, such as ports, lagoons or estuaries, can reach high densities, similar to the seed banks of terrestrial plants. The cysts have a high preservation potential and can rest in/on the sediments for decades. Due to this peculiar

  4. 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

    from the sources. In conclusion, water temperature range was highly correlated with number of taxa, although other factors, such as substratum composition, stability and invertebrate drift, may also play an important role in the determination of longitudinal changes in invertebrate community composition and structure along spring-fed streams.

  5. The response of stream fish to local and reach-scale variation in the occurrence of a benthic aquatic macrophyte

    Science.gov (United States)

    Argentina, J.E.; Freeman, Mary C.; Freeman, B.J.

    2010-01-01

    The aquatic macrophyte Podostemum ceratophyllum has been shown to increase stream productivity, abundance and biomass of benthic invertebrates, and local occurrences of some stream fishes. However, experimental evidence that fishes preferentially associate with Podostemum is lacking, and the value of Podostemum as a predictor of stream fish assemblage composition has not been studied. We conducted two short-term (2 week), small-scale (36 m2) experimental manipulations of Podostemum cover in the Conasauga River (Georgia and Tennessee, U.S.), and found higher abundances of benthic insectivorous fishes in patches with augmented (>80%) compared to reduced (7%) Podostemum cover. In an observational study, we quantified associations among percent cover of Podostemum, fish species richness, land cover, shoal length and base-flow turbidity at 20 randomly selected shoals from a 39-km reach that spanned a gradient of decreasing forest land cover.Richness of all fish species and of lotic fishes peaked in the centre of the study reach, and richness was weakly correlated with predictor variables. Occupancy models for individual species also indicated that longitudinal position was a strong covariate for 13 of 19 species examined, with little support that Podostemum cover influenced occupancy. Local associations may reflect choices by benthic fishes to utilise Podostemum, whereas downstream decline in fish species richness and Podostemum cover may reflect altered capacity of the system to support native species. Published 2009. This article is a US Government work and is in the public domain in the USA.

  6. Channel Morphology and Hydraulics as Controls on Spatial Patterns of Invertebrate Drift in a Mountain Stream.

    Science.gov (United States)

    Cienciala, P.; Hassan, M. A.

    2015-12-01

    In this research we linked spatial variability of invertebrate drift characteristics (e.g. flux, concentration, mean body size) in a mountain stream to channel morphology and hydraulic properties such as at-a-point and depth-averaged velocity and shear velocity. The study was conducted in East Creek, a small stream in British Columbia in which reach-scale morphology transitions from cobble-dominated plane-bed to gravel-bed pool-riffle. To achieve our goal, we collected vertical profiles of invertebrate drift and time-averaged velocity in various morphological units within the study reaches. The data were analyzed using linear mixed model. Our reach-scale results suggested that, generally, the study reaches had statistically similar drift characteristics despite their contrasting morphologies. At the within-reach scale, different drift characteristics displayed different trends in relation to morphological and hydraulic properties of the channel. Longitudinally, highest drift flux occurred in riffle-pool transitions. We attributed this finding primarily to higher flow velocity because there were no statistically significant differences in drift concentration between morphological units. In the vertical dimension, highest drift flux occurred near the surface owing to a combination of higher drift concentration and higher flow velocity. A different pattern was observed for mean body size of drifting invertebrates. On average, body size was smallest in riffle-pool transitions and largest near the bed. The combination of velocity, drift concentration, and drift body size structure resulted in similar biomass flux estimates in all morphological units. In the vertical dimension, biomass flux appeared to be highest near the water surface. Generally, hydraulic variables seemed to be relatively poor predictors of drift concentration and mean body size of drifting invertebrates. Our findings reveal a complex relationship between channel morphology and hydraulics and various

  7. Roles of epiphytes associated with macroalgae in benthic food web of a eutrophic coastal lagoon

    Science.gov (United States)

    Zheng, Xinqing; Huang, Lingfeng; Lin, Rongcheng; Du, Jianguo

    2015-11-01

    Macroalgae perform a significant function in the trophic dynamics in many coastal lagoons, and conventionally, they are the key trophic base that fuels the overall aquatic food web. However, few studies have considered the trophic contribution of epiphytes that attach to macroalgae in the diet of benthic primary consumers or their contribution to the trophic base of the aquatic food web. In this study, macrobenthic invertebrate biomass was combined with multiple-isotope-mixing models to distinguish the trophic importance of macroalgae and their associated epiphytic assemblages in the benthic food web during Ulva lactuca bloom in the Yundang Lagoon, a eutrophic coastal lagoon in Xiamen, China. Amphipods primarily dominated the zoobenthos, with the biomass varied from 40.9 g/m2 in January to 283.9 g/m2 in March. They mainly fed on U. lactuca and its associated epiphytes, which jointly contributed more than 60% to amphipod diets, but species-specific feeding habits were exhibited among amphipods. Using the zoobenthos biomass as a weighting factor, the contribution of U. lactuca and its epiphytes to total benthic communities during U. lactuca bloom exceeded 65%.The epiphytes were clearly utilized more than U. lactuca, with a median contribution ranging from 48.5% in January to 66.6% in March. Our findings demonstrate the trophic importance of the epiphytes in macroalgae-based coastal habitats, as found in many seagrass beds. Therefore, we propose that further food web studies of macroalgae-based ecosystems should pay greater attention to the role of epiphytes.

  8. Organic compounds temporal trends at some invertebrate species from the Balearics, Western Mediterranean.

    Science.gov (United States)

    Deudero, S; Box, A; March, D; Valencia, J M; Grau, A M; Tintore, J; Calvo, M; Caixach, J

    2007-08-01

    Concentrations of persistent organic pollutants (POPs) such as hexachlorobenzene (HCB), dichlore diphenyl trichloretane (DDT), polychlorinated biphenyls (PCBs), and gamma-hexachlorocyclohexane (gamma-HCH or lindane) were determined in tissue of marine benthic invertebrates such as Mytilus galloprovincialis, Chamelea gallina, Venus verrucosa, Lithophaga lithophaga and Paracentrotus lividus. Species were selected due to their habitat, trophic level, feeding behaviour and their consumption. Invertebrate species were systematically sampled from December 1996 to December 2005 from several sites along the Balearic Islands. The highest concentrations of PCBs (785ng/g lipid) were found in M. galloprovincialis while the lowest concentrations were found in the sea-urchin P. lividus (193ng/g lipid). Among the 7 PCB quantified congeners the higher values are mainly obtained for CB138 and CB153. All bivalves presented higher PCBs contents than the sea-urchin P. lividus are possibly linked with the bioaccumulation process of POPs throughout the food web and to differential detoxifying mechanisms. The concentration of SigmaDDT exceeds that of HCB and gamma-HCH at all species and sampling stations. DDT concentrations ranged from 0.4ng/g ww at the bivalve C. gallina in 2002, to values of 15.8ng/g ww at the bivalve L. lithophaga in 1998. The values obtained for the organic compounds (HCH, HCB, PCBs, DDT) depend upon the place and year of sampling and are compared to values found by other authors for the mussel M. galloprovincialis in other Mediterranean areas. gamma-HCH and HCB were found in lower concentrations than the other POPs. PMID:17524450

  9. Influence of Water Quality on the Diversity and Distribution of Macro-Invertebrates in Hiwane Second Order Stream, Northern Ethiopia

    Directory of Open Access Journals (Sweden)

    Tsegazeabe H. Haileselasie

    2012-04-01

    Full Text Available Understanding the pattern and process related to biodiversity is a greatest challenge to the science of biological conservation. Furthermore, diversity of tropical aquatic ecosystems is severely threatened by anthropogenic activities. What is more, the continuum of most of the tropical river is interrupted by several man-made activities contributing to adverse effects which hamper provision of good quality of water. Traditionally the quality of water is assessed by physico-chemical means but recent studies have focused on the use of organisms (biota in water quality assessment for streams and lakes. Here we assessed the influence of water quality on the diversity and distribution of macroinvertebrates in Hiwane second order stream with primary objective to determine the ecological water quality status of Hiwane stream at different sampling sites using rapid field assessment screening methodology. A total of 5 sites (stream sections were selected and 4 of the sampling sites were within the city Hiwane. However, a reference site outside of the city of Hiwane was included. There were 29 taxa of benthic invertebrates belonging to ephemeroptera, odonata, plecoptera, coleoptera, trichoptera, diptera and hirudenia, among others, recorded from the river. Among these, members of Trichoptera and Ephemeroptera were predominant in density. Furthermore, species diversity is positively correlated with water quality. Since, man-made activities has lead to depletion of biota, any human activity in the drainage area which may cause changes among physico-chemical parameter could lead to a severe impact on the benthic invertebrates of Hiwane stream river. Thus, we recommend that effluent from the town should be carefully managed.

  10. JAKs and STATs in invertebrate model organisms.

    Science.gov (United States)

    Dearolf, C R

    1999-09-01

    Invertebrate organisms provide systems to elucidate the developmental roles of Janus kinase (JAK)/signal transducers and activators of transcription (STAT) signaling pathways, thereby complementing research conducted with mammalian cells and animals. Components of the JAK/STAT protein pathway have been identified and characterized in the fruit fly Drosophila melanogaster and the cellular slime mold Dictyostelium discoideum. This review summarizes the molecular and genetic data obtained from these model organisms. In particular, a Drosophila JAK/STAT pathway regulates normal segmentation, cell proliferation, and differentiation, and hyperactivation of the pathway leads to tumor formation and leukemia-like defects. A Dictyostelium STAT regulates the development of stalk cells during the multicellular part of the life cycle. Future research utilizing these organisms should continue to provide insights into the roles and regulation of these proteins and their signaling pathways. PMID:10526575

  11. Sensitivity of Coastal Environments and Wildlife to Spilled Oil: South Florida: BENTHIC (Benthic Polygons)

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — This data set contains benthic habitats, including coral reef and hardbottom, seagrass, algae, and others in [for] South Florida. Vector polygons in the data set...

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

    International Nuclear Information System (INIS)

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

  13. Study on Community Structure of Macro-invertebrates in Tributaries of Three Gorges Reservoir%三峡库区支流底栖动物群落结构研究

    Institute of Scientific and Technical Information of China (English)

    池仕运; 胡菊香; 陈胜; 张原圆

    2011-01-01

    Macro-invertebrates samples were collected in 26 major tributaries of the Three Gorges Reservoir region in April,2010.A total of 97 species were recorded,including 78 species of aquatic insects,10 species of mollusks,and 6 species of Oligochaeta.Common species occurred in 26 tributaries mainly included Ephemeridae sp.,Ephemerellidae sp.,Baetis sp.,Caenis sp.,Choroterpes sp.,Ecdyonurus sp.,Othacladius sp.and Thieneminimyia sp..The average density was 673.22 ind./m2,while the average biomass was 9.9398 g/m2.The result of MDS analysis showed that the locations of Yulinhe River,Longxihe River,Changtanxi River and Jialingjiang River were far away from the other 22 rivers.Clustering analysis result showed that there was high species similarity between Baolonghe River and Tongxihe River,as well as Tongzhuanghe River and Dalinghe River,Zhaxihe River and Huangjinhe River,Modaoxi River and Xiaojiang River,Daxihe River and Guanduhe River,Longhe River and Lixiangxi River,Yulinghe River and Qijiang River,Longxihe River and Changtanxi River.Biodiversity analysis results showed that Shannon-Wiener indexes ranged from 0.6365 to 2.9329,averating at 1.6120,while Margalef indexes ranged from 0.6266 to 5.3074,averaging at 2.2976.%2010年4月对三峡库区26条主要支流的底栖动物进行了采集,经鉴定共检出97种;其中,水生昆虫78种,软体动物10种,寡毛纲6种。常见种为蜉蝣科(Ephemeridae)、小蜉科(Ephemerellidae)、四节蜉属(Baetis)、细蜉属(Caenis)、宽基蜉属(Choroterpes)、扁蚴蜉属(Ecdyonurus)稚虫及直突摇蚊属(Orthocladius)、斑特突摇蚊属(Thienemanimyia)幼虫,平均密度673.22个/m2,平均生物量9.9398g/m2。MDS分析表明,御临河、龙溪河、长滩溪和嘉陵江站点明显偏离其他22条河流;种类组成聚类分析表明,抱龙河和汤溪河、童庄河和大宁河、咤溪河和黄金河、磨刀溪和小江、大溪河和官渡河、龙河与梨香溪、御临河与綦江

  14. Invertebrate diversity classification using self-organizing map neural network: with some special topological functions

    OpenAIRE

    WenJun Zhang; QuHuan Li

    2014-01-01

    In present study we used self-organizing map (SOM) neural network to conduct the non-supervisory clustering of invertebrate orders in rice field. Four topological functions, i.e., cossintopf, sincostopf, acossintopf, and expsintopf, established on the template in toolbox of Matlab, were used in SOM neural network learning. Results showed that clusters were different when using different topological functions because different topological functions will generate different spatial structure of ...

  15. Diversity and distribution of diapausing aquatic invertebrates in inland wetlands: An ecosystem conservation viewpoint

    DEFF Research Database (Denmark)

    Muñoz, Joaquin

    2010-01-01

    exotic species. Recent large-scale ecological and genetic studies across several countries and continents indicate that population structure, regional endemism, and geographic speciation patterns are common in passively dispersed aquatic invertebrates contradicting previous predictions of homogeneous...... processes determining the biogeography of cosmopolitan species are needed. Further knowledge of these issues should provide invaluable information allowing development of appropriate conservation management policies for inland waters across entire ecosystems, landscapes, and geographic regions....

  16. The ecology of chalk-stream invertebrates studied in a recirculating stream

    OpenAIRE

    LADLE M.; Welton, J. S.

    1984-01-01

    To study and qualify the factors influencing interactions between various trophic levels in natural hard-water streams, a recirculating artificial stream channel was constructed. This structure has enabled patterns of population change of stream fauna to be observed under partially controlled physical and chemical conditions. Initial colonization of the substratum by invertebrates and subsequent succession was studied along with depth distribution and growth and production studies of inverteb...

  17. Botanical Repellents and Pesticides Traditionally Used Against Haematophagous Invertebrates in Lao PDR

    OpenAIRE

    Vongsombath, Chanda

    2011-01-01

    Haematophagous parasites and disease vectors such as leeches, ticks, mites, lice, bed bugs, mosquitoes, and myiasis-causing fly larvae are common health problems in Lao Peoples Democratic Republic (Lao PDR). A main aim of my field work in Lao PDR in 2006-2010 was to document traditional knowledge among different ethnic groups about plants that people use to repel or to kill blood-feeding invertebrates. We carried out structured interviews in 66 villages comprising 17 ethnic groups, covering a...

  18. The role of metacommunity processes in shaping invertebrate rock pool communities along a dispersal gradient

    OpenAIRE

    Vanschoenwinkel, Bram; De Vries, Chris; Seaman, Maitland; Brendonck, Luc

    2007-01-01

    Explaining the variance of local communities in a spatial-environmental matrix is one of the core interests of ecology today. Recent progress in metacommunity theory has made a substantial contribution to this field, however good empirical data in support of available theories are still relatively scarce. In this study we sampled a cluster of 36 temporary rock pools four times during one season to assess invertebrate metacommunity structure and dynamics and to search for steering processes an...

  19. Characterization of an individual neural crest-like cell lineage in the invertebrate chordate Ciona intestinalis

    OpenAIRE

    Cone, Angela C.

    2008-01-01

    During embryogenesis, all chordate embryos undergo neurulation to form a dorsal, hollow nerve cord. Neural crest cells (NCC), considered a vertebrate innovation, arise during neurulation and later differentiate into a multitude of tissues that account for much of the structural complexity that distinguishes craniates from invertebrate chordates [1, 2]. NCCs are induced and specified at the border of the neural and non-neural ectoderm by a complex network of inductive signals and transcription...

  20. The importance of litter for interactions between terrestrial plants and invertebrates

    OpenAIRE

    Gelfgren, Maria

    2010-01-01

    According to the exploitation ecosystem hypothesis (EEH), terrestrial ecosystems are characterized by well defined trophic levels and strong trophic interactions with community level tropic cascades. In unproductive terrestrial habitats as tundra heaths, the energy shunt from litter and apparent competition between herbivores and detritivores are expected to be important for the structure and dynamics of the invertebrate community. The aim of this study was to test this hypothesis by investig...

  1. Effects of Elevated CO2 on Litter Chemistry and Subsequent Invertebrate Detritivore Feeding Responses

    OpenAIRE

    Dray, Matthew W.; Crowther, Thomas W.; Thomas, Stephen M; A’Bear, A. Donald; Godbold, Douglas L.; Ormerod, Steve J.; Hartley, Susan E.; Jones, T. Hefin

    2014-01-01

    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 glutinos...

  2. Antarctic Porifera database from the Spanish benthic expeditions

    Directory of Open Access Journals (Sweden)

    Pilar Rios

    2014-04-01

    Full Text Available The information about the sponges in this dataset is derived from the samples collected during five Spanish Antarctic expeditions: Bentart 94, Bentart 95, Gebrap 96, Ciemar 99/00 and Bentart 2003. Samples were collected in the Antarctic Peninsula and Bellingshausen Sea at depths ranging from 4 to 2044 m using va­rious sampling gears.The Antarctic Porifera database from the Spanish benthic expeditions is unique as it provides in­formation for an under-explored region of the Southern Ocean (Bellingshausen Sea. It fills an information gap on Antarctic deep-sea sponges, for which there were previously very few data.This phylum is an important part of the Antarctic biota and plays a key role in the structure of the Antarctic marine benthic community due to its considerable diversity and predominance in different areas. It is often a dominant component of Southern Ocean benthic communities.The quality of the data was controlled very thoroughly with GPS systems onboard the R/V Hesperides and by checking the data against the World Porifera Database (which is part of the World Register of Marine Species, WoRMS. The data are therefore fit for completing checklists, inclusion in biodivers­ity pattern analysis and niche modelling. The authors can be contacted if any additional information is needed before carrying out detailed biodiversity or biogeographic studies.The dataset currently contains 767 occurrence data items that have been checked for systematic reliability. This database is not yet complete and the collection is growing. Specimens are stored in the author’s collection at the Spanish Institute of Oceanography (IEO in the city of Gijón (Spain. The data are available in GBIF.

  3. Antarctic Porifera database from the Spanish benthic expeditions.

    Science.gov (United States)

    Rios, Pilar; Cristobo, Javier

    2014-01-01

    THE INFORMATION ABOUT THE SPONGES IN THIS DATASET IS DERIVED FROM THE SAMPLES COLLECTED DURING FIVE SPANISH ANTARCTIC EXPEDITIONS: Bentart 94, Bentart 95, Gebrap 96, Ciemar 99/00 and Bentart 2003. Samples were collected in the Antarctic Peninsula and Bellingshausen Sea at depths ranging from 4 to 2044 m using various sampling gears. The Antarctic Porifera database from the Spanish benthic expeditions is unique as it provides information for an under-explored region of the Southern Ocean (Bellingshausen Sea). It fills an information gap on Antarctic deep-sea sponges, for which there were previously very few data. This phylum is an important part of the Antarctic biota and plays a key role in the structure of the Antarctic marine benthic community due to its considerable diversity and predominance in different areas. It is often a dominant component of Southern Ocean benthic communities. The quality of the data was controlled very thoroughly with GPS systems onboard the R/V Hesperides and by checking the data against the World Porifera Database (which is part of the World Register of Marine Species, WoRMS). The data are therefore fit for completing checklists, inclusion in biodiversity pattern analysis and niche modelling. The authors can be contacted if any additional information is needed before carrying out detailed biodiversity or biogeographic studies. The dataset currently contains 767 occurrence data items that have been checked for systematic reliability. This database is not yet complete and the collection is growing. Specimens are stored in the author's collection at the Spanish Institute of Oceanography (IEO) in the city of Gijón (Spain). The data are available in GBIF. PMID:24843257

  4. Allelopathy in benthic and littoral areas : case studies on allelochemicals from benthic cyanobacteria and submersed macrophytes

    OpenAIRE

    Gross, Elisabeth

    1999-01-01

    Photosynthetic organisms in littoral and benthic habitats are in general situated in close proximity to their competitors. Benthic algae and cyanobacteria compete for space and grow adjacent to each other. Submersed macrophytes can be overgrown by epiphytic algae and are surrounded by other macrophytes and phytoplankton. The particular spatial setup in these habitats makes allelopathy a powerful strategy. Released compounds can more or less directly reach and act on target organisms. Allelopa...

  5. Quo vadis NW Black Sea benthic ecosystems?

    Science.gov (United States)

    Traian Gomoiu, Marian

    2016-04-01

    / thalasoterapy. Black Sea ecosystem restoration - Certainties and Uncertainties: Pressure on the Danube and other rivers has decreased, chemical discharges have decreased obviously, and yet there appear phenomena of water flowering - "red waters", hypoxia is still present at times and there is mass mortality of fish and other benthic organisms. Why? Signs of recovery should be considered cautiously and uncertainties may be resolved only in a longer time by increasing our scientific efforts. The results of the EU FP7 Project PERSEUS led to the identification of three important issues that should be resolved in order to achieve good environmental status: • Applying an adaptive management to increase the resilience of the ecosystems and to diminish the vulnerability of biodiversity; • Necessity of participative approach by stakeholders; • Identifying and obtaining adequate financial support for new R-D-I projects. Who are the actors in addressing and implementing the actions? • Academic educational and research institutions for adequate working condition; • More specialists trained for taxonomic groups; • Reasonable diversity of coordinating specialists, capable team leaders / satisfactory work packages; • Attracting NGO members towards nature conservation issues; • Resonable stakeholders committed to environmental issues. Studying the results of researches carried out by GeoEcoMar on the Romanian Black Sea coast in recent years, the author concluded that the major problems hampering progress towards a good ecosystem in NW Bent Black Sea are: • lack of diversity in the fields of research, both in theoretical and applied realms; • structural and functional consequences of ecological pressures and the disordered state of the ecosystems in the periods of paroxysmal eutrophication / pollution at the end of the 20th Century; • scarcity of data and knowledge on the Social-Economic System; • high costs of the new marine technology used directly in the sea and

  6. Soil invertebrates as bioindicators of urban soil quality

    International Nuclear Information System (INIS)

    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.

  7. Benthic trophic network in the Bay of Banyuls-sur-Mer (northwest Mediterranean, France): An assessment based on stable carbon and nitrogen isotopes analysis

    Science.gov (United States)

    Carlier, Antoine; Riera, Pascal; Amouroux, Jean-Michel; Bodiou, Jean-Yves; Grémare, Antoine

    2007-03-01

    The benthic trophic network in the Bay of Banyuls-sur-Mer was studied through the carbon and nitrogen isotopic characterization of a large set of soft-bottom macrobenthic invertebrates, fishes and potential food sources. Continental inputs as well as seagrass meadows did not contribute significantly to this benthic trophic network as indicated by: (1) the difference between their δ 13C signatures (respectively -28.4‰ and -9.5‰) and those of sampled animals (between -21.0‰ and -14.6‰); and (2) their low inputs to the bay. Benthic primary consumers fed mostly on surface sediment organic matter (SSOM), which tightly interacts with suspended particulate organic matter (SPOM) and sedimenting organic matter (STOM) due to sediment resuspension. Our results also suggest the occurrence of a transfer between marine SPOM and some invertebrates (e.g. Veretillum cynomorium) and fishes (e.g. Boops boops and Spicara melanurus) through zooplankton. Moreover, the different types of primary consumers (i.e., suspension-feeders, interface-feeders, surface deposit-feeders and subsurface deposit-feeders) preferentially used distinct fractions of the heterogeneous SPOM-STOM-SSOM pool. These differences were mostly related with feeding depth and resulted in distinct isotopic signatures. Differences in the stable isotopic ratios of suspension and interface-feeders could also partly reflect the use of microphytobenthos by the later. Assuming a 15N-enrichment factor of 3.4‰ between the lower and upper ranges of two successive trophic levels, we estimated that the benthic food web of the Bay of Banyuls-sur-Mer was composed of 4 trophic levels. The comparison with our δ 13C values suggests that the whole trophic food chain is affected by continental inputs at the immediate vicinity of the Rhône River mouth even though these effects are maximal for deposit-feeding and carnivorous polychaetes.

  8. Molar tooth carbonates and benthic methane fluxes in Proterozoic oceans

    Science.gov (United States)

    Shen, Bing; Dong, Lin; Xiao, Shuhai; Lang, Xianguo; Huang, Kangjun; Peng, Yongbo; Zhou, Chuanming; Ke, Shan; Liu, Pengju

    2016-01-01

    Molar tooth structures are ptygmatically folded and microspar-filled structures common in early- and mid-Proterozoic (~2,500-750 million years ago, Ma) subtidal successions, but extremely rare in rocks dimethyl sulphide and methanethiol) in euxinic or H2S-rich seawaters that were widespread in Proterozoic continental margins. In this convergence zone, methyl sulphides served as a non-competitive substrate supporting methane generation and methanethiol inhibited anaerobic oxidation of methane, resulting in the buildup of CH4, formation of degassing cracks in sediments and an increase in the benthic methane flux from sediments. Precipitation of crack-filling microspar was driven by methanogenesis-related alkalinity accumulation. Deep ocean ventilation and oxygenation around 750 Ma brought molar tooth structures to an end.

  9. Effects of a chelating resin on metal bioavailability and toxicity to estuarine invertebrates: Divergent results of field and laboratory tests

    Energy Technology Data Exchange (ETDEWEB)

    Wilkie, Emma M., E-mail: ewilkie@bio.mq.edu.a [Department of Environmental Sciences, University of Technology Sydney, Broadway, NSW 2007 (Australia); Ecotoxicology and Environmental Contaminants Section, Department of Environment and Climate Change, Lidcombe, NSW 1825 (Australia); Roach, Anthony C. [Ecotoxicology and Environmental Contaminants Section, Department of Environment and Climate Change, Lidcombe, NSW 1825 (Australia); Micevska, Tina [Centre for Environmental Contaminants Research, CSIRO Land and Water, Menai, NSW 2234 (Australia); Kelaher, Brendan P.; Bishop, Melanie J. [Department of Environmental Sciences, University of Technology Sydney, Broadway, NSW 2007 (Australia)

    2010-05-15

    Benthic invertebrates can uptake metals through diffusion of free ion solutes, or ingestion of sediment-bound forms. This study investigated the efficacy of the metal chelating resin SIR 300{sup TM} in adsorbing porewater metals and isolating pathways of metal exposure. A field experiment (Botany Bay, Sydney, Australia) and a laboratory toxicity test each manipulated the availability of porewater metals within contaminated and uncontaminated sediments. It was predicted that within contaminated sediments, the resin would adsorb porewater metals and reduce toxicity to invertebrates, but in uncontaminated sediments, the resin would not significantly affect these variables. Whereas in the laboratory, the resin produced the predicted results, in the field the resin increased porewater metal concentrations of contaminated sediments for at least 34 days and decreased abundances of four macroinvertebrate groups, and richness in all sediments. These contrasting findings highlight the limits of extrapolating the results of laboratory experiments to the field environment. - Laboratory experiments do not predict the effects on porewater metals or macroinvertebrates of adding a chelating resin to metal-contaminated field sediments.

  10. Effects of a chelating resin on metal bioavailability and toxicity to estuarine invertebrates: Divergent results of field and laboratory tests

    International Nuclear Information System (INIS)

    Benthic invertebrates can uptake metals through diffusion of free ion solutes, or ingestion of sediment-bound forms. This study investigated the efficacy of the metal chelating resin SIR 300TM in adsorbing porewater metals and isolating pathways of metal exposure. A field experiment (Botany Bay, Sydney, Australia) and a laboratory toxicity test each manipulated the availability of porewater metals within contaminated and uncontaminated sediments. It was predicted that within contaminated sediments, the resin would adsorb porewater metals and reduce toxicity to invertebrates, but in uncontaminated sediments, the resin would not significantly affect these variables. Whereas in the laboratory, the resin produced the predicted results, in the field the resin increased porewater metal concentrations of contaminated sediments for at least 34 days and decreased abundances of four macroinvertebrate groups, and richness in all sediments. These contrasting findings highlight the limits of extrapolating the results of laboratory experiments to the field environment. - Laboratory experiments do not predict the effects on porewater metals or macroinvertebrates of adding a chelating resin to metal-contaminated field sediments.

  11. An unusually large phytoplankton spring bloom drives rapid changes in benthic diversity and ecosystem function

    Science.gov (United States)

    Zhang, Qingtian; Warwick, Richard M.; McNeill, Caroline L.; Widdicombe, Claire E.; Sheehan, Aaron; Widdicombe, Stephen

    2015-09-01

    In 2012, the Western English Channel experienced an unusually large and long-lived phytoplankton spring bloom. When compared with data from the past 20 years, average phytoplankton biomass at Station L4 (part of the Western Channel Observatory) was approximately 3× greater and lasted 50% longer than any previous year. Regular (mostly weekly) box core samples were collected from this site before, during and after the bloom to determine its impact on macrofaunal abundance, diversity, biomass, community structure and function. The spring bloom of 2012 was shown to support a large and rapid response in the majority of benthic taxa and functional groups. However, key differences in the precise nature of this response, as well as in its timing, was observed between different macrofauna feeding groups. Deposit feeders responded almost instantly at the start of the bloom, primarily thorough an increase in abundance. Suspension feeders and opportunistic/predatory/carnivorous taxa responded slightly more slowly and primarily with an increase in biomass. At the end of the bloom a rapid decline in macrobenthic abundance, diversity and biomass closely followed the decline in phytoplankton biomass. With suspension feeders showing evidence of this decline a few weeks before deposit feeders, it was concluded that this collapse in benthic communities was driven primarily by food availability and competition. However, it is possible that environmental hypoxia and the presence of toxic benthic cyanobacteria could also have contributed to this decline. This study shows evidence for strong benthic-pelagic coupling at L4; a shallow (50 m), coastal, fine-sand habitat. It also demonstrates that in such habitats, it is not just planktonic organisms that demonstrate clear community phenology. Different functional groups within the benthic assemblage will respond to the spring bloom in specific manner, with implications for key ecosystem functions and processes, such as secondary production

  12. ACTH in invertebrates: a molecule for all seasons

    Directory of Open Access Journals (Sweden)

    D Malagoli

    2016-02-01

    Full Text Available In vertebrate and invertebrate models, adrenocorticotropic hormone (ACTH belongs to the melanocortin group of related peptides, which share a common precursor, pro-opiomelanocortin (POMC. Functional experiments indicate that in invertebrates, ACTH plays a major role in several biological functions. ACTH, whose effects have been conserved during evolution more than its amino acidic sequence, is, directly or indirectly, able to contrast agents that perturb a body’s homeostasis. Here we review evidence highlighting the involvement of ACTH and ACTH-like molecules in the response of invertebrate models versus immune, environmental and parasitic challenges.

  13. Do Changes in Current Flow as a Result of Arrays of Tidal Turbines Have an Effect on Benthic Communities?

    Science.gov (United States)

    Kregting, Louise; Elsaesser, Bjoern; Kennedy, Robert; Smyth, David; O'Carroll, Jack; Savidge, Graham

    2016-01-01

    Arrays of tidal energy converters have the potential to provide clean renewable energy for future generations. Benthic communities may, however, be affected by changes in current speeds resulting from arrays of tidal converters located in areas characterised by strong currents. Current speed, together with bottom type and depth, strongly influence benthic community distributions; however the interaction of these factors in controlling benthic dynamics in high energy environments is poorly understood. The Strangford Lough Narrows, the location of SeaGen, the world's first single full-scale, grid-compliant tidal energy extractor, is characterised by spatially heterogenous high current flows. A hydrodynamic model was used to select a range of benthic community study sites that had median flow velocities between 1.5-2.4 m/s in a depth range of 25-30 m. 25 sites were sampled for macrobenthic community structure using drop down video survey to test the sensitivity of the distribution of benthic communities to changes in the flow field. A diverse range of species were recorded which were consistent with those for high current flow environments and corresponding to very tide-swept faunal communities in the EUNIS classification. However, over the velocity range investigated, no changes in benthic communities were observed. This suggested that the high physical disturbance associated with the high current flows in the Strangford Narrows reflected the opportunistic nature of the benthic species present with individuals being continuously and randomly affected by turbulent forces and physical damage. It is concluded that during operation, the removal of energy by marine tidal energy arrays in the far-field is unlikely to have a significant effect on benthic communities in high flow environments. The results are of major significance to developers and regulators in the tidal energy industry when considering the environmental impacts for site licences. PMID:27560657

  14. NOAA Point Shapefile- Benthic Habitat Classifications from Phantom S2 ROV Underwater Video, US Virgin Islands, Project NF-05-05, 2005, UTM 20N WGS84

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — This dataset contains a point shapefile with benthic habitat classifications of vertical relief, geomorphological structure, substrate, and biological cover for...

  15. NOAA Point Shapefile- Benthic Habitat Classifications from Phantom S2 ROV Underwater Video, US Virgin Islands, Project NF-06-03, 2006, UTM 20N WGS84

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — This dataset contains a point shapefile with benthic habitat classifications of vertical relief, geomorphological structure, substrate, and biological cover for...

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

    Directory of Open Access Journals (Sweden)

    N. Glock

    2012-12-01

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

  17. Comparing nearshore benthic and pelagic prey as mercury sources to lake fish: the importance of prey quality and mercury content.

    Science.gov (United States)

    Karimi, Roxanne; Chen, Celia Y; Folt, Carol L

    2016-09-15

    Mercury (Hg) bioaccumulation in fish poses well-known health risks to wildlife and humans through fish consumption. Yet fish Hg concentrations are highly variable, and key factors driving this variability remain unclear. One little studied source of variation is the influence of habitat-specific feeding on Hg accumulation in lake fish. However, this is likely important because most lake fish feed in multiple habitats during their lives, and the Hg and caloric content of prey from different habitats can differ. This study used a three-pronged approach to investigate the extent to which habitat-specific prey determine differences in Hg bioaccumulation in fish. This study first compared Hg concentrations in common nearshore benthic invertebrates and pelagic zooplankton across five lakes and over the summer season in one lake, and found that pelagic zooplankton generally had higher Hg concentrations than most benthic taxa across lakes, and over a season in one lake. Second, using a bioenergetics model, the effects of prey caloric content from habitat-specific diets on fish growth and Hg accumulation were calculated. This model predicted that the consumption of benthic prey results in lower fish Hg concentrations due to higher prey caloric content and growth dilution (high weight gain relative to Hg from food), in addition to lower prey Hg levels. Third, using data from the literature, links between fish Hg content and the degree of benthivory, were examined, and showed that benthivory was associated with reduced Hg concentrations in lake fish. Taken together, these findings support the hypothesis that higher Hg content and lower caloric content make pelagic zooplankton prey greater sources of Hg for fish than nearshore benthic prey in lakes. Hence, habitat-specific foraging is likely to be a strong driver of variation in Hg levels within and between fish species. PMID:27173839

  18. History of benthic research in the English Channel: From general patterns of communities to habitat mosaic description

    Science.gov (United States)

    Dauvin, Jean-Claude

    2015-06-01

    Benthic studies in the English Channel (EC), a shallow megatidal and epicontinental sea, began in the 1960s and 1970s with the work of teams led by Norman Holme (UK) and Louis Cabioch (F). During this period, benthic sampling was mainly qualitative, i.e. using a device such as the 'Rallier du Baty' dredge in the case of the French team and a modified anchor dredge in the case of the British team. Studies were focused on acquiring knowledge of the main distributions of benthic communities and species. Surveys on the scale of the whole EC led to the recognition of general features and two main patterns were identified: 1) the role of hydrodynamics on the spatial distribution of sediment, benthic species and communities; 2) the presence of a west-east climatic gradient of faunal impoverishment. Benthic studies in the 1980s-1990s were focused on the beginning of the implementation of long-term survey at a limited number of sites to identify seasonal and multi-annual changes. In the first decade of the 2000s, the implementation of the European Water Framework Directive and the Marine Strategy Framework Directive to define the Ecological Quality Status of marine environments increased the need to acquire better information of the structure and functioning of benthic communities, since benthic species and habitats were recognised as good indicators of human pressure on marine ecosystems. Faced with the increase of human maritime activities, the appearance of invasive species and the need to preserve sensitive marine habitats, benthic studies have been focused on developing a 'toolkit' to help in the decision-making and planning for both sound governance and sustainable management of marine resources and human activities in the English Channel. Multidisciplinary approaches were used to differentiate habitats in a more precise detail. Both indirect (side-scan sonar, ROV) and direct (grab sampling with benthos identification and grain-size analyses) approaches were used and

  19. High-resolution computed tomography reconstructions of invertebrate burrow systems.

    Science.gov (United States)

    Hale, Rachel; Boardman, Richard; Mavrogordato, Mark N; Sinclair, Ian; Tolhurst, Trevor J; Solan, Martin

    2015-01-01

    The architecture of biogenic structures can be highly influential in determining species contributions to major soil and sediment processes, but detailed 3-D characterisations are rare and descriptors of form and complexity are lacking. Here we provide replicate high-resolution micro-focus computed tomography (μ-CT) data for the complete burrow systems of three co-occurring, but functionally contrasting, sediment-dwelling inter-tidal invertebrates assembled alone, and in combination, in representative model aquaria. These data (≤ 2,000 raw image slices aquarium(-1), isotropic voxel resolution, 81 μm) provide reference models that can be used for the development of novel structural analysis routines that will be of value within the fields of ecology, pedology, geomorphology, palaeobiology, ichnology and mechanical engineering. We also envisage opportunity for those investigating transport networks, vascular systems, plant rooting systems, neuron connectivity patterns, or those developing image analysis or statistics related to pattern or shape recognition. The dataset will allow investigators to develop or test novel methodology and ideas without the need to generate a complete three-dimensional computation of exemplar architecture. PMID:26396743

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

    Science.gov (United States)

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

    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 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 sensitive to glacier retreat; and (ii) conservation efforts/resources to be better directed in alpine aquatic systems. PMID:24650750

  1. Assessing and monitoring cryptic reef diversity of colonizing marine invertebrates across the U.S.-affiliated islands and atolls in the Pacific since 2008 using the Autonomous Reef Monitoring Structure (ARMS) method

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — To support a long-term program for sustainable management and conservation of coral reef ecosystems, from 2008, Autonomous Reef Monitoring Structures (ARMS) have...

  2. Fish-derived nutrient hotspots shape coral reef benthic communities.

    Science.gov (United States)

    Shantz, Andrew A; Ladd, Mark C; Schrack, Elizabeth; Burkepile, Deron E

    2015-12-01

    Animal-derived nutrients play an important role in structuring nutrient regimes within and between ecosystems. When animals undergo repetitive, aggregating behavior through time, they can create nutrient hotspots where rates of biogeochemical activity are higher than those found in the surrounding environment. In turn, these hotspots can influence ecosystem processes and community structure. We examined the potential for reef fishes from the family Haemulidae (grunts) to create nutrient hotspots and the potential impact of these hotspots on reef communities. To do so, we tracked the schooling locations of diurnally migrating grunts, which shelter at reef sites during the day but forage off reef each night, and measured the impact of these fish schools on benthic communities. We found that grunt schools showed a high degree of site fidelity, repeatedly returning to the same coral heads. These aggregations created nutrient hotspots around coral heads where nitrogen and phosphorus delivery was roughly 10 and 7 times the respective rates of delivery to structurally similar sites that lacked schools of these fishes. In turn, grazing rates of herbivorous fishes at grunt-derived hotspots were approximately 3 times those of sites where grunts were rare. These differences in nutrient delivery and grazing led to distinct benthic communities with higher cover of crustose coralline algae and less total algal abundance at grunt aggregation sites. Importantly, coral growth was roughly 1.5 times greater at grunt hotspots, likely due to the important nutrient subsidy. Our results suggest that schooling reef fish and their nutrient subsidies play an important role in mediating community structure on coral reefs and that overfishing may have important negative consequences on ecosystem functions. As such, management strategies must consider mesopredatory fishes in addition to current protection often offered to herbivores and top-tier predators. Furthermore, our results suggest that

  3. Effect of hypoxia and anoxia on invertebrate behaviour: ecological perspectives from species to community level

    Science.gov (United States)

    Riedel, B.; Pados, T.; Pretterebner, K.; Schiemer, L.; Steckbauer, A.; Haselmair, A.; Zuschin, M.; Stachowitsch, M.

    2014-03-01

    Coastal hypoxia and anoxia have become a global key stressor to marine ecosystems, with almost 500 dead zones recorded worldwide. By triggering cascading effects from the individual organism to the community- and ecosystem level, oxygen depletions threaten marine biodiversity and can alter ecosystem structure and function. By integrating both physiological function and ecological processes, animal behaviour is ideal for assessing the stress state of benthic macrofauna to low dissolved oxygen. The initial response of organisms can serve as an early warning signal, while the successive behavioural reactions of key species indicate hypoxia levels and help assess community degradation. Here we document the behavioural responses of a representative spectrum of benthic macrofauna in the natural setting in the Northern Adriatic Sea (Mediterranean). We experimentally induced small-scale anoxia with a benthic chamber in 24 m depth to overcome the difficulties in predicting the onset of hypoxia, which often hinders full documentation in the field. The behavioural reactions were documented with a time-lapse camera. Oxygen depletion elicited significant and repeatable changes in general (visibility, locomotion, body movement and posture, location) and species-specific reactions in virtually all organisms (302 individuals from 32 species and 2 species groups). Most atypical (stress) behaviours were associated with specific oxygen thresholds: arm-tipping in the ophiuroid Ophiothrix quinquemaculata, for example, with the onset of mild hypoxia (structure and ecosystem functioning. This integrated approach can transport complex ecological processes to the public and decision-makers and help define specific monitoring, assessment and conservation plans.

  4. Final Critical Habitat for seven Bexar County, Texas invertebrate species

    Data.gov (United States)

    US Fish and Wildlife Service, Department of the Interior — To provide the user with a general idea of areas where final critical habitat for seven federally listed karst invertebrates occur in Bexar County, Texas.

  5. 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...

  6. South Florida Seagrass Fish and Invertebrate Assessment Network (FIAN)

    Data.gov (United States)

    U.S. Geological Survey, Department of the Interior — The South Florida Fish and Invertebrate Assessment Network (FIAN) is a monitoring project within the Comprehensive Everglades Restoration Plan (CERP). It is an...

  7. Invertebrate sampling at Fish Springs National Wildlife Refuge

    Data.gov (United States)

    US Fish and Wildlife Service, Department of the Interior — This document presents results from an invertebrate study conducted on Fish Springs National Wildlife Refuge. The purposes of this study were to: 1) quanitify...

  8. 76 FR 61379 - Final Recovery Plan, Bexar County Karst Invertebrates

    Science.gov (United States)

    2011-10-04

    ... Bexar County karst invertebrates were listed as endangered species on December 26, 2000 (65 FR 81419... cave clusters that represent the range of the species and potential genetic diversity for the...

  9. 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...

  10. Bristol Bay, Alaska Subarea 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 the Bristol Bay Subarea. The Subarea includes marine and...

  11. Determining detection sensitivity and methods for invertebrate sampling

    Science.gov (United States)

    This meeting is intended to communicate Great Lakes invasive species early detection science to state management agencies to assist them in implementing monitoring. My presentation summaries lessons learned concerning invertebrate monitoring in the course of ORD research on earl...

  12. Dynamics of Invertebrate Diversity in a Tropical Stream

    OpenAIRE

    Pearson, Richard G.

    2014-01-01

    Regional studies of biotic communities are important for characterising their normal spatial and temporal variation, but there are few such studies of tropical streams. This paper describes changes in invertebrate communities in Yuccabine Creek, a seasonal upland rainforest stream in tropical Australia, over three-year and decadal periods. Invertebrate abundance, richness and evenness were temporally stable, except after major drying or wet-season flows, from which they recovered quickly; how...

  13. A thesaurus for soil invertebrate trait-based approaches

    OpenAIRE

    Pey, Benjamin; Nahmani, Johanne; Auclerc, Apolline; Capowiez, Yvan; Caro, Gaël; Cluzeau, Daniel; Cortet, Jérôme; Decaëns, Thibaud; Dubs, Florence; Joimel, Sophie,; Guernion, Muriel; Briard, Charlène; Grumiaux, Fabien; Laporte, Baptiste; Pasquet, Alain

    2014-01-01

    Soil invertebrates are known to be much involved in soil behaviour and therefore in the provision of ecosystem services. Functional trait-based approaches are methodologies which can be used to understand soil invertebrates' responses to their environment. They (i) improve the predictions and (ii) are less dependent on space and time. The way traits have been used recently has led to misunderstandings in the integration and interpretation of data. Trait semantics are especially concerned. The...

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

    OpenAIRE

    Pisa, Lennard W.; Amaral-Rogers, Vanessa; Belzunces, Luc P.; Bonmatin, Jean-Marc; Downs, Craig A.; Goulson, Dave; Kreutzweiser, David P.; Christian H Krupke; Liess, Matthias; Melanie D McField; Morrissey, Christy A.; Noome, Dominique A.; Settele, Josef; Simon-Delso, Noa; Stark, John D.

    2014-01-01

    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 s...

  15. Key factors for the emergence of collective decision in invertebrates

    OpenAIRE

    VincentFourcassié

    2012-01-01

    In many species of group-living invertebrates, in particular arthropods, collective decisions can emerge from the combined actions of individuals and the direct or indirect interactions between individuals. These decisions allow groups of individuals to respond quickly and accurately to changes that occur in their environment. Examples of such decisions are found in a variety of invertebrate taxa and in many different contexts, e.g. exploring a new territory, foraging for food, finding a suit...

  16. Mephedrone ("bath salt") pharmacology: insights from invertebrates.

    Science.gov (United States)

    Ramoz, L; Lodi, S; Bhatt, P; Reitz, A B; Tallarida, C; Tallarida, R J; Raffa, R B; Rawls, S M

    2012-04-19

    Psychoactive bath salts (also called meph, drone, meow meow, m-CAT, bounce, bubbles, mad cow, etc.) contain a substance called mephedrone (4-methylcathinone) that may share psychostimulant properties with amphetamine and cocaine. However, there are only limited studies of the neuropharmacological profile of mephedrone. The present study used an established invertebrate (planarian) assay to test the hypothesis that acute and repeated mephedrone exposure produces psychostimulant-like behavioral effects. Acute mephedrone administration (50-1000 μM) produced stereotyped movements that were attenuated by a dopamine receptor antagonist (SCH 23390) (0.3 μM). Spontaneous discontinuation of mephedrone exposure (1, 10 μM) (60 min) resulted in an abstinence-induced withdrawal response (i.e. reduced motility). In place conditioning experiments, planarians in which mephedrone (100, 500 μM) was paired with the non-preferred environment during conditioning displayed a shift in preference upon subsequent testing. These results suggest that mephedrone produces three behavioral effects associated with psychostimulant drugs, namely dopamine-sensitive stereotyped movements, abstinence-induced withdrawal, and environmental place conditioning. PMID:22300981

  17. 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.

  18. Effects of plant-litter quality on litter decomposition by benthic invertebrates along a gradient of eutrophication

    OpenAIRE

    Pereira, Ana Maria Novais

    2011-01-01

    Os impactos humanos nos ecossistemas de água doce, como a eutrofização e as alterações na vegetação ripária, estão a aumentar, e os decisores políticos estão a fazer esforços para identificar as prioridades de gestão. Um ponto crítico é a avaliação da integridade ecológica dos ecossistemas. As comunidades de invertebrados bentónicos têm sido amplamente usadas para avaliar a condição estrutural dos rios, porque elas integram os efeitos dos stressores ao longo do tempo. Contudo, as medidas estr...

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

    Directory of Open Access Journals (Sweden)

    J. J. L. FONSECA

    1999-08-01

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

  20. Conservation and monitoring of invertebrates in terrestrial protected areas

    Directory of Open Access Journals (Sweden)

    Melodie A. McGeoch

    2011-05-01

    Full Text Available Invertebrates constitute a substantial proportion of terrestrial and freshwater biodiversity and are critical to ecosystem function. However, their inclusion in biodiversity monitoring and conservation planning and management has lagged behind better-known, more widely appreciated taxa. Significant progress in invertebrate surveys, systematics and bioindication, both globally and locally, means that their use in biodiversity monitoring and conservation is becoming increasingly feasible. Here we outline challenges and solutions to the integration of invertebrates into biodiversity management objectives and monitoring in protected areas in South Africa. We show that such integration is relevant and possible, and assess the relative suitability of seven key taxa in this context. Finally, we outline a series of recommendations for mainstreaming invertebrates in conservation planning, surveys and monitoring in and around protected areas.Conservation implications: Invertebrates constitute a substantial and functionally significant component of terrestrial biodiversity and are valuable indicators of environmental condition. Although consideration of invertebrates has historically been neglected in conservation planning and management, substantial progress with surveys, systematics and bioindication means that it is now both feasible and advisable to incorporate them into protected area monitoring activities.

  1. 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)

  2. Chemical elements in invertebrate orders for environmental quality studies

    International Nuclear Information System (INIS)

    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)

  3. Invertebrate communities of Nabugabo Lakes: a vital support resource for the fisheries and ecosystem diversity

    OpenAIRE

    Ndawula, L.M.; Kiggundu, V.; Pabire Ghandi, W.

    2005-01-01

    A field study of the invertebrate communities of the Nabugabo lakes(Nabugabo,Kayanja and Kayugi)showed the occurrence of copepoda, cladocera and rotifera(micro-invertebrates or zooplankton); Ephemeroptera and Diptera(macro-invertebrates or zoo-benthos). The most commonly encountered taxa were thermocyclops neglectus, moinamicrura,several rotiferan species(micro-invertebrates);P.adusta,chironomus, tanipodinae and trichoptera(macro- invertebrates). These organisms are assumed to be readily avai...

  4. Environmental Controls on River Assemblages at the Regional Scale: An Application of the Elements of Metacommunity Structure Framework.

    Directory of Open Access Journals (Sweden)

    Jonathan D Tonkin

    Full Text Available Understanding factors that structure regional biodiversity is important for linking ecological and biogeographic processes. Our objective was to explore regional patterns in riverine benthic invertebrate assemblages in relation to their broad positioning along the river network and examine differences in composition, biodiversity (alpha and beta diversity, and environmental drivers. We up-scaled methods used to examine patterns in metacommunity structure (Elements of Metacommunity Structure framework to examine faunal distribution patterns at the regional extent for 168 low-mountain stream invertebrate assemblages in central Germany. We then identified the most influential environmental factors using boosted regression trees. Faunal composition patterns were compartmentalised (Clementsian or quasi-Clementsian, with little difference from headwaters to large rivers, potentially reflecting the regional scale of the study, by crossing major catchment boundaries and incorporating different species pools. While idealised structures did not vary, environmental drivers of composition varied considerably between river sections and with alpha diversity. Prediction was substantially weaker, and the importance of space was greater, in large rivers compared to other sections suggesting a weakening in species sorting downstream. Further, there was a stronger transition in composition than for alpha diversity downstream. The stronger links with regional faunal composition than with richness further emphasises the importance of considering the alternative ways in which anthropogenic stressors are operating to affect biodiversity patterns. Our approach allowed bridging the gap between local (or metacommunity and regional scales, providing key insights into drivers of regional biodiversity patterns.

  5. Environmental Controls on River Assemblages at the Regional Scale: An Application of the Elements of Metacommunity Structure Framework.

    Science.gov (United States)

    Tonkin, Jonathan D; Sundermann, Andrea; Jähnig, Sonja C; Haase, Peter

    2015-01-01

    Understanding factors that structure regional biodiversity is important for linking ecological and biogeographic processes. Our objective was to explore regional patterns in riverine benthic invertebrate assemblages in relation to their broad positioning along the river network and examine differences in composition, biodiversity (alpha and beta diversity), and environmental drivers. We up-scaled methods used to examine patterns in metacommunity structure (Elements of Metacommunity Structure framework) to examine faunal distribution patterns at the regional extent for 168 low-mountain stream invertebrate assemblages in central Germany. We then identified the most influential environmental factors using boosted regression trees. Faunal composition patterns were compartmentalised (Clementsian or quasi-Clementsian), with little difference from headwaters to large rivers, potentially reflecting the regional scale of the study, by crossing major catchment boundaries and incorporating different species pools. While idealised structures did not vary, environmental drivers of composition varied considerably between river sections and with alpha diversity. Prediction was substantially weaker, and the importance of space was greater, in large rivers compared to other sections suggesting a weakening in species sorting downstream. Further, there was a stronger transition in composition than for alpha diversity downstream. The stronger links with regional faunal composition than with richness further emphasises the importance of considering the alternative ways in which anthropogenic stressors are operating to affect biodiversity patterns. Our approach allowed bridging the gap between local (or metacommunity) and regional scales, providing key insights into drivers of regional biodiversity patterns. PMID:26270550

  6. 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. PMID:24147405

  7. Size structure of a heavily fished benthic/demersal community by shrimp trawling in the Colombian Caribbean Sea Estructura de tamaños de una comunidad bentónica/demersal fuertemente impactada por la pesca de arrastre camaronero en el Mar Caribe de Colombia

    Directory of Open Access Journals (Sweden)

    Paúl Gómez-Canchong

    2011-01-01

    Full Text Available The benthic and demersal communities in the Colombian Caribbean Sea (CCS are heavily fished by the shrimp trawling fishery, which presents very high discard levels. Here, we conducted an analysis of the size structure of these benthic and demersal communities in the northern and southern zones of the CCS. Sampling was conducted onboard shrimp trawlers throughout an entire year. No significant differences were found in the size distributions of the two zones, among sites within southern ecoregions, or among the analyzed cruises. This homogeneity in size structure is remarkable since the zones analyzed possess very different species compositions and environmental conditions. The observed size structures were adequately described by non-linear distributions rather than the traditionally employed linear normalized biomass size spectra. It is hypothesized that the non-linearity is due to the effect of fishing and particularly, of discarding. This study emphasizes the need for a greater understanding of the impacts that trawl fishing has on community size structure and the applicability of this knowledge towards fishery resource management in ecosystems with high diversity.Las comunidades bentónico-demersales en el Mar Caribe de Colombia (MCC son fuertemente explotadas por la pesca de arrastre camaronero, presentando niveles de descarte muy altos. Se efectuó un análisis de la estructura de tamaños de estas comunidades bentónico-demersales en las zonas norte y sur del MCC. Se realizaron muéstreos a bordo de las embarcaciones de arrastre de camarón a lo largo de un año. No se encontraron diferencias significativas entre las distribuciones de tamaños de las diferentes zonas, ecorregiones de la zona sur y cruceros analizados. Esta homogeneidad en la estructura de tamaños es destacable ya que las areas analizadas difieren en composición de especies y condiciones medioambientales. Las estructuras de tamaño observadas, fueron descritas

  8. Influence of diking on the benthic macro-invertebrate communit y structure and diversity in the south bank of the Changjiang Estuary%围垦对长江口南岸底栖动物群落结构及多样性的影响

    Institute of Scientific and Technical Information of China (English)

    袁兴中; 陆健健

    2001-01-01

    通过对长江口南岸围垦潮滩和自然潮滩大型底栖无脊椎动物进行取样调查,研究了围垦潮滩的底栖动物群落结构及其多样性特征,分析了围垦对潮滩底栖动物群落结构及多样性的影响.研究发现:①围垦使底栖动物群落种类减少,种类组成发生变化;总趋势是,围垦以后,甲壳动物种类明显减少,由7 种减少到1种;随着围垦时间延长,多毛类种类减少,由4种减少到3种,直到最后消失;而软体动物和昆虫幼虫种类所占比例则明显增加,分别从占总种数的29.41%、5.89%增加到5 0.00%和25.00%;②围垦1a且仍受潮水影响的潮滩,底栖动物种类丰度虽有降低,但其密度和生物量却明显增加,分别从132.10个/m\\+2、35.31g/m\\+2(湿重)增加到218.32个/m +2和79.66 g/m\\+2(湿重);围垦2a且潮水不能进入的潮滩,底栖动物生物量大大降低,降到3.02 g/m\\+2(湿重);③围垦时间短且仍受潮水影响的潮滩与未围垦的自然潮滩相比,其底栖动物多样性降低不明显;围垦时间长且潮水不能进入的潮滩,底栖动物多样性明显降低 ,反映了围垦导致潮滩湿地生境退化;④围垦对底栖动物群落结构及多样性的影响,是通过改变潮滩湿地生境中的多种环境因子造成的,如潮滩高程、水动力、沉积物特性、植被演替等,是各种因子综合作用的结果.

  9. Effect of hypoxia and anoxia on invertebrate behaviour: ecological perspectives from species to community level

    Directory of Open Access Journals (Sweden)

    B. Riedel

    2013-08-01

    Full Text Available Coastal hypoxia and anoxia have become a global key stressor to marine ecosystems, with almost 500 dead zones recorded wordwide. By triggering cascading effects from the individual organism to the community and ecosystem-level, oxygen depletions threat marine biodiversity and can alter ecosystem structure and function. By integrating both physiological function and ecological processes, animal behaviour is ideal for assessing the stress state of benthic macrofauna to low dissolved oxygen. The initial response of organisms can serve as an early-warning signal, while the successive behavioural reactions of key species indicate hypoxia levels and help assess community degradation. Here we document the behavioural responses of a representative spectrum of benthic macrofauna in the natural setting in the Northern Adriatic Sea, Mediterranean. We experimentally induced small-scale anoxia with a benthic chamber in 24 m depth to overcome the difficulties in predicting the onset of hypoxia, which often hinders full documentation in the field. The behavioural reactions were documented with a time-lapse camera. Oxygen depletion elicited significant and repeatable changes in general (visibility, locomotion, body movement and posture, location and species-specific reactions in virtually all organisms (302 individuals from 32 species and 2 species groups. Most atypical (stress behaviours were associated with specific oxygen thresholds: arm-tipping in the ophiuroid Ophiothrix quinquemaculata, for example, with the onset of mild hypoxia (2 L−1, the emergence of polychates on the sediment surface with moderate hypoxia (2 L−1, the emergence of the infaunal sea urchin Schizaster canaliferus on the sediment with severe hypoxia (2 L−1 and heavy body rotations in sea anemones with anoxia. Other species changed their activity patterns, i.e. circadian rhythm in the hermit crab Paguristes eremita or the bioherm-associated crab Pisidia longimana. Intra- and

  10. A thesaurus for soil invertebrate trait-based approaches.

    Science.gov (United States)

    Pey, Benjamin; Laporte, Marie-Angélique; Nahmani, Johanne; Auclerc, Apolline; Capowiez, Yvan; Caro, Gaël; Cluzeau, Daniel; Cortet, Jérôme; Decaëns, Thibaud; Dubs, Florence; Joimel, Sophie; Guernion, Muriel; Briard, Charlène; Grumiaux, Fabien; Laporte, Baptiste; Pasquet, Alain; Pelosi, Céline; Pernin, Céline; Ponge, Jean-François; Salmon, Sandrine; Santorufo, Lucia; Hedde, Mickaël

    2014-01-01

    Soil invertebrates are known to be much involved in soil behaviour and therefore in the provision of ecosystem services. Functional trait-based approaches are methodologies which can be used to understand soil invertebrates' responses to their environment. They (i) improve the predictions and (ii) are less dependent on space and time. The way traits have been used recently has led to misunderstandings in the integration and interpretation of data. Trait semantics are especially concerned. The aim of this paper is to propose a thesaurus for soil invertebrate trait-based approaches. T-SITA, an Internet platform, is the first initiative to deal with the semantics of traits and ecological preferences for soil invertebrates. It reflects the agreement of a scientific expert community to fix semantic properties (e.g. definition) of approximately 100 traits and ecological preferences. In addition, T-SITA has been successfully linked with a fully operational database of soil invertebrate traits. Such a link enhances data integration and improves the scientific integrity of data. PMID:25310431

  11. A thesaurus for soil invertebrate trait-based approaches.

    Directory of Open Access Journals (Sweden)

    Benjamin Pey

    Full Text Available Soil invertebrates are known to be much involved in soil behaviour and therefore in the provision of ecosystem services. Functional trait-based approaches are methodologies which can be used to understand soil invertebrates' responses to their environment. They (i improve the predictions and (ii are less dependent on space and time. The way traits have been used recently has led to misunderstandings in the integration and interpretation of data. Trait semantics are especially concerned. The aim of this paper is to propose a thesaurus for soil invertebrate trait-based approaches. T-SITA, an Internet platform, is the first initiative to deal with the semantics of traits and ecological preferences for soil invertebrates. It reflects the agreement of a scientific expert community to fix semantic properties (e.g. definition of approximately 100 traits and ecological preferences. In addition, T-SITA has been successfully linked with a fully operational database of soil invertebrate traits. Such a link enhances data integration and improves the scientific integrity of data.

  12. Chemosynthetic trophic support for the benthic community at an intertidal cold seep site at Mocha Island off central Chile

    Science.gov (United States)

    Sellanes, Javier; Zapata-Hernández, Germán; Pantoja, Silvio; Jessen, Gerdhard L.

    2011-12-01

    We analyzed C and N stable isotope ratios of benthic fauna and their potential food sources at an intertidal methane seep site and a control site without emanation at Mocha Island (central Chile). The objective was to trace the origin of the main food sources used by the local heterotrophic fauna, based on the hypothesis that chemosynthetic production could be partially fueling the local food web at the seep site. Food sources sampled at both sites included macroalgae, particulate organic matter and bacteria-like filaments found growing over the red algae Gelidium lingulatum within the areas of active methane release. At the control site, located 11 km away from the gas emanation, fauna exhibited moderate δ 13C values ranging from -16.2‰ (in a nereid polychaete) to -14.8‰ (in a cirolanid isopod), which were consistent with those of the potential photosynthetic food sources sampled at this site (-20.2 to -16.5‰). δ 13C values of the photosynthetic food sources at the seep site similarly ranged between -25.4 and -17.9‰. However, a portion of the animals at this site were consistently more 13C-depleted, with δ 13C values close to that of the seeping methane (-43.8‰) and the bacteria-like filaments (-39.2 ± 2.5‰) also collected at this site. Specific examples were the Marphysa sp. polychaetes (δ 13C = -44.7 ± 0.6‰), the Schistomeringos sp. dorvilleid polychaetes (δ 13C = -42.9‰), and the tanaid crustacean Zeuxo marmoratus (δ 13C = -37.3 ± 0.2‰). The significantly higher δ 13C values of the herbivorous gastropod Tegula atra at the seep site (-29.3 ± 3.1‰) than at the control site (-12.6 ± 0.3‰) also indicated differences among sites of the preferred carbon sources of this species. Mixing model estimates indicate that at the seep site bacteria-like filaments could be contributing up to ˜60% of the assimilated diet of selected invertebrates. Furthermore, several indicators of trophic structure, based in isotopic niche metrics, indicate a

  13. The truth is out there: measured, calculated and modelled benthic fluxes.

    Science.gov (United States)

    Pakhomova, Svetlana; Protsenko, Elizaveta

    2016-04-01

    In a modern Earth science there is a great importance of understanding the processes, forming the benthic fluxes as one of element sources or sinks to or from the water body, which affects the elements balance in the water system. There are several ways to assess benthic fluxes and here we try to compare the results obtained by chamber experiments, calculated from porewater distributions and simulated with model. Benthic fluxes of dissolved elements (oxygen, nitrogen species, phosphate, silicate, alkalinity, iron and manganese species) were studied in the Baltic and Black Seas from 2000 to 2005. Fluxes were measured in situ using chamber incubations (Jch) and at the same time sediment cores were collected to assess the porewater distribution at different depths to calculate diffusive fluxes (Jpw). Model study was carried out with benthic-pelagic biogeochemical model BROM (O-N-P-Si-C-S-Mn-Fe redox model). It was applied to simulate biogeochemical structure of the water column and upper sediment and to assess the vertical fluxes (Jmd). By the behaviour at the water-sediment interface all studied elements can be divided into three groups: (1) elements which benthic fluxes are determined by the concentrations gradient only (Si, Mn), (2) elements which fluxes depend on redox conditions in the bottom water (Fe, PO4, NH4), and (3) elements which fluxes are strongly connected with organic matter fate (O2, Alk, NH4). For the first group it was found that measured fluxes are always higher than calculated diffusive fluxes (1.5changing redox conditions some processes in the bottom water and/or on the sediment surface (oxidation, adsorption, particles dissolution, etc.) are faster than diffusion and play an important role in the benthic flux formation for these elements. For the third group measured fluxes could be often overestimated, especially for coastal shallow stations, up to 50%, because of intensive decomposition of OM and/or organisms respiration in the isolated bottom

  14. Molecular mechanisms of heavy metal tolerance and evolution n invertebrates

    Institute of Scientific and Technical Information of China (English)

    Thierry K.S.Janssens; Dick Roelofs; Nico M.van Straalen

    2009-01-01

    Following the genomics revolution,our knowledge of the molecular mechanisms underlying defenses against stress has been greatly expanded.Under strong selective pressure many animals may evolve an enhanced stress tolerance.This can be achieved by altering the structure of proteins(through mutations in the coding regions of genes)or by altering the amount of protein(through changes in transcriptional regulation).The latter type of evolution Can be achieved by substitutions in the promoter of the gene of interest(cis-regulatory change)or by altering the structure or anaount of transcriptional regulator proteins (trans-regulatory change).The metallothionein system is one of the best studied stress response systems in the context of heavy metals.Metallothionein expression is assumed to be regulated by metal transcription factor 1(MTF-1);however,up to now the involvement of MTF-1 has only been proven for some vertebrates and Drosophila.Data on invertebrates such as nematodes and earthworms suggest that other mechanisms of metallothionein induction may be present.A detailed study of Cd tolerance was done for a species of soilliving springtail,Orchesella cincta.The metallothionein gene of this species is overexpressed in metal-exposed field populations.Analysis of the metallothionein promoter has demonstrated extensive polymorphisills that have a functional significance,as shown in bioreporter assays.In a study comparing 20 different populations,the frequency of a high-expresser promoter allele Was positively correlated with the concentration of metals in soil,especially Cd.The springtail study shows that cis-regulatory change of genes involved in the cellular stress response may contribute to evolution of metal tolerance.

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

    Energy Technology Data Exchange (ETDEWEB)

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

    2011-01-01

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

  16. Benthic macroinvertebrates in Italian rice fields

    Directory of Open Access Journals (Sweden)

    Daniela Lupi

    2013-02-01

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

  17. Genetic effects of tank-forming bromeliads on the associated invertebrate community in a tropical forest ecosystem.

    Science.gov (United States)

    Zytynska, Sharon E; Khudr, Mouhammad Shadi; Harris, Edwin; Preziosi, Richard F

    2012-10-01

    Within the area of community genetics there is an expanding volume of literature demonstrating how within-species genetic variation in temperate trees can have important effects on structuring animal and plant communities. The influence of intraspecific genetic variation on associated communities in relatively more complex ecosystems is only starting to be appreciated. Within tropical forests, epiphytic bromeliad plants often grow high in the canopy and create unique nutrient-rich microhabitats on which many invertebrate and vertebrate species depend. We investigated the influence of within-species genetic variation in the bromeliad Aechmea bracteata on the invertebrate microhabitat community. We found that more genetically similar bromeliad plants were host to more similar communities of juvenile-stage invertebrates, but not adult invertebrates. We discuss possible mechanisms for this, including differential survival and active female oviposition choice. Our work shows that the impact of within-species genetic variation on associated ecological communities may be more general than previously considered. These results agree with recent research suggesting that within-species genetic variation may perform a supporting ecosystem service for maintaining community and ecological processes. PMID:22466862

  18. 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.

  19. 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. PMID:23001759

  20. Benthic ecosystem functioning in the severely contaminated Mar Piccolo of Taranto (Ionian Sea, Italy): focus on heterotrophic pathways.

    Science.gov (United States)

    Franzo, A; Auriemma, R; Nasi, F; Vojvoda, J; Pallavicini, A; Cibic, T; Del Negro, P

    2016-07-01

    The benthic ecosystem functioning is a rarely applied holistic approach that integrates the main chemical and biological features of the benthic domain with the key processes responsible for the flux of energy and C through the system. For the first time, such conceptual model, with an emphasis on the heterotrophic pathways, has been applied to the sediments at four stations within one of the most polluted coastal areas in Italy: the Mar Piccolo of Taranto. The functioning of the benthic ecosystem was different according to the investigated site. Nearby the military arsenal, i.e., the main source of organic contaminants and heavy metals, the system seemed inhibited at all the investigated structural and functional levels. Slow microbial processes of C reworking together with very limited densities of benthic fauna suggested a modest transfer of C both into a solid microbial loop and to the higher trophic levels. On the other hand, the ingression of marine water through the "Navigabile" channel seemed to stimulate the organic matter degradation and, consequently, the proliferation of meiofauna and macrofauna. In the innermost part of the basin, the system functioning, to some extent, is less impacted by contaminants and more influenced by mussel farms. The organic matter produced by these bivalves fueled faster C reworking by benthic prokaryotes and enhanced the proliferation of filter feeders. PMID:26370810