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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)

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

    2009-01-01

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

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

    Energy Technology Data Exchange (ETDEWEB)

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

    2009-08-15

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

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

    African Journals Online (AJOL)

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

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

    Science.gov (United States)

    Frelik, Anna; Pakulnicka, Joanna

    2015-10-01

    This paper investigates the relations between the diet structure of predaceous adult water beetles from the Dytiscidae family and the structure of macrofauna inhabiting the same environments. The field studies were carried out from April until September in 2012 and 2013 in 1-mo intervals. In total, >1,000 water beetles and 5,115 benthic macro-invertebrates were collected during the whole period of the study. Subsequently, 784 specimens of adult water beetles (70.6% out of the total sampled) with benthic macro-invertebrates found in their proventriculi, were subject to analysis. The predators were divided into three categories depending on their body size: small beetles (2.3-5.0 mm), medium-sized beetles (13-15 mm), and large beetles (27-37 mm). All adult Dytiscidae consumed primarily Ephemeroptera and Chironomidae larvae. Although Asellidae were numerically dominant inhabitants of the sites, the adult water beetles did not feed on them. The analysis of feeding relations between predators and their prey revealed that abundance of Ephemeroptera, Chironomidae, and larval Dytiscidae between the environment and the diet of adult Dytiscidae were strongly correlated. © The Authors 2015. Published by Oxford University Press on behalf of Entomological Society of America. All rights reserved. For Permissions, please email: journals.permissions@oup.com.

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

    African Journals Online (AJOL)

    Mo

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

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

    Science.gov (United States)

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

    2010-01-01

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

  8. Regulation of nitrous oxide emission associated with benthic invertebrates

    DEFF Research Database (Denmark)

    Stief, Peter; Schramm, Andreas

    2010-01-01

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

  9. Distribution pattern of benthic invertebrates in Danish estuaries

    DEFF Research Database (Denmark)

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

    2013-01-01

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

  10. Do lake littoral benthic invertebrates respond differently to eutrophication, hydromorphological alteration, land use and fish stocking?

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    Šiling Rebeka

    2016-01-01

    Full Text Available In order to provide adequate guidelines in freshwater management, managers need reliable bioindicators that can respond differently to varied stressors. Managers also have to consider hierarchical structure of environmental factors. Thus, our research aims to test the independence of taxa responses along environmental gradients and to examine in what order natural and anthropogenic factors constrain the structure of littoral benthic assemblages. The rank of explained variance of littoral benthic assemblage's variable group hierarchy was: land use > landscape characteristics > eutrophication > fish stocking > hydromorphological alteration. We determined nine gradients (two natural and seven stressor gradients, separated into five groups based on statistically significant differences in responsiveness of taxa. Apart from responsiveness to natural factors, littoral benthic invertebrates could be used as bioindicators for stressors reflecting urbanization, eutrophication, hydromorphological alteration and fish stocking. The taxonomical composition of littoral benthic invertebrates, especially when taxa with preference for certain relatively narrow environmental conditions along gradients are present, can be used to identify effects of key stressors. Our findings have profound implications for ecological assessment and management of lakes, as they indicate that benthic invertebrates can be used when the effects of multiple stressors need to be disentangled.

  11. Early invasion population structure of quagga mussel and associated benthic invertebrate community composition on soft sediment in a large reservoir

    Science.gov (United States)

    Wittmann, Marion E.; Chandra, Sudeep; Caires, Andrea; Denton, Marianne; Rosen, Michael R.; Wong, Wai Hing; Teitjen, Todd; Turner, Kent; Roefer, Peggy; Holdren, G. Chris

    2010-01-01

    In 2007 an invasive dreissenid mussel species, Dreissena bugensis (quagga mussel), was discovered in Lake Mead reservoir (AZ–NV). Within 2 years, adult populations have spread throughout the lake and are not only colonizing hard substrates, but also establishing in soft sediments at depths ranging from 1 to >100 m. Dreissena bugensis size class and population density distribution differs between basins; cluster analysis revealed 5 adult cohorts within Boulder Basin and Overton Arm but low densities and low cohort survival in the Las Vegas Basin. Regression analysis suggests depth and temperature are not primary controllers of D. bugensis density in Lake Mead, indicating other factors such as sediment type, food availability or other resource competition may be important. Monthly veliger tows showed at least 2 major spawning events per year, with continuous presence of veligers in the water column. Adult mussels have been found in spawn or post-spawn condition in soft sediments in shallow to deep waters (>80 m) indicating the potential for reproduction at multiple depths. Comparisons to a 1986 benthic survey suggest there have been shifts in nondreissenid macroinvertebrate composition; however, it is unclear if this is due to D. bugensis presence. Current distribution of nondreissenid macroinvertebrates is heterogeneous in all 3 basins, and their biodiversity decreased when D. bugensis density was 2500/m2 or greater.

  12. 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

  13. Impact of morpho-hydraulic structure of small flows river-basins for settlement by benthic invertebrate

    International Nuclear Information System (INIS)

    Pastuchova, Z.

    2009-01-01

    We examined two types of potential habitat for macrozoobenthos: 1 morphological units; 2 types of flow as a complex of hydraulic characteristics of habitat. Both types of habitats were analyzed by their physical attributes and macroinvertebrate communities. Froude (Fr) and Reynolds (Re) number turned out to be suitable as a descriptor of the average hydraulic habitat conditions. The structure of the communities involved abundance, food types, substrate, saprobic and current preferences. From directly measured variables the most significant effect had the flow velocity. (author)

  14. Procedures for radioecological studies with marine benthic invertebrates

    International Nuclear Information System (INIS)

    Vilquin, A.; Fowler, S.W.; Renfro, W.C.

    1975-01-01

    Methods for the collection, transportation, and pre-experimental handling are briefly described. In designing radioecological experiments on marine benthic invertebrates it is important to prevent overcrowding and to choose healthy, well-acclimated animals. Feeding of the animals and presence or absence of sediments in the aquaria are critical variables in many experiments. Length of time the experiment is run and interim growth of the experimental animals may result in significant variability in results. The physico-chemical form of the radiotracer is another important experimental variable. (author)

  15. Procedures for Radioecological Studies with Marine Benthic Invertebrates

    International Nuclear Information System (INIS)

    Vilquin, A.; Fowler, S.W.; Renfro, W.C.

    1976-01-01

    Methods for the collection transportation, and pre-experimental handling are briefly described. In designing radioecological experiments on marine benthic invertebrates it is important to prevent overcrowding and to choose healthy, well-acclimated animals. Feeding of the animals and presence or absence of sediments in the aquaria are critical variables in many experiments. Length of time the experiment is run and interim growth of the experimental animals may result in significant variability in results. The physico-chemical form of the radiotracer is another important experimental variable. (author)

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

    Science.gov (United States)

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

    2018-01-01

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

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

    Science.gov (United States)

    Lindquist, Niels

    2002-10-01

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

  18. Chemoreception of the Seagrass Posidonia Oceanica by Benthic Invertebrates is Altered by Seawater Acidification.

    Science.gov (United States)

    Zupo, Valerio; Maibam, Chingoileima; Buia, Maria Cristina; Gambi, Maria Cristina; Patti, Francesco Paolo; Scipione, Maria Beatrice; Lorenti, Maurizio; Fink, Patrick

    2015-08-01

    Several plants and invertebrates interact and communicate by means of volatile organic compounds (VOCs). These compounds may play the role of infochemicals, being able to carry complex information to selected species, thus mediating inter- or intra-specific communications. Volatile organic compounds derived from the wounding of marine diatoms, for example, carry information for several benthic and planktonic invertebrates. Although the ecological importance of VOCs has been demonstrated, both in terrestrial plants and in marine microalgae, their role as infochemicals has not been demonstrated in seagrasses. In addition, benthic communities, even the most complex and resilient, as those associated to seagrass meadows, are affected by ocean acidification at various levels. Therefore, the acidification of oceans could produce interference in the way seagrass-associated invertebrates recognize and choose their specific environments. We simulated the wounding of Posidonia oceanica leaves collected at two sites (a control site at normal pH, and a naturally acidified site) off the Island of Ischia (Gulf of Naples, Italy). We extracted the VOCs and tested a set of 13 species of associated invertebrates for their specific chemotactic responses in order to determine if: a) seagrasses produce VOCs playing the role of infochemicals, and b) their effects can be altered by seawater pH. Our results indicate that several invertebrates recognize the odor of wounded P. oceanica leaves, especially those strictly associated to the leaf stratum of the seagrass. Their chemotactic reactions may be modulated by the seawater pH, thus impairing the chemical communications in seagrass-associated communities in acidified conditions. In fact, 54% of the tested species exhibited a changed behavioral response in acidified waters (pH 7.7). Furthermore, the differences observed in the abundance of invertebrates, in natural vs. acidified field conditions, are in agreement with these behavioral

  19. Functional roles of an engineer species for coastal benthic invertebrates and demersal fish.

    Science.gov (United States)

    Chaalali, Aurélie; Brind'Amour, Anik; Dubois, Stanislas F; Le Bris, Hervé

    2017-08-01

    Through their tissues or activities, engineer species create, modify, or maintain habitats and alter the distribution and abundance of many plants and animals. This study investigates key ecological functions performed by an engineer species that colonizes coastal ecosystems. The gregarious tubiculous amphipod Haploops nirae is used as a biological model. According to previous studies, the habitat engineered by H. nirae (i.e., Haploops habitat) could provide food and natural shelter for several benthic species such as benthic diatoms belonging to the gender Navicula , the micrograzer Geitodoris planata, or the bivalve Polititapes virgineus . Using data from scientific surveys conducted in two bays, this study explored whether (1) the Haploops sandy-mud community modifies invertebrate and ichthyologic community structure (diversity and biomass); (2) H. nirae creates a preferential feeding ground; and (3) this habitat serves as a refuge for juvenile fish. Available Benthic Energy Coefficients, coupled with more traditional diversity indices, indicated higher energy available in Haploops habitat than in two nearby habitats (i.e., Sternaspis scutata and Amphiura filiformis/Owenia fusiformis habitats). The use of isotopic functional indices (IFIs) indicated (1) a higher functional richness in the Haploops habitat, related to greater diversity in food sources and longer food chains; and (2) a higher functional divergence, associated with greater consumption of a secondary food source. At the invertebrate-prey level, IFIs indicated little specialization and little trophic redundancy in the engineered habitat, as expected for homogenous habitats. Our results partly support empirical knowledge about engineered versus nonengineered habitats and also add new perspectives on habitat use by fish and invertebrate species. Our analyses validated the refuge-area hypothesis for a few fish species. Although unique benthic prey assemblages are associated with Haploops habitat, the

  20. 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.

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

    Science.gov (United States)

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

    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 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. PMID:25535973

  2. A cross-continental comparison of the effects of flow intermittence on benthic invertebrate assemblages

    Science.gov (United States)

    Although temporary rivers are widespread freshwater systems, they have been poorly studied by ecologists and are largely ignored in water management plans, practices and policies. If the effects of dry events on benthic invertebrates have been reported individually from different...

  3. Six decades of change in pollution and benthic invertebrate biodiversity in a southern New England estuary

    Science.gov (United States)

    Pollution has led to a decline of benthic invertebrate biodiversity of Narragansett Bay, raising questions about effects on ecosystem functions and services including shellfish production, energy flow to fishes, and biogeochemical cycles. Changes in community composition and taxo...

  4. 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...

  5. Experimental studies on californium bioavailability to marine benthic invertebrates

    International Nuclear Information System (INIS)

    Fowler, S.W.; Carvalho, F.P.; Aston, S.R.

    1986-01-01

    252 Cf is readily taken up by benthic invertebrates from sea water, reaching whole-body concentration factors of 763 in the polychaete Hermione hystrix, 220 in the shrimp Lysmata seticaudata, 665 in the crab Pilumnus hirtellus and 78 in the bivalve mollusc Venerupis decussata after 3 weeks exposure. Surface sorption plays a predominant role in the uptake process. Depuration in clean sea water was a relatively slow process. The shrimp Lysmata eliminated 252 Cf very rapidly due to moulting. Absorption coefficients for ingested 252 Cf were high, approx. 23% in crabs and approx. 97% in brittlestars. The absorbed fraction was excreted twice as fast from crabs as brittlestars. Exposure of organisms to labelled sediment resulted in low transfer factors that were species dependent. There is some evidence to suggest that uptake from sediments is primarily due to 252 Cf transfer from the pore water. Comparison of these results with published experimental data on other transuranic nuclides in the same or similar species suggests that californium bioavailability is roughly equivalent to that of plutonium and americium. (author)

  6. Influence of environmental factors on the benthic invertebrates community distribution in channels of a neotropical floodplain

    Directory of Open Access Journals (Sweden)

    Danielle Katharine Petsch

    2013-09-01

    Full Text Available One of the central themes in ecology is the relative importance of local and regional processes for determining the communities’ structure, since both processes may behave as filters in the composition of local communities. Thus, this study analyzed the influence of environmental factors on the benthic invertebrate community distribution in different channels of the Upper Paraná River floodplain, through quarterly samplings conducted from March to December 2010. Through the biotic and abiotic data, we performed a Canonical Correspondence Analysis, where it was possible to visualize the centers of Ivinhema and Paraná rivers and Ipoitã channel separate from other points by high values of depth and velocity and taxa typical of lotic environments, such as Harpacticoida, Haplotaxidae, and Narapidae, and the center of the Curutuba channel, with L. fortunei. One may conclude that flow velocity, granulometric texture, and sediment organic matter were structuring factors of the benthic community, determining the distribution of invertebrates both among the various channels and between the marginal and central regions in these environments, providing greater or lesser availability of resources and environmental heterogeneity.

  7. Predictive models of benthic invertebrate methylmercury in Ontario and Quebec lakes

    Energy Technology Data Exchange (ETDEWEB)

    Rennie, M.D.; Collins, N.C.; Purchase, C.F. [Toronto Univ., ON (Canada). Dept. of Biology; Tremblay, A. [Hydro-Quebec, Montreal, PQ (Canada)

    2005-12-01

    In both North America and Europe, high levels of mercury have been reported in lakes that do not receive obvious point-source mercury inputs. Concern over high contaminant levels in waterfowl and fish have prompted several government-issued advisories on safe levels of fish and wildlife intake for humans. Although the primary source of mercury in pristine lakes is directly through atmospheric deposition or indirectly via terrestrial runoff, there can be large variations in mercury concentrations in organisms in neighbouring lakes. Therefore, factors other than atmospheric deposition must influence bioavailability and accumulation of mercury in aquatic organisms. For that reason, multivariate analyses on benthic invertebrate methylmercury concentrations and water chemistry from 12 Quebec water bodies were used to construct simple, predictive models of benthic invertebrate methylmercury in 23 lakes in Ontario and Quebec. The study showed that the primary means of mercury accumulation for organisms in higher trophic positions is dietary through the assimilation of organic forms of mercury, principally methylmercury. The data from 12 Quebec water bodies, revealed that benthic invertebrates in reservoirs have higher methylmercury than those in natural lakes, and methylmercury is generally higher in predatory invertebrates. Reservoir age was found to correlate with fish, benthic invertebrate methylmercury, and also with lake chemistry parameters such as pH and dissolved organic carbon (DOC). The objective of the study was to determine the appropriate level of taxonomic or functional resolution for generating benthic invertebrate methylmercury models, and to identify which environmental variables correlate most with benthic invertebrate methylmercury. Empirical models using these correlations were constructed and their predicted efficiency was tested by cross-validation. In addition, the effect of exposure to fish digestive enzymes on invertebrate methylmercury was

  8. 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

  9. Effects of Karenia brevis on clearance rates and bioaccumulation of brevetoxins in benthic suspension feeding invertebrates.

    Science.gov (United States)

    Echevarria, Michael; Naar, Jerome P; Tomas, Carmelo; Pawlik, Joseph R

    2012-01-15

    Blooms of the toxic alga Karenia brevis occur along coastlines where sessile suspension feeding invertebrates are common components of benthic communities. We studied the effects of K. brevis on four benthic suspension feeding invertebrates common to the coast of the SE United States: the sponge Haliclona tubifera, the bryozoan Bugula neritina, the bivalve Mercenaria mercenaria, and the tunicate Styela plicata. In controlled laboratory experiments, we determined the rate at which K. brevis was cleared from the seawater by these invertebrates, the effect of K. brevis on clearance rates of a non-toxic phytoplankton species, Rhodomonas sp., and the extent to which brevetoxins bioaccumulated in tissues of invertebrates using an enzyme-linked immunosorbent assay (ELISA). All four invertebrate species cleared significant quantities of K. brevis from seawater, with mean clearance rates ranging from 2.27 to 6.71 L g h⁻¹ for H. tubifera and S. plicata, respectively. In the presence of K. brevis, clearance rates of Rhodomonas sp. by B. neritina and S. plicata were depressed by 75% and 69%, respectively, while clearance rates by H. tubifera and M. mercenaria were unaffected. Negative effects of K. brevis were impermanent; after a recovery period of 13 h, B. neritina and S. plicata regained normal clearance rates. All four invertebrates accumulated high concentrations of brevetoxin after a 4h exposure to K. brevis, but when animals were transferred to filtered seawater for 15 h after exposure, brevetoxin concentrations in the tissues of H. tubifera and B. neritina decreased by ∼80%, while there was no change in toxin concentration in the tissues of S. plicata and M. mercenaria. High cell concentrations of K. brevis may cause a suppression of clearance rates in benthic suspension feeding invertebrates, resulting in a positive feedback for bloom formation. Also, high concentrations of toxin may accumulate in the tissues of benthic suspension feeding invertebrates that may

  10. 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...

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

    Energy Technology Data Exchange (ETDEWEB)

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

    2008-05-15

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

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

    International Nuclear Information System (INIS)

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

    2008-01-01

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

  13. Application of TSL Underwater Robots (AUV) for Investigation of Benthic Ecosystems and Quantification of Benthic Invertebrate Reserves

    Science.gov (United States)

    Golikov, S. Yu; Dulepov, V. I.; Maiorov, I. S.

    2017-11-01

    The issues on the application of autonomous underwater vehicles for assessing the abundance, biomass, distribution and reserves of invertebrates in the marine benthic ecosystems and on the environmental monitoring are discussed. An example of the application of methodology to assess some of the quantitative characteristics of macrobenthos is provided based upon using the information obtained from the TSL AUV in the Peter the Great Gulf (the Sea of Japan) in the Bay of Paris and the Eastern Bosphorus Strait within the area of the bridge leading to the Russian island. For the quantitative determination of the benthic invertebrate reserves, the values of biomass density of specific species are determined. Based on the data of direct measurements and weightings, the equations of weight dependencies on the size of animals are estimated according to the studied species that are well described by the power law dependence.

  14. Phylogenetically diverse macrophyte community promotes species diversity of mobile epi-benthic invertebrates

    Science.gov (United States)

    Nakamoto, Kenta; Hayakawa, Jun; Kawamura, Tomohiko; Kodama, Masafumi; Yamada, Hideaki; Kitagawa, Takashi; Watanabe, Yoshiro

    2018-07-01

    Various aspects of plant diversity such as species diversity and phylogenetic diversity enhance the species diversity of associated animals in terrestrial systems. In marine systems, however, the effects of macrophyte diversity on the species diversity of associated animals have received little attention. Here, we sampled in a subtropical seagrass-seaweed mixed bed to elucidate the effect of the macrophyte phylogenetic diversity based on the taxonomic relatedness as well as the macrophyte species diversity on species diversity of mobile epi-benthic invertebrates. Using regression analyses for each macrophyte parameter as well as multiple regression analyses, we found that the macrophyte phylogenetic diversity (taxonomic diversity index: Delta) positively influenced the invertebrate species richness and diversity index (H‧). Although the macrophyte species richness and H‧ also positively influenced the invertebrate species richness, the best fit model for invertebrate species richness did not include them, suggesting that the macrophyte species diversity indirectly influenced invertebrate species diversity. Possible explanations of the effects of macrophyte Delta on the invertebrate species diversity were the niche complementarity effect and the selection effect. This is the first study which demonstrates that macrophyte phylogenetic diversity has a strong effect on the species diversity of mobile epi-benthic invertebrates.

  15. 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...

  16. 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

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

    International Nuclear Information System (INIS)

    Kumblad, L.; Bradshaw, C.; Giled, M.

    2004-01-01

    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)

  18. The importance of spatial variation of benthic invertebrates for the ecological assessment of European lakes

    DEFF Research Database (Denmark)

    Solimini, Angelo G.; Sandin, Leif Leonard

    2012-01-01

    variability. However, littoral and profundal invertebrate communities are constrained by different drivers of change and may respond unevenly to distinct human disturbances. How human disturbances determined by different pressures interact in modifying the distribution of benthic invertebrate species......, funded by the European Union under the 7th Framework Programme), we collated several case studies with the aim to increase our understanding of basic sources of spatial variation of invertebrate assemblages. The set of papers includes a variety of different European lakes, habitat types and human...... pressures from the Nordic, Central, Atlantic, Alpine and Mediterranean regions. All papers have an obvious applied objective and suggest which factors need to be considered when designing invertebrate-based classification tools....

  19. Benthic invertebrate density, biomass, and instantaneous secondary production along a fifth-order human-impacted tropical river.

    Science.gov (United States)

    Aguiar, Anna Carolina Fornero; Gücker, Björn; Brauns, Mario; Hille, Sandra; Boëchat, Iola Gonçalves

    2015-07-01

    The aim of this study was to assess land use effects on the density, biomass, and instantaneous secondary production (IP) of benthic invertebrates in a fifth-order tropical river. Invertebrates were sampled at 11 stations along the Rio das Mortes (upper Rio Grande, Southeast Brazil) in the dry and the rainy season 2010/2011. Invertebrates were counted, determined, and measured to estimate their density, biomass, and IP. Water chemical characteristics, sediment heterogeneity, and habitat structural integrity were assessed in parallel. Total invertebrate density, biomass, and IP were higher in the dry season than those in the rainy season, but did not differ significantly among sampling stations along the river. However, taxon-specific density, biomass, and IP differed similarly among sampling stations along the river and between seasons, suggesting that these metrics had the same bioindication potential. Variability in density, biomass, and IP was mainly explained by seasonality and the percentage of sandy sediment in the riverbed, and not directly by urban or agricultural land use. Our results suggest that the consistently high degradation status of the river, observed from its headwaters to mouth, weakened the response of the invertebrate community to specific land use impacts, so that only local habitat characteristics and seasonality exerted effects.

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

    KAUST Repository

    Chandramouli, Kondethimmanahalli; Zhang, Yu; Wong, Yue Him; Qian, Pei Yuan

    2012-01-01

    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

  1. Species Sorting of Benthic Invertebrates in a Salinity Gradient – Importance of Dispersal Limitation

    Science.gov (United States)

    Josefson, Alf B.

    2016-01-01

    The relative importance of environment and dispersal related processes for community assembly has attracted great interest over recent decades, but few empirical studies from the marine/estuarine realm have examined the possible effects of these two types of factors in the same system. Importance of these processes was investigated in a hypothetical metacommunity of benthic invertebrates in 16 micro-tidal estuaries connected to the same open sea area. The estuaries differed in size and connectivity to the open sea and represented a salinity gradient across the estuaries. The Elements of Metacommunity Structure (EMS) approach on estuary scale was complemented with a mechanistic variance partitioning approach on sample scale to disentangle effects of factors affecting assembly of three trait groups of species with different dispersivity. A quasi-Clementsian pattern was observed for all three traits, a likely response to some latent gradient. The primary axis in the pattern was most strongly related to gradients in estuary salinity and estuary entrance width and correlation with richness indicated nestedness only in the matrix of the most dispersive trait group. In the variance partitioning approach measures of turnover and nestedness between paired samples each from different estuaries were related to environmental distance in different gradients. Distance between estuaries was unimportant suggesting importance of factors characterizing the estuaries. While the high dispersive species mainly were sorted in the salinity gradient, apparently according to their tolerance ranges towards salinity, the two less dispersive traits were additionally affected by estuary entrance width and possibly also area. The results exemplify a mechanism of community assembly in the marine realm where the niche factor salinity in conjunction with differential dispersal structure invertebrates in a metacommunity of connected estuaries, and support the idea that dispersive species are more

  2. Species Sorting of Benthic Invertebrates in a Salinity Gradient - Importance of Dispersal Limitation.

    Directory of Open Access Journals (Sweden)

    Alf B Josefson

    Full Text Available The relative importance of environment and dispersal related processes for community assembly has attracted great interest over recent decades, but few empirical studies from the marine/estuarine realm have examined the possible effects of these two types of factors in the same system. Importance of these processes was investigated in a hypothetical metacommunity of benthic invertebrates in 16 micro-tidal estuaries connected to the same open sea area. The estuaries differed in size and connectivity to the open sea and represented a salinity gradient across the estuaries. The Elements of Metacommunity Structure (EMS approach on estuary scale was complemented with a mechanistic variance partitioning approach on sample scale to disentangle effects of factors affecting assembly of three trait groups of species with different dispersivity. A quasi-Clementsian pattern was observed for all three traits, a likely response to some latent gradient. The primary axis in the pattern was most strongly related to gradients in estuary salinity and estuary entrance width and correlation with richness indicated nestedness only in the matrix of the most dispersive trait group. In the variance partitioning approach measures of turnover and nestedness between paired samples each from different estuaries were related to environmental distance in different gradients. Distance between estuaries was unimportant suggesting importance of factors characterizing the estuaries. While the high dispersive species mainly were sorted in the salinity gradient, apparently according to their tolerance ranges towards salinity, the two less dispersive traits were additionally affected by estuary entrance width and possibly also area. The results exemplify a mechanism of community assembly in the marine realm where the niche factor salinity in conjunction with differential dispersal structure invertebrates in a metacommunity of connected estuaries, and support the idea that dispersive

  3. Species Sorting of Benthic Invertebrates in a Salinity Gradient - Importance of Dispersal Limitation.

    Science.gov (United States)

    Josefson, Alf B

    2016-01-01

    The relative importance of environment and dispersal related processes for community assembly has attracted great interest over recent decades, but few empirical studies from the marine/estuarine realm have examined the possible effects of these two types of factors in the same system. Importance of these processes was investigated in a hypothetical metacommunity of benthic invertebrates in 16 micro-tidal estuaries connected to the same open sea area. The estuaries differed in size and connectivity to the open sea and represented a salinity gradient across the estuaries. The Elements of Metacommunity Structure (EMS) approach on estuary scale was complemented with a mechanistic variance partitioning approach on sample scale to disentangle effects of factors affecting assembly of three trait groups of species with different dispersivity. A quasi-Clementsian pattern was observed for all three traits, a likely response to some latent gradient. The primary axis in the pattern was most strongly related to gradients in estuary salinity and estuary entrance width and correlation with richness indicated nestedness only in the matrix of the most dispersive trait group. In the variance partitioning approach measures of turnover and nestedness between paired samples each from different estuaries were related to environmental distance in different gradients. Distance between estuaries was unimportant suggesting importance of factors characterizing the estuaries. While the high dispersive species mainly were sorted in the salinity gradient, apparently according to their tolerance ranges towards salinity, the two less dispersive traits were additionally affected by estuary entrance width and possibly also area. The results exemplify a mechanism of community assembly in the marine realm where the niche factor salinity in conjunction with differential dispersal structure invertebrates in a metacommunity of connected estuaries, and support the idea that dispersive species are more

  4. 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.

  5. 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.

  6. Global occurrence of pyrethroid insecticides in sediment and the associated toxicological effects on benthic invertebrates: An overview.

    Science.gov (United States)

    Li, Huizhen; Cheng, Fei; Wei, Yanli; Lydy, Michael J; You, Jing

    2017-02-15

    Pyrethroids are the third most applied group of insecticides worldwide and are extensively used in agricultural and non-agricultural applications. Pyrethroids exhibit low toxicity to mammals, but have extremely high toxicity to fish and non-target invertebrates. Their high hydrophobicity, along with pseudo-persistence due to continuous input, indicates that pyrethroids will accumulate in sediment, pose long-term exposure concerns to benthic invertebrates and ultimately cause significant risk to benthic communities and aquatic ecosystems. The current review synthesizes the reported sediment concentrations of pyrethroids and associated toxicity to benthic invertebrates on a global scale. Geographically, the most studied area was North America, followed by Asia, Europe, Australia and Africa. Pyrethroids were frequently detected in both agricultural and urban sediments, and bifenthrin and cypermethrin were identified as the main contributors to toxicity in benthic invertebrates. Simulated hazard quotients (HQ) for sediment-associated pyrethroids to benthic organisms ranged from 10.5±31.1 (bifenthrin) to 41.7±204 (cypermethrin), suggesting significant risk. The current study has provided evidence that pyrethroids are not only commonly detected in the aquatic environment, but also can cause toxic effects to benthic invertebrates, and calls for better development of accurate sediment quality criteria and effective ecological risk assessment methods for this emerging class of insecticides. Copyright © 2016 Elsevier B.V. All rights reserved.

  7. Temperature tracking by North Sea benthic invertebrates in response to climate change.

    Science.gov (United States)

    Hiddink, Jan G; Burrows, Michael T; García Molinos, Jorge

    2015-01-01

    Climate change is a major threat to biodiversity and distributions shifts are one of the most significant threats to global warming, but the extent to which these shifts keep pace with a changing climate is yet uncertain. Understanding the factors governing range shifts is crucial for conservation management to anticipate patterns of biodiversity distribution under future anthropogenic climate change. Soft-sediment invertebrates are a key faunal group because of their role in marine biogeochemistry and as a food source for commercial fish species. However, little information exists on their response to climate change. Here, we evaluate changes in the distribution of 65 North Sea benthic invertebrate species between 1986 and 2000 by examining their geographic, bathymetric and thermal niche shifts and test whether species are tracking their thermal niche as defined by minimum, mean or maximum sea bottom (SBT) and surface (SST) temperatures. Temperatures increased in the whole North Sea with many benthic invertebrates showing north-westerly range shifts (leading/trailing edges as well as distribution centroids) and deepening. Nevertheless, distribution shifts for most species (3.8-7.3 km yr(-1) interquantile range) lagged behind shifts in both SBT and SST (mean 8.1 km yr(-1)), resulting in many species experiencing increasing temperatures. The velocity of climate change (VoCC) of mean SST accurately predicted both the direction and magnitude of distribution centroid shifts, while maximum SST did the same for contraction of the trailing edge. The VoCC of SBT was not a good predictor of range shifts. No good predictor of expansions of the leading edge was found. Our results show that invertebrates need to shift at different rates and directions to track the climate velocities of different temperature measures, and are therefore lagging behind most temperature measures. If these species cannot withstand a change in thermal habitat, this could ultimately lead to a drop in

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

    African Journals Online (AJOL)

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

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

    International Nuclear Information System (INIS)

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

    1993-01-01

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

  10. Vessel biofouling as an inadvertent vector of benthic invertebrates occurring in Brazil.

    Science.gov (United States)

    Farrapeira, Cristiane Maria Rocha; Tenório, Deusinete de Oliveira; Amaral, Fernanda Duarte do

    2011-04-01

    This article reviews the literature involving benthic invertebrates that are cited in association with hull fouling, reporting the species that occur on the Brazilian coast and evaluating the importance of this vector for the introduction of nonindigenous and cryptogenic invertebrates in Brazil. It discusses some of the strategies that were used by the species that allowed for their overseas transport and made it easier to cross natural barriers that otherwise would have been obstacles to their dispersion. The compiled data list 343 species (65% nonindigenous and 35% cryptogenic), mainly from the northwestern Atlantic Ocean. The traveling fauna, composed mostly of cosmopolitan species (70.3%), is primarily euryhaline and marine stenohaline, with sessile and sedentary habits. After delineating the shipborne species' ecological profiles and traveling strategies and evaluating their overlapping vectors, we concluded that hull vessels were the main vector of introduction to the Brazilian coast for 89.8% of the compiled species. Copyright © 2010 Elsevier Ltd. All rights reserved.

  11. Effects of offshore oil drilling on benthic invertebrate communities on the Grand Banks (North Atlantic)

    Energy Technology Data Exchange (ETDEWEB)

    DeBlois, E. [Jacques Whitford Ltd., St. John' s, NL (Canada); Wight, F. [Husky Oil Operations Ltd., St. John' s, NL (Canada); Taylor, D. [DG Taylor Inc., Conception Bay South, NL (Canada); Paine, M. [Paine, Ledge and Associates, North Vancouver, BC (Canada)

    2007-07-01

    Drilling occurs at three different drill centres of the White Rose (WR) oil platform that lies 350 km offshore from St. John's Newfoundland. An extensive environmental effects monitoring (EEM) program conducted by Husky Energy is underway at the WR site. The sediment component of the program involves the measurement of physical and chemical characteristics, an assessment of toxicity in laboratory tests, and an assessment of in situ benthic invertebrate communities. Baseline sampling occurred in 2000, followed by post-drilling sampling in 2004 to 2006. The sediment is 95 per cent sand, with polychaetes and bivalves dominating the invertebrate communities. A comparative evaluation was performed for regressions between community variables and distances from drill centres before and after drilling. Concentration-response relationships between community variables and concentrations of major constituents in drilling muds (C10-C21 HCs) were also compared among years. It was shown that the biological effects on invertebrate communities were highly restricted to reductions in the amount of Paraonidae and Amphipoda near drill centres and at higher C10-C21 HC concentrations. The study revealed that the two most abundant invertebrate communities were not influenced by drilling in terms of standing crop, richness, diversity and evenness.

  12. 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

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

    International Nuclear Information System (INIS)

    Lagauzere, S.

    2008-06-01

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

  14. Antifouling activity in some benthic Antarctic invertebrates by "in situ" experiments at Deception Island, Antarctica.

    Science.gov (United States)

    Angulo-Preckler, Carlos; Cid, Cristina; Oliva, Francesc; Avila, Conxita

    2015-04-01

    Competition for space is a remarkable ecological force, comparable to predation, producing a strong selective pressure on benthic invertebrates. Some invertebrates, thus, possess antimicrobial compounds to reduce surface bacterial growth. Antimicrobial inhibition is the first step in avoiding being overgrown by other organisms, which may have a negative impact in feeding, respiration, reproduction … The in situ inhibition of bacterial biofilm was used here as an indicator of antifouling activity by testing hydrophilic extracts of twelve Antarctic invertebrates. Using two different approaches (genetics and confocal techniques) different levels of activity were found in the tested organisms. In fact, differences within body parts of the studied organisms were determined, in agreement with the Optimal Defense Theory. Eight out of 15 extracts tested had negative effects on fouling after 28 days submerged in Antarctic waters. Thus, although chemical defenses may be quite species-specific in their ecological roles, these results suggest that different chemical strategies exist to deal with space competition. Copyright © 2015 Elsevier Ltd. All rights reserved.

  15. Impacts of Zayandehroud Dam on the Macro-benthic Invertebrate and Water Quality of Zayandehroud River using BMWP and ASPT Biological Indices

    Directory of Open Access Journals (Sweden)

    H. Ebrahimi Dastgerdi

    2017-09-01

    Full Text Available Dams provide benefits for human societies, but now they are considered as one of the most important factors influencing habitat degradation and changing the hydrological water flow. In order to study the ecological effects of Zayandehroud Dam on the benthic communities and water quality of Zayandehroud river, six sampling stations were selected on the river substrate using biological indicators such as BMWP (Biological Monitoring Working Party and ASPT(Average Score Per Taxa. Then, a quantitative survey of the macro- benthic invertebrates fauna was conducted with 3 replications at each station, from July to June 2014 with a 45- day interval period. The identified macro-benthic invertebrates belonged to 31 families, 16 orders and 7 classes. The results of BMWP index showed significant differences among sampling stations (p<0.001, and significant difference between seasons in all stations except Overgan station (p<0.05. ASPT index also revealed significant differences among the stations (p<0.01. In addition, the results of Shannon diversity index indicated that Zayanderoud Dam construction, has changed diversity and composition of downstream benthic communities due to alterations in the depth and speed of the water flow, as well as substrate structure.

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

    DEFF Research Database (Denmark)

    Josefson, Alf B.; Göke, Cordula

    Identification of sources of beta diversity, the change of diversity, is important to understand regulation of overall diversity. Additive partitioning of diversity (species richness and expH) compared to random, was performed on a quantitative benthic macro-invertebrate collection of > 400 speci...

  17. 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.

  18. 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

  19. Data for: A field-based model of the relationship between extirpation of salt-intolerant benthic invertebrates and background conductivity

    Data.gov (United States)

    U.S. Environmental Protection Agency — The data is provided in 2 zip files that share site identifiers. One data set contains biological (genus benthic invertebrate) data (Data Biological.zip) and the...

  20. 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.

  1. A Database of Historical Benthic Invertebrate Biodiversity Spanning 182 Years in Narragansett Bay (Rhode Island and Massachusetts)_Data_ v1

    Data.gov (United States)

    U.S. Environmental Protection Agency — To examine biodiversity trends over time, a master list was compiled of all benthic invertebrate species collected from the Narragansett Bay beginning with Totten’s...

  2. 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

  3. WATER QUALITY ANALYSIS OF LOTIC ECOSYSTEMS OF NERA AND CARAS RIVERS CATCHMENTS USING BENTHIC INVERTEBRATES AS BIOINDICATORS

    Directory of Open Access Journals (Sweden)

    CLAUDIA PETRUCEAN

    2009-01-01

    Full Text Available The study of the two watersheds involved the collection of twenty-four benthic samples from the main tributaries of Nera and Caras rivers, but also from the Nera river. The samples were collected in august 2009 with a benthic net, which had the mesh size of 250 μm, by disturbing the substrate upstream for three minutes, being thus qualitative samples. The next stage, working in the laboratory, consisted in separating the invertebrates from the substrate, sorting them to taxonomic categories and counting them. The data was statistically analized and interpreted. It led to the conclusion that the water quality in the two watersheds is good. In most of the sampling points the major groups of benthic macroinvertebrates were found, some of the sampling points were dominated by the EPT groups (Ephemeroptera, Plecoptera, Trichoptera which is known as a clean freshwater group, sensitive to pollution and human impact.

  4. Trophic Ecology of Benthic Marine Invertebrates with Bi-Phasic Life Cycles: What Are We Still Missing?

    Science.gov (United States)

    Calado, Ricardo; Leal, Miguel Costa

    2015-01-01

    The study of trophic ecology of benthic marine invertebrates with bi-phasic life cycles is critical to understand the mechanisms shaping population dynamics. Moreover, global climate change is impacting the marine environment at an unprecedented level, which promotes trophic mismatches that affect the phenology of these species and, ultimately, act as drivers of ecological and evolutionary change. Assessing the trophic ecology of marine invertebrates is critical to understanding maternal investment, larval survival to metamorphosis, post-metamorphic performance, resource partitioning and trophic cascades. Tools already available to assess the trophic ecology of marine invertebrates, including visual observation, gut content analysis, food concentration, trophic markers, stable isotopes and molecular genetics, are reviewed and their main advantages and disadvantages for qualitative and quantitative approaches are discussed. The challenges to perform the partitioning of ingestion, digestion and assimilation are discussed together with different approaches to address each of these processes for short- and long-term fingerprinting. Future directions for research on the trophic ecology of benthic marine invertebrates with bi-phasic life cycles are discussed with emphasis on five guidelines that will allow for systematic study and comparative meta-analysis to address important unresolved questions. © 2015 Elsevier Ltd. All rights reserved.

  5. Energetic constraints, size gradients, and size limits in benthic marine invertebrates.

    Science.gov (United States)

    Sebens, Kenneth P

    2002-08-01

    Populations of marine benthic organisms occupy habitats with a range of physical and biological characteristics. In the intertidal zone, energetic costs increase with temperature and aerial exposure, and prey intake increases with immersion time, generating size gradients with small individuals often found at upper limits of distribution. Wave action can have similar effects, limiting feeding time or success, although certain species benefit from wave dislodgment of their prey; this also results in gradients of size and morphology. The difference between energy intake and metabolic (and/or behavioral) costs can be used to determine an energetic optimal size for individuals in such populations. Comparisons of the energetic optimal size to the maximum predicted size based on mechanical constraints, and the ensuing mortality schedule, provides a mechanism to study and explain organism size gradients in intertidal and subtidal habitats. For species where the energetic optimal size is well below the maximum size that could persist under a certain set of wave/flow conditions, it is probable that energetic constraints dominate. When the opposite is true, populations of small individuals can dominate habitats with strong dislodgment or damage probability. When the maximum size of individuals is far below either energetic optima or mechanical limits, other sources of mortality (e.g., predation) may favor energy allocation to early reproduction rather than to continued growth. Predictions based on optimal size models have been tested for a variety of intertidal and subtidal invertebrates including sea anemones, corals, and octocorals. This paper provides a review of the optimal size concept, and employs a combination of the optimal energetic size model and life history modeling approach to explore energy allocation to growth or reproduction as the optimal size is approached.

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

    Science.gov (United States)

    Sohtome, Tadahiro; Wada, Toshihiro; Mizuno, Takuji; Nemoto, Yoshiharu; Igarashi, Satoshi; Nishimune, Atsushi; Aono, Tatsuo; Ito, Yukari; Kanda, Jota; Ishimaru, Takashi

    2014-12-01

    Radioactive cesium ((134)Cs and (137)Cs) 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 (137)Cs concentrations within detected data were often found in areas near or south of the FDNPP, which is consistent with the reported spatial distribution of (137)Cs concentrations in highly contaminated seawater and sediments after the FDNPP accident. Overall (137)Cs 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 (137)Cs 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. Copyright © 2014 Elsevier Ltd. All rights reserved.

  7. Ecosystem stress response : understanding effects on the benthic invertebrate community of Alberta oil-sands wetlands

    International Nuclear Information System (INIS)

    Wytrykush, C.M.; Ciborowski, J.J.H.

    2003-01-01

    The environmental stress response of invertebrates was examined using wetlands in the Alberta oil-sands region as a model. Wetlands in this region occur naturally or they have been affected by oil-sands mining process materials such as mine-tailings, or saline process water. These materials can be toxic to aquatic organisms due to their high concentrations of sulphate ions, ammonia, polycyclic aromatic hydrocarbons (PAHs) and naphthenic acids. Wetlands are classified as either young or mature, and as having low or high sediment organic content. This study examined food web dynamics and structure in wetlands using stable isotopes to determine the effects of stress on ecological communities. Primary and secondary production in the wetlands was measured along with invertebrate diversity in order to determine a relationship. The maximum trophic position was determined using stable carbon and nitrogen isotopes to indicate food chain length which is influenced by energetic constraints, ecosystem size and stressors. The study quantifies the dynamics of vital links between the responses to environmental pressures in aquatic systems and the effects on terrestrial ecosystems

  8. Occurrence and risk assessment of trace metals and metalloids in sediments and benthic invertebrates from Dianshan Lake, China.

    Science.gov (United States)

    Wu, Yan; Zhou, Yihui; Qiu, Yanling; Chen, Da; Zhu, Zhiliang; Zhao, Jianfu; Bergman, Ǻke

    2017-06-01

    The present study measured concentrations of Cr, Ni, Cu, Zn, As, Cd, Sb, and Pb in surface sediments and two benthic invertebrate species (Anodonta woodiana and Bellamya aeruginosa) collected from Dianshan Lake, located in the Yangtze River Delta. The Dianshan Lake acts as one of the most important drinking water sources to Shanghai, the biggest city in China. Concentrations of trace metals and metalloids ranged from 0.04 mg/kg for Cd to 288.0 mg/kg for Zn. Substantial bioaccumulation in invertebrates was observed for Zn and Cu based on the biota-sediment accumulation factor (BSAF) measurements. The results revealed that concentrations of metals and metalloids in sediments from Dianshan Lake were at the lower end of the range of levels found in other regions of China. The assessment of three significantly inter-related evaluation indices, including the geo-accumulation Index (I geo ), potential ecological risk factor (Er i ), and mean probable effect concentration quotients (Q m-PEC ), suggested that sediment-associated trace elements exhibited no considerable ecological risks in the studied watershed. However, the target hazard quotient and hazard index analysis suggested that selected elements (particularly As) accumulation in edible tissues of benthic invertebrates could pose potential health risks to local populations, especially fishermen. Given that wild aquatic organisms (e.g., fish and bivalves) constitute the diet of local populations as popular food/protein choices, further investigations are needed to better elucidate human health risks from metal and metalloid exposure via edible freshwater organisms.

  9. Diagnosis of potential stressors adversely affecting benthic invertebrate communities in Greenwich Bay, Rhode Island, USA

    Science.gov (United States)

    Greenwich Bay is an urbanized embayment of Narragansett Bay potentially impacted by multiple stressors. The present study identified the important stressors affecting Greenwich Bay benthic fauna. First, existing data and information were used to confirm that the waterbody was imp...

  10. PCB contamination and effects on benthic invertebrate communities at the Irving Whale salvage site

    National Research Council Canada - National Science Library

    Ernst, W

    2000-01-01

    ... patterns of polychlorinated biphenyl (PCB) contamination. In addition, snow crab tissue sampling, toxicity testing of sediments as well as analysis of the integrity of benthic biological communities was conducted around the Irving Whale footprint...

  11. Determination of food sources for benthic invertebrates in a salt marsh (Aiguillon Bay, France) by carbon and nitrogen stable isotopes: importance of locally produced sources

    NARCIS (Netherlands)

    Riera, P.; Stal, L.J.; Nieuwenhuize, J.; Richard, P.; Blanchard, G.F.; Gentil, F.

    1999-01-01

    delta(13)C and delta(15)N were measured in benthic invertebrates and food sources collected in the salt marsh of the Aiguillon Bay, France. The results showed that, although Spartina anglica was dominant, this marine phanerogame did not contribute significantly to the carbon and nitrogen

  12. Benthic invertebrate exposure and chronic toxicity risk analysis for cyclic volatile methylsiloxanes: Comparison of hazard quotient and probabilistic risk assessment approaches.

    Science.gov (United States)

    Woodburn, Kent B; Seston, Rita M; Kim, Jaeshin; Powell, David E

    2018-02-01

    This study utilized probabilistic risk assessment techniques to compare field sediment concentrations of the cyclic volatile methylsiloxane (cVMS) materials octamethylcyclotetrasiloxane (D4, CAS # 556-67-2), decamethylcyclopentasiloxane (D5, CAS # 541-02-6), and dodecamethylcyclohexasiloxane (D6, CAS # 540-97-6) to effect levels for these compounds determined in laboratory chronic toxicity tests with benthic organisms. The concentration data for D4/D5/D6 in sediment were individually sorted and the 95th centile concentrations determined in sediment on an organic carbon (OC) fugacity basis. These concentrations were then compared to interpolated 5th centile benthic sediment no-observed effect concentration (NOEC) fugacity levels, calculated from a distribution of chronic D4/D5/D6 toxicologic assays per OECD guidelines using a variety of standard benthic species. The benthic invertebrate fugacity biota NOEC values were then compared to field-measured invertebrate biota fugacity levels to see if risk assessment evaluations were similar on a field sediment and field biota basis. No overlap was noted for D4 and D5 95th centile sediment and biota fugacity levels and their respective 5th centile benthic organism NOEC values. For D6, there was a small level of overlap at the exposure 95th centile sediment fugacity and the 5th centile benthic organism NOEC fugacity value; the sediment fugacities indicate that a negligible risk (1%) exists for benthic species exposed to D6. In contrast, there was no indication of risk when the field invertebrate exposure 95th centile biota fugacity and the 5th centile benthic organism NOEC fugacity values were compared. Copyright © 2017 The Authors. Published by Elsevier Ltd.. All rights reserved.

  13. 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/.

  14. Laboratory toxicity and benthic invertebrate field colonization of Upper Columbia River sediments: finding adverse effects using multiple lines of evidence.

    Science.gov (United States)

    Fairchild, J F; Kemble, N E; Allert, A L; Brumbaugh, W G; Ingersoll, C G; Dowling, B; Gruenenfelder, C; Roland, J L

    2012-07-01

    From 1930 to 1995, the Upper Columbia River (UCR) of northeast Washington State received approximately 12 million metric tons of smelter slag and associated effluents from a large smelter facility located in Trail, British Columbia, approximately 10 km north of the United States-Canadian border. Studies conducted during the past two decades have demonstrated the presence of toxic concentrations of heavy metals in slag-based sandy sediments, including cadmium, copper, zinc, and lead in the UCR area as well as the downstream reservoir portion of Lake Roosevelt. We conducted standardized whole-sediment toxicity tests with the amphipod Hyalella azteca (28-day) and the midge Chironomus dilutus (10-day) on 11 samples, including both UCR and study-specific reference sediments. Metal concentrations in sediments were modeled for potential toxicity using three approaches: (1) probable effects quotients (PEQs) based on total recoverable metals (TRMs) and simultaneously extracted metals (SEMs); (2) SEMs corrected for acid-volatile sulfides (AVS; i.e., ∑SEM - AVS); and (3) ∑SEM - AVS normalized to the fractional organic carbon (f(oc)) (i.e., ∑SEM - AVS/f(oc)). The most highly metal-contaminated sample (∑PEQ(TRM) = 132; ∑PEQ(SEM) = 54; ∑SEM - AVS = 323; and ∑SEM - AVS/(foc) = 64,600 umol/g) from the UCR was dominated by weathered slag sediment particles and resulted in 80% mortality and 94% decrease in biomass of amphipods; in addition, this sample significantly decreased growth of midge by 10%. The traditional ∑AVS - SEM, uncorrected for organic carbon, was the most accurate approach for estimating the effects of metals in the UCR. Treatment of the toxic slag sediment with 20% Resinex SIR-300 metal-chelating resin significantly decreased the toxicity of the sample. Samples ∑SEM - AVS > 244 was not toxic to amphipods or midge in laboratory testing, indicating that this value may be an approximate threshold for effects in the UCR. In situ benthic invertebrate

  15. Spatial and temporal patterns of benthic invertebrates in the Tagus estuary, Portugal: comparison between subtidal and an intertidal mudflat

    Directory of Open Access Journals (Sweden)

    Susana França

    2009-06-01

    Full Text Available Intertidal mudflats are a dominant feature in many estuarine systems and may be a significant component of the feeding grounds available for many fish and bird species. Therefore, it is crucial to determine the importance and role that this particular habitat plays for the different estuarine communities. Spatial and temporal dynamics of macrobenthic communities in an intertidal mudflat of the Tagus estuary were assessed in order to determine the role of this habitat in the whole estuarine functioning. Benthic macroinvertebrate communities were sampled monthly in two intertidal areas (upper and lower and in the adjoining subtidal area for one year. Macroinvertebrate density and biomass in the intertidal mudflat were higher than in the subtidal area, but no clear trends were found between the lower and upper intertidal area. Spatial patterns in the community were more pronounced than seasonal patterns. This benthic community was characterised by high densities of Pygospio elegans, Scrobicularia plana, Cyathura carinata, Hydrobia ulvae and Nereis diversicolor. Abundance and biomass values in this intertidal mudflat were considered low in comparison with other estuarine habitats, namely seagrass beds. Nevertheless, this habitat plays an important role for the main species present in the community, acting as a key area for recruitment, with high concentrations for many invertebrate species.

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

    KAUST Repository

    Chandramouli, Kondethimmanahalli

    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.

  17. Subtidal Benthic Invertebrates Shifting Northward Along the U.S. Atlantic Coast

    Science.gov (United States)

    Numerous marine and terrestrial species have shifted their ranges poleward in response to warming from global climate change. However, few studies have examined range shifts of subtidal benthic communities in estuarine and nearshore waters. This study examined 20 years (1990–2010...

  18. Gray whale distribution relative to benthic invertebrate biomass and abundance: Northeastern Chukchi Sea 2009-2012

    Science.gov (United States)

    Brower, Amelia A.; Ferguson, Megan C.; Schonberg, Susan V.; Jewett, Stephen C.; Clarke, Janet T.

    2017-10-01

    The shallow continental shelf waters of the Bering and Chukchi seas are the northernmost foraging grounds of North Pacific gray whales (Eschrichtius robustus). Benthic amphipods are considered the primary prey of gray whales in these waters, although no comprehensive quantitative analysis has been performed to support this assumption. Gray whale relative abundance, distribution, and behavior in the northeastern Chukchi Sea (69°-72°N, 155-169°W) were documented during aerial surveys in June-October 2009-2012. Concurrently, vessel-based benthic infaunal sampling was conducted in the area in July-August 2009-10, September 2011, and August 2012. Gray whales were seen in the study area each month that surveys were conducted, with the majority of whales feeding. Statistical analyses confirm that the highest densities of feeding gray whales were associated with high benthic amphipod abundance, primarily within 70 km of shore from Point Barrow to Icy Cape, in water whales were not seen in 40-km×40-km cells containing benthic sampling stations with 85 m-2 or fewer amphipods. Continuing broad-scale aerial surveys in the Chukchi Sea and prey sampling near feeding gray whales will be an important means to monitor and document ongoing and predicted ecosystem changes.

  19. Marine snow increases the adverse effects of oil on benthic invertebrates

    NARCIS (Netherlands)

    Eenennaam, Van Justine S.; Rahsepar, Shokouh; Radović, Jagoš R.; Oldenburg, Thomas B.P.; Wonink, Jessica; Langenhoff, Alette A.M.; Murk, Albertinka J.; Foekema, Edwin M.

    2018-01-01

    After the Deepwater Horizon oil spill, a MOSSFA (Marine Oil Snow Sedimentation and Flocculent Accumulation) event took place, transporting an estimated 14% of total released oil to the sediment, and smothering parts of the benthic ecosystem. This microcosm study describes the effects of oiled

  20. Identification of threshold body burdens of metals for the protection of the aquatic ecological status using two benthic invertebrates

    International Nuclear Information System (INIS)

    Bervoets, Lieven; De Jonge, Maarten; Blust, Ronny

    2016-01-01

    In this study accumulated concentrations of As, Cd, Cr, Cu, Ni, Pb and Zn in two benthic invertebrate taxa, Chironomus sp. and Tubificidae are related to ecological responses expressed as changes in macro invertebrate communities. In addition critical body burdens were estimated above which ecological quality was always lower than a certain threshold. Data from existing studies on bioaccumulation of the metals in both taxa were combined with different biological water quality indices. For all metal-endpoint combinations threshold values could be calculated above which ecological quality was always low. Safe threshold body burdens could be estimated for both species for all metals although the data set was more extended for Chrionomus sp. with estimated threshold values being 65, 3.2, 10, 57, 6.5, 73 and 490 μg/g dw for As, Cd, Cr, Cu, Ni, Pb and Zn. This study demonstrated that metal accumulation in resistant species such as chironomids and tubificid worms have the potential to be used as predictors of ecological effects in aquatic ecosystems. However, the estimated threshold values have to be validated and supported by more lines of evidence before they can be used by regulators. - Highlights: • Chironomid larvae and Tubificid worms can be used to relate accumulated metals to ecological endpoints. • Ecological water quality, calculated with biotic indices, is always low at high accumulated metal concentrations. • Critical body burdens in chironomids and tubificds could be estimated for As, Cd, Cr, Cu, Ni, Pb and Zn. - Maximal body burdens of metals in two invertebrate species could be estimated above which ecological quality was always low.

  1. Influence of acidification and aluminium on the density and biomass of lotic benthic invertebrates

    Energy Technology Data Exchange (ETDEWEB)

    Allard, M.; Moreau, G.

    1986-10-01

    Experiments were carried out in plasticized wooden channels fed by a small creek in the Reserve des Laurentides, 80 km north of Quebec city. Channels were naturally colonized by invertebrates for 65 d before treatment. Treated channels were acidified in August with dilute H/sub 2/SO/sub 4/ only, or with acid plus a solution of Al sulfate (final concentration of 0.19 mg L/sup -1/). The control channel received creek water only (pH 6.3 to 6.9). The addition of Al had no effect on invertebrate density and biomass. After 73 d of acidification, invertebrate densities were only one third the number found in the control channel. Invertebrate biomass was not different within channels, although biomass was generally higher in the two acidified channels. Difference in densities between acidified and non-acidified channels was attributed to lack of colonization and not to an increase in drift. Microtendipes, a large and resistant larva of Chironomidae constituted a large fraction of the biomass, largely outweighing numerous very small larvae. Effects on the density were attributed to the direct effect of low pH and not to indirect action through food limitations. 22 refs.

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

    NARCIS (Netherlands)

    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,

  3. 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

  4. Radiotracers in the study of marine food chains. The use of compartmental analysis and analog modelling in measuring utilization rates of particulate organic matter by benthic invertebrates

    International Nuclear Information System (INIS)

    Gremare, A.; Amouroux, J.M.; Charles, F.

    1991-01-01

    The present study assesses the problem of recycling when using radiotracers to quantify ingestion and assimilation rates of particulate organic matter by benthic invertebrates. The rapid production of dissolved organic matter and its subsequent utilization by benthic invertebrates constitutes a major bias in this kind of study. However recycling processes may also concern POM through the production and reingestion of faeces. The present paper shows that compartmental analysis of the diffusion kinetics of the radiotracer between the different compartments of the system studied and the analog modelling of the exchanges of radioactivity between compartments may be used in order to determine ingestion and assimilation rates. This method is illustrated by the study of a system composed of the bacteria Lactobacillus sp. and the filter-feeding bivalve Venerupis decussata. The advantages and drawbacks of this approach relative to other existing methods are briefly discussed. (Author)

  5. 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

    2013-01-01

    on dissolved oxygen concentrations (DO) have not yet received much attention. We compared the macroinvertebrate composition between reference conditions and a situation after several years of discharge reduction in the Spree River (Brandenburg, Germany). Community composition shifted from rheophilic species...... 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...

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

    Science.gov (United States)

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

    2003-01-01

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

  7. 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)

    Sohtome, Tadahiro; Wada, Toshihiro; Mizuno, Takuji; Nemoto, Yoshiharu; Igarashi, Satoshi; Nishimune, Atsushi; Aono, Tatsuo; Ito, Yukari; Kanda, Jota; Ishimaru, Takashi

    2014-01-01

    Radioactive cesium ( 134 Cs and 137 Cs) 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 137 Cs concentrations within detected data were often found in areas near or south of the FDNPP, which is consistent with the reported spatial distribution of 137 Cs concentrations in highly contaminated seawater and sediments after the FDNPP accident. Overall 137 Cs 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 137 Cs 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 137 Cs concentration was found in Bivalvia and Gastropoda. • Slow depuration was observed in Polychaeta and Malacostraca. • Sediments are expected to be the major

  8. Native freshwater species get out of the way: Prussian carp (Carassius gibelio) impacts both fish and benthic invertebrate communities in North America.

    Science.gov (United States)

    Ruppert, Jonathan L W; Docherty, Cassandra; Neufeld, Kenton; Hamilton, Kyle; MacPherson, Laura; Poesch, Mark S

    2017-10-01

    Prussian carp ( Carassius gibelio ) are one of the most noxious non-native species in Eurasia. Recently, Prussian carp, a non-native freshwater fish species, were genetically confirmed in Alberta, Canada and have been rapidly expanding their range in North America since establishment. Given their rapid range expansion, there is an increasing need to determine how Prussian carp may impact native species. We assessed the severity of the Prussian carp invasion by (i) determining their impact on fish communities, (ii) assessing their impact on benthic invertebrate communities, (iii) evaluating if Prussian carp alter abiotic conditions, and (iv) identifying where we find higher abundances of Prussian carp. When Prussian carp were established, we found significant changes to the fish community. Correspondingly, the degree of impact to benthic invertebrate communities was related to the stage of invasion (none, early or recent), where changes in fish communities were significantly concordant with changes in benthic invertebrate communities. Finally, we found that higher abundances of Prussian carp were significantly associated with lower abundances of a majority of native fish species. Altogether, using three lines of evidence, we determine that Prussian carp can have wide-ranging impacts on freshwater ecosystems in North America, pressing the need for management intervention.

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

    Science.gov (United States)

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

    2013-01-01

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

  10. Behavioural responses of indigenous benthic invertebrates (Echinogammarus meridionalis, Hydropsyche pellucidula and Choroterpes picteti) to a pulse of Acid Mine Drainage: A laboratorial study

    International Nuclear Information System (INIS)

    Macedo-Sousa, Joaquim A.; Gerhardt, Almut; Brett, Christopher M.A.; Nogueira, Antonio J.A.; Soares, Amadeu M.V.M.

    2008-01-01

    The drainage of abandoned mines leads to several ecological problems, particularly the acidification of surface freshwater systems and heavy metal contamination. In order to study the possibility of using the behavioural early warning responses of Portuguese indigenous benthic invertebrates to detect an acute short-term pulse of Acid Mine Drainage (AMD), experiments with the Multispecies Freshwater Biomonitor MFB TM were performed and locomotion and ventilation were measured as endpoints. AMD was collected from the 'Sao Domingos' mine (Southeast Portugal) and the following species were selected: Echinogammarus meridionalis (Pinkster, 1973), Hydropsyche pellucidula (Curtis, 1834) and Choroterpes picteti (Eaton, 1870). For simulating the pulsed exposure, AMD was added to river water where invertebrates were collected and pH was lowered until reaching 3.5. The effects of H + and heavy metals were discriminated using HCl positive controls. In addition to behaviour, mortality was registered. E. meridionalis was the most sensitive species in terms of mortality and behavioural endpoints, followed by C. picteti and H. pellucidula. E. meridionalis early warning responses consisted of increased locomotion with subsequent increase in ventilation, whereas for C. picteti only an increase in locomotion was observed. H. pellucidula showed no early warning responses. This work demonstrates the suitableness of using benthic invertebrates' behavioural early warning responses for detecting spikes of pollutants like AMD. - Behavioural responses of aquatic invertebrates may be used to detect spikes of Acid Mine Drainage

  11. Abyssal near-bottom dispersal stages of benthic invertebrates in the Clarion-Clipperton polymetallic nodule province

    Science.gov (United States)

    Kersten, Oliver; Smith, Craig R.; Vetter, Eric W.

    2017-09-01

    Growing interest in polymetallic nodule mining has intensified the need to characterize the abundance, community structure and vertical flux of meroplankton in the Clarion-Clipperton Zone (CCZ) to facilitate the estimation of larval supply and potential connectivity of benthic populations. These ecological parameters are essential to predict recolonization processes following the expected large-scale, high intensity disturbances associated with nodule extraction. Here, we present the first description of the composition, abundance, temporal variability, and mesoscale distribution of dispersing stages of the benthos in two study areas in the eastern CCZ. Samples from free-vehicle plankton pumps showed little variation in meroplankton diversity and abundance over scales of 30-100 km for time scales of days to weeks. However, sediment-trap samples revealed high temporal variability in vertical flux over weeks to months. Larval abundances and fluxes measured in the abyssal CCZ are 1-2 orders of magnitude lower than observed at deep-sea ridge and hydrothermal-vent habitats. We found significantly higher downward larval fluxes at 11 m above the bottom (mab) than at 146 mab, indicating accumulation or retention of meroplankton within the Benthic Boundary Layer (BBL). The high abundance of meroplankton in the BBL emphasizes its importance to dispersing stages and suggests that the creation of large sediment plumes in the BBL during nodule mining could compromise the dispersal and recruitment abilities of the abyssal benthos, potentially slowing rates and altering patterns of benthic community recovery following mining disturbance.

  12. 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

  13. Radionuclide concentrations in benthic invertebrates from Amchitka and Kiska Islands in the Aleutian Chain, Alaska.

    Science.gov (United States)

    Burger, Joanna; Gochfeld, Michael; Jewett, Stephen C

    2007-05-01

    Concentrations of 13 radionuclides (137Cs, 129I, 60Co, 152Eu, 90Sr, 99Tc, 241Am, 238Pu, 239,249Pu, 234U, 235U, 236U, 238U) were examined in seven species of invertebrates from Amchitka and Kiska Islands, in the Aleutian Chain of Alaska, using gamma spectroscopy, inductively coupled plasma mass spectroscopy, and alpha spectroscopy. Amchitka Island was the site of three underground nuclear test (1965-1971), and we tested the null hypotheses that there were no differences in radionuclide concentrations between Amchitka and the reference site (Kiska) and there were no differences among species. The only radionuclides where composite samples were above the Minimum Detectable Activity (MDA) were 137Cs, 241Am, 239,249Pu, 234U, 235U, 236U, and 238U. Green sea urchin (Strongylocentrotus polyacanthus), giant chiton (Cryptochiton stelleri), plate limpets (Tectura scutum) and giant Pacific octopus (Enteroctopus dofleini) were only tested for 137Cs; octopus was the only species with detectable levels of 137Cs (0.262 +/- 0.029 Bq/kg, wet weight). Only rock jingle (Pododesmus macroschisma), blue mussel (Mytilus trossulus) and horse mussel (Modiolus modiolus) were analyzed for the actinides. There were no interspecific differences in 241Am and 239,240Pu, and almost no samples above the MDA for 238Pu and 236U. Horse mussels had significantly higher concentrations of 234U (0.844 +/- 0.804 Bq/kg) and 238U (0.730 +/- 0.646) than the other species (both isotopes are naturally occurring). There were no differences in actinide concentrations between Amchitka and Kiska. In general, radionuclides in invertebrates from Amchitka were similar to those from uncontaminated sites in the Northern Hemisphere, and below those from the contaminated Irish Sea. There is a clear research need for authors to report the concentrations of radionuclides by species, rather than simply as 'shellfish', for comparative purposes in determining geographical patterns, understanding possible effects, and for

  14. 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.

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

    KAUST Repository

    Steckbauer, Alexandra; Ramajo, Laura; Hendriks, Iris E.; Fernandez, Miriam; Lagos, Nelson A.; Prado, Luis; Duarte, Carlos M.

    2015-01-01

    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.

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

    Science.gov (United States)

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

    2014-12-01

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

  17. 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.

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

    KAUST Repository

    Jessen, Christian; Voolstra, Christian R.; Wild, Christian

    2014-01-01

    overfishing through predator/grazer exclusion and simulated eutrophication through fertilizer addition on settlement of reef associated invertebrates on light-exposed and -shaded tiles over 4 months. At the end of the study period invertebrates had almost

  19. Benthic infaunal community structuring in an acidified tropical estuarine system.

    Science.gov (United States)

    Hossain, M Belal; Marshall, David J

    2014-01-01

    Recent studies suggest that increasing ocean acidification (OA) should have strong direct and indirect influences on marine invertebrates. While most theory and application for OA is based on relatively physically-stable oceanic ecological systems, less is known about the effects of acidification on nearshore and estuarine systems. Here, we investigated the structuring of a benthic infaunal community in a tropical estuarine system, along a steep salinity and pH gradient, arising largely from acid-sulphate groundwater inflows (Sungai Brunei Estuary, Borneo, July 2011- June 2012). Preliminary data indicate that sediment pore-water salinity (range: 8.07 - 29.6 psu) declined towards the mainland in correspondence with the above-sediment estuarine water salinity (range: 3.58 - 31.2 psu), whereas the pore-water pH (range: 6.47- 7.72) was generally lower and less variable than the estuarine water pH (range: 5.78- 8.3), along the estuary. Of the thirty six species (taxa) recorded, the polychaetes Neanthes sp., Onuphis conchylega, Nereididae sp. and the amphipod Corophiidae sp., were numerically dominant. Calcified microcrustaceans (e.g., Cyclopoida sp. and Corophiidae sp.) were abundant at all stations and there was no clear distinction in distribution pattern along the estuarine between calcified and non-calcified groups. Species richness increased seawards, though abundance (density) showed no distinct directional trend. Diversity indices were generally positively correlated (Spearman's rank correlation) with salinity and pH (p 0.05). Three faunistic assemblages were distinguished: (1) nereid-cyclopoid-sabellid, (2) corophiid-capitellid and (3) onuphid- nereid-capitellid. These respectively associated with lower salinity/pH and a muddy bottom, low salinity/pH and a sandy bottom, and high salinity/pH and a sandy bottom. However, CCA suggested that species distribution and community structuring is more strongly influenced by sediment particle characteristics than by the

  20. The impact of the Cyanamid Canada Co. discharges to benthic invertebrates in the Welland River in Niagara falls, Canada.

    Science.gov (United States)

    Dickman, M; Rygiel, G

    1993-06-01

    : In 1986, the International Joint Commission (IJC) recommended that the Niagara River watershed should be declared an Area of Concern (AOC). This IJC recommendation was ratified by the 4 signatories of the Great Lakes Water Quality Agreement. In order to delist an AOC, it is necessary to locate any areas of impairment within the watershed and carry out remediation projects that permit uses that were previously impaired. To this end we attempted to determine whether or not the sediments at 7 study sites near the Cyanamid Canada (Chemical) Co. were contaminated at levels that would result in the impairment of the natural biota which inhabit the watershed.The Cyanamid Canada (Chemical) Co. discharges ammonia wastes, cyanide, arsenic and a variety of heavy metals into treatment systems which ultimately discharge to the Welland River, the major Canadian tributary to the Niagara River. This portion of the Welland River near the factory was designated a Provincially significant (Class one) wetlands by the Ontario Ministry of Natural Resources. In 1986, the mean discharge to a creek from Cyanamid Canada Co. was 27,342 m(3) per day (MOE, 1987). Similar discharge volumes occurred in 1989. In 1991, the total discharge was 25,000 m(3) per day (MOE, 1991).The majority of the benthic invertebrates collected from the study area were pollution tolerant taxa (e.g., sludge worms constituted 68% of all the organisms collected). The lowest chironomid densities were observed at stations 1, 2, and 4, which were the only stations situated close to Cyanamid's discharge pipes. The absence, of clams and mayflies which burrow to greater depths than do chironomids and sludge worms, probably reflects the inability of the deeper dwelling burrowers to tolerate the contaminants which we recorded at these 3 stations. The absence of all crustaceans from these same 3 stations (stations 1, 2 and 4) when coupled with their low biotic diversity and the elevated heavy metal concentrations in the

  1. Benthic community structures in the North Sea

    Science.gov (United States)

    Heip, C.; Craeymeersch, J. A.

    1995-03-01

    Coherent assemblages of marine benthic species have been recognized from the early twentieth century, and the classical papers of Petersen (1914, 1918) were based on studies of limited areas in the North Sea. In 1986, a synoptic survey of the North Sea north to 57°N was undertaken by a group of ten laboratories from seven North Sea countries. The results of this survey have recently been published (Heip et al., 1992a, b; Künitzer et al., 1992; Huys et al., 1992), and some of the results are summarized in this paper. The analysis of the macrofauna is based on slightly more than 700 taxa. In general, the North Sea macrofauna consists of northern species extending south to the northern margins of the Dogger Bank, and southern species extending north to the 100 m depth line. The central North Sea is an area of overlap of southern and northern species, especially around the 70 m depth contour. Consistent groupings of species are recognized that were summarized in seven faunal groupings. Macrofaunal body weight, density and diversity increase linearly towards the north. Macrofaunal biomass for the whole area averages 7 g adwt. m-2 and decreases from south to north. Distribution patterns and trends within the meiofauna were very different. Nematodes, which are the dominant taxon overall, are least abundant in the sandy sediments of the Southern Bight, then increase to a maximum around 53° 30' N and slowly decrease again towards the north. Copepod density and diversity are highest in the Southern Bight, due to the presence of many interstitial species. A large number of species new to science were recorded by the North Sea Benthos Survey and about 1500 species are expected to occur. Copepods show very distinct assemblages according to water depth and sediment type. The contrasting patterns in latitudinal gradients of body weight and number of species of macro- and meiofauna can be only partially explained. Latitude and sediment characteristics, such as grain size and

  2. The structure and host entry of an invertebrate parvovirus.

    Science.gov (United States)

    Meng, Geng; Zhang, Xinzheng; Plevka, Pavel; Yu, Qian; Tijssen, Peter; Rossmann, Michael G

    2013-12-01

    The 3.5-Å resolution X-ray crystal structure of mature cricket parvovirus (Acheta domesticus densovirus [AdDNV]) has been determined. Structural comparisons show that vertebrate and invertebrate parvoviruses have evolved independently, although there are common structural features among all parvovirus capsid proteins. It was shown that raising the temperature of the AdDNV particles caused a loss of their genomes. The structure of these emptied particles was determined by cryo-electron microscopy to 5.5-Å resolution, and the capsid structure was found to be the same as that for the full, mature virus except for the absence of the three ordered nucleotides observed in the crystal structure. The viral protein 1 (VP1) amino termini could be externalized without significant damage to the capsid. In vitro, this externalization of the VP1 amino termini is accompanied by the release of the viral genome.

  3. Alkane and polycyclic aromatic hydrocarbons in sediments and benthic invertebrates of the northern Chukchi Sea

    Science.gov (United States)

    Harvey, H. Rodger; Taylor, Karen A.

    2017-10-01

    The Hanna Shoal region represents an important northern gateway for transport and deposition in the Chukchi Sea. This study determined the concentration and distribution of organic contaminants (aliphatic hydrocarbon and polycyclic aromatic hydrocarbons, PAHs) in surface sediments from 34 sites across Hanna Shoal. Up to 31 total PAHs, including parent and alkyl homologues were detected with total concentrations ranging from a low of 168 ng g-1 the western flank of Hanna Shoal (station H34) to 1147 ng g-1 at station in Barrow Canyon (station BarC5). Alkyl PAHs were more abundant than parent structures and accounted for 53-64% of the summed concentrations suggesting overall at background levels (< 1600 ng g-1) in sediments. Alkane (C15-C33) hydrocarbons ranged from 4.3 μg g-1 on the southern flank of Hanna shoal to 31 μg g-1 at a northern station. Sediments were often dominated by short chain (C15-C22) alkanes with overall terrestrial aquatic ratios (TAR) for the region averaging 0.20. Based on the ratio of Fl/(Fl+ Py) and BaF/(Baf+BeP) verses (BA/BA+Ch) in sediments, PAHs are largely derived from petrogenic sources with minor amounts of mixed combustion sources. A diversity of PAHs were detected in the northern whelk Neptunea heros foot muscle with total concentrations ranging from 0.14 to 1.5 μg g-1 dry tissue wt. Larger (and presumably older) animals showed higher levels of PAH per unit muscle tissue, suggesting that animals may bioaccumulate PAHs over time, with low but increasing concentrations also present in internal and external eggs. Alkane hydrocarbons were also higher in whelks with distributions similar to that seen in sediments. The mussel Muscularus discors collected in Barrow Canyon showed constrained distributions and substantially lower concentrations of both PAHs and alkanes than the surrounding surface sediments.

  4. A closer look at the main actors of Neotropical floodplain food webs: functional classification and niche overlap of dominant benthic invertebrates in a floodplain lake of Paraná River

    OpenAIRE

    Saigo,Miguel; Marchese,Mercedes; Wantzen,Karl Matthias

    2016-01-01

    ABSTRACT Functional classification of animals is necessary to enhance the predictive power of food web models. However, while there is a large database for functional classification of benthic invertebrates (Functional Feeding Groups, FFG) in the temperate zone, the attribution of individual species of riverine invertebrates is still in its infancies in the Neotropical Region. Different authors hypothesized that diet breadth was larger in the Tropics, however detailed analysis are scarce. In ...

  5. In situ bioavailability of DDT and Hg in sediments of the Toce River (Lake Maggiore basin, Northern Italy): accumulation in benthic invertebrates and passive samplers.

    Science.gov (United States)

    Pisanello, Francesca; Marziali, Laura; Rosignoli, Federica; Poma, Giulia; Roscioli, Claudio; Pozzoni, Fiorenzo; Guzzella, Licia

    2016-06-01

    DDT and mercury (Hg) contamination in the Toce River (Northern Italy) was caused by a factory producing technical DDT and using a mercury-cell chlor-alkali plant. In this study, DDT and Hg contamination and bioavailability were assessed by using different approaches: (1) direct evaluation of sediment contamination, (2) assessment of bioaccumulation in native benthic invertebrates belonging to different taxonomic/functional groups, and (3) evaluation of the in situ bioavailability of DDT and Hg using passive samplers. Sampling sites were selected upstream and downstream the industrial plant along the river axis. Benthic invertebrates (Gammaridae, Heptageniidae, and Diptera) and sediments were collected in three seasons and analyzed for DDT and Hg content and the results were used to calculate the biota sediment accumulation factor (BSAF). Polyethylene passive samplers (PEs) for DDT and diffusive gradients in thin films (DGTs) for Hg were deployed in sediments to estimate the concentration of the toxicants in pore water. Analysis for (DDx) were performed using GC-MS. Accuracy was within ±30 % of the certified values and precision was >20 % relative standard deviation (RSD). Total mercury concentrations were determined using an automated Hg mercury analyzer. Precision was >5 % and accuracy was within ±10 % of certified values. The results of all the approaches (analysis of sediment, biota, and passive samplers) showed an increasing contamination from upstream to downstream sites. BSAF values revealed the bioavailability of both contaminants in the study sites, with values up to 49 for DDx and up to 3.1 for Hg. No correlation was found between values in sediments and the organisms. Concentrations calculated using passive samplers were correlated with values in benthic invertebrates, while no correlation was found with concentrations in sediments. Thus, direct analysis of toxicant in sediments does not provide a measurement of bioavailability. On the contrary

  6. Comparative chronic toxicity of homo- and heterocyclic aromatic compounds to benthic and terrestrial invertebrates: Generalizations and exceptions.

    NARCIS (Netherlands)

    Leon Paumen, M.; de Voogt, P.; van Gestel, C.A.M.; Kraak, M.H.S.

    2009-01-01

    The aim of the present study was to elucidate consistent patterns in chronic polycyclic aromatic compound (PAC) toxicity to soil and sediment inhabiting invertebrates. Therefore we examined our experimental dataset, consisting of twenty-one chronic effect concentrations for two soil invertebrates

  7. Comparative chronic toxicity of homo- and heterocyclic aromatic compounds to benthic and terrestrial invertebrates: Generalizations and exceptions

    NARCIS (Netherlands)

    León Paumen, M.; de Voogt, P.; van Gestel, C.A.M.; Kraak, M.H.S.

    2009-01-01

    The aim of the present study was to elucidate consistent patterns in chronic polycyclic aromatic compound (PAC) toxicity to soil and sediment inhabiting invertebrates. Therefore we examined our experimental dataset, consisting of twenty-one chronic effect concentrations for two soil invertebrates

  8. 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 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.

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

    Science.gov (United States)

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

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

  10. Spatio-temporal patterns in the coral reef communities of the Spermonde Archipelago, 2012–2014, II: Fish assemblages display structured variation related to benthic condition

    DEFF Research Database (Denmark)

    Plass-Johnson, Jeremiah Grahm; Teichberg, Mirta; Bednarz, Vanessa N.

    2018-01-01

    The Spermonde Archipelago is a complex of ~70 mostly populated islands off Southwest Sulawesi, Indonesia, in the center of the Coral Triangle. The reefs in this area are exposed to a high level of anthropogenic disturbances. Previous studies have shown that variation in the benthos is strongly...... with distance, while few species were present across the entire range of sites. Relating fish communities to benthic composition using a multivariate generalized linear model confirmed that fish groups relate to structural complexity (rugosity) or differing benthic groups; either algae, reef builders (coral...... and crustose coralline algae) or invertebrates and rubble. From these relationships we can identify sets of fish species that may be lost given continued degradation of the Spermonde reefs. Lastly, the incorporation of water quality, benthic and fish indices indicates that local coral reefs responded...

  11. Adaptation of benthic invertebrates to food sources along marine-terrestrial boundaries as indicated by carbon and nitrogen stable isotopes

    Science.gov (United States)

    Lange, G.; Haynert, K.; Dinter, T.; Scheu, S.; Kröncke, I.

    2018-01-01

    Frequent environmental changes and abiotic gradients of the Wadden Sea require appropriate adaptations of the local organisms and make it suitable for investigations on functional structure of macrozoobenthic communities from marine to terrestrial boundaries. To investigate community patterns and food use of the macrozoobenthos, a transect of 11 stations was sampled for species number, abundance and stable isotope values (δ13C and δ15N) of macrozoobenthos and for stable isotope values of potential food resources. The transect was located in the back-barrier system of the island of Spiekeroog (southern North Sea, Germany). Our results show that surface and subsurface deposit feeders, such as Peringia ulvae and different oligochaete species, dominated the community, which was poor in species, while species present at the transect stations reached high abundance. The only exception was the upper salt marsh with low abundances but higher species richness because of the presence of specialized semi-terrestrial and terrestrial taxa. The macrozoobenthos relied predominantly on marine resources irrespective of the locality in the intertidal zone, although δ13C values of the consumers decreased from - 14.1 ± 1.6‰ (tidal flats) to - 21.5 ± 2.4‰ (salt marsh). However, the ubiquitous polychaete Hediste diversicolor showed a δ15N enrichment of 2.8‰ (an increase of about one trophic level) from bare sediments to the first vegetated transect station, presumably due to switching from suspension or deposit feeding to predation on smaller invertebrates. Hence, we conclude that changes in feeding mode represent an important mechanism of adaptation to different Wadden Sea habitats.

  12. Influence of sediment quality on the responses of benthic invertebrates after treatment with the fungicide triphenyltin acetate

    NARCIS (Netherlands)

    Haas, de E.M.; Roessink, I.; Verbree, B.; Koelmans, A.A.; Kraak, M.H.S.; Admiraal, W.

    2005-01-01

    After decades of pollution, benthic communities in floodplain lake ecosystems are likely to be exposed to a diverse assortment of sediment-bound historical toxicants and nutrients as well as pulses of newly discharged or deposited toxicants. The aim of this study was therefore to analyze the effects

  13. Higher species richness and abundance of fish and benthic invertebrates around submarine groundwater discharge in Obama Bay, Japan

    OpenAIRE

    Tatsuya Utsunomiya; Masaki Hata; Ryo Sugimoto; Hisami Honda; Shiho Kobayashi; Yoji Miyata; Makoto Yamada; Osamu Tominaga; Jun Shoji; Makoto Taniguchi

    2017-01-01

    Study focus: There have been far more studies on how the variability in surface water discharge affects production of animal communities in aquatic ecosystems while less information has been accumulated on the mechanisms of how the groundwater supply works. Study region: Physical and biological surveys were conducted to test the hypothesis that high level of submarine ground water discharge enhances species richness, abundance and biomass of fishes and invertebrates in coastal waters of Ob...

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

    Science.gov (United States)

    Jessen, Christian; Voolstra, Christian R; Wild, Christian

    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 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.

  15. 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.

  16. 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.

  17. 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 1978-05-20 to 1979-01-15 (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...

  18. Mapping of marine benthic invertebrates in the Oslofjord and the Skagerrak: sampling data of museum collections from 1950-1955 and from recent investigations

    Directory of Open Access Journals (Sweden)

    Eivind Oug

    2015-12-01

    Full Text Available Data from large sampling programmes for the mapping of marine invertebrates in the Oslofjord, Norway, and the Skagerrak, spanning more than six decades, are compiled and digitized to provide easy access in modern data repositories. Two sampling programmes undertaken in the period 1950–55 are still the most extensive mapping of marine benthic fauna in the area. Information from a total of more than 900 localities, or sampling events, covering all benthic habitats in the Oslofjord and coastal waters to Kvitsøy in Rogaland county, have been carefully digitized from field notes, original sea charts, and primary observations from sample handling in the field. Geographical coordinates referred to WGS84 chart datum have been fixed with a general accuracy of 20 m in the Oslofjord and 100–250 m in coastal areas, based on precise map sketches with cross-bearings to land objects and chart annotations. Most samples were collected using triangular, Agassiz and lightweight dredges. The collected material has been deposited in the collections of the Natural History Museum, University of Oslo. Two recent projects, ‘Polyskag’ and ‘Bioskag’ (2006–2014, are briefly described. The projects focused on the diversity of marine bristle worms (Polychaeta, inter alia providing material for molecular genetic analyses. Type localities for early described species and generally understudied biotopes were visited. The data from the 1950s, together with recent studies, constitute a considerable resource for studies of biodiversity, facilitated through the sharing of species records from the museum collections in modern data repositories. The accurate positioning of sampling localities in the 1950s is of particular value for documenting species distributions over long time spans, thus providing a reference base for studying present and future species changes and assessing the effects of human influence and environmental changes in the Oslofjord and the Skagerrak.

  19. δ13C and δ15N shifts in benthic invertebrates exposed to sewage from McMurdo Station, Antarctica

    International Nuclear Information System (INIS)

    Conlan, Kathleen E. . E-mail kconlan@mus-nature.ca; Rau, Greg H.; Kvitek, Rikk G.

    2006-01-01

    In an effort to identify biomonitors for contamination of Antarctic marine benthos by sewage, this study determines whether the US Antarctic Program's McMurdo Station produces a benthic sewage footprint and whether resident megafauna are assimilating sewage-derived material. We identified strong C and N isotopic gradients in benthic sediment as a function of downstream distance from McMurdo Station's point-source sewage addition. Sediment C and N isotope ratios approached marine background levels at the sampling end-point 612 m downcurrent. Based on isotope abundances in their tissues, at least some sewage C and N were assimilated by the sedentary, suspension feeding soft coral Alcyonium antarcticum, ascidian Cnemidocarpa verrucosa and bivalve Laternula elliptica. However, as inferred by tissue-sediment differences in downstream isotope trends, such assimilation was not in proportion to sewage exposure and input, therefore implying non-generalist feeding behavior by these species. In contrast, the motile, generalist feeding sea urchin Sterechinus neumayeri, sea star Odontaster validus and ribbon worm Parborlasia corrugatus showed isotopic evidence of sewage C and N assimilation roughly in proportion to sewage input. We recommend these generalist feeders for further use as biomonitors at this site now that sewage treatment has been implemented. As these species are circumpolar in distribution, they may also prove useful elsewhere in the Antarctic

  20. Delta13C and delta15N shifts in benthic invertebrates exposed to sewage from McMurdo Station, Antarctica.

    Science.gov (United States)

    Conlan, Kathleen E; Rau, Greg H; Kvitek, Rikk G

    2006-12-01

    In an effort to identify biomonitors for contamination of Antarctic marine benthos by sewage, this study determines whether the US Antarctic Program's McMurdo Station produces a benthic sewage footprint and whether resident megafauna are assimilating sewage-derived material. We identified strong C and N isotopic gradients in benthic sediment as a function of downstream distance from McMurdo Station's point-source sewage addition. Sediment C and N isotope ratios approached marine background levels at the sampling end-point 612 m downcurrent. Based on isotope abundances in their tissues, at least some sewage C and N were assimilated by the sedentary, suspension feeding soft coral Alcyonium antarcticum, ascidian Cnemidocarpa verrucosa and bivalve Laternula elliptica. However, as inferred by tissue-sediment differences in downstream isotope trends, such assimilation was not in proportion to sewage exposure and input, therefore implying non-generalist feeding behavior by these species. In contrast, the motile, generalist feeding sea urchin Sterechinus neumayeri, sea star Odontaster validus and ribbon worm Parborlasia corrugatus showed isotopic evidence of sewage C and N assimilation roughly in proportion to sewage input. We recommend these generalist feeders for further use as biomonitors at this site now that sewage treatment has been implemented. As these species are circumpolar in distribution, they may also prove useful elsewhere in the Antarctic.

  1. 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

    1996-08-01

    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.

  2. Spatio-Temporal Patterns in the Coral Reef Communities of the Spermonde Archipelago, 2012–2014, II: Fish Assemblages Display Structured Variation Related to Benthic Condition

    Directory of Open Access Journals (Sweden)

    Jeremiah G. Plass-Johnson

    2018-02-01

    Full Text Available The Spermonde Archipelago is a complex of ~70 mostly populated islands off Southwest Sulawesi, Indonesia, in the center of the Coral Triangle. The reefs in this area are exposed to a high level of anthropogenic disturbances. Previous studies have shown that variation in the benthos is strongly linked to water quality and distance from the mainland. However, little is known about the fish assemblages of the region and if their community structure also follows a relationship with benthic structure and distance from shore. In this study, we used eight islands of the archipelago, varying in distance from 1 to 55 km relative to the mainland, and 3 years of surveys, to describe benthic and fish assemblages and to examine the spatial and temporal influence of benthic composition on the structure of the fish assemblages. Cluster analysis indicated that distinct groups of fish were associated with distance, while few species were present across the entire range of sites. Relating fish communities to benthic composition using a multivariate generalized linear model confirmed that fish groups relate to structural complexity (rugosity or differing benthic groups; either algae, reef builders (coral and crustose coralline algae or invertebrates and rubble. From these relationships we can identify sets of fish species that may be lost given continued degradation of the Spermonde reefs. Lastly, the incorporation of water quality, benthic and fish indices indicates that local coral reefs responded positively after an acute disturbance in 2013 with increases in reef builders and fish diversity over relatively short (1 year time frames. This study contributes an important, missing component (fish community structure to the growing literature on the Spermonde Archipelago, a system that features environmental pressures common in the greater Southeast Asian region.

  3. Guidelines for the processing and quality assurance of benthic invertebrate samples collected as part of the National Water-Quality Assessment Program

    Science.gov (United States)

    Cuffney, T.F.; Gurtz, M.E.; Meador, M.R.

    1993-01-01

    Benthic invertebrate samples are collected as part of the U.S. Geological Survey's National Water-Quality Assessment Program. This is a perennial, multidisciplinary program that integrates biological, physical, and chemical indicators of water quality to evaluate status and trends and to develop an understanding of the factors controlling observed water quality. The Program examines water quality in 60 study units (coupled ground- and surface-water systems) that encompass most of the conterminous United States and parts of Alaska and Hawaii. Study-unit teams collect and process qualitative and semi-quantitative invertebrate samples according to standardized procedures. These samples are processed (elutriated and subsampled) in the field to produce as many as four sample components: large-rare, main-body, elutriate, and split. Each sample component is preserved in 10-percent formalin, and two components, large-rare and main-body, are sent to contract laboratories for further processing. The large-rare component is composed of large invertebrates that are removed from the sample matrix during field processing and placed in one or more containers. The main-body sample component consists of the remaining sample materials (sediment, detritus, and invertebrates) and is subsampled in the field to achieve a volume of 750 milliliters or less. The remaining two sample components, elutriate and split, are used for quality-assurance and quality-control purposes. Contract laboratories are used to identify and quantify invertebrates from the large-rare and main-body sample components according to the procedures and guidelines specified within this document. These guidelines allow the use of subsampling techniques to reduce the volume of sample material processed and to facilitate identifications. These processing procedures and techniques may be modified if the modifications provide equal or greater levels of accuracy and precision. The intent of sample processing is to

  4. Environmental niche separation between native and non-native benthic invertebrate species: Case study of the northern Baltic Sea.

    Science.gov (United States)

    Jänes, Holger; Herkül, Kristjan; Kotta, Jonne

    2017-10-01

    Knowledge and understanding of geographic distributions of species is crucial for many aspects in ecology, conservation, policy making and management. In order to reach such an understanding, it is important to know abiotic variables that impact and drive distributions of native and non-native species. We used an existing long-term macrobenthos database for species presence-absence information and biomass estimates at different environmental gradients in the northern Baltic Sea. Region specific abiotic variables (e.g. salinity, depth) were derived from previously constructed bathymetric and hydrodynamic models. Multidimensional ordination techniques were then applied to investigate potential niche space separation between all native and non-native invertebrates in the northern Baltic Sea. Such an approach allowed to obtain data rich and robust estimates of the current native and non-native species distributions and outline important abiotic parameters influencing the observed pattern. The results showed clear niche space separation between native and non-native species. Non-native species were situated in an environmental space characterized by reduced salinity, high temperatures, high proportion of soft seabed and decreased depth and wave exposure whereas native species displayed an opposite pattern. Different placement of native and non-native species along the studied environmental niche space is likely to be explained by the differences in their evolutionary history, human mediated activities and geological youth of the Baltic Sea. The results of this study can provide early warnings and effectively outline coastal areas in the northern Baltic Sea that are prone to further range expansion of non-native species as climate change is expected to significantly reduce salinity and increase temperature in wide coastal areas, both supporting the disappearance of native and appearance of non-native species. Copyright © 2017 Elsevier Ltd. All rights reserved.

  5. 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

  6. 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,...

  7. Invertebrate lamins

    International Nuclear Information System (INIS)

    Melcer, Shai; Gruenbaum, Yosef; Krohne, Georg

    2007-01-01

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

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

    International Nuclear Information System (INIS)

    Galar Martinez, Marcela; Martinez-Tabche, Laura; Sanchez-Hidalgo, Eugenia; Lopez Lopez, Eugenia

    2006-01-01

    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

  9. Spiders in Motion: Demonstrating Adaptation, Structure-Function Relationships, and Trade-Offs in Invertebrates

    Science.gov (United States)

    Bowlin, Melissa S.; McLeer, Dorothy F.; Danielson-Francois, Anne M.

    2014-01-01

    Evolutionary history and structural considerations constrain all aspects of animal physiology. Constraints on invertebrate locomotion are especially straightforward for students to observe and understand. In this exercise, students use spiders to investigate the concepts of adaptation, structure-function relationships, and trade-offs. Students…

  10. A closer look at the main actors of Neotropical floodplain food webs: functional classification and niche overlap of dominant benthic invertebrates in a floodplain lake of Paraná River

    Directory of Open Access Journals (Sweden)

    Miguel Saigo

    2016-01-01

    Full Text Available ABSTRACT Functional classification of animals is necessary to enhance the predictive power of food web models. However, while there is a large database for functional classification of benthic invertebrates (Functional Feeding Groups, FFG in the temperate zone, the attribution of individual species of riverine invertebrates is still in its infancies in the Neotropical Region. Different authors hypothesized that diet breadth was larger in the Tropics, however detailed analysis are scarce. In the present study we aimed at classifying dominant benthic taxa of the Middle Paraná River floodplain (Argentina into trophic guilds by diet and niche overlap analyses. We sampled twelve taxa of benthic invertebrates from a floodplain lake during low water season and performed a gut content analysis as a baseline for FFG classification. We also used available diet information of other common taxa for statistical analysis. Then, we compared the variance of niche overlap, using Pianka's index, with that of simulated null model. After that we grouped taxa using Morisita similarity index with a threshold of 0.6 and compared niche overlap with null models within and between FFGs. Observed variance of niche overlap was greater than expected by chance, confirming the presence of FFGs among analyzed taxa. Considering trophic similarity of species, we identified four FFGs: collectors, omnivores, herbivores and predators. Niche overlap was greater than expected by stochastic null models within FFGs, and smaller between FFGs. Nearly one third of analyzed taxa were classified in a different FFG than their congeners of the Holarctic region. This result indicates that classifications performed in the Holarctic region should be used with care in the Neotropical region, even in subtropical systems

  11. Trophic structure and feeding rates of forest soil invertebrate populations

    Energy Technology Data Exchange (ETDEWEB)

    McBrayer, J F; Reichle, D E

    1971-01-01

    Trophic level relationships of a soil invertebrate community were determined using the transient behavior of cesium-137 in experimental soil microcosms. Feeding rates were estimated from radionuclide mass balance equations using radiocesium uptake coefficients, equilibrium concentrations of /sup 137/Cs in consumers, and /sup 137/Cs composition of food bases. The fungivore trophic level included Scatopsidae larvae (Diptera), Enchytraeida (Annelida), Entomobryidae and Onychiuridae (Collembola), Rhodacaridae (Mesostigmata), and Oribatulidae, Camasiidae, Carabodidae, and Cymbaeremaeidae (Oribatei). Approximately 60% of the total faunal biomass occurred in the fungivore trophic level. Fungivores averaged 7.0 +/- 2.4% dry body weight ingested per day. Cecidomyiidae larvae (Diptera), Diplopoda, Isotomidae (Collembola), Uropodina, and Phthiracaridae (Oribatei) were determined to be surface-feeding saprophages. Subsurface-feeding saprophages included Symphyla, Cillibidae (Uropidina), and Palaeacaridae and Epilohmannidae (Oribatei). Surface-feeding saprophages averaged 1.0 +/- 0.4% dry body weight ingested per day. Feeding rates were not calculated for saprophages feeding within the mineral soil horizon. Predators included Dolichopodidae larvae (Diptera), gamasine mites, and the Scutacaridae and other prostigmatid mites. Predators averaged 2.5 +/- 1.0% dry body weight ingested per day. 15 references, 3 figures, 3 tables.

  12. Benthic invertebrate fauna, small streams

    Science.gov (United States)

    J. Bruce Wallace; S.L. Eggert

    2009-01-01

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

  13. 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)

  14. The Impact of Epifaunal Predation on the Structure of Macroinfaunal Invertebrate Communities of Tidal Saltmarsh Creeks

    Science.gov (United States)

    Sardá, R.; Foreman, K.; Werme, C. E.; Valiela, I.

    1998-05-01

    The impact of epibenthic predators foraging on macroinfaunal communities was analysed in Great Sippewissett salt marsh (MA, U.S.A.) by installing experimental cages in the most productive sediments of the marsh (77 g dry weight m -2year -1). The most productive macroinfaunal species in these sediments were Marenzelleria viridis(43·1 g dry weight m -2year -1) Heteromastus filiformis(13·7 g dry weight m -2year -1) and Neanthes arenaceodonta(7·6 g dry weight m -2year -1). Macroinfaunal densities peaked in June following the spring recruitment. Density and biomass inside the cages were significantly higher during the growing season, however, density declined in July and August following the seasonal cycle observed outside cages, while biomass did not suffer this decline. The absence of epibenthic predators favored growth and accumulation of larger organisms, especially M. viridis, and included higher presence of predaceous infauna ( Glycera americana, Neanthes succinea, Neanthes virens, Eteone heteropodaand Nemerteans). At the end of the experiment, there was 22·2 g dry weight m -2more macroinfaunal biomass in the complete cages than in ambient sediments. The absence of epibenthic predators also increased secondary production; M. viridisdoubled production in the sediments inside cages compared with outside cages. The most common benthic predaceous fishes in the marsh were the killifishes, Fundulus heteroclitusand Fundulus majalis, and some seasonal invasive fishes ( Gasterosteus aculeatus, Tautoga onitis, Centropristes striatusand Pleuronectes americanus). While invasive fishes preyed mainly on benthic invertebrates and grew faster, resident fishes shifted their diets through the season. The values of macroinfaunal secondary production obtained in these sediments can support the energy requirements of the predators of the marsh; in this way the pulse of secondary production created by the macroinfaunal populations travels up the saltmarsh food web.

  15. 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.

  16. Community structure and abundance of benthic infaunal invertebrates in Maine fringing marsh ecosystems

    Science.gov (United States)

    Richard A. MacKenzie; Michele Dionne; Jeremy Miller; Michael Haas; Pamela A. Morgan

    2015-01-01

    Fringing marshes are abundant ecosystems that dominate the New England coastline. Despite their abundance, very little baseline data is available from them and few studies have documented the ecosystems services that they provide. This information is important for conservation efforts as well as for an increased understanding of how fringing marshes function compared...

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

    Science.gov (United States)

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

    2015-01-01

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

  18. 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.

  19. Glycosaminoglycans analogues from marine invertebrates: structure, biological effects and potential as new therapeutics.

    Directory of Open Access Journals (Sweden)

    Mauro Sergio Pavao

    2014-09-01

    Full Text Available In this review, several glycosaminoglycan analogs obtained from different marine invertebrate are reported. The structure, biological activity and mechanism of action of these unique molecules are detailed reviewed and exemplified by experiments in vitro and in vivo. Among the glycans studied are low-sulfated heparin-like polymers from ascidians, containing significant anticoagulant activity and no bleeding effect; dermatan sulfates with significant neurite outgrowth promoting activity and anti-P-selectin from ascidians, and a unique fucosylated chondroitin sulfate from sea cucumbers, possessing anticoagulant activity after oral administration and high anti P- and L-selectin activities. The therapeutic value and safety of these invertebrate glycans have been extensively proved by several experimental animal models of diseases, including thrombosis, inflammation and metastasis. These invertebrate glycans can be obtained in high concentrations from marine organisms that have been used as a food source for decades, and usually obtained from marine farms in sufficient quantities to be used as starting material for new therapeutics.

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

    Science.gov (United States)

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

    2015-11-01

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

  1. 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

  2. Community structure and Distribution of Phytomacrofauna in Iyagbe ...

    African Journals Online (AJOL)

    ADOWIE PERE

    Benthic Ecology Unit, Department of Marine Sciences, University of Lagos Akoka, Lagos, Nigeria. *Corresponding author: ... such as fishes and invertebrates can also be affected, ...... Lake Vechten: structural and functional relationships.

  3. Effects of fishing disturbance on benthic communities and secondary production within an intensively fished area

    NARCIS (Netherlands)

    Reiss, H.; Greenstreet, S.P.R.; Sieben, K.; Ehrich, S.; Piet, G.J.; Quirijns, F.; Wolff, W.J.; Kroncke, I.

    2009-01-01

    Demersal fishing alters seabed habitats and affects the structure and functioning of benthic invertebrate communities. At a critical level of disturbance, such communities may approach an equilibrium disturbed state in which a further increase in disturbance has little additional impact. Such

  4. 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.

  5. Benthic community structure on coral reefs exposed to intensive recreational snorkeling.

    Directory of Open Access Journals (Sweden)

    Bobbie Renfro

    Full Text Available Chronic anthropogenic disturbances on coral reefs in the form of overfishing and pollution can shift benthic community composition away from stony corals and toward macroalgae. The use of reefs for recreational snorkeling and diving potentially can lead to similar ecological impacts if not well-managed, but impacts of snorkeling on benthic organisms are not well understood. We quantified variation in benthic community structure along a gradient of snorkeling frequency in an intensively-visited portion of the Mesoamerican Barrier Reef. We determined rates of snorkeling in 6 water sections and rates of beach visitation in 4 adjacent land sections at Akumal Bay, Mexico. For each in-water section at 1-3 m depth, we also assessed the percent cover of benthic organisms including taxa of stony corals and macroalgae. Rates of recreational snorkeling varied from low in the southwestern to very high (>1000 snorkelers d-1 in the northeastern sections of the bay. Stony coral cover decreased and macroalgal cover increased significantly with levels of snorkeling, while trends varied among taxa for other organisms such as gorgonians, fire corals, and sea urchins. We conclude that benthic organisms appear to exhibit taxon-specific variation with levels of recreational snorkeling. To prevent further degradation, we recommend limitation of snorkeler visitation rates, coupled with visitor education and in-water guides to reduce reef-damaging behaviors by snorkelers in high-use areas. These types of management activities, integrated with reef monitoring and subsequent readjustment of management, have the potential to reverse the damage potentially inflicted on coral reefs by the expansion of reef-based recreational snorkeling.

  6. Watermass structure at benthic disturbance site (INDEX area) and anticipated mining effects on hydro-physical properties

    Digital Repository Service at National Institute of Oceanography (India)

    RameshBabu, V.; Murty, V.S.N.; Suryanarayana, A.; Beena, B.S.; Niranjan, K,

    Watermass properties were obtained in the Indian Deep Sea Experiment (INDEX) area during pre- (27 May-8 July 1997) and post- (22 July-5 September, 1997) benthic disturbance periods respectively. Watermass (Temperature-Salinity: T-S) structure...

  7. Evaluation of potential relationships between benthic community structure and toxic metals in Laizhou Bay.

    Science.gov (United States)

    Wu, Bin; Song, Jinming; Li, Xuegang

    2014-10-15

    The objective of the present study was to examine the relationships between benthic community structure and toxic metals using bivariate/multivariate techniques at 17 sediment locations in Laizhou Bay, North China. Sediment chemical data were evaluated against geochemical background values and sediment quality guidelines, which identified Cu and As as contaminants of concern with a moderate potential for adverse effects. Benthic community data were subjected to non-metric multidimensional scaling, which generated four groups of stations. Spearman rank correlation was then employed to explore the relationships between the major axes of heavy metals and benthic community structure. However, weak and insignificant correlations were found between these axes, indicating that contaminants of concern may not be the primary explanatory factors. Polychaeta were abundant in southern Laizhou Bay, serving as a warning regarding the health status of the ecosystem. Integrated sediment quality assessment showed sediments from northern central locations were impaired, displaying less diverse benthos and higher metal contamination. Copyright © 2014 Elsevier Ltd. All rights reserved.

  8. {delta}{sup 13}C and {delta}{sup 15}N shifts in benthic invertebrates exposed to sewage from McMurdo Station, Antarctica

    Energy Technology Data Exchange (ETDEWEB)

    Conlan, Kathleen E. [Canadian Musem of Nature, P.O. Box 3443 Station D, Ottawa, Ont., K1P 6P4 (Canada)]. E-mail kconlan@mus-nature.ca; Rau, Greg H. [Institute of Marine Sciences, University of California, Santa Cruz, CA 95064 (United States); Kvitek, Rikk G. [Earth Systems Science and Policy, California State University Monterey Bay, 100 Campus Center, Seaside, CA 93955 (United States)

    2006-12-15

    In an effort to identify biomonitors for contamination of Antarctic marine benthos by sewage, this study determines whether the US Antarctic Program's McMurdo Station produces a benthic sewage footprint and whether resident megafauna are assimilating sewage-derived material. We identified strong C and N isotopic gradients in benthic sediment as a function of downstream distance from McMurdo Station's point-source sewage addition. Sediment C and N isotope ratios approached marine background levels at the sampling end-point 612 m downcurrent. Based on isotope abundances in their tissues, at least some sewage C and N were assimilated by the sedentary, suspension feeding soft coral Alcyonium antarcticum, ascidian Cnemidocarpa verrucosa and bivalve Laternula elliptica. However, as inferred by tissue-sediment differences in downstream isotope trends, such assimilation was not in proportion to sewage exposure and input, therefore implying non-generalist feeding behavior by these species. In contrast, the motile, generalist feeding sea urchin Sterechinus neumayeri, sea star Odontaster validus and ribbon worm Parborlasia corrugatus showed isotopic evidence of sewage C and N assimilation roughly in proportion to sewage input. We recommend these generalist feeders for further use as biomonitors at this site now that sewage treatment has been implemented. As these species are circumpolar in distribution, they may also prove useful elsewhere in the Antarctic.

  9. Colonisation and community structure of benthic diatoms on artificial ...

    African Journals Online (AJOL)

    This was undertaken using tiles as artificial substrates so that we could study how the communities developed after the flood disturbance. The diatom community structure was assessed over a 28-day period following a flood event in October 2012. The Mann Whitney test indicated that there was a statistically significant ...

  10. Historical changes in the structure and functioning of the benthic community in the lagoon of Venice

    Science.gov (United States)

    Pranovi, Fabio; Da Ponte, Filippo; Torricelli, Patrizia

    2008-03-01

    One of the main challenges in environmental management is how to manage the dynamics of natural environments. In this context, having information about historical changes of the structure of the biological communities could represent a useful tool to improve management strategies, contributing to refine the policy objectives, since it gives reference states with which to compare the present. The Venice lagoon represents an interesting case study, since it is a highly dynamic, but sensitive, environment which requires the adoption of prudent management. In its recent history the lagoon ecosystem has been exposed to different kinds of disturbance, from the discharge of pollutants and nutrients, to the invasion of alien species and the exploitation of its biological resources by using highly impacting fishing gears. The analysis of available data about the macro-benthic community, from 1935 to 2004, allows the description of changes of the community structure over almost 70 years, showing a sharp decrease in its diversity. In order to obtain information about its functioning, it is necessary to know how these changes have affected processes at the community and system level. In shallow water ecosystems, as the control is mainly due to the benthic compartment, variations in the structure of the benthic community can induce modifications in processes at different hierarchical levels. The trophic structure analysis has revealed major changes during the period; from a well-assorted structure in 1935, to an herbivore-detritivore dominated one in the 1990s, and finally to a filter feeder dominated structure during the last decade. This has produced variations in the secondary production and it has induced modifications in the type of the ecosystem control. These changes are discussed in the light of the dynamics of the main driving forces.

  11. Environmental and Spatial Influences on Biogeography and Community Structure of Benthic Diatoms

    Science.gov (United States)

    Plante, C.; Hill-Spanik, K.; Lowry, J.

    2016-02-01

    Several theoretical and practical reasons suggest that benthic microalgae could be useful bioindicators. For instance, an ideal indicator species or community would be associated with a given habitat due to local physical conditions or biotic interactions (i.e., `environmental filtering'), not due to dispersal limitation. Due to their small size, immense abundances, and reliance on passive dispersal, the popular notion about micro-organisms is that `Everything is everywhere, but, the environment selects' (Baas-Becking 1934). Although much recent research concerning planktonic bacteria and dispersal limitation has been conducted, very little in this regard is known about microeukaryotes, especially benthic microbes. The purpose of our study was to identify and compare spatial and environmental influences on benthic diatom community structure and biogeography. In summer 2015, sediment was sampled at various spatial scales from four barrier island beaches in South Carolina, USA, and high-throughput (Ion Torrent) DNA sequencing was used to characterize diatom assemblages. ANOSIM and principal coordinates analysis revealed that communities were statistically distinct on the four islands. Community dissimilarity was compared to both spatial distance and environmental differences to determine potential influences of these variables on community structure. We found that geographic distance had the strongest correlation with community similarity, with and without one anomalous location, while differences in temperature (air, water, and sediment), nutrients, organic matter, and turbidity also had significant but weaker relationships with community structure. Surprisingly, air temperature, which changes on very short time scales, appeared to be the environmental factor most strongly related to diatom species composition, potentially implicating some unmeasured variable (e.g., cloud cover). However, we also found that temperature and geographic distance were strongly

  12. Structural insights from a novel invertebrate triosephosphate isomerase from Litopenaeus vannamei

    Science.gov (United States)

    Lopez-Zavala, Alonso A.; Carrasco-Miranda, Jesus S.; Ramirez-Aguirre, Claudia D.; López-Hidalgo, Marisol; Benitez-Cardoza, Claudia G.; Ochoa-Leyva, Adrian; Cardona-Felix, Cesar S.; Diaz-Quezada, Corina; Rudiño-Piñera, Enrique; Sotelo-Mundo, Rogerio R.; Brieba, Luis G.

    2016-01-01

    Triosephosphate isomerase (TIM; EC 5.3.1.1) is a key enzyme involved in glycolysis and gluconeogenesis. Glycolysis is one of the most regulated metabolic pathways, however little is known about the structural mechanisms for its regulation in non-model organisms, like crustaceans. To understand the structure and function of this enzyme in invertebrates, we obtained the crystal structure of triosephosphate isomerase from the marine Pacific whiteleg shrimp (Litopenaeus vannamei, LvTIM) in complex with its inhibitor 2-phosphogyceric acid (2-PG) at 1.7 Å resolution. LvTIM assembles as a homodimer with residues 166-176 covering the active site and residue Glu166 interacting with the inhibitor. We found that LvTIM is the least stable TIM characterized to date, with the lowest range of melting temperatures, and with the lowest activation enthalpy associated with the thermal unfolding process reported. In TIMs dimer stabilization is maintained by an interaction of loop 3 by a set of hydrophobic contacts between subunits. Within these contacts, the side chain of a hydrophobic residue of one subunit fits into a cavity created by a set of hydrophobic residues in the neighboring subunit, via a "ball and socket" interaction. LvTIM presents a Cys47 at the "ball" inter-subunit contact indicating that the character of this residue is responsible for the decrease in dimer stability. Mutational studies show that this residue plays a role in dimer stability but is not a solely determinant for dimer formation. PMID:27614148

  13. The role of pelagic-benthic coupling in structuring littoral benthic communities at Terra Nova Bay (Ross Sea and in the Straits of Magellan

    Directory of Open Access Journals (Sweden)

    Riccardo Cattaneo-Vietti

    1999-12-01

    Full Text Available In Antarctic and peri-Antarctic regions, benthic communities are persistent in time and show high biomass and large numbers of individuals, mainly consisting of suspension and deposit feeders. In fact, apart from recruitment, the major factor structuring these communities is the high flow of organic matter from the pelagic domain to the bottom, representing an important energy source for the benthic organisms. The aim of this paper is to review, compile and compare the data from earlier investigations in Terra Nova Bay (Ross Sea and the Straits of Magellan, in order to come to a more general conclusion about the role of the pelagic-benthic coupling in structuring littoral benthic communities in southern coastal areas. Few measurements of flux rates and the biochemical composition of the sinking particles occurring in Antarctic and peri-Antarctic shallow waters are available, but a compilation of our own data and others allows a comparison of these two systems. The different environmental conditions between Antarctica and the Straits of Magellan lead to differences in the origin of the particulate organic matter and in its biochemical composition, and consequently in the coupling between pelagic and benthic domains. At Terra Nova Bay the summer particulate matter shows a high labile fraction of a good food value: its flux has been evaluated at about 0.67 g m-2d-1. Conversely, the Straits of Magellan show multi-structured ecosystems where the quality and quantity of the organic matter flux towards the bottom change according to the local geomorphology and current dynamics. Moreover, the three-dimensional assemblages of suspension-feeders, so common in Antarctic shallow waters, seem to be absent in the Magellan area. In particular sponges, gorgonarians and bryozoans play a secondary role inside the Straits of Magellan, where polychaetes (60% and molluscs (9-10% are dominant on soft bottoms, and where they reach high values in density and biomass

  14. 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. Copyright © 2016 Elsevier Inc. All rights reserved.

  15. Linking the planktonic and benthic habitat: genetic structure of the marine diatom Skeletonema marinoi.

    Science.gov (United States)

    Godhe, Anna; Härnström, Karolina

    2010-10-01

    Dormant life stages are important strategies for many aquatic organisms. The formation of resting stages will provide a refuge from unfavourable conditions in the water column, and their successive accumulation in the benthos will constitute a genetic reservoir for future planktonic populations. We have determined the genetic structure of a common bloom-forming diatom, Skeletonema marinoi, in the sediment and the plankton during spring, summer and autumn two subsequent years (2007-2009) in Gullmar Fjord on the Swedish west coast. Eight polymorphic microsatellite loci were used to assess the level of genetic differentiation and the respective gene diversity of the two different habitats. We also determined the degree of genetic differentiation between the seed banks inside the fjord and the open sea. The results indicate that Gullmar Fjord has one dominant endogenous population of S. marinoi, which is genetically differentiated from the open sea population. The fjord population is encountered in the plankton and in the sediment. Shifts from the dominant population can happen, and in our study, two genetically differentiated plankton populations, displaying reduced genetic diversity, occurred in September 2007 and 2008. Based on our results, we suggest that sill fjords maintain local long-lived and well-adapted protist populations, which continuously shift between the planktonic and benthic habitats. Intermittently, short-lived and mainly asexually reproducing populations can replace the dominant population in the water column, without influencing the genetic structure of the benthic seed bank. © 2010 Blackwell Publishing Ltd.

  16. Benthic data for corals, macroalgae, invertebrates, and non-living bottom types from Fagatele Bay National Marine Sanctuary, South Pacific Ocean, 2007-04-02 to 2008-12-31 (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,...

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

    Science.gov (United States)

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

  18. 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

  19. Distance, dams and drift: What structures populations of an endangered, benthic stream fish?

    Science.gov (United States)

    Roberts, James H.; Angermeier, Paul; Hallerman, Eric M.

    2013-01-01

    Spatial population structure plays an important role in species persistence, evolution and conservation. Benthic stream fishes are diverse and frequently imperilled, yet the determinants and spatial scaling of their population structure are understudied. We investigated the range-wide population genetic structure of Roanoke logperch (Percina rex), an endangered, benthic stream fish of the eastern United States. Fish were sampled from 35 sites and analysed at 11 microsatellite DNA loci. Clustering models were used to sort individuals into genetically cohesive groups and thereby estimate the spatial scaling of population structure. We then used Bayesian generalized linear mixed models (BGLMMs) to test alternative hypotheses about the environmental factors most responsible for generating structure, as measured by the differentiation statistic FST. Clustering models delineated seven discrete populations, whose boundaries coincided with agents of fragmentation, including hydroelectric dams and tailwaters. In the absence of hydrological barriers, gene flow was extensive throughout catchments, whereas there was no evidence for contemporary dispersal between catchments across barriers. In the best-supported BGLMM, FST was positively related to the spatial distance and degree of hydrological alteration between sites and negatively related to genetic diversity within sites. Whereas the effect of tailwaters was equivocal, dams strongly influenced differentiation: the effect of a dam on FST was comparable to that of a between-site distance of over 1200 km of unimpounded river. Overall, the effect of distance-mediated dispersal was negligible compared to the combined effects of fragmentation and genetic drift. The contemporary population structure of P. rex comprises a few geographically extensive ‘islands’ that are fragmented by hydroelectric projects. This information clarifies the importance of a catchment-scale perspective on conserving the species and

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

    Directory of Open Access Journals (Sweden)

    Alfonso Nebra

    2011-04-01

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

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

    Science.gov (United States)

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

    2018-01-15

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

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

    Science.gov (United States)

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

    2005-05-01

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

  3. Invertebrate biomechanics.

    Science.gov (United States)

    Patek, S N; Summers, A P

    2017-05-22

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

  4. 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....

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

    Science.gov (United States)

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

    2013-07-01

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

  6. 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.

  7. Coastal habitats as surrogates for taxonomic, functional and trophic structures of benthic faunal communities.

    Science.gov (United States)

    Törnroos, Anna; Nordström, Marie C; Bonsdorff, Erik

    2013-01-01

    Due to human impact, there is extensive degradation and loss of marine habitats, which calls for measures that incorporate taxonomic as well as functional and trophic aspects of biodiversity. Since such data is less easily quantifiable in nature, the use of habitats as surrogates or proxies for biodiversity is on the rise in marine conservation and management. However, there is a critical gap in knowledge of whether pre-defined habitat units adequately represent the functional and trophic structure of communities. We also lack comparisons of different measures of community structure in terms of both between- (β) and within-habitat (α) variability when accounting for species densities. Thus, we evaluated a priori defined coastal habitats as surrogates for traditional taxonomic, functional and trophic zoobenthic community structure. We focused on four habitats (bare sand, canopy-forming algae, seagrass above- and belowground), all easily delineated in nature and defined through classification systems. We analyzed uni- and multivariate data on species and trait diversity as well as stable isotope ratios of benthic macrofauna. A good fit between habitat types and taxonomic and functional structure was found, although habitats were more similar functionally. This was attributed to within-habitat heterogeneity so when habitat divisions matched the taxonomic structure, only bare sand was functionally distinct. The pre-defined habitats did not meet the variability of trophic structure, which also proved to differentiate on a smaller spatial scale. The quantification of trophic structure using species density only identified an epi- and an infaunal unit. To summarize the results we present a conceptual model illustrating the match between pre-defined habitat types and the taxonomic, functional and trophic community structure. Our results show the importance of including functional and trophic aspects more comprehensively in marine management and spatial planning.

  8. Benthic macrofaunal structure and secondary production in tropical estuaries on the Eastern Marine Ecoregion of Brazil.

    Science.gov (United States)

    Bissoli, Lorena B; Bernardino, Angelo F

    2018-01-01

    Tropical estuaries are highly productive and support diverse benthic assemblages within mangroves and tidal flats habitats. Determining differences and similarities of benthic assemblages within estuarine habitats and between regional ecosystems may provide scientific support for management of those ecosystems. Here we studied three tropical estuaries in the Eastern Marine Ecoregion of Brazil to assess the spatial variability of benthic assemblages from vegetated (mangroves) and unvegetated (tidal flats) habitats. A nested sampling design was used to determine spatial scales of variability in benthic macrofaunal density, biomass and secondary production. Habitat differences in benthic assemblage composition were evident, with mangrove forests being dominated by annelids (Oligochaeta and Capitellidae) whereas peracarid crustaceans were also abundant on tidal flats. Macrofaunal biomass, density and secondary production also differed between habitats and among estuaries. Those differences were related both to the composition of benthic assemblages and to random spatial variability, underscoring the importance of hierarchical sampling in estuarine ecological studies. Given variable levels of human impacts and predicted climate change effects on tropical estuarine assemblages in Eastern Brazil, our data support the use of benthic secondary production to address long-term changes and improved management of estuaries in Eastern Brazil.

  9. Roebuck Bay Invertebrate and bird Mapping 2006

    NARCIS (Netherlands)

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

    2006-01-01

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

  10. Dominant Benthic Structure and Biological Cover Habitat Maps for West Maui and West Hawaii

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — Benthic habitat maps depict dominant substrate type and biological cover in depths between 0 and ~150 m for two priority sites in the Main Hawaiian Islands; the NOAA...

  11. Benthic macroinvertebrate community structure and distribution in the Ayeyarwady continental shelf, Andaman Sea

    Digital Repository Service at National Institute of Oceanography (India)

    Ansari Z.A.; Furtado, R.; Badesab, S.; Mehta, P.; Thwin, S.

    water, Myanmar] Introduction Abundance of benthic fauna is one of the biological indices that support the food chain hypothesis of overall productivity in marine ecosystem1. Changes in benthic community may occur on different spatial scale..., biomass and species diversity of macrobenthos was more in the inshore waters than in the offshore areas of Malaysia and Gulf of Thailand. As indicated earlier, a significant amount of the variation in faunal abundances, not unexpectedly, is a function...

  12. Benthic habitat and fish assemblage structure from shallow to mesophotic depths in a storm-impacted marine protected area

    Science.gov (United States)

    Abesamis, Rene A.; Langlois, Tim; Birt, Matthew; Thillainath, Emma; Bucol, Abner A.; Arceo, Hazel O.; Russ, Garry R.

    2018-03-01

    Baseline ecological studies of mesophotic coral ecosystems are lacking in the equatorial Indo-West Pacific region where coral reefs are highly threatened by anthropogenic and climate-induced disturbances. Here, we used baited remote underwater video to describe benthic habitat and fish assemblage structure from 10 to 80 m depth at Apo Island, a well-managed marine protected area in the Philippines. We conducted surveys 2 yr after two storms (in 2011 and 2012) caused severe damage to shallow coral communities within the no-take marine reserve (NTMR) of Apo Island, which led to declines in fish populations that had built up over three decades. We found that hard coral cover was restricted to the storm-impacted NTMR and a nearby fished area not impacted by storms. Benthic cover at mesophotic depths (> 30 m) was dominated by sand/rubble and rock (dead coral) with low cover of soft corals, sponges and macroalgae. Storm damage appeared to have reached the deepest limit of the fringing reef (40 m) and reduced variability in benthic structure within the NTMR. Species richness and/or abundance of most trophic groups of fish declined with increasing depth regardless of storm damage. There were differences in taxonomic and trophic structure and degree of targeting by fisheries between shallow and mesophotic fish assemblages. Threatened shark species and a fish species previously unreported in the Philippines were recorded at mesophotic depths. Our findings provide a first glimpse of the benthic and fish assemblage structure of Philippine coral reef ecosystems across a wide depth gradient. This work also underscores how a combination of limited coral reef development at mesophotic depths close to shallow reefs and severe habitat loss caused by storms would result in minimal depth refuge for reef fish populations.

  13. Attraction Pheromone of The Benthic Diatom Seminavis robusta: Studies on Structure-Activity Relationships.

    Science.gov (United States)

    Lembke, Christine; Stettin, Daniel; Speck, Franziska; Ueberschaar, Nico; De Decker, Sam; Vyverman, Wim; Pohnert, Georg

    2018-04-01

    Recently the first pheromone of a marine diatom was identified to be the diketopiperazine (S,S)-diproline. This compound facilitates attraction between mating partners in the benthic diatom Seminavis robusta. Interestingly, sexualized S. robusta cells are attracted to both the natural pheromone (S,S)-diproline as well as to its enantiomer (R,R)-diproline. Usually stereospecificity is a prerequisite for successful substrate-receptor interactions, and especially pheromone perception is often highly enantioselective. Here we introduce a structure-activity relationship study, to learn more about the principles of pheromone reception in diatoms. We analyzed the activity of nine different diketopiperazines in attraction and interference assays. The pheromone diproline itself, as well as a pipecolic acid derived diketopiperazine with two expanded aliphatic ring systems, showed the highest attractivity. Hydroxylatoin of the aliphatic rings abolished any bioactivity. Diketopiperazines derived from acyclic amino acids were not attrative as well. All stereoisomers of both the diproline and the pipecolic acid derived diketopiperazine were purified by enantioselective high-performance liquid chromatography, and application in bioactivity tests confirmed that attraction pheromone perception in this diatom is indeed not stereospecific. However, the lack of activity of diketopiperazines derived from acyclic amino acids suggests a specificity that prevents misguidance to sources of other naturally occurring diketopiperazines.

  14. Natural disturbance shapes benthic intertidal macroinvertebrate communities of high latitude river deltas

    Science.gov (United States)

    Churchwell, Roy T.; Kendall, Steve J.; Blanchard, Amy L.; Dunton, Kenneth H.; Powell, Abby N.

    2016-01-01

    Unlike lower latitude coastlines, the estuarine nearshore zones of the Alaskan Beaufort Sea are icebound and frozen up to 9 months annually. This annual freezing event represents a dramatic physical disturbance to fauna living within intertidal sediments. The main objectives of this study were to describe the benthic communities of Beaufort Sea deltas, including temporal changes and trophic structure. Understanding benthic invertebrate communities provided a baseline for concurrent research on shorebird foraging ecology at these sites. We found that despite continuous year-to-year episodes of annual freezing, these estuarine deltas are populated by a range of invertebrates that represent both marine and freshwater assemblages. Freshwater organisms like Diptera and Oligochaeta not only survive this extreme event, but a marine invasion of infaunal organisms such as Amphipoda and Polychaeta rapidly recolonizes the delta mudflats following ice ablation. These delta sediments of sand, silt, and clay are fine in structure compared to sediments of other Beaufort Sea coastal intertidal habitats. The relatively depauperate invertebrate community that ultimately develops is composed of marine and freshwater benthic invertebrates. The composition of the infauna also reflects two strategies that make life on Beaufort Sea deltas possible: a migration of marine organisms from deeper lagoons to the intertidal and freshwater biota that survive the 9-month ice-covered period in frozen sediments. Stable isotopic analyses reveal that both infaunal assemblages assimilate marine and terrestrial sources of organic carbon. These results provide some of the first quantitative information on the infaunal food resources of shallow arctic estuarine systems and the long-term persistence of these invertebrate assemblages. Our data help explain the presence of large numbers of shorebirds in these habitats during the brief summer open-water period and their trophic importance to migrating

  15. 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...

  16. Human Stressors Are Driving Coastal Benthic Long-Lived Sessile Fan Mussel Pinna nobilis Population Structure More than Environmental Stressors.

    Directory of Open Access Journals (Sweden)

    Salud Deudero

    Full Text Available Coastal degradation and habitat disruption are severely compromising sessile marine species. The fan shell Pinna nobilis is an endemic, vulnerable species and the largest bivalve in the Mediterranean basin. In spite of species legal protection, fan shell populations are declining. Models analyzed the contributions of environmental (mean depth, wave height, maximum wave height, period of waves with high energy and mean direction of wave source versus human-derived stressors (anchoring, protection status, sewage effluents, fishing activity and diving as explanatory variables depicting Pinna nobilis populations at a mesoscale level. Human stressors were explaining most of the variability in density spatial distribution of fan shell, significantly disturbing benthic communities. Habitat protection affected P. nobilis structure and physical aggression by anchoring reveals a high impact on densities. Environmental variables instead played a secondary role, indicating that global change processes are not so relevant in coastal benthic communities as human-derived impacts.

  17. Human Stressors Are Driving Coastal Benthic Long-Lived Sessile Fan Mussel Pinna nobilis Population Structure More than Environmental Stressors.

    Science.gov (United States)

    Deudero, Salud; Vázquez-Luis, Maite; Álvarez, Elvira

    2015-01-01

    Coastal degradation and habitat disruption are severely compromising sessile marine species. The fan shell Pinna nobilis is an endemic, vulnerable species and the largest bivalve in the Mediterranean basin. In spite of species legal protection, fan shell populations are declining. Models analyzed the contributions of environmental (mean depth, wave height, maximum wave height, period of waves with high energy and mean direction of wave source) versus human-derived stressors (anchoring, protection status, sewage effluents, fishing activity and diving) as explanatory variables depicting Pinna nobilis populations at a mesoscale level. Human stressors were explaining most of the variability in density spatial distribution of fan shell, significantly disturbing benthic communities. Habitat protection affected P. nobilis structure and physical aggression by anchoring reveals a high impact on densities. Environmental variables instead played a secondary role, indicating that global change processes are not so relevant in coastal benthic communities as human-derived impacts.

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

    International Nuclear Information System (INIS)

    Souza, María Sol; Hallgren, Per; Balseiro, Esteban; Hansson, Lars-Anders

    2013-01-01

    Contraceptive drugs are nowadays found in aquatic environments around the globe. Particularly, 17α-ethinylestradiol (EE 2 ) may act even at low concentrations, such as those recorded in natural ecosystems. We evaluated the physiological effects of EE 2 on cyclopoids and calanoids, common copepods in both marine and freshwater communities. We used three EE 2 concentrations and assessed its impact on activity of different physiological endpoints: Acetylcholinesterase (neurotransmission), Glutathione S-transferase (detoxifying system), and Caspase-3 (apoptosis). While EE 2 exerts, distinctive effect on detoxifying and apoptotic systems, no effect on AChE was observed at environmental doses. Our results show that EE 2 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 (EE 2 ) on copepods. •We measured the EE 2 effect on neurotransmission, detoxifying system and apoptosis. •EE 2 exert distinctive effect on detoxifying and apoptotic systems. •EE 2 affects differently calanoids and cyclopoids moulting and adult recruitment. •Physiological impact in invertebrates' communities is a novel aspect of EE 2 effects. -- Anthropogenic estrogens modify the physiological functioning of aquatic invertebrates

  19. Bottom trawling and oxygen minimum zone influences on continental slope benthic community structure off Vancouver Island (NE Pacific)

    Science.gov (United States)

    De Leo, Fabio C.; Gauthier, Maéva; Nephin, Jessica; Mihály, Steven; Juniper, S. Kim

    2017-03-01

    Understanding responses of benthic ecosystems to cumulative impacts of natural stressors, long-term ocean change and increasing resource exploitation is an emerging area of interest for marine ecologists and environmental managers. Few, if any, studies have quantitatively addressed cumulative effects in the deep sea. We report here on a study from the continental slope off Vancouver Island (Canada) in the northeast Pacific Ocean, where the Oxygen Minimum Zone impinges on seabed habitats that are subjected to widespread bottom trawling, primarily by the fishery for thornyhead (Sebastolobus ssp.). We examined how the benthic megafauna in this area was influenced by varying levels of dissolved oxygen and trawling activity, along a depth gradient that was also likely to shape community composition. Continuous video and sonar records from two ROV surveys (50 linear km total; depth range 300-1400 m) respectively provided data on faunal attributes (composition, abundance and diversity) and the frequency of trawl door marks on the seabed. Faunal and trawl data were compiled in a geo-referenced database along with corresponding dissolved oxygen data, and pooled into 500 m segments for statistical analysis. Trawl mark occurrence peaked between 500 and 1100 m, corresponding to areas of slope subjected to hypoxia (PERMANOVA analyses, with characterizing taxa identified for all three factors. Depth, dissolved oxygen and trawl mark density accounted for 21% to 52% of the variability in benthic community structure according to multiple regression (DISTLM) models. Species richness was highest at intermediate depths and in areas subject to intermediate levels of trawling, and higher under hypoxia than under severe hypoxia. These statistically significant trends demonstrate that the structuring influences of bottom trawling on deep-sea benthic communities can be observed even where communities are being shaped by strong environmental gradients.

  20. Zoology: Invertebrates that Parasitize Invertebrates.

    Science.gov (United States)

    Giribet, Gonzalo

    2016-07-11

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

  1. 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

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

    Science.gov (United States)

    Chimetto Tonon, Luciane A; Silva, Bruno Sergio de O; Moreira, Ana Paula B; Valle, Cecilia; Alves, Nelson; Cavalcanti, Giselle; Garcia, Gizele; Lopes, Rubens M; Francini-Filho, Ronaldo B; de Moura, Rodrigo L; Thompson, Cristiane C; Thompson, Fabiano L

    2015-01-01

    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 seawater and

  3. Metabarcoding monitoring analysis: the pros and cons of using co-extracted environmental DNA and RNA data to assess offshore oil production impacts on benthic communities

    KAUST Repository

    Laroche, Olivier; Wood, Susanna A.; Tremblay, Louis A.; Lear, Gavin; Ellis, Joanne; Pochon, Xavier

    2017-01-01

    benthic communities collected at increasing distances along a transect from an oil production platform (Taranaki, New Zealand). Macro-infauna (visual classification of benthic invertebrates) and physico-chemical data were analyzed in parallel. We tested

  4. An Integrated Approach to Understand Relationships Between Shallow Water Benthic Community Structure and Ecosystem Function

    Science.gov (United States)

    2008-11-01

    REFERENCES Aarnio, K., E. Bonsdorff, and N. Rosenback. 1996. Food and feeding habits of juvenile flounder Platichthys flesus (L.), and turbot...physiological and ecological characteristics of higher taxa, such that crustaceans (especially amphipods and harpacticoid copepods) and echinoderms are...control on benthic processes by feeding on primary producers, bacteria, and detritus. They also serve as major sources of food for higher trophic

  5. Invertebrates in the Classroom.

    Science.gov (United States)

    Abramson, Charles I.

    1986-01-01

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

  6. 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.

  7. 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 moderate-depth...

  8. Benthic foraminifera

    Digital Repository Service at National Institute of Oceanography (India)

    Saraswat, R.; Nigam, R.

    (Nolet and Corliss, 1990). Differences in the abundance of oxygen-sensitive and dissolution-prone benthic foraminiferal species between the Last Glacial Maximum (LGM) and the Holocene in the abyssal waters of the southwestern Gulf of Mexico were used... (2009) Deep-sea benthic diversity linked to seasonality of pelagic productivity. Deep Sea Research Part I: Oceanographic Research Papers 56: 835-841. Culver S (1988) New foraminiferal depth zonation of the northwestern Gulf of Mexico. Palaios 3: 69...

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

    International Nuclear Information System (INIS)

    Amiard-Triquet, Claude.

    1975-11-01

    Exchanges between sediment and marine organisms were studied in some benthic marine invertebrates, especially Arenicola marina L. (an Annelid). Experiments were carried out on the transfer of 60 Co, 137 Cs and accessorily 59 Fe and 144 Ce. Water was the chief vector for benthic marine invertebrates. These invertebrates seemed to act mainly in sedimentary areas on the redistribution of adsorbed radionuclides within the sediment. Radioactive contamination of the invertebrates was affected by various physiological or ecological factors. Benthic marine invertebrates were then studied as links in food chains. The transfer of 60 Co was studied in three food chains or fractions of food chains. The procedure allowed interesting observations from the health protection point of view and more fundamental investigations on cobalt metabolism (regulation, excretion) in a mollusc, a crustacea and a teleost [fr

  10. Effects of sulphur pollution on forest floor invertebrates (community structure, structural heterogeneity, edge effects, decomposition, Callioplus euoplus, Pterostichus adstrictus, Scaphinotus marginatus)

    International Nuclear Information System (INIS)

    Carcamo, H. A.

    1997-01-01

    The distribution of insects and other invertebrates was studied in forests under varying regimes of exposure to sulfur compounds in the vicinity of two sour gas plants and at sharp acidification gradients in pine and aspen forests located near a sulfur block. Results showed no effect on most invertebrates at moderate levels of sulfur deposition. At this level, structural heterogeneity of the forest floor was more influential than sulfur levels in determining the macroarthropoid community structure. By contrast, high sulphur contamination and subsequent acidification had a clear negative effect on earthworms, and various species of spiders. Ground beetles and certain epigeic spiders along the sharp acidification gradient at the pine forest were considered vulnerable but resistant and favoured. These results suggested that ecological specialists were most vulnerable to acidification effects, while ecological generalists have been more successful in resisting the effects of acidification. It was also shown that indirect effects at the landscape, habitat or forest type, and microhabitat level, were more important in the case of most of the arthropods than the direct effects. Only earthworms, snails and some Collembola were negatively affected through direct acidity effects

  11. Effects of sulphur pollution on forest floor invertebrates (community structure, structural heterogeneity, edge effects, decomposition, Callioplus euoplus, Pterostichus adstrictus, Scaphinotus marginatus)

    Energy Technology Data Exchange (ETDEWEB)

    Carcamo, H. A.

    1997-12-31

    The distribution of insects and other invertebrates was studied in forests under varying regimes of exposure to sulfur compounds in the vicinity of two sour gas plants and at sharp acidification gradients in pine and aspen forests located near a sulfur block. Results showed no effect on most invertebrates at moderate levels of sulfur deposition. At this level, structural heterogeneity of the forest floor was more influential than sulfur levels in determining the macroarthropoid community structure. By contrast, high sulphur contamination and subsequent acidification had a clear negative effect on earthworms, and various species of spiders. Ground beetles and certain epigeic spiders along the sharp acidification gradient at the pine forest were considered vulnerable but resistant and favoured. These results suggested that ecological specialists were most vulnerable to acidification effects, while ecological generalists have been more successful in resisting the effects of acidification. It was also shown that indirect effects at the landscape, habitat or forest type, and microhabitat level, were more important in the case of most of the arthropods than the direct effects. Only earthworms, snails and some Collembola were negatively affected through direct acidity effects.

  12. Distribution of metals during digestion by cutthroat trout fed benthic invertebrates contaminated in the Clark Fork River, Montana and the Coeur d'Alene River, Idaho, U.S.A., and fed artificially contaminated Artemia

    Science.gov (United States)

    Farag, A.M.; Suedkamp, M.J.; Meyer, J.S.; Barrows, R.; Woodward, D.F.

    2000-01-01

    The concentrations of essential amino acids in three, undigested invertebrate diets collected from the Clark Fork River (CFR) for cutthroat trout were similar to each other, but were c. 25–75% less than Artemia that were exposed to a mixture of arsenic, copper, cadmium, lead and zinc in the laboratory. The Artemia diet appeared less palatable and the texture, quantity and appearance of the intestinal contents differed between fish fed the Artemia and CFR diets. The Pb% in the fluid fraction of the intestinal contents was greater for the Artemia (29%) than for the CFR diets (10–17%), and the Cu% in the amino acid plus metal fraction of the intestinal contents was greater for the Artemia (78%) than for two of the three CFR diets (67% and 70%). Intestinal contents of fish fed invertebrate diets collected from various sites on the Coeur d'Alene River (CDA), Idaho, were similar in texture, quantity, and appearance. For fish fed the CDA diets, differences in the distribution of metals among fractions of the digestive fluids appeared to be related to concentrations of metals in the invertebrate diets. Pb% was lowest of all metals in the fluid portion of the intestinal contents. However, >80% of all metals in the hind gut were associated with the particulate fraction where they may still be available for uptake through pinocytosis.

  13. Internal tides affect benthic community structure in an energetic submarine canyon off SW Taiwan

    Science.gov (United States)

    Liao, Jian-Xiang; Chen, Guan-Ming; Chiou, Ming-Da; Jan, Sen; Wei, Chih-Lin

    2017-07-01

    Submarine canyons are major conduits of terrestrial and shelf organic matter, potentially benefiting the seafloor communities in the food-deprived deep sea; however, strong bottom currents driven by internal tides and the potentially frequent turbidity currents triggered by storm surges, river flooding, and earthquakes may negatively impact the benthos. In this study, we investigated the upper Gaoping Submarine Canyon (GPSC), a high-sediment-yield canyon connected to a small mountain river (SMR) off southwest (SW) Taiwan. By contrasting the benthic meiofaunal and macrofaunal communities within and outside the GPSC, we examined how food supplies and disturbance influenced the benthic community assemblages. The benthic communities in the upper GPSC were mainly a nested subset of the adjacent slope assemblages. Several meiofaunal (e.g. ostracods) and macrofaunal taxa (e.g. peracarid crustaceans and mollusks) that typically occurred on the slope were lost from the canyon. The polychaete families switched from diverse feeding guilds on the slope to motile subsurface deposit feeders dominant in the canyon. The diminishing of epibenthic peracarids and proliferation of deep burrowing polychaetes in the GPSC resulted in macrofauna occurring largely within deeper sediment horizons in the canyon than on the slope. The densities and numbers of taxa were depressed with distinct and more variable composition in the canyon than on the adjacent slope. Both the densities and numbers of taxa were negatively influenced by internal tide flushing and positively influenced by food availability; however, the internal tides also negatively influenced the food supplies. While the meiofauna and macrofauna densities were both depressed by the extreme physical conditions in the GPSC, only the macrofaunal densities increased with depth in the canyon, presumably related to increased frequency and intensity of disturbance toward the canyon head. The population densities of meiofauna, on the

  14. BENTHIC MACROINVERTEBRATE COMMUNITY STRUCTURE IN THE UPPER HYDROGRAPHIC BASIN OF CERNA RIVER IN RELATION TO WATER QUALITY (WEST AND SOUTH-WESTERN ROMANIA

    Directory of Open Access Journals (Sweden)

    CORINA TUDORESCU

    2009-01-01

    Full Text Available The quality of an hydrographic basin may be reflected by the composition of benthic macroinvertebrates communities as they can be influenced by the quality degradations of physical and chemical water parameters. The structure of the benthic community in the upper basin of the Cerna river was characterized by the presence of 13 groups. Abundance and frequency values recorded for benthic communities varied according to the physical-chemical conditions specific to each sample collecting station. Plecoptera, Ephemeroptera, Trichoptera and Amphipoda were influenced by changes in water quality, changes that were reflected in the composition and structure of such communities with low levels of abundance, reaching extinction in some areas of the basin.

  15. Layered Growth and Crystallization in Calcareous Biominerals: Impact of Structural and Chemical Evidence on Two Major Concepts in Invertebrate Biomineralization Studies

    Directory of Open Access Journals (Sweden)

    Jean-Pierre Cuif

    2012-02-01

    Full Text Available In several recent models of invertebrate skeletogenesis, Ca-carbonate crystallization occurs within a liquid-filled chamber. No explanation is given neither for the simultaneous occurrence of distinct polymorphs of Ca-carbonate within these liquid volumes, nor for the spatial arrangement of the mineral units which are always organized in species-specific structural sequences. Results of a series of physical characterizations applied to reference skeletal materials reveal the inadequacy of this liquid-filled chamber model to account for structural and chemical properties of the shell building units. Simultaneously, these data provide convergent pieces of evidence for a specific mode of crystallization developed throughout various invertebrate phyla, supporting the hypothesized “common strategy” based on a multi-scaled control exerted on formation of their calcareous hard parts.

  16. 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.

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

    International Nuclear Information System (INIS)

    Juárez-de la Rosa, B.A.; May-Crespo, J.; Quintana-Owen, P.; Gónzalez-Gómez, W.S.; Yañez-Limón, J.M.; Alvarado-Gil, J.J.

    2015-01-01

    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. 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

  19. 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.

  20. Influence of Benthic Macrofauna as a Spatial Structuring Agent for Juvenile Haddock (Melanogrammus aeglefinus) on the Eastern Scotian Shelf, Atlantic Canada.

    Science.gov (United States)

    Rincón, Beatriz; Kenchington, Ellen L

    2016-01-01

    We examined the habitat of juvenile haddock on the eastern Scotian Shelf (off Nova Scotia, Canada) in relation to grab-sampled benthic macrofaunal invertebrate species assemblages in order to determine whether there were significant differences in benthic macrofauna between areas of historically persistent high and low juvenile haddock abundance. Our analyses were conducted over two spatial scales in each of two years: among banks (Emerald, Western and Sable Island), approximately 60 km distant from each other, and between areas of high and low juvenile haddock abundance at distances of 10 to 30 km-all in an area that had not experienced groundfishing in the decade prior to sampling. We also examined fine-scale (10s of metres) within-site variability in the macrofauna and used surficial sediment characteristics, along with hydrographic variables, to identify environmental correlates. PERMANOVA identified statistically significant differences in biomass, density and composition of the benthos associated with juvenile haddock abundance; however it was difficult to determine whether the results had biological relevance. Post hoc tests showed that these differences occurred only on Sable Island Bank where both fish and benthos may have been independently responding to sediment type which was most different there (100% sand in the area of low haddock abundance vs. 22% gravel in the area of high haddock abundance). In total, 383 benthic taxa representing 13 phyla were identified. Annelida was the most specious phylum (36.29% of taxa, representing 33 families), followed by Arthropoda (with Crustaceans, mostly Amphipoda, accounting for 25.07% of the total number of taxa). The strongest pattern in the macrofauna was expressed at the largest scale, between banks, accounting for approximately 25% of the variation in the data. Emerald Bank, deeper, warmer and saltier than the Western and Sable Island Banks, had a distinctive fauna.

  1. Influence of Benthic Macrofauna as a Spatial Structuring Agent for Juvenile Haddock (Melanogrammus aeglefinus) on the Eastern Scotian Shelf, Atlantic Canada

    Science.gov (United States)

    2016-01-01

    We examined the habitat of juvenile haddock on the eastern Scotian Shelf (off Nova Scotia, Canada) in relation to grab-sampled benthic macrofaunal invertebrate species assemblages in order to determine whether there were significant differences in benthic macrofauna between areas of historically persistent high and low juvenile haddock abundance. Our analyses were conducted over two spatial scales in each of two years: among banks (Emerald, Western and Sable Island), approximately 60 km distant from each other, and between areas of high and low juvenile haddock abundance at distances of 10 to 30 km–all in an area that had not experienced groundfishing in the decade prior to sampling. We also examined fine-scale (10s of metres) within-site variability in the macrofauna and used surficial sediment characteristics, along with hydrographic variables, to identify environmental correlates. PERMANOVA identified statistically significant differences in biomass, density and composition of the benthos associated with juvenile haddock abundance; however it was difficult to determine whether the results had biological relevance. Post hoc tests showed that these differences occurred only on Sable Island Bank where both fish and benthos may have been independently responding to sediment type which was most different there (100% sand in the area of low haddock abundance vs. 22% gravel in the area of high haddock abundance). In total, 383 benthic taxa representing 13 phyla were identified. Annelida was the most specious phylum (36.29% of taxa, representing 33 families), followed by Arthropoda (with Crustaceans, mostly Amphipoda, accounting for 25.07% of the total number of taxa). The strongest pattern in the macrofauna was expressed at the largest scale, between banks, accounting for approximately 25% of the variation in the data. Emerald Bank, deeper, warmer and saltier than the Western and Sable Island Banks, had a distinctive fauna. PMID:27649419

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

    DEFF Research Database (Denmark)

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

    2015-01-01

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

  3. National Coral Reef Monitoring Program: Assessing and Monitoring Cryptic Reef Diversity of Colonizing Marine Invertebrates using Autonomous Reef Monitoring Structure (ARMS) Deployed at Coral Reef Sites across the Pacific Remote Island Areas from 2011 to 2015

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — Autonomous Reef Monitoring Structures (ARMS) are used to assess and monitor cryptic reef diversity of colonizing marine invertebrates in the Hawaiian and Mariana...

  4. National Coral Reef Monitoring Program: Assessing and Monitoring Cryptic Reef Diversity of Colonizing Marine Invertebrates using Autonomous Reef Monitoring Structure (ARMS) Deployed at Coral Reef Sites across the Marianas Archipelago from 2011 to 2014

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — Autonomous Reef Monitoring Structures (ARMS) are used to assess and monitor cryptic reef diversity of colonizing marine invertebrates in the Hawaiian and Mariana...

  5. National Coral Reef Monitoring Program: Assessing and Monitoring Cryptic Reef Diversity of Colonizing Marine Invertebrates using Autonomous Reef Monitoring Structure (ARMS) Deployed at Coral Reef Sites across the Hawaiian Archipelago from 2010 to 2016

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — Autonomous Reef Monitoring Structures (ARMS) are used to assess and monitor cryptic reef diversity of colonizing marine invertebrates in the Hawaiian and Mariana...

  6. National Coral Reef Monitoring Program: Assessing and Monitoring Cryptic Reef Diversity of Colonizing Marine Invertebrates using Autonomous Reef Monitoring Structure (ARMS) Deployed at Coral Reef Sites across American Samoa from 2012 to 2015

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — Autonomous Reef Monitoring Structures (ARMS) are used to assess and monitor cryptic reef diversity of colonizing marine invertebrates in the Hawaiian and Mariana...

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

    Science.gov (United States)

    Pamela E. Porter; William R. Meehan

    1987-01-01

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

  8. The influence of coral reef benthic condition on associated fish assemblages.

    Directory of Open Access Journals (Sweden)

    Karen M Chong-Seng

    Full Text Available Accumulative disturbances can erode a coral reef's resilience, often leading to replacement of scleractinian corals by macroalgae or other non-coral organisms. These degraded reef systems have been mostly described based on changes in the composition of the reef benthos, and there is little understanding of how such changes are influenced by, and in turn influence, other components of the reef ecosystem. This study investigated the spatial variation in benthic communities on fringing reefs around the inner Seychelles islands. Specifically, relationships between benthic composition and the underlying substrata, as well as the associated fish assemblages were assessed. High variability in benthic composition was found among reefs, with a gradient from high coral cover (up to 58% and high structural complexity to high macroalgae cover (up to 95% and low structural complexity at the extremes. This gradient was associated with declining species richness of fishes, reduced diversity of fish functional groups, and lower abundance of corallivorous fishes. There were no reciprocal increases in herbivorous fish abundances, and relationships with other fish functional groups and total fish abundance were weak. Reefs grouping at the extremes of complex coral habitats or low-complexity macroalgal habitats displayed markedly different fish communities, with only two species of benthic invertebrate feeding fishes in greater abundance in the macroalgal habitat. These results have negative implications for the continuation of many coral reef ecosystem processes and services if more reefs shift to extreme degraded conditions dominated by macroalgae.

  9. Production of marine trematode cercariae: a potentially overlooked path of energy flow in benthic systems

    DEFF Research Database (Denmark)

    Thieltges, David W.; de Montaudouin, Xavier; Fredensborg, Brian

    2008-01-01

    Parasites, in particular trematodes, are unseen but ubiquitous components of marine intertidal ecosystems. Although parasites are known to affect population dynamics and food web structure, their potential function as an unrecognized path of energy flow in these ecosystems is yet to be quantified...... in different marine benthic systems. Across 18 trematode species, cercarial output (no. cercariae shed snail-1 d-1) ranged over 4 orders of magnitude and was positively correlated with snail host species size. While cercarial output did not correlate with latitude, it did correlate negatively with the size...... reported for free-living invertebrates inhabiting benthic ecosystems. These estimates would be much higher if they included all trematode species in an ecosystem, and not just single-species values. Overall, results suggest that trematode cercariae represent potentially important paths of energy flow...

  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. 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

  12. The relation between Acid Volatile Sulfides (AVS) and metal accumulation in aquatic invertebrates: implications of feeding behavior and ecology.

    Science.gov (United States)

    De Jonge, Maarten; Blust, Ronny; Bervoets, Lieven

    2010-05-01

    The present study evaluates the relationship between Acid Volatile Sulfides (AVS) and metal accumulation in invertebrates with different feeding behavior and ecological preferences. Natural sediments, pore water and surface water, together with benthic and epibenthic invertebrates were sampled at 28 Flemish lowland rivers. Different metals as well as metal binding sediment characteristics including AVS were measured and multiple regression was used to study their relationship with accumulated metals in the invertebrates taxa. Bioaccumulation in the benthic taxa was primarily influenced by total metal concentrations in the sediment. Regarding the epibenthic taxa metal accumulation was mostly explained by the more bioavailable metal fractions in both the sediment and the water. AVS concentrations were generally better correlated with metal accumulation in the epibenthic invertebrates, rather than with the benthic taxa. Our results indicated that the relation between AVS and metal accumulation in aquatic invertebrates is highly dependent on feeding behavior and ecology. Copyright 2010 Elsevier Ltd. All rights reserved.

  13. The effects of top-down versus bottom-up control on benthic coral reef community structure.

    Science.gov (United States)

    Smith, Jennifer E; Hunter, Cynthia L; Smith, Celia M

    2010-06-01

    While climate change and associated increases in sea surface temperature and ocean acidification, are among the most important global stressors to coral reefs, overfishing and nutrient pollution are among the most significant local threats. Here we examined the independent and interactive effects of reduced grazing pressure and nutrient enrichment using settlement tiles on a coral-dominated reef via long-term manipulative experimentation. We found that unique assemblages developed in each treatment combination confirming that both nutrients and herbivores are important drivers of reef community structure. When herbivores were removed, fleshy algae dominated, while crustose coralline algae (CCA) and coral were more abundant when herbivores were present. The effects of fertilization varied depending on herbivore treatment; without herbivores fleshy algae increased in abundance and with herbivores, CCA increased. Coral recruits only persisted in treatments exposed to grazers. Herbivore removal resulted in rapid changes in community structure while there was a lag in response to fertilization. Lastly, re-exposure of communities to natural herbivore populations caused reversals in benthic community trajectories but the effects of fertilization remained for at least 2 months. These results suggest that increasing herbivore populations on degraded reefs may be an effective strategy for restoring ecosystem structure and function and in reversing coral-algal phase-shifts but that this strategy may be most effective in the absence of other confounding disturbances such as nutrient pollution.

  14. Eutrophication induced changes in benthic community structure of a flow-restricted tropical estuary (Cochin backwaters), India

    Digital Repository Service at National Institute of Oceanography (India)

    Martin, G.D.; Nisha, P.A.; Balachandran, K.K.; Madhu, N.V.; Nair, M.; Shaiju, P.; Joseph, T.; Srinivas, K.; Gupta, G.V.M.

    The influence of anthropogenic loading on the distribution of soft bottom benthic organisms of a tropical estuary (Cochin backwaters) was examined. The industrial activities were found to be high in the northern and central part of the estuary...

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

    Science.gov (United States)

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

    2017-12-01

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

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

    Science.gov (United States)

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

    2015-05-01

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

  17. Establishing the solubility and local structure(s) of Amorphous Calcium Carbonate (ACC): Toward an understanding of invertebrate biomineralization

    Science.gov (United States)

    Mergelsberg, S. T.; Ulrich, R. N.; Michel, F. M.; Dove, P. M.

    2017-12-01

    Recent advances in high-resolution imaging show the widespreadd occurrence of multistep pathways to mineralization in biological and geological settings (De Yoreo et al., 2015, Science). For example, carbonate biomineralization often involves precipitation of amorphous calcium carbonate (ACC) as a reactive intermediate that subsequently transforms to crystalline products with diverse structures. Although current carbonate mineral proxies are based upon the composition of final crystalline products, the final signatures may be recording the properties of the initial amorphous phase. Thus, it is critical to establish the physical properties of ACC and understand the factors that influence its evolution to final products at conditions that approximate biological environments. This disconnect limits our ability to build a process-based understanding of when/how minor and trace elements are recorded in mineral composition proxies. In this experimental study, we quantified the chemical and physical properties of ACC and its evolution to final products. We first determined ACC solubility under controlled chemical conditions using a new type of flow-through reactor developed by our research group (Blue and Dove, 2015, GCA; Blue et al., 2017, GCA). The experimental design varied Mg concentration and total alkalinity while maintaining a mild pH that approximates biological environments. ACC solubility was measured at specific time points during the precipitation (from super- and undersaturated conditions) and during its subsequent evolution. Parallel experiments characterized the structure of the corresponding amorphous products using in situ pair distribution function (PDF) and small-angle x-ray scattering (SAXS) analyses. The measurements demonstrate at least two types of ACC can be produced by tuning Mg concentration and alkalinity. Each "phase" exhibits distinct short-range ordering that demonstrates structure-specific solubility. We also find temporal changes in the

  18. Fertilization of Earth Ponds. III: Effects on Benthic Macro ...

    African Journals Online (AJOL)

    Organic fertilizers in form of cow and chicken manure were applied in oligotrophic or unproductive pond water over a period of one year to stimulate the production of benthic macro invertebrates for the benefit of trout culture, while maintaining adequate water quality. Development of aquatic macrophytes during both ...

  19. Larval transport modeling of deep-sea invertebrates can aid the search for undiscovered populations.

    Directory of Open Access Journals (Sweden)

    Jon M Yearsley

    Full Text Available BACKGROUND: Many deep-sea benthic animals occur in patchy distributions separated by thousands of kilometres, yet because deep-sea habitats are remote, little is known about their larval dispersal. Our novel method simulates dispersal by combining data from the Argo array of autonomous oceanographic probes, deep-sea ecological surveys, and comparative invertebrate physiology. The predicted particle tracks allow quantitative, testable predictions about the dispersal of benthic invertebrate larvae in the south-west Pacific. PRINCIPAL FINDINGS: In a test case presented here, using non-feeding, non-swimming (lecithotrophic trochophore larvae of polyplacophoran molluscs (chitons, we show that the likely dispersal pathways in a single generation are significantly shorter than the distances between the three known population centres in our study region. The large-scale density of chiton populations throughout our study region is potentially much greater than present survey data suggest, with intermediate 'stepping stone' populations yet to be discovered. CONCLUSIONS/SIGNIFICANCE: We present a new method that is broadly applicable to studies of the dispersal of deep-sea organisms. This test case demonstrates the power and potential applications of our new method, in generating quantitative, testable hypotheses at multiple levels to solve the mismatch between observed and expected distributions: probabilistic predictions of locations of intermediate populations, potential alternative dispersal mechanisms, and expected population genetic structure. The global Argo data have never previously been used to address benthic biology, and our method can be applied to any non-swimming larvae of the deep-sea, giving information upon dispersal corridors and population densities in habitats that remain intrinsically difficult to assess.

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

    NARCIS (Netherlands)

    Sokolowski, A.; Wolowicz, M.; Asmus, H.; Asmus, R.; Carlier, A.; Gasiunaite, Z.; Gremare, A.; Hummel, H.; Lesutiene, J.; Razinkovas, A.; Renaud, P.E.; Richard, P.; Kedra, M.

    2012-01-01

    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.

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

    African Journals Online (AJOL)

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

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

    Science.gov (United States)

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

    2016-06-01

    For the first time in the current literature, the effect of titanium dioxide (TiO2) nanoparticles on the community structure of macroinvertebrates has been investigated in situ. Macroinvertebrates were exposed for 100 days to an environmentally relevant concentration of TiO2 nanoparticles, 25 mg kg(-1) in sediment. Czekanowski's index was 0.61, meaning 39% of the macroinvertebrate community structure was affected by the TiO2 treatment. Non-metric multidimensional scaling (NMDS) visualized the qualitative and quantitative variability of macroinvertebrates at the community level among all samples. A distance-based permutational multivariate analysis of variance (PERMANOVA) revealed the significant effect of TiO2 on the macroinvertebrate community structure. The indicator value analysis showed that the relative frequency and abundance of Planorbarius corneus and Radix labiata were significantly lower in the TiO2 treatment than in the control. Meanwhile, Ceratopogonidae, showed a significantly higher relative frequency and abundance in the TiO2 treatment than in the control. Copyright © 2016 Elsevier Ltd. All rights reserved.

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

    Science.gov (United States)

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

    2011-08-30

    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 CO(2) 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 (ambient, low, and extreme low), which differed in both the mean and variability of seawater pH along a continuous gradient. We found fewer taxa, reduced taxonomic evenness, and lower biomass in the extreme low pH zones. However, the number of individuals did not differ among pH zones, suggesting that there is density compensation through population blooms of small acidification-tolerant taxa. Furthermore, the trophic structure of the invertebrate community shifted to fewer trophic groups and dominance by generalists in extreme low pH, suggesting that there may be a simplification of food webs with ocean acidification. Despite high variation in individual species' responses, our findings indicate that ocean acidification decreases the diversity, biomass, and trophic complexity of benthic marine communities. These results suggest that a loss of biodiversity and ecosystem function is expected under extreme acidification scenarios.

  4. Benthic megafaunal community structure of cobalt-rich manganese crusts on Necker Ridge

    Science.gov (United States)

    Morgan, Nicole B.; Cairns, Stephen; Reiswig, Henry; Baco, Amy R.

    2015-10-01

    In the North Pacific Ocean, the seamounts of the Hawaiian Archipelago and the Mid-Pacific Mountains are connected by Necker Ridge, a 600 km-long feature spanning a depth range of 1400-4000 m. The Necker Ridge is a part of a large area of the central and western Pacific under consideration for cobalt-rich manganese crust mining. We describe the fauna and community structure of the previously unsampled Necker Ridge based on explorations with the submersible Pisces IV. On five pinnacles and a portion of the Ridge ranging from 1400 to 2000 m deep, 27 transects were recorded using HD video, and voucher specimens were collected to aid in species identification. The video was analyzed to identify and count the megafauna found on each transect and to characterize the substrate. Diversity increased from south to north along the feature. There was a significant difference in community structure between southern and northern pinnacles, with southern pinnacles dominated by crinoids of the Family Charitometridae and northern pinnacles dominated by octocorals, especially the Families Isididae and Chrysogorgiidae. DistLM demonstrated a correlation between community structure on the pinnacles and at least six environmental variables, including latitude, sediment cover, and oxygen concentration, but not including depth. The discontinuous and patchy nature of these distinct megafaunal communities highlights growing evidence that cobalt-rich seamounts are highly heterogeneous habitats, and that managing seamounts may require more complex regulations than treating them as a single ecological unit. These results suggest that extensive community analysis should occur at a given site to determine management priority areas, prior to consideration of that site for exploitation of natural resources.

  5. 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

  6. Uniform functional structure across spatial scales in an intertidal benthic assemblage.

    Science.gov (United States)

    Barnes, R S K; Hamylton, Sarah

    2015-05-01

    To investigate the causes of the remarkable similarity of emergent assemblage properties that has been demonstrated across disparate intertidal seagrass sites and assemblages, this study examined whether their emergent functional-group metrics are scale related by testing the null hypothesis that functional diversity and the suite of dominant functional groups in seagrass-associated macrofauna are robust structural features of such assemblages and do not vary spatially across nested scales within a 0.4 ha area. This was carried out via a lattice of 64 spatially referenced stations. Although densities of individual components were patchily dispersed across the locality, rank orders of importance of the 14 functional groups present, their overall functional diversity and evenness, and the proportions of the total individuals contained within each showed, in contrast, statistically significant spatial uniformity, even at areal scales functional groups in their geospatial context also revealed weaker than expected levels of spatial autocorrelation, and then only at the smaller scales and amongst the most dominant groups, and only a small number of negative correlations occurred between the proportional importances of the individual groups. In effect, such patterning was a surface veneer overlying remarkable stability of assemblage functional composition across all spatial scales. Although assemblage species composition is known to be homogeneous in some soft-sediment marine systems over equivalent scales, this combination of patchy individual components yet basically constant functional-group structure seems as yet unreported. Copyright © 2015 Elsevier Ltd. All rights reserved.

  7. Sediment pollution and predation affect structure and production of benthic macroinvertebrate communities in the Rhine-Meuse delta, The Netherlands

    NARCIS (Netherlands)

    Lange, de H.J.; Jonge, de J.; Besten, den P.J.; Oosterbaan, J.; Peeters, E.T.H.M.

    2004-01-01

    Most floodplain sediments of the rivers Rhine and Meuse in The Netherlands are moderately polluted with trace metals, polycyclic aromatic hydrocarbons (PAHs), polychlorinated biphenyls (PCBs), and other chemicals. The effects of these sediment-bound contaminants on the productivity of benthic

  8. 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

    Cenomanian chalk-marl couplets from England represent the 20 ka Milankovitch precession cycle. Fossil communities from both chalk and marl are identified to test if the orbital fluctuations and the associated changes in substrate lithology and climate exerted any control on the benthic macrofauna...

  9. The potential role of habitat-forming seaweeds in modeling benthic ecosystem properties

    Science.gov (United States)

    Bustamante, María; Tajadura, Javier; Díez, Isabel; Saiz-Salinas, José Ignacio

    2017-12-01

    Canopy-forming seaweeds provide specific habitats with key ecological properties and are facing severe declines worldwide with unforeseeable consequences for ecosystem processes. Investigating the loss of such natural habitats in order to develop management strategies for conservation is a major challenge in marine ecological research. This study investigated the shallow rocky bottoms of the southern Bay of Biscay at two sampling times with a view to identifying the effect of canopy seaweed availability on the taxonomic and functional properties of invertebrate multivariate structure, abundance, density, diversity and evenness. The multivariate taxonomic and functional structure of assemblages changed significantly according to canopy availability in terms of taxa and functional groups abundance, but no substantial change was observed in composition. Biogenic habitat simplification resulted in a decrease in total invertebrate abundance and in taxonomic and functional density and diversity, whilst no effects were observed in taxonomic and functional evenness. Loss of canopy involved an impoverishment of the whole community particularly for epiphytic colonial sessile suspension-feeders, but it also extended to non-epiphytic forms. Our results emphasize the importance of canopy decline as a major driver of changes in benthic ecosystem properties and highlight that biogenic space provided by canopy is a limiting resource for the development of rocky subtidal invertebrates.

  10. Antimycobacterial Metabolites from Marine Invertebrates.

    Science.gov (United States)

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

    2016-10-01

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

  11. Diversity of large DNA viruses of invertebrates.

    Science.gov (United States)

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

    2017-07-01

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

  12. 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.)

  13. Sphagnum mosses as a microhabitat for invertebrates in acidified lakes and the colour adaptation and substrate preference in Leucorrhinia dubia (Odonata, Anisoptera)

    Energy Technology Data Exchange (ETDEWEB)

    Henrikson, B.-I. (Dept. of Zoology, Sect. of Animal Ecology, Univ. of Goeteborg, Goeteborg (Sweden))

    1993-01-01

    The increase of peat mosses, Sphagnum spp., in acidified lakes leads to a changed microhabitat structure for benthic invertebrates. The importance of this change was investigated for some benthic invertebrates. Comparisons between quantitative samples of Sphagnum and debris within the acidified Lake Stora Haestevatten, in the Lake Gaardsjoen catchment of SW Sweden, showed significantly higher abundances of Chironomidae, Ceratopogonidae, Odonata, Trichoptera, Cladocera and Argyroneta aquatica (Araneae) in Sphagnum. For chironomidae and Cladocera the differences were tenfold. Special reference was made to the libellulid Leucorrhinia dubia which is common in acid lakes. In a laboratory test, late instar larvae of L. dubia were shown to change colour to correspond to the brown and green colour of Sphagnum. This result was completed with a field test where larvae of L. dubia were significantly more common in Sphagnum of the same colour as the larvae. The ability to change colour may have an adaptive value when coexisting with visual predators. Small larvae were more prevalent in Sphagnum and they also showed a preference for this substrate in the laboratory test. Laboratory tests showed mediumsized larvae preferred Sphagnum. Larvae of L. dubia were more successful as predators on Asellus aquaticus in Sphagnum substrate than in debris in the laboratory test. Laboratory predation tests with notonecta glauca, Corixa dentipes, Acilius sulcatus, Hyphydrus ovatus and L. dubia showed that they could all feed on larvae of L. dubia. The complex habitat structure of Sphagnum is probably the reason for the high abundance of invertebrates since it may serve as both shelter against predation and as foraging sites. it is probably important as a key habitat for young instars of, for example, L. dubia. In lakes with large Sphagnum mats, L. dubia can coexist with fish. The expansion of Sphagnum due to acidification will probably benefit many acid-tolerant invertebrate species. (au)

  14. The invertebrate communities

    International Nuclear Information System (INIS)

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

    1985-01-01

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

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

    Science.gov (United States)

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

    2015-01-01

    -scale and wide ranging negative biological and ecological impacts on a wide range of non-target invertebrates in terrestrial, aquatic, marine and benthic habitats.

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

    African Journals Online (AJOL)

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

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

    Science.gov (United States)

    1981-01-01

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

  18. 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)

  19. Habitat variation and life history strategies of benthic invertebrates

    NARCIS (Netherlands)

    Franken, R.J.M.

    2008-01-01

    The thesis considers two key aspects of lotic freshwater ecosystems, the physical microhabitat and organic matter dynamics. The first part focuses on the indirect effects of light and riparian canopy cover on shredder growth and productivity through the effect on the nutritional quality of the food

  20. Biokinetics of 237Np in two marine benthic invertebrates

    International Nuclear Information System (INIS)

    Guary, J.C.; Fowler, S.W.

    1976-01-01

    The long-lived alpha-emitting actinide 237 Np (T 1/2 = 2.2 x 10 6 y) enters the aquatic environment directly from nuclear testing and reprocessing plant wastes as well as indirectly by in situ generation from 241 Am. Earlier studies on 239 Np in the Columbia river ecosystem demonstrated that neptunium accumulated in aquatic species such as algae, sponges and insect larvae but was not detectable in higher trophic level organisms. Based on these findings and the fact that neptunium is chemically similar to the rare earth elements, it has been suggested that this actinide would not easily become incorporated into aquatic biota

  1. 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...... to a 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...

  2. 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.

  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

    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. Immune memory in invertebrates.

    Science.gov (United States)

    Milutinović, Barbara; Kurtz, Joachim

    2016-08-01

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

  5. 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...

  6. 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)

    Reish, D.J.

    1983-01-01

    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

  7. 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.

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

    OpenAIRE

    Whitcraft, Christine René

    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...

  9. Antifouling Compounds from Marine Invertebrates.

    Science.gov (United States)

    Qi, Shu-Hua; Ma, Xuan

    2017-08-28

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

  10. Aquarium Culture of Freshwater Invertebrates.

    Science.gov (United States)

    Wood, Timothy S.

    1996-01-01

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

  11. Antifouling Compounds from Marine Invertebrates

    OpenAIRE

    Qi, Shu-Hua; Ma, Xuan

    2017-01-01

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

  12. Hawaii ESI: INVERTPT (Invertebrate Points)

    Data.gov (United States)

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

  13. The Effects of Anthropogenic Structures on Habitat Connectivity and the Potential Spread of Non-Native Invertebrate Species in the Offshore Environment.

    Science.gov (United States)

    Simons, Rachel D; Page, Henry M; Zaleski, Susan; Miller, Robert; Dugan, Jenifer E; Schroeder, Donna M; Doheny, Brandon

    2016-01-01

    Offshore structures provide habitat that could facilitate species range expansions and the introduction of non-native species into new geographic areas. Surveys of assemblages of seven offshore oil and gas platforms in the Santa Barbara Channel revealed a change in distribution of the non-native sessile invertebrate Watersipora subtorquata, a bryozoan with a planktonic larval duration (PLD) of 24 hours or less, from one platform in 2001 to four platforms in 2013. We use a three-dimensional biophysical model to assess whether larval dispersal via currents from harbors to platforms and among platforms is a plausible mechanism to explain the change in distribution of Watersipora and to predict potential spread to other platforms in the future. Hull fouling is another possible mechanism to explain the change in distribution of Watersipora. We find that larval dispersal via currents could account for the increase in distribution of Watersipora from one to four platforms and that Watersipora is unlikely to spread from these four platforms to additional platforms through larval dispersal. Our results also suggest that larvae with PLDs of 24 hours or less released from offshore platforms can attain much greater dispersal distances than larvae with PLDs of 24 hours or less released from nearshore habitat. We hypothesize that the enhanced dispersal distance of larvae released from offshore platforms is driven by a combination of the offshore hydrodynamic environment, larval behavior, and larval release above the seafloor.

  14. Invertebrates and Plants :: NOAA Fisheries

    Science.gov (United States)

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

  15. Benthic community structure and composition in sediment from the northern Gulf of Mexico shoreline, Texas to Florida

    Science.gov (United States)

    Demopoulos, Amanda W.J.; Strom, Douglas G.

    2012-01-01

    From April 20 through July 15, 2010, approximately 4.93 million barrels of crude oil spilled into the Gulf of Mexico from the British Petroleum Macondo-1 well, representing the largest spill in U.S. waters. Baseline benthic community conditions were assessed from shoreline sediment samples collected from 56 stations within the swash zone (for example, sample depth ranged from 0 to 1.5 feet) along the northern Gulf of Mexico coastline. These sites were selected because they had a high probability of being impacted by the oil. Cores collected at 24 stations contained no sediment infauna. Benthic community metrics varied greatly among the remaining stations. Mississippi stations had the highest mean abundances (38.9 ± 23.9 individuals per 32 square centimeters (cm2); range: 0 to 186), while Texas had the lowest abundances, 4.9 ± 3 individuals per 32 cm2 (range: 0 to 25). Dominant phyla included Annelida, Arthropoda, and Mollusca, but proportional contributions of each group varied by State. Diversity indices Margalef's richness (d) and Shannon-Wiener diversity (H') were highest at Louisiana and Mississippi stations (0.4 and 0.4, for both, respectively) and lowest at Texas (values for both indices were 0.1 ± 0.1). Evenness (J') was low for all the States, ranging from 0.2 to 0.3, indicating a high degree of patchiness at these sites. Across stations within a State, average similarity ranged from 11.1 percent (Mississippi) to 41.1 percent (Louisiana). Low within-state similarity may be a consequence of differing habitat and physical environment conditions. Results provide necessary baseline information that will facilitate future comparisons with post-spill community metrics.

  16. Invertebrates and Plants

    Science.gov (United States)

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

    2013-01-01

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

  17. Tube-dwelling invertebrates

    NARCIS (Netherlands)

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

    2015-01-01

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

  18. 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

  19. 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

  20. Lake Ontario benthic prey fish assessment, 2015

    Science.gov (United States)

    Weidel, Brian C.; Walsh, Maureen; Holden, Jeremy P.; Connerton, Michael J.

    2016-01-01

    Benthic prey fishes are a critical component of the Lake Ontario food web, serving as energy vectors from benthic invertebrates to native and introduced piscivores. Since the late 1970’s, Lake Ontario benthic prey fish status was primarily assessed using bottom trawl observations confined to the lake’s south shore, in waters from 8 – 150 m (26 – 492 ft). In 2015, the Benthic Prey Fish Survey was cooperatively adjusted and expanded to address resource management information needs including lake-wide benthic prey fish population dynamics. Effort increased from 55 bottom trawl sites to 135 trawl sites collected in depths from 8 - 225m (26 – 738 ft). The spatial coverage of sampling was also expanded and occurred in all major lake basins. The resulting distribution of tow depths more closely matched the available lake depth distribution. The additional effort illustrated how previous surveys were underestimating lake-wide Deepwater Sculpin, Myoxocephalus thompsonii, abundance by not sampling in areas of highest density. We also found species richness was greater in the new sampling sites relative to the historic sites with 11 new fish species caught in the new sites including juvenile Round Whitefish, Prosopium cylindraceum, and Mottled sculpin, Cottus bairdii. Species-specific assessments found Slimy Sculpin, Cottus cognatus abundance increased slightly in 2015 relative to 2014, while Deepwater Sculpin and Round Goby, Neogobius melanostomus, dramatically increased in 2015, relative to 2014. The cooperative, lake-wide Benthic Prey Fish Survey expanded our understanding of benthic fish population dynamics and habitat use in Lake Ontario. This survey’s data and interpretations influence international resource management decision making, such as informing the Deepwater Sculpin conservation status and assessing the balance between sport fish consumption and prey fish populations. Additionally a significant Lake Ontario event occurred in May 2015 when a single

  1. 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.

  2. The relation between Acid Volatile Sulfides (AVS) and metal accumulation in aquatic invertebrates: Implications of feeding behavior and ecology

    International Nuclear Information System (INIS)

    De Jonge, Maarten; Blust, Ronny; Bervoets, Lieven

    2010-01-01

    The present study evaluates the relationship between Acid Volatile Sulfides (AVS) and metal accumulation in invertebrates with different feeding behavior and ecological preferences. Natural sediments, pore water and surface water, together with benthic and epibenthic invertebrates were sampled at 28 Flemish lowland rivers. Different metals as well as metal binding sediment characteristics including AVS were measured and multiple regression was used to study their relationship with accumulated metals in the invertebrates taxa. Bioaccumulation in the benthic taxa was primarily influenced by total metal concentrations in the sediment. Regarding the epibenthic taxa metal accumulation was mostly explained by the more bioavailable metal fractions in both the sediment and the water. AVS concentrations were generally better correlated with metal accumulation in the epibenthic invertebrates, rather than with the benthic taxa. Our results indicated that the relation between AVS and metal accumulation in aquatic invertebrates is highly dependent on feeding behavior and ecology. - The relation between AVS and metal accumulation in aquatic invertebrates is highly dependent on feeding behavior and ecology.

  3. National Coral Reef Monitoring Program: Assessing and Monitoring Cryptic Reef Diversity of Colonizing Marine Invertebrates using Autonomous Reef Monitoring Structure (ARMS) Deployed at Coral Reef Sites across Wake Island from 2011-03-23 to 2014-03-19 (NCEI Accession 0162467)

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — Autonomous Reef Monitoring Structures (ARMS) are used to assess and monitor cryptic reef diversity of colonizing marine invertebrates in the Hawaiian and Mariana...

  4. National Coral Reef Monitoring Program: Assessing and Monitoring Cryptic Reef Diversity of Colonizing Marine Invertebrates using Autonomous Reef Monitoring Structure (ARMS) Deployed at Coral Reef Sites across the Hawaiian Archipelago from 2013-08-03 to 2016-09-24 (NCEI Accession 0162465)

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — Autonomous Reef Monitoring Structures (ARMS) are used to assess and monitor cryptic reef diversity of colonizing marine invertebrates in the Hawaiian and Mariana...

  5. National Coral Reef Monitoring Program: Assessing and Monitoring Cryptic Reef Diversity of Colonizing Marine Invertebrates using Autonomous Reef Monitoring Structure (ARMS) Deployed at Coral Reef Sites across the Hawaiian Archipelago from 2008-10-07 to 2013-09-13 (NCEI Accession 0162470)

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — Autonomous Reef Monitoring Structures (ARMS) are used to assess and monitor cryptic reef diversity of colonizing marine invertebrates in the Hawaiian and Mariana...

  6. National Coral Reef Monitoring Program: Assessing and Monitoring Cryptic Reef Diversity of Colonizing Marine Invertebrates using Autonomous Reef Monitoring Structure (ARMS) Deployed at Coral Reef Sites across American Samoa from 2012-04-03 to 2015-03-26 (NCEI Accession 0162468)

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — Autonomous Reef Monitoring Structures (ARMS) are used to assess and monitor cryptic reef diversity of colonizing marine invertebrates in the Hawaiian and Mariana...

  7. National Coral Reef Monitoring Program: Assessing and Monitoring Cryptic Reef Diversity of Colonizing Marine Invertebrates using Autonomous Reef Monitoring Structure (ARMS) Deployed at Coral Reef Sites across the Marianas Archipelago from 2011-04-07 to 2014-05-04 (NCEI Accession 0162461)

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — Autonomous Reef Monitoring Structures (ARMS) are used to assess and monitor cryptic reef diversity of colonizing marine invertebrates in the Hawaiian and Mariana...

  8. National Coral Reef Monitoring Program: Assessing and Monitoring Cryptic Reef Diversity of Colonizing Marine Invertebrates using Autonomous Reef Monitoring Structure (ARMS) Deployed at Coral Reef Sites across the Pacific Remote Island Areas from 2012-05-03 to 2015-04-28 (NCEI Accession 0162464)

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — Autonomous Reef Monitoring Structures (ARMS) are used to assess and monitor cryptic reef diversity of colonizing marine invertebrates in the Hawaiian and Mariana...

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

    Science.gov (United States)

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

    2010-02-01

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

  10. Relations between water physico-chemistry and benthic algal communities in a northern Canadian watershed: defining reference conditions using multiple descriptors of community structure.

    Science.gov (United States)

    Thomas, Kathryn E; Hall, Roland I; Scrimgeour, Garry J

    2015-09-01

    Defining reference conditions is central to identifying environmental effects of anthropogenic activities. Using a watershed approach, we quantified reference conditions for benthic algal communities and their relations to physico-chemical conditions in rivers in the South Nahanni River watershed, NWT, Canada, in 2008 and 2009. We also compared the ability of three descriptors that vary in terms of analytical costs to define algal community structure based on relative abundances of (i) all algal taxa, (ii) only diatom taxa, and (iii) photosynthetic pigments. Ordination analyses showed that variance in algal community structure was strongly related to gradients in environmental variables describing water physico-chemistry, stream habitats, and sub-watershed structure. Water physico-chemistry and local watershed-scale descriptors differed significantly between algal communities from sites in the Selwyn Mountain ecoregion compared to sites in the Nahanni-Hyland ecoregions. Distinct differences in algal community types between ecoregions were apparent irrespective of whether algal community structure was defined using all algal taxa, diatom taxa, or photosynthetic pigments. Two algal community types were highly predictable using environmental variables, a core consideration in the development of Reference Condition Approach (RCA) models. These results suggest that assessments of environmental impacts could be completed using RCA models for each ecoregion. We suggest that use of algal pigments, a high through-put analysis, is a promising alternative compared to more labor-intensive and costly taxonomic approaches for defining algal community structure.

  11. Biodiversity, Community and Trophic Structure of the Suprabenthos of the Gulf of Cádiz-Guadalquivir Estuary Coupled System: Linking Pelagic-Benthic and Terrestrial-Marine Ecosystems.

    Science.gov (United States)

    Vilas, C.

    2016-02-01

    Suprabenthos biodiversity and species densities on both offshore and coastal systems are largely unknown. Main components like mysids, euphasiids or amphipods are omnivorous and constitute a major dietary component for many benthic and pelagic fishes, mammals, cephalopods and decapods. Despite their relevant ecological role linking pelagic-benthic food webs, suprabenthos have been chronically undersampled and their components underrepresented and underestimated in food web models. Many pelagic and demersal species of high commercial and ecological interest at the Gulf of Cádiz (GoC) feed at a bottom scattering layer identified from 0 to 200 m depth and up to 50 km from coast, related to the Guadalquivir Estuary (GE) influence coastal area, and present life history cycles based on a sequential use of habitats from GoC to GE nursery area, may be adapted to match the horizontal migrations of key suprabenthos prey species. In order to understand the ecological mechanisms through which the GE-GoC coupled ecosystem would influence the recruitment of these fishery resources, the suprabenthos was sampled by suprabenthic sldege (200 μm) from the shallow estuary to 75 m depth during June, August and November of 2013. We identified up to 300 species (H index 0.4-2-9 and Beta diversity 0.55), being copepods, molluscs, cumacea, cladocera, poliquets, decapods, mysids and amphipods the most important groups by biomass (mg/m3), finding densities up to 32.9 mg/m3 for copepods, 6 for mysids and up to 100 mg/m3 for decapods. Multivariate analysis determines depth as the most important variable explaining community structure, decreasing biodiversity with depth, while for sites at depths species show seasonal horizontal migrations between GoC and GE, connecting terrestrial and marine ecosystems.

  12. Effects of black carbon on bioturbination-induced benthic fluxes of polychlorinated biphenyls

    NARCIS (Netherlands)

    Koelmans, A.A.; Jonker, M.T.O.

    2011-01-01

    It is unknown whether carbonaceous geosorbents, such as black carbon (BC) affect bioturbation by benthic invertebrates, thereby possibly affecting sediment–water exchange of sediment-bound contaminants. Here, we assess the effects of oil soot on polychlorinated biphenyl (PCB) mass transfer from

  13. Insects and other invertebrates

    Science.gov (United States)

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

    1985-01-01

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

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

    International Nuclear Information System (INIS)

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

    2016-01-01

    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. - Highlights: • Biota of stormwater ponds had higher levels of metals compared to natural lakes. • Bioaccumulation of metals did not affect the biodiversity of the water bodies. • Biota composition in stormwater ponds and natural lakes was indistinguishable. • Stormwater ponds can play a role for biodiversity similar to natural lakes.

  16. 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. Copyright © 2016. Published by Elsevier B.V.

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

    Energy Technology Data Exchange (ETDEWEB)

    Stephansen, Diana Agnete, E-mail: das@civil.aau.dk [Department of Civil Engineering, Aalborg University, Thomas Manns Vej 23, 9220 Aalborg East (Denmark); Nielsen, Asbjørn Haaning [Department of Civil Engineering, Aalborg University, Thomas Manns Vej 23, 9220 Aalborg East (Denmark); Hvitved-Jacobsen, Thorkild [Department of Environmental Engineering, Aalborg University, Fredrik Bajers Vej 7H, 9200 Aalborg East (Denmark); Pedersen, Morten Lauge; Vollertsen, Jes [Department of Civil Engineering, Aalborg University, Thomas Manns Vej 23, 9220 Aalborg East (Denmark)

    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. - Highlights: • Biota of stormwater ponds had higher levels of metals compared to natural lakes. • Bioaccumulation of metals did not affect the biodiversity of the water bodies. • Biota composition in stormwater ponds and natural lakes was indistinguishable. • Stormwater ponds can play a role for biodiversity similar to natural lakes.

  18. Trophic transfer of pyrene metabolites between aquatic invertebrates

    International Nuclear Information System (INIS)

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

    2013-01-01

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

  19. Impact of exploratory offshore drilling on benthic communities in the Minerva gas field, Port Campbell, Australia

    Energy Technology Data Exchange (ETDEWEB)

    Currie, D.R.; Isaacs, L.R. [Central Queensland Univ., Gladstone (Australia). Centre for Environmental Management

    2005-04-01

    Changes to benthic infauna caused by exploratory gas drilling operations in the Minerva field were examined experimentally using a BACI (before, after, control, impact) design. Analysis of 72 x 0.1 m{sup 2} Smith-McIntyre grab samples obtained from one pre-drilling and three post-drilling periods yielded a diverse fauna consisting of 196 invertebrate species and 5035 individuals. Changes to benthic community structure were assessed using ANOVA and nonmetric multidimensional scaling (MDS). The abundances of two common species (Apseudes sp. 1 and Prionospio coorilla) decreased significantly at the well-head site immediately after drilling. The size of these reductions in abundance ranged between 71% and 88%, and persisted for less than 4 months after drilling. A third common species (Katlysia sp. 1) increased in abundance 200 m east of the well-head following drilling. Most species occurred at densities too low to be analysed individually and so were pooled at higher taxonomic levels. Changes in the abundance of species aggregated by phylum varied, but significant declines in the most abundant phyla (Crustaceans and Polychaetes) of 45-73% were observed at all sites within a 100 m radius of the well-head following drilling. In most cases these changes became undetectable four months after drilling following species recruitments. MDS ordinations confirm that drilling related changes to benthic community structure are most pronounced at stations located closest to the well-head. Additionally, the ordinations indicate that modified communities persist at the well-head for more than 11 months following exploratory drilling. (author)

  20. Oceanographic and topographic conditions structure benthic meiofauna communities in the Weddell Sea, Bransfield Strait and Drake Passage (Antarctic)

    Science.gov (United States)

    Veit-Köhler, Gritta; Durst, Stephan; Schuckenbrock, Jan; Hauquier, Freija; Durán Suja, Laura; Dorschel, Boris; Vanreusel, Ann; Martínez Arbizu, Pedro

    2018-03-01

    The marine environment of the tip of the Antarctic Peninsula is characterised by three oceanographically distinct regions for which we linked continental-slope meiofaunal patterns and environmental drivers on a large scale (100-300 km among ecoregions). Samples for meiofauna communities and sediment analyses were collected with a multicorer, water-column data were derived from water samples and CTD recordings. Meiofauna communities including individuals from 19 higher taxa were compared to a set of 16 environmental variables. We detected significant differences between the communities of Weddell Sea and those of Bransfield Strait and Drake Passage. The amount of phytopigments in the sediment, their freshness and the silt and clay content were driving factors for this separation. The highest meiofauna abundances were found at slopes in the Weddell Sea. Food banks may facilitate high standing stocks. There, the highest ever recorded copepod percentages for the Antarctic were related to the highest phytopigment contents while nematodes were extremely abundant even in deeper sediment layers at stations with fresh organic material. For Bransfield Strait and Drake Passage a sampling scheme of slopes and adjacent troughs was applied. The two regions were divided into three geographical "areas" with the two "habitat" types investigated for each area. Multivariate non-parametric permutational analysis of variance (PERMANOVA) showed that in Bransfield Strait slope and trough meiofauna communities differed significantly in all geographical areas while in Drake Passage this was only the case in the East. These differences were explained best by the regionally and topographically distinct characteristics of 7 out of 11 water-column and sediment-bound factors related to sediment grain size, food quantity and quality, water temperature and salinity. Environmental drivers of the benthic habitat are dependent on large-scale oceanographic conditions and are thus sensitive to changes

  1. Abundance, size composition and benthic assemblages of two Mediterranean echinoids off the

    Directory of Open Access Journals (Sweden)

    Elzahrae Elmasry

    2015-12-01

    Full Text Available This study is concerned with the variability in abundance, size composition and benthic assemblages of two echinoid species, the common sea urchin Paracentrotus lividus (Lamarck, 1816 and black urchin Arbacia lixula (Linnaeus, 1758 in the Southeastern Mediterranean (SEM along the coast of Alexandria, Egypt. Four seasonal trips were made during the years 2014–2015 covering 55 km of the shore with depths ranging between 3 and 9 m. The sea urchin species composition, density and size structure and distribution were compared. The associated macrobenthic invertebrates with prominent presence and biomass were observed as well as other benthic fauna and flora associations. The present results showed that P. lividus was the dominant echinoid spatially and temporally. A. lixula showed frequent occurrence in Sidi Bishr and Sidi Gaber stations in the spring season. The most dominant size class was the medium to large-sized classes for P. lividus and large-sized classes for A. lixula. The commercial size for the edible P. lividus represented 33% of the sampled population. Furthermore, the most dominant macrobenthic assemblages beside the echinoid population were primarily oysters, sea cucumbers, and mussels. Beside these, assemblage of seaweeds (red, green, brown and crustose algae, Porifera, Cnidaria, Crustacea, other Echinodermata, Bivalvia, Gastropoda, Tunicata, Bryozoa and Annelida were found. The present study shows that the investigated area represents stable habitats for the echinoid population with rich and diversified algal assemblages as well as other potential food resources.

  2. Limited differences in fish and benthic communities and possible cascading effects inside and outside a protected marine area in Sagres (SW Portugal).

    Science.gov (United States)

    Gil Fernández, C; Paulo, D; Serrão, E A; Engelen, A H

    2016-03-01

    Marine protected areas (MPAs) are a relatively recent fisheries management and conservation tool for conservation of marine ecosystems and serve as experimental grounds to assess trophic cascade effects in areas were fishing is restricted to some extent. A series of descriptive field studies were performed to assess fish and benthic communities between two areas within a newly established MPA in SW Portugal. We characterized benthic macroalgal composition and determined the size, density and biomass of the main benthic predatory and herbivorous fish species as well as the main benthic herbivorous invertebrates to assess indications of top-down control on the phytobenthic assemblages. Fish species were identical inside and outside the MPA, in both cases Sarpa salpa was the most abundant fish herbivore and Diplodus spp. accounted for the great majority of the benthic predators. However, size and biomass of D. spp. were higher inside than outside the MPA. The main herbivorous invertebrate was the sea urchin Paracentrotus lividus, which was smaller and predominantly showing a crevice-dwelling behaviour in the MPA. In addition, P. lividus size frequency distribution showed a unimodal pattern outside and a bimodal pattern inside the MPA. We found significant differences in the algal assemblages between inside and outside the MPA, with higher abundance of turf and foliose algae inside, and articulated calcareous and corticated macrophytes outside the MPA, but no differences in the invasive Asparagopsis spp. The obtained results show differences in predatory fish and benthic community structure, but not in species richness, inside and outside the MPA. We hypothesize these differences lead to variation in species interactions: directly through predation and indirectly via affecting sea urchins behavioural patterns, predators might drive changes in macroalgal assemblages via trophic cascade in the study area. However due to non-biological differences between the two areas it

  3. Benthic meiofaunal community response to the cascading effects of herbivory within an algal halo system of the Great Barrier Reef.

    Science.gov (United States)

    Ollivier, Quinn R; Hammill, Edward; Booth, David J; Madin, Elizabeth M P; Hinchliffe, Charles; Harborne, Alastair R; Lovelock, Catherine E; Macreadie, Peter I; Atwood, Trisha B

    2018-01-01

    Benthic fauna play a crucial role in organic matter decomposition and nutrient cycling at the sediment-water boundary in aquatic ecosystems. In terrestrial systems, grazing herbivores have been shown to influence below-ground communities through alterations to plant distribution and composition, however whether similar cascading effects occur in aquatic systems is unknown. Here, we assess the relationship between benthic invertebrates and above-ground fish grazing across the 'grazing halos' of Heron Island lagoon, Australia. Grazing halos, which occur around patch reefs globally, are caused by removal of seagrass or benthic macroalgae by herbivorous fish that results in distinct bands of unvegetated sediments surrounding patch reefs. We found that benthic algal canopy height significantly increased with distance from patch reef, and that algal canopy height was positively correlated with the abundances of only one invertebrate taxon (Nematoda). Both sediment carbon to nitrogen ratios (C:N) and mean sediment particle size (μm) demonstrated a positive correlation with Nematoda and Arthropoda (predominantly copepod) abundances, respectively. These positive correlations indicate that environmental conditions are a major contributor to benthic invertebrate community distribution, acting on benthic communities in conjunction with the cascading effects of above-ground algal grazing. These results suggest that benthic communities, and the ecosystem functions they perform in this system, may be less responsive to changes in above-ground herbivorous processes than those previously studied in terrestrial systems. Understanding how above-ground organisms, and processes, affect their benthic invertebrate counterparts can shed light on how changes in aquatic communities may affect ecosystem function in previously unknown ways.

  4. Extinction and recolonization of maritime Antarctica in the limpet Nacella concinna (Strebel, 1908) during the last glacial cycle: toward a model of Quaternary biogeography in shallow Antarctic invertebrates.

    Science.gov (United States)

    González-Wevar, C A; Saucède, T; Morley, S A; Chown, S L; Poulin, E

    2013-10-01

    Quaternary glaciations in Antarctica drastically modified geographical ranges and population sizes of marine benthic invertebrates and thus affected the amount and distribution of intraspecific genetic variation. Here, we present new genetic information in the Antarctic limpet Nacella concinna, a dominant Antarctic benthic species along shallow ice-free rocky ecosystems. We examined the patterns of genetic diversity and structure in this broadcast spawner along maritime Antarctica and from the peri-Antarctic island of South Georgia. Genetic analyses showed that N. concinna represents a single panmictic unit in maritime Antarctic. Low levels of genetic diversity characterized this population; its median-joining haplotype network revealed a typical star-like topology with a short genealogy and a dominant haplotype broadly distributed. As previously reported with nuclear markers, we detected significant genetic differentiation between South Georgia Island and maritime Antarctica populations. Higher levels of genetic diversity, a more expanded genealogy and the presence of more private haplotypes support the hypothesis of glacial persistence in this peri-Antarctic island. Bayesian Skyline plot and mismatch distribution analyses recognized an older demographic history in South Georgia. Approximate Bayesian computations did not support the persistence of N. concinna along maritime Antarctica during the last glacial period, but indicated the resilience of the species in peri-Antarctic refugia (South Georgia Island). We proposed a model of Quaternary Biogeography for Antarctic marine benthic invertebrates with shallow and narrow bathymetric ranges including (i) extinction of maritime Antarctic populations during glacial periods; (ii) persistence of populations in peri-Antarctic refugia; and (iii) recolonization of maritime Antarctica following the deglaciation process. © 2013 John Wiley & Sons Ltd.

  5. Invertebrate welfare: an overlooked issue

    Directory of Open Access Journals (Sweden)

    Kelsey Horvath

    2013-03-01

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

  6. Appearance of new taxa: invertebrates, phytoplankton and bacteria in an alkaline, saline, meteorite crater lake, South Africa

    CSIR Research Space (South Africa)

    Oberholster, Paul J

    2009-04-01

    Full Text Available of purple sulphur bacteria in the lake. The absence of submerged and emergent aquatic macrophytes in the lake limits habitat diversity for attached diatoms in the littoral regions. Both the numbers of families and the density of the benthic invertebrates...

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

    African Journals Online (AJOL)

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

  8. 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.

  9. 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

  10. CASA in invertebrates.

    Science.gov (United States)

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

    2018-04-09

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

  11. Gastropod shells: a dynamic resource that helps shape benthic community structure. [Calliactis tricolor; Pagurus pollicaris; Calappa flammea; Octopus joubini; Panulirus argus

    Energy Technology Data Exchange (ETDEWEB)

    McLean, R

    1983-01-01

    Empty gastropod shells are an important resource for many animals in shallow benthic marine communities. Shells provide shelter for hermit crabs, octopuses, and fishes, provide attachment substratum for hermit crab symbionts, and directly or indirectly modify hermit crab predation. Creation of an empty shell due to predation of one gastropod on another and acquisition of that shell by a hermit crab are two key events in the subsequent use of that shell. Shells of different gastropod species and the species of hermit crab acquiring them affect the symbiont complement that attaches to the shell, which in turn may affect future shell use by other symbionts. Certain shell types worn by the hermit crab, Pagurus pollicaris Say, are positively associated with the symbiotic sea anemone, Calliactis tricolor (Lesueur), which protects the hermit crab from predation by the crab, Calappa flammea (Herbst), and possibly from the octopus, Octopus joubini Robson. Shells of other species of gastropods are resistant to being crushed by the spiny lobster, Panulirus argus (Latreille). The inter- and intraspecific interactions centered on the gastropod shell are termed a ''habitat web.'' The potential of the shell to limit the size and distribution of animal populations demonstrates how this resource helps shape community structure.

  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. Trophic transfer of toxic elements in the estuarine invertebrate and fish food web of Daliao River, Liaodong Bay, China

    International Nuclear Information System (INIS)

    Guo, Bobo; Jiao, Deqi; Wang, Jing; Lei, Kai; Lin, Chunye

    2016-01-01

    In order to study element accumulation and trophic transfer in the food web, sixteen benthic invertebrate species and nine fish species were collected from the Daliao River estuary for analysis of toxic elements and nitrogen stable isotope in the muscle tissue. The concentrations ranged between 1.44–17.98, 0.01–9.30, 0.17–36.15, 0.7–145.4, 0.01–0.33, 0.14–14.88, 0.10–2.51, 0.02–0.14, and 19.3–221.1 mg kg −1 for As, Cd, Cu, Hg, Ni, Pb, Sb, and Zn, respectively. As, Cd, Cu, and Zn were significantly higher in the benthic invertebrates than in fish, whereas Hg and Sb were significantly lower. In addition, the benthic invertebrates were characterized by the highest bioaccumulation factor (BAF) for Cd, whereas the fish were characterized by the highest BAF for Hg. A significant decrease in Cd, Cr, Cu, and Ni levels, and a significant increase in Hg and Sb levels were observed with increasing trophic levels. - Highlights: • Toxic elements and trophic level were determined in biota from Daliao River estuary. • Benthic invertebrates had higher As, Cd, Cu, Zn and lower Hg and Sb levels than fish. • Benthic invertebrates accumulated high As levels, while fish accumulated high Hg levels. • Cd, Cr, Cu, Ni levels decreased, and Hg and Sb levels increased with trophic levels.

  14. 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...... contains papers which cover other themes thus continuing with the spirit of the meetings in the Nordic Benthological Society (NORBS) by being an open forum for exchanging knowledge on all aspects of benthic ecology. Overall, we feel the proceeding contains a wide selection of very interesting papers...... representing the state-of-the-art of benthic ecology research within, and to a lesser degree, outside the Nordic countries. We wish to thank all the authors for their inspirational contributions to the proceeding, but we feel that a special thanks is due to the invited speakers for their readiness to produce...

  15. 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.

  16. Benthic assemblages of mega epifauna on the Oregon continental margin

    Science.gov (United States)

    Hemery, Lenaïg G.; Henkel, Sarah K.; Cochrane, Guy R.

    2018-01-01

    Environmental assessment studies are usually required by a country's administration before issuing permits for any industrial activities. One of the goals of such environmental assessment studies is to highlight species assemblages and habitat composition that could make the targeted area unique. A section of the Oregon continental slope that had not been previously explored was targeted for the deployment of floating wind turbines. We carried out an underwater video survey, using a towed camera sled, to describe its benthic assemblages. Organisms were identified to the lowest taxonomic level possible and assemblages described related to the nature of the seafloor and the depth. We highlighted six invertebrate assemblages and three fish assemblages. For the invertebrates within flat soft sediments areas we defined three different assemblages based on primarily depth: a broad mid-depth (98–315 m) assemblage dominated by red octopus, sea pens and pink shrimps; a narrower mid-depth (250–270 m) assemblage dominated by box crabs and various other invertebrates; and a deeper (310–600 m) assemblage dominated by sea urchins, sea anemones, various snails and zoroasterid sea stars. The invertebrates on mixed sediments also were divided into three different assemblages: a shallow (~100 m deep) assemblage dominated by plumose sea anemones, broad mid-depth (170–370 m) assemblage dominated by sea cucumbers and various other invertebrates; and, again, a narrower mid-depth (230–270 m) assemblage, dominated by crinoids and encrusting invertebrates. For the fish, we identified a rockfish assemblage on coarse mixed sediments at 170–370 m and another fish assemblage on smaller mixed sediments within that depth range (250–370 m) dominated by thornyheads, poachers and flatfishes; and we identified a wide depth-range (98–600 m) fish assemblage on flat soft sediments dominated by flatfishes, eelpouts and thornyheads. Three of these assemblages (the two

  17. Benthic assemblages of mega epifauna on the Oregon continental margin

    Science.gov (United States)

    Hemery, Lenaïg G.; Henkel, Sarah K.; Cochrane, Guy R.

    2018-05-01

    Environmental assessment studies are usually required by a country's administration before issuing permits for any industrial activities. One of the goals of such environmental assessment studies is to highlight species assemblages and habitat composition that could make the targeted area unique. A section of the Oregon continental slope that had not been previously explored was targeted for the deployment of floating wind turbines. We carried out an underwater video survey, using a towed camera sled, to describe its benthic assemblages. Organisms were identified to the lowest taxonomic level possible and assemblages described related to the nature of the seafloor and the depth. We highlighted six invertebrate assemblages and three fish assemblages. For the invertebrates within flat soft sediments areas we defined three different assemblages based on primarily depth: a broad mid-depth (98-315 m) assemblage dominated by red octopus, sea pens and pink shrimps; a narrower mid-depth (250-270 m) assemblage dominated by box crabs and various other invertebrates; and a deeper (310-600 m) assemblage dominated by sea urchins, sea anemones, various snails and zoroasterid sea stars. The invertebrates on mixed sediments also were divided into three different assemblages: a shallow ( 100 m deep) assemblage dominated by plumose sea anemones, broad mid-depth (170-370 m) assemblage dominated by sea cucumbers and various other invertebrates; and, again, a narrower mid-depth (230-270 m) assemblage, dominated by crinoids and encrusting invertebrates. For the fish, we identified a rockfish assemblage on coarse mixed sediments at 170-370 m and another fish assemblage on smaller mixed sediments within that depth range (250-370 m) dominated by thornyheads, poachers and flatfishes; and we identified a wide depth-range (98-600 m) fish assemblage on flat soft sediments dominated by flatfishes, eelpouts and thornyheads. Three of these assemblages (the two broad fish assemblages and the deep

  18. Swept away: ocean currents and seascape features influence genetic structure across the 18,000 Km Indo-Pacific distribution of a marine invertebrate, the black-lip pearl oyster Pinctada margaritifera.

    Science.gov (United States)

    Lal, Monal M; Southgate, Paul C; Jerry, Dean R; Bosserelle, Cyprien; Zenger, Kyall R

    2017-01-10

    Genetic structure in many widely-distributed broadcast spawning marine invertebrates remains poorly understood, posing substantial challenges for their fishery management, conservation and aquaculture. Under the Core-Periphery Hypothesis (CPH), genetic diversity is expected to be highest at the centre of a species' distribution, progressively decreasing with increased differentiation towards outer range limits, as populations become increasingly isolated, fragmented and locally adapted. The unique life history characteristics of many marine invertebrates such as high dispersal rates, stochastic survival and variable recruitment are also likely to influence how populations are organised. To examine the microevolutionary forces influencing population structure, connectivity and adaptive variation in a highly-dispersive bivalve, populations of the black-lip pearl oyster Pinctada margaritifera were examined across its ~18,000 km Indo-Pacific distribution. Analyses utilising 9,624 genome-wide SNPs and 580 oysters, discovered differing patterns of significant and substantial broad-scale genetic structure between the Indian and Pacific Ocean basins. Indian Ocean populations were markedly divergent (F st  = 0.2534-0.4177, p Pacific Ocean oysters, where basin-wide gene flow was much higher (F st  = 0.0007-0.1090, p Pacific Oceans respectively. Evaluation of genetic structure at adaptive loci for Pacific populations (89 SNPs under directional selection; F st  = 0.1012-0.4371, FDR = 0.05), revealed five clusters identical to those detected at neutral SNPs, suggesting environmental heterogeneity within the Pacific. Patterns of structure and connectivity were supported by Mantel tests of isolation by distance (IBD) and independent hydrodynamic particle dispersal simulations. It is evident that genetic structure and connectivity across the natural range of P. margaritifera is highly complex, and produced by the interaction of ocean currents, IBD and seascape

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

    Directory of Open Access Journals (Sweden)

    Roger N. Hughes

    2005-06-01

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

  20. Fine Sediment Input and Benthic Fauna Interactions at the Confluence of Two Large Rivers

    International Nuclear Information System (INIS)

    Blettler, M. C. M.; Amsler, M. L.; Ezcurra De Drago, I.; Drago, E.; Paira, A.; Espinola, L. A.; Eberle, E.; Szupiany, R.

    2016-01-01

    Several studies suggest that invertebrate abundance and richness are disrupted and reset at confluences. Thus, junctions contribute disproportionately to the overall aquatic biodiversity of the river. In general terms, authors have reported high abundance and diversity due to the major physical heterogeneity at junctions. However, data are still scarce and uncertainties are plentiful. The impact of a great input of fine sediments on the distribution patterns of benthic invertebrates at a river confluence was quantitatively analyzed herein. The junction of the subtropical Bermejo River (high suspended sediment load) with the large Paraguay River is the selected study area to achieve this aim. While diversity increased slightly downstream the junction (from 0.21 to 0.36), density and richness of the macro invertebrate assemblage significantly diminished downstream the confluence (from 29050 to 410 ind/m2; p< 0.05) due to the input of fine sediment from the Bermejo River (mean fine sediment increased downstream from 6.3 to 10.2 mg/L), causing a negatively impact on invertebrate assemblage. This study highlights the ecological importance of the sediment input effects on benthic invertebrates, a topic still poorly explored in river ecology. It is speculated that the spatial extent of the impact would be dependent upon the hydrological and sedimentological context, highly unequal between both rivers. New hypotheses should be tested through new studies considering different hydrological stages.

  1. 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...

  2. Louisiana ESI: INVERT (Invertebrate Polygons)

    Data.gov (United States)

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

  3. 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...

  4. 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...

  5. 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...

  6. Feeding by larvae of intertidal invertebrates: assessing their position in pelagic food webs.

    Science.gov (United States)

    Vargas, Cristian A; Manríquez, Patricio H; Navarrete, Sergio A

    2006-02-01

    One of the leading determinants of the structure and dynamics of marine populations is the rate of arrival of new individuals to local sites. While physical transport processes play major roles in delivering larvae to the shore, these processes become most important after larvae have survived the perils of life in the plankton, where they usually suffer great mortality. The lack of information regarding larval feeding makes it difficult to assess the effects of food supply on larval survival, or the role larvae may play in nearshore food webs. Here, we examine the spectrum of food sizes and food types consumed by the larvae of two intertidal barnacle species and of the predatory gastropod Concholepas concholepas. We conducted replicated experiments in which larvae were exposed to the food size spectrum (phytoplankton, microprotozoan and autotrophic picoplankton) found in nearshore waters in central Chile. Results show that barnacle nauplii and gastropod veligers are omnivorous grazers, incorporating significant fractions of heterotrophs in their diets. In accordance with their feeding mechanisms and body size, barnacle nauplii were able to feed on autotrophic picoplankton (concholepas larvae also consumed picoplankton cells, while competent larvae of this species ingested mostly the largest phytoplankton cells and heterotrophic protozoans. Results suggest that persistent changes in the structure of pelagic food webs can have important effects on the species-specific food availability for invertebrate larvae, which can result in large-scale differences in recruitment rates of a given species, and in the relative recruitment success of the different species that make up benthic communities.

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

    International Nuclear Information System (INIS)

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

    2014-01-01

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

  8. 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

  9. RUNX in Invertebrates.

    Science.gov (United States)

    Hughes, S; Woollard, A

    2017-01-01

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

  10. Associative Learning in Invertebrates

    Science.gov (United States)

    Hawkins, Robert D.; Byrne, John H.

    2015-01-01

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

  11. 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

  12. Benthic boundary layer modelling studies

    International Nuclear Information System (INIS)

    Richards, K.J.

    1984-01-01

    A numerical model has been developed to study the factors which control the height of the benthic boundary layer in the deep ocean and the dispersion of a tracer within and directly above the layer. This report covers tracer clouds of horizontal scales of 10 to 100 km. The dispersion of a tracer has been studied in two ways. Firstly, a number of particles have been introduced into the flow. The trajectories of these particles provide information on dispersion rates. For flow conditions similar to those observed in the abyssal N.E. Atlantic the diffusivity of a tracer was found to be 5 x 10 6 cm 2 s -1 for a tracer within the boundary layer and 8 x 10 6 cm 2 s -1 for a tracer above the boundary layer. The results are in accord with estimates made from current meter measurements. The second method of studying dispersion was to calculate the evolution of individual tracer clouds. Clouds within and above the benthic boundary layer often show quite different behaviour from each other although the general structure of the clouds in the two regions were found to have no significant differences. (author)

  13. Turbidites and Benthic Faunal Succession in the Deep Sea: An Ecological Paradox

    National Research Council Canada - National Science Library

    Young, David

    2001-01-01

    Characteristics of benthic faunal succession following turbidity flows in the deep sea will vary according to the composition of turbidite materials, the spatial scales of deposition, the structure...

  14. Benthic prey fish assessment, Lake Ontario 2013

    Science.gov (United States)

    Weidel, Brian C.; Walsh, Maureen; Connerton, Michael J.

    2014-01-01

    The 2013 benthic fish assessment was delayed and shortened as a result of the U.S. Government shutdown, however the assessment collected 51 of the 62 planned bottom trawls. Over the past 34 years, Slimy Sculpin abundance in Lake Ontario has fluctuated, but ultimately decreased by two orders of magnitude, with a substantial decline occurring in the past 10 years. The 2013 Slimy Sculpin mean bottom trawl catch density (0.001 ind.·m-2, s.d.= 0.0017, n = 52) and mean biomass density (0.015 g·m-2 , s.d.= 0.038, n = 52) were the lowest recorded in the 27 years of sampling using the original bottom trawl design. From 2011-2013, the Slimy Sculpin density and biomass density has decreased by approximately 50% each year. Spring bottom trawl catches illustrate Slimy Sculpin and Round Goby Neogobius melanostoma winter habitat overlaps for as much as 7 months out of a year, providing opportunities for competition and predation. Invasive species, salmonid piscivory, and declines in native benthic invertebrates are likely all important drivers of Slimy Sculpin population dynamics in Lake Ontario. Deepwater Sculpin Myoxocephalus thompsonii, considered rare or absent from Lake Ontario for 30 years, have generally increased over the past eight years. For the first time since they were caught in this assessment, Deepwater Sculpin density and biomass density estimates declined from the previous year. The 2013 abundance and density estimates for trawls covering the standard depths from 60m to 150m was 0.0001 fish per square meter and 0.0028 grams per square meter. In 2013, very few small (recruitment. Nonnative Round Gobies were first detected in the USGS/NYSDEC Lake Ontario spring Alewife assessment in 2002. Since that assessment, observations indicate their population has expanded and they are now found along the entire south shore of Lake Ontario, with the highest densities in U.S. waters just east of the Niagara River confluence. In the 2013 spring-based assessment, both the

  15. 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.

  16. Enhanced invertebrate prey production following estuarine restoration supports foraging for multiple species of juvenile salmonids (Oncorhynchus spp.)

    Science.gov (United States)

    Woo, Isa; Davis, Melanie; Ellings, Christopher S.; Nakai, Glynnis; Takekawa, John Y.; De La Cruz, Susan

    2018-01-01

    Estuaries provide crucial foraging resources and nursery habitat for threatened populations of anadromous salmon. As such, there has been a global undertaking to restore habitat and tidal processes in modified estuaries. The foraging capacity of these ecosystems to support various species of out-migrating juvenile salmon can be quantified by monitoring benthic, terrestrial, and pelagic invertebrate prey communities. Here, we present notable trends in the availability of invertebrate prey at several sites within a restoring large river delta in Puget Sound, Washington, U.S.A. Three years after the system was returned to tidal influence, we observed substantial additions to amphipod, copepod, and cumacean abundances in newly accessible marsh channels (from 0 to roughly 5,000–75,000 individuals/m2). In the restoration area, terrestrial invertebrate colonization was dependent upon vegetative cover, with dipteran and hymenopteran biomass increasing 3-fold between 1 and 3 years post-restoration. While the overall biodiversity within the restoration area was lower than in the reference marsh, estimated biomass was comparable to or greater than that found within the other study sites. This additional prey biomass likely provided foraging benefits for juvenile Chinook, chum, and coho salmon. Primary physical drivers differed for benthic, terrestrial, and pelagic invertebrates, and these invertebrate communities are expected to respond differentially depending on organic matter exchange and vegetative colonization. Restoring estuaries may take decades to meet certain success criteria, but our study demonstrates rapid enhancements in foraging resources understood to be used for estuary-dependent wildlife.

  17. Gene expression of benthic amphipods (genus: Diporeia in relation to a circular ssDNA virus across two Laurentian Great Lakes

    Directory of Open Access Journals (Sweden)

    Kalia S.I. Bistolas

    2017-09-01

    Full Text Available Circular rep-encoding ssDNA (CRESS-DNA viruses are common constituents of invertebrate viral consortia. Despite their ubiquity and sequence diversity, the effects of CRESS-DNA viruses on invertebrate biology and ecology remain largely unknown. This study assessed the relationship between the transcriptional profile of benthic amphipods of genus Diporeia and the presence of the CRESS-DNA virus, LM29173, in the Laurentian Great Lakes to provide potential insight into the influence of these viruses on invertebrate gene expression. Twelve transcriptomes derived from Diporeia were compared, representing organisms from two amphipod haplotype clades (Great Lakes Michigan and Superior, defined by COI barcode sequencing with varying viral loads (up to 3 × 106 genome copies organism−1. Read recruitment to de novo assembled transcripts revealed 2,208 significantly over or underexpressed contigs in transcriptomes with above average LM29173 load. Of these contigs, 31.5% were assigned a putative function. The greatest proportion of annotated, differentially expressed transcripts were associated with functions including: (1 replication, recombination, and repair, (2 cell structure/biogenesis, and (3 post-translational modification, protein turnover, and chaperones. Contigs putatively associated with innate immunity displayed no consistent pattern of expression, though several transcripts were significantly overexpressed in amphipods with high viral load. Quantitation (RT-qPCR of target transcripts, non-muscular myosin heavy chain, β-actin, and ubiquitin-conjugating enzyme E2, corroborated transcriptome analysis and indicated that Lake Michigan and Lake Superior amphipods with high LM29173 load exhibit lake-specific trends in gene expression. While this investigation provides the first comparative survey of the transcriptional profile of invertebrates of variable CRESS-DNA viral load, additional inquiry is required to define the scope of host

  18. 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

  19. The Impact of Global Warming and Anoxia on Marine Benthic Community Dynamics: an Example from the Toarcian (Early Jurassic)

    Science.gov (United States)

    Danise, Silvia; Twitchett, Richard J.; Little, Crispin T. S.; Clémence, Marie-Emilie

    2013-01-01

    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. PMID:23457537

  20. 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). © 2012 The Authors. Journal of Fish Biology © 2012 The Fisheries Society of the British Isles.

  1. Interdependence of specialization and biodiversity in Phanerozoic marine invertebrates.

    Science.gov (United States)

    Nürnberg, Sabine; Aberhan, Martin

    2015-03-17

    Studies of the dynamics of biodiversity often suggest that diversity has upper limits, but the complex interplay between ecological and evolutionary processes and the relative role of biotic and abiotic factors that set upper limits to diversity are poorly understood. Here we statistically assess the relationship between global biodiversity and the degree of habitat specialization of benthic marine invertebrates over the Phanerozoic eon. We show that variation in habitat specialization correlates positively with changes in global diversity, that is, times of high diversity coincide with more specialized faunas. We identify the diversity dynamics of specialists but not generalists, and origination rates but not extinction rates, as the main drivers of this ecological interdependence. Abiotic factors fail to show any significant relationship with specialization. Our findings suggest that the overall level of specialization and its fluctuations over evolutionary timescales are controlled by diversity-dependent processes--driven by interactions between organisms competing for finite resources.

  2. Alternative adaptive immunity in invertebrates

    DEFF Research Database (Denmark)

    Kurtz, Joachim; Armitage, Sophie Alice Octavia

    2006-01-01

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

  3. Upwelling and Other Environmental Influences on Growth of a Nearshore Benthic Fish

    Science.gov (United States)

    von Biela, V. R.; Zimmerman, C. E.; Kruse, G. H.; Mueter, F. J.; Black, B.; Douglas, D. C.; Bodkin, J. L.

    2016-02-01

    The role of upwelling in nearshore benthic systems is more uncertain compared to the relatively strong positive associations with pelagic production. To understand how upwelling and other environmental conditions influence nearshore benthic production, we developed an annual index of production from growth increments recorded in otoliths of kelp greenling (Hexagrammos decagrammus) at nine sites in the seasonally-upwelling California Current and downwelling Alaska Coastal currents. Kelp greenling are a benthic-feeding fish common in kelp forests with food webs sustained by both kelp and phytoplankton primary production. We explored the influence of basin- and local-scale conditions, including upwelling, across all seasons at lags up to two years taken to represent changes in the quantity and quality of prey. Upwelling strength was positively related to fish growth in both current systems, although relationships in the Alaska Coastal Current were indicative of faster growth with relaxed downwelling, rather than upwelling. Looking across a suite of basin- and local-scale environmental indicators, complex relationships emerged in the California Current, with faster growth related to within-year warm conditions and lagged-year cool conditions. In contrast, fish in the downwelling system grew faster both during and subsequent to warm conditions. The complex lag-dependent dynamics in the upwelling system may reflect differences in conditions that promote quantity versus quality of benthic invertebrate prey. Thus, we hypothesize that benthic production is maximized when cool and warm years alternate during periods of high frequency climate variability in the California Current. Such a pattern is consistent with previous findings suggesting that benthic invertebrate abundance (e.g., recruitment) is food-limited during warm years with reduced upwelling, while quality (e.g., energy content) is temperature-limited during cool years.

  4. Inadequacy of diversity indices in discerning metal mine drainage effects on a steam invertebrate community

    Energy Technology Data Exchange (ETDEWEB)

    Chadwick, J.W.; Canton, S.P.

    1984-02-01

    The benthic invertebrates of the Dolores River in southwest Colorado were sampled during three seasons in an area of historic mine drainage. Benthic density exhibited significantly lower values below the mine drainage. However, the number of species did not decrease significantly, indicating that the effect of the mine drainage was primarily non-selective (i.e. favoring no one taxon). This pattern was seasonal with the least effects evident in summer and the greatest effects found in spring. Diversity indices used to assess the effects of this stress on the invertebrate community were Margalef's, Simpson's, Shannon-Weaver's, Brillouin's, and the Biotic Condition Index. None of the indices tested adequately responded to a decreasing trend in the benthic density when number of species remained constant. The indices did respond to a combination of low density and number of species or to the predominant representation by one species. The Biotic Condition Index actually increased at the stations with the lowest density and number of species. Diversity indices appear to be inadequate in assessing a non-selective stress.

  5. 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

  6. A comparative study of the contamination of some marine burrower invertebrates by cobalt 60 and cesium 137

    International Nuclear Information System (INIS)

    Amiard-Triquet, C.

    1975-01-01

    Experments were carried out with species whose mode of life is characterized by close contact with the sediments; they represent different zoological groups: an Annelid (Arenicola marina L.), an Echinoderm (Echinocardium cordatum Pennant) and two Lamellibranchs (Scrobicularia plana da Costa, Macoma balthica L.). The data obtained indicate that main vector of contamination of benthic marine invertebrates is water. The main part of these organisms in the sedimentary zone would be the redistribution, within the sediment, of radioelements adsorbed on the surface [fr

  7. Soil invertebrate communities in stressed European ecosystems

    Energy Technology Data Exchange (ETDEWEB)

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

    2003-07-01

    invertebrates but not in vertebrates and (2) in terrestrial food-webs of soil invertebrates - in first-order consumers - phytophagans and saprophagans. The tolerance of soil invertebrate communities to heavy metals as determined by universal mechanisms active on community (trophic structure, species diversity etc.), population (abundance, mass and sex structure of populations) and organism levels of organization is discussed. (orig.)

  8. 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

  9. Brain and behavioral lateralization in invertebrates.

    Science.gov (United States)

    Frasnelli, Elisa

    2013-12-11

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

  10. 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

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

    Science.gov (United States)

    Tassanakajon, Anchalee; Somboonwiwat, Kunlaya; Amparyup, Piti

    2015-02-01

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

  12. The functional significance of the spinose keel structure of benthic foraminifera: inferences from Miliolina cristata Millett, 1898 (Miliolida) from northeast Romania

    Science.gov (United States)

    Dumitriţa Dumitriu, Simina; Dubicka, Zofia; Ionesi, Viorel

    2018-01-01

    The paper presents Miocene (lower Sarmatian) benthic foraminifera from the FH3P1 Rădăuţi Core section from the northwestern part of the Moldavian Platform, Romania. Based on foraminiferal assemblages we infer sediments were deposited in shallow-water, including marine-marginal environments, of varying salinities from brackish to normal marine with some short and rather small sea-level changes. Moreover, we describe for the first time in the Moldavian Platform a very rare species, Miliolina cristata Millett, which presents a characteristic spinose keel. Based on a detailed study of the test morphology and its variability, observed in picked material as well as in thin sections, we discuss some palaeoecological aspects of these foraminifera. M. cristata probably does not constitute a distinctive species, but it is more probable that some miliolid taxa developed such an exoskeletal feature in response to new environmental conditions, such as more turbulent water. Accordingly, our study would support the thesis that one of the functions of the benthic foraminiferal spines is to stabilize foraminiferal tests found in sandy substrates from high-energy environments.

  13. 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.

  14. 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.

  15. Marine invertebrates: communities at risk.

    Science.gov (United States)

    Mather, Jennifer

    2013-06-10

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

  16. Patterns of deep-sea genetic connectivity in the New Zealand region: implications for management of benthic ecosystems.

    Directory of Open Access Journals (Sweden)

    Eleanor K Bors

    Full Text Available Patterns of genetic connectivity are increasingly considered in the design of marine protected areas (MPAs in both shallow and deep water. In the New Zealand Exclusive Economic Zone (EEZ, deep-sea communities at upper bathyal depths (<2000 m are vulnerable to anthropogenic disturbance from fishing and potential mining operations. Currently, patterns of genetic connectivity among deep-sea populations throughout New Zealand's EEZ are not well understood. Using the mitochondrial Cytochrome Oxidase I and 16S rRNA genes as genetic markers, this study aimed to elucidate patterns of genetic connectivity among populations of two common benthic invertebrates with contrasting life history strategies. Populations of the squat lobster Munida gracilis and the polychaete Hyalinoecia longibranchiata were sampled from continental slope, seamount, and offshore rise habitats on the Chatham Rise, Hikurangi Margin, and Challenger Plateau. For the polychaete, significant population structure was detected among distinct populations on the Chatham Rise, the Hikurangi Margin, and the Challenger Plateau. Significant genetic differences existed between slope and seamount populations on the Hikurangi Margin, as did evidence of population differentiation between the northeast and southwest parts of the Chatham Rise. In contrast, no significant population structure was detected across the study area for the squat lobster. Patterns of genetic connectivity in Hyalinoecia longibranchiata are likely influenced by a number of factors including current regimes that operate on varying spatial and temporal scales to produce potential barriers to dispersal. The striking difference in population structure between species can be attributed to differences in life history strategies. The results of this study are discussed in the context of existing conservation areas that are intended to manage anthropogenic threats to deep-sea benthic communities in the New Zealand region.

  17. NEPR Benthic Habitat Map 2015

    Data.gov (United States)

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

  18. 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...

  19. 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...

  20. Effects of urbanisation on macroalgae and sessile invertebrates in southeast Australian estuaries

    Science.gov (United States)

    Fowles, Amelia E.; Stuart-Smith, Rick D.; Stuart-Smith, Jemina F.; Hill, Nicole A.; Kirkpatrick, Jamie B.; Edgar, Graham J.

    2018-05-01

    The influence of anthropogenic and environmental factors on the composition, cover and dominance of macroalgae and sessile invertebrates was assessed in three capital city estuaries in south-eastern Australia. Heavy metals and proximity to ports showed the strongest relationships to the distribution of sessile reef biota after accounting for natural environmental gradients. The densities of laminarian, fucoid, brown and red foliose algae were negatively correlated with heavy metals, both in Port Phillip Bay (Melbourne) and the Derwent (Hobart), while turf, filamentous algae and some invertebrates were favoured. Sydney Harbour possessed a different pattern, with the laminarian kelp Ecklonia radiata most abundant near the main shipping port, probably because of biotic interactions involving urchin grazing in the lower estuary. Identifying drivers of benthic community pattern represents a key challenge for effective conservation management, particularly for estuaries affected by multiple anthropogenic impacts.

  1. 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...

  2. Diastereoisomer- and species-specific distribution of hexabromocyclododecane (HBCD) in fish and marine invertebrates.

    Science.gov (United States)

    Son, Min-Hui; Kim, Jongchul; Shin, Eun-Su; Seo, Sung-Hee; Chang, Yoon-Seok

    2015-12-30

    The levels and distributional characteristics of hexabromocyclododecane (HBCD) diastereoisomers have been largely reported for various fish and select shellfish. In this study, we reclassified a number and variety of marine invertebrates, including shellfish, to further contribute to the comprehensive understanding of the effects and assessment of human exposure to HBCD. Overall, 30 marine invertebrate species (n=188) were investigated and the following order of ∑2HBCD (α- and γ-HBCD) was observed: fish>chordata>cephalopoda>echinodermata>bivalve>crustacea. The marine invertebrates that were reclassified into nektonic and benthic organisms showed similar concentration of ∑2HBCD. The feeding habits and modes of the marine organisms were considered to compare the degree of bioaccumulation and diastereoisomer-specific distribution of HBCD due to the effects of the environment in and around pollution sources, as well as the organisms' metabolic capacities. To the best of our knowledge, this is the first study to examine the species-specific distribution patterns of HBCD for both fish and marine invertebrates. We expect to significantly expand the understanding of the environmental fate of HBCD for marine organisms. Copyright © 2015 Elsevier B.V. All rights reserved.

  3. Utilization of organic matter by invertebrates along an estuarine gradient in an intermittently open estuary

    Science.gov (United States)

    Lautenschlager, Agnes D.; Matthews, Ty G.; Quinn, Gerry P.

    2014-08-01

    In intermittently open estuaries, the sources of organic matter sustaining benthic invertebrates are likely to vary seasonally, particularly between periods of connection and disconnection with the ocean and higher and lower freshwater flows. This study investigated the contribution of allochthonous and autochthonous primary production to the diet of representative invertebrate species using stable isotope analysis (SIA) during the austral summer and winter (2008, 2009) in an intermittently open estuary on the south-eastern coast of Australia. As the study was conducted towards the end of a prolonged period of drought, a reduced influence of freshwater/terrestrial organic matter was expected. Sampling was conducted along an estuarine gradient, including upper, middle and lower reaches and showed that the majority of assimilated organic matter was derived from autochthonous estuarine food sources. Additionally, there was an input of allochthonous organic matter, which varied along the length of the estuary, indicated by distinct longitudinal trends in carbon and nitrogen stable isotope signatures along the estuarine gradient. Marine seaweed contributed to invertebrate diets in the lower reaches of the estuary, while freshwater/terrestrial organic matter had increased influence in the upper reaches. Suspension-feeding invertebrates derived large parts of their diet from freshwater/terrestrial material, despite flows being greatly reduced in comparison with non-drought years.

  4. 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

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

    Science.gov (United States)

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

    2018-07-01

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

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

    KAUST Repository

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

    2013-01-01

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

  7. Molecular Basis for Ultraviolet Vision in Invertebrates

    OpenAIRE

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

    2003-01-01

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

  8. Marine benthic faunal successional stages and related sedimentary activity

    Directory of Open Access Journals (Sweden)

    Rutger Rosenberg

    2001-12-01

    Full Text Available This paper is a brief review of successional stages and activity of benthic soft-bottom communities. Benthic communities was first described by Petersen in the 1910s and further developed by Molander, Thorson and Margalef. Successional stages of benthic communities chance in a predictable way in relation to environmental disturbance and food availability. Food supply to the bottom can occur as a vertical flux, but transport through lateral advection is more important in some areas. While at the bottom, the infauna processes the food in many different ways, and the feeding modes can be categorised into more than 20 functional groups, but fewer are present in brackish water. This categorisation is based on animal mobility and where and how they ingest the food. Animal activity in the sediment, bioturbation, has a significant effect on redox conditions and diagenetic processes. Structures in the sediment due to infaunal presence and activity can be observed in situ by sediment profile imaging, and the biogenic structures and redox conditions can be parameterised and have been shown to correlate to benthic community successional stages. The largest threat to benthic faunal biodiversity is the spread of near-bottom oxygen deficiency in many enclosed are stratified coastal areas.

  9. Benthic algae compensate for phytoplankton losses in large aquatic ecosystems.

    Science.gov (United States)

    Brothers, Soren; Vadeboncoeur, Yvonne; Sibley, Paul

    2016-12-01

    Anthropogenic activities can induce major trophic shifts in aquatic systems, yet we have an incomplete understanding of the implication of such shifts on ecosystem function and on primary production (PP) in particular. In recent decades, phytoplankton biomass and production in the Laurentian Great Lakes have declined in response to reduced nutrient concentrations and invasive mussels. However, the increases in water clarity associated with declines in phytoplankton may have positive effects on benthic PP at the ecosystem scale. Have these lakes experienced oligotrophication (a reduction of algal production), or simply a shift in autotrophic structure with no net decline in PP? Benthic contributions to ecosystem PP are rarely measured in large aquatic systems, but our calculations based on productivity rates from the Great Lakes indicate that a significant proportion (up to one half, in Lake Huron) of their whole-lake production may be benthic. The large declines (5-45%) in phytoplankton production in the Great Lakes from the 1970s to 2000s may be substantially compensated by benthic PP, which increased by up to 190%. Thus, the autotrophic productive capacity of large aquatic ecosystems may be relatively resilient to shifts in trophic status, due to a redirection of production to the near-shore benthic zone, and large lakes may exhibit shifts in autotrophic structure analogous to the regime shifts seen in shallow lakes. © 2016 John Wiley & Sons Ltd.

  10. 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

  11. Toxicity of Engineered Nanoparticles to Aquatic Invertebrates

    DEFF Research Database (Denmark)

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

    2016-01-01

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

  12. Managing mangroves with benthic biodiversity in mind: Moving beyond roving banditry

    Science.gov (United States)

    Ellison, Aaron M.

    2008-02-01

    This review addresses mangrove management activities in the broader context of the diversity of the mangrove benthos. Goals for mangrove ecosystem management include silviculture, aquaculture, or 'ecosystem services' such as coastal protection. Silvicultural management of mangroves generally neglects the benthos, although benthic invertebrates may affect tree establishment and growth, and community composition of benthic invertebrates may be a reliable indicator of the state of managed mangrove forests. Similarly, mangrove aquaculture focuses on particular species with little attention paid either to impacts on other trophic levels or to feedbacks with the trees. Exploitation of mangrove-associated prawns, crabs, and molluscs has a total economic value > US $4 billion per year. These aquaculture operations still rely on wild-collected stock; world-wide patterns of exploitation fit the well-known process of 'roving banditry', where mobile agents move from location to location, rapidly exploiting and depleting local resources before moving on to other, as-yet unprotected grounds. Collection of brood stock and fishing for other external inputs required by aquaculture (e.g., 'trash fish') removes intermediate trophic levels from marine food webs, may destabilize them, and lead to secondary extinctions of higher-order predators. Increased attention being paid to the role of mangroves in coastal protection following the 2004 Indian Ocean tsunami provides an opportunity to reassess the relative merits of management focused on short-term economic gains. Managing for ecosystem services may ultimately preserve benthic biodiversity in mangrove ecosystems.

  13. 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.

  14. The effects of hydrological dynamics on benthic diatom community structure in a highly stratified estuary: The case of the Ebro Estuary (Catalonia, Spain)

    Science.gov (United States)

    Rovira, L.; Trobajo, R.; Leira, M.; Ibáñez, C.

    2012-04-01

    This study of the distribution of benthic diatom assemblages and their relationship with environmental factors in a highly stratified Mediterranean estuary, i.e. the Ebro Estuary, shows the importance of hydrological dynamics to explain the features of the diatom community in such an estuary, where river flow magnitude and fluctuations imply strong physicochemical variability especially in sites close to the sea. Eight sites along the estuary were sampled during 2007-2008 both at superficial and deep water layers, in order to gather both horizontal and vertical estuarine physicochemical and hydrological gradients. Canonical Variates Analysis and Hierarchical Cluster Analysis segregated diatom community in two assemblages depending on the dynamics of the salt-wedge. The diatom assemblages of riverine conditions (i.e. without salt-wedge influence) where characterised by high abundances of Cocconeis placentula var. euglypta and Amphora pediculus, meanwhile high abundances of Nizschia frustulum and Nitzschia inconspicua were characteristic of estuarine conditions (i.e. under salt-wedge influence). Redundancy Analysis showed that both diatom assemblages responded seasonally to Ebro River flows, especially in estuarine conditions, where fluctuating conditions affected diatom assemblages both at spatial and temporal scale.

  15. Does reef architectural complexity influence resource availability for a large reef-dwelling invertebrate?

    Science.gov (United States)

    Lozano-Álvarez, Enrique; Luviano-Aparicio, Nelia; Negrete-Soto, Fernando; Barradas-Ortiz, Cecilia; Aguíñiga-García, Sergio; Morillo-Velarde, Piedad S.; Álvarez-Filip, Lorenzo; Briones-Fourzán, Patricia

    2017-10-01

    In coral reefs, loss of architectural complexity and its associated habitat degradation is expected to affect reef specialists in particular due to changes in resource availability. We explored whether these features could potentially affect populations of a large invertebrate, the spotted spiny lobster Panulirus guttatus, which is an obligate Caribbean coral reef-dweller with a limited home range. We selected two separate large coral reef patches in Puerto Morelos (Mexico) that differed significantly in structural complexity and level of degradation, as assessed via the rugosity index, habitat assessment score, and percent cover of various benthic components. On each reef, we estimated density of P. guttatus and sampled lobsters to analyze their stomach contents, three different condition indices, and stable isotopes (δ15N and δ13C) in muscle. Lobster density did not vary with reef, suggesting that available crevices in the less complex patch still provided adequate refuge to these lobsters. Lobsters consumed many food types, dominated by mollusks and crustaceans, but proportionally more crustaceans (herbivore crabs) in the less complex patch, which had more calcareous macroalgae and algal turf. Lobsters from both reefs had a similar condition (all three indices) and mean δ15N, suggesting a similar quality of diet between reefs related to their opportunistic feeding, but differed in mean δ13C values, reflecting the different carbon sources between reefs and providing indirect evidence of individuals of P. guttatus foraging exclusively over their home reef. Overall, we found no apparent effects of architectural complexity, at least to the degree observed in our less complex patch, on density, condition, or trophic level of P. guttatus.

  16. Interactions among zebra mussel shells, invertebrate prey, and Eurasian ruffe or yellow perch

    Science.gov (United States)

    Kolar, C.S.; Fullerton, A.H.; Martin, K.M.; Lamberti, G.A.

    2002-01-01

    The exotic zebra mussel, Dreissena polymorpha, is established in all of the Laurentian Great Lakes and may affect benthivorous fishes by increasing the complexity of benthic substrates and changing energy flow patterns within the food web. Native yellow perch, Perca flavescens, and the nonindigenous Eurasian ruffe, Gymnocephalus cernuus, are benthivores that may compete for limited food resources. As ruffe spread to areas with more dense zebra mussel populations, the zone of interaction among zebra mussels, yellow perch, and ruffe will increase and intensify. In the laboratory, the effect of zebra mussel shells on the ability of these fishes to forage on amphipods (Gammarus pseudolimnaeus) and chironomids (Chironomus plumosus) was examined in light and darkness. In 12 h, ruffe consumed more amphipods than did similar-sized yellow perch, particularly in darkness on bare cobble, and in light within zebra mussels. Amphipods decreased activity more in the presence of ruffe than yellow perch. More amphipods were found in zebra mussel shells than in bare cobble, whether or not fish were present. In darkness, when ruffe consumed more amphipods on bare cobble, amphipods became more associated with zebra mussel shells. Although ruffe consumed more amphipods than yellow perch, perch consumed more chironomids than ruffe on bare cobble. The presence of zebra mussel shells altered the relative consumption of invertebrates in some substrate-light combinations. Experiments such as these help to improve understanding of the direct and indirect effects of predation between and among native and nonindigenous species that may exert structuring forces on the nearshore communities of the Great Lakes currently or in the future.

  17. Effects of Pollution on Freshwater Invertebrates.

    Science.gov (United States)

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

    1978-01-01

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

  18. Invertebrates, ecosystem services and climate change.

    Science.gov (United States)

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

    2013-05-01

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

  19. Wood decomposition as influenced by invertebrates

    Science.gov (United States)

    Michael D. Ulyshen

    2014-01-01

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

  20. An invertebrate stomach's view on vertebrate ecology

    DEFF Research Database (Denmark)

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

    2013-01-01

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

  1. 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.

  2. Survival under stress : benthic foraminiferal patterns and Cenozoic biotic crises

    NARCIS (Netherlands)

    Kouwenhoven, T.J.

    2000-01-01

    A principal conclusion of this thesis is, that benthic foraminifera are excellent recorders of paleoenvironments and paleoenvironmental change. Insight in their community structure, and changes in this through time, is still increasing and will add to their usefulness in the reconstruction of past

  3. Survival under stress : benthic foraminiferal patterns and Cenozoic biotic crises

    NARCIS (Netherlands)

    Kouwenhoven, T.J.

    2000-01-01

    A principal conclusion of this thesis is, that benthic foraminifera are excellent recorders of paleoenvironments and paleoenvironmental change. Insight in their community structure, and changes in this through time, is still increasing and will add to their usefulness in the reconstruction of

  4. Benthic macroinvertebrate community and chlorophyll a (chl-a ...

    African Journals Online (AJOL)

    ADOWIE PERE

    consequences of climate change are some of the most visible warning signals ... present; spatial and temporal mobility of species is quite restricted, hence .... taxonomic groups using suitable identification manuals ... describe the structure and composition of benthic .... pollution respond to polluted environment by increase.

  5. The importance of benthic-pelagic coupling for marine ecosystem functioning in a changing world

    DEFF Research Database (Denmark)

    Griffiths, Jennifer R.; Kadin, Martina; Nascimento, Francisco J. A.

    2017-01-01

    and function is strongly affected by anthropogenic pressures, however there are large gaps in our understanding of the responses of inorganic nutrient and organic matter fluxes between benthic habitats and the water column. We illustrate the varied nature of physical and biological benthic-pelagic coupling...... processes and their potential sensitivity to three anthropogenic pressures - climate change, nutrient loading, and fishing - using the Baltic Sea as a case study, and summarize current knowledge on the exchange of inorganic nutrients and organic material between habitats. Traditionally measured benthic......Benthic-pelagic coupling is manifested as the exchange of energy, mass, or nutrients between benthic and pelagic habitats. It plays a prominent role in aquatic ecosystems and it is crucial to functions from nutrient cycling to energy transfer in food webs. Coastal and estuarine ecosystem structure...

  6. Invertebrate communities of Arctic tundra ponds as related to proximity to drill site reserve pits

    International Nuclear Information System (INIS)

    Byron, E.; Williams, N.; Hoffman, R.; Elder, B.

    1994-01-01

    Aquatic invertebrate communities were assessed for diversity and abundance in North Slope tundra ponds of Prudhoe Bay, Alaska during the summer of 1992 as part of an evaluation of potential effects of exposure to petroleum drill site reserve pits (previously used for storing drill site wastes). The invertebrate communities of these shallow, tundra ponds provide abundant food for migratory, aquatic birds that use this area during the summer breeding season. The study was designed to compare abundance and diversity estimates of invertebrates in ponds surrounding the drill sites that differed in distance (and presumed exposure) to drill site reserve pits. The pits, themselves, were not sampled as part of this study. Invertebrate abundance and diversity estimates, assessed as standard biological criteria, were evaluated relative to water chemistry of the ponds, distance to the gravel pads or reserve pits, and pond morphometry. The results indicated the importance of pond morphometry in determining the structure of the invertebrate community. Shallow, exposed ponds tended to be dominated by different invertebrate communities than deeper, narrow ponds at the margins of frost polygons. In contrast, pond chemistry and relative exposure to drill sites were not predictive of invertebrate abundance or diversity

  7. 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

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

    Science.gov (United States)

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

    2017-01-01

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

  9. The offshore benthic fish community

    Science.gov (United States)

    Lantry, Brian F.; Lantry, Jana R.; Weidel, Brian C.; Walsh, Maureen; Hoyle, James A.; Schaner, Teodore; Neave, Fraser B.; Keir, Michael

    2014-01-01

    Lake Ontario’s offshore benthic fish community includes primarily slimy sculpin, lake whitefish, rainbow smelt, lake trout, burbot, and sea lamprey. Of these, lake trout have been the focus of an international restoration effort for more than three decades (Elrod et al. 1995; Lantry and Lantry 2008). The deepwater sculpin and three species of deepwater ciscoes (Coregonus spp.) that were historically important in the offshore benthic zone became rare or were extirpated by the 1960s (Christie 1973; Owens et al. 2003; Lantry et al. 2007b; Roth et al. 2013). Ecosystem changes continue to influence the offshore benthic fish community, including the effects of dreissenid mussels, the near disappearance of burrowing amphipods (Diporeia spp.) (Dermott et al. 2005; Watkins et al. 2007), and the increased abundance and expanded geographic distribution of round goby (see Nearshore Fish Community chapter) (Lantry et al. 2007b). The fish-community objectives for the offshore benthic fish community, as described by Stewart et al. (1999), are:

  10. Ecotoxicological effect of grounded MV River Princess on the intertidal benthic organisms off Goa

    Digital Repository Service at National Institute of Oceanography (India)

    Ingole, B.S.; Sivadas, S.; Goltekar, R.; Clemente, S.; Nanajkar, M.; Sawant, R.; DeSilva, C.; Sarkar, A.; Ansari, Z.A.

    –biomass curves showed significant negative impact of TPH on macrofauna. The benthic community structure also showed measurable changes, as there was significant decrease (60%) in the number of species. Given that the microalgal counts were low in sediment...

  11. 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.

  12. Potential for parasite-induced biases in aquatic invertebrate population studies

    Science.gov (United States)

    Fisher, Justin D.L.; Mushet, David M.; Stockwell, Craig A.

    2014-01-01

    Recent studies highlight the need to include estimates of detection/capture probability in population studies. This need is particularly important in studies where detection and/or capture probability is influenced by parasite-induced behavioral alterations. We assessed potential biases associated with sampling a population of the amphipod Gammarus lacustris in the presence of Polymorphus spp. acanthocephalan parasites shown to increase positive phototaxis in their amphipod hosts. We trapped G. lacustris at two water depths (benthic and surface) and compared number of captures and number of parasitized individuals at each depth. While we captured the greatest number of G. lacustris individuals in benthic traps, parasitized individuals were captured most often in surface traps. These results reflect the phototaxic movement of infected individuals from benthic locations to sunlit surface waters. We then explored the influence of varying infection rates on a simulated population held at a constant level of abundance. Simulations resulted in increasingly biased abundance estimates as infection rates increased. Our results highlight the need to consider parasite-induced biases when quantifying detection and/or capture probability in studies of aquatic invertebrate populations.

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

    International Nuclear Information System (INIS)

    Pelletier, M.C.; Burgess, R.; Ho, K.; Kuhn, A.; McKinney, R.; Ryba, S.

    1995-01-01

    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

  14. Comparison of benthic indices for the evaluation of ecological status of three Slovenian transitional water bodies (northern Adriatic).

    Science.gov (United States)

    Pitacco, Valentina; Lipej, Lovrenc; Mavrič, Borut; Mistri, Michele; Munari, Cristina

    2018-04-01

    Benthic indicators are important tools for the classification of coastal and transitional water bodies. The aim of the work was to assess for the first time the Environmental Status (ES) of Slovenian transitional waters, comparing the following biotic indices: richness, Shannon-Weaver diversity, AMBI, M-AMBI, BENTIX and BITS indices. A total of 13 stations were sampled with a Van Veen grab, in three ecosystems in the northern Adriatic. Samples were sieved and sorted, invertebrates identified and counted. The anthropogenic impact was estimated with professional judgement. Richness and diversity showed a good response to anthropogenic pressure. Conversely, indices based on sensitivity/tolerance groups did not showed a clear distinction between more and less impacted ecosystems. In particular BENTIX underestimated the ES, while with BITS there was a overestimation. The best evaluation was obtained with M-AMBI, because even if based on a sensitivity/tolerance approach, it considered also the structural aspect of the community. Copyright © 2017 Elsevier Ltd. All rights reserved.

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

    Science.gov (United States)

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

    2015-12-01

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

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

    Science.gov (United States)

    Graf, Joerg

    2016-09-08

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

  17. Viral diseases of marine invertebrates

    Science.gov (United States)

    Johnson, P. T.

    1984-03-01

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

  18. 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

  19. Columbia River ESI: INVERT (Invertebrate Polygons)

    Data.gov (United States)

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

  20. Are invertebrates relevant models in ageing research?

    DEFF Research Database (Denmark)

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

    2016-01-01

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

  1. Immune Reactions Among Marine and Other Invertebrates

    Science.gov (United States)

    Bang, Frederik B.

    1973-01-01

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

  2. Uncoupling proteins of invertebrates: A review.

    Science.gov (United States)

    Slocinska, Malgorzata; Barylski, Jakub; Jarmuszkiewicz, Wieslawa

    2016-09-01

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

  3. Brain and behavioural lateralization in invertebrates.

    OpenAIRE

    Elisa eFrasnelli

    2013-01-01

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

  4. Brain and behavioral lateralization in invertebrates

    OpenAIRE

    Frasnelli, Elisa

    2013-01-01

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

  5. Evolution of transgenerational immunity in invertebrates

    OpenAIRE

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

    2016-01-01

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

  6. Toll-like receptors of deuterostome invertebrates

    Directory of Open Access Journals (Sweden)

    Honoo eSatake

    2012-02-01

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

  7. Organochlorines in benthic invertebrates and sediments from the Dutch Wadden Sea; identification of individual PCB components

    Science.gov (United States)

    Duinker, J. C.; Hillebrand, M. T. J.; Boon, J. P.

    Concentrations of organochlorines were determined in Macoma balthica, Arenicola marina, Crangon crangon and sediments from the Dutch Wadden Sea. Maximum concentrations of (total) PCB, γ-HCH and dieldrin were found in the western part; a pronounced maximum of HCB was found in the western part. Concentrations of PCB, p,p'-DDD and p,p'-DDE in sediment were correlated with the percentage of particles metabolism, were lower in Crangon. The patterns of pentachloro- and higher chlorinated biphenyls were equal in Macoma, Arenicola and sediments. Since these components are not found in solution, they must be taken up from sediment and food. The results are in agreement with partitioning between body lipids and water as the dominant mechanism determining concentrations of persistent lipophilic contaminants in the animals. Partitioning with the ambient water may also determine the concentrations in the sediment.

  8. Temporal and spatial responses of Chironomidae (Diptera) and other benthic invertebrates to urban stormwater runoff

    Science.gov (United States)

    Susan E. Gresens; Kenneth T. Belt; Jamie A. Tang; Daniel C. Gwinn; Patricia A. Banks

    2007-01-01

    In a longitudinal study of two streams whose lower reaches received unattenuated urban stormwater runoff, physical disturbance by stormflow was less important than the persistant unidentified chemical impacts of urban stormwater in limiting the distribution of Chironomidae, and Ephemeroptera, Trichoptera and Plecoptera (EPT). A hierarchical spatial analysis showed that...

  9. Interactions between crayfish, benthic invertebrates, macrophyte roots and sediment in a littoral zone

    Czech Academy of Sciences Publication Activity Database

    Ságová-Marečková, Markéta

    2002-01-01

    Roč. 155, č. 4 (2002), s. 645-665 ISSN 0003-9136 Grant - others:GA the Center for Limnology of the UW-Madison(XX) BSR8514330 Institutional research plan: CEZ:AV0Z5020903 Keywords : predation * food * crayfish Subject RIV: EE - Microbiology, Virology Impact factor: 1.195, year: 2002

  10. Macrophyte loss drives decadal change in benthic invertebrates in peatland drainage ditches

    NARCIS (Netherlands)

    Whatley, M.H.; van Loon, E.; van Dam, H.; Vonk, J.A.; van der Geest, H.G.; Admiraal, W.

    2014-01-01

    1. Agricultural peatlands and their associated drainage systems are often highly managed and exposed to anthropogenic pressures, such as eutrophication and stable water tables, maintained via drainage during periods of high rainfall and inlet of, alkaline-rich, waters during dry periods. These

  11. Influence of acid mine drainage, and its remediation on lakewater quality and benthic invertebrate communities

    Czech Academy of Sciences Publication Activity Database

    Mocq, Julien; Hare, L.

    2018-01-01

    Roč. 229, č. 2 (2018), č. článku 28. ISSN 0049-6979 Institutional support: RVO:60077344 Keywords : metals * benthos * acid mine drainage Subject RIV: EH - Ecology, Behaviour OBOR OECD: Ecology Impact factor: 1.702, year: 2016 https://link.springer.com/article/10.1007/s11270-017-3671-3

  12. PCB contamination and effects on benthic invertebrate communities at the Irving Whale salvage site

    National Research Council Canada - National Science Library

    Ernst, W

    2000-01-01

    In June of 1998 and 1999, two and three years after the raising of the Irving Whale, sediment sampling was conducted at the site where the barge was recovered to determine the extent and distribution...

  13. Field Report : Anna Plains and Roebuck Bay Benthic Invertebrate Mapping 2016

    NARCIS (Netherlands)

    Piersma, Theunis; Pearson, Grant B.; Lavaleye, Marc S. S.; Hickey, Robert; Rogers, Danny; Holthuijsen, Sander; Estrella, Sora-Marin; de Goeij, Petra; Findlay, Naomi; Storey, Andrew W.

    2016-01-01

    This project has been funded by the Department of Parks and Wildlife partnership with BHP Billiton “Eighty Mile Beach and Walyarta Conservation Program”, with in-kind support from NIOZ and Wetland Research & Management This report was produced at the Broome Bird Observatory in late October 2016.

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

    OpenAIRE

    Olson, John R.

    2012-01-01

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

  15. THE BENTHIC INVERTEBRATES OF THE SALTON SEA: DISTRIBUTION AND SEASONAL DYNAMICS. (R826552)

    Science.gov (United States)

    The perspectives, information and conclusions conveyed in research project abstracts, progress reports, final reports, journal abstracts and journal publications convey the viewpoints of the principal investigator and may not represent the views and policies of ORD and EPA. Concl...

  16. 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. Copyright © 2015 Elsevier Ltd. All rights reserved.

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

    Directory of Open Access Journals (Sweden)

    Bragina Tatyana М.

    2016-12-01

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

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

    Directory of Open Access Journals (Sweden)

    Carlinda Railly Ferreira Medeiros

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

  19. Benthic status of near-shore fishing grounds in the central Philippines and associated seahorse densities.

    Science.gov (United States)

    Marcus, J E; Samoilys, M A; Meeuwig, J J; Villongco, Z A D; Vincent, A C J

    2007-09-01

    Benthic status of 28 near-shore, artisanal, coral reef fishing grounds in the central Philippines was assessed (2000-2002) together with surveys of the seahorse, Hippocampus comes. Our measures of benthic quality and seahorse densities reveal some of the most degraded coral reefs in the world. Abiotic structure dominated the fishing grounds: 69% of the benthos comprised rubble (32%), sand/silt (28%) and dead coral (9%). Predominant biotic structure included live coral (12%) and Sargassum (11%). Rubble cover increased with increasing distance from municipal enforcement centers and coincided with substantial blast fishing in this region of the Philippines. Over 2 years, we measured a significant decrease in benthic 'heterogeneity' and a 16% increase in rubble cover. Poor benthic quality was concomitant with extremely low seahorse densities (524 fish per km(2)). Spatial management, such as marine reserves, may help to minimize habitat damage and to rebuild depleted populations of seahorses and other reef fauna.

  20. Antifouling phenyl ethers and other compounds from the invertebrates and their symbiotic fungi collected from the South China Sea

    KAUST Repository

    Wang, Chao-Yi; Wang, Kai-Ling; Ghosheh, Yanal; Xu, Ying; Chen, Min; Zheng, Juan-Juan; Liu, Min; Shao, Chang-Lun; Wang, Chang-Yun

    2016-01-01

    for their antifouling activities and security. These compounds include 44 natural products isolated from marine invertebrates and their symbiotic microorganisms collected from the South China Sea and 11 structural modified products derived from the isolated compounds

  1. Linking hydro-morphology with invertebrate ecology in diverse morphological units of a large river-floodplain system

    CSIR Research Space (South Africa)

    Blettler, MCM

    2016-12-01

    Full Text Available study were 1) to determine changes in invertebrate community due to hydrological stages, 2) to link local physical features [flow configuration, sediment composition and morphological feature) with the ecological structure between and within dissimilar...

  2. Hexabromocyclododecane affects benthic-pelagic coupling in an experimental ecosystem

    International Nuclear Information System (INIS)

    Bradshaw, Clare; Näslund, Johan; Hansen, Joakim; Kozlowsky-Suzuki, Betina; Sundström, Bo; Gustafsson, Kerstin

    2015-01-01

    Hexabromocyclododecane (HBCDD) is an additive brominated flame retardant and a recognized PBT chemical. However, little is known about its effects on coastal species, and even less on ecosystem effects. We investigated the dose–response effects of HBCDD over 8 months in 1000 L experimental mesocosms assembled from coastal Baltic Sea ecosystem components. HBCDD was added via spiked plankton material and a range of structural and functional endpoints were measured during the experiment. Increasing HBCDD concentration decreased the biomass of large Macoma balthica, resulting in a decreased recirculation of nutrients to the water. Changes in plankton communities were also observed, either due to direct toxic HBCDD effects or indirect via changes in benthic-pelagic coupling of nutrients. Such complex ecosystem responses can only be quantified and understood by using realistic experimental set-ups, and including knowledge of system-specific ecological interactions. This is the first study of HBCDD effects on ecosystem level. - Graphical abstract: HBCDD caused direct effects on the population structure of sediment-dwelling Macoma balthica and on the plankton community. Indirect HBCDD effects via reduced nutrient remineralization by M. balthica affected nutrient levels in the water, likely leading to additional changes in plankton community structure. Seasonal effects were large and affected the whole system including nutrient dynamics as well as plankton community structure. Display Omitted - Highlights: • HBCDD caused effects on benthic population structure and ecosystem function. • Large seasonal effects highlight the importance of using relevant experimental conditions. • A realistic exposure pathway was applied by using HBCDD enriched plankton material. • This is the first study of HBCDD effects on ecosystem level, coupling benthic and pelagic communities. - HBCDD has a dose-dependent effect on benthic-pelagic coupling.

  3. 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.

  4. THE STUDY OF WATER QUALITY USING BENTHIC MACROINVERTEBRATES AS BIOINDICATORS IN THE CATCHMENT AREAS OF THE RIVERS JIU, OLT AND IALOMIŢA

    Directory of Open Access Journals (Sweden)

    Elena Daniela MITITELU

    2012-01-01

    Full Text Available The wide distribution of benthic invertebrates and their different sensitivity shown upon modifying the qualitative parameters of aquatic ecosystems led to a frequent use of these group as bioindicators in different studies. The present study aims at presenting a list concerning the different macroinvertebrates identified in the larva stage in three watersheds (Jiu, Olt, Ialomiţa and establishing the water quality of the monitored sections using this benthic macroinvertebrates. The sample collecting points were represented by 23 stations. The abundance and frequency values recorded for benthic communities varied according to the physical-chemical conditions specific to each sample collecting station. There were identified 15 groups in total. The most frequent were Ephemeroptera, Plecoptera, Trichoptera, Diptera (Chironomidae and others. The deterioration of water quality is marked by the decrease in the biotic index EPT/Ch value.

  5. Benthic protists: the under-charted majority.

    Science.gov (United States)

    Forster, Dominik; Dunthorn, Micah; Mahé, Fréderic; Dolan, John R; Audic, Stéphane; Bass, David; Bittner, Lucie; Boutte, Christophe; Christen, Richard; Claverie, Jean-Michel; Decelle, Johan; Edvardsen, Bente; Egge, Elianne; Eikrem, Wenche; Gobet, Angélique; Kooistra, Wiebe H C F; Logares, Ramiro; Massana, Ramon; Montresor, Marina; Not, Fabrice; Ogata, Hiroyuki; Pawlowski, Jan; Pernice, Massimo C; Romac, Sarah; Shalchian-Tabrizi, Kamran; Simon, Nathalie; Richards, Thomas A; Santini, Sébastien; Sarno, Diana; Siano, Raffaele; Vaulot, Daniel; Wincker, Patrick; Zingone, Adriana; de Vargas, Colomban; Stoeck, Thorsten

    2016-08-01

    Marine protist diversity inventories have largely focused on planktonic environments, while benthic protists have received relatively little attention. We therefore hypothesize that current diversity surveys have only skimmed the surface of protist diversity in marine sediments, which may harbor greater diversity than planktonic environments. We tested this by analyzing sequences of the hypervariable V4 18S rRNA from benthic and planktonic protist communities sampled in European coastal regions. Despite a similar number of OTUs in both realms, richness estimations indicated that we recovered at least 70% of the diversity in planktonic protist communities, but only 33% in benthic communities. There was also little overlap of OTUs between planktonic and benthic communities, as well as between separate benthic communities. We argue that these patterns reflect the heterogeneity and diversity of benthic habitats. A comparison of all OTUs against the Protist Ribosomal Reference database showed that a higher proportion of benthic than planktonic protist diversity is missing from public databases; similar results were obtained by comparing all OTUs against environmental references from NCBI's Short Read Archive. We suggest that the benthic realm may therefore be the world's largest reservoir of marine protist diversity, with most taxa at present undescribed. © FEMS 2016. All rights reserved. For permissions, please e-mail: journals.permissions@oup.com.

  6. Wood decomposition as influenced by invertebrates.

    Science.gov (United States)

    Ulyshen, Michael D

    2016-02-01

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

  7. 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. Copyright 2010 Elsevier Ltd. All rights reserved.

  8. Accumulation of 210Po in Baltic invertebrates

    International Nuclear Information System (INIS)

    Skwarzec, B.; Falkowski, L.

    1988-01-01

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

  9. 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

  10. 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., ...

  11. Field trials to evaluate effects of continuously planted transgenic insect-resistant cottons on soil invertebrates.

    Science.gov (United States)

    Li, Xiaogang; Liu, Biao; Wang, Xingxiang; Han, Zhengmin; Cui, Jinjie; Luo, Junyu

    2012-03-01

    Impacts on soil invertebrates are an important aspect of environmental risk assessment and post-release monitoring of transgenic insect-resistant plants. The purpose of this study was to research and survey the effects of transgenic insect-resistant cottons that had been planted over 10 years on the abundance and community structure of soil invertebrates under field conditions. During 3 consecutive years (2006-2008), eight common taxa (orders) of soil invertebrates belonging to the phylum Arthropoda were investigated in two different transgenic cotton fields and one non-transgenic cotton field (control). Each year, soil samples were taken at four different growth stages of cotton (seedling, budding, boll forming and boll opening). Animals were extracted from the samples using the improved Tullgren method, counted and determined to the order level. The diversity of the soil fauna communities in the different fields was compared using the Simpson's, Shannon's diversity indices and evenness index. The results showed a significant sampling time variation in the abundance of soil invertebrates monitored in the different fields. However, no difference in soil invertebrate abundance was found between the transgenic cotton fields and the control field. Both sampling time and cotton treatment had a significant effect on the Simpson's, Shannon's diversity indices and evenness index. They were higher in the transgenic fields than the control field at the growth stages of cotton. Long-term cultivation of transgenic insect-resistant cottons had no significant effect on the abundance of soil invertebrates. Collembola, Acarina and Araneae could act as the indicators of soil invertebrate in this region to monitor the environmental impacts of transgenic plants in the future. This journal is © The Royal Society of Chemistry 2012

  12. InverPep: A database of invertebrate antimicrobial peptides.

    Science.gov (United States)

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

    2017-03-01

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

  13. Benthic fauna of 41 acid sensitive headwater lakes in north central Ontario. [Chironomidae salinarius; Chironomidae anthracinus; Tanytarsini

    Energy Technology Data Exchange (ETDEWEB)

    Dermott, R.; Kelso, J.R.M.; Douglas, A.

    1986-01-01

    The benthic fauna of 41 nonhumic, soft water lakes situated north of lakes Superior and Huron were sampled during 1980. The pH range of the lakes sampled was 4.6 to 7.7. The benthic infauna displayed regional differences in abundance and composition, with large variation with each district. Total abundance, biomass, and number of taxa were not correlated with lake pH or alkalinity. The Chironomidae displayed a slight change in percent composition of the major species with lower pH. The Tanytarsini and Chironomus Salinarius group decreased, while C. anthracinus group increased in relative abundance in those lakes with lower pH. Other factors appear to control the distribution of the various invertebrate orders, with depth and sediment nature being important variables.

  14. 76 FR 61379 - Final Recovery Plan, Bexar County Karst Invertebrates

    Science.gov (United States)

    2011-10-04

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

  15. Lanthanides, thorium, iodine in terrestrail invertebrates

    International Nuclear Information System (INIS)

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

    1991-01-01

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

  16. Evolution of transgenerational immunity in invertebrates.

    Science.gov (United States)

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

    2016-09-28

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

  17. Bromeliads in Caatinga: an oasis for invertebrates

    Directory of Open Access Journals (Sweden)

    Priscila Islair

    2014-11-01

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

  18. 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.

  19. Potential biocontrol agents for biofouling on artificial structures.

    Science.gov (United States)

    Atalah, Javier; Newcombe, Emma M; Hopkins, Grant A; Forrest, Barrie M

    2014-09-01

    The accumulation of biofouling on coastal structures can lead to operational impacts and may harbour problematic organisms, including non-indigenous species. Benthic predators and grazers that can supress biofouling, and which are able to be artificially enhanced, have potential value as augmentative biocontrol agents. The ability of New Zealand native invertebrates to control biofouling on marina pontoons and wharf piles was tested. Caging experiments evaluated the ability of biocontrol to mitigate established biofouling, and to prevent fouling accumulation on defouled surfaces. On pontoons, the gastropods Haliotis iris and Cookia sulcata reduced established biofouling cover by >55% and largely prevented the accumulation of new biofouling over three months. On wharf piles C. sulcata removed 65% of biofouling biomass and reduced its cover by 73%. C. sulcata also had better retention and survival rates than other agents. Augmentative biocontrol has the potential to be an effective method to mitigate biofouling on marine structures.

  20. Influence of benthic macrofauna community shifts on ecosystem functioning in shallow estuaries

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    Erik eKristensen

    2014-09-01

    Full Text Available We identify how ecosystem functioning in shallow estuaries is affected by shifts in benthic fauna communities. We use the shallow estuary, Odense Fjord, Denmark, as a case study to test our hypotheses that (1 shifts in benthic fauna composition and species functional traits affect biogeochemical cycling with cascading effects on ecological functioning, which may (2 modulate pelagic primary productivity with feedbacks to the benthic system. Odense Fjord is suitable because it experienced dramatic shifts in benthic fauna community structure from 1998 to 2008. We focused on infaunal species with emphasis on three dominating burrow-dwelling polychaetes: the native Nereis (Hediste diversicolor and Arenicola marina, and the invasive Marenzelleria viridis. The impact of functional traits in the form of particle reworking and ventilation on biogeochemical cycles, i.e. sediment metabolism and nutrient dynamics, was determined from literature data. Historical records of summer nutrient levels in the water column of the inner Odense Fjord show elevated concentrations of NH4+ and NO3- (DIN during the years 2004-2006, exactly when the N. diversicolor population declined and A. marina and M. viridis populations expanded dramatically. In support of our first hypothesis, we show that excess NH4+ delivery from the benthic system during the A. marina and M. viridis expansion period enriched the overlying water in DIN and stimulated phytoplankton concentration. The altered benthic-pelagic coupling and stimulated pelagic production may, in support of our second hypothesis, have feedback to the benthic system by changing the deposition of organic material. We therefore advice to identify the exact functional traits of the species involved in a community shift before studying its impact on ecosystem functioning. We also suggest studying benthic community shifts in shallow environments to obtain knowledge about the drivers and controls before exploring deep

  1. Contribution of benthic microalgae to the temporal variation in phytoplankton assemblages in a macrotidal system.

    Science.gov (United States)

    Hernández Fariñas, Tania; Ribeiro, Lourenço; Soudant, Dominique; Belin, Catherine; Bacher, Cédric; Lampert, Luis; Barillé, Laurent

    2017-10-01

    Suspended marine benthic microalgae in the water column reflect the close relationship between the benthic and pelagic components of coastal ecosystems. In this study, a 12-year phytoplankton time-series was used to investigate the contribution of benthic microalgae to the pelagic system at a site along the French-Atlantic coast. Furthermore, all taxa identified were allocated into different growth forms in order to study their seasonal patterns. The highest contribution of benthic microalgae was observed during the winter period, reaching up to 60% of the carbon biomass in the water column. The haptobenthic growth form showed the highest contribution in terms of biomass, dominant in the fall-winter period when the turbidity and the river flow were high. The epipelic growth form did not follow any seasonal pattern. The epiphytic diatom Licmophora was most commonly found during summer. As benthic microalgae were found in the water column throughout the year, the temporal variation detected in the structure of pelagic assemblages in a macrotidal ecosystem was partly derived from the differentiated contribution of several benthic growth forms. © 2017 Phycological Society of America.

  2. 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....

  3. Benthic habitat data for 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....

  4. Defensive Metabolites from Antarctic Invertebrates: Does Energetic Content Interfere with Feeding Repellence?

    Science.gov (United States)

    Núñez-Pons, Laura; Avila, Conxita

    2014-01-01

    Many bioactive products from benthic invertebrates mediating ecological interactions have proved to reduce predation, but their mechanisms of action, and their molecular identities, are usually unknown. It was suggested, yet scarcely investigated, that nutritional quality interferes with defensive metabolites. This means that antifeedants would be less effective when combined with energetically rich prey, and that higher amounts of defensive compounds would be needed for predator avoidance. We evaluated the effects of five types of repellents obtained from Antarctic invertebrates, in combination with diets of different energetic values. The compounds came from soft corals, ascidians and hexactinellid sponges; they included wax esters, alkaloids, a meroterpenoid, a steroid, and the recently described organic acid, glassponsine. Feeding repellency was tested through preference assays by preparing diets (alginate pearls) combining different energetic content and inorganic material. Experimental diets contained various concentrations of each repellent product, and were offered along with control compound-free pearls, to the Antarctic omnivore amphipod Cheirimedon femoratus. Meridianin alkaloids were the most active repellents, and wax esters were the least active when combined with foods of distinct energetic content. Our data show that levels of repellency vary for each compound, and that they perform differently when mixed with distinct assay foods. The natural products that interacted the most with energetic content were those occurring in nature at higher concentrations. The bioactivity of the remaining metabolites tested was found to depend on a threshold concentration, enough to elicit feeding repellence, independently from nutritional quality. PMID:24962273

  5. Defensive Metabolites from Antarctic Invertebrates: Does Energetic Content Interfere with Feeding Repellence?

    Directory of Open Access Journals (Sweden)

    Laura Núñez-Pons

    2014-06-01

    Full Text Available Many bioactive products from benthic invertebrates mediating ecological interactions have proved to reduce predation, but their mechanisms of action, and their molecular identities, are usually unknown. It was suggested, yet scarcely investigated, that nutritional quality interferes with defensive metabolites. This means that antifeedants would be less effective when combined with energetically rich prey, and that higher amounts of defensive compounds would be needed for predator avoidance. We evaluated the effects of five types of repellents obtained from Antarctic invertebrates, in combination with diets of different energetic values. The compounds came from soft corals, ascidians and hexactinellid sponges; they included wax esters, alkaloids, a meroterpenoid, a steroid, and the recently described organic acid, glassponsine. Feeding repellency was tested through preference assays by preparing diets (alginate pearls combining different energetic content and inorganic material. Experimental diets contained various concentrations of each repellent product, and were offered along with control compound-free pearls, to the Antarctic omnivore amphipod Cheirimedon femoratus. Meridianin alkaloids were the most active repellents, and wax esters were the least active when combined with foods of distinct energetic content. Our data show that levels of repellency vary for each compound, and that they perform differently when mixed with distinct assay foods. The natural products that interacted the most with energetic content were those occurring in nature at higher concentrations. The bioactivity of the remaining metabolites tested was found to depend on a threshold concentration, enough to elicit feeding repellence, independently from nutritional quality.

  6. Functional diversity of the macro‑invertebrate community in the port area of Kerkennah Islands (Tunisia

    Directory of Open Access Journals (Sweden)

    N. ALOUI‑BEJAOUI

    2012-04-01

    Full Text Available The harbour area of Sidi Youssef in Kerkennah islands is characterized by specific anthropogenic pressures linked to fishing activities. To study the functional diversity of benthic macro invertebrates, 10 stations located around the port and along the ship canal were sampled by SCUBA diving. Collected invertebrates were identified, counted and preserved. For the functional organization of the community, the most common biodiversity indices and functional groups were assessed at each station, and main physical and chemical parameters were measured. Results showed that the main apparent anthropogenic stress, that could lead to negative impacts on the studied area, was related to dredging/harbour activities. Suspension feeders, consisting essentially of polychaetes, which may be disturbed by water turbidity, dominated the stations farthest from the port, where the intensity of harbour activities is obviously reduced. On the contrary, carnivores dominated inside the port, possibly benefiting from fish scraps discarded at the area, while stations close to the port appeared to be more balanced trophically. The applied biotic indices showed that the area is in good ecological status, except of the navigation channel and the port entrance, which were slightly degraded.

  7. 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.

  8. Proteomics Insights: Proteins related to Larval Attachment and Metamorphosis of Marine Invertebrates

    Directory of Open Access Journals (Sweden)

    KONDETHIMMANAHALLI eCHANDRAMOULI

    2014-10-01

    Full Text Available 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 (PTM 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.

  9. Proteomics insights: proteins related to larval attachment and metamorphosis of marine invertebrates

    KAUST Repository

    Chandramouli, Kondethimmanahalli; Qian, Pei-Yuan; Ravasi, Timothy

    2014-01-01

    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.

  10. Enzyme-Assisted Discovery of Antioxidant Peptides from Edible Marine Invertebrates: A Review.

    Science.gov (United States)

    Chai, Tsun-Thai; Law, Yew-Chye; Wong, Fai-Chu; Kim, Se-Kwon

    2017-02-16

    Marine invertebrates, such as oysters, mussels, clams, scallop, jellyfishes, squids, prawns, sea cucumbers and sea squirts, are consumed as foods. These edible marine invertebrates are sources of potent bioactive peptides. The last two decades have seen a surge of interest in the discovery of antioxidant peptides from edible marine invertebrates. Enzymatic hydrolysis is an efficient strategy commonly used for releasing antioxidant peptides from food proteins. A growing number of antioxidant peptide sequences have been identified from the enzymatic hydrolysates of edible marine invertebrates. Antioxidant peptides have potential applications in food, pharmaceuticals and cosmetics. In this review, we first give a brief overview of the current state of progress of antioxidant peptide research, with special attention to marine antioxidant peptides. We then focus on 22 investigations which identified 32 antioxidant peptides from enzymatic hydrolysates of edible marine invertebrates. Strategies adopted by various research groups in the purification and identification of the antioxidant peptides will be summarized. Structural characteristic of the peptide sequences in relation to their antioxidant activities will be reviewed. Potential applications of the peptide sequences and future research prospects will also be discussed.

  11. The Early Shorebird Will Catch Fewer Invertebrates on Trampled Sandy Beaches.

    Science.gov (United States)

    Schlacher, Thomas A; Carracher, Lucy K; Porch, Nicholas; Connolly, Rod M; Olds, Andrew D; Gilby, Ben L; Ekanayake, Kasun B; Maslo, Brooke; Weston, Michael A

    2016-01-01

    Many species of birds breeding on ocean beaches and in coastal dunes are of global conservation concern. Most of these species rely on invertebrates (e.g. insects, small crustaceans) as an irreplaceable food source, foraging primarily around the strandline on the upper beach near the dunes. Sandy beaches are also prime sites for human recreation, which impacts these food resources via negative trampling effects. We quantified acute trampling impacts on assemblages of upper shore invertebrates in a controlled experiment over a range of foot traffic intensities (up to 56 steps per square metre) on a temperate beach in Victoria, Australia. Trampling significantly altered assemblage structure (species composition and density) and was correlated with significant declines in invertebrate abundance and species richness. Trampling effects were strongest for rare species. In heavily trafficked plots the abundance of sand hoppers (Amphipoda), a principal prey item of threatened Hooded Plovers breeding on this beach, was halved. In contrast to the consistently strong effects of trampling, natural habitat attributes (e.g. sediment grain size, compactness) were much less influential predictors. If acute suppression of invertebrates caused by trampling, as demonstrated here, is more widespread on beaches it may constitute a significant threat to endangered vertebrates reliant on these invertebrates. This calls for a re-thinking of conservation actions by considering active management of food resources, possibly through enhancement of wrack or direct augmentation of prey items to breeding territories.

  12. 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

  13. Transfer of radiocaesium from contaminated bottom sediments to marine organisms through benthic food chains in post-Fukushima and post-Chernobyl periods

    International Nuclear Information System (INIS)

    Bezhenar, Roman; Maderich, Vladimir; Jung, Kyung Tae; Willemsen, Stefan; With, Govert de; Qiao, Fangli

    2016-01-01

    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 "1"3"7Cs still remain in sediments, benthic organisms, and demersal fishes in the coastal zone around the FDNPP. These observations indicate that there are "1"3"7Cs 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 "1"3"7Cs released due to the FDNPP accident. The model simulations for activity concentrations of "1"3"7Cs 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

  14. Transfer of radiocaesium from contaminated bottom sediments to marine organisms through benthic food chains in post-Fukushima and post-Chernobyl periods

    Energy Technology Data Exchange (ETDEWEB)

    Bezhenar, Roman; Maderich, Vladimir [Institute of Mathematical Machine and System Problems, Kiev (Ukraine); Jung, Kyung Tae [Korea Institute of Ocean Science and Technology, Ansan (Korea, Republic of); Willemsen, Stefan; With, Govert de [NRG, Arnhem (Netherlands); Qiao, Fangli [First Institute of Oceanography, Qingdao (China)

    2016-07-01

    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 {sup 137}Cs still remain in sediments, benthic organisms, and demersal fishes in the coastal zone around the FDNPP. These observations indicate that there are {sup 137}Cs 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 {sup 137}Cs released due to the FDNPP accident. The model simulations for activity concentrations of {sup 137}Cs 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

  15. 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

  16. 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.

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

    Directory of Open Access Journals (Sweden)

    Curtean-Bănăduc Angela

    2014-12-01

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

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

    International Nuclear Information System (INIS)

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

    2006-01-01

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

  19. 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...

  20. Benthic studies in south Gujarat estuaries

    Digital Repository Service at National Institute of Oceanography (India)

    Govindan, K.; Varshney, P.K.; Desai, B.N.

    Benthic biomass and faunal composition in relation to various environmental conditions of the four South Gujarat estuaries namely the Auranga, Ambika, Purna and Mindola were studied and compared. Mean population density of benthos in Auranga, Ambika...

  1. Benthic carbonate factories of the Phanerozoic

    NARCIS (Netherlands)

    Schlager, W.

    2003-01-01

    Marine carbonate precipitation occurs in three basic modes: abiotic (or quasi-abiotic), biotically induced, and biotically controlled. On a geologic scale, these precipitation modes combine to form three carbonate production systems, or "factories" in the benthic environment: (1) tropical

  2. 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

  3. Enzyme Histochemistry for Functional Histology in Invertebrates.

    Science.gov (United States)

    Cima, Francesca

    2017-01-01

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

  4. Ethics and invertebrates: a cephalopod perspective.

    Science.gov (United States)

    Mather, Jennifer A; Anderson, Roland C

    2007-05-04

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

  5. The influence of multiple chemical and non-chemical stressors on benthic communities in a mid-west agricultural stream.

    Science.gov (United States)

    Hall, Lenwood W; Killen, Willian D; Anderson, Ronald D; Alden, Raymond W

    2017-08-24

    The objective of this 3-year study was to characterize benthic communities and physical habitat in an agricultural stream in the mid-west area of the United States (Big Bureau Creek, Illinois). Concurrent basic water quality parameters and seven nutrients were measured in the water column. Sediment measurements from depositional areas were conducted for bifenthrin, Total Organic Carbon, grain size, polychlorinated biphenyls (PCBs) and eight metals. All parameters were measured at 12 sites annually during the late summer for a 3-year period (2014, 2015 and 2016). Univariate regressions, stepwise multiple regressions and canonical correlation statistical analyses were used to determine the relationship between various benthic metrics (i.e., taxa richness and abundance) and all the measured parameters for the 3-year database. Benthic communities comprising 108-110 taxa were collected annually, and were generally dominated by sensitive caddisflies and mayflies. These communities were rated as good to exceptional using the Ohio Invertebrate Community Index. Physical habitat for the various sites was rated as good using the Ohio Qualitative Habitat Evaluation Index, thus suggesting that habitat is not a significant stressor that would likely impact resident benthic communities. Based on a comparison of measured in-stream total nitrogen and total phosphorus concentrations and criterion value exceedances, it appears that the in-stream nutrient concentrations could be potentially stressful to resident benthic biota. Metal concentrations were below established NOAA Threshold Effects Levels at all sites. Measured PCB concentrations were below levels of detection at all sites. Toxic units' (TUs) calculations based on using sensitive laboratory strains of Hyalella were less than 0.1 for bifenthrin, thus suggesting that bifenthrin sediment toxicity was unlikely. Thirty significant relationships reported between benthic metrics and the various environmental variables based on the

  6. 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

  7. Predicting invertebrate assemblage composition from harvesting pressure and environmental characteristics on tropical reef flats

    Science.gov (United States)

    Jimenez, H.; Dumas, P.; Ponton, D.; Ferraris, J.

    2012-03-01

    Invertebrates represent an essential component of coral reef ecosystems; they are ecologically important and a major resource, but their assemblages remain largely unknown, particularly on Pacific islands. Understanding their distribution and building predictive models of community composition as a function of environmental variables therefore constitutes a key issue for resource management. The goal of this study was to define and classify the main environmental factors influencing tropical invertebrate distributions in New Caledonian reef flats and to test the resulting predictive model. Invertebrate assemblages were sampled by visual counting during 2 years and 2 seasons, then coupled to different environmental conditions (habitat composition, hydrodynamics and sediment characteristics) and harvesting status (MPA vs. non-MPA and islets vs. coastal flats). Environmental conditions were described by a principal component analysis (PCA), and contributing variables were selected. Permutational analysis of variance (PERMANOVA) was used to test the effects of different factors (status, flat, year and season) on the invertebrate assemblage composition. Multivariate regression trees (MRT) were then used to hierarchically classify the effects of environmental and harvesting variables. MRT model explained at least 60% of the variation in structure of invertebrate communities. Results highlighted the influence of status (MPA vs. non-MPA) and location (islet vs. coastal flat), followed by habitat composition, organic matter content, hydrodynamics and sampling year. Predicted assemblages defined by indicator families were very different for each environment-exploitation scenario and correctly matched a calibration data matrix. Predictions from MRT including both environmental variables and harvesting pressure can be useful for management of invertebrates in coral reef environments.

  8. Building a database for long-term monitoring of benthic macrofauna in the Pertuis-Charentais (2004-2014).

    Science.gov (United States)

    Philippe, Anne S; Plumejeaud-Perreau, Christine; Jourde, Jérôme; Pineau, Philippe; Lachaussée, Nicolas; Joyeux, Emmanuel; Corre, Frédéric; Delaporte, Philippe; Bocher, Pierrick

    2017-01-01

    Long-term benthic monitoring is rewarding in terms of science, but labour-intensive, whether in the field, the laboratory, or behind the computer. Building and managing databases require multiple skills, including consistency over time as well as organisation via a systematic approach. Here, we introduce and share our spatially explicit benthic database, comprising 11 years of benthic data. It is the result of intensive benthic sampling that has been conducted on a regular grid (259 stations) covering the intertidal mudflats of the Pertuis-Charentais (Marennes-Oléron Bay and Aiguillon Bay). Samples were taken by foot or by boats during winter depending on tidal height, from December 2003 to February 2014. The present dataset includes abundances and biomass densities of all mollusc species of the study regions and principal polychaetes as well as their length, accessibility to shorebirds, energy content and shell mass when appropriate and available. This database has supported many studies dealing with the spatial distribution of benthic invertebrates and temporal variations in food resources for shorebird species as well as latitudinal comparisons with other databases. In this paper, we introduce our benthos monitoring, share our data, and present a "guide of good practices" for building, cleaning and using it efficiently, providing examples of results with associated R code. The dataset has been formatted into a geo-referenced relational database, using PostgreSQL open-source DBMS. We provide density information, measurements, energy content and accessibility of thirteen bivalve, nine gastropod and two polychaete taxa (a total of 66,620 individuals)​ for 11 consecutive winters. Figures and maps are provided to describe how the dataset was built, cleaned, and how it can be used. This dataset can again support studies concerning spatial and temporal variations in species abundance, interspecific interactions as well as evaluations of the availability of food

  9. Trophodynamics of Organic Pollutants in Pelagic and Benthic Food Webs of Lake Dianchi: Importance of Ingested Sediment As Uptake Route.

    Science.gov (United States)

    Fan, Senrong; Wang, Beili; Liu, Hang; Gao, Shixiong; Li, Tong; Wang, Shuran; Liu, Yong; Liu, Xueqin; Wan, Yi

    2017-12-19

    Habitat is of great importance in determining the trophic transfer of pollutants in freshwater ecosystems; however, the major factors influencing chemical trophodynamics in pelagic and benthic food webs remain unclear. This study investigated the levels of p,p'-dichlorodiphenyldichloroethylene (p,p'-DDE), polycyclic aromatic hydrocarbons (PAHs), and substituted PAHs (s-PAHs) in 2 plankton species, 6 invertebrate species, and 10 fish species collected from Lake Dianchi in southern China. Relatively high concentrations of PAHs and s-PAHs were detected with total concentrations of 11.4-1400 ng/g wet weight (ww) and 5.3-115 ng/g ww, respectively. Stable isotope analysis and stomach content analysis were applied to quantitatively determine the trophic level of individual organisms and discriminate between pelagic and benthic pathways, and the trophodynamics of the detected compounds in the two food webs were assessed. P,p'-DDE was found to exhibit relatively higher trophic magnification rate in the pelagic food web than in the benthic food web. In contrast, PAHs and s-PAHs exhibited greater dilution rates along the trophic levels in the pelagic food web. The lower species differences of pollutants accumulated in benthic organisms compared to pelagic organisms is attributable to extra uptake via ingested sediment in benthos. The average uptake proportions of PAHs and s-PAHs via ingested sediment in benthic biotas were estimated to be 31-77%, and that of p,p'-DDE was 46%. The uptake routes are of importance for assessing the trophic magnification potentials of organic pollutants, especially in eutrophic freshwater ecosystems.

  10. Effects of Feeding Strategy, Sediment Characteristics, and Chemical Properties on Polychlorinated Biphenyl and Polybrominated Diphenyl Ether Bioaccumulation from Marine Sediments in Two Invertebrates.

    Science.gov (United States)

    Frouin, H; Jackman, P; Dangerfield, N D; Ross, P S

    2017-08-01

    Shellfish and sediment invertebrates have been widely used to assess pollution trends over space and time in coastal environments around the world. However, few studies have compared the bioaccumulation potential of different test species over a range of sediment-contaminant concentrations and profiles. The bioavailability of sediment-related contaminants was evaluated using sediments collected from sites (n = 12) throughout the Salish Sea, British Columbia, Canada. Two benthic marine invertebrates-the Baltic clam Macoma balthica and the polychaete worm Neanthes arenaceodentata-were exposed for 28 days in a controlled environment to these field-collected coastal sediments. The congener-specific uptake of legacy polychlorinated biphenyls (PCBs) and emergent polybrominated diphenyl ethers (PBDEs) was determined using high-resolution gas chromatography/mass spectrometry in sediments and in invertebrates after the experimental exposure. The polychaete Neanthes accumulated lower concentrations of PCBs but higher concentrations of PBDEs. The present study indicates that differences in bioaccumulation between these two invertebrates shape the accumulation of PCB and PBDE congeners, reflect differences in feeding strategies, and reveal the physicochemical properties of the contaminants and sediment properties. Because biota-sediment accumulation factor values are often calculated for environmental monitoring or site-specific impact assessments, our results provide insight into potentially confounding factors and the need for caution when selecting indicator species for coastal marine pollution.

  11. 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

  12. A Vulnerability Assessment of Fish and Invertebrates to Climate Change on the Northeast U.S. Continental Shelf

    Science.gov (United States)

    Hare, Jonathan A.; Morrison, Wendy E.; Nelson, Mark W.; Stachura, Megan M.; Teeters, Eric J.; Griffis, Roger B.; Alexander, Michael A.; Scott, James D.; Alade, Larry; Bell, Richard J.; Chute, Antonie S.; Curti, Kiersten L.; Curtis, Tobey H.; Kircheis, Daniel; Kocik, John F.; Lucey, Sean M.; McCandless, Camilla T.; Milke, Lisa M.; Richardson, David E.; Robillard, Eric; Walsh, Harvey J.; McManus, M. Conor; Marancik, Katrin E.; Griswold, Carolyn A.

    2016-01-01

    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 results will inform

  13. Functional characterization on invertebrate and vertebrate tissues of tachykinin peptides from octopus venoms.

    Science.gov (United States)

    Ruder, Tim; Ali, Syed Abid; Ormerod, Kiel; Brust, Andreas; Roymanchadi, Mary-Louise; Ventura, Sabatino; Undheim, Eivind A B; Jackson, Timothy N W; Mercier, A Joffre; King, Glenn F; Alewood, Paul F; Fry, Bryan G

    2013-09-01

    It has been previously shown that octopus venoms contain novel tachykinin peptides that despite being isolated from an invertebrate, contain the motifs characteristic of vertebrate tachykinin peptides rather than being more like conventional invertebrate tachykinin peptides. Therefore, in this study we examined the effect of three variants of octopus venom tachykinin peptides on invertebrate and vertebrate tissues. While there were differential potencies between the three peptides, their relative effects were uniquely consistent between invertebrate and vertebrae tissue assays. The most potent form (OCT-TK-III) was not only the most anionically charged but also was the most structurally stable. These results not only reveal that the interaction of tachykinin peptides is more complex than previous structure-function theories envisioned, but also reinforce the fundamental premise that animal venoms are rich resources of novel bioactive molecules, which are useful investigational ligands and some of which may be useful as lead compounds for drug design and development. Copyright © 2013 Elsevier Inc. All rights reserved.

  14. Animal-habitat relationships in the Knysna Forest, South Africa: discrimination between forest types by birds and invertebrates.

    Science.gov (United States)

    Koen, J H; Crowe, T M

    1987-06-01

    Effects of forest plant species composition and physiognomy on bird and invertebrate communities were investigated in three discrete, relatively undisturbed forest types along a dry-wet soil moisture gradient. Using discriminant function analysis, a 100% floristic and a 78% vegetation structural discrimination were obtained between the three forest types. However, the bird communities of these different forest types were very similar in species composition, and had much lower densities than those normally encountered in other, superficially similar forests. Although an 81% discrimination between forest types was attained through analysis of ground surface invertebrates, measures of litter and aerial invertebrate abundance were also of limited use as discriminators. Historical and biogeographic factors, as well as the low nutritional levels in the soil and vegetation may be the causes of low bird and invertebrate density and diversity. It is concluded that floristics and vegetation structure have, at best, a minor influence on bird community structure, and possibly also on invertebrate community structure in the Knysna Forest.

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

    Science.gov (United States)

    2015-12-17

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

  16. 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

  17. Benthic foraminiferal biocoenoses in the estuarine regimes of Goa

    Digital Repository Service at National Institute of Oceanography (India)

    Setty, M.G.A.P.

    Benthic Foraminifera are highly responsive to subtle changes in the estuarine environment. Keeping this in view, a qualitative analysis of living benthic Foraminifera was made of the samples collected from the Mandovi-Zuari estuaries...

  18. 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 (behaviour, and predator-prey interactions and relationships shifted. This nuanced scale of resolution is a useful tool to interpret present benthic community status (behaviour) and past mortalities (community composition, e.g. survival of tolerant species). This information on the sensitivity (onset of stress response), tolerance (mortality, survival), and characteristics (i.e. life habit, functional role) of key species also helps predict

  19. Appendix U: benthic biological studies

    International Nuclear Information System (INIS)

    Hessler, R.R.

    1981-01-01

    Characterization of the biology and standing crop of the benthic organisms is divided into two major categories: (1) those organisms (sessile or with limited mobility) that live on or within the sediment (infauna); and (2) highly mobile organisms that have contact (if only occasionally) with the sediment (benthopelagic organisms). At this time our studies of benthopelagic organisms are restricted to amphipods. The amphipods trapped at MPG-I (30 to 31 0 N, 159 0 W) in 1978 have been sorted to species and compared with those trapped at Climax II (28 0 N, 155 to 156 0 W) in 1977. The species composition is the same at both stations and the numerical representation of the various species appears to be equivalent. Instar categories based on morphological and size criteria have been determined for Eurythenes gryllus. Comparison of the size range of the instar categories, morphological characters and female to male ratio show no detectable differences in E. gryllus from the two areas. Individuals of one of the smaller species of amphipods (Paralicella caperesca) were trapped at 710 m above the sediment, demonstrating that although the primary range of this species is 0-1 m off the bottom, it is capable of wide bathymetric movements. Males mature at a much smaller size (7 cm vs 11.5 cm) than females. Females appear to breed only once while males seem to be reproductively mature for several instars. After attaining maturity, male growth decreases to almost half the previous rate, and the time interval between molts appears to increase substantially. Females approximate a linear growth rate throughout their instar stages. The data are insufficient to determine if a decrease in growth rate occurs at the molt to maturity (female 14). The apparent difference in the time to maturity for males and females results in a high number of mature males present in the population to fertilize relatively few females

  20. 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)

  1. Natural invertebrate hosts of iridoviruses (Iridoviridae)

    International Nuclear Information System (INIS)

    Williams, Trevor

    2008-01-01

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

  2. 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.

  3. Developmental biology in marine invertebrate symbioses.

    Science.gov (United States)

    McFall-Ngai, M J; Ruby, E G

    2000-12-01

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

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

    Science.gov (United States)

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

    2017-01-01

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

  5. 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).

  6. Community shelter use in response to two benthic decapod predators in the Long Island Sound

    Directory of Open Access Journals (Sweden)

    David M. Hudson

    2016-07-01

    Full Text Available 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.

  7. 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

  8. Rapid change with depth in megabenthic structure-forming communities of the Makapu'u deep-sea coral bed

    Science.gov (United States)

    Long, Dustin J.; Baco, Amy R.

    2014-01-01

    Seamounts are largely unexplored undersea mountains rising abruptly from the ocean floor, which can support an increased abundance and diversity of organisms. Deep-sea corals are important benthic structure-formers on current-swept hard substrates in these habitats. While depth is emerging as a factor structuring the fauna of seamounts on a large spatial scale, most work addressing deep-sea coral and seamount community structure has not considered the role of small-scale variation in species distributions. Video from six ROV dives over a depth range of ~320-530 m were analyzed to assess the diversity and density of benthic megafaunal invertebrates across the Makapu'u deep-sea coral bed, offshore of Oahu, Hawaii. At the same time, the physical environment along the dive track was surveyed to relate biotic patterns with abiotic variables including depth, aspect, rugosity, substrate, slope and relief to test the factors structuring community assemblages. Despite the narrow range examined, depth was found to be the strongest structuring gradient, and six unique macrobenthic communities were found, with a 93% faunal dissimilarity over the depth surveyed. Relief, rugosity and slope were also factors in the final model. Alcyonacean octocorals were the dominant macrofaunal invertebrates at all but the deepest depth zone. The commercially harvested precious coral C. secundum was the dominant species at depths 370-470 m, with a distribution that is on average deeper than similar areas. This may be artificial due to the past harvesting of this species on the shallower portion of its range. Primnoid octocorals were the most abundant octocoral family overall. This work yields new insight on the spatial ecology of seamounts, pointing out that community changes can occur over narrow depth ranges and that communities can be structured by small-scale physiography.

  9. Left-right asymmetries of behaviour and nervous system in invertebrates.

    Science.gov (United States)

    Frasnelli, Elisa; Vallortigara, Giorgio; Rogers, Lesley J

    2012-04-01

    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. A variety of studies have revealed sensory and motor asymmetries in behaviour, as well as asymmetries in the nervous system, in invertebrates. Asymmetries in behaviour are apparent in olfaction (antennal asymmetries) and in vision (preferential use of the left or right visual hemifield during activities such as foraging or escape from predators) in animals as different as bees, fruitflies, cockroaches, octopuses, locusts, ants, spiders, crabs, snails, water bugs and cuttlefish. Asymmetries of the nervous system include lateralized position of specific brain structures (e.g., in fruitflies and snails) and of specific neurons (e.g., in nematodes). As in vertebrates, lateralization can occur both at the individual and at the population-level in invertebrates. Theoretical models have been developed supporting the hypothesis that the alignment of the direction of behavioural and brain asymmetries at the population-level could have arisen as a result of social selective pressures, when individually asymmetrical organisms had to coordinate with each other. The evidence reviewed suggests that lateralization at the population-level may be more likely to occur in social species among invertebrates, as well as vertebrates. Copyright © 2012 Elsevier Ltd. All rights reserved.

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

    Science.gov (United States)

    Quist, Michael C.; Schultz, Randall D.

    2014-09-01

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

  11. Habitat modification drives benthic trophic diversity in an intertidal soft-bottom ecosystem

    NARCIS (Netherlands)

    van der Zee, E.M.; Tielens, E.; Holthuijsen, S.; Donadi, S.; Eriksson, B.K.; van der Veer, H.W.; Piersma, T.; Olff, H.; van der Heide, T.

    2015-01-01

    In intertidal soft-bottom ecosystems, ecosystem engineers such as reef-building bivalves, can strongly affect the associated benthic community by providing structure and stabilizing the sediment. Although several engineering species have declined dramatically in the past centuries, the consequences

  12. Relapse to cocaine seeking in an invertebrate.

    Science.gov (United States)

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

    2017-06-01

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

  13. Seasonal variation exceeds effects of salmon carcass additions on benthic food webs in the Elwha River

    Science.gov (United States)

    Morley, S.A.; Coe, H.J.; Duda, J.J.; Dunphy, L.S.; McHenry, M.L.; Beckman, B.R.; Elofson, M.; Sampson, E. M.; Ward, L.

    2016-01-01

    Dam removal and other fish barrier removal projects in western North America are assumed to boost freshwater productivity via the transport of marine-derived nutrients from recolonizing Pacific salmon (Oncorhynchus spp.). In anticipation of the removal of two hydroelectric dams on the Elwha River in Washington State, we tested this hypothesis with a salmon carcass addition experiment. Our study was designed to examine how background nutrient dynamics and benthic food webs vary seasonally, and how these features respond to salmon subsidies. We conducted our experiment in six side channels of the Elwha River, each with a spatially paired reference and treatment reach. Each reach was sampled on multiple occasions from October 2007 to August 2008, before and after carcass placement. We evaluated nutrient limitation status; measured water chemistry, periphyton, benthic invertebrates, and juvenile rainbow trout (O. mykiss) response; and traced salmon-derived nutrient uptake using stable isotopes. Outside of winter, algal accrual was limited by both nitrogen and phosphorous and remained so even in the presence of salmon carcasses. One month after salmon addition, dissolved inorganic nitrogen levels doubled in treatment reaches. Two months after addition, benthic algal accrual was significantly elevated. We detected no changes in invertebrate or fish metrics, with the exception of 15N enrichment. Natural seasonal variability was greater than salmon effects for the majority of our response metrics. Yet seasonality and synchronicity of nutrient supply and demand are often overlooked in nutrient enhancement studies. Timing and magnitude of salmon-derived nitrogen utilization suggest that uptake of dissolved nutrients was favored over direct consumption of carcasses. The highest proportion of salmon-derived nitrogen was incorporated by herbivores (18–30%) and peaked 1–2 months after carcass addition. Peak nitrogen enrichment in predators (11–16%) occurred 2–3

  14. Community structure and trophic ecology of megabenthic fauna from the deep basins in the Interior Sea of Chiloé, Chile (41-43° S)

    Science.gov (United States)

    Zapata-Hernández, Germán; Sellanes, Javier; Thiel, Martin; Henríquez, Camila; Hernández, Sebastián; Fernández, Julio C. C.; Hajdu, Eduardo

    2016-11-01

    Estuarine environments are complex ecological systems, which depend on multiple inputs of organic sources that could support their benthic communities. The deep-water megabenthic communities of the Interior Sea of Chiloé (ISCh, northern part of the fjord region of Chile) were studied to characterize their taxonomic composition and to trace the energy pathways supporting them by using stable isotope analysis (SIA). Megabenthic and demersal organisms as well as sunken macroalgal debris and terrestrial organic matter (TOM: wood, leaves, branches) were obtained by bottom trawling along an estuarine gradient covering 100-460 m water depth. Additionally, particulate organic matter (POM) and the sedimentary organic matter (SOM) were sampled and carbon (δ13C) and nitrogen (δ15N) isotope ratios were determined for all these organisms and potential food sources. A total of 140 taxa were obtained, including invertebrates (e.g. polychaetes, mollusks, crustaceans and echinoderms) bony fishes, rays and sharks. Based on the stable isotope values it was possible to infer a strong dependence on primary production derived from phytoplankton which is exported to the benthos. A potentially important contribution from sunken macroalgae to megabenthic consumers was established only for some invertebrates, such as the irregular echinoid Tripylaster philippii and the decapod Eurypodius latreillii. The trophic structure metrics suggest a similar isotopic niche width, trophic diversity and species packaging in the food webs among the major basins in the ISCh. It is thus concluded that the benthic food webs are supported principally by surface primary production, but macroalgal subsidies could be exploited by selected invertebrate taxa (e.g. detritivores) and terrestrial carbon pathways are important for certain specialized taxa (e.g. Xylophaga dorsalis).

  15. 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.

  16. 50 CFR 17.85 - Special rules-invertebrates.

    Science.gov (United States)

    2010-10-01

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

  17. Invertebrates of the Columbia River basin assessment area.

    Science.gov (United States)

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

    2001-01-01

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

  18. 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...

  19. Coastal Benthic Optical Properties (CoBOP): Optical Properties of Benthic Marine Organisms and Substrates

    National Research Council Canada - National Science Library

    Mazel, Charles

    2002-01-01

    ...). The long-term objective of our research is to gain an understanding of the nature and significance of fluorescence and reflectance characteristics of benthic marine organisms in general, and coral...

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

    Science.gov (United States)

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

    2018-02-01

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

  1. 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.

  2. Invertebrate predation on egg masses of the European cuttlefish, Sepia officinalis: An experimental approach

    Science.gov (United States)

    Martins, Catarina P. P.; Fernández-Álvarez, Fernando Á.; Villanueva, Roger

    2018-01-01

    The eggs of the European cuttlefish, Sepia officinalis, develop attached to the seafloor in shallow water habitats and possess a relatively thick black capsule that protects them from the surrounding environment. Since embryological development may take several months, eggs are vulnerable to a variety of threats present in shallow waters, including predation. This study investigates predation of S. officinalis eggs by benthic invertebrates. Twenty-eight invertebrate species from 6 different phyla and with diverse feeding habits were tested as potential predators under laboratory conditions. We also investigated how the feeding traits of these species are related to the mechanical ability to break the egg capsule and prey upon cuttlefish embryos. Species that fed on cuttlefish eggs were the sea snail Bolinus brandaris, the crab Cancer pagurus, the hermit crab Dardanus arrosor, the lobster Homarus gammarus, the invasive blue crab Callinectes sapidus, the shrimp Squilla mantis, the sea urchins Echinus melo, Cidaris sp. and Paracentrotus lividus and the starfish Astropecten aranciacus. It is of note that C. sapidus is a potential predatory crab, which raises the concern that this invasive species may constitute a novel threat for cuttlefish eggs as more populations become established in NE Atlantic waters. Of the biological traits examined, prey capture tools in the tested species best explained the experimental feeding results, suggesting that predation of S. officinalis eggs was determined generally by a mechanical factor and highlighting the importance of the protective egg capsule against predators. However, chemosensory factors are likely to be implicated as well. Thus, this work contributes to the understanding of the ecology of early life stages of cuttlefish and the factors that can affect offspring survival and subsequently impact the recruitment of this species.

  3. 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

  4. Deposition and benthic mineralization of organic carbon

    DEFF Research Database (Denmark)

    Nordi, Gunnvor A.; Glud, Ronnie N.; Simonsen, Knud

    2018-01-01

    Seasonal variations in sedimentation and benthic mineralization of organic carbon (OC) were investigated in a Faroese fjord. Deposited particulate organic carbon (POC) was mainly of marine origin, with terrestrial material only accounting for b1%. On an annual basis the POC export fromthe euphotic...

  5. Evaluation of some Physicochemical Parameters and Benthic ...

    African Journals Online (AJOL)

    ADOWIE PERE

    studied to assess the impact of anthropogenic activities on this man-made lake by collecting surface water and benthic samples. ... activities like domestic and industrial (Banetti and. Garrido, 2010). ... of organic matter and also in assessing the quality of ... Ogun River. ... wastes waters from washing of clothes, sewage.

  6. Microplastic effect thresholds for freshwater benthic macroinvertebrates

    NARCIS (Netherlands)

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

    2018-01-01

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

  7. Benthic carbon mineralization in hadal trenches

    DEFF Research Database (Denmark)

    Wenzhofer, F.; Oguri, K.; Middelboe, M.

    2016-01-01

    Hadal trenches are considered to act as depo-centers for organic material at the trench axis and host unique and elevated biomasses of living organisms as compared to adjacent abyssal plains. To explore the diagenetic activity in hadal trench environments we quantified in situ benthic O-2 consump...

  8. Benthic freshwater nematode community dynamics under conditions ...

    African Journals Online (AJOL)

    Studies of the influence of fish aquaculture on benthic freshwater nematode assemblages are scarce, but could provide a way of gauging environmental effects. The abundance and diversity of nematode assemblages in response to Oreochromis niloticus aquaculture were investigated in Kafr El-Sheikh Governorate, Egypt, ...

  9. Biodiversity effects of benthic ecosystem engineers on the spatial patterns of sediment CH4 concentration in an urban Neotropical coastal lagoon

    Directory of Open Access Journals (Sweden)

    Adriano Caliman

    Full Text Available AIM: Biodiversity of sediment bioturbators has been shown to be important for to the magnitude and stability of benthic-pelagic processes. However, no study to date has evaluated the importance of the biodiversity of benthic invertebrate bioturbators to the spatial patterns of sediment CH4 concentration ([CH4]. Here we conducted a laboratorial experiment to test the following predictions: (1 Bioturbator species richness will reduce the sediment [CH4]; (2 individual bioturbator species (i.e. species composition will have different effects on sediment [CH4]; (3 and both the effects of bioturbator species richness and composition on sediment [CH4] will be dependent on sediment depth. METHODS: We manipulated the number and composition of three functional divergent benthic invertebrate bioturbators species that are widespread in South Atlantic coastal lagoons, in laboratorial sediment chambers containing the sediment and water of an urban impacted coastal lagoon RESULTS: Bioturbator species richness had no overall significant effect on sediment [CH4] when comparisons of sediment [CH4] were made among species richness levels. However, bioturbator species richness significantly reduced sediment [CH4] when species richness levels were compared to the control (defaunated treatments, but this effect was significant only at the deepest sediment layer. Furthermore, bioturbator species composition had significant, but distinct effects on the patterns of reduction in sediment [CH4], depending on the sediment depth and the bioturbator species. CONCLUSIONS: We conclude that both the number and composition of bioturbator species are important to determine the effects of benthic bioturbators on spatial patterns of sediment [CH4], but the strength of these effects depend on species traits that determine interspecific interactions strength across the sediment vertical niche space.

  10. 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.

  11. The importance of benthic-pelagic coupling for marine ecosystem functioning in a changing world.

    Science.gov (United States)

    Griffiths, Jennifer R; Kadin, Martina; Nascimento, Francisco J A; Tamelander, Tobias; Törnroos, Anna; Bonaglia, Stefano; Bonsdorff, Erik; Brüchert, Volker; Gårdmark, Anna; Järnström, Marie; Kotta, Jonne; Lindegren, Martin; Nordström, Marie C; Norkko, Alf; Olsson, Jens; Weigel, Benjamin; Žydelis, Ramunas; Blenckner, Thorsten; Niiranen, Susa; Winder, Monika

    2017-06-01

    Benthic-pelagic coupling is manifested as the exchange of energy, mass, or nutrients between benthic and pelagic habitats. It plays a prominent role in aquatic ecosystems, and it is crucial to functions from nutrient cycling to energy transfer in food webs. Coastal and estuarine ecosystem structure and function are strongly affected by anthropogenic pressures; however, there are large gaps in our understanding of the responses of inorganic nutrient and organic matter fluxes between benthic habitats and the water column. We illustrate the varied nature of physical and biological benthic-pelagic coupling processes and their potential sensitivity to three anthropogenic pressures - climate change, nutrient loading, and fishing - using the Baltic Sea as a case study and summarize current knowledge on the exchange of inorganic nutrients and organic material between habitats. Traditionally measured benthic-pelagic coupling processes (e.g., nutrient exchange and sedimentation of organic material) are to some extent quantifiable, but the magnitude and variability of biological processes are rarely assessed, preventing quantitative comparisons. Changing oxygen conditions will continue to have widespread effects on the processes that govern inorganic and organic matter exchange among habitats while climate change and nutrient load reductions may have large effects on organic matter sedimentation. Many biological processes (predation, bioturbation) are expected to be sensitive to anthropogenic drivers, but the outcomes for ecosystem function are largely unknown. We emphasize how improved empirical and experimental understanding of benthic-pelagic coupling processes and their variability are necessary to inform models that can quantify the feedbacks among processes and ecosystem responses to a changing world. © 2017 The Authors. Global Change Biology Published by John Wiley & Sons Ltd.

  12. Multiscale patterns in the diversity and organization of benthic intertidal fauna among French Atlantic estuaries

    Science.gov (United States)

    Blanchet, Hugues; Gouillieux, Benoît; Alizier, Sandrine; Amouroux, Jean-Michel; Bachelet, Guy; Barillé, Anne-Laure; Dauvin, Jean-Claude; de Montaudouin, Xavier; Derolez, Valérie; Desroy, Nicolas; Grall, Jacques; Grémare, Antoine; Hacquebart, Pascal; Jourde, Jérôme; Labrune, Céline; Lavesque, Nicolas; Meirland, Alain; Nebout, Thiebaut; Olivier, Frédéric; Pelaprat, Corine; Ruellet, Thierry; Sauriau, Pierre-Guy; Thorin, Sébastien

    2014-07-01

    Based on a parallel sampling conducted during autumn 2008, a comparative study of the intertidal benthic macrofauna among 10 estuarine systems located along the Channel and Atlantic coasts of France was performed in order to assess the level of fauna similarity among these sites and to identify possible environmental factors involved in the observed pattern at both large (among sites) and smaller (benthic assemblages) scales. More precisely this study focused on unraveling the observed pattern of intertidal benthic fauna composition and diversity observed at among-site scale by exploring both biotic and abiotic factors acting at the among- and within-site scales. Results showed a limited level of similarity at the among-site level in terms of intertidal benthic fauna composition and diversity. The observed pattern did not fit with existing transitional water classification methods based on fish or benthic assemblages developed in the frame of the European Water Framework Directive (WFD). More particularly, the coastal plain estuaries displayed higher among-site similarity compared to ria systems. These coastal plain estuaries were characterized by higher influence of river discharge, lower communication with the ocean and high suspended particulate matter levels. On the other hand, the ria-type systems were more dissimilar and different from the coastal plain estuaries. The level of similarity among estuaries was mainly linked to the relative extent of the intertidal "Scrobicularia plana-Cerastoderma edule" and "Tellina tenuis" or "Venus" communities as a possible consequence of salinity regime, suspended matter concentrations and fine particles supply with consequences on the trophic functioning, structure and organization of benthic fauna. Despite biogeographical patterns, the results also suggest that, in the context of the WFD, these estuaries should only be compared on the basis of the most common intertidal habitat occurring throughout all estuarine systems

  13. Benthic Foraminifera, Food in the Deep Sea, and Limits to Bentho-Pelagic Coupling

    Science.gov (United States)

    Thomas, E.; Boscolo-Galazzo, F.; Arreguin-Rodrigu, G. J.; Ortiz, S.; Alegret, L.

    2015-12-01

    The deep-sea is the largest habitat on Earth, contains highly diverse biota, but is very little known. Many of its abundant benthic biota (e.g., nematodes) are not preserved in the fossil record. Calcareous and agglutinated benthic foraminifera (unicellular eukaryotes, Rhizaria; efficient dispersers) and ostracodes (Animalia, Crustacea; non-efficient dispersers) are the most common organisms providing a fossil record of deep-sea environments. Very little food is supplied to the deep-sea, because organic matter produced by photosynthesis is largely degraded before it arrives at the seafloor. Only a few % of organic matter is carried to the ocean bottom by 'marine snow', with its particle size and behavior in the water column controlled by surface ecosystem structure, including type of dominant primary producers (diatoms, cyanobacteria). Food supply and its seasonality are generally seen as the dominant control on benthic assemblages (combined with oxygenation), providing bentho-pelagic coupling between primary and benthic productivity. Benthic foraminiferal assemblages (composition and density) thus are used widely to estimate past productivity, especially during episodes of global climate change, ocean acidification, and mass extinction of primary producers. We show that some environmental circumstances may result in interrupting bentho-pelagic coupling, e.g. through lateral supply of organic matter along continental margins (adding more refractory organic matter), through trophic focusing and/or fine particle winnowing on seamounts (giving an advantage to suspension feeders), and through carbonate undersaturation (giving advantage to infaunal over epifaunal calcifyers). In addition, increased remineralization of organic matter combined with increased metabolic rates may cause assemblages to reflect more oligotrophic conditions at stable primary productivity during periods of global warming. As a result, benthic foraminiferal accumulation rates must be carefully

  14. NOAA Point Shapefile- Benthic Habitat Classifications from Minibat ROV Underwater Video, US Virgin Islands, Project NF-04-06, 2004, 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. 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

  16. Benthic ecological status of Algerian harbours.

    Science.gov (United States)

    Dauvin, J C; Bakalem, A; Baffreau, A; Grimes, S

    2017-12-15

    This work is an overview of all available benthic data collected in the Algerian harbours between 1983 and 2001. So, total of 571 stations were reported in the 10 major Algerian harbours along the Algerian coast (1200km). Two main categories of harbours were distinguished according to their hydrodynamic regime and volume of water exchange between inner harbour basins and the entrance of the harbours. Univariate, multivariate, benthic indices and Biological Traits of Life approaches were applied on stations sampled in the late 1990s and long-term observations in six out of these ten harbours. These approaches assessed the main characteristics and ecological statuses from these south Mediterranean harbours. One of the main characteristics of the Algerian harbours was the very high species diversity (847 species). Although all the fauna was dominated by pollution-tolerant species; some harbours such as Bethioua and Djendjen hosted normal benthic communities as found in the open sea, but also included some pollution indicator species typical of a slight polluted system. On the contrary, the newly constructed port of Skikda showed perturbed benthic communities in relation to hydrocarbon pollution. Biological Traits of Life analysis reinforced the separation of benthic species along a gradient reflecting their sensitivity or tolerance to pollution. This response was related to an increase in organic matter content, probably associated with a general organic and metal contamination, from the entrance of the harbour to the innermost basins in areas with weak circulation, high sedimentation rate and concentrations of pollutants. Except for Oran harbour, where the poor to moderate ecological status remained unchanged with time, the other harbours showed an improvement or a slight degradation. A strategy of long-term monitoring should be promoted, based on a restricted and selected number of stations characteristic of the different basins and water masses occupying the

  17. Comparability among four invertebrate sampling methods and two multimetric indexes, Fountain Creek Basin, Colorado, 2010–2012

    Science.gov (United States)

    Bruce, James F.; Roberts, James J.; Zuellig, Robert E.

    2018-05-24

    The U.S. Geological Survey (USGS), in cooperation with Colorado Springs City Engineering and Colorado Springs Utilities, analyzed previously collected invertebrate data to determine the comparability among four sampling methods and two versions (2010 and 2017) of the Colorado Benthic Macroinvertebrate Multimetric Index (MMI). For this study, annual macroinvertebrate samples were collected concurrently (in space and time) at 15 USGS surface-water gaging stations in the Fountain Creek Basin from 2010 to 2012 using four sampling methods. The USGS monitoring project in the basin uses two of the methods and the Colorado Department of Public Health and Environment recommends the other two. These methods belong to two distinct sample types, one that targets single habitats and one that targets multiple habitats. The study results indicate that there are significant differences in MMI values obtained from the single-habitat and multihabitat sample types but methods from each program within each sample type produced comparable values. This study also determined that MMI values calculated by different versions of the Colorado Benthic Macroinvertebrate MMI are indistinguishable. This indicates that the Colorado Department of Public Health and Environment methods are comparable with the USGS monitoring project methods for single-habitat and multihabitat sample types. This report discusses the direct application of the study results to inform the revision of the existing USGS monitoring project in the Fountain Creek Basin.

  18. Influence of fruit and invertebrate consumption on the gut microbiota of wild white-faced capuchins (Cebus capucinus).

    Science.gov (United States)

    Mallott, Elizabeth K; Amato, Katherine R; Garber, Paul A; Malhi, Ripan S

    2018-03-01

    Invertebrate consumption is thought to be an integral part of early hominin diets, and many modern human populations regularly consume insects and other arthropods. This study examines the response of gut microbial community structure and function to changes in diet in wild white-faced capuchins (Cebus capucinus), a primate that incorporates a large proportion of invertebrates in its diet. The goal of the study is to better understand the role of both fruit and invertebrate prey consumption on shaping primate gut microbiomes. Fecal samples (n = 169) and dietary data were collected over 12 months. The V3-V5 region of microbial 16S rRNA genes was amplified and sequenced. The IM-TORNADO pipeline was used to analyze sequences. White-faced capuchin gut bacterial communities were characterized primarily by Firmicutes (41.6%) and Proteobacteria (39.2%). There was a significant relationship between the invertebrate diet composition of individual capuchins and their gut microbiome composition